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Cuba Cardiology Specialty - independent subject foundations study materials
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Cuba Cardiology Specialty - independent subject foundations practice questions

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Question 1Coronary disease, infarction and cardiovascular emergencies

A 62-year-old woman with an extensive anterior STEMI received full-dose fibrinolysis with recombinant streptokinase 90 minutes ago. She continues to experience severe diaphoresis and 8/10 chest pain. Her repeat 12-lead ECG shows persistent 5 mm ST-segment elevation in leads V1 through V4, representing less than 20% resolution from baseline. What is the recommended management at this stage?

  1. Readministration of a second full dose of streptokinase immediately
  2. Immediate emergent transfer for rescue percutaneous coronary intervention (PCI) Correct answer.
  3. Intravenous administration of therapeutic-dose unfractionated heparin without invasive intervention
  4. Oral administration of high-dose diltiazem to relieve potential microvascular spasm

Explanation

Failed reperfusion following fibrinolysis is defined as persistent ischemic chest pain and less than 50% resolution of the maximal ST-segment elevation on ECG at 60 to 90 minutes post-infusion. The standard of care endorsed by Cuban and international cardiology guidelines is immediate rescue PCI. Readministering streptokinase is contraindicated due to the rapid formation of neutralizing anti-streptokinase antibodies and allergic risk.

Question 2Coronary disease, infarction and cardiovascular emergencies

A 65-year-old male with hypertension and dyslipidemia undergoes successful primary percutaneous coronary intervention with a drug-eluting stent (DES) in the proximal left anterior descending coronary artery for acute STEMI. He has no history of bleeding or oral anticoagulant indication. What is the standard guideline-recommended duration of dual antiplatelet therapy (DAPT)?

  1. Lifelong dual antiplatelet therapy with high-dose aspirin and clopidogrel
  2. 1 month of aspirin plus clopidogrel followed by lifelong clopidogrel monotherapy
  3. 3 months of aspirin plus clopidogrel followed by discontinuation of all antiplatelet agents
  4. 12 months of aspirin plus a P2Y12 inhibitor (such as clopidogrel) Correct answer.

Explanation

Standard clinical guidelines from the Sociedad Cubana de Cardiología and international consensus recommend 12 months of dual antiplatelet therapy (DAPT) consisting of aspirin (81-100 mg daily) combined with a P2Y12 platelet receptor inhibitor (clopidogrel 75 mg daily, or ticagrelor/prasugrel where available) following acute coronary syndromes treated with DES, provided the patient is not at excessive bleeding risk.

Question 3Coronary disease, infarction and cardiovascular emergencies

A 71-year-old male with prior diabetes mellitus presents with rest angina. His ECG shows 1.5 mm horizontal ST-segment depression in leads V4 to V6 and elevated high-sensitivity troponin T. His GRACE risk score is calculated at 148, placing him in the high-risk category for non-ST elevation acute coronary syndrome (SCASEST). What is the recommended invasive timing strategy according to clinical guidelines?

  1. Immediate emergent angiography within 2 hours regardless of clinical stabilization
  2. Early invasive coronary angiography within 24 hours of hospital admission Correct answer.
  3. Conservative non-invasive strategy with outpatient treadmill exercise testing next week
  4. Delayed elective angiography only if symptoms recur after 7 days of triple therapy

Explanation

In non-ST elevation acute coronary syndromes (SCASEST), patients with high-risk criteria-such as a GRACE score > 140, dynamic ST-T wave changes, or established rise in cardiac troponins-benefit from an early invasive strategy, defined as coronary angiography and revascularization within 24 hours of presentation. An immediate invasive strategy (<2 hours) is reserved for very-high-risk patients (refractory angina, cardiogenic shock, life-threatening arrhythmias, or acute heart failure).

Question 4Coronary disease, infarction and cardiovascular emergencies

On the fourth day following an extensive anterior myocardial infarction, a 68-year-old patient develops sudden severe dyspnea, diaphoresis, and hypotension (BP 75/45 mmHg). Cardiac auscultation reveals a new, harsh, holosystolic murmur heard best along the left lower sternal border accompanied by a palpable systolic thrill. Right heart catheterization demonstrates an oxygen saturation jump from 62% in the right atrium to 84% in the right ventricle. What is the definitive diagnosis?

  1. Free wall rupture with localized pseudoaneurysm formation
  2. Acute rupture of the posteromedial papillary muscle
  3. Post-infarction ventricular septal rupture (VSR) Correct answer.
  4. Severe acute ischemic tricuspid valve avulsion

Explanation

Ventricular septal rupture (VSR) is a catastrophic mechanical complication occurring 3 to 5 days after transmural infarction. Clinical hallmarks include sudden cardiogenic shock, a loud harsh holosystolic murmur with a thrill at the left parasternal border, and an oxygen saturation step-up of >= 8-10% between the right atrium and right ventricle on oximetry due to left-to-right shunting. Definitive management requires urgent surgical or transcatheter closure.

Question 5Coronary disease, infarction and cardiovascular emergencies

A 64-year-old patient with an acute posterolateral myocardial infarction suddenly develops flash pulmonary edema and cardiogenic shock on day 3. Auscultation reveals a soft, early-to-mid systolic murmur at the cardiac apex. Bedside transthoracic echocardiography is limited by poor acoustic windows. Which mechanical complication is most likely, and which anatomical structure is specifically vulnerable due to its solitary blood supply?

  1. Rupture of the anterolateral papillary muscle supplied solely by the right coronary artery
  2. Ventricular septal rupture of the muscular septum supplied solely by diagonal branches
  3. Aortic valve leaflet prolapse caused by ischemia of the left non-coronary cusp
  4. Acute mitral regurgitation due to rupture of the posteromedial papillary muscle supplied solely by the posterior descending artery Correct answer.

Explanation

The posteromedial papillary muscle has a solitary arterial blood supply, usually originating from the posterior descending artery (arising from the RCA in right-dominant or LCx in left-dominant systems), making it much more vulnerable to ischemic necrosis and rupture than the anterolateral papillary muscle, which receives dual blood supply from both the LAD and LCx. Rupture precipitates torrential acute mitral regurgitation, pulmonary edema, and cardiogenic shock requiring urgent surgical intervention.

Question 6Coronary disease, infarction and cardiovascular emergencies

During evaluation of a patient who suffered an inferior myocardial infarction 3 weeks ago, an echocardiogram detects a localized, saccular outpouching of the left ventricular inferolateral wall. The neck of the outpouching measures 1.2 cm, while the maximal internal diameter of the cavity measures 3.8 cm (orifice-to-cavity ratio < 0.5), with evidence of pericardial adhesions and turbulent bidirectional flow by color Doppler. What is the diagnosis and appropriate management?

  1. Left ventricular pseudoaneurysm; urgent surgical repair is indicated due to high risk of catastrophic rupture Correct answer.
  2. True left ventricular aneurysm; conservative medical management with anticoagulation and afterload reduction
  3. Takotsubo cardiomyopathy with apical ballooning; supportive therapy and repeat echo in 4 weeks
  4. Pericardial cyst; reassurance and routine follow-up with no intervention required

Explanation

A left ventricular pseudoaneurysm (false aneurysm) forms when a localized free wall rupture is contained by adherent parietal pericardium and organized thrombus. Morphologically, it is characterized by a narrow neck whose orifice dimension is less than 50% of the maximal cavity diameter, in contrast to a true aneurysm which features a wide neck containing myocardium. Because pseudoaneurysms carry a high propensity for sudden, fatal rupture regardless of size, urgent surgical repair is indicated.

Question 7Coronary disease, infarction and cardiovascular emergencies

According to the Killip-Kimball clinical classification of acute myocardial infarction, how is a patient classified who presents with frank pulmonary edema, bilateral widespread inspiratory crackles extending past the mid-lung zones, and severe tachypnea, but maintains a systolic blood pressure of 115/75 mmHg?

  1. Killip Class II
  2. Killip Class III Correct answer.
  3. Killip Class I
  4. Killip Class IV

Explanation

The Killip-Kimball classification stratifies post-infarction heart failure severity: Killip I denotes absence of clinical heart failure; Killip II denotes mild-to-moderate heart failure with basilar crackles (<50% of lung fields) and/or an S3 gallop; Killip III denotes frank acute pulmonary edema with rales in >50% of lung fields; and Killip IV denotes cardiogenic shock (systolic BP < 90 mmHg with signs of hypoperfusion).

Question 8Coronary disease, infarction and cardiovascular emergencies

A 69-year-old female in the coronary intensive care unit develops post-infarction cardiogenic shock with a blood pressure of 74/46 mmHg, heart rate of 108 bpm, cold clammy extremities, and anuria. Pulmonary artery catheterization confirms a cardiac index of 1.6 L/min/m2 and a pulmonary capillary wedge pressure (PCWP) of 24 mmHg. What is the vasopressor agent of first choice to restore mean arterial pressure?

  1. Phenylephrine
  2. Dopamine at high doses (> 15 mcg/kg/min)
  3. Norepinephrine Correct answer.
  4. Isoproterenol

Explanation

In cardiogenic shock with severe hypotension, norepinephrine is the initial vasopressor of choice based on clinical trials (including the SOAP II trial) and international guidelines. It restores coronary and systemic perfusion pressure via potent alpha-1 vasoconstriction with modest beta-1 inotropic support, while causing significantly fewer tachyarrhythmias and lower mortality compared to dopamine.

Question 9Coronary disease, infarction and cardiovascular emergencies

Which of the following clinical conditions represents an absolute contraindication to the administration of fibrinolytic therapy in an adult patient with acute ST-segment elevation myocardial infarction?

  1. Refractory arterial hypertension on presentation with blood pressure of 165/95 mmHg
  2. History of ischemic stroke 9 months ago
  3. Current treatment with therapeutic oral vitamin K antagonists with an INR of 1.4
  4. Prior intracerebral hemorrhage at any time in the patient's life Correct answer.

Explanation

Any history of prior intracerebral hemorrhage or hemorrhagic stroke of unknown origin at any time is an absolute contraindication to fibrinolytic therapy due to the unacceptable risk of fatal recurrent intracranial bleeding. Other absolute contraindications include known cerebral vascular malformation or neoplasm, ischemic stroke within the preceding 6 months (excluding acute within 4.5 hours), active internal bleeding, and suspected aortic dissection.

Question 10Coronary disease, infarction and cardiovascular emergencies

A 74-year-old patient with chronic kidney disease (baseline creatinine 2.1 mg/dL) presents to the emergency department with epigastric discomfort. A high-sensitivity cardiac troponin T assay is mildly elevated at 28 ng/L (upper reference limit 14 ng/L). According to the Universal Definition of Myocardial Infarction, what is required to substantiate an acute myocardial infarction rather than chronic myocardial injury?

  1. Demonstration of a dynamic rise and/or fall of cardiac troponin values with at least one value above the 99th percentile, accompanied by clinical or ECG evidence of ischemia Correct answer.
  2. A single troponin value exceeding twice the upper reference limit without repeat testing
  3. Normal serum creatinine levels following intravenous hydration
  4. Complete normalization of troponin levels within 2 hours of presentation

Explanation

Under the Fourth Universal Definition of Myocardial Infarction, the diagnosis of acute MI requires a dynamic change (rise and/or fall) in cardiac troponin with at least one value above the 99th percentile upper reference limit, alongside at least one clinical criterion (ischemic symptoms, new ischemic ECG changes, pathological Q waves, or imaging evidence of new loss of viable myocardium). In chronic kidney disease, chronically elevated stable troponins reflect chronic myocardial injury unless a significant delta (e.g. >20% change) is documented.

Question 11Coronary disease, infarction and cardiovascular emergencies

A 46-year-old female smoker wakes up repeatedly at 04:00 AM with severe retrosternal squeezing chest pain accompanied by diaphoresis. An ECG recorded during pain displays transient 3 mm ST-segment elevation in leads V2 through V5, which completely resolves within 15 minutes following sublingual nitroglycerin administration. Coronary angiography demonstrates non-obstructive coronary arteries. What is the first-line long-term pharmacological therapy for this condition?

  1. Non-selective beta-blockers (such as propranolol)
  2. Calcium channel blockers (such as diltiazem or amlodipine) Correct answer.
  3. High-dose aspirin combined with clopidogrel for 12 months
  4. Routine oral flecainide therapy

Explanation

This clinical scenario represents vasospastic angina (Prinzmetal angina), characterized by nocturnal or early-morning rest angina with transient ST-segment elevation secondary to epicardial coronary artery spasm. Calcium channel blockers (diltiazem, verapamil, or amlodipine) are the foundation of first-line preventive therapy, often combined with long-acting nitrates. Beta-blockers, particularly non-selective agents, are contraindicated because blocking beta-2 vasodilatory receptors leaves alpha-1 mediated vasoconstriction unopposed, worsening coronary spasm.

Question 12Coronary disease, infarction and cardiovascular emergencies

A 52-year-old female presents with acute retrosternal chest pain, dynamic anterior T-wave inversions, and elevated troponin I (1.8 ng/mL). Emergent coronary angiography reveals smooth coronary vessels with 0% luminal stenosis in all epicardial arteries. Left ventriculography and cardiac magnetic resonance imaging (CMR) are planned. Which diagnostic category encompasses this presentation, and what is the primary diagnostic value of CMR in this setting?

  1. Type 4a myocardial infarction; CMR is used to detect periprocedural side-branch microembolization
  2. Stable microvascular angina; CMR is primarily used to measure the coronary flow reserve of the epicardial vessels
  3. MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries); CMR differentiates subendocardial ischemic infarction from acute myocarditis or Takotsubo cardiomyopathy Correct answer.
  4. Atypical non-cardiac chest pain; CMR is used exclusively to rule out hiatal hernia

Explanation

MINOCA (Myocardial Infarction with Non-Obstructive Coronary Arteries) is defined by universal MI criteria with no epicardial stenosis >= 50% on angiography and no alternative non-ischemic clinical diagnosis at presentation. Cardiac magnetic resonance (CMR) is the imaging modality of choice, as late gadolinium enhancement (LGE) distribution distinguishes subendocardial ischemic injury from subepicardial/mid-wall LGE characteristic of myocarditis or absence of LGE characteristic of Takotsubo syndrome.

Question 13Coronary disease, infarction and cardiovascular emergencies

A 61-year-old male with poorly controlled type 2 diabetes mellitus and stable angina undergoes diagnostic coronary angiography. The angiogram demonstrates severe three-vessel disease involving the bifurcation of the left anterior descending and circumflex arteries, with a calculated SYNTAX score of 36. Left ventricular ejection fraction is 45%. What is the preferred revascularization modality according to current evidence?

  1. Intensive medical therapy alone without any revascularization consideration
  2. Multivessel percutaneous coronary intervention with first-generation bare-metal stents
  3. Single-vessel PCI of the culprit lesion only with medical therapy for the remaining vessels
  4. Coronary artery bypass grafting (CABG) surgery Correct answer.

Explanation

In diabetic patients with multivessel coronary artery disease and complex coronary anatomy (high SYNTAX score > 32), major randomized trials (FREEDOM, SYNTAX) and clinical guidelines demonstrate that CABG provides superior long-term survival, reduced myocardial infarction rates, and lower repeat revascularization compared to PCI.

Question 14Coronary disease, infarction and cardiovascular emergencies

A 55-year-old man undergoes a diagnostic treadmill exercise test using the standard Bruce protocol for exertional chest tightness. During stage 1 (at 2 minutes, workload < 5 METs), he develops 2.5 mm planar ST-segment depression in leads II, III, aVF, and V4-V6, accompanied by a 15 mmHg decrease in systolic blood pressure below baseline and typical angina. What is the interpretation of this stress test result?

  1. High-risk exercise test result indicating extensive myocardial ischemia and poor prognosis Correct answer.
  2. Normal physiological response to graded physical exercise
  3. Low-risk result suitable for continuation of routine outpatient lifestyle modification alone
  4. Uninterpretable test requiring immediate pulmonary function testing

Explanation

High-risk features on exercise stress testing include: onset of significant ST-segment depression (>1 mm) at low workloads (<5 METs or stage 1 of Bruce protocol), ST depression in multiple leads (>= 5 leads), persistent ST depression > 5 minutes into recovery, exertional hypotension (drop in systolic BP below baseline), or exercise-induced sustained ventricular tachyarrhythmias. Such findings indicate severe multivessel or left main disease and warrant prompt invasive coronary angiography.

Question 15Coronary disease, infarction and cardiovascular emergencies

A routine predischarge echocardiogram in a 54-year-old patient following an extensive anterior STEMI reveals apical akinesis with a 1.5 x 2.0 cm protruding, echodense, mobile mass adherent to the apical endocardium, consistent with a left ventricular mural thrombus. What is the standard management to prevent systemic thromboembolism?

  1. Aspirin monotherapy with no systemic anticoagulation required
  2. Immediate emergent open ventriculotomy and surgical thrombectomy
  3. Intravenous thrombolysis with recombinant streptokinase infusion directly into the left ventricle
  4. Therapeutic oral anticoagulation for 3 to 6 months with repeat echocardiographic reassessment Correct answer.

Explanation

Left ventricular thrombus formation occurs predominantly following large anterior STEMIs with apical akinesis or aneurysm. The recommended management is therapeutic oral anticoagulation (vitamin K antagonist with target INR 2.0-3.0 or an approved DOAC) for a duration of 3 to 6 months, guided by repeat imaging demonstrating thrombus resolution and recovery of apical wall motion.

Question 16Coronary disease, infarction and cardiovascular emergencies

A 57-year-old patient who underwent successful PCI with a drug-eluting stent to the proximal circumflex artery 6 days ago presents with sudden, crushing substernal chest pain, diaphoresis, and new 3 mm ST elevation in leads I, aVL, and V6. Coronary angiogram demonstrates complete 100% in-stent thrombotic occlusion. Which factor is the strongest and most frequent predictor of early acute or subacute stent thrombosis?

  1. Premature cessation or non-adherence to prescribed dual antiplatelet therapy (DAPT) Correct answer.
  2. Daily intake of low-dose statin therapy
  3. Physical rehabilitation within 7 days of stent placement
  4. High baseline serum high-density lipoprotein (HDL) cholesterol

Explanation

Premature discontinuation of, or non-compliance with, dual antiplatelet therapy (DAPT) is the single most powerful clinical predictor of acute (<24 hours) and subacute (1 to 30 days) stent thrombosis. Other contributing factors include stent underexpansion, malapposition, edge dissection, and diabetes mellitus.

Question 17Coronary disease, infarction and cardiovascular emergencies

Which of the following statements accurately characterizes the underlying pathophysiological mechanism of chronic secondary (functional) ischemic mitral regurgitation?

  1. Direct bacterial destruction of the chordae tendineae and perforation of the posterior leaflet
  2. Adverse left ventricular remodeling causes displacement of papillary muscles, leading to leaflet tethering and incomplete systolic closure with structurally normal leaflets Correct answer.
  3. Primary fibroelastic deficiency resulting in spontaneous chordal rupture and leaflet flail
  4. Valvular commissural fusion and severe dystrophic leaflet calcification secondary to acute rheumatic carditis

Explanation

Secondary (functional) ischemic mitral regurgitation occurs in the setting of anatomically normal valve leaflets and chordae. It is caused by adverse ischemic left ventricular geometric remodeling-specifically regional wall motion abnormalities, LV dilatation, and apical/lateral displacement of the papillary muscles-which exerts tethering forces on the mitral leaflets, preventing complete systolic coaptation.

Question 18Heart failure, cardiomyopathy and pericardial disease

A 62-year-old male is diagnosed with heart failure with reduced ejection fraction (HFrEF; LVEF 28%). What are the four foundational pharmacological drug classes ('four pillars') proven to reduce all-cause mortality that should be initiated and titrated in patients with chronic HFrEF?

  1. An ARNI (or ACE inhibitor/ARB), an evidence-based beta-blocker, a mineralocorticoid receptor antagonist (MRA), and an SGLT2 inhibitor Correct answer.
  2. Digoxin, furosemide, hydralazine, and amlodipine
  3. A non-dihydropyridine calcium channel blocker, an ARB, aspirin, and isosorbide dinitrate
  4. Spironolactone, milrinone, warfarin, and hydrochlorothiazide

Explanation

The contemporary guideline-directed medical therapy (GDMT) for chronic HFrEF is built upon four foundational pillars: (1) Angiotensin receptor-neprilysin inhibitor (ARNI, sacubitril/valsartan) or ACEi/ARB; (2) Evidence-based beta-blocker (carvedilol, metoprolol succinate, or bisoprolol); (3) Mineralocorticoid receptor antagonist (MRA, spironolactone or eplerenone); and (4) SGLT2 inhibitor (dapagliflozin or empagliflozin). Each drug class provides incremental mortality and hospitalization reduction.

Question 19Heart failure, cardiomyopathy and pericardial disease

When transitioning a patient with chronic HFrEF from an oral ACE inhibitor (such as enalapril) to an angiotensin receptor-neprilysin inhibitor (ARNI, sacubitril/valsartan), what is the mandatory safety precaution regarding dosing interval?

  1. Immediate simultaneous co-administration of full doses of both drugs for 2 weeks
  2. A minimum 36-hour washout period after the last dose of the ACE inhibitor before starting sacubitril/valsartan to prevent life-threatening angioedema Correct answer.
  3. A 6-week gradual downward titration of the ACE inhibitor while simultaneously escalating the ARNI
  4. No washout period is required, and the first dose of ARNI can be taken at the next scheduled dosing time

Explanation

Because both ACE inhibitors and neprilysin degrade bradykinin, concomitant administration or overlapping of an ACE inhibitor with a neprilysin inhibitor causes massive bradykinin accumulation and greatly increases the risk of severe, potentially fatal angioedema. A strict 36-hour washout period between the last dose of an ACE inhibitor and the first dose of sacubitril/valsartan is mandatory.

Question 20Heart failure, cardiomyopathy and pericardial disease

A 72-year-old female presents with exertional breathlessness. Transthoracic echocardiography shows a left ventricular ejection fraction of 56%, concentric LV remodeling, an average E/e' ratio of 16, a septal e' velocity of 6.2 cm/s, and a left atrial volume index (LAVI) of 39 mL/m2. Her serum NT-proBNP is 720 pg/mL in sinus rhythm. According to the HFA-PEFF diagnostic algorithm, what is the most appropriate diagnosis?

  1. Severe non-ischemic dilated cardiomyopathy
  2. Heart failure with preserved ejection fraction (HFpEF) Correct answer.
  3. Isolated severe acute primary tricuspid regurgitation
  4. Normal physiological cardiac aging without evidence of diastolic dysfunction

Explanation

The diagnosis of heart failure with preserved ejection fraction (HFpEF) requires: (1) symptoms/signs of heart failure; (2) preserved LVEF (>= 50%); and (3) objective evidence of elevated LV filling pressures and diastolic dysfunction. Under the HFA-PEFF score, major criteria include average E/e' >= 15, septal e' < 7 cm/s, LAVI > 34 mL/m2, and NT-proBNP > 220 pg/mL in sinus rhythm. All these criteria are fulfilled.

Question 21Heart failure, cardiomyopathy and pericardial disease

A 22-year-old competitive soccer player is evaluated for exertional lightheadedness. Physical examination reveals a harsh crescendo-decrescendo systolic murmur heard best along the left sternal border with no radiation to the carotid arteries. The murmur intensifies markedly during the strain phase of the Valsalva maneuver and decreases in intensity when the patient moves from standing to squatting. What condition does this murmur dynamic classically identify?

  1. Ventricular septal defect
  2. Valvular aortic stenosis
  3. Hypertrophic obstructive cardiomyopathy (HOCM) Correct answer.
  4. Mitral valve regurgitation due to papillary rupture

Explanation

The systolic murmur of hypertrophic obstructive cardiomyopathy (HOCM) is caused by dynamic left ventricular outflow tract (LVOT) obstruction and systolic anterior motion (SAM) of the mitral valve. Maneuvers that reduce LV preload or chamber size (such as the strain phase of the Valsalva maneuver or standing) bring the anterior mitral leaflet closer to the hypertrophied septum, worsening obstruction and intensifying the murmur. Conversely, squatting increases preload and afterload, enlarging the LV chamber and decreasing murmur intensity.

Question 22Heart failure, cardiomyopathy and pericardial disease

Which of the following medications is strictly contraindicated in a symptomatic patient with hypertrophic cardiomyopathy and a resting left ventricular outflow tract (LVOT) gradient of 65 mmHg?

  1. Oral disopyramide
  2. Oral metoprolol succinate
  3. Oral verapamil
  4. Sublingual nitroglycerin Correct answer.

Explanation

In hypertrophic obstructive cardiomyopathy (HOCM), vasodilators (such as nitrates and dihydropyridine calcium channel blockers) reduce ventricular preload and systemic vascular resistance, decreasing left ventricular cavity size. This exacerbates systolic anterior motion (SAM) of the mitral valve, worsens LVOT obstruction, and can precipitate profound syncope or hemodynamic collapse. Negative inotropes (beta-blockers, verapamil, disopyramide) are the preferred medical therapies.

Question 23Heart failure, cardiomyopathy and pericardial disease

A 28-year-old male with confirmed sarcomeric hypertrophic cardiomyopathy undergoes risk stratification for sudden cardiac death (SCD). Which clinical finding represents a recognized major risk factor supporting the placement of a primary prevention implantable cardioverter-defibrillator (ICD)?

  1. Maximum left ventricular wall thickness >= 30 mm Correct answer.
  2. Presence of sinus arrhythmia on 24-hour Holter monitoring
  3. Resting left ventricular ejection fraction of 68%
  4. Mild unicuspid aortic valve sclerosis without stenosis

Explanation

Major conventional risk factors for sudden cardiac death in hypertrophic cardiomyopathy that support primary prevention ICD implantation include: massive LV hypertrophy (maximal wall thickness >= 30 mm), unexplained recent syncope, family history of premature sudden cardiac death in a first-degree relative, nonsustained ventricular tachycardia (NSVT) on ambulatory monitoring, LV apical aneurysm, and end-stage systolic dysfunction (LVEF < 50%).

Question 24Heart failure, cardiomyopathy and pericardial disease

During cardiac catheterization of a patient with suspected constrictive pericarditis versus restrictive cardiomyopathy, hemodynamic tracings are recorded. Which hemodynamic finding decisively favors constrictive pericarditis over restrictive cardiomyopathy?

  1. Pulmonary artery systolic pressure markedly elevated above 65 mmHg
  2. Marked respiratory ventricular interdependence, demonstrated by discordant changes in right and left ventricular peak systolic pressures during respiration Correct answer.
  3. Left ventricular end-diastolic pressure exceeding right ventricular end-diastolic pressure by more than 10 mmHg
  4. Complete absence of early rapid ventricular filling ('dip and plateau' sign)

Explanation

Because the rigid pericardium insulates the cardiac chambers from intrathoracic pressure changes while total cardiac volume is fixed, constrictive pericarditis exhibits enhanced ventricular interdependence. On catheterization, inspiration increases RV systolic pressure while LV systolic pressure simultaneously falls (discordance). In restrictive cardiomyopathy, ventricular pressures vary concordantly with respiration. Furthermore, restrictive cardiomyopathy typically produces high PA pressures (>50 mmHg) and an LVEDP-RVEDP difference > 5 mmHg.

Question 25Heart failure, cardiomyopathy and pericardial disease

A 48-year-old male with chronic heavy alcohol consumption (consuming > 100 g of ethanol daily for 15 years) presents with new-onset heart failure symptoms. Echocardiogram reveals bi-ventricular dilatation, generalized hypokinesis, and a left ventricular ejection fraction of 24%. Coronary angiography shows completely normal epicardial coronary vessels. Which of the following statements regarding alcoholic cardiomyopathy is correct?

  1. Standard heart failure guideline-directed medical therapy is strictly contraindicated
  2. Alcohol has direct inotropic stimulatory effects that cause hypertrophic outflow obstruction
  3. Cardiac transplantation is the mandatory first-line therapy within 30 days of initial diagnosis
  4. Complete abstinence from alcohol can lead to significant functional recovery and reverse left ventricular remodeling Correct answer.

Explanation

Alcoholic cardiomyopathy is a secondary form of dilated cardiomyopathy caused by direct toxic effects of ethanol and its metabolites (acetaldehyde) on cardiomyocyte protein synthesis, excitation-contraction coupling, and mitochondrial function. Strict and sustained cessation of alcohol intake leads to substantial improvement or complete normalization of left ventricular ejection fraction and dimensions in a significant proportion of patients when combined with standard GDMT.

Question 26Heart failure, cardiomyopathy and pericardial disease

A Cuban physician returning from an international medical collaboration mission in South America evaluates a 52-year-old male with chronic Trypanosoma cruzi infection. A 12-lead ECG is obtained. Which electrocardiographic abnormalities represent the classic, most frequent conduction disturbance seen in chronic Chagas cardiomyopathy?

  1. Isolated Mobitz Type I second-degree AV block
  2. Right bundle branch block (RBBB) combined with left anterior fascicular block (LAFB) Correct answer.
  3. Persistent short PR interval with delta waves
  4. Diffuse concave ST-segment elevations with PR depressions

Explanation

Chronic Chagasic cardiomyopathy has a unique predilection for destroying the conduction system, particularly the right bundle branch and the anterior division of the left bundle. The combination of complete right bundle branch block (RBBB) and left anterior fascicular block (LAFB) is the classical ECG hallmark of Chagas heart disease. Other frequent findings include apical LV aneurysms, ventricular tachyarrhythmias, and high-grade AV block.

Question 27Heart failure, cardiomyopathy and pericardial disease

A 24-year-old male develops acute retrosternal chest pain and dyspnea 10 days following a viral upper respiratory infection. Troponin I is elevated at 4.2 ng/mL and coronary angiography is normal. Cardiac magnetic resonance imaging (CMR) is performed. According to the updated Lake Louise Criteria, which combination of CMR tissue characterization findings confirms the diagnosis of acute myocarditis?

  1. Diffuse concentric transmural subendocardial fibrosis confined to the subendocardium
  2. Isolated diffuse pericardial calcification without myocardial signal abnormality
  3. Evidence of myocardial edema (T2 mapping or T2-weighted hyperintensity) combined with evidence of myocardial injury/necrosis (T1 mapping, extracellular volume elevation, or late gadolinium enhancement) Correct answer.
  4. Absence of all myocardial signal alterations on T1 and T2 sequences

Explanation

The updated Lake Louise Criteria for cardiac MRI diagnosis of acute myocarditis require at least one T2-based criterion (demonstrating myocardial edema via increased T2 relaxation times or T2-weighted regional hyperintensity) PLUS at least one T1-based criterion (demonstrating associated myocardial injury/necrosis via increased native T1 times, expanded extracellular volume [ECV], or non-ischemic late gadolinium enhancement [LGE] in a subepicardial or mid-wall pattern).

Question 28Heart failure, cardiomyopathy and pericardial disease

A 70-year-old male admitted with acute decompensated heart failure develops diuretic resistance, producing less than 500 mL of urine per day despite an escalating intravenous furosemide regimen of 120 mg twice daily. His blood pressure is 118/74 mmHg and serum potassium is 4.6 mEq/L. Which pharmacological strategy ('sequential nephron blockade') is recommended to overcome this loop diuretic resistance?

  1. Immediately discontinue all diuretics and initiate fluid boluses
  2. Add a thiazide or thiazide-like diuretic (such as metolazone or hydrochlorothiazide) or intravenous acetazolamide Correct answer.
  3. Switch to oral bumetanide at subtherapeutic microdoses
  4. Administer high-dose vasopressin intravenously

Explanation

Chronic or high-dose loop diuretic therapy induces compensatory hypertrophy of distal convoluted tubule epithelial cells, leading to avid downstream sodium reabsorption (the 'braking phenomenon'). Sequential nephron blockade overcomes this by combining a loop diuretic (acting at the thick ascending limb of Henle) with a distal tubule thiazide-like diuretic (metolazone or chlorothiazide) or a proximal tubule inhibitor (acetazolamide, as supported by the ADVOR trial).

Question 29Heart failure, cardiomyopathy and pericardial disease

In patients with chronic heart failure (HFrEF or HFmrEF), iron deficiency is a powerful independent predictor of exercise intolerance, hospitalizations, and mortality. How is iron deficiency defined in this population according to clinical practice guidelines?

  1. Elevated serum iron > 200 mcg/dL with total iron binding capacity < 150 mcg/dL
  2. Serum ferritin < 10 ng/mL with microcytic hypochromic anemia (Hb < 8 g/dL)
  3. Serum ferritin < 100 ng/mL, or serum ferritin 100 to 299 ng/mL with a transferrin saturation (TSAT) < 20% Correct answer.
  4. Transferrin saturation > 50% regardless of ferritin concentration

Explanation

Because heart failure is a chronic inflammatory state with elevated hepcidin levels, standard population cutoffs do not apply. Clinical guidelines define iron deficiency in heart failure as: serum ferritin < 100 ng/mL (absolute iron deficiency), OR serum ferritin 100 to 299 ng/mL with a transferrin saturation (TSAT) < 20% (functional iron deficiency). Intravenous iron (such as ferric carboxymaltose or ferric derisomaltose) improves functional status and reduces hospitalizations regardless of baseline hemoglobin.

Question 30Heart failure, cardiomyopathy and pericardial disease

A 56-year-old male with end-stage ischemic cardiomyopathy in refractory INTERMACS Profile 2 cardiogenic shock requires mechanical circulatory support. What hemodynamic advantage does a continuous-flow left ventricular assist device (LVAD) provide when compared to venoarterial extracorporeal membrane oxygenation (VA-ECMO)?

  1. The LVAD does not require surgical sternotomy and can be inserted via peripheral venous cannulation in the polyclinic
  2. The LVAD provides immediate total biventricular and pulmonary gas exchange support without requiring a functional right ventricle
  3. VA-ECMO reduces systemic vascular resistance and eliminates the risk of arterial thromboembolism
  4. The LVAD directly unloads the left ventricle, decreasing LV end-diastolic pressure and wall stress, whereas VA-ECMO increases LV afterload and can worsen pulmonary edema unless an unloading strategy is added Correct answer.

Explanation

A continuous-flow LVAD aspirates blood from the LV apex and ejects it into the ascending aorta, directly decompressing and unloading the left ventricle, which dramatically reduces LV end-diastolic pressure, volume, and wall stress. In contrast, peripheral VA-ECMO returns pressurized blood retrograde into the femoral and ascending aorta, increasing LV afterload, which can cause severe LV distension, stasis, and secondary pulmonary edema unless active venting (such as an Impella or septostomy) is utilized.

Question 31Rhythm analysis, conduction disease and device reasoning

A 72-year-old female with permanent atrial fibrillation has a history of hypertension, type 2 diabetes mellitus, and a prior ischemic stroke 2 years ago. Her blood pressure is 132/78 mmHg and she has no history of heart failure or vascular disease. What is her calculated CHA2DS2-VASc score, and what is the guideline recommendation for thromboembolic stroke prevention?

  1. CHA2DS2-VASc score of 6; oral anticoagulation is strongly indicated (Class I) Correct answer.
  2. CHA2DS2-VASc score of 2; oral anticoagulation is optional based on patient preference
  3. CHA2DS2-VASc score of 1; aspirin 81 mg daily monotherapy is sufficient
  4. CHA2DS2-VASc score of 0; no antithrombotic therapy is indicated

Explanation

Under the explicitly named traditional CHA2DS2-VASc system, age 72 contributes 1, hypertension 1, diabetes 1, prior ischemic stroke 2 and female sex category 1, totaling 6. This is a high-risk profile supporting anticoagulation when clinically appropriate. Do not confuse this total with CHA2DS2-VA, which excludes the sex-category component.

Question 32Rhythm analysis, conduction disease and device reasoning

A 58-year-old male with symptomatic non-valvular atrial fibrillation lasting for at least 3 months is scheduled for elective electrical cardioversion. Transesophageal echocardiography (TEE) is not immediately available. According to clinical guidelines, what is the mandatory antithrombotic protocol prior to and following elective cardioversion?

  1. Intravenous heparin for 2 hours before cardioversion, with discontinuation of all anticoagulation upon restoration of sinus rhythm
  2. At least 3 weeks of continuous therapeutic oral anticoagulation before cardioversion, followed by at least 4 weeks of therapeutic anticoagulation afterward Correct answer.
  3. Aspirin 325 mg daily for 7 days before and after cardioversion
  4. No anticoagulation is required if the patient is under 60 years of age

Explanation

In patients with atrial fibrillation of >= 48 hours duration (or unknown duration) undergoing elective cardioversion without prior transesophageal echocardiogram (TEE) to exclude left atrial appendage thrombus, therapeutic oral anticoagulation is mandatory for at least 3 weeks prior to cardioversion. Therapeutic anticoagulation must be continued for at least 4 weeks after cardioversion due to transient atrial stunning that predisposes to thromboembolism.

Question 33Rhythm analysis, conduction disease and device reasoning

A 70-year-old male with acute decompensated heart failure and an LVEF of 25% presents to the emergency department in atrial fibrillation with a rapid ventricular response of 148 bpm. His blood pressure is 105/70 mmHg. Which intravenous rate-controlling agent is safest and most appropriate in this patient?

  1. Intravenous high-dose propranolol bolus
  2. Intravenous diltiazem bolus and infusion
  3. Intravenous verapamil bolus
  4. Intravenous digoxin or intravenous amiodarone Correct answer.

Explanation

In patients with acute decompensated heart failure and severely reduced ejection fraction (HFrEF), non-dihydropyridine calcium channel blockers (diltiazem, verapamil) and intravenous beta-blockers are contraindicated or hazardous because their negative inotropic effects can precipitate cardiogenic shock. Intravenous digoxin or intravenous amiodarone are the recommended agents of choice for acute rate control in decompensated HFrEF.

Question 34Rhythm analysis, conduction disease and device reasoning

A 14-year-old boy suffers syncope while participating in a competitive swimming meet. His baseline 12-lead ECG shows a prolonged QTc interval of 510 ms with broad-based, notched T waves. Genetic testing identifies a pathogenic loss-of-function mutation in the KCNQ1 gene encoding the slow delayed rectifier potassium current (IKs). What is the specific genetic diagnosis and the first-line long-term medical therapy?

  1. Brugada syndrome Type 1; oral quinidine therapy
  2. Congenital Long QT Syndrome Type 1 (LQT1); non-selective beta-blockers (nadolol or propranolol) Correct answer.
  3. Catecholaminergic polymorphic ventricular tachycardia; flecainide monotherapy
  4. Short QT syndrome; oral digitalis glycosides

Explanation

Mutations in KCNQ1 impair the IKs potassium channel, causing Long QT Syndrome Type 1 (LQT1). LQT1 accounts for approximately 40-50% of congenital LQTS cases and is characteristically triggered by adrenergic surges, particularly swimming and vigorous exertion. Non-selective beta-blockers (such as nadolol or propranolol) are the cornerstone of first-line therapy, achieving dramatic reductions in cardiac events and sudden death.

Question 35Rhythm analysis, conduction disease and device reasoning

A 26-year-old competitive athlete presents with palpitations and non-sustained ventricular tachycardia of left bundle branch block (LBBB) morphology with superior axis. A 12-lead ECG demonstrates T-wave inversion in leads V1 through V3 and a distinct terminal notch at the end of the QRS complex in lead V1 (epsilon wave). Cardiac MRI reveals localized right ventricular microaneurysms and fibrofatty infiltration of the RV free wall. What is the diagnosis?

  1. Ostium secundum atrial septal defect with normal RV tissue
  2. Coronary slow-flow phenomenon
  3. Acute pulmonary embolism with McGinn-White syndrome
  4. Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) Correct answer.

Explanation

Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is a genetic desmosomal heart disease characterized by progressive fibrofatty replacement of the right ventricular myocardium. Classic diagnostic criteria (revised Task Force criteria) include: epsilon waves (terminal notch at the end of QRS in V1-V2 due to delayed right ventricular activation), T-wave inversions in right precordial leads (V1-V3), VT of LBBB morphology, and structural RV wall motion abnormalities or fibrofatty replacement on MRI.

Question 36Rhythm analysis, conduction disease and device reasoning

A 78-year-old male presents with recurrent presyncope. His ECG displays a regular atrial rate of 84 bpm and an independent, regular ventricular escape rate of 34 bpm with wide QRS complexes. There is no relationship between the P waves and the QRS complexes (complete AV dissociation). Physical examination reveals intermittent prominent 'cannon a waves' in the jugular venous pulse. What is the definitive treatment?

  1. Permanent dual-chamber pacemaker implantation Correct answer.
  2. Oral atropine 1 mg three times daily
  3. Intravenous verapamil infusion
  4. External synchronized cardioversion

Explanation

Complete (third-degree) atrioventricular block is characterized by complete failure of atrial impulses to conduct to the ventricles, resulting in independent atrial and ventricular rhythms (AV dissociation). Cannon 'a' waves occur intermittently when the right atrium contracts against a closed tricuspid valve during ventricular systole. Third-degree AV block in an older adult represents permanent infranodal conduction system disease with a Class I indication for permanent pacemaker implantation.

Question 37Rhythm analysis, conduction disease and device reasoning

Which of the following electrocardiographic characteristics distinguishes second-degree Mobitz Type II atrioventricular block from second-degree Mobitz Type I (Wenckebach) AV block?

  1. Mobitz Type II always occurs within the proximal AV node and responds promptly to atropine
  2. Mobitz Type II exhibits constant, unchanging PR intervals in the conducted beats preceding a suddenly dropped P wave, whereas Mobitz Type I exhibits progressive PR prolongation prior to the dropped beat Correct answer.
  3. Mobitz Type I is always caused by irreversible trifascicular structural disease requiring urgent transvenous pacing
  4. Mobitz Type II exhibits progressive shortening of the RR intervals preceding a non-conducted beat

Explanation

In Mobitz Type I (Wenckebach) AV block, decremental conduction in the AV node produces progressive PR prolongation until a P wave fails to conduct; the block is typically intra-nodal and benign. In contrast, Mobitz Type II block is localized infranodally (within the bundle of His or bundle branches), characterized by fixed, unchanging PR intervals prior to an unexpectedly blocked P wave. Mobitz Type II carries a high risk of progressing to complete heart block and sudden asystole, representing a Class I indication for permanent pacing.

Question 38Rhythm analysis, conduction disease and device reasoning

A 74-year-old female presents with alternating episodes of marked sinus bradycardia with sinus pauses lasting up to 3.8 seconds, followed by paroxysms of rapid atrial fibrillation with palpitations and presyncope (tachycardia-bradycardia syndrome). Her cardiologist wishes to prescribe an antiarrhythmic agent to suppress the tachyarrhythmias. What intervention must be accomplished prior to safely initiating medical therapy?

  1. Biventricular defibrillator vest for 12 months
  2. Radiofrequency ablation of the left main coronary artery
  3. Permanent pacemaker implantation to safeguard against profound bradycardia and asystole Correct answer.
  4. Surgical bilateral carotid endarterectomy

Explanation

Tachycardia-bradycardia syndrome is a manifestation of sick sinus syndrome (sinus node dysfunction). Attempting to manage the paroxysmal tachyarrhythmias pharmacologically with beta-blockers, calcium channel blockers, digoxin, or antiarrhythmics without prior pacemaker implantation will worsen sinus pauses and precipitate prolonged sinus arrest or asystole. Permanent pacemaker implantation allows safe subsequent titration of rate- or rhythm-controlling drugs.

Question 39Rhythm analysis, conduction disease and device reasoning

A 54-year-old male presents with regular palpitations. The 12-lead ECG reveals a classic 'sawtooth' baseline pattern with inverted flutter waves in leads II, III, and aVF, upright flutter waves in lead V1, and an atrial rate of 300 bpm with 2:1 AV conduction resulting in a ventricular rate of 150 bpm. What is the definitive curative electrophysiological catheter ablation target for this typical atrial flutter?

  1. The right upper pulmonary vein antrum
  2. The cavotricuspid isthmus (CTI) located between the inferior vena cava and the tricuspid valve annulus Correct answer.
  3. The left ventricular apex
  4. The coronary sinus ostium roof exclusively

Explanation

Typical counterclockwise atrial flutter is a macroreentrant circuit confined to the right atrium that circulates around the tricuspid valve annulus, traversing the cavotricuspid isthmus (CTI)-the narrow band of myocardium bounded anteriorly by the tricuspid valve annulus and posteriorly by the Eustachian ridge and inferior vena cava. Radiofrequency catheter ablation creating a bidirectional conduction block across the CTI cures typical atrial flutter with a success rate exceeding 95%.

Question 40Valves, endocarditis and congenital circulation

A 42-year-old woman with severe rheumatic mitral stenosis (mitral valve area 1.0 cm2) is evaluated for percutaneous balloon mitral valvuloplasty (PBMV). An echocardiographic score (Wilkins score) is calculated. What four morphological components are evaluated in the Wilkins score, and what total score cutoff typically predicts a favorable procedure outcome?

  1. Leaflet mobility, leaflet thickening, subvalvular thickening, and valvular calcification; a total score <= 8 predicts favorable procedural outcomes Correct answer.
  2. Left atrial volume, tricuspid regurgitation velocity, aortic root diameter, and pericardial thickness; score <= 12
  3. Ejection fraction, coronary flow reserve, carotid intima-media thickness, and pulmonary pressure; score <= 6
  4. Chordal length, mitral annular calcification, aortic regurgitation volume, and stroke volume index; score <= 4

Explanation

The Wilkins echocardiographic score evaluates four distinct anatomical components of the rheumatic mitral valve: (1) Leaflet mobility; (2) Leaflet thickening; (3) Subvalvular thickening; and (4) Valvular calcification. Each component is graded from 1 to 4, yielding a total score from 4 to 16. A total Wilkins score <= 8 with no more than mild commissural calcification and absence of left atrial thrombus or moderate-to-severe mitral regurgitation predicts successful balloon commissurotomy with low complication rates.

Question 41Valves, endocarditis and congenital circulation

Which of the following echocardiographic findings is an absolute contraindication to performing percutaneous balloon mitral valvuloplasty (PBMV) in a patient with severe symptomatic mitral stenosis?

  1. Atrial fibrillation with controlled ventricular response
  2. Presence of a documented free-floating or organized thrombus in the left atrium or left atrial appendage Correct answer.
  3. Resting pulmonary artery systolic pressure of 55 mmHg
  4. Presence of an opening snap heard on cardiac auscultation

Explanation

Absolute contraindications to percutaneous balloon mitral valvuloplasty (PBMV) include: (1) Presence of a thrombus in the left atrium or left atrial appendage (due to the unacceptable risk of catastrophic systemic embolic stroke during catheter manipulation or transseptal puncture); and (2) Moderate or severe mitral regurgitation (which would be exacerbated into life-threatening regurgitation). Other contraindications include severe bicommissural calcification.

Question 42Valves, endocarditis and congenital circulation

A 76-year-old male presents with exertional angina and syncope. Transthoracic echocardiogram reveals calcific aortic valve disease. Which set of hemodynamic echocardiographic parameters meets the standard criteria for severe high-gradient aortic stenosis?

  1. Aortic valve area > 2.0 cm2 with an indexed valve area > 1.1 cm2/m2
  2. Aortic valve area > 1.5 cm2, mean gradient < 20 mmHg, and peak velocity < 2.5 m/s
  3. Aortic valve area (AVA) <= 1.0 cm2, mean transvalvular gradient >= 40 mmHg, and peak aortic jet velocity >= 4.0 m/s Correct answer.
  4. Aortic valve area between 1.2 and 1.5 cm2, mean gradient 25 mmHg, and peak velocity 3.0 m/s

Explanation

Severe high-gradient aortic stenosis is defined by international and Cuban valvular guidelines by all three of the following echocardiographic parameters (in the setting of normal cardiac output): (1) Aortic valve area (AVA) <= 1.0 cm2 (or indexed AVA <= 0.6 cm2/m2); (2) Mean transvalvular pressure gradient >= 40 mmHg; and (3) Peak aortic jet velocity >= 4.0 m/s.

Question 43Valves, endocarditis and congenital circulation

A 72-year-old male with chronic heart failure has an LVEF of 28%, a calculated aortic valve area of 0.8 cm2, but a resting mean transvalvular aortic gradient of only 26 mmHg (classical low-flow, low-gradient aortic stenosis). Low-dose dobutamine stress echocardiography is performed. During dobutamine infusion, his stroke volume increases by 32%, the mean gradient increases to 44 mmHg, while the aortic valve area remains 0.85 cm2. How are these findings interpreted?

  1. Absence of contractile reserve; the patient has a prohibitive operative mortality and must receive hospice care
  2. Pseudo-severe aortic stenosis; the patient has primarily cardiomyopathy and valve intervention should be withheld
  3. Normal aortic valve hemodynamics with no intrinsic valvular pathology
  4. True severe aortic stenosis with documented left ventricular contractile flow reserve; surgical or transcatheter aortic valve replacement is indicated Correct answer.

Explanation

In classical low-flow, low-gradient aortic stenosis (reduced LVEF < 50%, AVA <= 1.0 cm2, mean gradient < 40 mmHg), low-dose dobutamine stress echocardiography is required. An increase in stroke volume >= 20% confirms the presence of contractile (flow) reserve. True severe AS is diagnosed when the mean gradient increases to >= 40 mmHg while the AVA remains <= 1.0 cm2, confirming that the valve is rigidly fixed. These patients derive substantial survival benefit from aortic valve replacement.

Question 44Valves, endocarditis and congenital circulation

An 82-year-old woman with severe symptomatic calcific aortic stenosis (mean gradient 48 mmHg, AVA 0.7 cm2) is evaluated for aortic valve intervention by the multidisciplinary Heart Team. She has severe porcelain aorta on CT, an STS operative mortality risk score of 9.2%, and favorable transfemoral vascular anatomy. What is the preferred intervention?

  1. Transcatheter aortic valve implantation (TAVI) via transfemoral access Correct answer.
  2. Open surgical aortic valve replacement (SAVR) with deep hypothermic circulatory arrest
  3. Percutaneous balloon aortic valvuloplasty as definitive lifelong therapy
  4. Medical therapy with high-dose statins alone

Explanation

In older patients (>= 75-80 years) or those with high or prohibitive surgical risk (STS score > 8%) or anatomical contraindications to sternotomy/cross-clamping (such as a porcelain aorta), transfemoral transcatheter aortic valve implantation (TAVI) is strongly favored over surgical AVR based on randomized trials (PARTNER, CoreValve) showing lower mortality, reduced stroke, and faster recovery.

Question 45Valves, endocarditis and congenital circulation

A 48-year-old asymptomatic male with severe chronic primary aortic regurgitation is monitored in the outpatient cardiology clinic. Transthoracic echocardiography reveals an LVEF of 46% and a left ventricular end-systolic diameter (LVESD) of 52 mm (indexed LVESD 26 mm/m2). What is the appropriate clinical recommendation according to valvular heart disease guidelines?

  1. Continued watchful waiting with repeat echocardiogram scheduled in 2 years
  2. Referral for surgical aortic valve replacement or repair, because systolic dysfunction (LVEF <= 50% or LVESD > 50 mm) triggers a Class I surgical indication even in asymptomatic patients Correct answer.
  3. Initiation of high-dose digoxin monotherapy with no surgical intervention
  4. Immediate urgent intra-aortic balloon pump counterpulsation

Explanation

In chronic severe aortic regurgitation, long-standing volume overload produces eccentric left ventricular hypertrophy and dilation. Even in completely asymptomatic patients, surgical aortic valve intervention is recommended (Class I) when signs of early LV decompensation emerge: specifically, resting LVEF <= 50%, or resting LV end-systolic diameter (LVESD) > 50 mm (or > 25 mm/m2). Delaying surgery beyond these parameters leads to irreversible myocardial fibrosis and poor postoperative survival.

Question 46Valves, endocarditis and congenital circulation

A 36-year-old male presents with acute severe aortic regurgitation following infective endocarditis. He is in severe pulmonary edema and cardiogenic shock with a blood pressure of 85/60 mmHg. Which clinical device or intervention is STRICTLY CONTRAINDICATED in the stabilization of acute severe aortic regurgitation?

  1. Urgent emergency cardiac surgery
  2. Intravenous nitroprusside infusion
  3. Intra-aortic balloon pump (IABP) counterpulsation Correct answer.
  4. Intravenous dobutamine infusion

Explanation

The intra-aortic balloon pump (IABP) is strictly contraindicated in moderate or severe aortic regurgitation. The IABP inflates during diastole to augment coronary perfusion pressure; in the setting of an incompetent aortic valve, diastolic balloon inflation forces massive volumes of pressurized aortic blood retrograde across the valve directly into the non-compliant left ventricle, precipitating catastrophic LV distension, acute pulmonary edema, and electromechanical dissociation.

Question 47Valves, endocarditis and congenital circulation

A 56-year-old asymptomatic male with severe degenerative (primary) mitral regurgitation due to posterior leaflet prolapse is evaluated. Transthoracic echocardiography demonstrates an effective regurgitant orifice area (EROA) of 0.48 cm2, regurgitant volume of 68 mL, left ventricular ejection fraction of 57%, and a left ventricular end-systolic diameter (LVESD) of 42 mm. What is the most appropriate management according to clinical guidelines?

  1. Transcatheter edge-to-edge repair (TEER) as the mandatory first choice over surgical repair
  2. Reassurance that surgery is only indicated if LVEF drops below 30%
  3. Prescription of high-dose ACE inhibitors with routine follow-up in 3 years
  4. Referral for surgical mitral valve repair at a heart valve center of excellence Correct answer.

Explanation

In primary (degenerative) mitral regurgitation, surgical intervention-with valve repair strongly preferred over replacement-is indicated in asymptomatic severe MR when there is evidence of early LV systolic dysfunction, defined as LVEF <= 60% and/or LV end-systolic diameter (LVESD) >= 40 mm. Because the normal ejection fraction in significant MR is supranormal (>65-70%) due to low-impedance regurgitation into the left atrium, an LVEF of 57% already reflects significant occult systolic impairment.

Question 48Valves, endocarditis and congenital circulation

According to the Modified Duke Criteria for the diagnosis of infective endocarditis, which combination fulfills the requirements for a 'Definite' clinical diagnosis?

  1. Two major criteria (e.g. typical blood culture positive and echocardiographic demonstration of a mobile oscillating intracardiac vegetation) Correct answer.
  2. One major criterion and one minor criterion
  3. Three minor criteria alone
  4. Fever and elevated ESR in the absence of bacteremia or echocardiographic findings

Explanation

Under the Modified Duke Criteria, a 'Definite' clinical diagnosis of infective endocarditis is established by: (1) Two major criteria; OR (2) One major criterion and three minor criteria; OR (3) Five minor criteria. Major criteria comprise persistently positive blood cultures with typical microorganisms and imaging evidence of endocardial involvement (oscillating vegetation, abscess, or new partial dehiscence of a prosthetic valve).

Question 49Valves, endocarditis and congenital circulation

A 45-year-old male with native aortic valve Staphylococcus aureus endocarditis has received 7 days of appropriate intravenous antibiotic therapy. Despite this, he remains febrile, blood cultures at day 6 remain persistently positive, and a repeat transesophageal echocardiogram demonstrates an aortic root abscess with a new 14 mm highly mobile vegetation on the non-coronary cusp. What is the immediate indicated management?

  1. Switching to oral cephalexin and outpatient discharge
  2. Urgent surgical aortic valve replacement and aortic root debridement/reconstruction Correct answer.
  3. Adding oral aspirin and observation for an additional 4 weeks
  4. Performing percutaneous catheter-directed mechanical suction of the vegetation

Explanation

Urgent/early surgical intervention in active infective endocarditis is indicated for three primary categories of complications: (1) Heart failure due to acute severe valvular regurgitation; (2) Uncontrolled infection (persistent positive blood cultures or persistent fever >7-10 days despite targeted antibiotics, enlarging abscess, pseudoaneurysm, or fungal etiology); and (3) Prevention of systemic embolism in patients with large mobile vegetations (>10 mm), especially with Staphylococcal infection.

Question 50Valves, endocarditis and congenital circulation

A 50-year-old male with a mechanical bileaflet mitral valve replacement asks his cardiologist whether he can switch his daily warfarin to a direct oral anticoagulant (DOAC, such as dabigatran, apixaban, or rivaroxaban) to avoid routine INR blood testing. What is the correct clinical recommendation based on the RE-ALIGN trial and valvular guidelines?

  1. DOACs may be substituted if combined with high-dose aspirin
  2. DOACs are fully approved and preferred over warfarin for all mechanical valves
  3. Warfarin may be safely stopped without substituting any anticoagulant
  4. DOACs are strictly contraindicated in patients with mechanical heart valves due to significantly increased rates of valve thrombosis and major bleeding compared to warfarin Correct answer.

Explanation

The randomized clinical trial RE-ALIGN evaluated the direct thrombin inhibitor dabigatran versus warfarin in patients with mechanical heart valves and was terminated early due to an excess of both thromboembolic events (valve thrombosis and stroke) and major bleeding in the dabigatran arm. Direct oral anticoagulants (DOACs) are strictly contraindicated in patients with mechanical prosthetic heart valves; vitamin K antagonists (warfarin) remain the only approved oral anticoagulant.