Iran Specialty Board - Cardiology cheat sheet

High-sensitivity troponin is preferred; a rise/fall pattern with at least one value above the 99th percentile URL defines acute myocardial injury, and acute MI requires evidence of ischemia (symptoms, ECG changes, imaging, or angiographic thrombus).

Type 1 MI = atherothrombotic plaque rupture/erosion; type 2 MI = oxygen supply-demand mismatch without acute plaque thrombosis; both require troponin elevation with ischemia.

STEMI criteria: new ST elevation in 2 contiguous leads ≥1 mm (≥2 mm in men ≥40 in V2-V3; ≥2.5 mm in men <40; ≥1.5 mm in women), or new LBBB with ischemic symptoms; posterior MI suggested by V1-V3 ST depression with tall R waves.

Primary PCI is preferred if achievable within 120 minutes of first medical contact; otherwise fibrinolysis within 12 hours of symptom onset (door-to-needle ≤30 min) followed by transfer for angiography.

Dual antiplatelet therapy (aspirin plus a P2Y12 inhibitor) for 12 months after ACS is standard; prasugrel is contraindicated after stroke/TIA and avoided in patients ≥75 years or <60 kg without dose adjustment.

TIMI risk score components: age ≥65, ≥3 CAD risk factors, known CAD ≥50% stenosis, ASA use in past 7 days, severe angina (≥2 episodes in 24 h), ST deviation ≥0.5 mm, and elevated cardiac markers.

Culprit-vessel identification in NSTEMI uses ECG, echocardiography, and angiography; routine early invasive strategy (<24 h) is favored in high-risk features (GRACE >140, dynamic ST changes, hemodynamic instability).

HFrEF is defined by LVEF ≤40%, HFmrEF by 41-49%, and HFpEF by ≥50%; HFpEF diagnosis requires symptoms plus evidence of elevated filling pressures (echo E/e', natriuretic peptides, or invasive hemodynamics).

Four pillars of HFrEF therapy with mortality benefit: ARNI/ACEi/ARB, beta-blocker (bisoprolol, carvedilol, metoprolol succinate, nebivolol), MRA, and SGLT2 inhibitor; all four are recommended early and titrated to target.

Sacubitril/valsartan is contraindicated with prior ACEi within 36 hours (angioedema risk) and in pregnancy; it is preferred over ACEi in eligible HFrEF patients.

Ivabradine is indicated for HFrEF with LVEF ≤35%, sinus rhythm ≥70 bpm, and persistent symptoms despite maximally tolerated beta-blocker; it is not used in AF.

Dilated cardiomyopathy: LV dilation with reduced EF; common causes include ischemia, alcohol, viral myocarditis, and familial/genetic mutations (up to 30-40% familial).

Hypertrophic cardiomyopathy: asymmetric septal hypertrophy with LVOT obstruction; avoid vasodilators and diuretics that worsen preload; beta-blockers or verapamil first-line; septal reduction for refractory symptoms.

Cardiac amyloidosis: low-voltage ECG despite thick ventricles, apical sparing on strain imaging, and bone-tracer uptake; AL amyloid requires urgent hematology referral for chemotherapy.

Aortic stenosis severity: peak velocity ≥4 m/s, mean gradient ≥40 mmHg, or aortic valve area ≤1.0 cm² (≤0.6 cm²/cm² indexed); low-flow low-gradient AS requires dobutamine stress echo or calcium scoring.

Severe symptomatic AS is a class I indication for AVR; TAVR is preferred in patients at high or prohibitive surgical risk and increasingly in intermediate/low risk based on anatomy and age.

Acute severe aortic regurgitation (e.g., endocarditis, dissection) presents with pulmonary edema and cardiogenic shock; surgery is urgent and intra-aortic balloon pump is contraindicated.

Mitral stenosis is typically rheumatic; severity by valve area (<1.5 cm² moderate, <1.0 cm² severe) and mean gradient; percutaneous balloon commissurotomy is preferred when valve morphology is suitable and there is no left atrial thrombus or significant MR.

Primary mitral regurgitation: surgery for symptomatic severe MR or asymptomatic severe MR with LVEF ≤60% or LVESD ≥40 mm; secondary MR is treated with guideline-directed medical therapy first, then transcatheter edge-to-edge repair.

Prosthetic valve thrombosis: suspect with new dyspnea or embolic event; TEE is diagnostic; treatment is fibrinolysis or surgery depending on thrombus burden and hemodynamic stability.

Endocarditis surgical indications: heart failure from valve dysfunction, uncontrolled infection (abscess, persistent bacteremia), and prevention of embolism (large vegetations >10 mm, recurrent emboli).

Supraventricular tachycardia: vagal maneuvers then adenosine 6 mg IV (then 12 mg); avoid adenosine in pre-excited AF or severe asthma.

Atrial fibrillation anticoagulation: CHA2DS2-VASc score ≥2 in men or ≥3 in women indicates anticoagulation; DOACs are preferred over warfarin except in mechanical valves or moderate-severe mitral stenosis.

Ventricular tachycardia vs SVT with aberrancy: VT is favored by AV dissociation, capture/fusion beats, extreme axis, very wide QRS (>160 ms), and concordance in precordial leads.

Unstable tachyarrhythmia with a pulse: synchronized cardioversion; pulseless VT or VF: immediate defibrillation and CPR following ACLS.

Long QT syndrome: QTc >500 ms is high risk; avoid QT-prolonging drugs (macrolides, fluoroquinolones, ondansetron, methadone); beta-blockers are first-line therapy.

Complete heart block: indications for permanent pacing include symptomatic bradycardia, high-degree AV block, and Mobitz II; atropine is used for symptomatic bradycardia but not for high-degree block with wide QRS.

Catheter ablation is first-line for symptomatic WPW with accessory pathway, recurrent AVNRT, and selected atrial flutter/AF; cryoablation is an alternative for AVNRT.

Hypertension is defined as office BP ≥140/90 mmHg (≥130/80 in ACC/AHA guidelines); ambulatory or home monitoring confirms diagnosis and identifies white-coat and masked hypertension.

First-line antihypertensives: thiazide-like diuretics, ACEi/ARB, and calcium channel blockers; beta-blockers are preferred in CAD, HFrEF, and post-MI.

Hypertensive emergency: BP >180/120 with end-organ damage (encephalopathy, aortic dissection, pulmonary edema, AKI); use IV agents with controlled reduction (≤25% in first hour) to avoid hypoperfusion.

Aortic dissection: immediate beta-blockade (esmolol/labetalol) to target heart rate <60 bpm and SBP 100-120 mmHg before vasodilator; avoid reflex tachycardia from vasodilators alone.

Preeclampsia: BP ≥140/90 after 20 weeks with proteinuria or end-organ dysfunction; labetalol, nifedipine, and methyldopa are safe; ACEi/ARB are contraindicated in pregnancy.

Peripheral artery disease: ankle-brachial index ≤0.90 is diagnostic; supervised exercise and cilostazol improve claudication; statin and antiplatelet therapy reduce cardiovascular events.

Renal artery stenosis: fibromuscular dysplasia in young women (string-of-beads) vs atherosclerosis in older patients; ACEi/ARB may cause AKI in bilateral disease and require monitoring.

Cyanotic congenital heart disease with decreased pulmonary flow: tetralogy of Fallot (VSD, overriding aorta, RV outflow obstruction, RV hypertrophy) with squatting and hypercyanotic spells; treat spells with knee-chest position, oxygen, morphine, and beta-blocker.

Left-to-right shunts (ASD, VSD, PDA) cause pulmonary overcirculation and late Eisenmenger syndrome; closure is contraindicated once Eisenmenger physiology develops.

ASD: fixed split S2 and right heart enlargement; closure if significant shunt (Qp/Qs >1.5) before pulmonary hypertension becomes irreversible.

Coarctation of the aorta: upper-limb hypertension with weak femoral pulses and radio-femoral delay; associated with bicuspid aortic valve and Turner syndrome.

Ductus arteriosus patency in ductal-dependent lesions (e.g., transposition, pulmonary atresia) is maintained with prostaglandin E1; watch for apnea and hypotension.

Kawasaki disease: fever ≥5 days plus mucocutaneous features; IVIG and aspirin reduce coronary aneurysm risk; echocardiography at diagnosis and follow-up.

Congenital complete heart block is associated with maternal anti-Ro/SSA antibodies; pacemaker is indicated for symptomatic bradycardia or wide QRS with ventricular dysfunction.

Acute pericarditis diagnosis requires ≥2 of: chest pain, pericardial friction rub, new widespread ST elevation/PR depression, and new or worsening pericardial effusion.

First-line therapy for acute pericarditis: NSAIDs plus colchicine; corticosteroids are reserved for specific indications (autoimmune disease, renal failure) due to recurrence risk.

Cardiac tamponade: Beck triad (hypotension, muffled heart sounds, elevated JVP), pulsus paradoxus, electrical alternans, and echo findings (RA/RV diastolic collapse); treatment is pericardiocentesis.

Constrictive pericarditis: prominent y descent in JVP, pericardial knock, septal bounce, and annulus reversus; treat with diuretics and pericardiectomy for refractory cases.

Myocarditis: elevated troponin and inflammatory markers with regional wall motion abnormalities; cardiac MRI with late gadolinium enhancement aids diagnosis; restrict activity and treat HF.

Peripartum cardiomyopathy: HF within the last month of pregnancy to 5 months postpartum with LVEF <45%; treat with standard HF therapy, but ACEi/ARB and ARNI are contraindicated during breastfeeding/pregnancy.

Myocardial infarction with non-obstructive coronary arteries (MINOCA): consider plaque disruption, coronary spasm, dissection, embolism, and takotsubo; cardiac MRI clarifies the etiology.

Pooled cohort equations estimate 10-year ASCVD risk; statin therapy is recommended for LDL ≥190 mg/dL, diabetes age 40-75, and 10-year risk ≥7.5% with risk discussion.

High-intensity statin (atorvastatin 40-80 mg or rosuvastatin 20-40 mg) lowers LDL by ≥50%; add ezetimibe or PCSK9 inhibitor if LDL remains above goal.

LDL goals in very high-risk ASCVD: <55 mg/dL and ≥50% reduction from baseline; high-risk: <70 mg/dL.

Smoking cessation is the single most effective preventive intervention; varenicline, bupropion, and nicotine replacement are first-line pharmacotherapy.

Diabetes: SGLT2 inhibitors and GLP-1 receptor agonists reduce cardiovascular events; metformin remains first-line for glycemic control in most patients.

Blood pressure target is generally <130/80 mmHg for most adults, including those with diabetes and CKD, if tolerated.

Physical activity: ≥150 min/week of moderate or 75 min/week of vigorous aerobic exercise plus muscle-strengthening twice weekly.

Echocardiography: LVEF by biplane Simpson; diastolic function graded by E/A ratio, E/e', and LA volume; strain imaging detects subclinical dysfunction.

Stress testing: exercise ECG is preferred when interpretable; pharmacologic stress (dobutamine for viability, regadenoson/dipyridamole for ischemia) when exercise is not feasible.

Cardiac CT: coronary calcium score stratifies risk; CT angiography has high negative predictive value for CAD but is limited by calcification and arrhythmia.

Cardiac MRI: late gadolinium enhancement identifies scar/fibrosis (subendocardial ischemic pattern vs mid-wall nonischemic), and T1/T2 mapping detects diffuse disease and edema.

Myocardial perfusion imaging: reversible defect indicates ischemia; fixed defect indicates scar; attenuation correction improves specificity.

Troponin and BNP/NT-proBNP are key biomarkers; NT-proBNP is higher in renal dysfunction and lower in obesity, so interpret with clinical context.

Coronary angiography: FFR ≤0.80 indicates hemodynamically significant stenosis; iFR ≤0.89 is a non-hyperemic alternative.

Cardiac arrest: high-quality CPR (100-120 compressions/min, depth 5-6 cm), early defibrillation for shockable rhythms, and epinephrine 1 mg every 3-5 minutes.

Post-arrest care: targeted temperature management (32-36°C), avoid hyperoxia and hypotension, and treat reversible causes (5 H's and 5 T's).

Cardiogenic shock: SBP <90 mmHg with hypoperfusion despite volume; norepinephrine is first-line vasopressor; inotropes (dobutamine, milrinone) for low output.

Acute pulmonary edema: noninvasive ventilation, nitrates, and diuretics; avoid beta-blockers in acute decompensation with congestion.

Aortic dissection type A is a surgical emergency; type B is managed medically unless complicated by malperfusion, rupture, or refractory pain.

Pulmonary embolism with hemodynamic instability: systemic thrombolysis or catheter-directed therapy; anticoagulation for stable patients.

Tachycardia with a pulse and instability: synchronized cardioversion; for narrow-complex SVT, adenosine can be used diagnostically and therapeutically.

Beta-blockers: metoprolol succinate, bisoprolol, and carvedilol have mortality benefit in HFrEF; avoid abrupt withdrawal due to rebound ischemia.

ACEi/ARB: monitor potassium and creatinine; hold in acute kidney injury, hyperkalemia, and pregnancy; ARNI replaces ACEi but requires 36-hour washout.

Amiodarone: monitor thyroid, liver, and pulmonary function; it can prolong QT and interact with warfarin and digoxin.

Digoxin: narrow therapeutic index; toxicity worsened by hypokalemia and renal impairment; antidote is digoxin-specific Fab fragments.

Statins: monitor for myopathy and transaminase elevation; coenzyme Q10 is not routinely recommended; avoid in pregnancy.

Anticoagulants: DOACs are preferred over warfarin in nonvalvular AF; warfarin requires INR monitoring and is preferred in mechanical valves.

Diuretics: loop diuretics for congestion; monitor electrolytes and renal function; thiazides are less effective at low GFR.

Cardiac action potential phases: phase 0 (fast Na+ influx), 1 (transient K+ efflux), 2 (Ca2+ influx/K+ efflux), 3 (K+ efflux), 4 (resting potential).

Frank-Starling law: increased preload increases stroke volume up to a point, then decompensation occurs with excessive stretch.

Cardiac output = heart rate × stroke volume; stroke volume depends on preload, afterload, and contractility.

Sensitivity = TP/(TP+FN); specificity = TN/(TN+FP); positive predictive value depends on prevalence.

Randomized controlled trials reduce confounding; intention-to-treat analysis preserves randomization; per-protocol analysis assesses efficacy.

Number needed to treat = 1/absolute risk reduction; relative risk reduction can overstate clinical benefit when baseline risk is low.

Myocardial oxygen demand is determined by heart rate, contractility, and wall stress; supply depends on coronary perfusion pressure and diastolic time.