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ABA Cardiac Anesth study materials
ABA Cardiac Anesth study resources

ABA Cardiac Anesth practice questions

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Question 1Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Left ventricular myocardial blood flow occurs predominantly during which part of the cardiac cycle?

  1. Diastole Correct answer.
  2. Peak systolic pressure development
  3. Isovolumetric contraction
  4. Rapid systolic ejection

Explanation

During systole, contracting left ventricular myocardium compresses the intramyocardial coronary vessels, so inflow is largely restricted to diastole. Diastolic flow is driven by aortic diastolic pressure minus left ventricular diastolic pressure. Tachycardia shortens diastole and therefore threatens perfusion.

Question 2Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

According to the Frank-Starling relationship, stroke volume rises primarily in response to an increase in which variable?

  1. Aortic valve orifice area and ejection time
  2. End-diastolic myocardial fiber length Correct answer.
  3. Heart rate and atrioventricular conduction velocity
  4. Systemic vascular resistance and arterial compliance

Explanation

Within physiologic limits, greater ventricular filling stretches myocytes to a longer end-diastolic sarcomere length, which increases calcium sensitivity of the contractile apparatus and augments force. The result is a larger stroke volume for a given afterload. Beyond the optimal length, further stretch reduces rather than increases force.

Question 3Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Cardiac output is calculated as heart rate multiplied by which variable?

  1. Pulmonary artery wedge pressure
  2. Systemic vascular resistance
  3. Stroke volume Correct answer.
  4. Mean arterial pressure

Explanation

Cardiac output equals heart rate times stroke volume, so either variable can raise or lower total flow. Stroke volume in turn reflects preload, afterload, and contractility. Cardiac index normalizes this value to body surface area.

Question 4Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

What is the intrinsic firing rate of the normal sinoatrial node in an adult?

  1. 40 to 60 beats/min
  2. 110 to 140 beats/min
  3. 20 to 40 beats/min
  4. 60 to 100 beats/min Correct answer.

Explanation

The sinoatrial node depolarizes spontaneously at roughly 60 to 100 impulses per minute because of its inward funny current and calcium-dependent upstroke. Subsidiary pacemakers fire more slowly, about 40 to 60 for the atrioventricular node and 20 to 40 for the His-Purkinje system. Sympathetic and vagal tone modulate this intrinsic rate.

Question 5Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Approximately what fraction of delivered oxygen does the myocardium extract at rest?

  1. 65% to 70% Correct answer.
  2. 90% to 95%
  3. 10% to 15%
  4. 25% to 30%

Explanation

The heart extracts a large fraction of arterial oxygen at rest, so increased demand must be met mainly by increasing coronary flow rather than by widening the arteriovenous oxygen difference. This limited extraction reserve makes the myocardium vulnerable when flow falls. Other organs typically extract far less and can widen their extraction when needed.

Question 6Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Stimulation of cardiac beta-1 adrenergic receptors produces which net effect?

  1. Increased contractility and heart rate Correct answer.
  2. Slowed atrioventricular nodal conduction
  3. Peripheral arterial vasoconstriction mediated by alpha-1 receptors
  4. Coronary vasoconstriction with reduced myocardial flow

Explanation

Beta-1 receptors couple to Gs proteins and raise intracellular cyclic AMP, which enhances the slow inward calcium current in nodal and myocardial cells. The result is positive inotropy, chronotropy, and dromotropy with increased myocardial oxygen consumption. Vascular alpha-1 effects and beta-2 vasodilation are separate receptor responses.

Question 7Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Increased vagal (parasympathetic) traffic to the heart typically produces which change?

  1. Slowed heart rate and atrioventricular conduction Correct answer.
  2. Increased contractility of ventricular myocytes
  3. Accelerated atrioventricular nodal conduction
  4. Coronary vasoconstriction with reduced flow

Explanation

Acetylcholine acts on M2 receptors to reduce the pacemaker current and to hyperpolarize nodal cells, slowing the sinus rate and atrioventricular conduction. Vagal effects predominate at the atria and the atrioventricular node, with little direct influence on ventricular contractility. Pronounced vagal tone can produce bradycardia and hypotension.

Question 8Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Most coronary venous blood drains through the coronary sinus directly into which chamber?

  1. Right atrium Correct answer.
  2. Pulmonary artery
  3. Superior vena cava
  4. Left atrium

Explanation

The coronary sinus opens into the right atrium near the inferior vena caval junction and carries the majority of coronary venous return. The anterior cardiac veins and Thebesian veins provide smaller alternative drainage routes. Coronary sinus flow can be sampled to estimate myocardial oxygen extraction.

Question 9Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

A patient has an aortic diastolic pressure of 50 mm Hg and a left ventricular end-diastolic pressure of 20 mm Hg. What is the left ventricular coronary perfusion pressure?

  1. 100 mm Hg
  2. 50 mm Hg
  3. 30 mm Hg Correct answer.
  4. 70 mm Hg

Explanation

Left ventricular coronary perfusion pressure is approximated as aortic diastolic pressure minus left ventricular end-diastolic pressure, because coronary inflow is a diastolic event. Here 50 minus 20 equals 30 mm Hg, a value low enough to threaten subendocardial perfusion. The gradient, not the absolute diastolic pressure alone, determines driving force.

Question 10Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Why does marked sinus tachycardia impair left ventricular perfusion?

  1. Shortened diastole limits perfusion while oxygen demand rises Correct answer.
  2. It lowers myocardial oxygen consumption by reducing contractility
  3. It prolongs the isovolumetric relaxation period
  4. It increases diastolic aortic pressure more than systolic pressure

Explanation

Coronary inflow to the left ventricle occurs mainly in diastole, so a faster rate cuts the time available for perfusion at the same time that increased contractile work raises oxygen demand. Supply therefore falls while demand rises, and the subendocardium is affected first. Beta blockade slows the rate and restores the diastolic interval.

Question 11Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Which principle best explains the high myocardial oxygen demand of a chronically dilated left ventricle?

  1. Greater heart rate prolongs diastolic filling and coronary flow
  2. A larger chamber radius raises wall tension for any given pressure Correct answer.
  3. The Frank-Starling mechanism lowers oxygen requirements as volume rises
  4. Reduced preload lowers myocardial wall stress and oxygen use

Explanation

By the Laplace relationship, wall tension is proportional to intracavitary pressure and chamber radius and inversely proportional to wall thickness. A dilated ventricle therefore generates more tension, and thus more oxygen demand, to produce the same pressure. This is why afterload reduction can improve mechanics in a failing, dilated heart.

Question 12Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

A patient has a mean arterial pressure of 90 mm Hg, a central venous pressure of 10 mm Hg, and a cardiac output of 5 L/min. What is the systemic vascular resistance in dyn·s·cm⁻⁵?

  1. 1280 dyn·s·cm⁻⁵ Correct answer.
  2. 800 dyn·s·cm⁻⁵
  3. 1600 dyn·s·cm⁻⁵
  4. 2000 dyn·s·cm⁻⁵

Explanation

Systemic vascular resistance is calculated as mean arterial pressure minus central venous pressure, divided by cardiac output, then multiplied by 80 to convert to dyn·s·cm⁻⁵. Here 80 divided by 5 equals 16 Wood units, and 16 times 80 equals 1280 dyn·s·cm⁻⁵. Omitting the central venous pressure gives an erroneously high value.

Question 13Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Which hemodynamic pattern best describes an induction dose of propofol in a patient with coronary artery disease?

  1. Selective pulmonary vasoconstriction with right ventricular failure
  2. Vasodilation with direct myocardial depression Correct answer.
  3. Rising systemic vascular resistance with reflex bradycardia
  4. Sympathetic stimulation with hypertension and tachycardia

Explanation

Propofol causes arteriolar and venous dilation and blunts sympathetic outflow, so mean arterial pressure falls, sometimes substantially. It also depresses myocardial contractility while reducing myocardial oxygen consumption. The fall in diastolic pressure can reduce coronary perfusion, which is undesirable in a fixed stenosis.

Question 14Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Which induction agent is most appropriate for a hypovolemic patient with severe aortic stenosis because of its hemodynamic stability?

  1. Thiopental
  2. Propofol
  3. Sevoflurane at 2 MAC
  4. Etomidate Correct answer.

Explanation

Etomidate produces minimal change in systemic vascular resistance, preload, and contractility, so it preserves the perfusion pressure and systemic resistance on which a stenotic circulation depends. Propofol, thiopental, and high concentrations of volatile agents all cause vasodilation or myocardial depression. Etomidate's main drawback is transient adrenal suppression.

Question 15Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Which property of ketamine makes it useful for induction in a patient with hemorrhagic shock?

  1. Selective reduction of systemic vascular resistance
  2. Profound vagotonia with bradycardia
  3. Direct coronary vasoconstriction
  4. Sympathomimetic support of blood pressure Correct answer.

Explanation

Ketamine increases sympathetic outflow and inhibits norepinephrine reuptake, so blood pressure and heart rate are usually maintained despite hypovolemia. This makes it attractive when vasodilation would be dangerous, although the tachycardia it causes can be harmful in ischemic heart disease. Because catecholamine stores may be depleted, hypotension can still occur in profound shock.

Question 16Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Milrinone improves cardiac output through which primary mechanism?

  1. Beta-1 adrenergic receptor agonism
  2. Inhibition of the sodium-potassium ATPase
  3. Inhibition of phosphodiesterase-3 Correct answer.
  4. Blockade of L-type calcium channels

Explanation

Milrinone inhibits phosphodiesterase-3, raising intracellular cyclic AMP and increasing calcium availability in myocardial cells while enhancing relaxation. It is both an inotrope and a vasodilator, so hypotension is a common adverse effect. Because it acts distal to the beta receptor, it remains effective in patients taking beta blockers.

Question 17Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

At usual clinical doses, nitroglycerin reduces myocardial oxygen demand mainly by which action?

  1. Increased heart rate that shortens diastolic filling time
  2. Predominant venodilation that reduces preload and wall stress Correct answer.
  3. Arteriolar constriction that raises systemic vascular resistance
  4. Direct negative inotropy on ventricular myocytes

Explanation

Nitroglycerin releases nitric oxide, which dilates capacitance vessels and lowers ventricular filling pressures and wall stress, thereby cutting oxygen demand. Higher doses also dilate coronary arteries and relieve spasm, improving supply. Reflex tachycardia is a potential drawback that can blunt the benefit.

Question 18Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Over what approximate range of mean arterial pressure does the normal coronary circulation autoregulate flow?

  1. 140 to 180 mm Hg
  2. 60 to 140 mm Hg Correct answer.
  3. 20 to 60 mm Hg
  4. 180 to 220 mm Hg

Explanation

Within roughly 60 to 140 mm Hg mean arterial pressure, coronary flow remains relatively constant because arteriolar tone adjusts to metabolic demand. Outside this range, flow becomes pressure dependent, and below the lower limit subendocardial ischemia develops. A critical stenosis shifts the whole autoregulatory curve so that flow falls at higher pressures.

Question 19Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Phase 0 of the ventricular myocyte action potential is produced by which current?

  1. Slow calcium influx through L-type channels
  2. Potassium efflux through inward rectifier channels
  3. Sodium-calcium exchange extruding intracellular calcium
  4. Rapid sodium influx through fast voltage-gated channels Correct answer.

Explanation

Ventricular depolarization depends on a rapid inward sodium current through voltage-gated channels, giving the fast upstroke. Calcium entry through L-type channels generates the plateau, while potassium currents drive repolarization. Sodium channel blockade slows phase 0 and widens the QRS complex.

Question 20Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Which metabolic change most directly explains the rapid loss of contractility during acute myocardial ischemia?

  1. Increased fatty acid oxidation with intracellular alkalosis
  2. Anaerobic glycolysis with lactate buildup and falling ATP Correct answer.
  3. Enhanced oxidative phosphorylation with excess ATP production
  4. Activation of the sodium-potassium pump with hyperpolarization

Explanation

When coronary flow stops, oxygen delivery ceases and the myocardium must rely on anaerobic glycolysis, which yields little ATP and generates lactate. Falling ATP impairs calcium handling and cross-bridge cycling, so force declines within seconds. Lactate accumulation and intracellular acidosis further depress contractility and can trigger arrhythmias.

Question 21Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

A patient with a critical left anterior descending stenosis develops regional ischemia after dipyridamole administration. Which mechanism best explains this?

  1. Steal of flow toward normal, vasodilated territories Correct answer.
  2. Venodilation that lowers diastolic coronary perfusion pressure
  3. Marked tachycardia that raises myocardial oxygen demand
  4. Alpha-adrenergic coronary vasoconstriction at the stenosis

Explanation

Dipyridamole blocks adenosine reuptake and dilates normal arterioles, but the post-stenotic bed is already maximally dilated and cannot respond further. Pressure distal to the stenosis falls as flow is diverted to normal territories, producing a transmural steal. This principle underlies stress perfusion imaging.

Question 22Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

In the Guyton model, steady-state venous return is determined primarily by the difference between which two pressures?

  1. Intrapericardial pressure and pleural pressure
  2. Aortic pressure and intrathoracic pressure
  3. Mean systemic filling pressure and right atrial pressure Correct answer.
  4. Pulmonary capillary wedge pressure and left atrial pressure

Explanation

Venous return equals mean systemic filling pressure minus right atrial pressure, divided by the resistance to venous return. Interventions that raise right atrial pressure, such as positive-pressure ventilation or tamponade, reduce the gradient and thus cardiac output. Raising stressed blood volume with fluid or vasoconstriction increases the gradient.

Question 23Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Severe bupivacaine toxicity characteristically produces refractory cardiac arrest through which mechanism?

  1. Cardiac sodium channel blockade Correct answer.
  2. Uncoupling of oxidative phosphorylation in mitochondria
  3. Direct activation of cardiac L-type calcium channels
  4. Catecholamine depletion at sympathetic nerve terminals

Explanation

Bupivacaine is highly lipid soluble and binds cardiac sodium channels avidly, slowing conduction and producing wide-complex ventricular arrhythmias that can be refractory to standard resuscitation. It also depresses myocardial contractility. Intravenous lipid emulsion is used because it sequesters the drug and may restore channel function.

Question 24Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Three days after an inferior myocardial infarction, a patient develops sudden pulmonary edema, hypotension, and a new systolic murmur. Which structure has most likely ruptured?

  1. Anterolateral papillary muscle
  2. Membranous interventricular septum
  3. Aortic valve commissure
  4. Posteromedial papillary muscle Correct answer.

Explanation

The posteromedial papillary muscle usually has a single blood supply from the posterior descending artery, a branch of the right coronary artery, so inferior infarction can cause it to rupture and produce acute severe mitral regurgitation. Left atrial pressure rises abruptly, giving flash pulmonary edema and a new systolic murmur. The anterolateral papillary muscle has a dual blood supply and ruptures less often.

Question 25Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Which characteristic best explains why the subendocardium is the region most vulnerable to ischemia?

  1. Greater capillary density than the epicardium
  2. Perfusion mainly during systole at high pressure
  3. Highest wall stress with the least flow reserve Correct answer.
  4. Highest resting blood flow per gram of tissue

Explanation

Subendocardial fibers lie furthest from the epicardial surface and are compressed most during systole, so they depend on diastolic perfusion and normally extract near-maximal oxygen. Wall stress is highest there and autoregulatory reserve is lowest, so any fall in perfusion pressure or rise in demand produces subendocardial ischemia first. This is why subendocardial infarction appears as an inner-wall lesion.

Question 26Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

In most people, the sinoatrial node receives its arterial blood supply from which vessel?

  1. Left anterior descending artery
  2. Left main coronary artery
  3. Left circumflex artery
  4. Right coronary artery Correct answer.

Explanation

The sinoatrial node is usually supplied by a branch of the right coronary artery, although a substantial minority of people have supply from the left circumflex. This anatomy explains why right coronary occlusion can produce sinus node ischemia and bradyarrhythmias.

Question 27Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

According to the Frank-Starling relationship, an increase in left ventricular end-diastolic volume within the physiologic range produces which change?

  1. Reduced myocardial fiber shortening
  2. Decreased stroke volume
  3. Increased stroke volume Correct answer.
  4. Decreased peak systolic pressure

Explanation

Within physiologic limits, greater end-diastolic volume stretches myocardial sarcomeres toward a more optimal length, increasing the force of contraction and stroke volume. This is the basis for preload-dependent augmentation of cardiac output in the normal ventricle.

Question 28Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

A patient's left ventricular pressure-volume loop shows a steeper end-systolic pressure-volume relationship after an infusion of dobutamine. This change indicates which effect?

  1. Reduced afterload
  2. Increased contractility Correct answer.
  3. Impaired relaxation
  4. Increased preload

Explanation

The slope of the end-systolic pressure-volume relationship reflects ventricular contractility, and a steeper slope indicates a positive inotropic effect. Dobutamine increases contractility, shifting the end-systolic relationship upward and leftward.

Question 29Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

During maintenance of anesthesia with 1.5 MAC sevoflurane, a patient develops a 20% decrease in mean arterial pressure with a compensatory increase in heart rate. Which mechanism most directly explains the hypotension?

  1. Increased systemic vascular resistance
  2. Enhanced baroreceptor sensitivity
  3. Direct myocardial depression and vasodilation Correct answer.
  4. Increased venous return

Explanation

Volatile anesthetics produce dose-dependent arterial vasodilation and direct myocardial depression, both of which lower mean arterial pressure. Baroreflex-mediated tachycardia may occur but is usually blunted by the anesthetic.

Question 30Fundamentals of Cardiac Anesthesia (cardiovascular anatomy, physiology, and pharmacology)

Which best explains why right ventricular myocardial perfusion continues during systole, whereas left ventricular subendocardial perfusion is predominantly diastolic?

  1. Right ventricular wall tension exceeds aortic pressure during systole.
  2. Right ventricular systolic pressure is much lower than aortic pressure, preserving a systolic perfusion gradient. Correct answer.
  3. The right coronary artery has lower resistance than the left coronary artery.
  4. The right ventricle receives most of its blood from the coronary sinus.

Explanation

Right ventricular systolic pressure is normally far below aortic pressure, so a coronary perfusion gradient persists even during systole. In the left ventricle, systolic wall tension approaches or exceeds aortic pressure, so subendocardial flow occurs mainly in diastole.

Question 31Preoperative Evaluation, Risk Assessment, and Optimization

Which item is a component of the Revised Cardiac Risk Index (RCRI)?

  1. Left ventricular ejection fraction below 30%
  2. Uncontrolled systemic hypertension
  3. History of heart failure Correct answer.
  4. Moderate aortic stenosis

Explanation

The RCRI assigns one point each for high-risk surgery, ischemic heart disease, heart failure, cerebrovascular disease, insulin-treated diabetes, and preoperative creatinine above 2.0 mg/dL. Ejection fraction, valve disease, and hypertension are not components of the index.

Question 32Preoperative Evaluation, Risk Assessment, and Optimization

A patient reports being able to climb one flight of stairs without stopping. This corresponds to approximately which functional capacity?

  1. 10 METs
  2. 0.5 METs
  3. 4 METs or greater Correct answer.
  4. 1 to 2 METs

Explanation

Climbing a flight of stairs requires about 4 METs and is a commonly used threshold for adequate functional capacity. Patients who can achieve 4 METs or more generally tolerate most operations, whereas lower capacity suggests higher risk.

Question 33Preoperative Evaluation, Risk Assessment, and Optimization

Which patient most clearly warrants a preoperative 12-lead ECG before elective surgery?

  1. A 28-year-old with a recent resolved upper respiratory infection
  2. A 68-year-old with known heart failure having open cholecystectomy Correct answer.
  3. A 30-year-old having knee arthroscopy
  4. A 45-year-old with no symptoms having cataract surgery

Explanation

A preoperative ECG is reasonable when there is known cardiac disease or when the surgery carries elevated risk. Asymptomatic patients undergoing low-risk procedures generally do not need routine ECG testing.

Question 34Preoperative Evaluation, Risk Assessment, and Optimization

A patient with severe persistent asthma and known coronary disease cannot exercise. Which pharmacologic stress test is most appropriate?

  1. Adenosine single-photon emission imaging
  2. Regadenoson single-photon emission imaging
  3. Dobutamine stress echocardiography Correct answer.
  4. Dipyridamole single-photon emission imaging

Explanation

Adenosine, dipyridamole, and regadenoson can provoke bronchospasm in patients with severe reactive airway disease. Dobutamine stress testing is therefore preferred when adenosine receptor agonists are risky.

Question 35Preoperative Evaluation, Risk Assessment, and Optimization

A patient takes metoprolol succinate daily for coronary disease and is scheduled for elective CABG. What is the best perioperative approach?

  1. Stop it 48 hours before surgery
  2. Start high-dose metoprolol on the morning of surgery
  3. Replace it with diltiazem on the day of surgery
  4. Continue the beta-blocker through surgery Correct answer.

Explanation

Chronic beta-blockade should be continued perioperatively to avoid withdrawal and reduce ischemic risk. Acutely starting high-dose beta-blockade on the day of surgery increases bradycardia and hypotension and has been associated with harm.

Question 36Preoperative Evaluation, Risk Assessment, and Optimization

A patient taking atorvastatin 40 mg daily for secondary prevention is scheduled for elective CABG. What is the best approach to the statin?

  1. Continue it through surgery Correct answer.
  2. Discontinue it and start niacin
  3. Stop it 3 days before surgery
  4. Hold it on the morning of surgery only

Explanation

Statins should generally be continued through the perioperative period because withdrawal has been associated with worse cardiac outcomes. Routine discontinuation before cardiac surgery is not advised.

Question 37Preoperative Evaluation, Risk Assessment, and Optimization

A patient underwent placement of a drug-eluting stent for acute coronary syndrome 4 months ago and now needs elective hernia repair. What is the safest plan?

  1. Delay surgery for at least six months and continue aspirin Correct answer.
  2. Proceed now after holding clopidogrel for five days
  3. Proceed now after holding aspirin for five days
  4. Delay surgery for twelve months and stop both antiplatelet drugs

Explanation

Elective surgery after drug-eluting stent placement is generally deferred for at least six months, and aspirin is usually continued. Premature interruption of dual antiplatelet therapy risks stent thrombosis, which can be catastrophic.

Question 38Preoperative Evaluation, Risk Assessment, and Optimization

Which statement best reflects current evidence about continuing ACE inhibitors or ARBs before cardiac surgery?

  1. They should always be replaced by a calcium channel blocker before cardiac surgery
  2. Individualize therapy; continuation may cause hypotension without proven benefit Correct answer.
  3. Routine continuation clearly reduces mortality and should be universal
  4. Routine withdrawal clearly reduces mortality and should be universal

Explanation

Continuing ACE inhibitors or ARBs increases the risk of intraoperative hypotension and vasoplegia, but a clear mortality benefit from routine continuation has not been established. Guidelines therefore support an individualized approach, often holding the morning dose in patients at high risk of hypotension.

Question 39Preoperative Evaluation, Risk Assessment, and Optimization

A patient with type 2 diabetes takes empagliflozin and is scheduled for elective CABG. When should the drug be stopped before surgery?

  1. On the morning of surgery
  2. Three days before surgery Correct answer.
  3. It does not need to be stopped
  4. Ten days before surgery

Explanation

SGLT2 inhibitors are generally held about three days before surgery to reduce the risk of euglycemic diabetic ketoacidosis. Ertugliflozin is held slightly longer, about four days.

Question 40Preoperative Evaluation, Risk Assessment, and Optimization

Which patient most clearly requires bridging anticoagulation after warfarin is interrupted for elective surgery?

  1. A patient with a mechanical mitral valve Correct answer.
  2. A patient with a prior provoked DVT 5 years ago
  3. A patient with a bioprosthetic aortic valve placed 2 years ago
  4. A patient with atrial fibrillation and CHA2DS2-VASc score of 2

Explanation

Bridging is generally reserved for patients at highest thrombotic risk, such as those with a mechanical mitral valve or a recent venous thromboembolism. Lower-risk conditions usually do not require bridging.

Question 41Preoperative Evaluation, Risk Assessment, and Optimization

Which preoperative finding is the strongest predictor of perioperative risk in a patient with pulmonary hypertension undergoing major surgery?

  1. A history of obstructive sleep apnea
  2. WHO functional class IV symptoms Correct answer.
  3. A loud pulmonic component of S2
  4. Mild tricuspid regurgitation on echocardiography

Explanation

Functional class, right ventricular function, and right atrial pressure are key determinants of perioperative risk in pulmonary hypertension. WHO functional class IV symptoms indicate severe limitation and very high risk.

Question 42Preoperative Evaluation, Risk Assessment, and Optimization

A patient with asymptomatic severe aortic stenosis (valve area 0.8 cm², mean gradient 45 mm Hg) needs elective colon resection. What is the best recommendation?

  1. Proceed after a normal dobutamine stress test
  2. Proceed with surgery under neuraxial anesthesia
  3. Perform balloon aortic valvuloplasty before the surgery
  4. Refer for valve replacement before elective surgery Correct answer.

Explanation

Severe aortic stenosis is a major perioperative risk, and elective noncardiac surgery is generally deferred until the valve has been addressed. Valve replacement should be considered before elective surgery in such patients.

Question 43Preoperative Evaluation, Risk Assessment, and Optimization

Which combination represents guideline-directed medical therapy for heart failure with reduced ejection fraction?

  1. Calcium channel blocker, statin, aspirin, long-acting nitrate
  2. Beta-blocker, verapamil, hydralazine, furosemide
  3. ARNI, beta-blocker, MRA, SGLT2 inhibitor Correct answer.
  4. Diuretic, digoxin, amiodarone, warfarin

Explanation

The four pillars of guideline-directed therapy for heart failure with reduced ejection fraction are renin-angiotensin system inhibition with an ARNI or ACE inhibitor/ARB, an evidence-based beta-blocker, a mineralocorticoid receptor antagonist, and an SGLT2 inhibitor. These agents reduce mortality and hospitalization.

Question 44Preoperative Evaluation, Risk Assessment, and Optimization

Preoperative natriuretic peptide measurement is most useful for which purpose?

  1. Diagnosing infective valvular endocarditis
  2. Assessing renal function
  3. Excluding significant coronary artery disease
  4. Risk stratification in suspected heart failure Correct answer.

Explanation

Elevated BNP or NT-proBNP is associated with adverse perioperative cardiac events and helps stratify risk in patients with known or suspected heart failure. It is not a test for coronary anatomy, endocarditis, or renal function.

Question 45Preoperative Evaluation, Risk Assessment, and Optimization

Which finding is part of the Fried frailty phenotype?

  1. Serum albumin below 2.5 g/dL
  2. Weak grip strength Correct answer.
  3. Hemoglobin A1c above 8%
  4. Body mass index above 30

Explanation

The Fried phenotype includes unintentional weight loss, exhaustion, low physical activity, slow gait speed, and weak grip strength. Obesity, glycemic control, and hypoalbuminemia are not components of this phenotype.

Question 46Preoperative Evaluation, Risk Assessment, and Optimization

A magnet is placed over an implanted cardioverter-defibrillator during surgery. What is the expected effect?

  1. Permanent deactivation of the device
  2. Suspends antitachycardia therapy but preserves brady pacing Correct answer.
  3. Conversion to asynchronous pacing at a fixed rate of 60 beats/min
  4. Inhibition of bradycardia pacing

Explanation

An ICD magnet suspends antitachycardia therapies while usually leaving bradycardia pacing unaffected. A pacemaker magnet, by contrast, typically produces asynchronous pacing.

Question 47Preoperative Evaluation, Risk Assessment, and Optimization

Which strategy is most effective for reducing contrast-induced acute kidney injury in a patient with chronic kidney disease undergoing coronary angiography?

  1. Oral N-acetylcysteine
  2. Sodium bicarbonate, which is clearly superior
  3. Intravenous isotonic crystalloid Correct answer.
  4. Intravenous mannitol

Explanation

Volume expansion with isotonic intravenous crystalloid is the mainstay of prevention of contrast-induced acute kidney injury. Mannitol and N-acetylcysteine are not proven, and sodium bicarbonate has not been shown to be clearly superior.

Question 48Preoperative Evaluation, Risk Assessment, and Optimization

A patient with iron-deficiency anemia (hemoglobin 9.5 g/dL) is scheduled for elective cardiac surgery. What is the best next step?

  1. Start erythropoietin without iron studies
  2. Evaluate and treat iron deficiency before surgery Correct answer.
  3. Proceed without further evaluation
  4. Transfuse to a hemoglobin of 10 g/dL and proceed

Explanation

Preoperative anemia should be investigated and treated, including correction of iron deficiency when present. Routine transfusion to a fixed hemoglobin threshold of 10 g/dL is not recommended and carries its own risks.

Question 49Preoperative Evaluation, Risk Assessment, and Optimization

An HbA1c above which value is commonly used to postpone elective surgery for further glycemic optimization?

  1. 10.0%
  2. 6.0%
  3. 8.0% Correct answer.
  4. 7.0%

Explanation

An HbA1c above 8% is commonly used as a threshold to optimize diabetes control before elective surgery. This threshold identifies patients at increased risk of perioperative hyperglycemia and related complications.

Question 50Preoperative Evaluation, Risk Assessment, and Optimization

How long before surgery should a smoker ideally quit to gain meaningful reduction in pulmonary complications?

  1. At least 1 day
  2. At least 3 days
  3. At least 4 weeks Correct answer.
  4. At least 6 months

Explanation

At least four weeks of smoking abstinence before surgery is associated with fewer pulmonary complications, and longer abstinence is even better. Very short intervals do not provide the same benefit.