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Cardiovascular Pharmacology — Step 1 practice questions
61 questions in this area, with an explanation for every answer choice.
Three samples below, free and without an account.
How this shows up on Step 1
Pharmacology questions in this section combine two things the exam tests separately elsewhere. Pharmacology is examined as mechanism, effect and adverse effect, rarely as dosing. Cardiovascular questions lean heavily on physiology you can reason from first principles: pressure-volume loops, the cardiac cycle, and how preload, afterload and contractility move when something goes wrong.
Sample questions
Sample question 1
A 55-year-old man with a hypertensive emergency has been on a high-dose sodium nitroprusside infusion for 60 hours. He becomes confused, tachycardic, and develops a lactic acidosis despite adequate oxygenation, with unusually high mixed venous oxygen saturation. Which of the following is the most likely cause?
Explanations
A. Reflex sympathetic activation causing coronary ischemia
Reflex tachycardia occurs but would not explain the metabolic picture.
B. Excessive nitric oxide causing cerebral vasodilation and edema
Cerebral edema is not the mechanism of the acidosis.
C. Cyanide accumulation inhibiting cytochrome c oxidase · correct
Nitroprusside releases nitric oxide AND cyanide; with prolonged or high-dose infusion (especially with renal or hepatic impairment) cyanide overwhelms rhodanese and blocks complex IV, so tissues cannot use oxygen — lactic acidosis with a paradoxically high venous O2 saturation. Treat with hydroxocobalamin or sodium thiosulfate (and nitrites to induce methemoglobin) and stop the infusion; thiocyanate accumulates in renal failure.
D. Methemoglobinemia from nitrite formation
Methemoglobinemia can occur with nitrates but causes cyanosis with a chocolate-brown blood and normal PaO2, not high venous saturation with lactic acidosis.
E. Hypotension-induced hepatic ischemia
Hypoperfusion would lower, not raise, mixed venous O2 saturation.
Sample question 2
A stable 26-year-old has a regular narrow-complex tachycardia at 190 beats per minute with no visible P waves. Which of the following is the most appropriate initial intervention?
Explanations
A. Immediate synchronized cardioversion in a hemodynamically stable patient
Cardioversion is reserved for unstable patients.
B. Digoxin loading as the initial approach
Digoxin has slow onset and is not appropriate acutely.
C. Vagal maneuvers such as the modified Valsalva or carotid sinus massage, followed by intravenous adenosine if unsuccessful · correct
Paroxysmal supraventricular tachycardia, usually AV nodal reentrant tachycardia, depends on a reentrant circuit involving the AV node — so interventions that transiently block AV conduction terminate it. VAGAL MANEUVERS come first, with the MODIFIED Valsalva (adding leg elevation and supine positioning) substantially more effective than the standard maneuver. ADENOSINE follows, causing brief complete AV block with a characteristic sensation of chest discomfort and impending doom that patients should be warned about. Synchronized CARDIOVERSION is reserved for hemodynamic INSTABILITY.
D. Intravenous amiodarone as first-line
Amiodarone is not first-line for AV nodal reentrant tachycardia.
E. Observation without intervention
Sustained tachycardia at this rate warrants termination.
Sample question 3
Which of the following patients would most classically be considered for antibiotic prophylaxis prior to a dental procedure to prevent infective endocarditis?
Explanations
A. A patient with a prosthetic heart valve · correct
Patients with prosthetic heart valves are among the classic high-risk groups for whom antibiotic prophylaxis prior to certain dental procedures is recommended, given the high morbidity/mortality risk if endocarditis occurs on a prosthetic valve.
B. A patient with a simple, isolated atrial septal defect that has been surgically repaired without residual defect, more than 6 months prior
A repaired ASD without residual defect, more than 6 months post-repair, is generally NOT an indication for continued prophylaxis (unlike the first 6 months post-repair with prosthetic material).
C. A patient with mitral valve prolapse without regurgitation
Mitral valve prolapse WITHOUT regurgitation is not a classic indication for prophylaxis (current guidelines have narrowed indications significantly compared to older recommendations).
D. A healthy patient with no cardiac history
A healthy patient with no cardiac history does not require endocarditis prophylaxis.
E. A patient with well-controlled hypertension only
Isolated hypertension is not an indication for endocarditis prophylaxis.
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