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Cardiovascular System — Step 1 practice questions
251 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
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. Murmurs are usually presented as a description rather than a sound, so the skill being tested is translating timing and location into a lesion. Pharmacology appears constantly, most often as a mechanism question wearing a clinical vignette.
Sample questions
Sample question 1
A patient has a holosystolic murmur heard best at the apex radiating to the axilla, with a soft S1 and an S3. Which of the following is the most likely lesion?
Explanations
A. Mitral stenosis with an opening snap and diastolic rumble
Mitral stenosis produces a diastolic murmur.
B. Mitral regurgitation, in which retrograde flow into the left atrium throughout systole produces a holosystolic apical murmur radiating to the axilla · correct
Mitral regurgitation produces a HOLOSYSTOLIC murmur because the pressure gradient between ventricle and atrium exists throughout systole, heard best at the APEX with radiation to the AXILLA, often with a soft S1 and an S3 from the volume-loaded ventricle. Contrast the other left-sided lesions: AORTIC STENOSIS gives a crescendo-decrescendo systolic murmur at the right upper sternal border radiating to the carotids with delayed carotid upstroke; MITRAL STENOSIS gives an opening snap with a diastolic rumble; and AORTIC REGURGITATION gives an early decrescendo diastolic murmur with a wide pulse pressure.
C. Aortic stenosis with a crescendo-decrescendo murmur radiating to the carotids
Aortic stenosis radiates to the carotids and is not holosystolic.
D. Tricuspid regurgitation increasing with expiration
Right-sided murmurs increase with INSPIRATION.
E. Aortic regurgitation with a decrescendo diastolic murmur
Aortic regurgitation is diastolic.
Sample question 2
An arteriole constricts, reducing its radius by half while pressure gradient and viscosity remain constant. Which of the following best describes the effect on flow through that vessel?
Explanations
A. Flow falls to one-half of baseline, varying linearly with radius
A linear relationship would grossly underestimate the effect.
B. Flow falls to about one-sixteenth of baseline, because flow varies with the fourth power of the radius · correct
By the Poiseuille relationship, flow is proportional to the fourth power of the radius and inversely proportional to length and viscosity. Halving the radius therefore reduces flow to (1/2)⁴ = 1/16 of baseline. This extraordinary sensitivity explains why arterioles are the principal resistance vessels and why small changes in their tone dominate systemic vascular resistance and organ perfusion — and why even modest luminal narrowing in a coronary artery has outsized hemodynamic consequences.
C. Flow is unchanged because the pressure gradient is constant
Resistance changes alter flow even at fixed driving pressure.
D. Flow doubles because velocity increases
Velocity may rise locally, but volumetric flow falls.
E. Flow falls to one-quarter of baseline, varying with the square of radius
Cross-sectional area varies with the square, but flow varies with the fourth power.
Sample question 3
A patient recovering from an episode of syncope due to ventricular arrhythmia asks when he may resume driving. Which of the following is the most appropriate response?
Explanations
A. Permanently prohibit driving regardless of treatment
Restrictions are typically time-limited and depend on treatment.
B. Advise a period of driving restriction based on the cause and treatment, document the counseling, and follow jurisdictional reporting requirements, since driving after arrhythmic syncope poses risk to the patient and the public · correct
Syncope from a ventricular arrhythmia creates risk of recurrence at the wheel, endangering the patient and third parties. Guidance specifies restriction periods that depend on cause, treatment, and whether driving is private or commercial — for example, defined intervals after defibrillator implantation or after an arrhythmic event. The physician's obligations are to counsel clearly, DOCUMENT the discussion, and follow local reporting law, which varies from mandatory reporting to physician discretion.
C. Tell the patient there are no restrictions after arrhythmic syncope
Unrestricted driving after arrhythmic syncope is unsafe.
D. Report the patient to law enforcement immediately in all jurisdictions
Reporting requirements vary; counseling and documentation come first.
E. Leave the decision entirely to the patient without discussion
Failing to counsel neglects a duty to the patient and the public.
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