Cardiovascular confusion pairs
25 Cardiovascular topics students commonly mix up on Step 2 CK, each with the fastest separator, a side-by-side comparison, and a free practice question.
Step 2 CK pairs are in open beta while clinical review finishes. Spot an issue? Tell us.
- Hypertensive emergency vs Hypertensive urgencyAcute target-organ injury at presentation is the branch point.
- STEMI vs NSTEMIST elevation in at least two contiguous leads on the first ECG is the immediate branch point to emergent reperfusion.
- Mitral stenosis vs Mitral regurgitationMurmur timing at the apex separates them immediately, with diastolic rumble for mitral stenosis versus holosystolic axillary-radiating…
- Type A aortic dissection vs Type B aortic dissectionAscending aortic involvement on emergent imaging is the single branch point for type A dissection.
- Massive PE vs Submassive PEHemodynamic instability, especially systolic BP below 90 mm Hg, is the immediate discriminator for massive PE.
- Acute limb ischemia vs Chronic limb ischemiaAbrupt onset over hours with the 6 P findings.
- Aortic stenosis vs Hypertrophic cardiomyopathyMurmur response to Valsalva maneuver.
- Acute pericarditis vs STEMIReciprocal ST depression in opposite leads points to STEMI, not uncomplicated pericarditis.
- Monomorphic VT vs Polymorphic VTUniform QRS shape means monomorphic VT, while continuously changing QRS shape means polymorphic VT.
- Stable claudication vs Critical limb ischemiaPain at rest or tissue loss identifies critical limb ischemia, not stable claudication.
- DVT vs Pulmonary embolismAcute respiratory symptoms with chest imaging evidence of pulmonary arterial clot identify PE rather than isolated DVT.
- Cardiac tamponade vs Tension pneumothoraxAbsent unilateral breath sounds with tracheal deviation identifies tension pneumothorax.
- Acute decompensated heart failure vs COPD exacerbationPulmonary vascular congestion or edema with elevated BNP favors acute decompensated heart failure.
- Wells score for DVT vs Wells score for PELeg-centric criteria apply to DVT Wells, while cardiopulmonary criteria apply to PE Wells.
- Aortic dissection vs Acute MIPulse or blood pressure differential between arms is a rapid clue for dissection.
- Third-degree AV block vs Sinus bradycardiaP waves marching through QRS complexes without a consistent PR interval identifies complete heart block.
- Stable angina vs Unstable anginaIschemic chest pain at rest or rapidly worsening frequency indicates unstable angina.
- Mobitz I (Wenckebach) vs Mobitz IIDropped beats with unchanged PR interval identify Mobitz II.
- Pericarditis vs MyocarditisNew left ventricular systolic dysfunction on echocardiography points to myocarditis.
- Atrial flutter vs Atrial fibrillationSawtooth flutter waves with a near-regular ventricular rhythm around 150/min identifies atrial flutter.
- Constrictive pericarditis vs Restrictive cardiomyopathyMarked respiratory variation in mitral inflow with septal bounce points to constrictive pericarditis.
- Systolic heart failure vs Diastolic heart failureEjection fraction on echocardiography is the fastest discriminator for systolic versus diastolic heart failure phenotype.
- Atrial fibrillation rate control vs Atrial fibrillation rhythm controlHemodynamic instability in atrial fibrillation mandates immediate synchronized cardioversion.
- HFrEF vs HFpEFEjection fraction threshold on echocardiography is the branch point: below 40% indicates HFrEF, at least 50% indicates HFpEF.
- CHADS2-VASc vs HAS-BLEDUse CHA2DS2-VASc to decide whether to anticoagulate, then use HAS-BLED to reduce bleeding risk while treating.