Match each cardiovascular pathology with its most characteristic hemodynamic and echocardi… — USMLE Step 2 CK

Match each cardiovascular pathology with its most characteristic hemodynamic and echocardiographic diagnostic profile.

Cardiac tamponadeEqualization of end-diastolic pressures, a prominent x descent but absent y descent on central venous tracing, and $>25\%$ inspiratory decrease in mitral inflow velocity.
Constrictive pericarditisEqualization of end-diastolic pressures, prominent x and y descents on central venous tracing, and discordant left and right ventricular systolic pressure changes during respiration.
Restrictive cardiomyopathyElevated filling pressures with left ventricular end-diastolic pressure exceeding right ventricular end-diastolic pressure by $>5$ mmHg, and concordant ventricular pressure changes during respiration.
Right ventricular myocardial infarctionElevated right atrial and right ventricular end-diastolic pressures with low-to-normal pulmonary capillary wedge pressure, accompanied by clear lung fields and ST-segment elevations in right-sided precordial leads.
Acute massive pulmonary embolismElevated right atrial pressure, acutely elevated pulmonary artery pressures, and echocardiographic evidence of right ventricular free wall akinesis with sparing of the apex.

Cevap

The correct matches are: Cardiac tamponade with absent y descent and inspiratory inflow variation; Constrictive pericarditis with prominent y descent and discordant pressures; Restrictive cardiomyopathy with LVEDP > RVEDP and concordant pressures; Right ventricular myocardial infarction with high right-sided pressures and low-to-normal PCWP; Acute massive pulmonary embolism with elevated pulmonary pressures and McConnell's sign.

Matching these distinct pathologies requires recognizing their unique hemodynamic signatures. Cardiac tamponade is defined by an absent y descent and echocardiographic pulsus paradoxus. Constrictive pericarditis is defined by a prominent y descent and ventricular discordance. Restrictive cardiomyopathy is defined by a prominent y descent, concordant pressures, and LVEDP significantly exceeding RVEDP. Right ventricular myocardial infarction is defined by disproportionately high right-sided pressures with normal left-sided pressures. Massive pulmonary embolism is defined by acute pulmonary hypertension and specific echocardiographic right heart strain (McConnell's sign).

Adım Adım Çözüm

Analyze the central venous pressure descents for the equalization profiles.

Cardiac tamponade matches the profile with an absent y descent. Constrictive pericarditis and restrictive cardiomyopathy both have prominent y descents.

Pericardial fluid under tension in tamponade prevents early diastolic filling, abolishing the y descent. In contrast, rigid structures in constriction or restriction allow rapid early filling before halting.

Differentiate constrictive pericarditis from restrictive cardiomyopathy based on respiratory variation.

Constrictive pericarditis matches the profile with discordant ventricular pressures. Restrictive cardiomyopathy matches the profile with concordant ventricular pressures and LVEDP > RVEDP.

The rigid pericardium in constriction fixes total cardiac volume, forcing the ventricles to compete for space during respiration (discordance). Restriction lacks this constraint, so pressures rise and fall together (concordance).

Identify the cause of isolated right heart failure without pulmonary hypertension.

Right ventricular myocardial infarction matches the profile with elevated right-sided pressures and low-to-normal PCWP.

Ischemic pump failure of the right ventricle decreases forward flow into the pulmonary circulation, causing high venous pressures but preventing fluid accumulation in the lungs.

Identify the pathology associated with acute right ventricular strain from increased afterload.

Acute massive pulmonary embolism matches the profile with acutely elevated pulmonary artery pressures and right ventricular free wall akinesis sparing the apex.

A massive clot rapidly increases pulmonary vascular resistance. McConnell's sign is specific for this acute strain, as the apex remains tethered to the hyperdynamic left ventricle.

Anahtar Kavram

Hemodynamic differentiation of right heart failure and pericardial diseases

Soru

Cevap

Adım Adım Çözüm

Anahtar Kavram

Sık Yapılan Hatalar

Konular

Bu konudan daha fazla soru