Match each clinical presentation of a myocardial infarction complication with its most characteristic hemodynamic finding on right heart catheterization.
- A patient develops a harsh holosystolic murmur at the left lower sternal border with a palpable thrill 4 days after an anteroapical myocardial infarction.Significant step-up in blood oxygen saturation between the right atrium and the right ventricle.
- A patient develops a new, soft holosystolic murmur at the apex and sudden-onset severe pulmonary edema 3 days after an inferior myocardial infarction.Abrupt elevation of the pulmonary capillary wedge pressure tracing during ventricular systole (giant 'v' waves).
- A patient experiences sudden-onset pulseless electrical activity and distended neck veins 5 days after a transmural anterior myocardial infarction.Equalization of diastolic pressures across all cardiac chambers with an absent or blunted 'y' descent on the right atrial tracing.
- A patient presents with clear lungs, marked jugular venous distention, and profound hypotension immediately upon arrival for an acute inferior myocardial infarction.Disproportionately elevated right atrial pressure relative to pulmonary capillary wedge pressure, accompanied by a steep 'y' descent.
Answer
The presentations map to their respective hemodynamic profiles as follows: Ventricular septal rupture presents with an oxygen step-up in the right ventricle; papillary muscle rupture presents with giant 'v' waves on the pulmonary capillary wedge pressure tracing; left ventricular free wall rupture presents with equalization of diastolic pressures and an absent 'y' descent; right ventricular infarction presents with elevated right atrial pressure and a steep 'y' descent.
Matching each complication with its hemodynamic profile requires a two-step physiological deduction. Ventricular septal ruptures produce left-to-right shunting at the ventricular level, increasing right ventricular oxygenation. Acute mitral regurgitation from papillary muscle rupture forces blood back into the pulmonary circulation during systole, abruptly spiking the pulmonary capillary wedge pressure tracing (giant 'v' waves). Free wall ruptures cause cardiac tamponade, externally compressing all chambers and equalizing their diastolic pressures while blunting atrial emptying ('y' descent). Finally, right ventricular infarctions cause right-sided pump failure, backing up blood into the right atrium while the left heart remains under-filled.
Step-by-Step Solution
Key Concept
Diagnosis and hemodynamic profiling of acute myocardial infarction complications.
Estimated Time:2m 30s