Adult Echocardiography Practice Exam

An epicardial notch during early systole on M-mode may indicate which condition?

1. Constrictive pericarditis

2. Cardiac tamponade

3. Pericarditis

4. Myocardial infarction

The correct answer is: Cardiac tamponade

An epicardial notch observed during early systole on M-mode is indicative of cardiac tamponade. In this condition, an accumulation of fluid in the pericardial space exerts pressure on the heart, particularly affecting the diastolic filling of the ventricles. As the heart contracts and tries to pump blood during systole, the increased pressure can manifest as a notch or dip in the epicardial motion seen in M-mode echocardiography. This notch essentially reflects impaired ventricular function due to the restriction caused by the surrounding fluid, illustrating the heart's response to the abnormal fluid accumulation. Understanding the significance of the epicardial notch helps in distinguishing cardiac tamponade from other conditions, as each of those conditions produces distinct echocardiographic features. In constrictive pericarditis, for instance, the heart is also restricted but might present differently, and pericarditis alone does not necessarily lead to the iconic sign of a notch. Myocardial infarction may show motion abnormalities of the myocardium but not typically an epicardial notch during early systole in M-mode.