Measuring diastolic function with transmitral flow propagation velocity: more than just a pretty picture?

摘要

THE CARDIAC CYCLE has 2 phases: systole and diastole. Clinicians tend to think of systole as the active and perhaps more important phase in which the blood is pumped forward, and of diastole as the more passive phase of ventricular filling. This began to change in the 1980s when many patients with congestive heart failure were found by noninvasive tests such as echocardi-ography and nuclear scanning to have good or even normal systolic function, giving rise to the notion that abnormality of the diastolie phase of the cycle, diastolic dysfunction, was an important cause of cardiac pathophysiology. Left ventricular diastolic function is complex and consists of at least 2 discernible processes that may contribute to diastolic dysfunction: myocardiai relaxation, an active, energy-consuming sequestration of calcium in early diastole, and ventricular compliance, the passive stretching of the myocardium in later diastole resisted by the extracellular matrix, consisting primarily of collagen.