2007 Laennec Clinician/Educator Lecture—Unraveling the Mysteries of Diastology

Abstract

Diastolic dysfunction plays a critical role in the pathophysiology of producing signs and symptoms of heart failure. Heart failure with a normal ejection fraction (HFnlEF) is one of the leading causes of hospital admissions today and is associated with significant morbidity and mortality. It is thus important to understand the pathophysiology of diastolic dysfunction, which itself is a complex series of multiple interrelated events, including relaxation, suction, ventricular interaction, ventricular arterial coupling, pericardial restraint, and myocardial viscoelastic forces. It was difficult for the clinician to understand “diastology” in the past. Initial studies were limited to complex equations derived from animal models and were difficult to apply to patient care. The development of radionuclide angiography and Doppler echocardiography allowed noninvasive rapid assessment of volumetric filling and flow velocity curves, which began to provide insight into the complex process of diastolic filling for the clinician. As our understanding of diastology evolved over the past 2 decades, it has become clear that we now need to pursue new areas to understand this fascinating subject and apply it to patient care. These areas include the underlying mechanism HFnlEF (ventricular-vascular coupling versus true myocardial stiffness), relationship of rest versus exercise hemodynamics, and the complex ventricular fiber “twisting and shortening” of both contraction and relaxation.