LEFT-VENTRICULAR DIASTOLIC FUNCTION - PHYSIOLOGY, METHODS OF ASSESSMENT, AND CLINICAL-SIGNIFICANCE

Diastole, that portion of the cardiac cycle that begins with isovolumi c relaxation and ends with mitral valve closure, results in ventricula r filling and involves both active (energy-dependent) and passive proc esses, The interactions between active processes (myocardial relaxatio n) that primarily influence early ventricular filling and passive proc esses, such as loading conditions, myocardial compliance, and valvular disease, are complex, Clinical methods to assess ventricular filling include cardiac catheterization, radionuclide angiography, and echocar diography, Any measurements of diastolic function must be made with an understanding of the determinants of ventricular filling and the limi tations of the diagnostic test, Many cardiac disorders are characteriz ed by elevated pulmonary venous pressures in the face of normal systol ic ventricular function, which suggests a primary abnormality of diast olic function, Abnormalities in diastolic function have been observed in coronary artery disease, congestive heart failure (with and without systolic dysfunction), hypertrophic cardiomyopathy, hypertension, and in healthy elderly subjects, Identification of these abnormalities ma y be useful clinically, particularly in patients with symptoms of hear t failure and normal systolic function, Data are not available to dete rmine the optimal therapy for such patients, although evidence suggest s that calcium channel blockers, beta blockers, and agents that revers e myocardial hypertrophy may be useful, This review briefly summarizes the physiology of diastole, the methods of clinical assessment of dia stolic function, and the role of diastolic function in cardiovascular disease.