A clinical study of left ventricular diastolic properties.

Left ventricular (LV) diastolic properties were evaluated in 150 patients with various heart diseases, including 22 normal subjects, using high fidelity pressure tracing and good quality LV cineangiogram. Impaired LV relaxation was demonstrated in hypertrophic cardiomyopathy (HCM), congestive cardiomyopathy (CCM), hypertensive heart disease (HHD), coronary artery disease (CAD) with and without LV asynergy, mitral stenosis (MS), and mitral regurgitation (MR) with significantly prolonged time constant of the LV pressure fall (time constant T). LV preload, defined as the stress to the ventricle at the end-diastole, was elevated in MR and in patients with CCM and congestive heart failure (CHF). Although LV end-diastolic pressure was high in HCM, preload was in the normal range. Diastolic elastic stiffness constant (K) was elevated in HCM, and slightly (0.05 < p < 0.1) high in HHD, and end-diastolic elastic stiffness was elevated in MR, and in patients with CCM and CHF. These observations indicate that the relaxation abnormality is present in the majority of patients with heart diseases. The elevation of preload might be a fundamental cause of LV dilatation in MR by stretching the myocardium, and the elevation of it in CCM coincides with the appearance of CHF. The chamber stiffness is increased in association with an increasing muscle mass without chamber enlargement.