Patterns of Diastolic Abnormalities during Isometric Stress in Patients with Systemic Hypertension

Abstract

This study was undertaken to determine the prevalence and distribution of diastolic function abnormalities at rest and during isometric exercise in patients with systemic hypertension using the recently introduced handgripapexcardiographic test (HAT). It has been shown that HAT reflects left ventricular pressure changes in early (relaxation) and late (compliance) diastole. A HAT was obtained in 132 patients with systemic hypertension (duration > 1 year) without history of congestive heart failure. A healthy group (n = 186) served as control subjects. Diastolic abnormalities were present at rest in 53/ 132 (40%) and during isometric handgrip stress in 92/132 (70%) patients. At rest the most frequent diastolic abnormality was the prolongation of relaxation time (27%) whereas an isolated increase in A wave was rare (8%). During isometric exercise, however, an elevation of A wave was the predominant abnormality (38%) whereas an isolated prolongation of relaxation time was less frequent (14%). Alternatively, an ‘ischemic’ pattern (abnormal prolongation of resting normal relaxation time during handgrip and/or abnormal as well as more than double increase of resting normal relative A wave to total height during or after handgrip) was observed in 29%. In 89% of these patients with an ischemic pattern of diastolic changes, a typical angina and/or positive stress ECG and/or angiographically proved coronary artery disease were present. Using HAT data the present study demonstrates for the first time that in patients with systemic hypertension: (1) diastolic abnormalities occur significantly more frequently during isometric stress than at rest, (2) the most frequently observed diastolic abnormality at rest is the relaxation time prolongation whereas during isometric stress the A wave elevation, and (3) patients with an ischemic pattern of exercise-induced diastolic abnormalities show frequently clinical or angiographic evidence of demand ischemia. Thus, HAT can become a useful additional diagnostic tool for detecting latent diastolic dysfunction and myocardial ischemia in this clinical setting.