USEFULNESS OF NONINVASIVE DETECTION OF LEFT-VENTRICULAR DIASTOLIC ABNORMALITIES DURING ISOMETRIC STRESS IN HYPERTROPHIC CARDIOMYOPATHY AND IN ATHLETES

We showed previously that the handgrip apexcardiographic test (HAT) is a useful method for detecting left ventricular (LV) diastolic abnorma lities in patients with coronary artery disease and systemic hypertens ion, This study evaluates the use of HAT for assessing the prevalence and types of exercise-induced diastolic abnormalities in patients with obstructive (n = 31) and nonobstructive (n = 35) hypertrophic cardiom yopathy (HC) as well as its potential value for separating healthy sub jects and athletes from patients with HC. We obtained a HAT in 66 cons ecutive patients with HC and in 72 controls (52 healthy volunteers and 20 athletes), A positive HAT was defined by the presence of one of th e following: (1) relative A wave to fetal height (A/H) during or after handgrip >21% (compliance type), (2) total apexcardiographic relaxati on time (TART) >143 ms or the heart rate corrected TART (TARTI) during handgrip <0.14, (relaxation type), (3) both types present (mixed type ), and (4) diastolic amplitude time index (DATI = TARTI/[A/D]) during handgrip <0.27. Of the controls, only 1 of 52 healthy subjects and 1 o f 20 athletes showed a positive HAT, whereas of the total HC cohort 63 of 66 patients (95%) herd a positive result. There was no significant difference in the distribution of these types between obstructive and nonobstructive HC. Further, no LV diastolic abnormalities were presen t in 10 of 35 patients (29%) with nanobstructive HC at rest and in 3 o f 35 patients (9%) during handgrip, whereas of the patients with obstr uctive HC only 1 of 31 (3%) had no LV diastolic abnormalities at rest and none during handgrip. Based on HAT data, our study demonstrates th at in HC (1) LV diastolic abnormalities are very frequent during handg rip; (2) patients with nonobstructive HC show significantly fewer LV d iastolic abnormalities at rest than those with obstructive HC; and (3) no significant difference exists between obstructive and nonobstructi ve HC in the prevalence of types of handgrip-induced LV diastolic abno rmalities. Consequently, HAT appears to be of clinical value as an add itional tool for separating normal patients and athletes from patients with HC. (C) 1998 by Excerpta Medics, Inc.