Noninvasive detection of coronary artery disease by assessing diastolic abnormalities during low isometric exercise

The handgrip‐apexcardiographic test (HAT) is a simple low‐level (40% of maximal voluntary handgrip during 2 min) stress test which can detect left ventricular (LV) diastolic abnormalities. To determine whether it contributes to the diagnosis of coronary artery disease (CAD), HAT was obtained in 68 patients–47 with and 21 without angina pectoris–who prospectively underwent coronary arteriography. According to the highest or lowest individual values of diastolic apexcardiographic indices in 255 healthy volunteers, a pathologic or positive HAT was defined by the presence of at least one of the following new criteria: (1) A wave relative to total height of apexcardiogram during and/or after handgrip>21%, (2) total apexcardiographic relaxation time (TART) during handgrip>TART at rest > 143 ms and/or TART corrected for the duration of diastole (TARTT) during handgrip <0.14, or (3) diastolic amplitude time index (DATI), given by dividing TAR‐TI and A wave relative to total diastolic amplitude of apex tracing during handgrip<0.27. HAT was positive in 20 of 21 patients with single‐vessel disease (sensitivity 95%), 21 of 24 patients with double‐vessel disease (sensitivity 88%), and in 22 of 23 patients with triple‐vessel disease (sensitivity 96%). Furthermore, HAT was positive in 20 of 21 (95%) patients without symptoms. Thus, the overall sensitivity of HAT for detecting CAD was 93%. This study is the first to demonstrate the high sensitivity of HAT in identifying patients with CAD with or without symptoms by assessing diastolic apexcardiographic abnormalities during low‐level isometric stress. Thus, HAT potentially could become an additional simple diagnostic tool for noninvasive detection of patients with CAD.