Use of bicycle ergometry and sustained handgrip exercise in the diagnosis of presence and extent of coronary heart disease

Abstract

The present study examines the efficacy of the exercise electrocardiogram using the isotonic bicycle ergometer and isometric handgrip in predicting the extent of coronary obstructive disease, coronary collaterals, and abnormalities of left ventricular contraction (asynergy) in 65 patients. Of 32 patients with a normal isotonic exercise electrocardiogram, 25 had a normal coronary arteriogram (78.i%). Of the 32, 7 (2I 9%) were false negatives (normal exercise electrocardiogram with abnormal coronary arteriogram). Conversely, 5 of 3I patients (i6-i%) were false positives (abnormal exercise electrocardiogram with normal coronary arteriogram). In contrast, only 3 of 53 patients tested with isometric handgrip had abnormal electrocardiograms. This correlated with the finding that the product of systolic pressure and heart rate achieved with bicycle ergometry was significantly higher (P< o.oi) than that with isometric handgrip. In the patients with abnormal coronary arteriograms, a correlation was found between the magnitude of ischaemic ST depression and the extent of coronary obstructive disease. Thus, 9 of the 14 patients with o and io mm ST segment depression exhibited one-vessel coronary disease, while only I of the I9 patients with 2 0 or greater than 2 0 mm ST segment depression had one vessel disease (P< o .oo5). A correlation was also found between the degree of ST segment depression and the presence of coronary collaterals. Only 3 of I4 patients with o and o i mm ST segment depression exhibited collaterals, while I4 of I9 patients with 2-0 or greater than 2 0 mm ST segment depression exhibited collateral vessels (P< o oo5). A similar correlation was also found between the degree of ST segment depression and the presence of asynergy. The results indicate that bicycle ergometry exercise to 70 per cent of maximum predicted heart rate is of considerable value in the diagnosis of both the presence and extent of coronary artery disease. In contrast, isometric handgrip exercise is of no value in this regard.