DIAGNOSTIC-VALUE OF STRESS-CARDIOMYOGRAPH Y COMPARED WITH STRESS-ELECTROCARDIOGRAPHY

Early recognition of ischemic heart disease (IHD) is one of the main g oals of noninvasive cardiology. Because of the rather low sensitivity of exercise electrocardiography (ECG) it seems reasonable to look for other cost-efficient noninvasive methods for the improvement of the de tection of IHD. In this study a recently developed cardiokymographic d evice (CKG) which is capable of recording precordial cardiac impulses during physical exercise was used to detect IHD. The results were comp ared with exercise ECG. 54 patients who had coronary angiography durin g the previous 3 months underwent supine exercise ECG and simultaneous CKG stress-testing. 23 healthy subjects served as controls. ECG-crite ria for ischemia were ST-segment depression of greater-than-or-equal-t o 1.5 mm in at least one precordial lead (V4-V6). CKG-criteria for isc hemia were late or holosystolic bulging (type 2 or type 3). Global sen sitivity of the exercise-CKG for a diameter-reduction of greater-than- or-equal-to 50% of at least one major coronary artery was 68% (95% con fidence limits, CI 53-80), the specificity was 91% (95% CI 72-99). In contrast sensitivity of the exercise-ECG was 52% (95% CI 37-68) and sp ecificity was 96% (95% CI 78-100). Predictive values for the positive test were 94% and 96% respectively. For patients with three-vessel-dis ease, left main stem disease or two vessel disease with critical invol vement of the left anterior descending coronary artery (LAD) the sensi tivity was 89% (ECG 64%), for the group with LAD stenosis 60% (ECG 53% ) and for the group with significant circumflex or right coronary arte ry disease 50% (ECG 40%). By combined testing with CKG and ECG the sen sitivity was improved (91%, 95% CI 73-94), with only slightly lower sp ecificity (87%, 95% CI 66-97) and the predictive value for the positiv e test was 93%. In case of a concordant positive test result the sensi tivity was only 32% (95% CI 2149), however the specificity and the pre dictive value for the positive test were 100% (95% CI 85-100). In thos e patients who had positive test-results, CKG showed a trend towards e arlier discernible ischemia. In conclusion, combined ECG-CKG-exercise- testing may be superior to exercise ECG alone, in particular for detec ting multi-vessel disease.