Noninvasive assessment of segmental left ventricular wall motion: Its clinical relevance in detection of ischemia

Abstract Newly developed noninvasive techniques, using fluoroscopic, electromagnetic, ultrasonic and nuclear medical devices, now make evaluation of segmental wall motion (SWM) widely applicable to man. Experiments in open chest animal preparations have demonstrated that SWM abnormalities (SWMA) are sensitive and specific markers of ischemia. Following coronary occlusion in closed chest dogs, using various techniques, we observed the same sequence of SWMA over a similar time course. In 122 angiographically documented patients, SWMA assessed by stress cardiokymography (CKG) revealed a sensitivity of 74% and a specificity of 94% in detecting coronary heart disease (CHD). The combined predictive power of stress ECG/CKG was superior to either test alone. Using radionuclide equilibrium scintigraphy and sitting bicycle exercise, stress induced SWMA revealed a sensitivity of 84% in detecting CHD. SWMA were detected in nearly all patients 24 h after acute transmural myocardial infarction (MI). These abnormalities extended beyond the location predicted by ST segment elevation and Q waves in the ECG, significantly more in anterior (15/16) than inferior (9/16) MI (p < 0.05). In inferior MI, precordial ST segment depression was frequently (8/10) associated with anterior SWMA, indicative of ischemia rather than of a reciprocal electrical phenomenon. Scintigraphic assessment of left ventricular SWM correlated poorly with calculated CK‐MB infarct size (r = 0.64), suggesting that left ventricular function is determined not only by the necrotic zone but is also related to dysfunction of ischemic segments. SWM of the infarcted as well as the remote zone of the left ventricle showed no consistent directional changes within 10 days after infarction. In conclusion, noninvasive analysis of SWM is of clinical relevance 1. during diagnostic stress testing to detect ischemia, 2. in chronic stable CHD to assess the extent of mechanical dysfunction, 3. in acute MI to localize and assess extent and severity of regional myocardial dysfunction.