Influence of dipyridamole-induced cardiac ischemia on the high-resolution ECG - evaluation by 201-thallium SPECT imaging

Late potentials represent an arrhythmic substrate in chronically infarcted myocardium. Since the majority of patients suffering sustained ventricular arrhythmias have coronary artery disease, it was hypothesized that acute transient ischemia enhances anisotropic, delayed electrical ventricular activation and facilitates reentry mechanisms. The current study aim was the assessment of the influence of dipyridamole induced acute myocardial ischemia on the high-resolution signal-averaged ECG. Confirmed 201-thallium-SPECT imaging was used to identify, and locate ischemia in 68 patients with suspected coronary artery disease. Before and during dipyridamole effect SAECG was carried out. 33/68 patients revealed a dipyridamole induced ischemia, but no ischemia induced changes of the SAECG parameters QRS, RMS and LAS at 25-250 and 40-250 Hz bandpass filtering in the leads X, Y, Z and vector magnitude, respectively, Moreover, induced ischemia did not influence the outcome of the time-domain analysis.<>