Left ventricular synchrony of ejection and relaxation in coronary patients analysed by gamma angiography

The left ventricular asynchrony of both ejection and relaxation phases as also their interrelationship are analysed at rest after Dipyridamole (0.44 mg/kg) in 27 patients without previous myocardial infarction and with a normal ejection fraction at rest. The patients are divided in three groups: G0: 13 patients with no coronary artery disease (CAD), G1: 7 patients with one vessel disease and G2: 7 patients with two or three vessels disease. Two high temporal resolution sequential radionuclide ventriculographies are obtained at rest and after Dipyridamole (36 images in LAO projection). No significative variations were observed for the differences rest-Dipyridamole for the three groups and regarding the parameters derived from the global left ventricular time-activity curve: peak emptying and filling rates (PER and PFR) and their corresponding appearing times in the cardiac cycle (TPER and TPFR* = time to end systole + time to peak filling rate). New functional images representing the pixel by pixel distribution of the TPER and TPFR* are obtained, permitting the determination of the corresponding histograms. The relative variations rest-Dipyridamole of the full width at half maximum (dispersion) of the TPER histograms are different (p<0.01) between the control group G0 and the CAD patients (G1 + G2), contrary to the dispersion of the TPFR histograms. Moreover there is as linear correlation (r = 0.74, p<0.01) between the relative variations rest-Dipyridamole of the TPER versus TPFR dispersions of the CAD patients (G1 + G2). These findings suggest that the relaxation asynchrony in patients with CAD is a consequence of dysfunction of the ejection phase