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Contributions of rapid filling, slow filling and atrial systole to the left ventricular (LV) filling volume were analyzed with the use of radionuclide ventriculography at rest, both globally and regionally, in 34 patients with isolated disease of the left anterior descending coronary artery. The patients included 17 with a normal ejection fraction (EF greater than or equal to 50%; group 1) and 17 with a depressed EF (less than 50%; group 2), and the data were compared with those obtained from 13 normal subjects. A computer program subdivided the LV image into 4 regions, and time-activity curves were constructed globally and regionally by reverse-gating from the R wave. In both groups the contribution of rapid filling to the LV filling volume was decreased significantly in the affected septal and apical regions, and in the global left ventricle compared with that in normal subjects. In group 1, the contribution of atrial systole showed an increase in these affected regions and in the global left ventricle. In contrast, in group 2, the atrial contribution was not increased globally or regionally as much as was expected. However, the contribution of slow filling was either increased significantly or tended to increase in the affected regions and in the global left ventricle. There were negative correlations between the contribution of rapid filling and that of slow filling in the global left ventricle (r = -0.73, p less than 0.001) and in each of the septal, apical and lateral regions (r greater than or equal to -0.60, p less than 0.001), which suggested that the contribution of slow filling as well as of atrial systole undergoes an increase as rapid filling is impaired. Thus, in patients with coronary artery disease, the left ventricle relies on slow filling as well as atrial systole to affect diastolic LV filling in the affected regions and in the global left ventricle in the presence of LV systolic dysfunction.

Contributions of late diastolic filling (slow filling and atrial systolic phases) to total filling volume in both global and regional left ventricle were analyzed using radionuclide techniques in 21 patients with isolated left anterior descending coronary artery disease without previous myocardial infarction. A computer program subdivided the image of the left ventricle into four regions at a geometric center of the area. The time-activity and its first-derivative curves of the global and regional left ventricles were computed. In the global left ventricle, the percent contributions of late diastolic filling to total filling volume were significantly increased in patients with one-vessel disease than in control subjects (20 +/- 5%, 28 +/- 4%; p less than 0.001). In the regional left ventricle, in patients with one-vessel disease, the percent contributions of late diastolic filling to total filling volume were significantly increased in the septal (25 +/- 5%, 34 +/- 8%; p less than 0.001) and in the apical regions (21 +/- 4%, 28 +/- 4%; p less than 0.001) which were perfused by stenosed vessel. In contrast, there were no significant differences in this value between the two groups in the normally perfused lateral region (22 +/- 6%, 25 +/- 5%; p = NS). These results indicate that the late diastolic filing makes a larger contribution to the left ventricular filling in the affected regions than in the normally perfused regions, and that the increased late diastolic filling in the affected regions are the cause for the increased late diastolic filling in the global left ventricle in patients with one-vessel disease.