HQ TIME IN CONGESTIVE CARDIOMYOPATHIES

1. 1. In 41 per cent of patients with COCM there was a bundle branch block. All but one of these 18 patients showed a prolonged HQ time, indicating that the whole conduction system in these cases is involved and that there is just a predominance of one side. 2. 2. Fifty-nine per cent had a normal QRS complex and 50 per cent of these patients showed a prolonged HQ time. It must be assumed that in these cases the whole conduction system is diffusely involved to the same degree. This results in a pure HQ prolongation and not in bundle branch block. 3. 3. Patients with ICM showed significantly less often an HQ prolongation, indicating that the conduction system in these cases is not diffusely involved. 4. 4. The significant negative correlation between HQ time and EF indicates that the progression of the myocardial disease is concomitant with the progression of the conduction disturbances, which can be either diffuse in both branches, leading to a pure HQ prolongation, or be predominant in one of the bundles, leading to a bundle branch block with an HQ prolongation. 5. 5. There are no significant differences of the end-diastolic volumes within the group of COCM and between patients with COCM and ICM. Thus, ventricular enlargement, and myocardial dilatation, respectively, are not the cause of HQ prolongation. © 1979.