Biochemical and histologic correlates of ventricular end-diastolic pressure

The associations of elevated left ventricular (LV) and right ventricular (RV) end-diastolic pressure (EDP) were evaluated in 28 patients with non-ischemic congestive cardiomyopathy. Right-sided endomyocardial biopsies from each patient were evaluated for ATP content, percent fibrosis and myocardial fiber diameter. The resting RVEDP and LVEDP and the post-angiographic LVEDP were correlated with the results from the biopsies. There was a correlation of the LVEDP with the RVEDP (r = 0.67, P less than 0.001) by a linear plot. There was no correlation of any EDP measurement with the percent fibrosis. There was, however, a rough correlation of the myocardial fiber diameter with RVEDP (r = 0.40, P less than 0.05). Myocardial ATP content correlated with the RVEDP (r = -0.53, P less than 0.005), the LVEDP (r = -0.65, P less than 0.001) and the post-angiographic LVEDP (r = -0.72, P less than 0.001). These data demonstrate that an elevated ventricular EDP correlates most closely with depressed levels of myocardial ATP. The myocardial cell diameter correlated less well and there was no correlation of EDP with fibrosis. Metabolic factors may be more important than histologic parameters in the elevated ventricular EDP of non-ischemic congestive cardiomyopathy.