APEXCARDIOGRAPHIC INDEX ”C-⊿ACG ” I. EXPERIMENTAL STUDIES
Apexcardiographic index “C-⊿ACG” was studied by animal experiments, and the results were demonstrated as follows. 1. The C point on ACG occurred almost simultaneously with a rise of the left ventricular pressure curve. 2. The peak of ⊿ACG preceded the peak dp/dt by 10.9 msec in average. However, when contractility was altered in the same individual, it was suggested that the change of “C-⊿ACG” correlated well with that of “t-peak dp/dt” and of contractility. 3. This parameter was prolonged after propranolol and was shortened after isoproterenolol. 4. While it was not possible to eradicate the effect of afterload, it was considered not possibly affected by preload. This parameter, therefore, seems to be useful for evaluating the left ventricular contractility, particularly for detecting its changes within the same subject.