Apex-carotis diagram as related to systolic and diastolic time intervals in myocardial infarction.

Simultaneous recordings of the electrocardiogram, phonocardiogram carotid pulse tracing and left apex cardiogram were obtained in 32 patients with myocardial infarction and 62 normal subjects. This allowed to measure systolic and diastolic time intervals and to construct the apex-carotis diagram (ACD), a new mechanocardiographic method which integrates the carotid pulse tracing and the apexcardiogram in an orthogonal coordinate system. In myocardial infarction, the ACD showed a decrease of the field of ventricular filling, a decrease of the field of ventricular ejection and an increase of the diastolic subsegment. A. The measurement of time intervals showed statistically significant information in those which were directly related to the deformation of the ACD in patients with myocardial infarction.