The relationship of alterations in systolic time intervals to ejection fraction in patients with cardiac disease.

SUMMARY The relationships between the systolic time intervals determined from simultaneous recordings of the electrocardiogram, the phonocardiogram, the carotid arterial pulse tracing, and direct measures of left ventricular performance as assessed angiographically by measurement of left ventricular stroke volume (SV), end-diastolic volume (EDV), and ejection fraction (EF) were studied in 68 patients with a wide variety of cardiac diseases. The systolic intervals, the pre-ejection period (PEP), the left ventricular ejection time (LVET), and the ratio PEP/LVET, each correlated significantly with angio-graphically determined EF and EDV. Closest correlation was observed between PEP/ LVET and EF (r =-0.90). The systolic intervals correlated only slightly with the angio-graphically determined SV. These data lend additional evidence supporting the use of systolic time intervals as a non-invasive measure of left ventricular performance in patients with cardiac disease. Additional Indexing Words: Angiocardiogram Ratio of pre-ejection period to left ventricular ejection time Non-invasive technic T HE RE HAS BEEN recent resurgence of interest in utilizing non-invasive technics for the evaluation of cardiovascular dynamics and myocardial performance in man. It has been demonstrated that the systolic time intervals obtained from the electrocardiogram, phonocardiogram, and carotid pulse tracing are related to stroke volume, cardiac output, and the clinical status of patients with congestive heart failure due to arteriosclerotic, hypertensive, and primary myocardial disease. 1 2 Specifically, the pre-ejection period is prolonged and the left ventricular ejection time is shortened in these patients. A composite expression of these changes in the systolic time intervals is afforded by the ratio of the pre-ejection period to the left ventricular ejection time. In previous studies the systolic time intervals have not been related to more direct measures of left ventricular performance. The purpose of this report is to present studies on the relationships between the systolic time intervals and the left ventricular ejection fraction obtained from quantitative cardiac angiography in patients with various forms of cardiovascular disease. Methods The systolic time intervals were obtained from stimultaneous recordings of the electrocardio-gram, phonocardiogram, and carotid arterial pulse tracing at a paper speed of 100 mm/sec using a multichannel photographic system (Electronics for Medicine). The Y lead in the Frank vectorial system was used to determine the onset of 455