New index of cardiac contractility during stress testing with treadmill.

Experimental demonstration that the external phonocardiogram is similar to the third derivative (rate of acceleration) of LV pressure, and that catecholamines cause a similar increase of the early systolic wave of the first derivative of LV pressure and of S1 prompted a study of the first sound during stress testing. Following a previous study with different types of ergometers, the present investigation was based on records of 10 normal, young volunteers, taken during treadmill exercise while a phonocardiogram was recorded at the apex. The first heart sound increased in all of them averaging an eightfold increase during maximal stress.

Transmission delays of different portions of the arterial pulse. A comparison between the indirect aortic and carotid pulse tracings.

The transmission delays of the upstroke and incisura of the arterial pulse were measured in 128 normal subjects, divided in three groups of increasing age, by comparing the timing of the indirect aortic arch pulse (recorded at the suprasternal notch) (SSN) and the indirect, right carotid tracing (CAR). In the total group, the mean delay of the upstroke was 24.4 msec while the mean delay of the incisura was 19 msec (P less than 0.

The pulmonary component of the second heart sound in acquired aortic stenosis.

The amplitude of the pulmonic component of the second sound in aortic stenosis was studied in 49 patients with this lesion. As controls, 50 normal subjects were also studied. Both groups were investigated by phonocardiography, apex cardiography and arterial tracings.

Abnormal left ventricular contraction revealed by impedance cardiograms and arterial tracings in bundle branch blocks and old myocardial infarcts.

Following the observation of an unusual pattern of the first derivative of the impedance cardiogram in cases of bundle branch block, a systematic study was performed both in normal controls and clinical cases. This graphic study was supplemented by the simultaneous recording of the first derivative of an arterial tracing, preferably the indirect aortic pulse at the suprasternal notch. These studies were performed in 70 subjects: 30 normal subjects, 14 cases of right bundle branch block, 14 cases of left bundle branch block, and 12 cases of old infarcts.

Changes of cardiac output caused by aging: an impedance cardiographic study.

The various parameters of cardiac output were studied in 132 healthy subjects from 20 to 89 years of age by impedance cardiography. This noninvasive method supplied data that were similar to those found by others by dye dilution methods. All parameters of cardiac output decrease with age.