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Biomedical subjects

A A Luisada

Publications and source records attributed to A A Luisada.

13 recordsLinked to original sources
PubMed1977

The second heart sound in old age.

The second heart sound was studied by phonocardiography and carotid tracings in 103 elderly subjects without overt evidence of heart disease. Their ages ranged from 60 to 99 years. A normal type of splitting was found in 55.3%, and a single sound in 41.7%. The difference between these percentages and those found in 60 normal younger persons was not significant. Thus, a single second sound should not be considered a typical finding in old age. However, a reverse type of splitting, noted in only 3 patients, should be regarded as evidence of severe latent heart disease.

Adult↗
PubMed1977

On the function of the aortic valve and the mechanism of the first and second sounds.

Studies are reported on the exact timing of the aortic component of the second sound in relationship to aortic pressure and flow velocity, and also to aortic valve closure. These studies were performed in animals by means of catheter-tip probes and an electric contact introduced into the aortic valve. They were supplemented by echocardiographic stuides of the aortic valve, and impedance cardiograms in man. Opening of the aortic valve and its relationship to the first heart sound were also studied. It was observed that the second component of the first heart sound grossly coincides with the opening of the aortic valve. The aortic component of the second sound starts a few milliseconds after aortic valve closure. It starts after the incisura of the aortic pressure tracing and the drop of the velocity curve to the zero line; it then increases attaining its maximum at the peak of the rapid rebound of the aortic pressure, which coincides with the trough of the velocity tracing. The final interpretation on the mechanism of the second sound agrees in principle with the studies of Luciani, Wiggers, and Rushmer attributing the sound vibrations to release of the energy stored in the aortic wall, which accelerates the flow and causes deceleration of numerous structures (aortic and valvar) as well as of the blood. Studies of the rate of change of acceleration of pressure confirm this interpretation.

Adolescent↗
PubMed1977

What is "normal" blood pressure in the aged?

Blood pressure was studied in two groups of institutionalized subjects ranging in age from 50 to over 100 years. The first group comprised 199 selected normal subjects; subjects with any disease, including systemic hypertension, were excluded. The second group consisted of 947 unselected subjects; those with acute illness were excluded. In the first group, systolic pressure increased slightly, but diastolic pressure did not change with increasing age. The blood pressures were still within the limits that were considered normal for younger persons. In the second group, both the systolic and the diastolic pressures progressively decreased with age, so that the former fell below normal limits.

Aged↗
PubMed1977

Using noninvasive methods to study the aging heart.

Except in unusual cases, complex or invasive techniques aren't necessary to examine the heart of an elderly patient. Noninvasive methods currently being used are electrocardiography, arterial and venous pulse tracings, echocardiography, and roentgenology. Interesting data have been collected by correlating phonocardiographic with echocardiographic tracings of the mitral valve, as well as with arterial pulse tracings. Two findings that should prevent a hasty diagnosis of heart disease are that the senile heart often has an abnormal fouth sound and that a systolic murmur can be heard in one of five persons. Other studies have shown that about one-third of patients have some type of heart block and that the interval between the aortic component of the second heart sound and the peak of the early diastolic wave of the mitral echogram is longer in old persons.

Adolescent↗
PubMed1977

[The high frequency components of the heart sounds in normal subjects (author's transl)].

A technical set up for recording high frequency components of the cardiac vibrations is described. This was based on the use of several amplifiers, taking the third derivative of the displacement tracing, and using a high pass filter with a sharp slope. The tape-recorded high frequency tracing, at 500 Hz, 1000 Hz, or higher, was replayed at slower speed for accurate recording of the high speed signals. A study of the first and second hearts sound at 500 Hz and 1000 Hz was made in 14 young, normal volunteers. The high frequency vibrations of these sounds are analyzed and discussed.

Adult↗
PubMed1976

Sympathetic influence on ventricular compliance.

Intracisternal injections of veratrine in the anesthetized dog were used to study the effects of extreme sympathetic stimulation on left ventricular diastolic compliance. The results obtained were compared with those seen during volume expansion with whole blood, and after removal of both stellate ganglia. The injection of veratrine into the cisterna magna caused an increase in left ventricular end-diastolic pressure (LVEDP) which was considerably larger than that which occurred in left ventricular end-diastolic circumferential (LVEDC) segment length suggesting a reduction in diastolic compliance. There were also increases in left ventricular systolic pressure (LVSP) as well as its first derivative (LV dp/dt). Bilateral stellectomy during the veratrine response abruptly reduced LVEDP with a lesser decrease in LVEDC. Thus, the left ventricular compliance change was reversed. Both LVSP and LV dp/dt were decreased by stellectomy but remained above control levels. During transfusion, the pressure-length curve of the ventricle was located downward and to the right in comparison with the curve observed with intracisternal veratrine.

Animals↗