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Biomedical subjects

B S Alpert

Publications and source records attributed to B S Alpert.

At least 145 records · Page 8Linked to original sources
PubMed1981

Hemodynamic and ECG responses to exercise in children with sickle cell anemia.

To determine whether exercise responses are different from normal in children with sickle cell anemia (SCA), we performed dynamic cycle ergometer exercise testing in 47 patients with SCA, aged 5 to 18 years, and 170 healthy, black age-matched control subjects. Seven (15%) of the patients with SCA had definitely ischemic, 16 (34%) had equivocally ischemic, and 24 (51%) had nonischemic ECG responses. Resting heart rate in the three groups of patients with SCA was higher than control values. Maximum exercise heart rate attained was lowest in the definitely ischemic group. All patients with SCA had decreased blood pressure responses and maximum working capacity when compared with control subjects. Hemoglobin concentration was lowest in the definitely ischemic group and correlated with maximum workload. Long-term myocardial ischemia may lead to fibrosis and the decreased myocardial contractility seen in adult patients with SCA.

Adolescent↗
PubMed1981

Peak left ventricular pressure/volume (Emax) during exercise in control subjects and children with left-sided cardiac disease.

The peak ratio of left ventricular systolic pressure/systolic volume (PV) has been shown to be a close approximation to Emax, an index of contractility independent of both preload and afterload. We studied 17 children with left-sided cardiac disease during catheterization by a combined high-fidelity catheter and m-mode echocardiographic technique. Emax, indexed for body surface area, was calculated at rest and during supine exercise at 25% and 50% of maximal upright workload. In addition, we studied 15 control subjects with a noninvasive approximation of peak P/V, the peak systolic LV pressure/smallest systolic LV volume. Patients with left ventricular pressure overload showed an increased Emax value at rest and a further increase with exercise. Patients with left ventricular volume overload or cardiomyopathy had a normal value of Emax at rest and had only small increases with exercise. Patients with both volume and pressure overload had a resting Emax value that was increased, but no further increase occurred with exercise. Emax in children seems to be a sensitive index of contractility during physiologic stress and can be used to assess left ventricular functional reserve capacity both pre- and post-operatively.

Adolescent↗
PubMed1981

Blood pressure response to dynamic exercise in healthy children--black vs white.

In order to determine normal values for systolic blood pressure response to cycle ergometer stress testing in children, we performed 405 studies in subjects from 6 to 15 years of age, of whom 184 were black and 221 were white. We analyzed the data in relation to sex, color, age, and body surface area. Resting systolic blood pressure showed no differences between groups of black and white children, analyzed either by age or surface area. Peak exercise blood pressures were higher in the black females, in comparison to their white counterparts, only when separated into groups by body surface area. The black males had higher exercise blood pressure values than the whites, both by age and surface area evaluation. Our data suggest a difference in the blood pressure response to dynamic exercise within the black population. Further studies are needed to define the mechanism of this difference and whether this difference may provide a clue to the identification of children at increased risk for developing hypertension later in life.

Adolescent↗
PubMed1981

Digital replantation.

Most of the technical problems of digital replantation have been resolved, but restoration of damaged joints and free gliding of tendons still defy the replantation surgeon. The restoration of function can be enhanced after the reparative process by encouraging motivation in the patient and by a persistent, supervised program of rehabilitation. Attainment of structural and anatomic integrity does not guarantee good function: some patients achieve useful function in spite of a greatly reduced number of parts of the hand and unremarkable initial recovery. Replantation surgeons working as a team have the technical skill to provide the injured patient with a chance for recovery of lost function. Lost digits never function.

Adult↗
PubMed1980

Hemodynamic responses to supine exercise in children with left-sided cardiac disease.

Exercise, a physiologic stress, has been used in adults to unmask abnormalities of left ventricular hemodynamics not detectable at rest. Similar data in children are not available. An evaluation was made of the feasibility, safety and value of a graded upright and supine ergometer stress test to assess exercise hemodynamics during cardiac catheterization in 21 children with left-sided cardiac disease. The catheterization technique involved the simultaneous recording of intracardiac and great vessel pressures, thermodilution cardiac index and M mode echocardiograms of the left ventricular cavity. The method appears practical and safe. Although hemodynamic responses varied among clinical groups, the lack of control data currently prevents assessment of the value of this technique for long-term management.

Adolescent↗
PubMed1980

Assessment of left ventricular contractility during supine exercise in children with left-sided cardiac disease.

Exercise stresses the cardiovascular system and causes it to use its reserve capacities. Exercise assessment may unmask abnormalities of left ventricular contractility not suspected from or detected by resting measurements. We have studied the following indices of left ventricular contractility in 21 children with left-sided congenital heart disease: maximum dP/dt, Vmax, Vpm, Vcf, and peak meridional wall stress. Studies were performed in the supine posture at rest, and at 25 per cent, and 50 per cent of a predetermined maximal upright workload on a bicycle ergometer. The method of measurement used simultaneous high fidelity catheter pressure tracings and M-mode echocardiography. There were no complications and the technique appeared practical and safe. The measurements of contractility differentiated patients with left ventricular volume or pressure overload from each other and from patients with either volume plus pressure overload, or myocardial dysfunction. These measurements can be used to measure the functional reserve capacity of patients with left-sided lesions, and may be useful in follow-up studies, especially before and after operation.

Adolescent↗
PubMed1980

Advances in muscle and musculocutaneous flaps.

The use of the muscle and musculocutaneous unit as a reconstructive tool by the plastic and reconstructive surgeon is expanding to all body regions. The initial four basic factors required in use of the muscle flap for reconstructive surgery now include such modifications as: (1) transfer of the sensory nerve to the musculocutaneous unit with the flap for sensory preservation; (2) use of minor vascular pedicles as a point of rotation for certain muscle flaps, (3) use of combinations of more than one muscle flap with common proximal vascular supply; and (4) transfer of the bony origin of the muscle unit with the muscle flap. Refinements and further additions to this list are demonstrated throughout this text and will certainly increase as the muscle flap is adapted for use in coverage of difficult wounds. An accurate knowledge of the vascular anatomy of muscles will allow safe modifications in the design of the muscle and musculocutaneous unit by the reconstructive surgeon.

Fascia Lata↗
PubMed1979

Role of the renin-angiotensin-aldosterone system in hypertensive children with coarctation of the aorta.

To investigate the role of the renin-angiotensin-aldosterone system as a cause of hypertension, 20 hypertensive patients with coarctation of the aorta were studied during normal and low sodium intake and after diuresis with flurosemide. Eight patients with essential hypertension and 13 control subjects were similarly studied. Plasma renin activity values in patients with coarctation were similar to those in patients with essential hypertension and in control patients during normal and low sodium diets. However, after the administration of furosemide, plasma renin activity values were significantly higher in the patients with coarctation than in the other two groups (P less than 0.005 and less than 0.01, respectively). The values for urinary aldosterone, plasma volume and extracell fluid volume (bromide space) were increased in patients with coarctation during both normal and low sodium intake. These renin and aldosterone responses and body fluid spaces in patients with coarctation suggest that their hypertension resembles a one-kidney Goldblatt model. The data help to better define the role of the renin-angiotensin-aldosterone system in the hypertension of coarctation and thus may help guide the clinician in therapeutic interventions.

Adolescent↗
PubMed1979

A severe complication of pulmonary vein angiography.

A pulmonary vein angiogram was performed using a pressure injection with the tip of an end and side hole catheter in a near-wedge position; extravasation of contrast material into a bronchus occurred, causing severe bronchoconstriction. It may be possible to avoid this complication by the use of an end hole balloon catheter in the wedge position, slow flow rates of contrast material, and low pressure injections.

Angiography↗