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Biomedical subjects

D G Gibson

Publications and source records attributed to D G Gibson.

At least 235 records · Page 13Linked to original sources
PubMed1971

Plasma propranolol levels associated with suppression of ventricular ectopic beats.

The plasma propranolol levels associated with the abolition of chronic, stable ventricular ectopic beats have been studied. Racemic propranolol (DL) suppressed the ectopic foci at plasma levels of 40-85 ng/ml in eight patients, but levels of 70-200 ng/ml were unsuccessful in four patients. Dextro-(D) propranolol levels of 180-310 ng/ml were ineffective in four patients who had previously responded at levels of 60-75 ng/ml of racemic propranolol. The significance of the sympathetic nervous system in the genesis of ectopic beats is discussed. It is concluded that propranolol is clinically effective by virtue of its beta-adrenergic blocking activity.

Adult↗
PubMed1970

Phonocardiographic method of assessing changes in left ventricular function after Starr-Edwards replacement of aortic valve.

A phonocardiographic method is described for measuring the time taken by the ball of a Starr-Edwards prosthesis to move to the apex of the cage at the onset of left ventricular ejection, and from this its acceleration can be derived. The acceleration is conspicuously increased in post-ectopic beats and in exercise, but is unaffected by posture and tachycardia induced by atropine or ventricular pacing. It is suggested that the acceleration of the ball is related to the initial acceleration of blood into the ascending aorta.

Aorta, Thoracic↗
PubMed1970

Assessment of proximal tubular sodium reabsorption during water diuresis in patients with heart disease.

In order to examine the relation between cardiac state and the capacity to excrete a water load, 10 normal subjects and 61 patients with heart disease were studied during water diuresis. Under these conditions, urine flow approximates to the rate of delivery of filtrate, and therefore of sodium, from the proximal tubule of the kidney to the loop of Henle, while free water clearance is a function of distal sodium reabsorption. In 12 patients with complete heart block, ventricular pacing was associated with increased urine flow and free water clearance. Oral propranolol in 3 normal subjects and in 9 patients with intact atrial septa caused a reduction, and oral practolol in 4 normal subjects and 8 patients caused no change. In 6 patients with atrial septal defect, propranolol was without effect. Maximum urine flow correlated with left ventricular end-diastolic pressure but not mean left atrial pressure in 16 patients with chronic rheumatic heart disease. In 7 patients with ischaemic heart disease, maximum urine flow was higher than in those with chronic rheumatic heart disease and similar increase in left ventricular end-diastolic pressure. These results reflect a close relation between proximal tubular sodium reabsorption and cardiac state, and suggest that inappropriate sodium reabsorption at this site may contribute to fluid retention in heart disease.

Acetanilides↗