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Biomedical subjects

S Wolfson

Publications and source records attributed to S Wolfson.

At least 55 records · Page 3Linked to original sources
PubMed1976

N-dimethylisopropyl propranolol. Effects on myocardial oxygen demands.

N-Dimethylisopropyl propranolol (DMP) is a quaternary derivative which lacks significant beta-adrenergic blocking and local anesthetic effects. It has been reported, nonetheless, to be effective in treating experimental arrhythmias and in limiting the extent of ST-segment elevations following experimental coronary occlusion. The present study examined the effects of DMP on the hemodynamics and myocardial oxygen demands of anesthetized dogs. After a single dose of 3 mg/kg, heart rate fell from 146 +/- 8 to 124 +/- 6 beats/min (P less than 0.0025), and aortic systolic pressure fell from 151 +/- 11 to 141 +/- 9 mm Hg (0.05 less than P less than 0.10), resulting in a 16.8% reduction in the tension-time index. Stroke volume was reduced by 10% despite a 54% increase in left ventricular end-diastolic pressure, suggesting a negative inotropic effect. This was supported by a decrease in maximum extrapolated contractile element velocity from 9.10 +/- 1.05 to 6.61 +/- 65 units/sec (P less than 0.0025). Myocardial oxygen consumption was reduced from 12.0 +/- 1.4 to 9.9 +/- 1.5 ml/min/100 g tissue (P less than 0.05). Myocardial oxygen extraction was unchanged, indicating that the decrease in oxygen consumption resulted from a reduction in myocardial oxygen demand. When heart rate and systolic pressure were artificially restored to control levels, after the administration of DMP, myocardial oxygen consumption remained significantly below the control level. DMP, therefore, appeared to reduce myocardial oxygen demands primarily by its negative inotropic effect. This drug may have application in the treatment of ischemic heart disease.

Animals↗
PubMed1976

Regional cardiac prostaglandin release during myocardial ischemia in anesthetized dogs.

Cardiac prostaglandin release was studied in closed-chest dogs during acute coronary occlusion. Aortic and coronary sinus blood was obtained before, and at intervals after, balloon occlusion of the left anterior descending artery in seven dogs. Samples were assayed for prostaglandins F, E, and A by randioimmunoassay. All dogs demonstrated prostaglandin F release, Mean +/- SE postocclusion aortic levels were 0.26 +/- 0.01 ng/ml; coronary sinus levels were 0.67 +/- 0.01 ng/ml (P less than 0.001). In six dogs, prostaglandin E also was released. Mean postocclusion aortic levels were 0.24 +/- 0.01 ng/ml; coronary sinus, 0.44 +/- 0.01 ng/ml (P less than 0.001). There was no release of prostaglandin A. To examine the site of prostaglandin release, simultaneous samples from the aorta, the coronary sinus, and the great cardiac vein were obtained before and after left circumflex artery occlusion in six additional studies. The great cardiac vein drained effluent from nonischemic myocardium, whereas the coronary sinus drainage included blood from both ischemic and nonischemic zones. All six dogs demonstrated prostaglandin F release from the ischemic region. Mean postocclusion aortic prostaglandin F was 0.32 +/- 0.01 ng/ml. Coronary sinus prostaglandin F was 1.69 +/- 0.03 ng/ml (P less than 0.001), whereas the great cardiac vein level remained at 0.34 +/- 0.01 ng/ml (P greater than 0.05). Prostaglandin E was released from both ischemic and nonischemic regions. Mean aortic prostaglandin E was 0.21 +/- 0.01 ng/ml; great cardiac vein, 0.55 +/- 0.02 ng/ml (P less than 0.001); and coronary sinus, 1.07 +/- 0.04 ng/ml (P less than 0.001). These results have led us to conclude that the different local availability of prostaglandins E and F may influence the cardiac response to ischemia.

Animals↗
PubMed1975

Retrograde catheterization of the left atrium in idiopathic hypertrophic subaortic stenosis.

Retrograde catheterization of the left atrium utilizing the Shirley technique was successfully performed in four patients with idiopathic hypertrophic subaortic stenosis. By traversing the inflow tract of the left ventricle on pullback from the left atrium to the aorta, this method served to separate definitively true hypertrophic subaortic stenosis from cavity obliteration. It was accomplished with relative ease and no complications. In patients with suspected idiopathic hypertrophic subaortic stenosis who are to have retrograde left heart catheterization, this approach to the left atrium is recommended as an alternative to the transseptal technique.

Adult↗
PubMed1975

Quantitative relationships between potassium-43 imaging and left ventricular cineangiography following myocardial infarction in man.

To evaluate the quantitative relationships between resting potassium-43 (43K) myocardial imaging and left ventricular segmental contraction abnormalities, 15 patients were studied by both radionuclide and contrast angiographic techniques at least two months following transmural myocardial infarction. The ECG location of infarction involved the anterior wall alone in six patients, inferior wall alone in three patients, both anterior and inferior walls in five patients, and in one patient ECG-anatomic correlation was obscured by newly developed left bundle branch block. 43K defects were noted in all patients. Anterior wall 43K defects were noted in all patients with previous anterior infarction and seven of nine inferior infarcts. These 43K defects were associated with a quantifiable decrease in regional radioactivity of at least 20% of normal appearing zones, and their location correlated with the angiographic site of akinesis or dyskinesis. The extent of the 43K defect (% 43K HP [% potassium 43 hypoperfusion]) was measured by planimetry and averaged 49% of the anterior view image (range 25-66%), 43% of the left anterior oblique image (range 0-58%), with the mean of both views being 47% (range 17-62%). The mean total area of the anterior image was 58 cm2 (range 40-101 cm2). The extent of the 43K defect (% 43K HP) was related to the extent of segmental contraction abnormality (% ACS). Correlations between % ACS and anterior view % 43K HP (r = 0.67), left anterior oblique % 43K HP (r = 0.54), and mean % 43K HP (r = 0.77) were found. The total size of the anterior view image correlated with left ventricular end-diastolic volume (r = 0.79). Thus, in this initial group of patients following transmural infarction, potassium-43 imaging can be accurately and quantitatively correlated with the site and extent of regional ventricular dysfunction as it is assessed by quantitative left ventricular angiography.

Acute Disease↗