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Biomedical subjects

S Wolfson

Publications and source records attributed to S Wolfson.

At least 37 records · Page 2Linked to original sources
PubMed1981

Randomized comparison of the modified wire-guided and standard intra-aortic balloon catheters.

We have designed a modified intra-aortic balloon (IAB) catheter to facilitate balloon insertion and minimize the complications of vascular dissection, perforation, and thrombosis. The modified balloon catheter is fabricated of a new polyurethane, Avcomat-100; it has a central lumen which allows for pressure monitoring, contrast injection, and introduction of a guide-wire under fluoroscopic control. In a randomized study, we compared the modified balloon with the standard Avco balloon catheter. Eighteen patients were randomized, 10 to receive a standard balloon catheter (control group) and eight to receive a modified balloon catheter. In two of the 10 patients assigned to the control group, introduction of the standard catheter failed but a central-lumen balloon was successfully introduced using the guide wire. A guide wire was needed for introduction of the modified balloon in three of the eight patients assigned to the central-lumen catheter group. The Avcomat-100 catheter material was less thrombogenic, with a lower rate of femoral thrombosis--20% in the control group and 0% in the central-lumen group. Scanning electron miroscopy also showed a reduced area of catheter surface covered with fibrin and clot. This study demonstrates the safety, decreased thrombogenicity, and increased facility of insertion of this new balloon catheter.

Adult↗
PubMed1980

Lyme carditis: cardiac abnormalities of Lyme disease.

We studied 20 patients, mostly young adult men, with cardiac involvement of Lyme disease. The commonest abnormality (18 patients) was fluctuating degrees of atrioventricular block; eight of them developed complete heart block. Thirteen patients had evidence of more diffuse cardiac involvement: electrocardiographic changes compatible with acute myopericarditis (11 patients), radionuclide evidence of mild left ventricular dysfunction (five of 12 patients tested), or frank cardiomegaly (one patient). Heart involvement was usually preceded by erythema chronicum migrans and sometimes accompanied by meningoencephalitis, facial palsy, arthritis, elevated serum IgM levels, or cryoglobulins containing IgM. The duration of cardiac involvement was usually brief (3 days to 6 weeks). The clinical picture in these patients has similarities to acute rheumatic fever; but in Lyme disease, complete heart block may be commoner, myopericardial involvement tends to be milder, and valves seem not to be affected.

Adult↗
PubMed1979

Wernicke's and global aphasia without alexia.

It has been proposed that the comprehension of written language requires transcoding from the visual (grapheme) to the auditory (phoneme). It has also been proposed that visual word images can be comprehended without grapheme-phoneme transcoding. We describe three aphasic patients with left hemisphere impairment who had poor speech comprehension but could comprehend written language. One of these patients had a subsequent right hemisphere lesion and lost his ability to read. We propose that the right hemisphere in some individuals may be capable of extracting semantic information from iconic images (ideogram) without phonological processing.

Adult↗
PubMed1978

Retrograde left ventricular catheterization in patients with an aortic valve prosthesis.

Twenty-seven consecutive patients with an aortic valve prosthesis were evaluated with retrograde left ventricular catheterization. The prosthesis was successfully crossed, permitting hemodynamic and angiographic evaluation of function of the prosthetic valve, left ventricle and mitral valve in all 27 cases. No complications were encountered. In patients with active endocarditis or recent embolization, the retrograde technique was avoided when possible, and attempts were made to utilize other techniques for study. However, three such patients were evaluated with the retrograde technique without complication. Examination of pressure tracings and cineangiographic films suggested only minor interference with valve poppet movement induced by the catheter transversing the valve. In three cases, hemodynamic data were recorded with the catheter crossing the prosthesis at one time and a paraprosthetic valve defect at another time. Identical gradients were recorded. This series documents the safety and efficacy of the retrograde approach, which is proposed as an alternative to the transseptal technique and left ventricular puncture.

Angiocardiography↗
PubMed1978

Ondine's Curse: hemodynamic response to diaphragm pacing (electrophrenic respiration).

The hemodynamic response to diaphragm pacing was studied in eight patients with Ondine's Curse. It was shown that such pacing could lower the pulmonary artery pressure while correction of hypoxemia alone could not. It was demonstrated that on pacing, calculated pulmonary arteriolar resistance decreased and there was normalization of arterial blood gases. The mechanism for these changes was improved alveolar ventilation.

Adult↗
PubMed1978

Modification of intraaortic balloon catheter to permit introduction by cardiac catheterization techniques.

Intraaortic balloon counterpulsation has been widely applied for treatment of left ventricular pump failure and intractable angina. However, its use has been limited by the difficulty of balloon insertion in some patients and vascular complications in others. An AVCO intraaortic balloon was modified by the addition of a central lumen to allow pressure monitoring, injection of contrast medium and passage of a guide wire. The device was successfully used in 15 of 16 patients, including 4 of 5 in whom attempts to place a standard balloon catheter had failed. No significant vascular complications occurred in any patient. The modified balloon catheter appears to increase the efficacy and safety of insertion and allows immediate and continuous monitoring of arterial pressure.

Adult↗
PubMed1977

Altered hemoglobin-oxygen affinity with long-term propranolol therapy in patients with coronary artery disease.

Pharmacologic agents that alter hemoglobin affinity for oxygen may affect systemic or myocardial oxygen delivery. In vitro, and in normal man propranolol shifts the oxyhemoglobin equilibrium curve to the right, thus increasing the partial pressure of oxygen at which hemoglobin is 50% saturated (P50) and enhancing oxygen delivery. The effect of propranolol on hemoglobin P50 was evaluated in 12 patients with angina pectoris and documented coronary artery disease. Determinations were made during oral propranolol therapy (mean daily dose 152 mg) of at least 3 months' duration and after administration of propranolol had been discontinued for at least 4 days. Hemoglobin P50 and erythrocyte 2,3-diphosphoglycerate (DPG) were measured. Data in 12 patients were: the mean P50 after discontinuation of propranolol was 28.2 mm Hg+/-0.9 (standard error of the mean) and during propranolol therapy 31.7+/-0.7; P less than 0.001; red blood cell 2,3-DPG did not change to explain the increase in P50. This demonstrated shift could increase systemic oxygen delivery and thus benefit marginally perfused myocardium while sparing coronary flow. Propranolol, in addition to its negative chronotropic and inotropic effects, may increase tissue oxygen delivery in patients with the anginal syndrome.

Coronary Disease↗
PubMed1977

Angiographic evaluation of saphenous vein bypass grafts: artifactual "occlusion" caused by dual sources of flow.

Angiography after coronary bypass surgery has engendered conflicting reports regarding the effect of grafting on proximal lesions. Analysis of a series of postoperative arteriographic injections demonstrates that routine studies may produce artifactual "occlusion" caused by altered or competitive flow relations. High pressure contrast injection can reveal persistent stenotic lumens at sites of apparent complete occlusion. Thus, angiographic technical factors and not surgical sequelae may be responsible for the disparate reports on this subject.

Coronary Angiography↗
PubMed1977

Effects of orthostatic postural changes on myocardial oxygen demands.

The effects of orthostatic tilting were studied in 12 mongrel dogs anesthetized with sodium pentobarbital. Orthostasis produced significant decreases in cardiac output and left ventricular dimensions. Secondary decreases in coronary flow and myocardial oxygen consumption were also documented. These changes were attenuated when the animals were pretreated with propranolol. The upright posture may be of value in treatment of angina pectoris.

Animals↗
PubMed1977

Cardiac prostaglandin release during myocardial ischemia induced by atrial pacing in patients with coronary artery disease.

The relation between myocardial release of prostaglandin and myocardial ischemia was studied in 12 selected patients with multivessel coronary artery disease. These 12 were chosen for analysis because they experienced angina pectoris, ischemic electrocardiographic changes and decreased myocardial lactate uptake during atrial pacing. Simultaneous aortic and coronary sinus blood samples were obtained at rest, during angina and after recovery and were assayed for prostaglandins F, E and A with radioimmunoassay. Cardiac release of prostaglandin F was observed during angina in 11 of 12 patients. Aortic prostaglandin levels remained constant throught each study. During angina, the mean aortovenous difference (+/- standard error) was -0.30 +/- 0.04 ng/ml (P less than 0.001) for prostaglandin F and -0.10 +/- 0.03 ng/ml (Pless than 0.001) for prostaglandin E. There was no significant release of prostaglandin A. Blood samples were also drawn at subanginal heart rates in two patients. Prostaglandin F was released only during angina. In three control patients with a chest pain syndrome and normal coronary arteries, comparable atrial pacing produced no release of prostaglandin F, E or A. These results, together with the known vascular and metabolic actions of prostaglandins, suggest that these pharmacologically active compounds may also play a physiologic role in the cardiac response to ischemia in man.

Adult↗
PubMed1977

Single coronary artery from the right sinus of Valsalva: angiography, anatomy, and clinical significance.

A case of single coronary artery from the right sinus of Valsalva with a connecting branch passing between the aorta and right ventricular infundibulum is described. The anomaly was demonstrated at coronary arteriography and verified at surgery. This type of single coronary artery has been associated with sudden exertional death in young persons. The case prompted a review of the classification of single coronary artery with emphasis on clinical significance of the various subtypes and angiographic findings.

Angiography↗
PubMed1976

Risk of death related to coronary arteriography: role of left coronary arterial lesions.

Seven deaths occurred within 5 days after study in 800 consecutive patients undergoing arteriography. All seven patients had severe anginal symptoms at rest or with minimal exertion, and all had extensive coronary artery disease. Four had left main coronary artery disease, and three had hemodynamically equivalent lesions involving both the proximal left anterior descending and circumflex branches. It is postulated that these deaths are due to a stress imposed upon patients in unstable condition with a particularly extensive myocardial perfusion deficit.

Angina Pectoris↗
PubMed1976

Pentobarbital anesthesia: lack of effect on venous prostaglandins in dogs.

Venous prostaglandins A, E, and F were determined by radioimmunoassay in 10 dogs before and one hour after administration of sodium pentobarbital (35 mg/Kg, iv). In the conscious state, PGA was 0.34 + 0.04 ng/ml (mean +/- SE), PGE 0.20 + 0.01 ng/ml, and PGF 0.25 + 0.03 ng/ml. During pentobarbital anesthesia, these levels were unchanged (p greater than 0.05). Thus, pentobarbital anesthesia had no effect on peripheral venous prostaglandin levels.

Anesthesia↗
PubMed1976

Dual radionuclide study of myocardial infarction. Relationships between myocardial uptake of potassium-43, technetium-99m stannous pyrophosphate, regional myocardial blood flow and creatine phosphokinase depletion.

The dual radionuclide myocardial distributions of imaging agents potassium-43 (43K) and technetium-99m stannous pyrophosphate (99mTc-PYP) were studied in a 24-hour closed chest canine infarct preparation. In multiple myocardial biopsies in 20 dogs, tissue levels of both radionuclides were compared to either an index of tissue viability (myocardial creatine phosphokinase [CPK] depletion), or to estimates of regional myocardial blood flow as measured by the microsphere technique. Myocardial 43K uptake in the ischemic and infarcted zone correlated well with both CPK depletion (r = 0.73) and microsphere estimates of relative blood flow. The correlation with microspheres was excellent in the transmural sample (r = 0.93) as well as endocardial (r = 0.97) and epicardial (r = 0.86) portions. On the other hand, 99mTc-PYP myocardial uptake did not correlate with the extent of CPK depletion. Maximal uptake was frequently noted in border zones with only moderate CPK depletion, while lesser degrees of 99mTc-PYP uptake were noted in the central infarct zone where CPK activity was lowest. The relationship of 99mTc-PYP uptake to microsphere regional flow estimates demonstrated that 99mTc-PYP uptake was maximal at flows of 0.3 to 0.4 of normal. At lower flows, 99mTc-PYP uptake fell toward normal levels. A similar relationship was noted between the distributions of 99mTc-PYP and 43K. In relatively high flow border segments (larger than or equal to 0.80 of normal), abnormal 99mTc-PYP uptake of five to six times normal persisted. The transmural distribution of 99mTc-PYP demonstrated that in low flow regions 99mTc-PYP uptake was primarily epicardial, while in the higher flow ischemic periphery of the infarct endocardial uptake predominated. Thus, while there is a direct correlation between cationic 43K myocardial uptake and regional myocardial viability and blood flow, no such direct relationship exists for 99mTc-PYP. This is in part based on the necessity for delivery of the radioactive tracer to the infarct zone.

Animals↗