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Biomedical subjects

J Mehta

Publications and source records attributed to J Mehta.

At least 361 records · Page 20Linked to original sources

Electrocardiographic and vectorcardiographic abnormalities in Fabry's disease.

Fabry's disease has been reported to be associated with ECG abnormalities. Thirty-two patients with this disease followed in the University of Minnesota had ECG's and 15 had VCG's. An abonrmal rhythm was observed in two patients on initial examination and four more developed abnormal rhythm on follow-up examinations. A short PR interval (120 msec. or less) was seen in five patients. Thirteen others had a PR interval that was less than 140 msec. Conduction abnormalities involving the A-V node or His bundle or its branches were present in 22 per cent of the patients, most frequently the intraventricular conduction defects progressing to the right bundle branch block. Atrial or ventricular enlargement was seen in 60 per cent of the patients, left ventricular hypertrophy being the most common. ST-T changes with or without chamber enlargement were seen in 10 patients. One patient had an anterior myocardial infarction pattern on his ECG. Hemizygosity was found to be associated with significantly more abnormalities than heterozygosity. The severity of conduction defects also increased with the duration of the disease process. Vectorcardiography in this study did not provide significant additional information other than that observed on the ECG alone. Since the pathology usually reveals myocardial fibers, conduction system, and blood vessels infiltrated with glycosphingolipid, it is believed that lipid infiltration is responsible for conduction defects, chanber enlargement, and other abnormalities. Although Fabry's disease is rate, it may be amenable to therapy; therefore, recognition of cardiac involvement is important.

Adolescent↗

Hemodynamic effects of labetalol, an alpha and beta adrenergic blocking agent, in hypertensive subjects.

Labetalol was administered to six hypertensive subjects in increasing doses for seven days. A decrease in both supine and standing arterial pressure and heart rate was observed with no change in cardiac output and few side effects. Exercise tolerance was unaltered by the drug, but the heart rate and arterial pressure response to exercise were significantly blunted. The infusion rate of isoproterenol required to produce tachycardia was increased sevenfold by 800 mg/day labetalol and tenfold by 1600 mg/day. More than twice the control dose of phenylephrine was required during labetalol therapy to produce a rise in diastolic arterial pressure reflex tachycardia to amyl nitrite-induced hypotension was attenuated. These studies indingina pectoris.

Adrenergic alpha-Antagonists↗

Aortic regurgitation associated with ventricular septal defect. Echocardiographic and hemodynamic observations.

Ventricular septal defect is sometimes associated with aortic regurgitation. In this report, an echocardiogram demonstrating dramatic prolapse of the noncoronary cusp into the left ventricular outflow tract and ventricular septal defect in a patient with Down's syndrome and ventricular septal defect, confirmed by angiographic studies, is presented. The echocardiogram supports the concept of anatomic lack of support of the aortic ring due to a deficient septum and hemodynamically significant flow of blood to the right ventricle through the ventricular septal defect, resulting in trauma to aortic cusps and prolapse.

Adult↗

Vectorcardiographic, electrocardiographic, and angiographic correlations in apparently isolated inferior wall myocardial infarction.

Twenty-six patients with ECG evidence of localized inferior myocardial infarction and poor ejection fraction (less than 50 per cent) were compared with 26 patients with similar ECG's, but with normal ejection fraction (over 50 per cent). The poor ejection fraction group had significantly more frequent and more severe disease in left anterior descending artery and a higher incidence of triple coronary obstruction than the normal ejection fraction group. The poor ejection fraction group had a significantly greater incidence of ventricular asynergy in the anterior and apical segments of left ventricle. Vectorcardiography was available in 35 of the 52 patients studied and frequently supplied diagnostic information not available in the scalar ECG's. Of 18 patients with scalar ECG patterns of isols, vectorcardiography identified five cases with anterior infarction, three with left ventricular hypertrophy, and one with left anterior hemiblock. Vectorcardiography is a valuable supplementary tool in the clinical assessment of patients with apparently isolated inferior infarction. When extensive coronary and poor ventricular function exist, VCG clues may be expected in about half the patients.

Angiocardiography↗

Pituitary-testicular axis in patients on lithium therapy.

Plasma follicle-stimulating hormone (FSH), luteinizing hormone (LH), and testosterone levels were studied in 10 patients undergoing lithium therapy. Testosterone levels were below the normal range in 7 of the 10 patients. FSH levels were high in two patients and LH levels were high in one. The effects of lithium on the pituitary-testicular axis are discussed.

Adult↗

Anterior conduction delay: a possible cause for prominent anterior QRS forces.

Prominently anterior QRS forces often present a diagnostic dilemma. Frequently, right ventricular forces may be eliminated on clinical grounds and dorsal infarction is therefore suspected, especially in a clinical setting of coronary artery disease. In five such patients studied angiographically, the coronary disease was concentrated in the left anterior descending artery and the ventricular dysfunction confined to the anterior wall of the left ventricle. In a sixth case, the prominent anterior forces were observed intermittently together with left anterior hemiblock. These observations, in addition to serial studies following surgery, strongly suggest that the mechanism for prominent anterior QRS forces in these cases is conduction delay in an anterior division of the left bundle branch system.

Adult↗

Pacemaker Wenckebach phenomenon due to antiarrhythmic drug toxicity.

Two patients with intractable ventricular arrhythmia were managed with ventricular pacing and antiarrhythmic drugs. Toxic levels of these drugs results in unusual conduction disturbances at the level of Purkinje ventricular junction which caused pacemaker Wenckebach phenomenon and marked QRS prolongation. Sodium bicarbonate and sodium lactate infusion improved the conduction velocity probably by hyperpolarizing the membrane and reversed the conduction disturbance.

Aged↗

Reappraisal of the role of the diabetic state in coronary artery disease.

Clinical and coronary arteriographic findings were evaluated in patients with angina pectoris who were considered not to have diabetes mellitus or to have chemical or clinical diabetes. Each of the three groups consisted of 100 consecutive referred patients. Neither the age of the patients nor duration of symptoms differed significantly among the groups. Hypertension, gout, and peripheral vascular disease were more frequent in the patients with clinical diabetes. There was no difference in serum cholesterol concentration among the groups, but plasma triglyceride levels and the frequency of type 4 hyperlipoproteinemia were significantly higher (p less than 0.01) in the chemical and clinical diabetic groups than in the nondiabetic patients. Coronary arteriographic observations indicated that the severity of the coronary arterial disease was greater in both diabetic groups than in nondiabetic patients. The difference in the coronary scores among the three groups of patients interacts to some extent with the triglyceride level, since a high score in the diabetic groups was noted only in the presence of an elevated tryglyceride concentration. The results indicate that the increased severity of coronary arterial disease in diabetic patients is not attributable to age, duration of symptoms, hypertension, type -4 hyperlipoproteinemia, or apparent severity of the glucose intolerance.

Adult↗

Medical-surgical aspects of left main coronary artery disease.

Disease of the left main coronary artery compromises circulation to the major part of the left ventricle and thus threatens massive myocardial infarction and sudden death. Cardiac catheterization and coronary bypass surgery, in previous reports, have been associated with high mortality and morbidity rates. We report 50 patients with over 50 per cent narrowing of the left main coronary artery. The clinical pattern in these patients was variable and a left main coronary artery lesion could not be predicted before coronary angiography. There was only one death during cardiac catheterization. One patient died while waiting for elective surgery. Coronary bypass surgery was performed in 42 patients; one died during surgery. Forty-one patients are alive at 2 to 39 months follow-up (mean, 19 months). Thirty-six patients are asymptomatic or have minimal symptoms. Compared to the prognosis in patients with left main coronary artery stenosis treated medically, coronary bypass surgery performed on urgent basis offers a much better prognosis. Both coronary angiography and bypass surgery can be performed in these patients with a very low risk.

Adult↗

Preoperative coronary angiographic prediction of bypass flow and short-term patency.

A quantitative preoperative coronary angiographic index was defined in 148 patients undergoing coronary revascularization. Each diseased vessel was scored 0-3, for both diameter and quality of run-off. The sum of the scores for diameter and run-off constituted the numerical index for the diseased vessel. Correlations between the index and graft flow measured by electromagnetic flow meter at surgery were established in 259 bypassed vessels. The highest scores (5-6) were associated with higher flows, and the lower scores (0-4) with the lower flows (P less than 0.005). Repeat angiography performed 2 wk postoperatively in 110 patients demonstrated 174 graft patencies and 15 graft closures. Mean flow in open grafts was 82 +/- 41 ml/mn vs. 60 +/- 23ml/mn in closed grafts (P less than 0.005). It is concluded that graft flow is predictable from preoperative Coronary Angiographic Index and that higher flow and index scores are more likely to be associated with graft patency than low flows and index scores.

Angina Pectoris↗

Congenital aneurysm of the left ventricle associated with supravalvular aortic stenosis and aneurysm of the left main coronary artery: case report and review of the literature.

We report a unique case of a 33 year old female with congenital aneurysm of the left ventricular apex associated with an aneurysm of the left main coronary artery and surgically repaired supravalvular aortic stenosis. The congenital aneurysm of the left ventricular apex was not associated with a midline thoraco-abdominal defect, as reported in the medical literature. The patient survived two episodes of thrombo-embolism and is well after 10 years of medical follow-up.

Adult↗

A new catheter for percutaneous transfemoral right heart catheterization.

A new catheter for percutaneous transfemoral right heart catheterization is described. The catheter can also be used for pulmonary angiography and pulmonary wedgepressure recording. Because of the speed and efficiency with which this catheter may be used, we suggested a trial by physicians involved in right heart catheterization pulmonary angiography.

Cardiac Catheterization↗