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Biomedical subjects

F I Marcus

Publications and source records attributed to F I Marcus.

At least 109 records · Page 6Linked to original sources
PubMed1983

Drug interactions with amiodarone.

There are a number of important drug interactions with amiodarone. This agent appears to have a marked effect on the kinetics of some commonly used cardiovascular drugs, such as warfarin, digoxin, quinidine, and procainamide, and has dynamic interactions with others, such as the beta blockers and some calcium antagonists. Bleeding has been reported, apparently caused by a potentiation of the anticoagulant effect of warfarin by amiodarone. Torsades de pointes has been observed when quinidine, propafenone, or mexiletine is given together with amiodarone. Furthermore, amiodarone may interact with beta-blocking agents and some of the calcium antagonists to produce symptomatic sinus bradycardia and sinus arrest, especially in a latent or overt sick sinus syndrome. During surgery, amiodarone may induce hypotension and an atropine-resistant bradycardia, possibly by interacting with anesthetic agents. A knowledge of the time of onset, extent, duration, and possible mechanisms of the interactions of amiodarone with other cardioactive drugs is still incomplete, but further studies are of great therapeutic importance.

Adrenergic beta-Antagonists↗
PubMed1983

Clinical characteristics and results of noninvasive tests in 60 diabetic patients after acute myocardial infarction.

Diabetic patients who survive myocardial infarction have more similarities than differences when compared with nondiabetic patients. Silent myocardial infarctions were not more common in the diabetic population. The higher percentage of women among diabetic patients with infarction has been well recognized. Of the primary risk factors, hypertension was more common in diabetic patients. Clearly, a history of ischemic heart disease was more common in diabetic patients. The course in the coronary care unit was similar for both the diabetic and nondiabetic patient groups. Likewise, there were no striking differences in left ventricular ejection fractions or results of 24-hour Holter monitoring between the groups. The fact that a higher percentage of diabetic patients were excluded from taking the limited activity treadmill test, primarily because of angina after infarction, may account for the observation that the percent of patients with an ischemic response to exercise and the percent with exercise-induced ventricular ectopy did not differ between diabetic and nondiabetic groups.

Coronary Care Units↗
PubMed1982

Treatment of life-threatening digitalis intoxication with digoxin-specific Fab antibody fragments: experience in 26 cases.

Purified Fab fragments of digoxin-specific antibodies obtained from sheep were used to treat 26 patients with advanced, life-threatening digoxin (23 cases) or digitoxin (3 cases) toxicity. These patients had advanced cardiac arrhythmias, and in some cases hyperkalemia, which were resistant to conventional treatment. All patients had an initial favorable response to doses of Fab fragments calculated (in most cases) to be equivalent, on a molar basis, to the amount of cardiac glycoside in the patient's body. In four patients treated after prolonged hypotension and low cardiac output, death ensued from cerebral or myocardial hypoperfusion. In one case the available Fab fragment supply was inadequate to reverse a massive suicidal ingestion of digoxin, and the patient died after recurrent ventricular arrhythmias. In the remaining 21 patients, cardiac rhythm disturbances and hyperkalemia were rapidly reversed, and full recovery ensued. There were no adverse reactions to the treatment. We conclude that the use of purified digoxin-specific Fab fragments is a safe and effective means to reverse advanced, life-threatening digitalis intoxication.

Adolescent↗
PubMed1982

Effect of quinidine on the heart rate and blood pressure response to treadmill exercise.

The effect of quinidine on the heart rate and blood pressure response to treadmill exercise was evaluated in 17 normal subjects. Quinidine significantly increased the heart rate at rest and at low levels of exercise. Quinidine had no significant effect on the systolic blood pressure response to any work load. However, quinidine significantly decreased the systolic blood pressure at all exercising heart rates, compared to control, in 15 of the 17 subjects. The magnitude of the decrease in systolic pressure ranged from 1 to 22 mm Hg, with a mean of 10 mm Hg.

Adrenergic alpha-Antagonists↗
PubMed1982

Clinical correlations in patients with acute myocardial infarction and left ventricular thrombus detected by two-dimensional echocardiography.

Eleven of forty-nine patients with acute myocardial infarction had left ventricular thrombus identified by two-dimensional echocardiography. The patients with thrombi had a greater incidence of transmural infarction, high-grade ventricular ectopy on ambulatory monitoring and lower radionuclide ejection fractions than the patients without thrombi. Most of the patients were receiving full-dose heparin and/or warfarin anticoagulation from the time of admission to the hospital. Thus the thrombi either developed prior to hospital admission or developed during anticoagulation therapy. Two patients with thrombi had peripheral emboli complicating their infarction. One of these patients was undergoing anticoagulation at the time of his embolus.

Aged↗
PubMed1982

Right ventricular dysplasia: a report of 24 adult cases.

Right ventricular dysplasia is characterized by an abnormality in the development of part of the right ventricular musculature. Patients with right ventricular dysplasia may present with ventricular tachycardia, supraventricular arrhythmias, right-heart failure or asymptomatic cardiomegaly. Twenty-two adult patients with right ventricular dysplasia who had recurrent ventricular tachycardia were seen during a 7-year period. The male/female ratio was 2.7:1. The mean age at the time of hospitalization was 39 years. All but one of the patients had ventricular tachycardia of a left bundle branch block configuration. With few exceptions, the T waves were inverted over the right precordial leads. The heart was usually enlarged and the pulmonary vasculature was usually normal. In six patients who had two-dimensional echocardiograms, all showed increased right ventricular diastolic dimensions. All patients had right ventricular angiography; the diagnosis of right ventricular dysplasia was substantiated during surgery in 12 patients and at autopsy in another. Two other patients who did not have arrhythmias had right ventricular dysplasia diagnosed by right- and left-heart angiography. Our unique experience, when combined with a literature review of 34 adult cases, permits a composite clinical profile of this condition in the adult.

Adolescent↗
PubMed1982

[Arrhythmogenic right ventricular dysplasia and Uhl's disease].

Ventricular tachycardia with left bundle branch block appearance in adults without coronary artery disease may be due to arrhythmogenic right ventricular dysplasia. This condition forms part of a spectrum with the complete form of Uhl's anomaly at one end and arrhythmogenic right ventricular dysplasia at the other. Both conditions have similar histological appearances representing the same congenital defect but the macroscopic appearances are quite different. Arrhythmogenic right ventricular dysplasia seems to be a slowly progressive condition with one or more localisations in the right ventricle where the myocardium is replaced by adipose tissue with progression of lesions from the epicardium towards the endocardium. The subepicardial layers resemble a plexiform structure of partially degenerated myocardial fibres within fibro-adipose tissue. These fibres may be the site of slowing of activation and the anatomical basis of intraventricular reentry phenomena. A similar appearance is also found in UHl's anomaly, but the severe dilatation of the ventricle and almost complete absence of muscle fibres only leaves a few zones with surviving, partially degenerated myocardial fibres. Clinically, a cardiothoracic index of over 0.60 is more common in Uhl's anomaly whilst arrhythmogenic right ventricular dysplasia is usually associated with a normal cardiac silhouette or only slight cardiomegaly. The differential diagnosis is important if surgery is being considered. An appropriate technique must be chosen to avoid supraventricular arrhythmias which can lethal in patients with Uhl's anomaly.

Adolescent↗
PubMed1981

Effect of intravenous metoprolol on reversible obstructive airways disease.

We gave increasing doses of metoprolol intravenously to seven subjects with stable chronic obstructive pulmonary disease (COPD) who were also receiving their usual bronchodilators. Six of the seven tolerated up to 0.2mg/kg metoprolol without adverse effects, although there were declines in forced expiratory volume in 1 sec (FEV1). At 0.15 mg/kg mean FEV1 fell 12% (p less than 0.025), and at 0.2 mg/kg mean decline in FEV1 was 15% (p less than 0.01). These findings suggest that 0.2 mg/kg metoprolol may be given intravenously to most patients with COPD in addition to previously administered bronchodilators without precipitating clinically significant adverse effects. Any side effects that develop can be reversed by beta agonists.

Adult↗
PubMed1980

Efficacy, plasma concentrations and adverse effects of a new sustained release procainamide preparation.

To assess the efficacy, plasma drug concentrations and adverse effects of a new sustained release preparation of procainamide, 33 patients with heart disease were studied in an acute dose-ranging protocol and a chronic treatment protocol. Patients initially received a daily dose of 3 g of sustained release procainamide; this dose was increased by 1.5 g daily until ventricular premature depolarizations were suppressed by 75 percent or more, adverse drug effects occurred or a total daily dose of 7.5 g of sustained-release procainamide was reached. Twenty-five patients (76 percent) had at least a 75 percent reduction (range 75 to 100percent [mean +/- standard deviation 91 +/- 8.2]) in ventricular permature depolarization frequency at a dosage of 4.8 +/- 1.46 g/day (range 3.0 to 7.5). Despite the 8 hour dosing interval, the variation between maximal and minimal plasma procainamide and N-acetylprocainamide concentrations under steady state conditions was very small. Mean maximal procainamide and N-acetylprocainamide plasma concentrations were 10.4 +/- 6.02 and 12.0 +/- 7.40 micrograms/ml, respectively. The respective mean minimal concentrations were 6.8 +/- 4.50 and 8.7 +/- 5.99 micrograms/ml. In nine patients (27 percent) treatment with sustained release procainamide resulted in conversion of the antinuclear antibody test from negative to positive. Adverse drug effects occurred in 17 (52 percent) of the subjects. In general, adverse effects were minor and abated within 24 hours after administration of the drug was stopped. One patient had the procainamide-induced systemic lupus erythematosus-like syndrome.

Acecainide↗
PubMed1980

Kinetic evaluation of the propranolol-quinidine combination.

The kinetics of quinidine and propranolol, administered singly and in combination, were evaluated in 5 healthy subjects. The orally administered doses resulted in plasma concentrations within the therapeutic range. For each drug the average steady-state plasma concentration, maximal plasma concentration, and time of maximum plasma concentration were not altered by the presence of the other drugs. This study shows no kinetic interaction between quinidine and propranolol in normal subjects.

Adult↗