The American journal of cardiology
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparative efficacy and tolerance of esmolol to propranolol for control of supraventricular tachyarrhythmia.
This multicenter, double-blind, randomized, parallel study compared the effectiveness and tolerance of intravenous esmolol with intravenous propranolol in patients with supraventricular tachyarrhythmia (heart rate [HR] greater than 120 beats/min). Efficacy was evaluated in 53 patients receiving esmolol and in 57 patients receiving propranolol. Patients randomized to esmolol received infusions of various doses of esmolol ranging from 50 to 300 micrograms/kg/min (each dose infused for 5 minutes) over a 30-minute titration period with intermittent placebo boluses of propranolol. ⋯ After discontinuation of study drugs, a more rapid reversal of the reduction in HR was observed in esmolol patients compared with those patients receiving propranolol. Adverse reactions were seen in 29 (45%) patients on esmolol and 11 (18%) patients on propranolol. The principle adverse reaction was hypotension, which was predominantly asymptomatic and found in 23 patients receiving esmolol and 4 receiving propranolol.(ABSTRACT TRUNCATED AT 250 WORDS)
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Randomized Controlled Trial Comparative Study Clinical Trial
Use of esmolol in hypertension after cardiac surgery.
Systolic hypertension, which is common soon after cardiac surgery, increases cardiac work and may threaten fresh vascular anastomoses. Because postoperative hypertension is often associated with elevated catecholamines and preoperative use of beta-blocking agents, esmolol, an ultrashort-acting beta-blocking agent, was compared with nitroprusside in a crossover study in this setting. Twelve patients, 18 to 28 hours after cardiac surgery (coronary artery bypass graft in 9, aortic valve replacement in 2 and valved aortic conduit with reimplantation of coronary arteries in 1 patient) received controlled infusions of esmolol (mean dosage 142 +/- 100 micrograms/kg/min, range 50 to 300 micrograms/kg/min) and nitroprusside (mean dose 1.6 +/- 1.3 micrograms/kg/min, range 0.5 to 2.75 micrograms/kg/min). ⋯ Systemic vascular resistance, unchanged by esmolol, was decreased significantly by nitroprusside. Oxygen saturation and Pao2, unchanged with esmolol, were both significantly reduced with nitroprusside. Thus, for hypertension early after cardiac surgery, esmolol is safe, effective and rapid and, compared with nitroprusside, results in less unwanted decrease in diastolic blood pressure and oxygen saturation, but there is more decrease in heart rate and cardiac index.
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Stressful surgical stimuli, such as endotracheal intubation, surgical incision, organ manipulation and emergence from anesthesia, elicit adrenergic responses that precipitate transient but intense increases in heart rate and blood pressure. Although this response is well tolerated in healthy patients, patients with ischemic heart disease are at significant risk of myocardial ischemia and infarction owing to the sudden increase in myocardial oxygen demand. Parenteral beta blockers are effective in blunting this adrenergic response, but the duration of action of these agents is long-lasting and the degree of beta blockade is often difficult to predict. ⋯ Clinical studies performed during the perioperative period reveal that esmolol is safe and effective in this setting. Esmolol has been shown to be safe and efficacious in patients in ASA classifications I through IV and patients undergoing carotid endarterectomy and coronary artery bypass surgery. The pharmacokinetic profile, rapid onset and elimination half-life make this agent particularly well suited to treat the very intense but transient adrenergic responses to surgical stress in patients undergoing cardiac and noncardiac surgery.
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Randomized Controlled Trial Comparative Study Clinical Trial
Comparative efficacy and safety of oral tocainide and quinidine for benign and potentially lethal ventricular arrhythmias.
The antiarrhythmic efficacy and safety of oral tocainide hydrochloride and quinidine sulfate were compared in a double-blind, 3-center, parallel trial involving 133 patients with benign and potentially lethal ventricular arrhythmias. Baseline demographic, etiologic, functional and ventricular arrhythmia data were not significantly different between the 2 groups. Two weeks of an initial placebo period were followed by 8 weeks of active drug treatment, concluding with 4 weeks of washout. ⋯ Quinidine caused a prolongation in the QT interval (0.03 second); tocainide caused a slight reduction (0.01 second). No important changes in vital signs or laboratory measurements were observed in left ventricular ejection fraction when measured. Thus, tocainide, the new oral analog of lidocaine, appears to be as safe as quinidine but is slightly less effective in suppressing ventricular arrhythmias.