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The study aims to determine whether amiodarone is superior to sotalol and whether both are superior to placebo in maintaining sinus rhythm in patients with persistent atrial fibrillation. The results revealed that amiodarone and sotalol are equally efficacious in converting atrial fibrillation to sinus rhythm.

Amiodarone may not prevent sudden death or prolong life in patients with heart failure and arrythmias. Amiodarone is a drug that causes dilation of blood vessels in the heart and prevents irregular heart beats, or arrythmias. Doctors assigned 336 patients to receive amiodarone and 338 to receive a placebo to determine the effect of the drug on longterm survival. Amiodarone did not have a significant effect on survival. During the study 274 patients died including 131 (39%) patients taking amiodarone and 143 (42%) taking a placebo. Among patients taking amiodarone, 64 (49%) suffered a sudden death compared to 75 (52%) of those patients taking a placebo. Amiodarone did have some beneficial effects. After two weeks of therapy, the patients taking amiodarone had a significantly lower heart rate averaging 70 beats/minute. In addition, the average frequency of irregular heart beats decreased from about 254 per hour to 66 per hour at two weeks to 44 per hour after three months.

Syncope is a short-lived spell of unconsciousness that results from inadequate blood supply to the brain. This can result from a variety of causes, one of which is a hypersensitivity of the homeostatic reflex mechanisms, which maintain constancy of arterial blood pressure: pressure sensors in the carotid sinus (a segment of the carotid artery) which lower blood pressure when it rises beyond acceptable limits engage blood pressure-lowering mechanisms before they are needed, causing hypotension (low blood pressure), bradycardia (low heart rate) and fainting. One cause of this hypersensitivity may be pathological conditions, such as malignant tumors affecting the head and neck. Treatment for carotid sinus hypersensitivity can involve the use of an implanted pacemaker, which prevents the bradycardia, or drug treatment, which may prevent both the bradycardia and hypotension (although most attempts have been disappointing to date). A case is reported of a 52-year-old man who was hospitalized for investigation of repeated syncopal episodes. The patient had undergone removal of the larynx and extensive surgery of the neck as treatment for a malignant laryngeal tumor five months previous. Physical examination showed a tender, firm mass in the neck region; computed tomography (CT) scans revealed extensive tumor infiltration from the jaw region down into the sheath surrounding the carotid artery. A temporary cardiac pacemaker was installed, and the beta adrenergic blocking agent (beta blocker) propranolol was administered orally four times daily. Within two days, the syncope was brought under control, and the pacemaker removed with no recurrence of hypotension or bradycardia. The greatly improved condition of the patient allowed him to be discharged from the cardiac care unit to seek radiation therapy for the cervical mass. The mechanism by which propranolol reversed the carotid sinus hypersensitivity-induced syncope is unknown; pharmacological blockade of the reflex controlling blood pressure is the most likely explanation. (Consumer Summary produced by Reliance Medical Information, Inc.)

The platelet aggregate ratio has been found to be decreased in some patients with vascular diseases suggesting the presence of increased circulating platelet aggregates. It has also been reported that hypercholesterolaemia is associated with an enhanced response of platelets to aggregating agents in platelet-rich plasma. The primary purpose of this investigation was to determine correlation of the platelet aggregate ratio with the serum cholesterol concentration of men with vascular diseases. For 52 men referred because of known or suspected coronary artery disease, cerebrovascular disease, or venous thromboembolism, the correlation coefficient of 0·06 suggested that the serum cholesterol concentration within the range observed (135-360 mg/dl) was not a factor influencing the platelet aggregate ratio. There was not a statistically significant difference between the mean platelet aggregate ratios or the mean serum cholesterol concentrations of the 21 non-smokers and the 31 smokers studied. A correlation coefficient of 0·03 between the platelet aggregate ratio and age of the patient suggested that the platelet aggregate ratio was independent of age in men with occlusive vascular diseases. [ABSTRACT FROM PUBLISHER]

The Sotalol-Amiodarone Fibrillation Efficacy Trial (SAFE-T) is a randomized, double-blind, multicenter, placebo-controlled trial in which the effects of sotalol and amiodarone in maintaining stability of sinus rhythm are being examined in patients with persistent atrial fibrillation at 20 Veterans Affairs medical centers. The time to the occurrence of atrial fibrillation or flutter in patients with atrial fibrillation converted to sinus rhythm is the primary outcome measure, with a number of parameters as secondary end points. SAFE-T had randomized 665 patients when enrollment terminated on October 31, 2001. Follow-up of patients continued until October 31, 2002, for a maximum period of 54 months and a minimum period of 12 months for all patients. [Copyright &y& Elsevier]