George R Nadzam

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BACKGROUND Multiple factors contribute to an improved defibrillation threshold of biphasic shocks. The leading-edge voltage of the second phase may be an important factor in reducing the defibrillation threshold. METHODS AND RESULTS We tested two experimental biphasic waveforms with large voltage changes at phase reversal. The phase 2 leading-edge voltage(More)
The effect of intermittent glucose administration on the circadian rhythm of body temperature was studied in rats to provide evidence of sugar addiction, withdrawal and relapse. Metabolic and behavioral phenomena were also observed. Biotelemetry transmitters recorded body temperature for the duration of the 4-week experiment. Rats were divided into an(More)
OBJECTIVES We sought to evaluate the safety and efficacy of higher energy synchronized cardioversion in patients with atrial fibrillation refractory to standard energy direct current (DC) cardioversion. BACKGROUND Standard external electrical cardioversion fails to restore sinus rhythm in 5% to 30% of patients with atrial fibrillation. METHODS Patients(More)
The purpose of this study was to develop a laboratory animal model of human shift work. Two methods of monitoring circadian rhythms in rats were employed: an activity wheel cage, where number of wheel revolutions (WR) were counted, and an internal radio transmitter, which recorded gross motor activity (GMA) and body temperature (BT). Rats were implanted(More)
Vasopressin-containing Long-Evans and vasopressin-deficient Brattleboro rats were maintained in individual cages while telemetered activity (AC) and body temperature (BT) data were collected. Rats were initially exposed to a 12 h/12-h light/dark cycle (photic zeitgeber) and were allowed ad-libitum access to food and water. Daily feeding, care, and handling(More)
Telemetered body temperature (BT), heart rate (HR), and activity (AC) data were collected in vasopressin-containing Long-Evans (LE) and vasopressin-deficient Brattleboro (DI) rats. The rats were exposed to a 12/12 h light/dark cycle under three conditions: 1) ad lib feeding throughout the 24-h cycle, 2) two scheduled-feeding periods during the diurnal(More)
Telemetered body temperature (BT), heart rate (HR), and motor activity (AC) data were collected in vasopressin-containing, Long-Evans (LE) and vasopressin-deficient, Brattleboro (DI) rats. In Experiment 1, the rats were initially exposed to a 12 h/12 h light/dark cycle under ad-libitum feeding and were then subjected to either a phase-advance or phase-delay(More)
Vasopressin-containing, Long-Evans (LE) rats and vasopressin-deficient, Brattleboro (DI) rats were monitored for activity and core body temperature via telemetry. Rats were exposed to a 12-12 light-dark cycle and allowed to habituate with ad lib access to food and water. The habituation period was followed by an experimental period of 23 h of(More)
BACKGROUND Pulmonary vein antral isolation (PVAI) is an effective treatment for atrial fibrillation and involves prolonged procedure and fluoroscopy times. This study assesses the impact of a comprehensive radiation safety program on patient and operator radiation exposure during PVAI. METHODS AND RESULTS We evaluated a comprehensive radiation safety(More)