In patients with successful RF ablation, the frequency of subsequent events was reduced compared with the 2 preceding years. However, recurrence of IART in patients who showed clinical improvement was frequent, and often revealed the presence of new IART configurations.

To study the effects of airway obstruction (AWO) and arousal on coronary blood flow, mean arterial pressure (MAP), and heart rate, pigs were chronically instrumented with arterial catheters, Doppler flow probes on the left circumflex coronary artery, and electrodes for determination of sleep stages. A modified tracheostomy tube was placed in the trachea to obstruct the upper airway during sleep sessions. In control studies, during non-rapid-eye-movement (NREM) sleep, MAP was 84 +/- 2 mmHg before AWO and increased by 5 +/- 2 mmHg on arousal. MAP was lower during rapid-eye-movement (REM) sleep (62 +/- 2 mmHg), and the increase on arousal was fourfold greater (22 +/- 2 mmHg). Heart rate was similar in both sleep stages (NREM: 120 +/- 4 beats/min; REM: 124 +/- 5 beats/min) and increased significantly on arousal (NREM: 12 +/- 2 beats/min; REM: 18 +/- 1 beats/min). Coronary blood flow was similar during both stages (NREM: 43 +/- 4 ml/min; REM: 46 +/- 8 ml/min) and increased by 12-15% on arousal. Coronary vascular resistance index increased significantly by 24% on arousal from AWO during REM sleep. All increases and decreases were significant at P < 0.05. Receptor blockade studies were performed to assess alpha-adrenergic receptor involvement.

No abstract

This new system may ultimately assist in mapping simple or complex atrial arrhythmias during cardiac catheterization.