REVERSAL OF SINUS ARREST AND ATRIOVENTRICULAR-CONDUCTION BLOCK IN PATIENTS WITH SLEEP-APNEA DURING NASAL CONTINUOUS POSITIVE AIRWAY PRESSURE

Sinus arrest and atrioventricular (AV) block have been demonstrated in as much as 30% of patients with sleep apnea (SA). The reversal of heart block after tracheostomy has been shown. Nasal continuous positive airway pressure (nCPAP) now is widely used as the treatment of SA, but little data are available on the effect of nCPAP on heart block in patients with SA. During a 17-mo period 239 patients were found to have SA in an ambulatory study. Heart block was identified in 17 (16 male, one female) of these patients. Standard polysomnography and two-channel long-term ECG before and during nCPAP therapy were performed in order to assess the effect of nCPAP on SA and heart block. Mean age of the 17 patients was 50.7 yr (range, 27 to 78 yr), mean respiratory disturbance index (RDI) was 90/h (SD +/- 36.1) before nCPAP and 6/h (SD +/- 6.2) on the second treatment night. The number of episodes of heart block during sleep decreased significantly (p < 0.001) from 1,575 before therapy to 165 during nCPAP. In 12 patients (70.6%) heart block was totally prevented by nCPAP. In another three patients, there was a 71 to 97% reduction in the number of episodes of heart block on the second treatment night, and in two of them a complete reversal occurred thereafter. Two patients exhibited an increase in block frequency during nCPAP, which was reversed after 4 wk of nCPAP in one but persisted in the other. Clusters of Sinus arrest and second-degree AV block, which were identified during daytime in two patients while they reported to have fallen asleep, were not present after the initiation of nCPAP. The reduction of heart block using nCPAP is comparable to that achieved by tracheostomy However, long-term ECG should be reassessed during therapy, as significant blocks may persist despite a normalization of RDI. In our opinion a cardiac pacemaker should be implanted if heart block is not reduced substantially during nCPAP or if there is poor nCPAP compliance.