Nocturnal hypoxia and the success rate of standard atrial fibrillation treatment: a case report

INTRODUCTION: Sleep apnea-hypopnea syndrome (SAHS) is one of the extracardiac reasons of atrial fibrillation (AF), and the prevalence of AF is high in SAHS-diagnosed patients. Nocturnal hypoxemia is associated with AF, pulmonary hypertension, and nocturnal death. The rate of AF recurrence is high in untreated SAHS-diagnosed patients after cardioversion (CV). In this study, we present a patient whose SAHS was diagnosed with an apnea test performed in the intensive care unit (ICU) and who did not develop recurrent AF after the administration of standard AF treatment and bi-level positive airway pressure (BiPAP). CASE PRESENTATION: A 57-year-old male hypertensive Caucasian patient who was on medical treatment for 1.5 months for non-organic AF was admitted to the ICU because of high-ventricular response AF (170 per minute), and sinus rhythm was maintained during the CV that was performed two times every second day. The results of the apnea test performed in the ICU on the same night after the second CV were as follows: apnea-hypopnea index (AHI) of 71 per hour, minimum peripheral oxygen saturation (SpO(2)) of 67%, and desaturation period (SpO(2) of less than 90%) of 28 minutes. The patient was discharged with medical treatment and nocturnal BiPAP treatment. The results of the apnea test performed under BiPAP on the sixth month were as follows: AHI of 1 per hour, desaturation period of 1 minute, and minimum SpO(2) of 87%. No recurrent AF developed in the patient, and his medical treatment was reduced within 6 months. After gastric bypass surgery on the 12th month, nocturnal hypoxia and AF did not re-occur. Thus, BiPAP and medical treatments were ended. CONCLUSIONS: SAHS can be diagnosed by performing an apnea test in the ICU. SAHS should be investigated in patients developing recurrent AF after CV. Recovery of nocturnal hypoxia may increase the success rate of standard AF treatment.