850 REM Sleep and ST Deviation in Acute Myocardial Infarction

Abstract

Introduction Sleep stage architecture and amount of REM sleep have been associated with mortality and clinical recovery, without clear etiology. Patients recovering from critical illness frequently experience sleep disturbances, episodic arrhythmogenesis, EKG changes. This case aims to add to current field of study and describes an unusual pattern of sleep stage dependent, hypoxia independent, ST segment variation, which may benefit from further exploration and utilization of polysmongoraphy (PSG) in the immediate post acute MI period. Report of case(s) 46 year old female with history of smoking, obesity, and diabetes presented for a sleep medicine evaluation, four days following a hospitalization for non ST elevation myocardial infarction (NSTEMI) and percutaneous coronary intervention. Her split night PSG data revealed severe obstructive sleep apnea (OSA) with apnea hypopnia index (AHI) of 131. Patient did not report acute cardiac symptoms during overnight sleep evaluation. On close observation of PSG data, the patient had grossly evident baseline ST segment depression during wake period. The ST depression persisted through stages 1 and 2 with unchanged morphology. During Stage 3, the ST segment showed progressive elevation to near the isoelectric line. During REM sleep without positive airway pressure (PAP), ST segment was noted at or near isoelectric line, even in the setting of hypoxia with saturation (Sao2) of 75%. During REM Sleep with PAP, the ST segment remained at the isoelectric line, and returning to baseline depression during wake phase while on BiPAP. Conclusion Residual ST segment deviation, and its resolution, are strong predictors of prognosis in patients with MI. Prior studies focused on hypoxic tolerance and sleep disordered breathing, with limited attention on specific sleep stage evaluation. REM sleep has been described as potentially having restorative effect on ischemic myocardium. Additionally, the transition period from non REM to REM sleep was reported to provide potential for myocardial restoration. PSG with cardiac monitoring remains a unique tool in further assessment of a possible association. This case aims to bring attention to the potential association of EKG ST segment variation with sleep stages, especially REM and S3, independent of hypoxia. Support (if any):