Objective: To describe the case of an adult patient with swallow syncope after bypass surgery, possibly related to hypoxia.
Design: Case report.
Setting: University hospital, medical-cardiologic intensive care unit.
Patient: A 67-yr-old patient after second aortocoronary bypass operation for unstable angina.
Main results: After the patient managed to extubate himself, he was in a borderline respiratory condition with an oxygen mask. When drinking for the first time after extubation, asystole was observed coincidentally with interruption of oxygen insufflation. During the next days, similar events occurred during food ingestion or when drinking liquids after a fall of oxygen saturation. The bradyarrhythmia was readily reversible on administration of atropine and ventricular backup pacing via temporary pacing wires. After normalization of gas exchange, no more episodes of swallowing-associated asystole were observed and the patient was discharged without a permanent pacemaker. There was no esophageal or gastrointestinal disease. Pre- and postoperative PR and QRS durations were normal.
Conclusion: Extrinsic and transient mechanisms, rather than intrinsic conduction system disease, seem to have been operative in this case. It is suggested that hypoxia reinforced the vagal pharyngocardiac reflex as described in pediatric patients.