[Intermittent bradycardia-dependent bundle branch block during sevoflurane and remifentanil anesthesia]

Cardiac arrhythmia and bradycardia occasionally occur from the effect of inhaled anesthetic agent and opioid on cardiac conduction. We experienced a case of intermittent bradycardia-dependent bundle branch block (IBDBBB) during sevoflurane and remifentanil anesthesia. A 17-year-old woman suffering from recurrent left ottitis media was scheduled for tympanoplasty under general anesthesia. Her preoperative electrocardiogram (ECG) revealed normal sinus rhythm at heart rate (HR) of 48 beats x min(-1). Her tracheal was intubated following anesthesia induction with propofol and vecuronium, and anesthesia was maintained using inhalation of 40% oxygen with air and 1.5-2.0% sevoflurane, and continuous venous infusion of remifentanil at a rate of 0.15 microg x kg(-1) min(-1). Two hours 20 minutes after starting operation, the P-P interval was constant but the waveforms of low and broad QRS complexes appeared intermittently on the ECG monitor. The blood pressure remained stable at 95/55 mmHg and the HR decreased to 46 beats x min(-1). The waveform of pulse oxymetric oxygen saturation (Spo2) did not change. We diagnosed the ECG pattern as IBDBBB. After intravenous injection of atropine 0.5 mg, the waveforms of QRS complexes recovered to normal sinus rhythm at HR 90 beats x min(-1). Sevoflurane and remifentanil in adolescence could induce ventricular conduction disturbance and result in IBDBBB. Atropine could be effective for IBDBBB induced by sevoflurane and remifentanil.