Perioperative arrhythmia associated with aortic valve stenosis.

Peri-operative arrhythmia is one of the major complications in anaesthesia for valve replacement surgery in patients with aortic stenosis. In this retrospective study, 58 patients with sinus rhythm were investigated from induction of anaesthesia until arrival at the recovery room by close haemodynamic monitoring and Holter ECG recording. After cardiopulmonary bypass (CPB), they received either lidocaine (L, n = 35) or mexiletine (M, n = 23) via infusion for 24 hours. Pre-bypass incidence was 14% for supraventricular (SPBs) and 19% for ventricular serious arrhythmia (VPBs), i.e. high-grade forms which indicate possible deterioration and may require therapy (for all arrhythmia, incidences were 45 resp. 28%). VPBs was independently related to impaired left ventricular function (11 patients) and preoperative digitalis therapy (20 patients) but not to severity of stenosis, serum concentration of potassium (between 3.3 and 5.2 meq/l), or any other clinical parameters. Post-bypass incidence was SPBs 11% and VPBs 33%, the latter representing a significant increase compared to the first period (p < 0.03)--(all arrhythmia: 26 resp. 40%). VPBs was related to the need for multiple therapy including catecholamines and antiarrhythmic agents other than L or M, but no longer to preoperative parameters nor duration of intraoperative ischaemia. Incidences of arrhythmia for L and M were identical. While in these patients digitalis therapy may account for arrhythmia also in general anaesthesia, in valve replacement there is a post-bypass increase in VPBs which is not fully explained. Since the incidence is 33% in spite of anti-arrhythmic therapy, both administered class IB drugs may not be the best therapeutic approach.