Nadolol + diltiazem + nifedipine Cardiac conduction disturbances and hypotension in a patient during anae.thetic induction

A 58-year-old man with a history of hypertension and angina pectoris, treated with nadolol SOmg daily, diltiazem 90mg qid, nifedipine 10mg qid, isosorbide 20mg qid, furosemide [frusemide]4Omg daily, potassium supplement and cimetidine 400mg daily, was scheduled for 3 vessel coronary artery vein graft surgery. His ECG showed sinus bradycardia (40 beats/min) and first degree atrioventricular (AV) block. His BP was 124j70mm Hg and heart rate 44 beats/min.

Before surgery, the patient was given his usual morning doses of nadolol SOmg, diltiazem 9Omg, nifedipine 10mg and isosorbide 20mg plus 1M cimetidine 3OOmg, 1M morphine 10mg and 1M scopolamine [hyoscine] 0.43mg. On arrival in theatre he had BP 90/ 150mm Hg and heart rate 38 beats/min sinus rhythm. IV fentanyl 25 mg/kg and IV pancuronium 10mg were given in small divided doses over 10 min to induce anaesthesia. During this procedure, the patient developed an intermittent junctional rhythm with a rate of 35-40 beats/min and a systolic BP of 60mm Hg. IV atropine 2mg and IV ephedrine 22.5mg were unable to restore sinus rhythm and after tracheal intubation isoprenaline [isoproterenol] was infused at 4-16 ltg/min which resulted in a return to sinus rhythm at 45-55 beats/min and a BP of 100/ 40mm Hg. There was no indication of ischaemic ST changes during the prebypass period. Complications during bypass weaning included a junctional rhythm at 60 beats/min. Atrial pacing was instituted at SO beats/min and systolic BP was stable at 9O-100mm Hg. When the pacemaker was transiently turned off the patient was noted to be asystolic. The patient required continued atrial pacing. Perioperative infarction was not evident in the ECG although it did show advanced first degree AV block (PR interval of 0.36 sec). 22 hours after surgery the atrial pacemaker suddenly failed to capture, ventricular pacing was instituted but this did not prevent hypotension, supraventricular tachycardia and subsequent ventricular fibrillation from occurring. The patient died despite aggreSSive treatment.

The authors concluded that

'preoperative heart rate and conduction disturbances must be diligently assessed, and the possibility of temporary modifications of preoperative medical therapy considered' . Hartwell BL. Mark JB. AnestheSia and AnalgeSia 65. 905-907. Aug 1986

8 Reactions'" 18 OCt 1986 0157-7271 /86/10 18-{)()()8/0$0 1. 00/0 e> ADIS Press