Management of Complex Ventricular Arrhythmias in Heterotopic Heart Transplant Patients

Abstract

A 55-year-old woman was admitted with palpitations on a background of heterotopic heart transplantation 13 years earlier. Prior to transplant, a dual-chamber permanent pacemaker was implanted in her native heart for a severe ischaemic cardiomyopathy with a left ventricular ejection fraction of 5%. Post-transplant, our patient's donor heart had been affected by both allograft vasculopathy requiring percutaneous coronary intervention and one episode of cellular rejection. Her current donor left ventricular ejection fraction was 40%. Our patient's palpitations were identified as recurrent episodes of native heart ventricular tachycardia lasting up to 21 hours at rates of 180 beats per minute. Direct cardioversion to the native heart was performed twice, unsuccessfully. Amiodarone infusion also failed to control the burden of ventricular tachycardia. Lignocaine was then added, but at this point the patient developed bradycardia in the donor heart. In the setting of competing native tachycardia and donor bradycardia, our patient developed cardiogenic shock due to her doubly low-output state. Further cardioversion to the native heart was considered too high risk given the new donor bradycardia. A dual-chamber permanent pacemaker was implanted into the donor heart. Anti-tachycardic therapy was optimised to bisoprolol, oral amiodarone, and mexiletine. With aggressive anti–arrhythmic therapy, ventricular arrhythmias in the native heart ceased while the donor heart was supported with pacing. This is the first report of double dual-chamber pacemakers being implanted in a heterotopic heart transplant recipient to treat complex competing arrhythmias. This case emphasises the difficult balance of controlling two connected cardiomyopathic hearts developing conflicting arrhythmias.