Syncope after Heart Transplantation findings. Echocardiography showed markedly enlarged cardiac chambers with severely reduced left ventricular (LV) systolic function [ejection fraction (EF) = 8%] and well functioning prosthetic mitral valve. Despite optimal medical treatment, including diuretics, digoxin, angioten- sin converting enzyme inhibitors and inotropics, his symptoms were not relieved. He underwent heart transp- lantation with bicaval technique on 15th, July, 2007. The immunosuppressive regimen consisted of cyclosporine (target blood trough level: 250 - 350 ng/mL), mycopheno- late mofetil and prednisolone. The blood trough level of cyclosporin was 323 ng/mL. Follow-up echocardiography after heart transplantation showed normal LV systolic function (EF = 60%). He felt mild dizziness with sinus bradycardia (< 50 beats/min) during hospital stay. On day 22, he had an event of syncope in the early morning that was due to prolonged sinus arrest (10 seconds), which was Fig. 1. Sinus arrest was captured for 10 seconds on telemetry on day 22 after heart transplantation. Fig 2. Endomyocardial biopsy showed no evidence of rejection. Normal myocardium without lymphocytic infiltration or myocyte damage. confirmed on telemetry (Fig. 1). The endomyocardial biopsy specimen showed no rejection, according to International Society for Heart Transplantation Classification (Fig. 2). Follow-up echocardiography showed no significant interval changes. After temporary pacemaker insertion, he had still symptomatic bradycardia (< 50 beats/min) and sinus arrest (8 second). Finally, he underwent insertion of a permanent VVI pacemaker on day 32. He was discharged without symptoms and was followed at outpatient clinic. DISCUSSION The standard heart transplantation technique originally described by Lower and Shumway involves removal of both donor and recipient hearts at the midatrial level.3 This biatrial technique preserves the multiple pulmonary venous connections to the recipient’s left atrium. The great vessels are resected just above the semilunar valves. This techni- que has been associated with postoperative problems in some patients, including atrial dysrhythmias, atrial dysfunc- tion, thrombus formation, and tricuspid valve dysfunction. In the early 1990s, a variation of the standard procedure, called the bicaval technique was introduced.4,5 This proce- dure uses resection of the superior and inferior vena cavae, preserving the integrity of the right atrium. The theoretical advantages of this technique are the preservation of atrial contractility, sinus node dysfunction, and tricuspid valve competence. However, Meyer et al.6 reported disadvantages of bicaval technique such as prolonged cross-clamp and donor ischemic time. The donor was a 37-year-old male who was sentenced to brain death due to acute cerebral hemorrhage. He had a history of hypertension on anti-hypertensive medication. The ischemic time of donor’s heart was 180 minutes. Our patient successfully underwent heart transplantation by bicaval technique, and no evidence of rejection was then noted on endomyocardial biopsy and echocardiography. Perhaps, the most possible cause of sinus node dysfunction in this patient was surgical trauma at the time of transplan- tation. Although normalization of posttransplantation sinus node dysfunction and bradyarrhythmias occurs in up to 55 percent of patients during the first three postoperative months,7 patients with more severe symptomatic bradycar- dia that persists for more than two weeks or sinus arrest after transplantation usually require a permanent pace- maker.8 Rothman et al.9 noted sinus node dysfunction in 14 (42%) of 33 patients who underwent biatrial anastomosis and 2 (5%) of 37 patients who underwent bicaval anasto- mosis. Because sinus node dysfunction in the transplanted heart does not predict subsequent development of atrioven- Yonsei Med J http://www.eymj.org Volume 50 Number 4 August 2009 589