LAUSR

Nowadays, most cardiologists are familiar with orthotopic heart transplantation (OHT) for end-stage heart failure. Nevertheless, in the pre anti-rejection-therapy era (early seventies of the previous century), surgeons rather connected the transplant organ to the native heart, a technique called heterotopic heart transplantation (HHT). By not explanting the native heart, a kind of parallel biventricular support system to the native circulation was designed, causing less harm upon (acute) graft-rejection, which was very common at that time. We present a 29-year-old man with a previous HHT at the age of four for idiopathic dilated cardiomyopathy. He presented with new onset of continuous palpitations. At first sight, the underlying rhythm on the ECG at presentation (Figure 1) seems confusing but when studied more in detail, two different QRS-morphologies and two different rhythms (one right bundle-branch block in sinus rhythm and one atypical bundle-branch block in atrial fibrillation (AFib)) can clearly be distinguished. Echocardiography confirmed the native heart to be in AFib (mitral valve inflow pattern), although both native and donor hearts showed sinus rhythm on previous traces (Figure 2). This ECG illustrates a tachyarrhythmia of the native heart, known to be an important disadvantage of HHT. HHT is, at present, a far less useful technique compared to orthotopic heart transplantation because of the improvements in immunosuppressive therapy, the development of efficient long-term mechanical circulatory support and HHT’s potential disadvantages such as increased rates of thromboembolic events and rhythm disorders [1]. Although HHT is still very rarely performed, it is still common in selected cases, such as patients with fixed pulmonary hypertension to avoid heart-lung transplant (the additional pump function of the donor right ventricle to the failing native right ventricle has shown to be beneficial in overcoming pre-existing (fixed) pulmonary hypertension) or in patients with major donor-recipient bodysize mismatch as was the case in our patient [1,2]. Therefore, comparable ECG-traces are nowadays rarely seen and unknown to most cardiologists.