Case Study: An Unusual Cause of Collapse

Dr Ben Wiles (Cardiology ST5) & Dr Richard Bala (Consultant Electrophysiologist)
Dorset Heart Centre, Royal Bournemouth Hospital, Castle Lane East, Bournemouth, BH7 7DW

A 51 year old gentleman presented to the Emergency Department of our district general hospital whilst on holiday in the local area. He gave a short history of recurrent syncope, with three episodes of transient loss of consciousness occurring that day. He also complained of intermittent symptoms of dizziness and light headedness over the same period. He denied angina or breathlessness. On arrival to the emergency department he complained of on-going light headedness and marked fatigue.

On physical examination he had a regular heart rate of 105 beats per minute and a blood pressure of 97/55. His jugular venous pressure was not raised. He had normal first and second heart sounds with no added sounds. His chest was clear and he had bilateral pitting oedema of the lower limbs. His saturations were 96% on room air and his respiratory rate was 16 breaths per minute.  His Glasgow Coma Scale score was 15/15. Examination of the precordium revealed a median sternotomy scar consistent with previous cardiac surgery.  An ECG was performed (Figure 1).

Figure 1

The ECG was noted to be abnormal, although the diagnosis was not immediately apparent. There was no clear p wave pattern and the baseline of the ECG appeared to show coarse irregular fibrillation waves. However there was an identifiable regular pattern of narrow QRS complexes suggesting an underlying regular ventricular rhythm. The attending physician felt that this ECG represented coarse atrial fibrillation. A cardiology opinion was sought and a differential diagnosis of sinus rhythm with baseline artefact was proposed. However neither diagnosis could explain the patient’s symptoms or his recurrent episodes of syncope. 

A transthoracic echocardiogram was performed by the on call cardiology registrar. Parasternal long axis and apical views of the heart were obtained. These showed that the left ventricle was in fact not contracting. Fibrillation of the ventricle was evident with no valvular excursion.  The patient’s GCS however remained 15/15 and his systolic blood pressure remained greater than 90 mmHg on non-invasive monitoring.

A right sided parasternal view was then obtained. This revealed that the patient did in fact have two hearts; a native heart in ventricular fibrillation and a donor heart with normal left ventricular systolic function. A diagnosis of heterotrophic cardiac transplantation with native heart ventricular fibrillation was therefore reached.

The patient was discussed with his transplant centre. He had suffered from a dilated cardiomyopathy in adolescence and received a heterotrophic cardiac transplantation 30 years prior to his presentation to our hospital.

He was transferred to our Coronary Care Unit where he underwent an emergency DC cardioversion under general anaesthetic. Sinus rhythm was restored in the native heart after a 200J synchronised DC shock.  A further ECG was undertaken (Figure 2).

Figure 2

This revealed two competing QRS patterns; the native heart in atrial fibrillation and the donor heart in sinus rhythm.  There was an immediate symptomatic improvement in the patient post cardioversion, with resolution of his dizziness and fatigue. Transthoracic echocardiography was repeated. Normal left ventricular systolic function was observed in the donor heart, whilst the native heart showed severe left ventricular systolic dysfunction as documented at his most recent follow up at the transplant centre. The patient was subsequently repatriated back to the transplant centre for further management.

We have presented an unusual case of collapse in a cardiac transplant recipient. We hope it will be of interest to all who have an interest in cardiac rhythm management. The diagnosis of native heart ventricular dysrhythmia should always be considered in heterotrophic transplant recipients who present with syncope or haemodynamic compromise. This diagnosis should also be considered in patients with evidence of previous cardiac transplant or surgery, where surgical or transplant details are unknown.

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