We present the case of a 64 year old man, previously of good health, who presented in November 1995 with a short history of presyncope and one witnessed episode of syncope. On admission he was clinically in complete heart block with a ventricular rate of 40 beats/min but had a well maintained blood pressure at 150/80 mm Hg. Auscultation revealed a soft systolic murmur in the aortic area. The remainder of the examination was unremarkable. Resting ECG confirmed complete AV block with a slow regular broad complex ventricular escape rhythm. A Paragon III (Pacesetter, Coventry, UK) dual chamber pacemaker was subsequently implanted with complete resolution of cardiac symptoms.

He remained well for three months when he presented with sudden onset dyspnoea in January 1996. Further examination at this time …