Pulsatile abdominal mass is not always leaking aneurysm!

An 80-year-old male, who presented with a history of unprovoked collapse, was found to have a visible pulsation in the central upper abdomen, which disappeared on raising his arms above his shoulder ('head and shoulder' technique). There was no tenderness noted over the pulsation. He had a ventricular demand inhibited pacemaker inserted 3 weeks ago for a significant bradycardia with atrial fibrillation. His ECG showed heart rate of 32 bpm with underlying atrial fibrillation. No pacing spikes noted. His chest x-ray confirmed displacement of pacing lead into the right subclavian vein. It caused stimulation of phrenic nerve resulting in rhythmical diaphragmatic contraction. He later had his pacemaker re-inserted with no more collapses.