Granulomatosis with polyangiitis with cardiac and large vessel involvement: a case report with a constellation of rare complications.

Background: Granulomatosis with polyangiitis (GPA) is an autoimmune multisystem disorder characterized by small vessel vasculitis with granulomatous inflammation. In this report, we describe a unique case of GPA who presented with complete heart block (CHB) and developed complications due to intracranial large vessel involvement. Case summary: A 47-year-old gentleman presented with CHB with a background history of arthralgia and blood-tinged nasal discharge. Whole body positron emission tomography-computed tomography scan showed soft tissue thickening with increased fluorodeoxyglucose uptake in basal interventricular septum and mitral leaflet aorta from the root up to the renal arteries. The patient developed subarachnoid haemorrhage and stress-induced cardiomyopathy after pacemaker implantation. The patient responded dramatically to steroids and rituximab and the CHB resolved on follow-up. Discussion: Cardiac involvement in GPA is very rare as is the large vessel involvement. In this report, we describe the cardiac involvement of GPA in the form of basal interventricular septum and anterior mitral leaflet giving rise to CHB. The patient also had aortitis and vertebral artery aneurysm, which ruptured resulting in subarachnoid haemorrhage. The patient also developed stress-induced cardiomyopathy and monomorphic ventricular tachycardia. The patient improved with steroids and rituximab and is doing well on follow-up.