A Case Report of Pacemaker-Induced Cardiomyopathy in a Patient With Post-atrioventricular Node Ablation for Atrial Fibrillation.

Pacemaker-induced cardiomyopathy (PICM) is a rare but well-recognised phenomenon in patients requiring right ventricular (RV) pacing. It can be caused by single-chamber or dual-chamber pacemakers. We present a case of a 64-year-old female patient presenting to the pacemaker clinic with worsening shortness of breath and legs swelling. She was found to have atrial fibrillation and underwent atrioventricular node ablation followed by a dual chamber permanent pacemaker (PPM) implantation as part of a 'pace and ablate' strategy to treat refractory symptomatic atrial tachycardia, and the patient was entirely dependent on RV pacing. In the immediate two months following PPM implantation, the patient was seen in the clinic and reported shortness of breath that was attributed to interstitial lung disease. However, a month later her symptoms worsened, stimulating a referral for echocardiography, which demonstrated a fall in her left ventricular ejection fraction (LVEF) from 60% to 30% in just four months after the device implantation. The patient was diagnosed with PICM. The patient's prognostic heart failure treatment was optimised and her device was upgraded to a cardiac resynchronisation (CRT) device with pacing functionality in an attempt to improve biventricular synchrony. The patient's symptoms have improved significantly since and a repeat echocardiogram 2 months later showed significant improvement in LVEF to 45-50%.