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Pacing-induced Cardiomyopathy — EECC MCQ

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ModerateCardiac DevicesPacing-induced CardiomyopathyEECC

A 70-year-old man with a permanent pacemaker for complete heart block develops new HF symptoms. His echocardiogram shows LVEF has dropped from 55% to 38% over 3 years with RV pacing percentage of 98%. What has occurred?

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Correct answer: E — Pacing-induced cardiomyopathy — chronic RV apical pacing causes LBBB-like dyssynchrony, leading to LV dysfunction in 10-20% of patients with high RV pacing burden; upgrade to CRT (biventricular or conduction system pacing) should be considered

Pacing-induced cardiomyopathy (PICM) occurs in 10-20% of patients with chronic high-burden (>40%) RV pacing, particularly RV apical pacing. Mechanism: RV apical pacing produces an LBBB-like activation pattern → interventricular and intraventricular dyssynchrony → progressive LV remodelling and dysfunction (identical pathophysiology to native LBBB). Risk factors: higher RV pacing percentage (>40%), baseline LVEF <50%, wider paced QRS. The 2021 ESC Pacing/CRT Guidelines recommend: (1) minimise RV pacing when possible (algorithms: managed ventricular pacing, AV search hysteresis); (2) for patients requiring high-percentage ventricular pacing (complete heart block): consider CRT from the outset (Class IIa) or conduction system pacing (HBP/LBBAP); (3) upgrade to CRT if PICM develops (Class I if LVEF ≤35% with high RV pacing burden). PICM is often REVERSIBLE with upgrade to CRT — LVEF typically improves within 3-6 months.

Reference: ESC (2021): Pacing/CRT Guidelines