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CRT Upgrade Criteria — EECC MCQ

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ModerateCardiac DevicesCRT Upgrade CriteriaEECC

A 55-year-old man with non-ischaemic DCM (LVEF 20%) and narrow QRS (115 ms) has an ICD for primary prevention. He develops worsening HF symptoms and new AF. LVEF has dropped to 15%. His EP team discusses upgrading to a CRT-D. What QRS criterion must be met?

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Reveal the answer and explanation

Correct answer: D — CRT upgrade is only indicated if QRS has widened to ≥130 ms (ideally ≥150 ms with LBBB); CRT in narrow QRS (<130 ms) increases mortality based on the EchoCRT trial

The indication for CRT requires QRS ≥130 ms, with the strongest evidence for QRS ≥150 ms with LBBB morphology (Class I, LOE A). The EchoCRT trial definitively showed that CRT in narrow QRS (<130 ms) is harmful. Therefore, upgrading this patient's ICD to CRT-D requires documented QRS widening to ≥130 ms. If QRS remains narrow but he develops high RV pacing burden (>40%) from his ICD, then CRT upgrade may be considered to mitigate pacing-induced dyssynchrony. If QRS remains narrow and pacing burden is low, CRT is not indicated — focus should be on GDMT optimisation, AF management, and advanced HF therapies.

Reference: ESC (2021): Cardiac Pacing and CRT Guidelines; EchoCRT Trial