An ejection fraction (EF) of less than what percentage indicates severe heart failure and potential need for device therapy such as ICD or BiV pacing?

An ejection fraction (EF) of less than what percentage indicates severe heart failure and potential need for device therapy such as ICD or BiV pacing?

• A. <60%
• B. <20%
• C. <40%
• D. <50%

Answer: (C)

An ejection fraction shows how much blood the left ventricle pumps with each beat. Normal is about 55% to 70%. When EF falls below 40%, it signals substantial systolic dysfunction and a higher risk of symptomatic heart failure. At this level, clinicians start considering escalation to device therapies—an implantable cardioverter-defibrillator to reduce arrhythmic death and cardiac resynchronization therapy to improve ventricular coordination—after optimizing medical treatment. Thresholds below sixty, fifty, or twenty percent don’t align as clearly with severe dysfunction or the typical indication for these devices; the practical point at which device therapy becomes a consideration in this context is EF less than forty percent.

An ejection fraction shows how much blood the left ventricle pumps with each beat. Normal is about 55% to 70%. When EF falls below 40%, it signals substantial systolic dysfunction and a higher risk of symptomatic heart failure. At this level, clinicians start considering escalation to device therapies—an implantable cardioverter-defibrillator to reduce arrhythmic death and cardiac resynchronization therapy to improve ventricular coordination—after optimizing medical treatment. Thresholds below sixty, fifty, or twenty percent don’t align as clearly with severe dysfunction or the typical indication for these devices; the practical point at which device therapy becomes a consideration in this context is EF less than forty percent.