Question: what does it mean if your heart is only working at 35 percent?
Answer: If you have an EF of less than 35%, you have a greater risk of life-threatening irregular heartbeats that can cause sudden cardiac arrest/death. If your EF is below 35%, your doctor may talk to you about treatment with an implantable cardioverter defibrillator (ICD) or cardiac resynchronization therapy (CRT).