How is cardiac resynchronization therapy different from cardiac resynchronization with defibrillation therapy?
CRT is used to treat heart failure. Some heart failure patients are also at high risk for sudden cardiac death. These patients may benefit from CRT with defibrillation therapy. A CRT device that also provides defibrillation therapy is called a cardiac resynchronization therapy defibrillator (CRT-D). Sudden cardiac death begins when the heart develops a dangerously fast rhythm called ventricular fibrillation. The heart’s contractions become so fast and chaotic that the heart cannot pump blood to the body. If not treated immediately, death occurs in a few minutes. In addition to treating heart failure, a CRT-D detects and treats those dangerously fast heart rhythms that can lead to sudden cardiac death. The device continuously monitors the heart’s rhythm. If a dangerous rhythm appears, the CRT-D delivers a shock to stop the fast rhythm and return the heart to a normal rhythm.
