I work in a cardiology unit where the cardiologists are recommending a procedure called CRT to certain patients. Can you tell me something about it? - P.H., ARIZ.
Joan E. King, RN, C, ACNP, ANP, PhD, replies: Cardiac resynchronization therapy (CRT, also called biventricular pacing) is used for patients with heart failure who are symptomatic from systolic dysfunction despite optimal medical therapy. The device, a pacemaker with leads that pace both ventricles, is implanted in the upper chest.
About one-third of these patients have dyssynchronous ventricular contraction, also called cardiac dyssynchrony or ventricular dyssynchrony. This eventually leads to poor ventricular filling, reduced stroke volume and ejection fraction, and more severe mitral valve regurgitation, all of which contribute to worsening heart failure. Ventricular dyssynchrony has been associated with increased mortality in patients with heart failure.
The goal of CRT is to pace both ventricles in a synchronized fashion, enhancing ventricular contraction and reducing mitral regurgitation. Some devices also have defibrillation capability-an important advantage because these patients are at risk for sudden cardiac death. Studies have indicated that CRT reduces mortality and morbidity in patients with heart failure.
To be a candidate for a CRT device, a patient must have systolic dysfunction and heart failure resulting from ischemic or nonischemic cardiomyopathy, a New York Heart Association functional class of III or IV, a QRS complex duration of 120 milliseconds or more, and a left ventricular ejection fraction of 35% or less. In addition, he must be on maximal medical therapy and in sinus rhythm.
Caring for a patient with a CRT device is similar to caring for other patients with implanted cardiac devices. Obtain a 12-lead ECG to assess for proper CRT device function. Assess the patient for signs and symptoms of worsening heart failure, such as weight gain, pulmonary crackles, and peripheral edema. Monitor the chest implant site for active bleeding or hematoma, monitor the incision for signs of infection, perform incision care, and provide pain management.
Teach your patient about the signs and symptoms of worsening heart failure and when to call his health care provider. He should carry his device ID card at all times. Review the patient's medications with him and explain the importance of taking them as prescribed. Explain safety precautions; for example, he can't have magnetic resonance imaging.
By combining CRT with optimal medical management, patients can reduce heart failure signs and symptoms, improve functional capabilities, and reduce future hospitalizations.
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