OCUS ISSUE: CARDIAC RESYNCHRONIZATION THERAPY Normal QRS Duration and Resynchronization
نویسنده
چکیده
Cardiac resynchronization therapy has been shown to be an effective treatment for patients with systolic ventricular dysfunction, prolonged ( 120 ms) QRS duration, and New York Heart Association (NYHA) functional class III or IV symptoms despite optimal medical therapy. However, studies show that a majority of heart failure patients have QRS duration 120 ms. We have been investigating the potential utility of cardiac contractility modulating (CCM) signals as a treatment option for such patients. Cardiac contractility modulating signals are non-excitatory signals applied during the absolute refractory period using a pacemaker-like device that connects to the heart with pacemaker leads. Acute studies carried out in animals and humans with heart failure suggest that CCM signals can enhance the strength of left ventricular contraction. Results of initial long-term studies designed mainly to demonstrate feasibility and provide preliminary indication of safety in patients with medically refractory NYHA functional class III heart failure are summarized. The results of these preclinical and clinical studies formed the basis for proceeding with two prospective, randomized clinical studies currently underway to definitively test the safety and efficacy of this treatment. (J Am Coll Cardiol 2005;46:2229–36) © 2005 by the American College of ublished by Elsevier Inc. doi:10.1016/j.jacc.2005.05.093
منابع مشابه
Cardiac resynchronization therapy in patients with heart failure and a QRS complex <120 milliseconds: the Evaluation of Resynchronization Therapy for Heart Failure (LESSER-EARTH) trial.
BACKGROUND Although the benefits of cardiac resynchronization therapy are well established in selected patients with heart failure and a prolonged QRS duration, salutary effects in patients with narrow QRS complexes remain to be demonstrated. METHODS AND RESULTS The Evaluation of Resynchronization Therapy for Heart Failure (LESSER-EARTH) trial is a randomized, double-blind, 12-center study th...
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