This Article Full Text Full Text (PDF) All Versions of this Article: chest.07-2832v1 134/1/87    most recent Submit a response Alert me when this article is cited Alert me when eLetters are posted Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in ISI Web of Science Similar articles in PubMed Alert me to new issues of the journal Add to My Personal Article Archive Download to citation manager Google Scholar Articles by Kara, T. Articles by Somers, V. K. PubMed PubMed Citation Articles by Kara, T. Articles by Somers, V. K.

Short-term Effects of Cardiac Resynchronization Therapy on Sleep-Disordered Breathing in Patients With Systolic Heart Failure^*

^* From the International Clinical Research Center Brno (Drs. Kara, Novak, Nykodym, Meluzin, Orban, Lipoldova, Soucek, and Vitovec), St. Anne’s University Hospital Brno, Brno, Czech Republic; the Division of Cardiovascular Disease (Drs. Bybee, Hayes, and Somers), Mayo Clinic and Mayo Foundation, Rochester, MN; and the Department of Physiology (Dr. Novakova), Faculty of Medicine, Masaryk University, Brno, Czech Republic.

Correspondence to: Tomas Kara, MD, PhD, International Clinical Research Center Brno, St. Anne’s University Hospital Brno, Pekarska 53, 65691 Brno, Czech Republic; e-mail: kara.tomas{at}mayo.edu

Abstract

Objectives: We evaluated the short-term effect of cardiac resynchronization therapy (CRT) on sleep apnea in patients with systolic heart failure.

Background: Sleep-disordered breathing is common in patients with left ventricular systolic dysfunction.

Methods: Twelve patients (mean [± SE] age, 59.6 ± 7.8 years; mean left ventricular ejection fraction, 28.0 ± 2.8%) with an implanted atrial-synchronized biventricular pacemaker for the treatment of left ventricular systolic dysfunction were selected and studied. Each subject underwent polysomnography on 3 consecutive nights with CRT on the first night, CRT off the second night, and CRT on the third night. Echocardiography was performed prior to each polysomnogram.

Results: The central sleep event index (ie, the number of central sleep apneas [CSAs] and hypopneas per hour of sleep) score was lower with CRT compared to that without CRT (mean central sleep event index score with CRT on, 6.9 ± 1.7 events per hour of sleep; mean central sleep event index score with CRT off, 14.3 ± 2.9 events per hour of sleep; mean central sleep event index score with CRT on, 8.1 ± 1.5 events per hour of sleep; p < 0.001). Similarly, the cumulative duration of central sleep events (the number of minutes per hour of sleep during CRT) was one half that observed without CRT (CRT on, 2.8 ± 0.7 min per hour of sleep; CRT OFF 6.2 ± 1.2 min per hour of sleep; CRT ON 3.1 ± 0.7 min per hour of sleep; p < 0.001). There was a significant correlation between mitral regurgitant volume and central sleep event index on all three nights (r 0.77; p < 0.01).

Conclusions: CRT reduces CSA severity in the short term. This reduction correlated significantly with the CRT-mediated reduction of mitral regurgitation.

Key Words: cardiac resynchronization • mitral regurgitation • sleep apnea