RESUMEN
INTRODUCTION: Despite optimal drug treatment, many patients with congestive heart failure (CHF) or COPD still experience disabling dyspnea, fatigue, and exercise intolerance. They also exhibit significant changes in body composition. Attempts to rehabilitate these patients are often futile because conventional exercise-training modalities are limited by the severity of exertional dyspnea. Therefore, there is substantial interest in new training modalities that do not evoke dyspnea, such as transcutaneous neuromuscular electrical stimulation (NMES). MATERIALS AND METHODS: In this article, we systematically review the literature that addresses the effects of NMES applied to the muscles of ambulation. We focused on the effects of NMES on strength, exercise capacity, and disease-specific health status in patients with CHF or COPD. We also address the methodological quality of the reported studies as well as the safety of NMES. Manuscripts published prior to December 2007 were identified by searching the Medline/PubMed, Embase, Cochrane Controlled Trials Register, CINAHL, and Physiotherapy Evidence Database (PEDro) databases. RESULTS: Fourteen trials were identified (nine trials that examined NMES in CHF patients, and five in COPD patients). PEDro scores for methodological quality of the trials were generally moderate to good. Many of the studies reported significant improvements in muscle strength, exercise capacity, and/or health status. DISCUSSION: Nonetheless, the limited number of studies, the disparity in patient populations, and the variability in NMES methodology prohibit the use of metaanalysis. Yet, from the viewpoint of a systematic review, NMES looks promising as a means of rehabilitating patients with CHF and COPD. There is at least sufficient evidence to warrant more large prospective, randomized, controlled trials.