title: Cardiac Resynchronization Therapy Leads to Improvements in Handgrip Strength.
abstract: BACKGROUND
  A reduction in skeletal muscle performance measured by handgrip strength is common in heart failure. No trial has investigated the role of cardiac resynchronization therapy, which leads to improvements in cardiac performance, on the function of skeletal muscle in patients with heart failure.
  
  
  METHODS
  Nineteen patients were recruited, 18 male, age 69 ± 8 years, New York Heart Association class II-IV, QRS duration 173 ± 21 ms and left ventricular ejection fraction 26±8%. Handgrip strength was measured at baseline before, and 6 and 12 months, following cardiac resynchronization therapy. Response was assessed using quality of life questionnaire, 6-minute walk distance, left ventricular end-diastolic volume, and cardiopulmonary exercise testing at the same time points.
  
  
  RESULTS
  Fourteen patients were identified as responders, demonstrating significant improvements in all four markers of response. There was no significant difference at baseline in left or right handgrip strength between responders and non-responders. Compared to baseline, handgrip strength significantly increased in responders during follow-up, left (34.4 ± 11.4 to 40.3 ± 11.3 kgf, P < 0.001) and right (35.7 ± 12.5 to 42.2 ± 11.5 kgf, P < 0.001) at 12 months. No such improvement was seen in non-responders.
  
  
  CONCLUSIONS
  This study demonstrates that positive response to cardiac resynchronization therapy is associated with significant gains in handgrip strength, suggesting that cardiac resynchronization therapy may indirectly lead to secondary gains in skeletal muscle function.
authors.affiliation: Medical Physics Group, Department of Cardiovascular Science, The Medical School, University of Sheffield, Sheffield, S10 2TN, UK; Department of Cardiology, Northern General Hospital, Sheffield Teaching Hospitals, Sheffield, S5 7AU, UK.
authors.forename: David R
authors.initials: DR
authors.lastname: Warriner
authors.affiliation: Medical Physics Group, Department of Cardiovascular Science, The Medical School, University of Sheffield, Sheffield, S10 2TN, UK.
authors.forename: Patricia
authors.initials: P
authors.lastname: Lawford
authors.affiliation: Department of Cardiology, Chesterfield Royal Hospital, Chesterfield, Derbyshire, S44 5BL, UK.
authors.forename: Paul J
authors.initials: PJ
authors.lastname: Sheridan
keywords: Cardiac resynchronization therapy; Handgrip strength; Heart failure