Complex adult congenital heart disease is associated with impaired skeletal muscle function

Purpose: Complex congenital heart disease is often associatedwith impaired physical functioning, usually measured as peak oxygen uptake in an exercise test. Skeletal muscle function is, however, less studied in these patients. Methods: Unilateral isotonic shoulder flexion was tested in 79 adultpatients (mean age 36.6±14.8 years, 31 females) with congenital heartdisease, classed as either "complex" (n=41, 51.9%) or "simple" (n=38, 48.1%). The patients were sitting comfortably in a chair with their back touching the wall and holding a weight (2 kg for women and 3 kg for men) in the hand of the tested side. The patients were asked to elevate the arm, from 0 to 90 degrees flexion, as many times as possible. The pace of 20 contractions per minute was held using a metronome. Results: Patients with complex lesions performed less shoulder flexions compared with patients with simple lesions (29.2±10.0 vs. 54.6±25.8, p<0.001). In univariate analysis including a number of demographic and clinical variables, only complexity of cardiac lesion (p<0.001) and on-going cardiac medications (p=0.012) were associated with shouldermuscle function, of which complexity (p<0.001) remained significant in multivariate analysis. Conclusion: There is a marked difference in shoulder muscle functionbetween patients with complex and simple congenital heart disease. Such differences might affect ability to perform daily activities and contribute to impaired overall physical functioning. Rehabilitation targeting muscle function may be indicated in patients with complexcongenital heart disease.