Background The pectoral approach to implantation of cardioverter defibrillators (ICDs) has become a standard in defibrillator therapy because of reduced generator size, weight, and volume. But the size of these devices is still comparable to the size of the early conventional antibradycardia pacemakers that were associated with a number of significant pocket-and shoulder-related problems after implantation in the pectoral region. In a prospective, single-center study of 50 patients with subpectoral implantation of a fourth-generation ICD, the ipsilateral shoulder joint was evaluated regarding active shoulder motility, shoulder-related pain, shoulder function, shoulder elevation, insertion tendinitis, and morphologic alterations of the shoulder. Methods and Results The shoulder was evaluated before implantation and at 3, 6, and 12 months after implantation. Shoulder motility was documented by evaluating active abduction, forward flexion, and external rotation. Shoulder-related pain and function were documented by the "Basic Shoulder Evaluation Form," insertion tendinitis was diagnosed by standardized palpation and the impingment test, and morphologic alterations were documented by ultrasound and radiograph of the shoulder. Three months after implantation, 20 (40%) patients had a reduced active abduction, 30 (60%) patients had an impaired active forward flexion, and eight (16%) patients had a reduced external rotation. Thirty-one (62%) patients reported shoulder-related pain or impaired shoulder function according to the "Basic Shoulder Evaluation Form." Twenty-four (48%) patients showed a shoulder elevation and 21 (42%) patients demonstrated clinical signs of insertion tendinitis. After 12 months the number of patients with reduced active abduction, forward flexion, and external rotation dropped to four (8%). Shoulder-related pain and reduced function were documented in seven (13%) patients, four (8%) patients still had shoulder elevation, and five (10%) patients still had signs of insertion tendinitis. None of the postoperatively performed ultrasounds or radiographs showed any pathologic shoulder alterations. No predictors for the occurrence of shoulder-associated problems could be found. Conclusions (1) Decreased active shoulder motility, shoulder-related pain, reduced function, shoulder elevation, and insertion tendinitis of the ipsilateral shoulder joint are diagnosed in many patients 3 months after subpectoral ICD implantation. (2) After 12 months the number of patients with impaired shoulder motility, function, shoulder-related pain, shoulder elevation, and insertion tendinitis decreased significantly. (3) Ultrasound and radiographs of the ipsilateral shoulder showed no evidence of pathologic morphologic alterations after subpectoral ICD implantation. (4) No shoulder-associated problems required an operative revision of the subpectoral generator pocket.
