Augmentation of Cardiac Output by External Cardiac Pacing: Pacemaker-Induced CPR

Transthoracic cardiac pacing is frequently associated with simultaneous stimulation of skeletal muscle and nerves. We describe a patient in cardiogenic shock and complete heart block in whom the associated vigorous abdominal and chest muscle contractions caused by transthoracic cardiac pacing resulted in a marked augmentation of cardiac output and systemic blood pressure via a "CPR" effect     

Localised Nodular Myositis: a Clinical and Pathological Variant of Polymyositis

Three cases of a painful, inflammatory, nodular myopathy inyoung and middle-aged adult males are described. In two of thecases the nodular process gradually evolved into a diffuse proximalmyopathy accompanied by dysphagia, and manifesting the so-called‘facioscapulohumeral syndrome’. The electromyogram(EMG) in all three cases was ‘myopathic’ in typeand in two cases abnormalities consistent with an inflammatorymuscle disorder were seen. Muscle biopsy revealed a consistentpattern of intense, predominantly interstitial, pleomorphicinfiltration of muscle with scattered foci of muscle fibre destructionand regeneration, which resembled muscle infarcts. It is suggestedthat this syndrome, whilst readily recognizable from both theclinical and pathological standpoints, is not a nosologicalentity in its own right but rather an unusual presentation ofpolymyositis.     

Clinical Experience with New Leads

Recent developments in cardiac pacemaker electrodes have resulted in significant benefits to the group of pacemaker patients as a whole. The results of analysis of 2,818 chronic pacemaker electrodes are presented. These electrodes are divided into major categories according to their particularities: platinum iridium, elgiloy, carbon-tip, anodized platinum and granulated iridium-platinum. All leads were in the ventricular position. The results of acute and chronic threshold measurements reveal that carbon-tipped electrodes appear to have the most favorable overall characteristics. This will have a major influence on long-term pacing practices.