Two Years’ Clinical Experience with the Implantable Pacemaker for Complete Heart Block

1. A subcutaneously implanted electronic prosthesis was used in 42 patients for the correction of complete heart block. 2. A total mortality of eight cases has occurred, with four deaths within 20 days of operation. Of four late deaths, three were due to intrinsic myocardial disease and one presumably related to intermittent pacemaker function. 3. The 34 surviving patients are currently pacemade and rehabilitated with a follow-up varying from one to 25 months and a mean follow-up of 11.5 months. 4. The complications and difficulties seen in the early phase of this clinical experience were chiefly caused by the mechanical breakdown of the electrode then in use. The mechanical and electrical stability of the platinum-iridium coil electrode used in the last 26 patients has been satisfactory, without exception. 5. Recent improvements in the design of the implanted pacemaker have been described. These include a reduction in size, and addition of rate and amplitude controls which can be actuated by the physician by a simple percutaneous puncture.