Investigation of Failure of Artificial Pacing

Abstract

a completely successful mitral valvotomy, or repair of an atrial septal defect, it is probably no longer needed. The effectiveness of quinidine, after conversion with direct-current shock, to lessen the relapse rate is being further studied.No complication in the present series has been serious. Extreme care is required and proper insulation of the apparatus is essential, especially when used at the time of thoracotomy. Ventricular tachycardia and fibrillation after direct-current shock in dogs appear to be related to the height of the voltage and the amount of energy used (Peleska, 1963). Our present plan for version is to use no more than four shocks, with energy increasing from 150 to 250, 350, and 400 watt sec.Relapse after successful direct-current shock seems most frequent if the left atrial pressure and volume remain above normal once sinus rhythm has been restored. This may occur in mitral-valve disease and in some of the cardiomyopathies. In the patients with " lone " atrial fibrillation there has been an as yet unexplained high relapse rate. Many of the patients with cardiomyopathy have been alcoholic, and failure to remove the provocative agent may contribute to their relapse. The need to repeat the procedure frequently should not arise; if the rhythm is constantly unstable, well-controlled atrial fibrillation is preferable to repeated changes of rhythm.In conclusion, a new method of treating arrhythmias has proved better than old methods for many patients, and it should have an established place for future practice. SummaryFifty patients who had atrial fibrillation, atrial flutter, or atrial tachycardia, resistant to treatment with drugs, were treated with direct-current shock. In 43 of these sinus rhythm was successfully achieved. The method is described and indications and contraindications for this form of treatment are given.Complications, which were few, are described. The results of a follow-up extending to nine months after successful treatment are given.We wish to thank the physicians and surgeons of the National Heart Hospital, and Drs. William Barratt, Richard Bomford, and Walter Somerville, who referred patients; Drs. John Beard and Alan Gilston, who gave the anaesthetics; Sister Curry, theatre superintendent of the National Heart Hospital, and her staff for willing assistance ; and Mr. John Norman, chief technician, the Institute of Cardiology, and his staff for technical help.ADDENDUM.-Since this paper was written a further 59 patients with arrhythmias have been treated with direct-current shock. The results in them have been similar and our conclusions the same. , 1964, 1, 1470-1474 The use of artificial pacemakers in the treatment of StokesAdams disease has increased rapidly over the past few years, and many patients who were previously bedridden or suffered from recurrent syncopal attacks have been enabled to live relatively normal lives. The combination of electronic and clinical attention required by patients with artificial pacemakers can best be provided by the specialized c...

Experience with Implanted Pacemakers: Technical Considerations

“…In treating 19 of our early patients a number of prototype units were tried, some from outside with only a receiver unit implanted, and others containing their own battery for power; some could be turned on and off, speeded up, and slowed down from outside. However, as a result of experimental work done in this hospital (Sowton, 1963), an early decision was taken to concentrate on the development of a fixed-rate pacemaker powered by miniature mercury cells within the implanted unit. There was no time for prolonged laboratory or animal trials since patients with complete heart block in whom Stokes-Adams attacks threatened life required pacing without delay.…”