All concepts, explanations, trials, and studies have been re-written in plain English and may contain errors. I am not a doctor ----------------------------------------------------------- Dual-Chamber Pacing Effective in Selected Patients With Hypertensive Hypertrophy August 30, 1999 - Patients with enlarged left ventricles caused by high blood pressure respond to dual-chamber pacing, say Johns Hopkins researchers in the August 24 issue of Circulation: Journal of the American Heart Association. Dr. David Kass and colleagues implanted dual-chamber pacemakers in 9 patients with hypertensive left ventricular hypertrophy complicated by above normal ejection fraction, distal cavity obliteration and severe shortness of breath on exertion. They set the pacemaker to shorten the atrial-ventricular delay. Patients were either paced or not, for 3 months. Then for the following 6 months, all patients had their pacemakers activated. After 3 months of active pacing, ability to exercise duration rose from an average of 324 seconds to 588 seconds. Maximum oxygen consumption increased from 14 to 17 mL/min per kilogram. Seven of the 9 patients had more than 30% improvement in exercise tolerance. Symptoms and ability to do daily activities improved with pacing, and this improvement lasted throughout the one year follow-up period. Dr. Kass and colleagues say that dual-chamber pacing "may provide an alternative" for patients with this condition in whom drug therapy has failed to help symptoms. In an editorial, Dr. Robert O'Rourke warns that "pacing should never be considered primary therapy in patients with cardiomyopathies." He also cautions that "hemodynamic improvements do not always translate into a survival benefit, and very careful patient selection is mandatory. The determination of an appropriate AV interval (usually short) is crucial to the success of dual-chamber pacing in the myopathic heart." Circulation 1999;100:786-788, 807-812 ========================================================== Pacing for Congestive Heart Failure Dr. Angelo Auricchio from Germany presented a study of pacing therapy for congestive heart failure. This study was based on the theory that CHF patients who ALSO have a prolonged QRS duration might benefit from pacing which could improve the contraction pattern of the ventricle. Patients got dual pacemaker implant to achieve both left and right ventricular pacing. This also required a thoracotomy for lead placement. A detailed study was performed to optimize the pacing. Then patients were randomized to have either biventricular or left ventricular pacing. They had pacing turned on and then had it turned off and turned back on again. Each pacing period was for 4 weeks. The primary outcomes were the oxygen uptake at peak exercise, the oxygen uptake at anaerobic threshold and the distance on the 6-minute walk test. The results were that all of these responded well to pacemaker therapy. It did not seem to matter whether the patient got left ventricular pacing or biventricular pacing but it was clear that these 2 pacing modes were better than right ventricular pacing alone. This study was small - 42 patients. The results are, however, encouraging. ======================================================= Guidant Announces European Market Release of CONTAK/EASYTRAK Product Family for CHF Treatment November 11, 1999 - Guidant Corporation has announced the European release of a family of products designed for CHF patients. This includes the CONTAK CD and CONTAK TR devices and the EASYTRAK lead system. "Our experience indicates that a CONTAK/EASYTRAK system can provide significant benefit in treatment of CHF patients," noted Jay Graf of Guidant. "Treatment of chronic heart failure is an enormous clinical need and a large part of healthcare budgets worldwide is spent on CHF. We have confidence that these device systems can help relieve symptoms." Guidant's CHF device systems include the CONTAK CD pulse generator, which provides biventricular stimulation, bradycardia pacing and tachyarrhythmia cardioversion/defibrillation; the CONTAK TR pulse generator, which provides biventricular stimulation and bradycardia pacing; and the EASYTRAK lead, a transvenous over-the-wire lead system developed for implantation in the coronary vein system to reach the left side of the heart. The EASYTRAK lead is designed to stimulate both of the lower chambers of the heart in a way that enhances the heart's pumping efficiency. Other systems provide pacing to stimulate only the right side of the heart and rely on the heart's normal conduction system to transfer that pulse to the heart's left side. The EASYTRAK lead system allows easy transvenous placement, using a system similar to that used in angioplasty. ====================================================== CTOPP - Pacemaker Therapy The CTOPP trial was done in 31 Canadian pacemaker centers. The theory was that dual chamber pacing would reduce the risk of heart-related death or stroke in patients needing a pacemaker. Patients had to be about to receive a first pacemaker and they could NOT have chronic a-fib. They got either a "physiologic" pacemaker - a dual chamber pacemaker or an atrial pacemaker - or they got a single-chamber ventricular pacemaker. It was really a comparison between dual chamber pacing and single chamber ventricular pacing. A total of 2,560 patients were enrolled. The average follow-up was 3 years. The results showed no significant reduction in heart-related death or stroke with physiologic pacing. Currently there is no evidence that physiologic pacing prolongs life more than single chamber ventricular pacing. There IS evidence that it prevents atrial fibrillation but the effect is modest. There will be other trials addressing the same issue: the MOST trial from the USA and the British PACE trial. ======================================================== The PATH-CHF (Pacing Therapies for Congestive Heart Failure) group announced an early end to their trial testing the benefit of pacemakers for patients with moderate to severe congestive heart failure. PATH-CHF is the first study of patients with CHF, greatly reduced exercise capacity, severely impaired quality of life and high hospitalization rates that has shown large improvements in those areas after pacemaker implant. The pacemaker provides coordinated beating of the heart's chambers. Pacemaker software was developed specifically for this trial by the manufacturer, who sponsored the trial. There was immediate improvement of symptoms, especially in longer exercise time - by more than 20% of the pre-pacemaker time. Of the 42 patients implanted with a pacemaker, only one patient died from progressive heart failure over an average follow-up of 12 months. The main researcher for the trial is Dr. Angelo Auricchio from the University Hospital Magdeburg in Germany, who enrolled the first patient into the study in August of 1995. Six other European University hospitals were in the study. According to Dr. Auricchio, almost all patients in the study achieved impressive improvement of well-being and exercise capacity. Several were scheduled for heart transplant due to severe symptoms but after implant, they were removed from the transplant list due to improved condition. Despite improvements in drug treatment, heart failure is one of the leading causes of hospitalization and death in Europe and the USA. The costs involved in treating CHF in the USA are equal to the cost of treating cancer and heart attack *combined*. The final results of the PATH-CHF study have been submitted for publication and will be presented at the annual meeting of the North American Society for Pacing and Electrophysiology (NASPE) in Toronto, May 12 - 15, 1999. Title: Multisite Pacing: A New Hope for Patients with Congestive Heart Failure Dr. Auricchio can be contacted at: Dr. Angelo Auricchio Department of Cardiology Leipzigerstr 44 University Hospital Magdeburg, Germany FAX: + 49 391 67 15 211