This landmark trial indicates that many patients will not benefit substantially from dual chamber pacing. The results of this Canadian study should result in a more balanced view of single chamber pacing, which many specialists have, until now, viewed as being markedly inferior to dual chamber pacing. So called 'symptomatic bradycardia' is routinely treated by means of a permanent implanted cardiac pacemaker. These miniaturized, battery-driven, computerized devices are implanted surgically with a minor procedure. The pacemaker continuously monitors the patient's heart and stimulates the heart to beat if the heart fails to beat spontaneously.
Pacemakers are one of the first and most successful 'high tech' implanted medical devices.
There is no doubt they have improved quality of life and survival for millions of patients. Complications, such as movement of the pacemaker wire within the heart, infection around the pacemaker and component failure are uncommon but do occur in about 5 per cent of patients. It was widely believed that because of this abnormal sequence, single chamber pacing was the cause of a variety of symptoms such as palpitations, fatigue, shortness of breath and lightheadedness, sometimes known as the pacemaker syndrome. The development of a pacemaker that could pace both upper and lower chambers and maintain a more normal sequence of heart beating occurred about 15 years ago. Dual chamber pacing became increasingly popular when uncontrolled studies were reported which indicated that the dual chamber pacemaker patients seemed to be living longer and to be having a lower frequency of stroke, heart failure and abnormal heart rhythm known as atrial fibrillation.