The present status of cardiac pacing.

At the time of its inception, pacemaker treatment only had the goal of reliably maintaining a regular ventricular rhythm. After solving technical problems of detection, function and introduction of AV-sequential pacing (1962), cardiac hemodynamics have become the central issue of interest. While, at low heart rates atrial contraction contributes meaningfully to cardiac output, it has been shown that for physiologic needs and high rates, rate-adaptive single-chamber stimulation is hemodynamically more favorable than non-rate adaptive AV-sequential pacing. A rate-adaptive stimulation, more suited to physiologic needs with incorporation of a combination of various control parameters will improve pacing technology in the future. Anti-tachycardia stimulation, now integrated into the function of the implantable cardioverter/defibrillator has substantially widened the scope of this aspect of pacing.