PHYSIOLOGICAL STIMULATION OF THE HEART – HISTORY AND THE PRESENT

Abstract

The possibility of electrical stimulation of the heart has fascinated researchers and doctors since the Age of Enlightenment until the 21st century. Cardiac pacing strategies have evolved from epicardial and myocardial to stimulation of the cardiac conduction system. Despite progress, many issues remain unresolved, including intraoperative determination of the optimal site for stimulation and pre- and postoperative assessment of left ventricular ejection fraction to select optimal patients and evaluate the treatment dynamics. Literature review was performed to evaluate the evolution of electrical myocardial stimulation, its modern methods, advantages and disadvantages. The evolution of electrical cardiac pacing has gone through stages from non-selective stimulation of the left and right ventricular myocardium to biventricular pacing and the latest milestone – the pacing of the conduction system – the bundle of His or its left bundle branches. Cardiac conduction system stimulation is today’s most physiological method of permanent cardiac pacing. However, it is not without some drawbacks, in particular, the need to perform the intraoperative evaluation of the effectiveness of myocardial resynchronization to have methods of objective assessment of left ventricular systolic function before and after resynchronization therapy in patients with significantly reduced ejection fraction. It is neccessary for the selection of optimal patients for biventricular pacing, or stimulation of the conduction system of the heart, and prediction of possible outcomes.