Antiarrhytmogenic Effect of Multisite Pacing

From observations of traditional or remote monitoring follow–up, only 2% of 35 patients with CRT–D had episodes of NSVT. In contrast, 25–35 % of patient with single–chamber and/or dual chamber ICDs had episodes of NSVT or ATP interventions or DC shoks for severe arrhythmias. From our follow–up observations on hundreds of patients, it has emerged that multisite pacing of CRT, with high percentages of stimulation (90 – 100 %), compared to single–chamber and dual–chamber devices, in addition to allowing a wide programming reserve in Cardiac Rhythm Management (CRM) and reverse remodeling of the left ventricle, exerts an antiarrhythmic effect on supraventricular and ventricular arrhythmias, with a lower burden of atrial fibrillation , resulting in fewer ATP and DC shock interventions by the devices on malignant arrhythmias. Biventricular pacing, especially with quadripolar leads (Figure 1), provides synchronous orthogonal recruitment of healthy and scarred miocardium; wich reduces the dispersion of refractory periods of pathological substrates, characterized by area of fibrosis, in severe heart desease. The lower heterogenicity of substrates, ultimately generates fewer reentry circuits, reset by multisite pacing, making this type of stimulation safe and effective (Figure 2) in the electromechanical control of heart.