His Bundle Pacing, the First Experience Using a Conventional Pacemaker Leads

Background The classical pacing site at the right ventricular apex has been noticed to induce left ventricular function deterioration and heart failure over long pacing periods. Trials of right ventricular outflow tract pacing have been reported to reduce this problem in a few patients. Objectives His bundle pacing has been lately found to minimize pacing-induced cardiomyopathy significantly. Materials and Methods Patients included are those with high degree heart block, who needed conventional pacing and those with an indication for cardiac resynchronization therapy, where His bundle pacing was done as a substitute to a failed coronary sinus lead positioning for left ventricular epicardial pacing. His Bundle Pacing was done by blind His pacing site assessment through continuous ventricular pacing at the presumed His bundle site under fluoroscopy views. The leads used are conventional pacing leads. His bundle pacing was indicated by almost normal width paced QRS. Results His bundle pacing was successful in 30 patients from a total of 45 referred patients (67%). Fifteen patients with second or third-degree heart block who needed conventional pacing and 15 patients with an indication for cardiac resynchronization therapy, where His bundle pacing was done as a substitute to a failed coronary sinus lead positioning for left ventricular epicardial pacing. The 15 patients with high grades atrioventricular block did not show evidence of heart failure and dilated cardiomyopathy. The 15 patients with cardiac resynchronization therapy indication showed marked narrowing of the paced QRS, improvement in NYHA functional class, significant improvement of left ventricular ejection fraction, and reduction of cardiac size. Conclusion His bundle pacing is more physiological than right ventricular apical pacing and right ventricular outflow pacing as far as narrowing of the paced QRS, left ventricular function stability, and reduced incidence of pacing-induced cardiomyopathy. It is recommended in all conventional pacing indication. Whether patients with atrioventricular block or in cardiac resynchronization therapy indication when coronary sinus/left ventricular lead failed. Future availability of special leads and delivery system, improvement in leads, the design and positioning techniques at the His site may well improve the success rate of His bundle pacing and may replace left ventricular epicardial pacing in cardiac re synchronization therapy.