In recent years, the finding of long-term deleterious effects of right ventricular pacing (RVP) has led to an ongoing search for alternative pacing sites such as His bundle stimulation. The depolarization of the ventricles through the His-Purkinje cardiac conduction system seems to represent an ideal physiological approach to ventricular pacing, capable of engaging the normal conduction pathways and determining synchronous ventricular activation. However, there are still no clinical studies that have evaluated the electromechanical functions of the left ventricle with His bundle pacing (HBP) identified after electroanatomical reconstruction with 3D mapping system. Investigators aimed to compare the electromechanical effects on left ventricle of HBP, compared to RVP stimulation and to spontaneous rhythm of each patient.

Patients with indication for permanent pacemaker implantation were included in the study. The stimulation lead was positioned at the level of the His bundle after complete electroanatomical reconstruction of the atrium and right ventricle with 3D mapping system; a second backup lead was eventually placed in the right ventricle. Within 24 hours after implantation, each patient underwent 12-lead ECG and a complete echocardiographic examination in the different pacing modalities (HBP, RVP and patient's spontaneous rhythm) focused on the evaluation of biventricular systo-diastolic function, speckle-tracking and myocardial work of the left ventricle.

Inclusion Criteria:

• Patients with indication of class I or class IIa for permanent pacemaker implantation, in accordance with the guidelines of the European Society of Cardiology on cardiac pacing
• Age ≥ 18 years
• Written consent

Exclusion Criteria:

• Patients unable to express informed consent
• Pregnancy
• Severe mitro-aortic valve disease
• Left ventricular ejection fraction ≤ 35%

Patients over the age of 18 years with indication for permanent pacemaker implantation.