Changes in Myocardial Perfusion During Chronic Multi Site Biventricular Versus Right Ventricular Apex Pacing in Patients With Normal Left Ventricular Function Undergoing His Bundle Ablation for Drug-refractory Atrial Fibrillation
Changes in Myocardial Perfusion During Chronic Multi Site Biventricular Versus Right Ventricular Apex Pacing in Patients With Normal Left Ventricular Function Undergoing His Bundle Ablation for Drug-refractory Atrial Fibrillation
To determine whether Biventricular pacing in patients undergoing HIS bundle ablation for
 atrial fibrilation has beneficial effects on myocardial perfusion and left ventricularr
 ejection fraction.
Inclusion Criteria:

 -  Normal to nearly normal LVF (EF > 40%)

 -  Drug-refractory, persistent or permanent atrial fibrillation

 -  Referred for His ablation

 Exclusion Criteria:

 -  Unwilling or unable to sign the informed consent

 -  Life expectancy < 1year from non-cardiac causes

 -  Previous myocardial infarction

 -  Previous coronary bypass surgery

 -  Poor left ventricle function (EF< 40%) from any cause

 -  Symptomatic obstructive coronary artery disease

 -  Poor ultra sound imaging quality.