title: Automatic Mode Switch (AMS) Causes Less Synchronization.
abstract: BACKGROUND
  Cardiac resynchronization devices are part of modern heart failure management. After implantation, we analyze and program devices in an attempt to ensure their success. Biventricular pacing should be 98% or more for the lowest mortality and best symptom improvement.
  
  
  METHODS
  In this case series, we present a combination of far field sensing and automatic mode switching (AMS) in six patients. It is found that this combination causes ventricular sensing (VS) episodes with wide QRS and no synchronization. We turn off the AMS and alleviate the problem.
  
  
  CONCLUSIONS
  Switching AMS off may increase biventricular pacing in some patients.
authors.affiliation: Cardiology Department, Shiraz University of Medical Science, Shiraz, IR Iran.
authors.forename: Mohammadvahid
authors.initials: M
authors.lastname: Jorat
authors.affiliation: Cardiovascular Research Center, Cardiology Department, Shiraz University of Medical Science, Shiraz, IR Iran.
authors.forename: Mohammadhossein
authors.initials: M
authors.lastname: Nikoo
keywords: Automatic Mode Switch; Biventricular Pacing; Cardiac Resynchoronization Therapy