Apparatus and methods for automatic adjustment of av interval to ensure delivery of cardiac resynchronization therapy

摘要: The disclosure provides methods and apparatus of left ventricular pacing including automated adjustment a atrio-ventricular (AV) delay interval intrinsic AV nodal conduction testing. It includes—upon expiration or reset programmable Evaluation Interval (AVEI)—performing the following: temporarily increasing paced sensed testing for adequate measuring an (PR) right (RV) chamber. Thus, in event that test reveals physiologically acceptable PR then storing memory structure (e.g., median P-R from one more cardiac cycles). In block condition if unacceptably long intervals are revealed mode-switch to bi-ventricular (Bi-V) mode occurs magnitude AVEI is increased.