Left Ventricular Pacing Synchronization via Intrinsic Right Ventricular Depolarization
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Solution Overview
Problem
Patients with congestive heart failure and left bundle branch block often experience ventricular dysynchrony due to delayed activation of the left ventricle, leading to reduced cardiac output, which conventional cardiac resynchronization therapies fail to address effectively by pacing both ventricles simultaneously.
Innovation Solution
An implantable medical device measures the interval between atrial and intrinsic ventricular depolarizations to synchronize pacing pulses with the left ventricle, selecting optimal pacing intervals based on electrogram characteristics like QRS complex width and Q-T intervals to maintain ventricular synchrony, reducing power consumption by pacing the left ventricle independently.
Engineering Contradictions & Design Principles
Engineering Contradiction Analysis
1Reliability
If conventional biventricular pacing is used to treat ventricular dysynchrony, then cardiac resynchronization is achieved, but power consumption increases
Solution Approach 1:
The patent extracts the right ventricular pacing function from the conventional biventricular pacing system, leaving only left ventricular pacing. The device senses intrinsic right ventricular depolarizations and uses these as timing references to trigger left ventricular pacing, eliminating the need for active right ventricular pacing while maintaining cardiac resynchronization therapy benefits
Solution Approach 2:
The intrinsic right ventricular depolarization serves as the timing reference for left ventricular pacing, making the system self-regulating. The device uses the heart's own electrical activity to determine when to deliver left ventricular pacing pulses, eliminating the need for external programming and reducing power consumption compared to coordinated biventricular pacing
2Reliability
If left ventricular pacing is synchronized with intrinsic right ventricular depolarizations, then a more physiological interval between atrial and ventricularcontractions is achieved, but device complexity increases
Solution Approach 1:
The intrinsic right ventricular depolarization acts as an intermediary timing reference between atrial contraction and left ventricular pacing. The device detects the natural right ventricular electrical activity and uses it to trigger left ventricular pacing at the optimal moment, creating a physiological sequence without requiring complex coordination algorithms
Solution Approach 2:
The device continuously monitors intrinsic right ventricular depolarizations and adjusts left ventricular pacing timing based on these sensed events. This feedback mechanism ensures that pacing intervals adapt to the patient's natural cardiac rhythm variations, maintaining physiological timing while using simple sensing and timing circuitry
3Reliability
If pacing intervals are optimized based on electrogram characteristics, then ventricular synchrony is maintained, but measurement precision requirements increase
Solution Approach 1:
The device uses simple electrogram measurements from standard pacing leads to determine optimal pacing intervals. Rather than requiring complex imaging or advanced sensing technologies, the system uses readily available electrical signal measurements to guide pacing timing, maintaining ventricular synchrony with inexpensive measurement methods
Data Source
AI summary
The invention is directed to techniques for providing cardiac resynchronization therapy by synchronizing delivery of pacing pulses to the left ventricle with intrinsic right ventricular depolarizations. An implantable medical device measures an interval between an atrial depolarization and an intrinsic ventricular depolarization is measured. In various embodiments, the intrinsic ventricular depolarization may be an intrinsic right or left ventricular depolarization. The implantable medical device delivers pacing pulses to the left ventricle to test a plurality of pacing intervals. The pacing intervals tested may be within a range around the measured interval between the atrial depolarization and the intrinsic ventricular depolarization. One of the pacing intervals is selected based on a measured characteristic of an electrogram that indicates ventricular synchrony. For example, the pacing interval may be selected based on measured QRS complex widths and/or Q-T intervals. The implantable medical device paces the left ventricle based on the selected pacing interval.