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Left ventricular approach for recording His bundle potential in man
Insights
This study demonstrates stable His bundle (HB) and left bundle branch (LB) potential recordings from the left ventricle. These left-sided recordings provide reliable electrophysiologic data comparable to right-sided measurements.
Area of Science:
- Electrophysiology
- Cardiology
- Medical Imaging
Background:
- Accurate electrophysiological mapping is crucial for diagnosing cardiac conduction abnormalities.
- Traditional His bundle electrograms (HBE) are typically recorded from the right ventricle.
- Left ventricular endocardial recordings offer an alternative approach for assessing cardiac conduction.
Purpose of the Study:
- To evaluate the feasibility and reliability of recording His bundle (HB) and left bundle branch (LB) electrical potentials from the left ventricular endocardial surface.
- To compare electrophysiological intervals measured from the left ventricle with those from the right ventricle.
- To identify specific clinical scenarios where left-sided electrophysiological studies are indicated.
Main Methods:
- Recording His bundle (HB) and left bundle branch (LB) potentials using a bipolar electrode catheter from the left ventricular endocardial surface in 28 patients.
- Measuring key electrophysiological intervals including P-A, A-H, H, H-V, LB, and LB-V.
- Validating left-sided recordings through simultaneous intracardiac electrograms from both left and right sides of the heart in 18 patients.
Main Results:
- Stable recordings of HB and LB potentials were achieved from the left ventricular endocardium.
- Average electrophysiological intervals (P-A, A-H, H, H-V, LB, LB-V) were determined in patients with normal A-V conduction.
- Left-sided and right-sided recordings showed statistically similar interval values, with a slightly longer H potential duration from the left heart (P=0.05).
- Simultaneous onset of H potentials and comparable LB-V and right bundle branch-ventricle (RB-V) conduction times were observed.
Conclusions:
- Left ventricular endocardial recordings provide a reliable method for obtaining His bundle (HB) and left bundle branch (LB) electrograms.
- Left-sided electrophysiological measurements are comparable to right-sided measurements, offering a valuable alternative.
- Left-sided studies are indicated when right-sided HB recording is not feasible, in cases of giant right atrium, or potentially during atrial fibrillation.
Abstract:
The electrical potentials of the His bundle (HB) were recorded from the left ventricular endocardial surface in 28 patients ranging from 16 to 63 years of age. In 14 of the patients the left bundle branch (LB) potentials were also obtained. Placement of a bipolar electrode catheter tip toward the interventricular septum, right at and also 1 to 2 cm below the aortic valve, resulted in stable recordings of both potentials in successive cardiac cycles even at performing atrial or HB pacing from the right heart. The following intervals were measured in milliseconds (msec): P-A, A-H, H, H-V, LB, and LB-V. The average values in 12 patients (average age 26 plus or minus 7 years and average heart rate 90 plus or minus 16 beats per minute) with normal A-V conduction were as follows: P-A 28 plus or minus 7, A-H 76 plus or minus 16, H 19 plus or minus 3 and H-V 45 plus or minus 6 msec. The average values for LB and LB-V in 10 of these 12 patients were 15 plus or minus 3 and 25 plus or minus 3 msec respectively. Validation of the His bundle electrogram (HBE) from the left ventricular endocardial surface was based on simultaneous recordings of the intracardiac electrograms from both left and right sides of the heart in 18 patients. The individual average values for the intervals obtained from both sides of the heart in these patients were statistically not different, except that the H potential was slightly longer in duration fr m the left heart (P equals 0.05). Among these, 16 showed simultaneous onset of the H potentials, and the LB-V and RB-V conduction times from comparable points were almost the same. Indications for the left sided electro-physiologic studies include the following situations: (a) inability to record H from the right of the heart; (b) giant right atrium; and (c) possibly during atrial fibrillation.