In October 2015 I was implanted with a pace maker which used a His Bundle (HB) lead.Every thing it seems now is thought of or written about as a journey so I tell my journey.
Since I developed a high grade second degree heart bock that was precipitated by exercise and a left bundle branch block (LBBB) also,I was a candidate for a pacemaker (PM) and cardiac resynchronization therapy (CRT) which at the time was synonymous with bi-ventricular pacing (BI-V) .
BiV has been accomplished by atrial pacing,right ventricular pacing and left ventricular pacing which was done by inserting a pacing lead into a vein of the epicardial surface of the left ventricule (LV) .which was accessed by placing a catheter into the coronary sinus in the right atrium and threading it into a LV epicardial vein.
My EP cardiologist had a different approach. He implanted a lead in the right atrium and placed the ventricular lead near the bundle of His in the interventricular septumThe third lead was placed in a vein on the surface on the left ventricle.This bi-V approach is done in cases of heart failure (HF) in which there is significant desynchrony of the left ventricle (LV) which reduces cardiac output and leading to significant deleterious cardiac remodeling.
The LV lead was to be a back up lead and in the first five years was not needed as during implantation the Right ventricular catheter recorded a His Bundle signal which captured the Purkinje System and provided a narrow QRS complex replacing the LBBB. The HB pacing was considered to be "non-select" HB pacing as both the His Bundle and a portion of myocardium was stimulated giving an EKG with a delta wave resembling the EKG of an anteroseptal preexcitation pattern.
Non select HBP is thought to be as effective as select HBP ( in which there is only capture of the His Bundle and the EKG has an isoelectric interval between the stimulus and ventricular capture signal) in terms of cardiac output.
HBP typically has requested a higher capture voltage than does right ventricular apical capture and has a greater incidence of need for lead replacement and may have a lower r wave. HBP has also required a longer implantation time and higher incidence of failure to capture rate. All of those issues have become much less of an issue as operator experience has increased and better catheters have become available with procedure times being shortened, capture threshold lower, and fewer cases of that require a lead replacement.
The post implantation period was not without drama. The first night the chest pain was severe and frightening and I felt lightheaded. I had been NPO from midnight of the day preceding the procedure day and although the procedure was scheduled for 7 am , because of an intervening emergency it was after one pm before I went into the cath lab by which time I was likely moderately volume depleted.
This lead to a situation in which I had chest pain and a low blood pressure.My wife also a physician were able to convince, badger and intimidate the rookie nurse to run in more fluid.The fluid and a shot of morphine relieved the pain and volume depletion correction alleviated the weakness.
3 days later I developed left sided pleuritic chest pain,a heart rate of 150 (shown to be atrial flutter on EKG) and an emergency Pulmonary CT angio was interpreted as showing several pulmonary emboli in the left lung and a peripheral pulmonary infiltrate in the same area.
Symptomatic Pulmonary emboli after pacemaker implantation are uncommon.One study using V/Q lung scans demonstrated probable emboli in 15% of a small number of asymptomatic casesI had a repeat pulmonary CT scan following 3 months of apixaban which was normal .
Six years later my pacemaker battery was nearly end of service and I had a pacemaker replacement. No post op complications occurred this time.
In 2006 ,Rafael Barba-Pichardo et al from Spain published a series of cases of HBP which included a single case of using the His Bundle to pace a patient with heart failure in whom a LV vein could be assessed. This appears to be first case report of HB paced CRT/
In 2010 DL Lustgarten et al accomplished direct His pacing in 10 patients who were candidates for Biv pacing. ( Lustgarten Dl Electrical resynchronization induced by direct his bundle pacing ..Heart Rhythm 7 , 2010 p 15
In 2017 Rodney Tung from Chicago and Kalyanam Shivkumar from UCLAA (2) reported a series of 21 patients in a study the purpose of which to assess the feasibility of a His-bundle lead for CRT in place of the coronary sinus lead.
1)Barba-Pichardo, R et al , Permanent His Bundle Pacing in patients with infra-Hisian atrioventricular block. Revista Espanola de cardiologia, vol 59m553-558
2)Ajijola,OA et al Permanent HIs-Bundle pacing for cardiac resynchronization :initial feasibility study in lieu of left ventricular lead.Heart Rhythm2017,sept 14 (9) 1353-1361
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