A feasible approach for direct his-bundle pacing using a new steerable catheter to facilitate precise lead placement.
BACKGROUND
Much clinical evidence has shown that right ventricular (RV) apical pacing is detrimental to left ventricular function. Preservation of the use of the His-Purkinje (H-P) system may be ideal in heart block that is restricted to the AV node, but may be of no benefit when H-P disease exists.


OBJECTIVE
To investigate the feasibility of direct His-bundle pacing (DHBP) using a new system consisting of a steerable catheter and a new 4.1 F screw-in lead.


METHODS
Between May and December 2004, 26 patients (19 male, mean age: 77 +/- 5 years) with a standard pacemaker (PM) indication and preserved His-bundle conduction were enrolled and DHBP was attempted.


RESULTS
DHBP was achieved in 24 patients (92%); two patients were paced in the His area, but the paced QRS morphology and duration were different from the native QRS. The mean time for lead positioning was 19 +/- 17 minutes, the mean fluoroscopy time was 11 +/- 8 minutes, and the total procedure time (skin-to-skin including positioning of a quadripolar diagnostic catheter for His recording) was 75 +/- 18 minutes. In DHBP pacing, the acute pacing threshold was 2.3 +/- 1.0 V at a pulse duration of 0.5 msec, and the sensed potentials were 2.9 +/- 2.0 mV. At a 3-month follow-up examination, the same QRS duration and morphology recorded on implantation were observed in all patients. The pacing threshold was 2.8 +/- 1.4 V, and sensed potentials were 2.5 +/- 1.8 mV; the sensing configuration was changed from bipolar to unipolar in 6 patients to resolve undersensing issues. No major complications were observed.


CONCLUSIONS
This feasibility study shows that DHBP can be accomplished with a new system consisting of a steerable catheter and an active fixation lead in 92% of the patients in whom it was attempted.
Zanon
Francesco
F
Division of Cardiology, Rovigo General Hospital, Rovigo, Italy. franc.zanon@iol.it
Baracca
Enrico
E
Aggio
Silvio
S
Pastore
Gianni
G
Boaretto
Graziano
G
Cardano
Paola
P
Marotta
Tiziana
T
Rigatelli
Gianluca
G
Galasso
Mariapaola
M
Carraro
Mauro
M
Zonzin
Pietro
P
D000368:Aged; D002036:Bundle of His / Q000503:physiopathology*; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D004562:Electrocardiography; D004566:Electrodes; D004867:Equipment Design; D005240:Feasibility Studies; D005260:Female; D005471:Fluoroscopy; D005500:Follow-Up Studies; D006327:Heart Block / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D006801:Humans; D008297:Male; D010138:Pacemaker, Artificial; D012189:Retrospective Studies; D016896:Treatment Outcome