Left ventricular lead performance in cardiac resynchronization therapy: impact of lead localization and complications.
BACKGROUND
Cardiac resynchronization therapy (CRT) using left ventricular (LV) pacing from the coronary sinus tributary is increasingly and frequently used in patients with severe congestive heart failure. The present study investigates LV lead performance in different anatomic locations.


METHODS
The LV pacing site was defined by bi-plane fluoroscopy. In the left anterior oblique view, the coronary sinus is encircling the mitral ring with the tributaries radiating out like the hands of a watch. Using this clockwise method, Group A had an LV pacing site before 3 o'clock and Group B at or after 3 o'clock. In right anterior oblique view, the LV was divided into three segments: basal, mid-ventricular, and apical.


RESULTS
LV lead implantation was successful in all of 120 consecutive patients. Mean follow-up was 16.7 months. Implantation time decreased from mean 190 to 80 minutes during the period (P = 0.01). The mean LV lead stimulation threshold increased initially and stabilized afterwards. The threshold measured at last follow-up was higher than at implantation (2.3 vs 2.7 microJ, P = 0.04). Useful venograms were obtained in 94 patients. No significant difference in thresholds was observed between Groups A and B. Phrenic nerve stimulation was most commonly seen in Group B (8/70 vs 1/24, P = 0.001).


CONCLUSIONS
Implantation of an LV lead for CRT is possible in patients with congestive heart failure and associated with an acceptable low complication rate. LV lead implantation is associated with a learning curve. At mid-term follow-up, LV lead performance is stable and unrelated to the LV implantation site.
Albertsen
Andi Eie
AE
Department of Cardiology, Aarhus University Hospital (Skejby), Brendstrupgaardsvej, DK-8200 Aarhus N, Denmark. andieie@mail.dk
Nielsen
Jens Cosedis
JC
Pedersen
Anders Kirstein
AK
Hansen
Peter Steen
PS
Jensen
Henrik Kjaerulf
HK
Mortensen
Peter Thomas
PT
D000293:Adolescent; D000328:Adult; D000368:Aged; D000369:Aged, 80 and over; D002648:Child; D002675:Child, Preschool; D017147:Defibrillators, Implantable; D005260:Female; D005500:Follow-Up Studies; D006333:Heart Failure / Q000503:physiopathology* / Q000628:therapy*; D006801:Humans; D008297:Male; D008875:Middle Aged