Left ventricular endocardial pacing: a transarterial approach.
BACKGROUND
We tested the feasibility of a new technique of direct left ventricular endocardial lead placement across the aortic valve in a chronic (six month) pig model. The potential for aortic valve damage, systemic embolization, and pacing lead maturation and function within the left ventricle are unknown.


METHODS
Ten minipigs were successfully implanted with a transaortic left ventricular lead (Medtronic CapSureFix, Minneapolis, MN, USA) placed in the left ventricular apex via the carotid artery. Each pig received either a polyurethane (n = 5) or silicone (n = 5) lead. Post implant each pig received clopidogrel and aspirin for seven days. After six months all surviving pigs underwent thorough necropsy.


RESULTS
Each pig had adequate sensing (12.1 +/- 4 mV) and pacing thresholds (0.79 +/- 0.2 @ 0.5 V) at implant. Postoperatively two pigs died of a respiratory illness. One pig died postoperatively due to sepsis. At the six-month follow-up, all surviving pigs (n = 7) were in a healthy state. Of the pigs without dislodgement (n = 5) there was adequate sensing, but a rise in pacing thresholds. Echocardiography revealed a normal ejection fraction and only trace to mild aortic insufficiency in all pigs. Of the seven surviving pigs there were no thromboembolic events noted. One silicone lead was noted to have thrombosis along the lead screw and shaft.


CONCLUSIONS
Direct transaortic placement of a left ventricular lead is feasible. After six months, there was no significant aortic regurgitation and no evidence of thromboembolism despite no anticoagulation. Lead function was acceptable and only one silicone lead (and no polyurethane lead) was noted to have significant thrombosis.
Reinig
Michael
M
Cooper University Hospital/Robert Wood Johnson Medical School, Camden, NJ, USA.
White
Melvin
M
Levine
Marc
M
Cha
Rido
R
Cinel
Ismail
I
Purnachandra
Jasti
J
Goldfarb
Roy
R
Yang
Zhongping
Z
Mulligan
Larry
L
Parrillo
Joseph
J
Gessman
Lawrence
L
D000818:Animals; D001021:Aortic Valve; D002304:Cardiac Pacing, Artificial / Q000379:methods*; D002343:Carotid Artery, Internal; D004195:Disease Models, Animal; D004567:Electrodes, Implanted; D005240:Feasibility Studies; D006333:Heart Failure / Q000503:physiopathology / Q000628:therapy*; D011140:Polyurethanes; D012828:Silicones; D013552:Swine; D013556:Swine, Miniature; D018487:Ventricular Dysfunction, Left / Q000503:physiopathology / Q000628:therapy*
D011140:Polyurethanes; D012828:Silicones