Acute and chronic performance evaluation of a novel epicardial pacing lead placed by percutaneous subxiphoid approach in a XXXX model.

@entity1317 @entity32 @entity235 @entity884
BACKGROUND: Endovascularly implanted leads risk @entity1317 and @entity884 , and can be difficult to locate in desired positions for LV pacing. We evaluated the acute and long-term stability, electric performance and histopathology of a percutaneously placed intrapericardial lead (IPL). METHODS AND RESULTS: Twelve adult mongrel @entity235 underwent defibrillator implants incorporating IPLs. Successful uncomplicated percutaneous implantation of an IPL was achieved in all. Early fluoroscopic shift noted with 3 of 6 of the initial version IPL-1 was not seen with the modified IPL-2. Mean  95% confidence interval bipolar capture threshold at 0.5-ms pulse width for the IPL increased from 0.69  0.14 V at implant to 1.50  0.34 V (P=0.003) at 12 weeks. The 12-week thresholds were higher for IPL compared with right ventricular endocardial leads (0.75  0.33 V; P=0.001) but not different compared with coronary sinus leads (1.33  0.58 V; P=0.994). IPL impedance increased from 742  46    at implant to 1066  207    at 12 weeks (P=0.007). R-wave amplitude at 12 weeks was 8.37  1.52 mV. There was no important phrenic nerve stimulation from IPL pacing. Histopathology in 8 animals showed adequate adhesion of the electrodes or mesh to the epicardium without damage to underlying vasculature. There was no evidence for late pericardial @entity32 or effusion. CONCLUSIONS: The IPL demonstrated adequate stability of position and acceptable electric parameters without @entity32 in this @entity235 model and offers a potential alternative to endocardial pacing leads.
