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Assessment of the Extravascular Implantable Defibrillator: Feasibility of Substernal Ventricular Pacing
Author(s) -
BROUWER TOM F.,
SMEDING LONNEKE,
BERGER WOUTER R.,
DRIESSEN ANTOINE H. G.,
GROOT JORIS R.,
WILDE ARTHUR A. M.,
KNOPS REINOUD E.
Publication year - 2017
Publication title -
journal of cardiovascular electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 1.193
H-Index - 138
eISSN - 1540-8167
pISSN - 1045-3873
DOI - 10.1111/jce.13195
Subject(s) - medicine , ventricular pacing , cardiology , cardiac pacing , median sternotomy , pericardium , anesthesia , heart failure
Substernal Pacing in Humans Introduction The objective of this study was to assess feasibility of ventricular pacing and thresholds from within the substernal space to examine a new extravascular ICD configuration with pacing capabilities. Methods In patients undergoing midline sternotomy, a duodecapolar diagnostic pacing catheter was positioned in the substernal space anterior to the pericardium, and a cutaneous patch in left lateral position. Different unipolar and bipolar pacing configurations were assessed. Strength‐duration curves were performed to identify the optimal output, starting at 25 mA with a pulse width of 10 milliseconds. Results Eight patients with mean age 69 ± 9 years were included. In 5, ventricular capture was achieved in ≥1 configuration. The mean bipolar pacing thresholds at PW 10, 5, 3, 1 milliseconds were 12.4 ± 3.7 mA (5 patients), 13.3 ± 5.8 mA (3 patients), 18.3 ± 5.7 mA (3 patients), and 25 ± 0 mA (2 patients), respectively. The 60‐mm electrode spacing was the most successful bipolar configuration. Unipolar pacing was successful in 3 out of 4 patients with mean thresholds of 10 ± 0 mA at 10 milliseconds (3 patients), 15 ± 0 mA at 5 milliseconds (3 patients), 16.7 ± 2.9 mA at 3 milliseconds (3 patients), and 20 ± 7.1 mA at 1 milliseconds (2 patients). Conclusion Ventricular pacing from the substernal space in patients with midline sternotomy is feasible. Closed sternum studies are needed to determine pacing thresholds more accurately.