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Exercise Response of the Recipient Atrial Remnant After Orthotopic Cardiac Transplantation: Implications for Recipient Atrial Triggered Pacing
Author(s) -
HOLT NICOLA D.,
BRADY STEVEN,
DARK JOHN H.,
McCOMB JANET M.
Publication year - 1998
Publication title -
pacing and clinical electrophysiology
Language(s) - English
Resource type - Journals
SCImago Journal Rank - 0.686
H-Index - 101
eISSN - 1540-8159
pISSN - 0147-8389
DOI - 10.1111/j.1540-8159.1998.tb01177.x
Subject(s) - chronotropic , medicine , atrial fibrillation , cardiology , atrium (architecture) , transplantation , heart transplantation , sinus rhythm , heart rate , blood pressure
The assumption that the recipient atrial remnant in the cardiac transplant recipient is normal has led to the suggestion that it is an appropriate trigger for permanent pacing in transplant recipients who need pacing or to restore chronotropic competence and/or mechanical synchrony of the composite atrium. We examined the chronotropic response to exercise in 12 orthotopic cardiac transplant recipients (mean age 49 years) at a mean time of 17 months posttransplantation. Recipient and donor atrial rates were noted and compared and chronotropic competence determined. Two of 12 recipient atrial remnants were in atrial fibrillation. Only six of the remaining 10 recipient atria exhibited chronotropic competence. Seven of 10 recipient atria had rates higher than that of the donor. Only four of ten recipient atria in sinus rhythm satisfied both criteria. Two of these had abnormally high atrial responses early into exercise. Of the remaining two, only one recipient atrial remnant demonstrated a ≥ 20% increase in heart rate above that of the donor at peak exercise. Hence only 1 of 12 (8.3%) transplant recipients potentially could benefit from recipient atrial triggered pacing. While recipient atrial triggered pacing is an attractive theoretical concept for restoring chronotropic competence following orthotopic cardiac transplantation, it may rarely be practical because the recipient atrial remnant displays rhythm abnormalities, chronotropic incompetence, and abnormalities in its exercise response.