Pacemaker-induced transient asynchrony suppresses heart failure progression.
Journal Article (Journal Article)
Uncoordinated contraction from electromechanical delay worsens heart failure pathophysiology and prognosis, but restoring coordination with biventricular pacing, known as cardiac resynchronization therapy (CRT), improves both. However, not every patient qualifies for CRT. We show that heart failure with synchronous contraction is improved by inducing dyssynchrony for 6 hours daily by right ventricular pacing using an intracardiac pacing device, in a process we call pacemaker-induced transient asynchrony (PITA). In dogs with heart failure induced by 6 weeks of atrial tachypacing, PITA (starting on week 3) suppressed progressive cardiac dilation as well as chamber and myocyte dysfunction. PITA enhanced β-adrenergic responsiveness in vivo and normalized it in myocytes. Myofilament calcium response declined in dogs with synchronous heart failure, which was accompanied by sarcomere disarray and generation of myofibers with severely reduced function, and these changes were absent in PITA-treated hearts. The benefits of PITA were not replicated when the same number of right ventricular paced beats was randomly distributed throughout the day, indicating that continuity of dyssynchrony exposure is necessary to trigger the beneficial biological response upon resynchronization. These results suggest that PITA could bring the benefits of CRT to the many heart failure patients with synchronous contraction who are not CRT candidates.
Full Text
Duke Authors
Cited Authors
- Kirk, JA; Chakir, K; Lee, KH; Karst, E; Holewinski, RJ; Pironti, G; Tunin, RS; Pozios, I; Abraham, TP; de Tombe, P; Rockman, HA; Van Eyk, JE; Craig, R; Farazi, TG; Kass, DA
Published Date
- December 23, 2015
Published In
Volume / Issue
- 7 / 319
Start / End Page
- 319ra207 -
PubMed ID
- 26702095
Pubmed Central ID
- PMC4858435
Electronic International Standard Serial Number (EISSN)
- 1946-6242
Digital Object Identifier (DOI)
- 10.1126/scitranslmed.aad2899
Language
- eng
Conference Location
- United States