Activity monitoring in heart failure patients with cardiac resynchronization therapy.
BACKGROUND
Cardiac resynchronization therapy (CRT) improves functional capacity in heart failure patients. This study aimed to prospectively analyze long-term device-based monitoring of physical activity in patients undergoing CRT.


RESULTS
The Activity Log Index (ALI), calculated by CRT devices, represents the percentage of time when acceleration exceeds a threshold and monitors the physical activity. Data from 178 CRT patients (New York Heart Association III 91%, left ventricular ejection fraction 21+/-6%, left ventricular end-diastolic diameter 69+/-9 mm, QRS 159+/-27 ms, sinus rhythm 81%) were retrieved. The ALI increased from a baseline value of 3.6+/-2.0 to 11.2+/-4.6 (p<0.005) 104 weeks after initiation of CRT. A plateau was reached at approximately 12 weeks and thereafter ALI remained stable for up to 2 years. The magnitude of the changes in ALI was similar in patients with different etiologies and underlying rhythms. Despite similar values at baseline, elderly patients (>or=65 years) exhibited significantly lower ALI values than younger patients during the follow-up and at the plateau (9.5+/-4.2 vs 13.3+/-4.8, p<0.001).


CONCLUSIONS
Device-based monitoring of physical activity in CRT patients is feasible. CRT resulted in a large and long-term increase in physical activity.
Kawabata
Mihoko
M
Department of Cardiovascular Medicine, Tokyo Medical and Dental University, Japan. mihoko_kawabata.cvm@tmd.ac.jp
Fantoni
Cecilia
C
Regoli
Francois
F
Raffa
Santi
S
Pastori
Francesca
F
Fratini
Simona
S
Prentice
John
J
Klein
Helmut U
HU
Auricchio
Angelo
A
D000368:Aged; D000375:Aging / Q000502:physiology; D003920:Diabetes Mellitus / Q000503:physiopathology; D005260:Female; D006333:Heart Failure / Q000209:etiology / Q000503:physiopathology* / Q000628:therapy*; D006339:Heart Rate / Q000502:physiology; D006801:Humans; D008297:Male; D008875:Middle Aged; D018670:Monitoring, Ambulatory / Q000295:instrumentation*; D009043:Motor Activity / Q000502:physiology*; D010138:Pacemaker, Artificial; D011446:Prospective Studies; D013318:Stroke Volume / Q000502:physiology