CONCLUSIONS Current evidence suggests that D-PA may be useful for assessing physical activity and predicting clinical outcomes in patients with cardiovascular implantable electronic devices when combined with other device parameters .
BACKGROUND  Physical activity  is predictive of cardiovascular outcomes in patients with cardiovascular implantable electronic devices , yet it is not regularly assessed in routine care .
Current-generation cardiovascular implantable electronic devices , however , continuously monitor patient activity through a built-in accelerometer , which provides new opportunities to remotely assess patient activity , detect changes in clinical status , and incorporate these data in risk stratification models .
This review critically examines the literature on device-measured physical activity ( D-PA ) , with a focus on identifying method ological issues that may affect interpretation of study results .
Activity monitoring in heart failure patients with cardiac resynchronization therapy.
BACKGROUND Cardiac resynchronization therapy ( CRT ) improves functional capacity in heart failure patients . This study aim ed to prospect ively analyze long-term device-based monitoring of physical activity in patients undergoing CRT .  METHODS AND 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 result ed in a large and long-term increase in physical activity
CONCLUSIONS Current evidence suggests that D-PA may be useful for assessing physical activity and predicting clinical outcomes in patients with cardiovascular implantable electronic devices when combined with other device parameters .
BACKGROUND  Physical activity  is predictive of cardiovascular outcomes in patients with cardiovascular implantable electronic devices , yet it is not regularly assessed in routine care .
Current-generation cardiovascular implantable electronic devices , however , continuously monitor patient activity through a built-in accelerometer , which provides new opportunities to remotely assess patient activity , detect changes in clinical status , and incorporate these data in risk stratification models .
This review critically examines the literature on device-measured physical activity ( D-PA ) , with a focus on identifying method ological issues that may affect interpretation of study results .