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 .
Seasonal variation of daily physical activity in individuals with heart failure
Background Previous studies indicate that seasonal variation affects daily physical activity ( PA ) , but none have investigated this relationship in individuals with heart failure ( HF ) who also have implanted cardioverter defibrillators and cardiac resynchronization therapy ( ICD/CRT ) devices . The purpose of the present study was to determine if seasonal variation in temperature affects daily PA in patients with HF and ICD/CRTs . Patients and methods Secondary analysis of data from 16 subjects with HF and Medtronic ® ICD/CRT devices enrolled in a r and omized trial investigating interventions to improve daily PA . Due to the rolling study enrollment , daily PA data for all subjects were not available for the entire time frame and were divided into two groups . Determination of seasonal variation of daily PA was determined using visual analysis of daily PA plotted with average temperature , autocorrelation , visual analysis of seasonal subseries plots and boxplot analysis , as well as Wilcoxon signed-rank tests . Results Subjects 1 - 8 demonstrated the greatest differences in daily PA during periods of seasonal transition whereas subjects 9 - 16 demonstrated the greatest variation in daily PA with greatest seasonal temperature difference . Wilcoxon signed-rank testing of the lowest and highest months for daily PA revealed median differences of 0.30 ( p = 0.050 ) and 0.36 hours ( p = 0.036 ) for subjects 1 - 8 and 9 - 16 , with effect sizes of 0.69 and 0.74 , respectively . Conclusions Seasonal variation in mean temperature appears to affect daily PA in individuals with HF and ICD/CRT devices by a magnitude of 0.30 - 0.36 hours , which may need to be accounted for in future research investigating interventions to improve daily PA
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 .