R-wave amplitude changes with posture and physical activity over time in an insertable cardiac monitor.

Insertable cardiac monitors (ICMs) are accepted tools in cardiac arrhythmia management. Consistent R-wave amplitude (RWA) is essential for optimal detection. Assess RWAs with posture/activities at insertion and at 30 days. Participants (n = 90) with Confirm Rx™ ICM had RWAs measured in different postures (supine, right-side [RS], left-side [LS], sitting, and standing) and defined physical activities (including isometric push [IPUSH] and pull) at 2 time points. ICMs were inserted in 45° to sternum and parasternal orientations. There were significant reductions at insertion with RS, LS, sitting, or standing vs supine (reference position) (all P < .05). At 30 days, significant changes only occurred with LS and sitting (P < .05). Sex had an effect on RWAs, with females having significant variability at insertion (supine vs RS, LS, sitting, standing, and IPUSH; all P < .05). Males showed large RWA interpatient variabilities but minimal differences between positions vs supine. At 30 days, RS, LS, and sitting positions remained significant for females (P < .05), while in males RWAs were higher than at insertion for most postures and activities. The orientation 45° to sternum had consistently higher RWAs vs parasternal orientation at both time points (P < .0001). In females, ICM orientation had no significant effect on RWAs; however, in males the 45° to sternum produced higher RWAs. ICM movement from the insertion site showed no correlation with RWA changes. The mean RWAs were higher at 30 days with less interparticipant and interpostural variability; males had higher RWAs compared to females; 45° to sternum orientation had higher RWAs; and ICM migration from the insertion site did not affect RWAs. © 2022 Heart Rhythm Society.

Citation

Matthew Swale, Sinny Delacroix, Glenn Young, Vincent Paul, Luke McSpadden, Kyungmoo Ryu, David Di Fiore, Maria Santos, Isabel Tan, Andre Conradie, MyNgan Duong, Nisha Schwarz, Stephen Worthley, Stephen Pavia. R-wave amplitude changes with posture and physical activity over time in an insertable cardiac monitor. Cardiovascular digital health journal. 2022 Apr;3(2):80-88

PMID: 35493270

search → result