Table 2.

Physiological Features and Corresponding Measurement System

Feature name	Measurement system
Heart rate	Both reference CMR and wearable system
PEP	Wearable system
VET	Wearable system
Timing of AC	Wearable system
Root‐mean‐square power during PEP	Wearable system
Root‐mean‐square power during VET	Wearable system
PEP‐to‐VET ratio	Wearable system
VET‐to‐PEP ratio	Wearable system

AC indicates aortic valve closure; CMR, cardiovascular magnetic resonance imaging; PEP, pre‐ejection period; and VET, ventricular ejection time.