Skip to main content

Table 1 Factors affecting the information transmission from ECG R wave to PPG pulse wave

From: Pulse rate variability: a new biomarker, not a surrogate for heart rate variability

Physiological measure Anatomical location Conversion of physical property Modulators
Direct Indirect
ECG R wave
Left ventricular muscle Electric excitation
Intraventricular conduction, ventricular activation time, electromechanical coupling Myocardial ischemia, heart diseases
Pre-ejection period
Left ventricle Muscle force
Preload and after-load, contractility, aortic diastolic pressure Respiration, blood pressure, body position and exercise, heart failure (alternating pulse)
Aortic pressure elevation
Aorta Pressure impulse
Stroke volume, aortic dynamic compliance, intrathoracic pressure Respiration, peripheral resistance
Pulse conduction time
Artery Pressure wave
Internal radius, wall thickness and elasticity, blood density Vasomotor sympathetic activity, endothelial function, blood pressure
Tissue volume
Tissue microvasculature Blood volume
Vascular dynamic compliance, blood flow, venous pressure Location and body position, body and environmental temperature
PPG pulse wave Red cell hemoglobin Light intensity Absorption, scattering, reflection, and transmission; vascular bed volume Local red cell count, hemoglobin content, waveform fiducial point
  1. ECG electrocardiography, PPG Photoplethysmography