Purpose. This study aimed to quantify the deviation of an arterial pulse (pressure wave) from the „golden“ or „divine“ pulse, defined according to the golden ratio φ (phi), and to investigate whether the extent of this deviation is related to the function of autonomic nervous system (ANS) as assessed by 24-hr heart rate variability (HRV).
Methods. Seventy-two healthy subjects underwent 24-hr continuous monitoring of ECG. Applanation tonometry of the radial artery and pulse wave analysis of peripheral and central (mathematically derived) aortic pressure wave forms were performed in all subjects. Time- and frequency domain indices of HRV were computed together with nonlinear dynamic parameters. Two novel indices were computed primarily based on pressure (systolic and diastolic pressure; mmHg) and time (ejection and diastolic durations-intervals; msec) values extracted from the recorded pressure waves.
Results. The new phenotypic, geometrical biomarkers based on the golden ratio (φ) were associated with HRV indices and especially with those computed at the frequency domain. These associations were independent from age, gender, body mass index, mean arterial pressure, pulse pressure and mean 24-hr heart rate.
Conclusion. The new proposed geometrical analysis of the arterial pulse reflects/characterizes specific 24-hr HRV features and is independently related with ANS function. Although the potential pathophysiological, underlying mechanisms of this association can be hardly explained by this study, the application of the golden ratio φ for the analysis of the arterial pulse merits further investigation and may open a new window for the evaluation of cardiovascular risk.
Keywords: arterial pressure, pulse wave analysis, brachial artery, hemodynamics, aorta, blood pressure.
Abbreviations: HRV = Heart rate variability PWA = Pulse Wave Analysis CV = Cardiovascular ApEn = Approximate Entropy DFA = Detrended Fluctuation Analysis SBP = Systolic blood pressure DBP = Diastolic blood pressure PP = Pulse pressure MAP = Mean arterial pressure ED = Ejection duration DD = Diastolic duration ANS = Autonomic nervous system
Address for correspondence:
Biomedical Engineering Unit, 1st University Department of Cardiology,
„Hippokration“ Hospital, Vas. Sophias 114, Athens 115 27, Greece
Tel: 0030 213 2088286, Fax: 0030 213 2088676,