Variation Analysis of Sphygmogram to Assess Cardiovascular System Under Meditation

Chuan-Yi Liu; Ching-Chuan Wei; Pei-Chen Lo

Disclosures

Evid Based Complement Alternat Med. 2009;6(1):107-112. 

In This Article

Abstract and Introduction

Abstract

In this article, we studied how meditation affects the characteristicsof the cardiovascular system, mainly based on blood pressurewaveforms (BPW). Four parameters derived from BPW include therising slope (h 1/t 1), normalized height of T wave (h 3/h 1), normalizedheight of V 3 valley (h 4/h 1) and normalized height of D wave(h 5/h 1), where t 1 and hi , i = 1, ... ,5 are quantitative featuresof the BPW waveform pattern. A larger value of h 1/t 1 reflectsbetter heart ejection ability and aorta compliance. A largervalue of h 3/h 1 may infer an arterial system with good elasticity.The decrease (increase) of h 4/h 1 parameter indicates the decrease(increase) of peripheral resistance of vessels. A larger valueof h 5/h 1 indicates better artery elasticity and aortic valvefunction. In comparison with the control group, Zen-meditationpractitioners have more after-meditation h 1/t 1, h 3/h 1 and h 5/h 1increase, with more h 4/h 1 decrease, with statistical significance(P < 0.05). The observation allows us to infer that Zen meditationmay effectively improve relevant characteristics of the cardiovascularsystem.

Introduction

The blood pressure waveform (BPW) of the systemic arterial treeis an important determinative of cardiovascular system performance.This signal originates in the systole and diastole of the heartand conveys such information as blood ejection ability of theheart, elasticity of the artery wall and peripheral resistance,etc.[1]. In examinations of the clinical value of BPW, Hanexplored possible biophysical and pathologic mechanisms of BPWfrom the viewpoint of hemodynamics[2]. Research showed thatBPW analysis is a highly reproducible method and easy to applyto clinical studies. This measure provides important informationabout arterial stiffness and cardio-vascular interactions[3,4].Abnormality in the BPW is linked to various physiologic or pathologicstates such as aging and hypertension[5,6]. Actually, the BPWof the radial artery detected at the wrist is the sphygmographicsignal used in Traditional Chinese Medicine (TCM)[7]. Accordingto theory of the sphygmographic signal, the TCM clinician canidentify the status of the human body and treat the patient.

As more clinical evidence supported the benefits of meditationfor health, about fifty years ago researchers began investigatingthe physiologic phenomena of the human body under meditation.Dillbeck et al.[8] compared the physiologic differences intwo groups of subjects, one under transcendental meditationand the other at rest. Some research found that the training of transcendental meditation could significantly lower the systolic and diastolic blood pressure of hypertensive persons[9,10,11,12].Meditation hereafter became a feasible method to improve hypertension.Hankey,[13] compared Tibetan Buddhist meditation with Transcendental Meditation. He summarized how practicing different meditation techniques influenced hypertension and other physiologic changes.Barnes et al.[14] found that, under meditation, total peripheral resistance decreased and they suggested that was why meditation could decrease or control hypertension. To assess how meditation affects the cardiovascular system, this paper presents a quantitative approach to evaluate variations in BPW before and after meditation sessions.

We measured the blood pressure waveforms of twenty Zen-meditation participants and twenty normal, healthy subjects in the same age range as the participants. According to the clinical experience of TCM professionals, we designed a set of parameters that quantify the waveform patterns of BPW.

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