Wave intensity, an index of ventriculo-arterial interaction, increases in hypertensive subjects but decreases in normotensive subjects during the cold pressor test

Figures

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  Fig. 1. Representative recordings of blood pressure (BP), blood flow velocity (U), and calculated wave intensity (WI) in the common carotid artery, and electrocardiogram (ECG) obtained from a normal subject. WI in a normal subject shows two sharp positive peaks during a cardiac cycle, wave 1 and wave 2, and the ejection period is divided into three phases (initial (E), mid (M), and late ejection (L)) by the two waves

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  Fig. 2. Left: Relation between the percent change in W1 during CPT and age in the normotensive subject group. Right: Relation between the percent change in W1 during CPT and age in the hypertensive subject group. Percent changes are normalized to W1 before CPT

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  Fig. 3. Left: Relation between the percent change in W1 during CPT and β before CPT (resting) in the normotensive subject group. Right: Relation between the percent change in W1 during CPT and β before CPT in the hypertensive subject group. Percent changes are normalized to W1 before CPT

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  Fig. 4. Comparison of the regression lines of the percent changes in W1 during CPT on age for the normotensive group and for the hypertensive group over the age range of 50 to 80. Percent changes are normalized to W1 before CPT