Pulse wave analysis

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Jafar Al-Said, M.B. ChB. MD. FASN. FACP.Chair of Internal Medicine.

Nephrology and Internal Medicine Consultant.Bahrain Specialist Hospital

PULSE WAVE ANALYSIS, PULSE WAVE VELOCITY AND CENTRAL

BLOOD PRESSURE

EUROPEAN HYPERTENSION EXELLENCE CENTER

BAHRAIN SPECIALIST HOSPITAL

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Scheme• Sphygmomanometer.• Pulse wave hemodynamics.• Incident wave & Reflected wave.• Augmentation pressure. • Central Pressure. • Pulse wave analysis.• Pulse wave Velocity.• How to check the Central pressure.• Evidenced based clinical significance. • PWA and Central BP research data from BSH European HTN

excellence center data. • Conclusion.

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Measurement of the BPKorotkoff sounds of BP measurement.

Discovered By Nocolas Korotkoff 1905.

BP CUFF PICTURE.

en.wikipedia.org/wiki/Korotkoff_souWikipedia

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Transportation in 1900

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Telecommunication and Mail 1900

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CARDIAC CYCLE AND PRESSURE ALTERATION

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Affect of Atherosclerosis on blood flow

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Aorta and Central Arteries

INCIDENT WAVE

REFLECTIVE WAVE

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• Arterial system is a closed system

• Primary wave (blue) travels along the arteries generating reflected waves from bifurcations

• These small reflected waves return to the heart, summing to create a reflected pressure wave as shown in grey, starting even before the end of systole

Figure 2

Physiology - Pressure Wave Reflection at the Heart

19• Central pressure waveform) is the sum of the outgoing and reflected wave (the green wave at

left)

Figure 3

Pressure Wave Reflection at the Heart

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S P

AP

PP

DP

Systolic pressure (SP)

Diastolic pressure (DP)

Central Pulse Pressure (PP)

Augmented pressure (AP)

“measure of the energy “wasted” by the heart due to the reflected wave”

AIx (= AP/PP)

“composite measure of the magnitude of wave reflection and arterial stiffness”

Key Central pressure parameters.

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• With stiffer arteries, the reflected wave arrives back at the heart sooner, adding to (i.e. augmenting) the outgoing wave

• Now there is a very different Central Pressure Waveform (the green wave)

• These features in the waveform can be measured, and have predictive value.Figure 5

Pressure Wave Reflection at the Heart

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Faster reflected time.

Added to systole

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Schematic representation of pulse pressure amplification.

Oliver J J , and Webb D J Arterioscler Thromb Vasc Biol. 2003;23:554-566Copyright © American Heart Association, Inc. All rights reserved.

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Aging and changes in the pulse wave

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ESH guidelines 2013

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In the CAFE study of over 2,000 patients, brachial blood pressure was controlled in both study arms

But the ACE/ CCB arm had up lower central BP and 30% less CV events than the beta blocker arm.

Augmented Pressure was reduced by the ACE/ CCB but not by the beta blocker.

Brachial pressure does not measure arterial stiffness

Central Pressure shows the effects of Drug therapy masked by Brachial Pressure

Williams B et al., Circulation 2006; 113: 1213-25

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PWV

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Final analysis Report

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Patient with CKD IV

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BSH study on PWA and Central BP

Aim:1-Is their a significant difference between the Brachial and Central:

• Systolic.• Dialysis.• Pulse Pressure.• MAP.

2-Independent variables affecting the Augmentation pressure and the Augmentation Pressure Index.

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N = 216

Mean Age (SE): 42 (1).

BMI (SE): 28.8 (0.47).

Gender Male%: 46.8%

BSH study on PWA and Central BP

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Pressure Brachial (SE)

Central (SE)

p

Systolic 136 (1.2) 121.8(1.10 <0.0001Diastolic 83(0.8) 84(0.8) < 0.0001MAP 100.9 (0.8) 100(0.9) < 0.0001Pulse pressure

52.7(1) 37.2(0.8) <0.0001

BSH study on PWA and Central BP

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Regression of the Augmentation Pressure RR 0.42

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Univariate correlation for the Augmentation Pressure

Variables Corr. Coeff. PAge 0.89 0.0001Gender 0.166 0.015BMI 0.327 0.0001Brachial syst. 0.46 0.0001Brachial diast. -0.058 0.39Brachial Pulse Pres. 0.633 0.0001Brachial MAP 0.18 0006Pulse Rate -0.2 0.002Central syst. 0.55 0.0001Central diast. -0.043 0.5Central Pulse Pres. 0.79 0.0001Central MAP 0.216 0.001

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Mulitvariate Regression of the Augmentation Pressure. RR 0.92

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Regression correlation for the Augmentation pressure Index. RR 0.81

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Conclusion• There is a significant difference between Central and Peripheral BP.

• Central BP is different from the peripheral BP.

• It is highly related with CV mortality and morbidity.

• Pulse wave analysis, Pulse wave velocity and Central pressure are additive factors for CV risk assessment.

• Measurement is easy and can be done in our hospital.

• It adds to the cardiovascular risk factor stratification and HTN management.