Wave speed in human coronary arteries is not influenced by microvascular vasodilation: implications for wave intensity analysis

The study of wave propagation at different points in the arterial circulation may provide useful information regarding ventriculoarterial interactions. We describe a number of hemodynamic parameters in the carotid, brachial, and radial arteries of normal subjects by using noninvasive techniques and wave-intensity analysis (WIA). Twenty-one normal adult subjects (14 men and 7 women, mean age 44 ± 6 yr) underwent applanation tonometry and pulsed-wave Doppler studies of the right common carotid, brachial, and radial arteries. After ensemble averaging of the pressure and flow-velocity data, local hydraulic work was determined and a pressure-flow velocity loop was used to determine local wave speed. WIA was then applied to determine the magnitude, timings, and energies of individual waves. At all sites, forward-traveling (S) and backward-traveling (R) compression waves were observed in early systole. In mid- and late systole, forward-traveling expansion waves (X and D) were also seen. Wave speed was significantly higher in the brachial (6.97 ± 0.58 m/s) and radial (6.78 ± 0.62 m/s) arteries compared with the carotid artery (5.40 ± 0.34 m/s; P < 0.05). S-wave energy was greatest in the brachial artery (993.5 ± 87.8 mJ/m2), but R-wave energy was greatest in the radial artery (176.9 ± 19.9 mJ/m2). X-wave energy was significantly higher in the brachial and radial arteries (176.4 ± 32.7 and 163.2 ± 30.5 mJ/m2, respectively) compared with the carotid artery (41.0 ± 9.4 mJ/m2; P < 0.001). WIA illustrates important differences in wave patterns between peripheral arteries and may provide a method for understanding ventriculo-arterial interactions in the time domain.

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The role of wave speed in wave intensity analysis: a sensitivity study in coronary arterial data

Journal of Biomechanics ◽

10.1016/s0021-9290(06)85554-5 ◽

2006 ◽

Vol 39 ◽

pp. S614-S615

Author(s):

J. Aguado-Sierra ◽

J. Davies ◽

J. Mayet ◽

D. Francis ◽

A.D. Hughes ◽

...

Keyword(s):

Wave Speed ◽

Sensitivity Study ◽

Wave Intensity ◽

Intensity Analysis ◽

Wave Intensity Analysis

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Differences in cardiac microcirculatory wave patterns between the proximal left mainstem and proximal right coronary artery

AJP Heart and Circulatory Physiology ◽

10.1152/ajpheart.00510.2008 ◽

2008 ◽

Vol 295 (3) ◽

pp. H1198-H1205 ◽

Cited By ~ 33

Author(s):

Nearchos Hadjiloizou ◽

Justin E. Davies ◽

Iqbal S. Malik ◽

Jazmin Aguado-Sierra ◽

Keith Willson ◽

...

Keyword(s):

Coronary Artery ◽

Flow Velocity ◽

Coronary Arteries ◽

Right Coronary Artery ◽

Coronary Flow ◽

Wave Intensity ◽

Intensity Analysis ◽

Wave Intensity Analysis ◽

Coronary Flow Velocity ◽

Proximal Right Coronary Artery

Despite having almost identical origins and similar perfusion pressures, the flow-velocity waveforms in the left and right coronary arteries are strikingly different. We hypothesized that pressure differences originating from the distal (microcirculatory) bed would account for the differences in the flow-velocity waveform. We used wave intensity analysis to separate and quantify proximal- and distal-originating pressures to study the differences in velocity waveforms. In 20 subjects with unobstructed coronary arteries, sensor-tipped intra-arterial wires were used to measure simultaneous pressure and Doppler velocity in the proximal left main stem (LMS) and proximal right coronary artery (RCA). Proximal- and distal-originating waves were separated using wave intensity analysis, and differences in waves were examined in relation to structural and anatomic differences between the two arteries. Diastolic flow velocity was lower in the RCA than in the LMS (35.1 ± 21.4 vs. 56.4 ± 32.5 cm/s, P < 0.002), and, consequently, the diastolic-to-systolic ratio of peak flow velocity in the RCA was significantly less than in the LMS (1.00 ± 0.32 vs. 1.79 ± 0.48, P < 0.001). This was due to a lower distal-originating suction wave (8.2 ± 6.6 × 103 vs. 16.0 ± 12.2 × 103 W·m−2·s−1, P < 0.01). The suction wave in the LMS correlated positively with left ventricular pressure ( r = 0.6, P < 0.01) and in the RCA with estimated right ventricular systolic pressure ( r = 0.7, P = 0.05) but not with the respective diameter in these arteries. In contrast to the LMS, where coronary flow velocity was predominantly diastolic, in the proximal RCA coronary flow velocity was similar in systole and diastole. This difference was due to a smaller distal-originating suction wave in the RCA, which can be explained by differences in elastance and pressure generated between right and left ventricles.

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The Use of Maximum Entropy to Enhance Wave Intensity Analysis: An Application to Coronary Arteries in Hypertrophic Obstructive Cardiomyopathy

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2021.701267 ◽

2021 ◽

Vol 8 ◽

Author(s):

Nadine Francis ◽

Peter P. Selwanos ◽

Magdi H. Yacoub ◽

Kim H. Parker

Keyword(s):

Maximum Entropy ◽

Coronary Arteries ◽

Hypertrophic Obstructive Cardiomyopathy ◽

Entropy Method ◽

Wave Intensity ◽

Positive Sign ◽

Intensity Analysis ◽

Wave Intensity Analysis ◽

Compression Waves ◽

Naming Convention

Background: Wave intensity analysis is useful for analyzing coronary hemodynamics. Much of its clinical application involves the identification of waves indicated by peaks in the wave intensity and relating their presence or absence to different cardiovascular events. However, the analysis of wave intensity peaks can be problematic because of the associated noise in the measurements. This study shows how wave intensity analysis can be enhanced by using a Maximum Entropy Method (MEM).Methods: We introduce a MEM to differentiate between “peaks” and “background” in wave intensity waveforms. We apply the method to the wave intensity waveforms measured in the left anterior descending coronary artery from 10 Hypertrophic Obstructive Cardiomyopathy (HOCM) and 11 Controls with normal cardiac function. We propose a naming convention for the significant waves and compare them across the cohorts.Results: Using a MEM enhances wave intensity analysis by identifying twice as many significant waves as previous studies. The results are robust when MEM is applied to the log transformed wave intensity data and when all of the measured data are used. Comparing waves across cohorts, we suggest that the absence of a forward expansion wave in HOCM can be taken as an indication of HOCM. Our results also indicate that the backward compression waves in HOCM are significantly larger than in Controls; unlike the forward compression waves where the wave energy in Controls is significantly higher than in HOCM. Comparing the smaller secondary waves revealed by MEM, we find some waves that are present in the majority of Controls and absent in almost all HOCM, and other waves that are present in some HOCM patients but entirely absent in Controls. This suggests some diagnostic utility in the clinical measurement of these waves, which can be a positive sign of HOCM or a subgroup with a particular pathology.Conclusion: The MEM enhances wave intensity analysis by identifying many more significant waves. The method is novel and can be applied to wave intensity analysis in all arteries. As an example, we show how it can be useful in the clinical study of hemodynamics in the coronary arteries in HOCM.

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Usefulness of Proximal Coronary Wave Speed for Wave Intensity Analysis in Diseased Coronary Vessels

Frontiers in Cardiovascular Medicine ◽

10.3389/fcvm.2020.00133 ◽

2020 ◽

Vol 7 ◽

Author(s):

Lorena Casadonte ◽

Jan Baan ◽

Jan J. Piek ◽

Maria Siebes

Keyword(s):

Wave Speed ◽

Coronary Vessels ◽

Wave Intensity ◽

Intensity Analysis ◽

Wave Intensity Analysis

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Potential and limitations of wave intensity analysis in coronary arteries

Medical & Biological Engineering & Computing ◽

10.1007/s11517-009-0448-x ◽

2009 ◽

Vol 47 (2) ◽

pp. 233-239 ◽

Cited By ~ 36

Author(s):

Maria Siebes ◽

Christina Kolyva ◽

Bart-Jan Verhoeff ◽

Jan J. Piek ◽

Jos A. Spaan

Keyword(s):

Coronary Arteries ◽

Wave Intensity ◽

Intensity Analysis ◽

Wave Intensity Analysis

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Angiographic evidence of backward compression wave: systolic compression of septal perforators in a child with hypertrophic cardiomyopathy

Cardiology in the Young ◽

10.1017/s104795112000428x ◽

2020 ◽

pp. 1-2

Author(s):

Rupesh Natarajan ◽

Rebecca Ameduri ◽

Massimo Griselli ◽

Varun Aggarwal

Keyword(s):

Hypertrophic Cardiomyopathy ◽

Coronary Arteries ◽

Compression Wave ◽

Poor Prognosis ◽

Wave Intensity ◽

Compressive Deformation ◽

Intensity Analysis ◽

Wave Intensity Analysis ◽

Angiographic Evidence

Abstract Intracoronary wave intensity analysis in hypertrophic cardiomyopathy has shown a large backward compression wave due to compressive deformation of the intramyocardial coronary arteries in systole. The authors describe the angiographic evidence of this backward compression wave, which has not been described in this physiological context and can be a marker of poor prognosis.

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Non-invasive assessment of ventriculo-arterial coupling using aortic wave intensity analysis combining central blood pressure and phase-contrast cardiovascular magnetic resonance

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez227 ◽

2019 ◽

Vol 21 (7) ◽

pp. 805-813 ◽

Cited By ~ 5

Author(s):

Anish N Bhuva ◽

A D’Silva ◽

C Torlasco ◽

N Nadarajan ◽

S Jones ◽

...

Keyword(s):

Blood Pressure ◽

Compression Wave ◽

Phase Contrast ◽

Wave Speed ◽

Wave Intensity ◽

Intensity Analysis ◽

Wave Intensity Analysis ◽

Reflection Index ◽

Non Invasive ◽

Local Wave

Abstract Background Wave intensity analysis (WIA) in the aorta offers important clinical and mechanistic insight into ventriculo-arterial coupling, but is difficult to measure non-invasively. We performed WIA by combining standard cardiovascular magnetic resonance (CMR) flow-velocity and non-invasive central blood pressure (cBP) waveforms. Methods and results Two hundred and six healthy volunteers (age range 21–73 years, 47% male) underwent sequential phase contrast CMR (Siemens Aera 1.5 T, 1.97 × 1.77 mm2, 9.2 ms temporal resolution) and supra-systolic oscillometric cBP measurement (200 Hz). Velocity (U) and central pressure (P) waveforms were aligned using the waveform foot, and local wave speed was calculated both from the PU-loop (c) and the sum of squares method (cSS). These were compared with CMR transit time derived aortic arch pulse wave velocity (PWVtt). Associations were examined using multivariable regression. The peak intensity of the initial compression wave, backward compression wave, and forward decompression wave were 69.5 ± 28, −6.6 ± 4.2, and 6.2 ± 2.5 × 104 W/m2/cycle2, respectively; reflection index was 0.10 ± 0.06. PWVtt correlated with c or cSS (r = 0.60 and 0.68, respectively, P < 0.01 for both). Increasing age decade and female sex were independently associated with decreased forward compression wave (−8.6 and −20.7 W/m2/cycle2, respectively, P < 0.01) and greater wave reflection index (0.02 and 0.03, respectively, P < 0.001). Conclusion This novel non-invasive technique permits straightforward measurement of wave intensity at scale. Local wave speed showed good agreement with PWVtt, and correlation was stronger using the cSS than the PU-loop. Ageing and female sex were associated with poorer ventriculo-arterial coupling in healthy individuals.

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