title: Estimation of coronary wave intensity analysis using noninvasive techniques and its application to exercise physiology.
abstract: Wave intensity analysis (WIA) has found particular applicability in the coronary circulation where it can quantify traveling waves that accelerate and decelerate blood flow. The most important wave for the regulation of flow is the backward-traveling decompression wave (BDW). Coronary WIA has hitherto always been calculated from invasive measures of pressure and flow. However, recently it has become feasible to obtain estimates of these waveforms noninvasively. In this study we set out to assess the agreement between invasive and noninvasive coronary WIA at rest and measure the effect of exercise. Twenty-two patients (mean age 60) with unobstructed coronaries underwent invasive WIA in the left anterior descending artery (LAD). Immediately afterwards, noninvasive LAD flow and pressure were recorded and WIA calculated from pulsed-wave Doppler coronary flow velocity and central blood pressure waveforms measured using a cuff-based technique. Nine of these patients underwent noninvasive coronary WIA assessment during exercise. A pattern of six waves were observed in both modalities. The BDW was similar between invasive and noninvasive measures [peak: 14.9 ± 7.8 vs. -13.8 ± 7.1 × 10(4) W·m(-2)·s(-2), concordance correlation coefficient (CCC): 0.73, P < 0.01; cumulative: -64.4 ± 32.8 vs. -59.4 ± 34.2 × 10(2) W·m(-2)·s(-1), CCC: 0.66, P < 0.01], but smaller waves were underestimated noninvasively. Increased left ventricular mass correlated with a decreased noninvasive BDW fraction (r = -0.48, P = 0.02). Exercise increased the BDW: at maximum exercise peak BDW was -47.0 ± 29.5 × 10(4) W·m(-2)·s(-2) (P < 0.01 vs. rest) and cumulative BDW -19.2 ± 12.6 × 10(3) W·m(-2)·s(-1) (P < 0.01 vs. rest). The BDW can be measured noninvasively with acceptable reliably potentially simplifying assessments and increasing the applicability of coronary WIA.
authors.affiliation: Imperial College London, London, United Kingdom; c.broyd@imperial.ac.uk.
authors.forename: Christopher J
authors.initials: CJ
authors.lastname: Broyd
authors.affiliation: Imperial College London, London, United Kingdom;
authors.forename: Sukhjinder
authors.initials: S
authors.lastname: Nijjer
authors.affiliation: Imperial College London, London, United Kingdom;
authors.forename: Sayan
authors.initials: S
authors.lastname: Sen
authors.affiliation: Imperial College London, London, United Kingdom;
authors.forename: Ricardo
authors.initials: R
authors.lastname: Petraco
authors.affiliation: University College London, London, United Kingdom.
authors.forename: Siana
authors.initials: S
authors.lastname: Jones
authors.affiliation: Imperial College London, London, United Kingdom;
authors.forename: Rasha
authors.initials: R
authors.lastname: Al-Lamee
authors.affiliation: Imperial College London, London, United Kingdom;
authors.forename: Nicolas
authors.initials: N
authors.lastname: Foin
authors.affiliation: Imperial College London National Health Service Trust, London, United Kingdom; and.
authors.forename: Mahmud
authors.initials: M
authors.lastname: Al-Bustami
authors.affiliation: Imperial College London National Health Service Trust, London, United Kingdom; and.
authors.forename: Amarjit
authors.initials: A
authors.lastname: Sethi
authors.affiliation: Imperial College London National Health Service Trust, London, United Kingdom; and.
authors.forename: Raffi
authors.initials: R
authors.lastname: Kaprielian
authors.affiliation: Imperial College London National Health Service Trust, London, United Kingdom; and.
authors.forename: Punit
authors.initials: P
authors.lastname: Ramrakha
authors.affiliation: Imperial College London National Health Service Trust, London, United Kingdom; and.
authors.forename: Masood
authors.initials: M
authors.lastname: Khan
authors.affiliation: Imperial College London National Health Service Trust, London, United Kingdom; and.
authors.forename: Iqbal S
authors.initials: IS
authors.lastname: Malik
authors.affiliation: Imperial College London, London, United Kingdom;
authors.forename: Darrel P
authors.initials: DP
authors.lastname: Francis
authors.affiliation: Imperial College London, London, United Kingdom;
authors.forename: Kim
authors.initials: K
authors.lastname: Parker
authors.affiliation: University College London, London, United Kingdom.
authors.forename: Alun D
authors.initials: AD
authors.lastname: Hughes
authors.affiliation: Imperial College London National Health Service Trust, London, United Kingdom; and.
authors.forename: Ghada W
authors.initials: GW
authors.lastname: Mikhail
authors.affiliation: Imperial College London, London, United Kingdom;
authors.forename: Jamil
authors.initials: J
authors.lastname: Mayet
authors.affiliation: Imperial College London, London, United Kingdom;
authors.forename: Justin E
authors.initials: JE
authors.lastname: Davies
mesh_terms: D000368:Aged; D062186:Arterial Pressure; D001783:Blood Flow Velocity; D001795:Blood Pressure Determination / Q000295:instrumentation; D001916:Brachial Artery / Q000502:physiology; D006328:Cardiac Catheterization; D003326:Coronary Circulation; D003331:Coronary Vessels / Q000000981:diagnostic imaging / Q000502:physiology*; D018618:Echocardiography, Doppler, Color; D018619:Echocardiography, Doppler, Pulsed; D015444:Exercise / Q000502:physiology*; D005080:Exercise Test; D005260:Female; D006801:Humans; D008297:Male; D008875:Middle Aged; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D019722:Sphygmomanometers; D013997:Time Factors
keywords: artery; blood flow; hypertrophy; microcirculation; physiology