Pulmonary arterial wave reflections during acute pulmonary hypertension studied with wave intensity analysis

2009 ◽  
Vol 18 ◽  
pp. S282
Author(s):  
Nathan Dwyer ◽  
Ah Chot Yong ◽  
David Kilpatrick
Keyword(s):  
Pulmonary Hypertension ◽  
Wave Intensity ◽  
Intensity Analysis ◽  
Wave Intensity Analysis ◽  
Wave Reflections ◽  
Acute Pulmonary Hypertension ◽  
Pulmonary Arterial

Abstract 16131: Novel Magnetic Resonance Wave Intensity Analysis in Pulmonary Hypertension

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Michael A Quail ◽  
Daniel S Knight ◽  
Jennifer A Steeden ◽  
Liesbeth Taelman ◽  
Shahin Moledina ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Arteries ◽  
Wave Intensity ◽  
Healthy Controls ◽  
Intensity Analysis ◽  
Wave Intensity Analysis ◽  
Resonance Wave ◽  
Golden Angle ◽  
Significant Difference ◽  
Pressure And Velocity Measurements

Background: Pathological pulmonary wave reflections (WR) are a potential hemodynamic biomarker for pulmonary hypertension (PH). WR can be quantified using wave intensity analysis (WIA), typically utilizing simultaneous invasive pressure and velocity measurements. In this study we reformulated WIA to use CMR area and flow to measure reflections non-invasively. We hypothesized that this method could detect differences in WR in PH patients compared to healthy controls and could also differentiate certain PH subtypes. Methods: 20 patients with PH (35% CTEPH), mean age 54years (75% female) and 10 healthy controls, 47years (60% female) were recruited. Branch pulmonary artery (PA) flow volume (Q) and area curves (A) were used to measure wave intensity ( dI ), defined as, dI =[[Unable to Display Character: &#8710;]]Ax[[Unable to Display Character: &#8710;]]Q and dI ± =± c /4 [[[Unable to Display Character: &#8710;]]A± [[Unable to Display Character: &#8710;]]Q/ c ] 2 , where c =wave-speed. Data were acquired using a retrospectively gated, respiratory navigated, golden-angle, 10.5ms temporal resolution, phase-contrast MR sequence. All patients also underwent right heart cardiac catheterization for pressure and vascular resistance (PVR) measurement, median interval 6 days (IQR 2-11days). The presence of proximal clot in CTEPH patients was determined from contemporaneous CT/angiographic data. Results: A backwards-travelling compression wave (BCW) was present in both left and right PAs of all PH patients, but was absent in all controls ( p =6e -8 ). A backwards-travelling expansion/suction wave was present in the 19/20 branch PAs of controls, and only 4/40 PAs in patients ( p < 0.0001). The area under the BCW was associated with a sensitivity of 100% (95% CI 63-100%) and specificity of 91% (95% CI 75-98%) for the presence of clot in the proximal pulmonary arteries of patients with CTEPH. Conclusions: Noninvasive pulmonary WIA accurately delineates pulmonary vascular health and disease. The main findings of this study were: i) There was a significant difference in WIA metrics between patients and controls, in particular, the presence of a BCW was specifically associated with the presence of PH; and ii) The magnitude of the BCW area showed discriminatory capacity for the presence of proximal PA clot in patients with CTEPH. We believe that these results demonstrate that WIA could be used in the non-invasive assessment of PH.

scholarly journals Novel magnetic resonance wave intensity analysis in pulmonary hypertension

2014 ◽  
Vol 16 (S1) ◽  
Author(s):  
Michael A Quail ◽  
Daniel S Knight ◽  
Jennifer A Steeden ◽  
Andrew Taylor ◽  
Vivek Muthurangu
Keyword(s):  
Pulmonary Hypertension ◽  
Magnetic Resonance ◽  
Wave Intensity ◽  
Intensity Analysis ◽  
Wave Intensity Analysis ◽  
Resonance Wave

scholarly journals Noninvasive pulmonary artery wave intensity analysis in pulmonary hypertension

2015 ◽  
Vol 308 (12) ◽  
pp. H1603-H1611 ◽  
Author(s):  
Michael A. Quail ◽  
Daniel S. Knight ◽  
Jennifer A. Steeden ◽  
Liesbeth Taelman ◽  
Shahin Moledina ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Pulmonary Artery ◽  
Left Pulmonary Artery ◽  
Wave Intensity ◽  
Healthy Controls ◽  
Intensity Analysis ◽  
Wave Intensity Analysis ◽  
Pulmonary Vessel ◽  
Golden Angle ◽  
Angiographic Data

Pulmonary wave reflections are a potential hemodynamic biomarker for pulmonary hypertension (PH) and can be analyzed using wave intensity analysis (WIA). In this study we used pulmonary vessel area and flow obtained using cardiac magnetic resonance (CMR) to implement WIA noninvasively. We hypothesized that this method could detect differences in reflections in PH patients compared with healthy controls and could also differentiate certain PH subtypes. Twenty patients with PH (35% CTEPH and 75% female) and 10 healthy controls (60% female) were recruited. Right and left pulmonary artery (LPA and RPA) flow and area curves were acquired using self-gated golden-angle, spiral, phase-contrast CMR with a 10.5-ms temporal resolution. These data were used to perform WIA on patients and controls. The presence of a proximal clot in CTEPH patients was determined from contemporaneous computed tomography/angiographic data. A backwards-traveling compression wave (BCW) was present in both LPA and RPA of all PH patients but was absent in all controls ( P = 6e−8). The area under the BCW was associated with a sensitivity of 100% [95% confidence interval (CI) 63–100%] and specificity of 91% (95% CI 75–98%) for the presence of a clot in the proximal PAs of patients with CTEPH. In conclusion, WIA metrics were significantly different between patients and controls; in particular, the presence of an early BCW was specifically associated with PH. The magnitude of the area under the BCW showed discriminatory capacity for the presence of proximal PA clot in patients with CTEPH. We believe that these results demonstrate that WIA could be used in the noninvasive assessment of PH.

Simultaneous pulmonary trunk and pulmonary arterial wave intensity analysis in fetal lambs: evidence for cyclical, midsystolic pulmonary vasoconstriction

2008 ◽  
Vol 294 (5) ◽  
pp. R1554-R1562 ◽  
Author(s):  
Joseph J. Smolich ◽  
Jonathan P. Mynard ◽  
Daniel J. Penny
Keyword(s):  
Blood Flow ◽  
Pulmonary Artery ◽  
Compression Wave ◽  
Main Pulmonary Artery ◽  
Pulmonary Trunk ◽  
Wave Intensity ◽  
Intensity Analysis ◽  
Wave Intensity Analysis ◽  
Pulmonary Vasoconstriction ◽  
Pulmonary Arterial

The physiological basis of a characteristically low blood flow to the fetal lungs is incompletely understood. To determine the potential role of pulmonary vascular interaction in this phenomenon, simultaneous wave intensity analysis (WIA) was performed in the pulmonary trunk (PT) and left pulmonary artery (LPA) of 10 anesthetized late-gestation fetal sheep instrumented with PT and LPA micromanometer catheters to measure pressure (P) and transit-time flow probes to obtain blood velocity ( U). Studies were performed at rest and during brief complete occlusion of the ductus arteriosus to augment pulmonary vasoconstriction ( n = 4) or main pulmonary artery to abolish wave transmission from the lungs ( n = 3). Wave intensity (d IW) was calculated as the product of the P and U rates of change. Forward and backward components of d IW were determined after calculation of wave speed. PT and LPA WIA displayed an early systolic forward compression wave (FCWis) increasing P and U, and a late systolic forward expansion wave decreasing P and U. However, a marked midsystolic fall in LPA U to near-zero was related to an extremely prominent midsystolic backward compression wave (BCWms) that arose ∼5 cm distal to the LPA, was threefold larger than the PT BCWms ( P < 0.001), of similar size to FCWis at rest ( P > 0.6), larger than FCWis following ductal occlusion ( P < 0.05) and abolished after main pulmonary artery occlusion. These findings suggest that the absence of pulmonary arterial midsystolic forward flow which accompanies a low fetal lung blood flow is due to a BCWms generated in part by cyclical vasoconstriction within the pulmonary microcirculation.

3.4 WAVE INTENSITY ANALYSIS PROVIDES NOVEL INSIGHTS INTO PULMONARY HYPERTENSION

2016 ◽  
Vol 16 (C) ◽  
pp. 51
Author(s):  
Junjing Su ◽  
Charlotte Manisty ◽  
Kim H. Parker ◽  
Soren Mellemkjaer ◽  
Luke Howard ◽  
...  
Keyword(s):  
Pulmonary Hypertension ◽  
Wave Intensity ◽  
Intensity Analysis ◽  
Wave Intensity Analysis

scholarly journals Noninvasive wave intensity analysis predicts functional worsening in children with pulmonary arterial hypertension

2018 ◽  
Vol 315 (4) ◽  
pp. H968-H977 ◽  
Author(s):  
Michal Schäfer ◽  
Neil Wilson ◽  
D. Dunbar Ivy ◽  
Richard Ing ◽  
Steven Abman ◽  
...  
Keyword(s):  
Pulmonary Arterial Hypertension ◽  
Arterial Hypertension ◽  
Wave Intensity ◽  
Vascular Stiffness ◽  
Intensity Analysis ◽  
Wave Intensity Analysis ◽  
Compression Waves ◽  
Control Subjects ◽  
Healthy Control ◽  
Pulmonary Arterial

The purpose of the present study was to characterize pulmonary vascular stiffness using wave intensity analysis (WIA) in children with pulmonary arterial hypertension (PAH), compare the WIA indexes with catheterization- and MRI-derived hemodynamics, and assess the prognostic ability of WIA-derived biomarkers to predict the functional worsening. WIA was performed in children with PAH ( n = 40) and healthy control subjects ( n = 15) from phase-contrast MRI-derived flow and area waveforms in the main pulmonary artery (MPA). From comprehensive WIA spectra, we collected and compared with healthy control subjects forward compression waves (FCW), backward compression waves (BCW), forward decompression waves (FDW), and wave propagation speed ( c-MPA). There was no difference in the magnitude of FCW between PAH and control groups (88 vs. 108 mm5·s−1·ml−1, P = 0.239). The magnitude of BCW was increased in patients with PAH (32 vs. 5 mm5·s−1·ml−1, P < 0.001). There was no difference in magnitude of indexed FDW (32 vs. 28 mm5·s−1·ml−1, P = 0.856). c-MPA was increased in patients with PAH (3.2 vs. 1.6 m/s, P < 0.001). BCW and FCW correlated with mean pulmonary arterial pressure, right ventricular volumes, and ejection fraction. Elevated indexed BCW [heart rate (HR) = 2.91, confidence interval (CI): 1.18–7.55, P = 0.019], reduced indexed FDW (HR = 0.34, CI: 0.11–0.90, P = 0.030), and increased c-MPA (HR = 3.67, CI: 1.47–10.20, P = 0.004) were strongly associated with functional worsening of disease severity. Our results suggest that noninvasively derived biomarkers of pulmonary vascular resistance and stiffness may be helpful for determining prognosis and monitoring disease progression in children with PAH. NEW & NOTEWORTHY Wave intensity analysis (WIA) studies are lacking in children with pulmonary arterial hypertension (PAH) partially because WIA, which is necessary to assess vascular stiffness, requires an invasive pressure-derived waveform along with simultaneous flow measurements. We analyzed vascular stiffness using WIA in children with PAH who underwent phase-contrast MRI and observed significant differences in WIA indexes between patients with PAH and control subjects. Furthermore, WIA indexes were predictive of functional worsening and were associated with standard catheterization measures.

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