Pulmonary Arterial Resistance: Noninvasive Measurement with Indexes of Pulmonary Flow Estimated at Velocity-encoded MR Imaging—Preliminary Experience

Introduction: Cor Pulmonale or right ventricular (RV) dysfunction due to pulmonary disease is an expected complication of COPD resulting from increased afterload mediated by hypoxic pulmonary vasoconstriction as well as the destruction of the pulmonary vascular bed. Early detection of elevated RV afterload has been previously demonstrated by visualization of abnormal flow patterns in the proximal pulmonary arteries. Prior quantitative analysis of helicity in the pulmonary arteries of pulmonary hypertension patients has demonstrated a strong association between helicity and increased RV afterload. Hypothesis: Patients with COPD will have abnormal pulmonary flow as evaluated by 4D-Flow MRI and associated with RV function and pulmonary arterial stiffness. Methods: Patients with COPD (n=15) (65yrs ± 6) and controls (n=10) (58yrs ± 9) underwent 4D-Flow MRI to calculate helicity (Figure 1A). The helicity was calculated in 2 segments: 1) the main pulmonary artery (MPA) and 2) along the RV outflow tract (RVOT) - MPA axis. Main pulmonary arterial stiffness was measured using the relative area change (RAC). Results: COPD patients had decreased helicity relative to healthy controls in the MPA (19.4±7.8 vs 32.8±15.9 s -2 , P=0.007) (Figure 1B). Additionally, COPD patients had reduced helicity along the RVOT-MPA axis (33.2±9.0 vs 43.5±8.3 s -2 , P=0.010). The helicity measured in the MPA was associated with RV end-systolic volume (R=0.59, P = 0.002), RVEF (R=0.631, P<0.001), RAC (R=-0.61, P=0.001). e combined helicity along the MPA-RVOT axis was associated with RVEF (R=0.74, P<0.001), RVESV (R=-0.57, P=0.004), and RAC (R=0.42, P=0.005). Conclusion: Patients with COPD show quantitatively abnormal flow hemodynamics, when compared with healthy controls, as assessed by 4D-Flow MRI. A strong association between helicity along the MPA-RV outflow tract axis and RV function suggests that 4D-Flow MRI might be a sensitive tool in evaluating RV - pulmonary arterial coupling in COPD.

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Upstream pressure for systemic to pulmonary flow from bronchial circulation in dogs

Journal of Applied Physiology ◽

10.1152/jappl.1987.63.2.485 ◽

1987 ◽

Vol 63 (2) ◽

pp. 485-491 ◽

Cited By ~ 19

Author(s):

P. G. Agostoni ◽

M. E. Deffebach ◽

W. Kirk ◽

S. Lakshminarayan ◽

J. Butler

Keyword(s):

Arterial Pressure ◽

Venous Pressure ◽

Systemic Arterial Pressure ◽

Driving Pressure ◽

Upstream Site ◽

Bronchial Circulation ◽

Pulmonary Flow ◽

Upstream Pressure ◽

Pulmonary Arterial ◽

Bidirectional Flow

Systemic to pulmonary flow from bronchial circulation, important in perfusing potentially ischemic regions distal to pulmonary vascular obstructions, depends on driving pressure between an upstream site in intrathoracic systemic arterial network and pulmonary vascular bed. The reported increase of pulmonary infarctions in heart failure may be due to a reduction of this driving pressure. We measured upstream element for driving pressure for systemic to pulmonary flow from bronchial circulation by raising pulmonary venous pressure (Ppv) until the systemic to pulmonary flow from bronchial circulation ceased. We assumed that this was the same as upstream pressure when there was flow. Systemic to pulmonary flow from bronchial circulation was measured in left lower lobes (LLL) of 21 anesthetized open-chest dogs from volume of blood that overflowed from pump-perfused (90–110 ml/min) pulmonary vascular circuit of LLL and was corrected by any changes of LLL fluid volume (wt). Systemic to pulmonary flow from bronchial circulation upstream pressure was linearly related to systemic arterial pressure (slope = 0.24, R = 0.845). Increasing Ppv caused a progressive reduction of systemic to pulmonary flow from bronchial circulation, which stopped when Ppv was 44 +/- 6 cmH2O and pulmonary arterial pressure was 46 +/- 7 cmH2O. A further increase in Ppv reversed systemic to pulmonary flow from bronchial circulation with blood flowing back into the dog. When net systemic to pulmonary flow from bronchial circulation by the overflow and weight change technique was zero a small bidirectional flow (3.7 +/- 2.9 ml.min-1 X 100 g dry lobe wt-1) was detected by dispersion of tagged red blood cells that had been injected.(ABSTRACT TRUNCATED AT 250 WORDS)

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Regional and Global Biventricular Function in Pulmonary Arterial Hypertension: A Cardiac MR Imaging Study

Radiology ◽

10.1148/radiol.12111599 ◽

2013 ◽

Vol 266 (1) ◽

pp. 114-122 ◽

Cited By ~ 47

Author(s):

Monda L. Shehata ◽

Ahmed A. Harouni ◽

Jan Skrok ◽

Tamer A. Basha ◽

Danielle Boyce ◽

...

Keyword(s):

Pulmonary Arterial Hypertension ◽

Mr Imaging ◽

Arterial Hypertension ◽

Imaging Study ◽

Cardiac Mr ◽

Biventricular Function ◽

Pulmonary Arterial

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Relationship Between Pulmonary Arterial Resistance and Compliance in Patients with Down Syndrome

Pediatric Cardiology ◽

10.1007/s00246-019-02080-9 ◽

2019 ◽

Vol 40 (4) ◽

pp. 841-847 ◽

Cited By ~ 1

Author(s):

Yuka Iwaya ◽

Jun Muneuchi ◽

Yuka Inoue ◽

Mamie Watanabe ◽

Seigo Okada ◽

...

Keyword(s):

Down Syndrome ◽

Arterial Resistance ◽

Pulmonary Arterial

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The feasibility and clinical implication of tricuspid regurgitant velocity and pulmonary flow acceleration time evaluation for pulmonary pressure assessment during exercise stress echocardiography

European Heart Journal - Cardiovascular Imaging ◽

10.1093/ehjci/jez029 ◽

2019 ◽

Vol 20 (9) ◽

pp. 1027-1034 ◽

Cited By ~ 7

Author(s):

Karina Wierzbowska-Drabik ◽

Eugenio Picano ◽

Eduardo Bossone ◽

Quirino Ciampi ◽

Piotr Lipiec ◽

...

Keyword(s):

Stress Echocardiography ◽

Continuous Wave ◽

Close Correlation ◽

Exercise Stress ◽

Peak Exercise ◽

Acceleration Time ◽

Flow Acceleration ◽

Exercise Stress Echocardiography ◽

Pulmonary Flow ◽

Pulmonary Arterial

Abstract Aims Echocardiography can estimate pulmonary arterial pressure (PAP) from tricuspid regurgitation velocity (TRV) or acceleration time (ACT) of pulmonary flow. We assessed the feasibility of TRV and ACT measurements during exercise stress echocardiography (ESE) and their correlation in all stages of ESE. Methods and results We performed ESE in 102 subjects [mean age 49 ± 17 years, 50 females, 39 healthy, 30 with cardiovascular risk factors, and 33 with pulmonary hypertension (PH)] referred for the assessment of exercise tolerance and ischaemia exclusion. ESE was performed on cycloergometer with the load increasing by 25 W for each 2 min. Assessment of TRV with continuous wave and ACT with pulsed Doppler were attempted in 306 time points: at rest, peak exercise, and recovery. In 20 PH patients we evaluated the correlations of TRV and ACT with invasively measured PAP. The success rate was 183/306 for TRV and 304/306 for ACT (feasibility: 60 vs. 99%, P < 0.0001). There was a close correlation between TRV and ACT: r = 0.787, P < 0.001 and ACT at peak ≤67 ms showed 94% specificity for elevated systolic PAP detection. Moreover, TRV and ACT at peak exercise reflected better that resting data the invasive systolic PAP and mean PAP with r = 0.76, P = 0.0004 and r = −0.67, P = 0.0018, respectively. Conclusion ACT is closely correlated with and substantially more feasible than TRV during ESE and inclusion of both parameters (TRACT approach) expands the possibility of PAP assessment, especially at exercise when TRV feasibility is the lowest but correlation with invasive PAP seems to increase.

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