title: Measurement of total pulmonary arterial compliance using invasive pressure monitoring and MR flow quantification during MR-guided cardiac catheterization.
abstract: Pulmonary hypertensive disease is assessed by quantification of pulmonary vascular resistance. Pulmonary total arterial compliance is also an indicator of pulmonary hypertensive disease. However, because of difficulties in measuring compliance, it is rarely used. We describe a method of measuring pulmonary arterial compliance utilizing magnetic resonance (MR) flow data and invasive pressure measurements. Seventeen patients with suspected pulmonary hypertension or congenital heart disease requiring preoperative assessment underwent MR-guided cardiac catheterization. Invasive manometry was used to measure pulmonary arterial pressure, and phase-contrast MR was used to measure flow at baseline and at 20 ppm nitric oxide (NO). Total arterial compliance was calculated using the pulse pressure method (parameter optimization of the 2-element windkessel model) and the ratio of stroke volume to pulse pressure. There was good agreement between the two estimates of compliance (r = 0.98, P < 0.001). However, there was a systematic bias between the ratio of stroke volume to pulse pressure and the pulse pressure method (bias = 61%, upper level of agreement = 84%, lower level of agreement = 38%). In response to 20 ppm NO, there was a statistically significant fall in resistance, systolic pressure, and pulse pressure. In seven patients, total arterial compliance increased >10% in response to 20 ppm NO. As a population, the increase did not reach statistical significance. There was an inverse relation between compliance and resistance (r = 0.89, P < 0.001) and between compliance and mean pulmonary arterial pressure (r = 0.72, P < 0.001). We have demonstrated the feasibility of quantifying total arterial compliance using an MR method.
authors.affiliation: Cardiac MR Research Group, Division of Imaging Sciences, King's College London, UK.
authors.forename: Vivek
authors.initials: V
authors.lastname: Muthurangu
authors.forename: David
authors.initials: D
authors.lastname: Atkinson
authors.forename: Maxime
authors.initials: M
authors.lastname: Sermesant
authors.forename: Marc E
authors.initials: ME
authors.lastname: Miquel
authors.forename: Sanjeet
authors.initials: S
authors.lastname: Hegde
authors.forename: Robert
authors.initials: R
authors.lastname: Johnson
authors.forename: Rado
authors.initials: R
authors.lastname: Andriantsimiavona
authors.forename: Andrew M
authors.initials: AM
authors.lastname: Taylor
authors.forename: Edward
authors.initials: E
authors.lastname: Baker
authors.forename: Robert
authors.initials: R
authors.lastname: Tulloh
authors.forename: Derek
authors.initials: D
authors.lastname: Hill
authors.forename: Reza S
authors.initials: RS
authors.lastname: Razavi
mesh_terms: D000293:Adolescent; D000328:Adult; D006328:Cardiac Catheterization; D002648:Child; D003187:Compliance; D005240:Feasibility Studies; D006801:Humans; D006976:Hypertension, Pulmonary / Q000175:diagnosis* / Q000503:physiopathology*; D008279:Magnetic Resonance Imaging / Q000379:methods*; D008365:Manometry / Q000379:methods; D011651:Pulmonary Artery / Q000502:physiology*; D011652:Pulmonary Circulation; D011669:Pulmonary Wedge Pressure