Right coronary artery flow impairment in patients with pulmonary hypertension.
OBJECTIVE
This study investigates whether increased right ventricular (RV) pressure in pulmonary hypertension (PH) impairs right coronary artery (RCA) flow and RV perfusion.


METHODS
In 25 subjects, five patients with idiopathic pulmonary arterial hypertension, nine patients with chronic thromboembolic pulmonary arterial hypertension, and 11 healthy controls, flow of the RCA and left anterior descending (LAD) artery was measured with MR flow quantification.


RESULTS
In PH, RCA peak systolic and mean systolic flow were lower, 1.02 +/- 0.62 mL/s and 0.42 +/- 0.30 mL/s, than peak and mean diastolic flow, 2.99 +/- 1.97 mL/s (P < 0.001) and 1.73 +/- 0.97 mL/s (P < 0.001); a pattern similar to the LAD. In contrast, in controls, RCA peak and mean flow in systole, 1.63 +/- 0.58 mL/s and 0.72 +/- 0.23 mL/s, were comparable to peak and mean flow in diastole, 1.72 +/- 0.48 mL/s and 0.93 +/- 0.28 mL/s (NS). The systolic-to-diastolic flow ratio in the RCA, and mean flow per gram RV tissue, were inversely related to RV mass, R = -0.61 (P = 0.009), and R = -0.73 (P < 0.001) and to RV pressure, R = -0.83 (P < 0.001), and R = -0.57 (P = 0.033).


CONCLUSIONS
Although in controls, RCA flow is similar in systole and diastole, in PH there is systolic flow impediment, which is proportional to RV pressure and mass. In patients with severe RV hypertrophy total mean flow is reduced.
Department of Pulmonary Diseases, Institute for Cardiovascular Research ICaR-VU, VU University Medical Center, De Boelelaan 1117, 1081 HV Amsterdam, Noord-Holland, The Netherlands.
Serge A
SA
van Wolferen
J Tim
JT
Marcus
Nico
N
Westerhof
Marieke D
MD
Spreeuwenberg
Koen M J
KM
Marques
Jean G F
JG
Bronzwaer
Ivo R
IR
Henkens
C Tji-Joong
CT
Gan
Anco
A
Boonstra
Pieter E
PE
Postmus
Anton
A
Vonk-Noordegraaf
D001783:Blood Flow Velocity; D001794:Blood Pressure / Q000502:physiology; D003326:Coronary Circulation / Q000502:physiology*; D023921:Coronary Stenosis / Q000150:complications / Q000503:physiopathology*; D003971:Diastole; D005260:Female; D006801:Humans; D006976:Hypertension, Pulmonary / Q000209:etiology / Q000503:physiopathology*; D017380:Hypertrophy, Right Ventricular / Q000150:complications / Q000503:physiopathology*; D018810:Magnetic Resonance Angiography; D008297:Male; D008875:Middle Aged; D013599:Systole; D018497:Ventricular Dysfunction, Right / Q000150:complications / Q000503:physiopathology*