title: Index of biventricular interdependence calculated using cardiac MRI: a proof of concept study in patients with and without constrictive pericarditis.
abstract: We sought to propose a magnetic resonance (MR) imaging-derived index of biventricular interdependence as a diagnostic parameter to distinguish patients with surgically-confirmed pericardial constriction from those without. Free-breathing real time MR pulse sequences of seventeen subjects with surgically proven constrictive pericarditis and thirty-five patients referred for clinically-indicated cardiac MR examinations but without documented constriction were analyzed using a novel index of biventricular interdependence. Cross-sectional biventricular areas at end diastole using the epicardial surface were traced at the mid left ventricular level at end-inspiration and end-expiration and an index of biventricular interdependence, defined as the ratio of (biventricular end-diastolic area at end-inspiration)/(biventricular end-diastolic area at end-expiration) was calculated for each subject. The mean index for both groups was calculated and results were statistically compared. The index of biventricular interdependence approximated unity (mean index 1.03 ± 0.03 SD) in patients with surgically confirmed pericardial constriction, indicating similar biventricular area at end-inspiration and end-expiration, and was significantly lower than in individuals without constrictive pericarditis (mean index 1.28 ± 0.10 SD; p < 0.0001). The MR-derived index of biventricular interdependence was significantly different between subjects with surgically-confirmed pericardial constriction and subjects where pericardial constraint was not suspected and may serve as a useful metric in the hemodynamic assessment of patients with a potential diagnosis of constrictive pericarditis.
authors: Department of Medicine and Division of Cardiovascular Disease, Mayo Clinic, Rochester, MN 55905, USA. anavekar.nandan@mayo.edu
authors: Nandan S
authors: NS
authors: Anavekar
authors: Benjamin F
authors: BF
authors: Wong
authors: Thomas A
authors: TA
authors: Foley
authors: Kalkidan
authors: K
authors: Bishu
authors: Arunark
authors: A
authors: Kolipaka
authors: Chi Wan
authors: CW
authors: Koo
authors: Masud H
authors: MH
authors: Khandaker
authors: Jae K
authors: JK
authors: Oh
authors: Phillip M
authors: PM
authors: Young
mesh_terms: D000328:Adult; D000368:Aged; D006439:Hemodynamics; D006801:Humans; D008279:Magnetic Resonance Imaging; D008875:Middle Aged; D009206:Myocardium / Q000473:pathology; D015588:Observer Variation; D010494:Pericarditis, Constrictive / Q000175:diagnosis* / Q000473:pathology / Q000503:physiopathology; D011237:Predictive Value of Tests; D015203:Reproducibility of Results; D012189:Retrospective Studies; D013318:Stroke Volume; D013997:Time Factors; D016277:Ventricular Function, Left; D016278:Ventricular Function, Right