title: Late gadolinium enhancement confined to the right ventricular insertion points in hypertrophic cardiomyopathy: an intermediate stage phenotype?
abstract: OBJECTIVE
  To investigate whether hypertrophic cardiomyopathy (HCM) patients with late gadolinium enhancement (LGE) confined to the right ventricular insertion points (RVIP) differ phenotypically from patients without LGE or intramural LGE in the left ventricle (LV).
  
  
  RESULTS
  Sixty-two HCM patients underwent cardiac magnetic resonance for quantification of LGE (% LV mass) and were classified as group (i) no-LGE (n = 18), group (ii) LGE-RVIP (n = 19), and group (iii) intramural LGE (n = 25). All patients also underwent vasodilator N-13 ammonia PET to quantify myocardial blood flow (MBF) and myocardial flow reserve (MFR), and echocardiography to measure longitudinal LV strain. LGE extent (17 ± 11% vs. 4 ± 4% vs. 0%; P < 0.001) and LV thickness (21.7 ± 3.4 vs. 18.8 ± 3.9 vs. 16.3 ± 2.8 mm; P < 0.001) were significantly greater in group 3, intermediate in group 2, and lower in group 1. In contrast, stress MBF (1.62 ± 0.44 vs. 1.90 ± 0.37 vs. 2.22 ± 0.48 mL/min/g; P < 0.001); MFR (1.92 ± 0.47 vs. 2.15 ± 0.52 vs. 2.71 ± 0.52; P < 0.001), and longitudinal LV strain (-11.4 ± 3.8 vs. -12.6 ± 3.2 vs. -14.4 ± 4.1%; P = 0.04) were lower in group 3, intermediate in group 2, and higher in group 1.
  
  
  CONCLUSIONS
  From an imaging viewpoint, patients with LGE confined to only the RVIP appear to represent an intermediate-stage phenotype between patients with no LGE and intramural LGE in the LV.
authors.affiliation: Department of Cardiology, University of Washington, 1959 NE Pacific Street, PO Box 356422, Seattle, WA 98195, USA Johns Hopkins Medical Institutions, Baltimore, MD, USA pbravo@uw.edu.
authors.forename: Paco E
authors.initials: PE
authors.lastname: Bravo
authors.affiliation: Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Hong-Chang
authors.initials: HC
authors.lastname: Luo
authors.affiliation: Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Iraklis
authors.initials: I
authors.lastname: Pozios
authors.affiliation: Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Stefan L
authors.initials: SL
authors.lastname: Zimmerman
authors.affiliation: Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Celia Pamela
authors.initials: CP
authors.lastname: Corona-Villalobos
authors.affiliation: Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Lars
authors.initials: L
authors.lastname: Sorensen
authors.affiliation: Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Ihab R
authors.initials: IR
authors.lastname: Kamel
authors.affiliation: National Institutes of Health, Bethesda, MD, USA.
authors.forename: David A
authors.initials: DA
authors.lastname: Bluemke
authors.affiliation: Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Richard L
authors.initials: RL
authors.lastname: Wahl
authors.affiliation: Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: M Roselle
authors.initials: MR
authors.lastname: Abraham
authors.affiliation: Johns Hopkins Medical Institutions, Baltimore, MD, USA.
authors.forename: Theodore P
authors.initials: TP
authors.lastname: Abraham
mesh_terms: D055424:Cardiac-Gated Imaging Techniques; D002312:Cardiomyopathy, Hypertrophic / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D003287:Contrast Media; D003326:Coronary Circulation; D004452:Echocardiography; D005260:Female; D019786:Gadolinium DTPA; D006352:Heart Ventricles / Q000000981:diagnostic imaging* / Q000503:physiopathology*; D006801:Humans; D007090:Image Interpretation, Computer-Assisted; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D010641:Phenotype; D049268:Positron-Emission Tomography
chemical_list: D003287:Contrast Media; D019786:Gadolinium DTPA
keywords: CMR; LGE; RV insertion points