title: Myocardial velocity gradient reflects the severity of myocardial damage regardless of the presence or absence of mitral regurgitation.
abstract: Complicating mitral regurgitation (MR) apparently enhances left ventricular ejection fraction, thereby leading to the underestimation of myocardial damage by routine echocardiography. We sought to assess the significance of myocardial velocity gradient (MVG) derived from Doppler tissue imaging as an indicator of the severity of myocardial damage in the presence or absence of MR. Peak systolic and diastolic MVG was obtained from 39 participants: 12 healthy participants, 10 patients with dilated cardiomyopathy complicating moderate to severe MR [MR (+) group], and 17 patients with dilated cardiomyopathy without significant MR [MR (-) group]. MVG was compared with standard echocardiographic and Doppler transmitral flow velocity indices. Plasma brain natriuretic peptide levels were measured in all patients. Left ventricular dimension and fractional shortening was similar between MR (+) and MR (-) groups. Plasma brain natriuretic peptide levels were significantly increased in MR (+) group (440 +/- 417 pg/mL) as compared with MR (-) group (122 +/- 107 pg/mL, P <.05). Peak systolic MVG was significantly attenuated in dilated cardiomyopathy group with or without MR [MR (+) group = 1.3 +/- 0.5 seconds(-1), MR (-) group = 2.1 +/- 0.5 seconds(-1), where normal = 4.0 +/- 0.9 seconds(-1), P <.01, respectively]. Peak systolic MVG was further attenuated in MR (+) group than in MR (-) group (P <.01). Plasma brain natriuretic peptide levels were negatively correlated with peak systolic MVG (r = -0.66, P <.0005). Peak diastolic MVG was attenuated in MR (+) and also in MR (-) groups [MR (+) group = -4.5 +/- 2.0 seconds(-1), MR (-) group = -4.4 +/- 1.1 seconds(-1), where normal = -8.7 +/- 2.4 seconds(-1), P <.01, respectively], whereas transmitral flow indices failed to distinguish MR (+) group from normal as a result of pseudonormalization. MVG may reflect the severity of myocardial damage regardless of the presence or absence of complicating MR.
authors.affiliation: Second Department of Internal Medicine, Hiroshima University School of Medicine, Hirsohima, Japan. shimiu.ys@nifty.com
authors.forename: Yoshito
authors.initials: Y
authors.lastname: Shimizu
authors.forename: Masaaki
authors.initials: M
authors.lastname: Uematsu
authors.forename: Noritoshi
authors.initials: N
authors.lastname: Nagaya
authors.forename: Masakazu
authors.initials: M
authors.lastname: Yamagishi
authors.forename: Hideya
authors.initials: H
authors.lastname: Yamamoto
authors.forename: Kunio
authors.initials: K
authors.lastname: Miyatake
authors.forename: Michinori
authors.initials: M
authors.lastname: Imazu
authors.forename: Nobuoki
authors.initials: N
authors.lastname: Kohno
mesh_terms: D000328:Adult; D000368:Aged; D015415:Biomarkers / Q000097:blood; D001783:Blood Flow Velocity / Q000502:physiology*; D002311:Cardiomyopathy, Dilated / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D018618:Echocardiography, Doppler, Color; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging / Q000378:metabolism / Q000503:physiopathology; D006801:Humans; D008297:Male; D008875:Middle Aged; D008944:Mitral Valve Insufficiency / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology*; D009200:Myocardial Contraction / Q000502:physiology*; D020097:Natriuretic Peptide, Brain / Q000097:blood; D015588:Observer Variation; D012720:Severity of Illness Index; D013223:Statistics as Topic; D013318:Stroke Volume / Q000502:physiology; D013997:Time Factors; D018487:Ventricular Dysfunction, Left / Q000097:blood / Q000453:epidemiology / Q000503:physiopathology
chemical_list: D015415:Biomarkers; D020097:Natriuretic Peptide, Brain