title: Intrafamilial aggregation and heritability of tissue Doppler indexes of left ventricular diastolic function in a group of African descent.
abstract: Although several indexes of left ventricular (LV) diastolic function show heritability, the genetic influence on the tissue Doppler index, E/e' (early transmitral velocity/velocity of myocardial tissue lengthening), an index of LV filling pressures in those of black African descent is currently unknown. Furthermore, whether any genetic influences on E/e' are through an impact of LV remodeling or aortic function is unknown. Intrafamilial aggregation and heritability (SAGE software) of E/e' (echocardiography) were assessed in 129 nuclear families (29 spouse pairs, 216 parent-child pairs, and 113 sibling-sibling pairs) from an urban developing community of black Africans, independent of LV mass index (LVMI), LV relative wall thickness (RWT), central aortic systolic pressure (SBPc), and backward wave pressures (Pb) (applanation tonometry, SphygmoCor software). Independent of confounders including LVMI and RWT, E/e' was correlated in parent-child (r = 0.23; P < .001) and sibling-sibling (r = 0.29; P < .005), but not in spouse (r = 0.13; P = .51) pairs. The relationships between parent-child (r = 0.22; P < .001) and sibling-sibling (r = 0.29; P < .005) pairs persisted with adjustments for SBPc. The relationships between parent-child (r = 0.22; P < .001) and sibling-sibling (r = 0.26; P < .01) pairs also persisted with adjustments for Pb. Independent of confounders including LVMI and RWT, E/e' showed significant heritability (h(2) ± standard error of the mean [SEM] = 0.51 ± 0.11; P < .0001) which similarly persisted with adjustments for SBPc (h(2) ± SEM = 0.50 ± 0.11; P < .0001) and Pb (h(2) ± SEM = 0.49 ± 0.11; P < .0001). In conclusion, in a group of African ancestry, independent of LV remodeling and aortic function, E/e' shows significant intrafamilial aggregation and robust heritability. Hence, genetic factors may play an important role in determining moderate-to-severe LV diastolic dysfunction independent of cardiac remodeling or aortic function in groups of black African ancestry.
authors.affiliation: Cardiovascular Pathophysiology and Genomics Research Unit, Schools of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Vernice R
authors.initials: VR
authors.lastname: Peterson
authors.affiliation: Cardiovascular Pathophysiology and Genomics Research Unit, Schools of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Gavin R
authors.initials: GR
authors.lastname: Norton
authors.affiliation: Department of Nuclear Medicine, School of Clinical Medicine, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Carlos D
authors.initials: CD
authors.lastname: Libhaber
authors.affiliation: Cardiovascular Pathophysiology and Genomics Research Unit, Schools of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Muzi J
authors.initials: MJ
authors.lastname: Maseko
authors.affiliation: Cardiovascular Pathophysiology and Genomics Research Unit, Schools of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa.
authors.forename: Pinhas
authors.initials: P
authors.lastname: Sareli
authors.affiliation: Cardiovascular Pathophysiology and Genomics Research Unit, Schools of Physiology, Faculty of Health Sciences, University of the Witwatersrand, Johannesburg, South Africa. Electronic address: angela.woodiwiss@wits.ac.za.
authors.forename: Angela J
authors.initials: AJ
authors.lastname: Woodiwiss
mesh_terms: D000328:Adult; D000368:Aged; D001011:Aorta; D062186:Arterial Pressure; D044383:Black People / Q000235:genetics*; D003971:Diastole; D004452:Echocardiography; D015150:Echocardiography, Doppler; D005190:Family; D005260:Female; D006352:Heart Ventricles / Q000000981:diagnostic imaging*; D006801:Humans; D006973:Hypertension; D008297:Male; D008875:Middle Aged; D013599:Systole; D018487:Ventricular Dysfunction, Left / Q000000981:diagnostic imaging / Q000235:genetics*; D016277:Ventricular Function, Left / Q000235:genetics*; D020257:Ventricular Remodeling / Q000235:genetics*; D055815:Young Adult
keywords: Aortic function; inheritance; tissue Doppler indexes; transmitral velocity