title: Slowed atrial and atrioventricular conduction and depressed HRV in a murine model of hypertrophic cardiomyopathy.
abstract: Hypertrophic cardiomyopathy (HCM) is a common heritable cardiac disorder with diverse clinical outcomes including sudden death, heart failure, and stroke. Depressed heart rate variability (HRV), a measure of cardiac autonomic regulation, has been shown to predict mortality in patients with cardiovascular disease. Cardiac autonomic remodelling in animal models of HCM are not well characterised. This study analysed Gly203Ser cardiac troponin-I transgenic (TG) male mice previously demonstrated to develop hallmarks of HCM by age 21 weeks. 33 mice aged 30 and 50 weeks underwent continuous electrocardiogram (ECG) recording for 30 min under anaesthesia. TG mice demonstrated prolonged P-wave duration (P < 0.001) and PR intervals (P < 0.001) compared to controls. Additionally, TG mice demonstrated depressed standard deviation of RR intervals (SDRR; P < 0.01), coefficient of variation of RR intervals (CVRR; P < 0.001) and standard deviation of heart rate (SDHR; P < 0.001) compared to controls. Additionally, total power was significantly reduced in TG mice (P < 0.05). No significant age-related difference in either strain was observed in ECG or HRV parameters. Mice with HCM developed slowed atrial and atrioventricular conduction and depressed HRV. These changes were conserved with increasing age. This finding may be indicative of atrial and ventricular hypertrophy or dysfunction, and perhaps an indication of worse clinical outcome in heart failure progression in HCM patients.
authors.affiliation: Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and the Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Wei-Wen
authors.initials: WW
authors.lastname: Lim
authors.affiliation: Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and the Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Mathias
authors.initials: M
authors.lastname: Baumert
authors.affiliation: Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and the Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Melissa
authors.initials: M
authors.lastname: Neo
authors.affiliation: Department of Physiology, Maastricht University, Maastricht, The Netherlands.
authors.forename: Pawel
authors.initials: P
authors.lastname: Kuklik
authors.affiliation: Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and the Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Anand N
authors.initials: AN
authors.lastname: Ganesan
authors.affiliation: Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and the Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Dennis H
authors.initials: DH
authors.lastname: Lau
authors.affiliation: Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, Australia and the University of Sydney, Sydney, Australia.
authors.forename: Tatiana
authors.initials: T
authors.lastname: Tsoutsman
authors.affiliation: Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, Australia and the University of Sydney, Sydney, Australia.
authors.forename: Christopher
authors.initials: C
authors.lastname: Semsarian
authors.affiliation: Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and the Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: Prashanthan
authors.initials: P
authors.lastname: Sanders
authors.affiliation: Centre for Heart Rhythm Disorders, South Australian Health and Medical Research Institute (SAHMRI), University of Adelaide and the Royal Adelaide Hospital, Adelaide, Australia.
authors.forename: David A
authors.initials: DA
authors.lastname: Saint
mesh_terms: D000818:Animals; D002312:Cardiomyopathy, Hypertrophic / Q000503:physiopathology*; D004195:Disease Models, Animal; D004562:Electrocardiography; D005260:Female; D006325:Heart Atria / Q000503:physiopathology*; D006329:Heart Conduction System / Q000503:physiopathology*; D006339:Heart Rate; D006352:Heart Ventricles / Q000503:physiopathology*; D007700:Kinetics; D008297:Male; D051379:Mice; D008810:Mice, Inbred C57BL
keywords: electrocardiography; heart rate variability; hypertrophic cardiomyopathy; mice