title: The effect of obesity on electrocardiographic detection of hypertensive left ventricular hypertrophy: recalibration against cardiac magnetic resonance.
abstract: Electrocardiograph (ECG) criteria for left ventricular hypertrophy (LVH) are a widely used clinical tool. We recalibrated six ECG criteria for LVH against gold-standard cardiac magnetic resonance (CMR) and assessed the impact of obesity. One hundred and fifty consecutive tertiary hypertension clinic referrals for CMR (1.5 T) were reviewed. Patients with cardiac pathology potentially confounding hypertensive LVH were excluded (n=22). The final sample size was 128 (age: 51.0±15.2 years, 48% male). LVH was defined by CMR. From a 12-lead ECG, Sokolow-Lyon voltage and product, Cornell voltage and product, Gubner-Ungerleidger voltage and Romhilt-Estes score were evaluated, blinded to the CMR. ECG diagnostic performance was calculated. LVH by CMR was present in 37% and obesity in 51%. Obesity significantly reduced ECG sensitivity, because of significant attenuation in mean ECG values for Cornell voltage (22.2±5.7 vs 26.4±9.4 mm, P<0.05), Cornell product (2540±942 vs 3023±1185 mm • ms, P<0.05) and for Gubner-Ungerleider voltage (18.2±7.1 vs 23.3±1.2 mm, P<0.05). Obesity also significantly reduced ECG specificity, because of significantly higher prevalence of LV remodeling (no LVH but increased mass-to-volume ratio) in obese subjects without LVH (36% vs 16%, P<0.05), which correlated with higher mean ECG LVH criteria values. Obesity-specific partition values were generated at fixed 95% specificity; Cornell voltage had highest sensitivity in non-obese (56%) and Sokolow-Lyon product in obese patients (24%). Obesity significantly lowers ECG sensitivity at detecting LVH, by attenuating ECG LVH values, and lowers ECG specificity through changes associated with LV remodeling. Our obesity-specific ECG partition values could improve the diagnostic performance in obese patients with hypertension.
authors.affiliation: NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.|School of Physiology and Pharmacology, Bristol Cardiovascular, University of Bristol, Faculty of Medicine and Veterinary Medicine, University of Bristol, Bristol, UK.
authors.forename: J C L
authors.initials: JC
authors.lastname: Rodrigues
authors.affiliation: Severn Postgraduate Medical Education Foundation School, NHS Health Education South West, Bristol, UK.
authors.forename: B
authors.initials: B
authors.lastname: McIntyre
authors.affiliation: NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
authors.forename: A G
authors.initials: AG
authors.lastname: Dastidar
authors.affiliation: NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.|Department of Radiology, Bristol Royal Infirmary, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
authors.forename: S M
authors.initials: SM
authors.lastname: Lyen
authors.affiliation: Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
authors.forename: L E
authors.initials: LE
authors.lastname: Ratcliffe
authors.affiliation: Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
authors.forename: A E
authors.initials: AE
authors.lastname: Burchell
authors.affiliation: School of Physiology and Pharmacology, Bristol Cardiovascular, University of Bristol, Faculty of Medicine and Veterinary Medicine, University of Bristol, Bristol, UK.|Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
authors.forename: E C
authors.initials: EC
authors.lastname: Hart
authors.affiliation: NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
authors.forename: C
authors.initials: C
authors.lastname: Bucciarelli-Ducci
authors.affiliation: NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.|Department of Radiology, Bristol Royal Infirmary, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
authors.forename: M C K
authors.initials: MC
authors.lastname: Hamilton
authors.affiliation: School of Physiology and Pharmacology, Bristol Cardiovascular, University of Bristol, Faculty of Medicine and Veterinary Medicine, University of Bristol, Bristol, UK.|Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
authors.forename: J F R
authors.initials: JF
authors.lastname: Paton
authors.affiliation: School of Physiology and Pharmacology, Bristol Cardiovascular, University of Bristol, Faculty of Medicine and Veterinary Medicine, University of Bristol, Bristol, UK.|Cardionomics Research Group, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
authors.forename: A K
authors.initials: AK
authors.lastname: Nightingale
authors.affiliation: NIHR Bristol Cardiovascular Biomedical Research Unit, Cardiac Magnetic Resonance Department, Bristol Heart Institute, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.|Department of Radiology, Bristol Royal Infirmary, University Hospitals Bristol NHS Foundation Trust, Bristol, UK.
authors.forename: N E
authors.initials: NE
authors.lastname: Manghat
mesh_terms: D000328:Adult; D000368:Aged; D004562:Electrocardiography / Q000592:standards*; D005260:Female; D006801:Humans; D006973:Hypertension / Q000150:complications*; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging* / Q000209:etiology; D008279:Magnetic Resonance Imaging; D008297:Male; D008875:Middle Aged; D009765:Obesity / Q000150:complications*; D011446:Prospective Studies