Research Study Abstract

Daily Step Count as a Simple Marker of Disease Severity in Hypertrophic Cardiomyopathy

  • Published on Jan 31, 2018

Background: Individuals with hypertrophic cardiomyopathy (HCM) may be asymptomatic or display activity-limiting symptoms. A common cause of symptoms is left ventricular outflow tract obstruction (LVOTO), which may impact the individuals’ ability to undertake physical activity. This study sought to examine daily step count as a potential marker of exercise capacity, which may represent a proxy marker of disease severity in HCM.

Methods: A cross-sectional study of 63 HCM patients was conducted from March to November 2015. Participants wore an ActiGraph GT3X+ (Pensacola, Florida, USA) accelerometer for 7 days. Minutes per day of light, moderate and vigorous physical activity and step count were calculated, and those with LVOTO were compared to those without. Similarly, those with good functional capacity (New York Heart Association; NYHA class I) were compared to those with NYHA class II-IV.

Results: The majority of HCM patients were male (n=45, 71%) with mean age of 48.8±14.9years. Hypertrophic cardiomyopathy patients with history of LVOTO and those NYHA class II-IV took significantly fewer steps per day (LV obstruction: 5527±2370 versus 7027±2095, p=0.01 and NYHA: 5346±1898 versus 6801±2339, p=0.03). No differences were observed across the different intensities of physical activity.

Conclusions: Measurement of daily step count may be a useful and simple tool to determine exercise capacity and provide an indicator of disease severity in individuals with HCM.

Author(s)

  • Sweeting J 1
  • Ingles J 2
  • Ball K 3
  • Semsarian C 4

Institution(s)

  • 1

    Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia.
  • 2

    Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia; Department of Cardiology, Royal Prince Alfred Hospital, Sydney, NSW, Australia.
  • 3

    Centre for Physical Activity and Nutrition Research, Deakin University, Melbourne, Vic, Australia.
  • 4

    Agnes Ginges Centre for Molecular Cardiology, Centenary Institute, Sydney, NSW, Australia; Sydney Medical School, University of Sydney, Sydney, NSW, Australia; Department of Cardiology, Royal Prince Alfred Hospital, Sydney, NSW, Australia. Electronic address: c.semsarian@centenary.org.au.

Journal

Heart, Lung and Circulation

Categories

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