Impaired heart rate response to exercise in adult patients with a systemic right ventricle or univentricular circulation: Prevalence, relation to exercise, and potential therapeutic implications

Diller, Gerhard-Paul; Okonko, Darlington O.; Uebing, Anselm; Dimopoulos, Konstantinos; Bayne, Stephanie; Sutton, Richard; Francis, Darrel P.; Gatzoulis, Michael A.

doi:10.1016/j.ijcard.2008.01.032

« Previous Next »International Journal of Cardiology
Volume 134, Issue 1 , Pages 59-66, 1 May 2009

Impaired heart rate response to exercise in adult patients with a systemic right ventricle or univentricular circulation: Prevalence, relation to exercise, and potential therapeutic implications

Gerhard-Paul Diller
- Adult Congenital Heart Program, Department of Cardiology, Royal Brompton, Hospital, Sydney Street, London, UK
- National Heart and Lung Institute, Imperial College of Science and Medicine, London, UK
- Corresponding author. Adult Congenital Heart Disease Program, Royal Brompton Hospital, Sydney Street, SW3 6NP London, UK. Tel.: +44 207 351 8513; fax: +44 207 351 8733.
Darlington O. Okonko
- National Heart and Lung Institute, Imperial College of Science and Medicine, London, UK
Anselm Uebing
- Adult Congenital Heart Program, Department of Cardiology, Royal Brompton, Hospital, Sydney Street, London, UK
Konstantinos Dimopoulos
- Adult Congenital Heart Program, Department of Cardiology, Royal Brompton, Hospital, Sydney Street, London, UK
Stephanie Bayne
- Adult Congenital Heart Program, Department of Cardiology, Royal Brompton, Hospital, Sydney Street, London, UK
Richard Sutton
- Department of Pacing, Royal Brompton Hospital, Sydney Street, London, UK
Darrel P. Francis
- International Centre for Circulatory Health, Imperial College of Science and Medicine, London, UK
Michael A. Gatzoulis
- Adult Congenital Heart Program, Department of Cardiology, Royal Brompton, Hospital, Sydney Street, London, UK
- National Heart and Lung Institute, Imperial College of Science and Medicine, London, UK

Received 8 May 2007; received in revised form 15 October 2007; accepted 14 January 2008. published online 21 May 2008.

Abstract

Introduction

Exercise limitation is common in patients with a systemic right ventricle or univentricular circulation and may be related to chronotropic incompetence (CI). We aimed to investigate the association of CI with exercise capacity, and evaluate whether CI is causally related to exercise intolerance.

Patients and methods

Cardiopulmonary exercise tests were performed in patients with a systemic right ventricle (n=32) or univentricular circulation (n=32). CI was defined as the inability to achieve 80% of age predicted maximal heart rate reserve ([peak heart rate-resting heart rate]/[220−age−resting heart rate]). The linearity of the relation between oxygen consumption (VO₂) and heart rate (oxygen pulse) was assessed visually and separately quantified by calculating the quadratic regression coefficient (describing departure from linearity).

Results

The prevalence of CI was 59% and 84% in patients with a systemic right ventricle or univentricular circulation, respectively. Patients with CI had a lower peak VO₂ (19.8±5.5 vs. 24.6±6.8 ml/kg/min, P=0.005), and shorter exercise duration (587±165 vs. 749±176 s, P=0.001) than those without CI. Oxygen pulse kinetics suggested exercise limitation due to CI in 8 of 43 patients (19%). In contrast, 13 of 43 patients (30%) had oxygen pulse kinetics suggestive of exercise limitation due to ventricular dysfunction or cyanosis.

Discussion

Chronotropic incompetence is common and associated with exercise limitation in patients with a systemic right ventricle or univentricular circulation. Visual or mathematical assessment of oxygen pulse kinetics identifies patients in whom an attenuated heart-rate response is responsible for poor exercise capacity and may have therapeutic implications.

Keywords: Adult congenital heart disease, Chronotropic incompetence, Exercise capacity