Abstract 18119: Structural and Functional Right Ventricular Remodelling is Related to Training Intensity in an Experimental Model of Endurance Training
Background: a deleterious, potentially arrhythmogenic right ventricle (RV) remodelling has been documented in response to regular training in athletes. However, it is unclear how exercise intensity contributes to RV adverse remodelling.
Aim: Our aim was to evaluate the relationship between RV functional and structural remodelling,and the intensity of exercise in an animal model.
Methods: Thirty-six Wistar rats were conditioned to run daily in a treadmill at a moderate (MOD, 45 min at 30cm/s; estimated 60% VO2max) or vigorous (VIG, 60 min at 60cm/s; estimated 85-90% VO2max) intensity for 16 weeks; Sedentary rats (SED) served as controls. An standard echocardiographic assessment of both ventricles and Tissue Doppler Imaging (TDI) of the RV were performed. Hemodynamics of both ventricles were evaluated with a sensor tip pressure catheter.
Results: After MOD training, both ventricles similarly dilated (roughly 15%). RV function improved as shown by increased RV apical function assessed by TDI (Figure).With VIG training, though, RV disproportionately dilated (in comparison to MOD: 10±13% RV dilation vs 1±12% LV dilation, p<0.05), RV systolic function declined, and RV diastolic function worsened (Figure).The hemodynamic experiments confirmed a decreased RV contractility and impaired relaxation with VIG training (Figure) in comparison to MOD. The LV systolic and diastolic function were unchanged in all groups.
Conclusion: In this animal model we show that exercise intensity critically determines a dual response of the RV. A favourable adaptation of the RV after MOD training turned into disproportionate RV dilatation, decreased contractility and worse diastolic function in the VIG group. Our findings suggest the existence of an intensity threshold beyond which remodelling of the RV becomes maladaptive. Our work provides valuable data to identify athletes at risk of exercise related complications
Author Disclosures: M. Sanz: None. C. Rubies: None. M. Sitges: None. M. Battle: None. B. Bijnens: None. L. Mont: None. J. Brugada: None. E. Guasch: None.
- © 2015 by American Heart Association, Inc.