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Severity of structural and functional right ventricular remodeling depends on training load in an experimental model of endurance exercise
- Source :
- Recercat. Dipósit de la Recerca de Catalunya, instname, Dipòsit Digital de la UB, Universidad de Barcelona
- Publication Year :
- 2017
- Publisher :
- American Physiological Society, 2017.
-
Abstract
- Arrhythmogenic right ventricular (RV) remodeling has been reported in response to regular training, but it remains unclear how exercise intensity affects the presence and extent of such remodeling. We aimed to assess the relationship between RV remodeling and exercise load in a long-term endurance training model. Wistar rats were conditioned to run at moderate (MOD; 45 min, 30 cm/s) or intense (INT; 60 min, 60 cm/s) workloads for 16 wk; sedentary rats served as controls. Cardiac remodeling was assessed with standard echocardiographic and tissue Doppler techniques, sensor-tip pressure catheters, and pressure-volume loop analyses. After MOD training, both ventricles similarly dilated (~16%); the RV apical segment deformation, but not the basal segment deformation, was increased [apical strain rate (SR): −2.9 ± 0.5 vs. −3.3 ± 0.6 s−1, SED vs. MOD]. INT training prompted marked RV dilatation (~26%) but did not further dilate the left ventricle (LV). A reduction in both RV segments' deformation in INT rats (apical SR: −3.3 ± 0.6 vs. −3.0 ± 0.4 s−1 and basal SR: −3.3 ± 0.7 vs. −2.7 ± 0.6 s−1, MOD vs. INT) led to decreased global contractile function (maximal rate of rise of LV pressure: 2.53 ± 0.15 vs. 2.17 ± 0.116 mmHg/ms, MOD vs. INT). Echocardiography and hemodynamics consistently pointed to impaired RV diastolic function in INT rats. LV systolic and diastolic functions remained unchanged in all groups. In conclusion, we showed a biphasic, unbalanced RV remodeling response with increasing doses of exercise: physiological adaptation after MOD training turns adverse with INT training, involving disproportionate RV dilatation, decreased contractility, and impaired diastolic function. Our findings support the existence of an exercise load threshold beyond which cardiac remodeling becomes maladaptive. NEW & NOTEWORTHY Exercise promotes left ventricular eccentric hypertrophy with no changes in systolic or diastolic function in healthy rats. Conversely, right ventricular adaptation to physical activity follows a biphasic, dose-dependent, and segmentary pattern. Moderate exercise promotes a mild systolic function enhancement at the right ventricular apex and more intense exercise impairs systolic and diastolic function.
- Subjects :
- Male
Time Factors
Physiology
Heart diseases
Ventricular Dysfunction, Right
030204 cardiovascular system & hematology
Ventricular Function, Left
Running
Malalties del cor
Fisiologia de l'exercici
0302 clinical medicine
Fibrosis
Medicine
Diastolic function
Cardiomegaly, Exercise-Induced
Training load
Ventricle of heart
Ventricular Remodeling
Models, Cardiovascular
Adaptation, Physiological
Endurance exercise
Cardiology
Right ventricle
Cardiology and Cardiovascular Medicine
medicine.medical_specialty
Heart Ventricles
Physical activity
Exercici
03 medical and health sciences
Ventricles cardíacs
Endurance training
Physiology (medical)
Internal medicine
Animals
Rats, Wistar
Ventricular remodeling
Exercise
Cardiac remodeling
Hypertrophy, Right Ventricular
business.industry
Experimental model
Myocardium
Hemodynamics
Arrhythmias, Cardiac
Eccentric hypertrophy
Exercise physiology
medicine.disease
Echocardiography, Doppler, Color
Disease Models, Animal
Physical Endurance
Ventricular Function, Right
Physical therapy
business
030217 neurology & neurosurgery
Subjects
Details
- Language :
- English
- Database :
- OpenAIRE
- Journal :
- Recercat. Dipósit de la Recerca de Catalunya, instname, Dipòsit Digital de la UB, Universidad de Barcelona
- Accession number :
- edsair.doi.dedup.....471de83785568081bee7c71d013555bd