Moderate exercise training does not worsen left ventricle remodeling and function in untreated severe hypertensive...

Area of Science:

• Cardiovascular Physiology
• Exercise Physiology
• Hypertension Research

Background:

• Hypertension is associated with pathological cardiac hypertrophy and impaired left ventricle (LV) function.
• The effects of exercise training on cardiac adaptations in severe, untreated hypertension require further investigation.

Purpose of the Study:

• To evaluate cardiac adaptations induced by moderate exercise training in normotensive and untreated severe hypertensive rats.
• To assess the impact of exercise on LV morphology, function, and hemodynamics under hypertensive conditions.

Main Methods:

• Four groups of Wistar rats (normotensive sedentary, normotensive trained, hypertensive sedentary, hypertensive trained) were studied over 10 weeks.
• Severe hypertension was induced using a two-kidney, one-clip model.
• Hemodynamics, LV morphology, function (echocardiography), and histology were assessed post-training.

Main Results:

• Severe hypertension induced pathological LV hypertrophy and impaired relaxation.
• Exercise training reduced arterial stiffness in hypertensive rats but did not alter blood pressure.
• Exercise induced eccentric hypertrophy in both normotensive and hypertensive rats; LV hypertrophy index decreased in normotensive rats only.
• LV passive filling improved in trained normotensive rats but not in trained hypertensive rats.

Conclusions:

• Moderate exercise training in untreated severe hypertensive rats induces physiological cardiac hypertrophy without impairing LV systolic function.
• While exercise training reduces arterial stiffness and does not worsen cardiac function in this model, it does not improve LV filling in hypertensive subjects.
• Exercise training's benefits on cardiac structure and function may be limited in the context of severe, untreated hypertension.