The Effects of Healthy Aging on Right Ventricular Structure and Biomechanical Properties: A Pilot Study

Abstract

Healthy aging has been associated with alterations in pulmonary vascular and right ventricular (RV) hemodynamics, potentially leading to RV remodeling. Despite the current evidence suggesting an association between aging and alterations in RV function and higher prevalence of pulmonary hypertension in the elderly, limited data exist on age-related differences in RV structure and biomechanics. In this work, we report our preliminary findings on the effects of healthy aging on RV structure, function, and biomechanical properties. Hemodynamic measurements, biaxial mechanical testing, constitutive modeling, and quantitative transmural histological analysis were employed to study two groups of male Sprague-Dawley rats: control (11 weeks) and aging (80 weeks). Aging was associated with increases in RV peak pressures (+17%, p = 0.017), RV contractility (+52%, p = 0.004), and RV wall thickness (+38%, p = 0.001). Longitudinal realignment of RV collagen (16.4°, p = 0.013) and myofibers (14.6°, p = 0.017) were observed with aging, accompanied by transmural cardiomyocyte loss and fibrosis. Aging led to increased RV myofiber stiffness (+141%, p = 0.003), in addition to a bimodal alteration in the biaxial biomechanical properties of the RV free wall, resulting in increased tissue-level stiffness in the low-strain region, while progressing into decreased stiffness at higher strains. Our results demonstrate that healthy aging may modulate RV remodeling via increased peak pressures, cardiomyocyte loss, fibrosis, fiber reorientation, and altered mechanical properties in male Sprague-Dawley rats. Similarities were observed between aging-induced remodeling patterns and those of RV remodeling in pressure overload. These findings may help our understanding of age-related changes in the cardiovascular fitness and response to disease.

Right Ventricle and Epigenetics: A Systematic Review

“…Moreover, the epigenetic underpinnings of various physiological processes affecting the RV, notably during the aging process, are poorly understood, and, consequently, the literature is very limited. For instance, similarly to the LV, aging markedly impairs RV function-this is manifested through reduced systolic and diastolic functions, increased fibrosis, cardiomyocyte death, and stiffness [142][143][144]-yet the molecular drivers of these age-related changes in the RV remain unclear, with no dedicated studies investigating their epigenetic foundations.…”

Ischemic heart disease and cardiac arrhythmia are associated with increased cardiac aging

“…Similarly, the impact of CA on cardiac aging was also partially mediated by reduced diastolic and systolic ventricular volumes, suggesting age-related declines. Yet, our cardiac aging model uncovered further alterations tied to accelerated cardiac aging in this disease group, such as speci c pattern of right heart remodelling [23] and increased textural heterogeneity of the myocardium. This heterogeneity has also been linked with other conditions like diabetes, hypertrophic cardiomyopathy, and ischaemic stroke, likely re ecting common patterns of tissue brosis that may contribute to the genesis of arrhythmia [24] [22] [25].…”

Using Speckle Tracking Analysis, Does Age Affect RV Longitudinal Strain?

“…This could therefore result in modified contraction dynamics, lower global and regional RV systolic strain, and enhanced RV afterload and remodeling. [10,11] in a study by Qu et al (2020) which comprised 150 healthy volunteers divided into three age groups (20-40, 41-60, and 61-80) with a mean age of (49.8±17.3) years. RVFW global and regional longitudinal strain (basal, mid, and apical) were measured using CMR with the aim to look at changes in RVFW-LS related to age and gender.…”