Ventricular wall stress and wall shear stress homeostasis predicts cardiac remodeling during pregnancy: A modeling study

Abstract

Pregnancy is a unique and dynamic process characterized by significant changes in the maternal cardiovascular system that are required to satisfy the increased maternal and fetal metabolic demands. Profound structural and hemodynamic adaptations occur during healthy pregnancy that allows the mother to maintain healthy hemodynamics and provide an adequate uteroplacental blood circulation to ensure physiological fetal development.Investigating these adaptations is crucial for understanding the physiology of pregnancy and may provide important insights for the management of high-risk pregnancies. However, no previous modeling studies have investigated the maternal cardiac structural changes that occur during gestation. This study, therefore, had two aims. The first was to develop a lumped parameter model of the whole maternal circulation that is suitable for studying global hemodynamics and cardiac function at different stages of gestation. The second was to test the hypothesis that myofiber stress and wall shear stress homeostasis principles can be used to predict cardiac remodeling that occurs during normal pregnancy. Hemodynamics and cardiac variables predicted from simulations with and without controlled cardiac remodeling algorithms were compared and evaluated with reference clinical data. While both models reproduced the hemodynamic variations that arise in pregnancy, importantly, we show that the structural changes that occur with pregnancy could be predicted by assuming invariant homeostatic "target" values of myocardial wall stress and chamber wall shear stress.

Tricuspid annular disjunction can be isolated and even arrhythmogenic. A cardiac magnetic resonance study

“…Further, if the arrhythmogenic focus of MAD, now generally accepted, has any extrapolation for TAD, it would be reasonable to assume that it is an additive arrhythmogenic phenotype. This consideration, if confirmed, would assume its importance both in pathological contexts, such as pulmonary embolism or other diseases associated with acute right-sided overload, and also in particular but very frequent physiological contexts, typically associated with increased wall stress such as endurance exercise (as in our case) [18] and pregnancy [19]. In general, based on the evidence available so far, the prognosis of patients with TVP with or without TAD is still uncertain; therefore, the prognosis of this patient should be considered mainly dependent on the presence of MVP.…”