As such, the right ventricle cannot cope as well with higher pressures, and although right ventricular adaptations (hypertrophy and increased contractility of the heart muscle) initially help to preserve stroke volume, ultimately these compensatory mechanisms are insufficient; the right ventricular muscle cannot get enough oxygen to meet its needs and right heart failure follows. As the blood flowing through the lungs decreases, the left side of the heart receives less blood. This blood may also carry less oxygen than normal. Therefore, it becomes harder and harder for the left side of the heart to pump to supply sufficient oxygen to the rest of the body, especially during physical activity. During the end-systolic volume phase of the cardiac cycle, the Gaussian curvature and the mean curvature of right ventricular endocardial wall of PH patients was found to be significantly different as compared to controls.In PVOD (WHO Group I), pulmonary blood vessel narrowing occurs preferentially (though not exclusively) in post-capillary venous blood vessels. PVOD shares several characteristics with PAH, but there are also some important differences, for example differences in prognosis and response to medical therapy.Persistent pulmonary hypertension of the newborn occurs when the circulatory system of a newborn baby fails to adapt to life outside the womb; it is characterized by high resistance to blood flow through the lungs, right-to-left cardiac shunting and severe hypoxemia.Pathogenesis in pulmonary hypertension due to left heart disease (WHO Group II) is completely different in that constriction or damage to the pulmonary blood vessels is not the issue.
Some evidence suggests that there is no significant difference between the survival rates of recipients of mechanical versus biological tricuspid valves.When controlled for severity of TR, tricuspid valve surgery performed on TR patients as considered appropriate is associated with improved outcomes (HR = .74). Prognosis
The prognosis of TR is less favorable for males than females. Survival rates are proportional to TR severity; but even mild TR reduces survival compared to those with no TR. If the TR is due to left heart failure or pulmonary hypertension, prognosis is usually dictated by these conditions, not the TR. Epidemiology
Tricuspid regurgitation is common and is estimated to occur in 65–85% of the population. In The Framingham Heart Study presence of any severity of tricuspid regurgitation, ranging from trace to above moderate was in 82% of men and in 85.7% of women. Mild tricuspid regurgitation tend to be common and benign and in structurally normal tricuspid valve apparatus can be considered a normal variant. Moderate or severe tricuspid regurgitation is usually associated with tricuspid valve leaflet abnormalities and/or possibly annular dilation and is usually pathologic which can lead to irreversible damage of cardiac muscle and worse outcomes due to chronic prolonged right ventricular volume overload.In a study of 595 male elite football players aged 18–38, and 47 sedentary non-athletes, it was found that 58% of the athletes had tricuspid regurgitation vs. 36% in non-athletes. Football players with tricuspid regurgitation had larger tricuspid annulus diameter, compared to athletes without tricuspid regurgitation.