Constrictive pericarditis is a well known mechanical disorder of heart that occurs due to the compression by thickened pericardium .Constrictive pericarditis is the classical cause for severe diastolic dysfunction.
We know , lungs are prone for restrictive disorders due to chest wall , skeletal disorders. Does the heart get mechanically restricted in extreme obesity ?
Not really , one may reason out . Chest wall fat can have little effect on cardiac function but when excess fat accumulates within the layers of heart , it is indeed possible for the fatty layer to impede mechanical filling of heart. This may be considered rare as of now , but many times it is not recognised , as most of the dyspnea in morbid obesity is attributed to some other known factors.
Dyspnea in obestity can due to
- Pulmonary hypoventilation
- Increased MVO2 due to elevated cardiac mass
- Diastolic dysfunction of LV/RV
- Increased demand due to excess BMI.
Now, we have evidence for altered RV hemodynamics due to compressing effect of epicardial fat pad. It may be due to simple mechanical effect of epicardial fat over the distensiblity of RV or occasionally LV. (The distribution of epicardial fat is mainly over the right ventricle or septal areas.)
This paper from Korean circulatory journal succinctly describes this new possibility .
Bed side cardiology continues to bring surprises , it never fails to fascinate us !
Heart is a dynamic organ , has a potential to get restricted by any layer that surrounds it. Constriction by pericardium got huge attention so far .We need to realise , the epicardium which is a part of pericardium has a variable fat depot . It can take a different avatar in an occasional obese individual and exert important hemodynamic impact.
Excess fat is excess load on heart . . . we have to unload it
It is possible , sucking out the epicardial fat in morbid obesity can bring important relief to those patients with unexplained dyspnea . We need to explore this possibility.