So far, we’ve seen a large, flabby heart that doesn’t know how to fill itself, and another large muscular heart that didn’t know when to stop hitting the gym. (Links to the articles - Dilated Cardiomyopathy & Hypertrophic Cardiomyopathy

Next, we’ll take a look at a heart that just doesn’t want to be compliant.

Compliance is a term we looked at in the previous articles, which indicates the ability of the ventricles to accept blood during diastole. In Restrictive Cardiomyopathy (RCM), the compliance of the myocardium is drastically reduced usually due to fibrosis. It can often be confused with HCM or even pericarditis. 

Now why does this occur? 

Amyloid deposition, leading to restriction of the myocardium is one cause. Loeffler’s syndrome, where there is an eosinophillic infiltrate in several organs is another cause. Here, eosinophils release major basic protein, which causes necrosis and ultimately scarring of the myocardial tissue. 

Hemochromatosis, sarcoidosis (due to granuloma formation and subsequent fibrosis of the diseased patches), radiation fibrosis and deposition of metabolites from inborn errors of metabolism are other varied causes. 

Even the morphology is varied. Examination of the myocardium would expect diffuse fibrosis and scarring. However, that isn’t always the case. Fibrosis may be patchy and spread out. The ventricles are firm but they are not dilated. Both atria are also affected. 

So how do we find out what’s wrong?
Endomyocardial biopsy will often help us arrive at a conclusive diagnsosis. 

The treatment is aimed at improving the patient’s symptomatic condition. It is similar to that of heart failure- diuretics, vasodilating agents and ACE inhibitors and Angiotensin receptor blocking agents.

If these measures fail, permanent pacemaker implantation or even transplantation may be required.