Cardiac Remodeling and Its Significance – Verywell

Cardiac remodeling is a term that refers to changes in the hearts size and shape that occur in response to cardiac disease or cardiac damage.

When doctors talk about remodeling, they are usually talking about the left ventricle, though occasionally this term is applied to other cardiac chambers.

When you remodel your house, that is often considered a good thing.

The opposite is true with remodeling of the heart. In general, the greater the degree of ventricular remodeling, the worse the patients outcome is likely to be.

When the left ventricle is damaged -for instance, by amyocardial infarction(heart attack) or by cardiomyopathy-changes often occur in the size and shape of the ventricle. The ventricle tends to become enlarged, its general shape becomes more globular and less elliptical, and the muscular wall of the ventricle often becomes thinner. This remodeling occurs due to mechanical stress on the heart muscle produced by the underlying disease process.

In the early stages of a heart attack, some degree of remodeling can help the ventricle compensate for the damage that has occurred. But if this initial remodeling process continues, and the changes in the size and shape of the ventricle become more exaggerated, cardiac function deteriorates andheart failureensues.

Doctors can assess whether cardiac remodeling is present, and can follow the extent of remodeling over time, with imaging studies that allow them to assess the size, shape, and function of the left ventricle. The most common studies used to measure remodeling areechocardiographyandMRI.

These tests are noninvasive and do not expose the patient to radiation, so they can be repeated as often as necessary.

A useful surrogate measure of remodeling is theleft ventricular ejection fraction (LVEF).Typically, as the size of the ventricle increases, as it becomes more globular in shape, and as the function of the cardiac muscle deteriorates, the LVEF worsens. If remodeling improves, the also LVEF improves.

While it has been known for many decades that cardiac enlargement and a reduced LVEF are bad, the concept of cardiac remodeling has been in common usage among cardiologists only since the 1990s.

This has proven to be a useful concept because it helps to explain why some therapies for heart failure typically improve cardiac survival, and why other therapies do not.

For instance, at one time the use of inotropic drugs was widespread in treating heart failure. These drugs improve the ability of weakened heart muscle to contract more forcefully. While these drugs did improve overall cardiac function, as well as the symptoms of heart failure, they did not improve cardiac survival, and in fact hastened death. Notably, inotropic drugs usually do not improve cardiac remodeling.

In contrast, other kinds of heart failure therapy - for instance,ACE inhibitorsandbeta blockers- do significantly improve not only the symptoms but also the survival of patients with heart failure. These therapies also limit remodeling, and where remodeling has already occurred they can improve the size and shape of the damaged left ventricle.

This ability to improve cardiac remodeling (a trait which cardiologists often refer to as reverse remodeling) is now thought to be extremely important in the therapy of heart failure.

Beta blockers perhaps offer the most striking example of this newer thinking.

Beta blockers tend to reduce the force of contraction of cardiac muscle, and for this reason, for a long time it was thought these drugs ought to be absolutely avoided in anyone with heart failure. But beta blockers also improve the geometry of the left ventricle, and in patients with heart failure it turns out that these drugs reliably reduce the LVEF, improve symptoms, and prolong survival.

The experience with beta blockers now points to the new paradigm that has arisen in the treatment of heart failure - the best treatments for heart failure appear to be those that reduce or reverse ventricular remodeling.

Finding treatments that prevent or reverse remodeling is now a major theme in the treatment of heart failure. Here is a list of therapies for heart failure that improve cardiac remodeling:

Sources:

Cohn JN, Ferrari R, Sharpe N. Cardiac remodeling--concepts and clinical implications: a consensus paper from an international forum on cardiac remodeling. Behalf of an International Forum on Cardiac Remodeling. J Am Coll Cardiol 2000; 35:569.

Hunt SA, Abraham WT, Chin MH, et al. 2009 focused update incorporated into the ACC/AHA 2005 Guidelines for the Diagnosis and Management of HeartFailure in Adults: a report of the American College of Cardiology Foundation/American Heart Association Task Force on Practice Guidelines: developed in collaboration with the International Society for Heart and Lung Transplantation. Circulation 2009; 119:e391.

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Cardiac Remodeling and Its Significance - Verywell