It sometimes happens that heart valves don’t close properly.

In theory, they’re supposed to direct blood flow forward but when they can’t close, circulating blood mass splashes backward. It’s a condition called “valve insufficiency or regurgitation”.

It’s true that any one valve, or combination of valves, could leak individually or simultaneously in the same patient.

However the most significant leakages in clinical practice are those of the left heart valves: aortic regurgitation and mitral regurgitation.

What is aortic regurgitation?

The aortic valve lies between the left heart ventricle and the aorta. After the heart squeeze or “systole” takes place, the left ventricle relaxes and the aortic valve closes so the blood pumped out would not reflux back in the left ventricle. In aortic regurgitation the valve is incompetent, causing a backward splash.

If the leak is small, one is not likely to have any symptoms. If the backflow becomes severe, the left ventricle has to work harder to pump the extra blood back into the aorta. Symptoms can include dizziness, chest pain with exertion and palpitations.

On the long run the muscle of the left ventricle starts to burn out, or weaken, leading to heart failure. The latter can cause shortness of breath, tiredness, and fluid retention in various parts of the body.

The main causes of aortic regurgitation are:

1. inflammation/infection of the aortic valve from a host of conditions leading to its partial destruction and incompetence

2. abnormal widening of the base of the aorta where the valve sits.

In the second scenario, the root of the aorta becomes abnormally large, hindering the cusps of the aortic valve from snugly meeting and closing.

AR can be diagnosed when your doctor hears a heart murmur on a routine examination if you have no symptoms, and the regurgitation is mild or moderate. It is unusual for AR to reach a severe stage without being detected but if that happens, any or all of the above symptoms could occur. The standard test to establish the diagnosis of AR is a heart ultrasound (or echocardiogram).

The main treatment of advanced AR is a surgical replacement of the defective valve with a mechanical or a tissue valve.

Mechanical valves are made of material that is not likely to react with your body, such as titanium. Biological valves are made from treated animal tissue, such as valves from a pig, a cow or a horse. Medications in the setting of AR have a limited role and are usually used to control blood pressure, which could compound the problem and ease symptoms of heart failure if heart failure develops.

What is mitral insufficiency?

In a normal situation, the mitral valve opens, directing the flow of blood from the “left atrium” to the “left ventricle”. It then closes while the now-full left ventricle squeezes this blood load into the circulation, so almost none of it would splash backward into the left atrium.

When MR is present, blood leaks backwards into the left atrium. This creates two potential sets of symptoms: a reduced amount of blood pumped forward to the body results in fatigue and angina or blood congestion into the left atrium and, with time, into the lungs, causing shortness of breath and fluid build-up.

MR can be mild, moderate or severe. A longstanding severe MR can overtax the heart muscle and weaken it, ultimately leading to heart failure.

Also, if MR is advanced, the dilated left atrium becomes a favourable substrate for atrial fibrillation development.

The most common causes of MR include:

1. mitral valve prolapse: a condition where the valve has defective tissue that with time gets stretched and deformed leading to MR

2. infection, or “endocarditis”, that can destroy the valve

3. dilated heart from a variety of causes, preventing the leaflets of the aortic valve from snugly meeting and closing.

MR diagnosis is usually made by physical exam and echocardiography; the treatment for advanced MR is surgical repair or replacement. An emerging approach of fixing an existing valve or deploying a new valve through the groin, or similar accesses, is being developed.

•Joe Yammine is a cardiologist at Bermuda Hospitals Board. He trained at the State University of New York, Brown University and Brigham and Women’s Hospital. He holds five American Board certifications. He was in academic practice between 2007 and 2014, when he joined BHB. During his career in the US, he was awarded multiple teaching and patients’ care recognition awards. The information herein is not intended as medical advice nor as a substitute for professional medical opinion. Always seek the advice of your physician. You should never delay seeking medical advice, disregard medical advice or discontinue treatment because of any information in this article.