When the heart beats, it produces what is generally referred to as a ‘lub-dub’ sound. This sound comes from the shutting of the heart valves when the blood flows through different chambers. Heart valves are gate-like structures between two chambers of the heart that allow a unidirectional flow of blood, thereby preventing the mix up of the blood. Sometimes, the heart produces a swishing or whooshing sound that can be heard with the help of a stethoscope. This sound is known as a murmur, which occurs due to the turbulent flow of blood within the heart. Murmurs may indicate an underlying problem in the heart but sometimes may also occur in a healthy heart.  

Types of heart murmurs

Depending on the severity, heart murmurs are divided into two categories:

• Innocent heart murmurs: In this type, the sounds occur due to the rapid flow of blood through the healthy heart valves. It is harmless as it can occur after any strenuous activity or during pregnancy. Most innocent murmurs occur when the heart muscles are in the state of contraction and therefore, they are categorised as systolic heart murmurs. This type of heart murmur is more common in children and usually disappear when they grow up.
• Abnormal heart murmurs: This type of murmur occurs due to a defect in the heart valve or an abnormality in the heart since birth. This results in regurgitation (backflow) of blood in the heart chambers. Most abnormal heart murmurs occur when the heart muscle relaxes between two heartbeats and therefore, they are classified as diastolic murmurs.

Signs of heart murmurs

Those with an innocent heart murmur may not develop any symptoms. However, the signs of abnormal heart murmur include:

• Chest pain
• Difficulty in breathing
• Persistent cough
• Sweating (even while resting)
• Fainting 
• Dizziness 
• Bluish colouration of the lips and fingertips

The presence of these signs alone does not necessarily mean that the person has a heart murmur. Apart from conducting a physical examination, the doctor may recommend some additional tests such as chest X-ray, electrocardiogram (ECG), echocardiogram, and sometimes cardiac catheterization to confirm heart murmur.

Reasons behind heart murmurs

Abnormal heart murmurs in adults usually occur due to defects in the heart. Some of the reasons for abnormal heart murmurs include:

• Valve regurgitation: This is a valve defect, marked with a backflow of blood due to incomplete closure of a heart valve, resulting in a heart murmur. 
• Valve stenosis: In this defect, the heart valves become stiff and narrow, which prevents them from opening or closing completely.
• Cardiomyopathy: In cardiomyopathy, the heart muscles get thick or weak, which make it difficult for the heart to pump blood normally.

• Septal defect: Defects, such as a hole in the walls (septum) between the upper or lower chambers of the heart can let blood flow through it into different chambers. This extra blood flow can cause a murmur.
• Endocarditis: Endocarditis is an infection that can affect the valves and inner lining of the heart. The infection can hamper the working of the heart valves, resulting in a murmur.

Some conditions that may result in temporary heart murmurs include:

• Rapid growth spurt in children
• Strenuous exercise
• Pregnancy
• High levels of thyroid hormone in the blood (hyperthyroidism)
• Fever
• Anaemia.

Treatment of heart murmurs 

Innocent heart murmurs do not require any treatment. Abnormal heart murmurs can be treated with the help of medications and surgery. 

1. Drug therapy

Medications that are used to treat heart murmurs include:

• Beta-blockers: These are anti-hypertensive medications that help in lowering blood pressure.
• Statins: These medications are given to lower the level of cholesterol.
• Aspirin or warfarin: These are anticoagulants that prevent the formation of blood clots.
• Diuretics: These medications are given to remove extra fluid in the body.

2. Surgery

If the heart murmur occurs due to valve defects, the doctors would perform valve repair or replacement, depending on the case.

• Valve repair: Procedures such as balloon valvuloplasty (widens the valve), annuloplasty (tightens the valve), and valve leaflet repair are used to repair the defects in the heart valve. The doctors may also use a tiny clip-like device that pinches the valve so that it can close completely without leaking the blood backwards.
• Valve replacement: Open heart surgery is done to replace the defective valve. Another less invasive procedure called Transcatheter aortic valve replacement (TAVR) is also done to replace the defective valve.

Conclusion

Heart murmurs can be harmless but sometimes, may indicate underlying valve defects. Therefore, anyone experiencing signs of heart murmurs must consult a cardiologist for further evaluation. People diagnosed with heart murmurs should pre-inform the doctors about their condition before they undergo any procedure such as dental treatments. This would help the doctors take precautionary measures to prevent valve infection.  

Talk to a Cardiologist