What is heart murmur?
A heart murmur is a noise between the heartbeats , caused by changes in the heart’s valves. It is usually heard on a routine physical examination and resembles a murmur in the ear. It is not always pathological, but it can indicate some disease. The breath often disappears on its own.
According to cardiologist Bruno Colontone, “breath is not a disease, but a sign”. There are innocent murmurs, which are not harmful to health and can appear and disappear for no apparent reason, being relatively common in children. Pathological murmurs, on the other hand, may be signs that there is a problem with the individual’s valves. In severe cases, surgery may be required to repair.
To better understand the heart, it is divided into 4 parts: two atria and two ventricles, separated by a septum. Arterial blood circulates in the atrium and right ventricle, while arterial blood flows in the atrium and left ventricle.
Between the atria and ventricles, there are valves, known as the tricuspid valve and mitral valve. They allow normal blood flow in the heart.
In normal circulation, the right atrium receives venous blood, and the left atrium receives arterial blood. At that time, blood passes through the valves, moving it to the ventricles.
The right ventricle sends venous blood to the lung (through the pulmonary valve), to oxygenate the blood. At the same time, the left ventricle sends arterial blood (through the aortic valve) to the arteries.
In other words, there are two important moments in the heart and each one produces a sound in sequence that results from the opening and closing of the valves, resulting in the classic “tum-tum” sound.
At the first moment, the blood passes from the atria to the ventricles, passing through the tricuspid valves and mitral valve, making the first “tum”.
And in the second moment, each ventricle sends the blood, either to the lung (through the pulmonary valve) or to the arteries (through the aortic valve), generating the second “tum”.
The murmur is a noise that we hear between the sound of the “tum-tum”, during the movement of the blood through one of the valves. This is usually the result of some other problem or dysfunction that hinders or alters the normal flow of blood between the valves.
In children, the murmur is relatively common. About 30% to 50% of healthy children may have a benign murmur (also known as an innocent murmur), which can be caused by problems at birth, but not necessarily.
In some cases, it arises naturally, as the child is developing his heart and there is a disproportion of the vessels and the other structures of the organ. The murmur can also appear for no apparent reason. The most normal for such cases is that the condition disappears with age.
A heart with a murmur is not necessarily a sick heart, it just has a blood disorder that may or may not indicate a disease. There are two types of murmurs:
Physiological, benign, or innocent murmur
Very common in children, it has no apparent reason and can disappear on its own after some time. It can also occur in adults, but to a lesser extent.
It can be congenital or acquired over a lifetime and is linked to other heart problems.
Cardiologists usually classify the pitch of the sound from I to VI. In general, grades I to II are usually benign. Grade III to VI murmurs are always pathological, but not necessarily serious. Understand:
- Grade I: Breath almost inaudible;
- Grade II: Weak intensity, but noticeable with some attention;
- Grade III: Easily heard murmur;
- Grade IV: Breath with thrill (palpable in the chest and which is high;
- Grade V: Quivering and very loud murmur that can be heard with the stethoscope slightly away;
- Grade VI: Blast with a tremor and very loud, it may be possible to hear it even with the stethoscope away.
It is important to remember that we can have, for example, grade I and II cases needing surgery, while there are cases in which grades III to VI would not need it. Everything varies from case to case, from patient to patient and the doctor who has the final say on this.
The benign or normal murmur is usually caused by turbulence in the blood flow or some slight abnormality of the valves. This does not have serious negative effects. Often, it may not have a specific cause and tends to go away on its own.
Pathological murmur is more common in adults who had rheumatic fever as children or who have other cardiovascular problems.
In general, the murmur is related to problems such as:
Changes in blood flow
Some circumstances can cause changes in blood flow, which can cause turbulence. These conditions are:
- Physical effort;
Some conditions can affect the valves and cause blowing, such as:
Valve stenosis (narrowing of the valves)
It occurs when one of the valves hardens and fails to open properly, resulting in a narrowing that causes the blood to come out with greater pressure. This whirlwind causes the breath.
The narrowing can occur due to congenital problems at the birth of the child, rheumatic fever or even calcification of the valve due to age.
The nomenclature of the stenosis indicates the affected valve. We call it aortic stenosis when the narrowing occurs in the aortic valve and tricuspid stenosis when it occurs in the tricuspid valve.
Valve failure (or valve regurgitation)
It appears when the valve fails to close completely, allowing some blood to pass in the opposite direction. This causes a whirlwind, which in turn causes the breath.
Changes in the blood path
Congenital malformations (present since birth) cause blood to follow a different path than it should normally do. The main changes are:
Interatrial or interventricular communication
The cardiac septum is a muscle wall that separates the left and right sides of the heart. Sometimes, a hole can originate, causing arterial blood and venous blood to meet, thus causing a problem in the communication between the atria and ventricles.
Tetralogy of Fallot (T4F)
Fallot’s tetralogy is a congenital malformation, which is composed of 4 problems:
- Problem of interventricular communication (as mentioned above, a hole in the septum, which ends up mixing arterial blood with venous blood);
- Misalignment of the aorta to the right;
- Difficulty in the passage of venous blood to the lung;
- Overworking the right ventricle, thus generating an increase in muscle.
The clearest symptom is the presence of a sound or noise more than the classic “tum-tum” that we are used to.
Benign murmurs do not usually have other symptoms. However, as the pathological murmur can be related to other heart diseases, attention should be paid to some possible symptoms. These can indicate heart problems that, perhaps, cause the murmur. Are they:
- Chest pains;
- Excessive sweating;
- Purple tongue;
- Bounced veins;
- Difficulty breathing.
Normally, the murmur is detected in a routine examination by means of auscultation, using a stethoscope. Other tests may be required to determine the cause of the murmur.
The echocardiogram is the most complete exam to detect the presence of any problems that may be causing the murmur, such as leakage and narrowing of the heart valves.
The patient lies on a bed, while the equipment generates images similar to an ultrasound. These images demonstrate well the internal state of the cardiac structures and the speed of the blood flow. Therefore, it is the most suitable and complete exam for patients who have a murmur.
It is a non-invasive test that checks the electrical activity of the patient’s heart. The electrocardiogram does not generate an image, but a graph that allows to check the nervous stimuli in the patient’s heart, allowing to detect general problems in the heart.
As the focus of this exam is on the patient’s neuromuscular system, it is he who will find out if the cause of the murmur is related to a defect in the nerves or muscles.
This exam generates an X-ray image of the thoracic region (chest region), which visualizes possible bone fractures, tumors, as well as other heart problems that may be causing the murmur. In addition, it allows you to monitor the progress of such diseases. It is ideal for detecting problems related to shortness of breath, chest pain or problems related to the esophagus, among others.
As the murmur, in itself, is not a disease, has no cure and is not the focus of the treatment.
In many cases, the murmur disappears on its own over time. However, with pathological murmur, disappearance occurs only when related diseases are treated.
Each case of murmur may require specific treatment depending on the associated disease, which must be diagnosed by a cardiologist.
In simple cases, the problem can be treated with medications. However, in more severe cases, surgical intervention may be necessary, which usually involves replacing defective valves with artificial valves. Surgery is very safe and can be done on even babies.
The breath itself does not kill. It is not a disease that can kill, but a sign that something worse may be affecting the heart, such as valve stenosis or valve failure, or even more serious problems. The diseases that cause the murmur can lead to death depending on the stage and severity.
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