During a checkup, your doctor will use a stethoscope to listen to your heartbeat to determine whether your heart is beating properly and has a normal rhythm. This gives your doctor information concerning the health of your heart. Show A heart murmur is an unusual sound heard between heartbeats. If your doctor hears a “murmur” or any other abnormal sounds coming from your heart, it may be an early indicator of a serious heart condition. A normal heartbeat has two sounds, a lub (sometimes called S1) and a dub (S2). These sounds are caused by the closing of valves inside your heart. If there are problems in your heart, there may be additional or abnormal sounds. Heart murmursThe most common abnormal heart sound is a heart murmur. A murmur is a blowing, whooshing, or rasping sound that occurs during your heartbeat. There are two kinds of heart murmurs:
An innocent murmur can be found in children and adults. It’s caused by the sound of blood moving normally through the heart. In adults, innocent heart murmur may be caused by physical activity, fever, or pregnancy. An abnormal murmur in a child is due to congenital heart malformations, which means they’re present at birth. It may need to be corrected with surgery. An abnormal murmur in adults is usually caused by problems with the valves that separate the chambers of your heart. If a valve doesn’t close tightly and some blood leaks backward, this is called regurgitation. If a valve has become too narrow or becomes stiff, this is known as stenosis. It can also cause a murmur. Murmurs are graded depending on how loud the sound is. The scale for grading runs from 1 to 6, where one is very faint and six is very loud — so loud that it may not need a stethoscope to be heard. Murmurs are also categorized as occurring during either the first sound (S1), as systole murmurs, or during the second sound (S2), as diastole murmurs. Galloping rhythmsOther heart sounds include a “galloping” rhythm, which involves additional heart sounds, S3 and S4:
You can also have both an S3 and an S4 sound. This is called a “summation gallop,” which can occur when your heart is beating very fast. A summation gallop is very rare. Other soundsClicks or short, high-pitched sounds may also be heard during your regular heartbeat. This could indicate a mitral valve prolapse, when one or both flaps of your mitral valve are too long. This can cause some regurgitation of blood into your left atrium. Rubbing sounds may be heard in people with certain kinds of infections. A rubbing sound is usually caused by an infection in your pericardium (a sac that surrounds your heart) due to a virus, bacteria, or fungus. Your heart is made up of four chambers. The two upper chambers are called the atria, and the two lower chambers are called the ventricles. Valves are located between these chambers. They make sure that your blood always flows in one direction.
Your pericardial sac surrounds your heart and protects it. Problems with these parts of your heart may lead to unusual sounds that your doctor can detect by listening to your heart with a stethoscope or by performing an echocardiogram test. Congenital malformationsMurmurs, especially in children, may be caused by congenital heart malformations. These can be benign and never cause symptoms, or they can be severe malformations that require surgery or even a heart transplant. Innocent murmurs include:
One of the more serious congenital problems that causes heart murmurs is called Tetralogy of Fallot. This is a set of four defects in the heart that lead to episodes of cyanosis. Cyanosis happens when an infant or child’s skin turns blue from lack of oxygen during activity, such as crying or feeding. Another heart problem that causes a murmur is patent ductus arteriosus, in which a connection between the aorta and the pulmonary artery fails to close correctly after birth. Other congenital problems include:
Heart valve defectsIn adults, murmurs are usually the result of problems with heart valves. This may be caused by an infection, such as infective endocarditis. Valve problems can also simply occur as part of the aging process, due to wear and tear on your heart. Regurgitation, or backflow, happens when your valves don’t close properly:
Stenosis is a narrowing or stiffening of your heart valves. Your heart has four valves and each valve can have stenosis in a unique way: Another cause of heart murmurs is stenosis caused by hypertrophic cardiomyopathy. In this condition, the muscle of your heart thickens, which makes it harder to pump blood through your heart. This results in a heart murmur. This is a very serious disease that’s often passed on through families. Causes of clicksHeart clicks are caused by problems with your mitral valve. Mitral valve prolapse is the most common cause. It occurs when one or both flaps of your mitral valve are too long. This can cause some regurgitation of blood into your left atrium. Causes of rubsHeart rubs are caused by friction between layers of your pericardium, a sac around your heart. This is usually caused by an infection in your pericardium due to a virus, bacteria, or fungus. Causes of galloping rhythmsA galloping rhythm in your heart, with a third or fourth heart sound, is very rare. An S3 sound is likely caused by an increased amount of blood within your ventricle. This may be harmless, but it can also indicate underlying heart problems, such as congestive heart failure. An S4 sound is caused by blood being forced into a stiff left ventricle. This is a sign of serious heart disease. Your doctor will listen to your heart with a stethoscope, a medical device used to listen to your heart, lungs, and other organs in your body. If they detect problems, your doctor may order an echocardiogram. This is a test that uses sound waves to create a moving picture of your heart to help your doctor get a better understanding of the abnormalities detected. If your doctor hears any abnormal heart sounds, they may ask you questions about your family. If any of your family members have also had abnormal heart sounds or a history of heart problems, it’s important to tell your doctor. It may make diagnosing the cause of your abnormal heart sounds easier. You doctor will also ask if you’ve had any other symptoms of heart problems, such as:
Your doctor may also listen to your lungs and may examine you to see if you have signs of liver enlargement. These symptoms may provide clues about what type of heart problem you’re experiencing. Abnormal heart sounds often indicate some type of underlying heart disease. This may be treated with medication, or it may require surgery. It’s important to follow up with a heart specialist to learn the details of your condition.
The cardiac cycle represents the hemodynamic and electric changes that occur in systole and diastole. It has many phases. Phases of the Cardiac Cycle
Heart SoundsNormal pressures in various chambers of the heart The first heart sound (S1) represents closure of the atrioventricular (mitral and tricuspid) valves as the ventricular pressures exceed atrial pressures at the beginning of systole (point a). S1 is normally a single sound because mitral and tricuspid valve closure occurs almost simultaneously. Clinically, S1 corresponds to the pulse. The second heart sound (S2) represents closure of the semilunar (aortic and pulmonary) valves (point d). S2 is normally split because the aortic valve (A2) closes before the pulmonary valve (P2). The closing pressure (the diastolic arterial pressure) on the left is 80 mmHg as compared to only 10 mmHg on the right. This higher closing pressure leads to earlier closure of the aortic valve. In addition, the more muscular and stiff "less compliant" left ventricle (LV) empties earlier than the right ventricle. The venous return to the right ventricle (RV) increases during inspiration due to negative intrathoracic pressure and P2 is even more delayed, so it is normal for the split of the second heart sound to widen during inspiration and to narrow during expiration. Clinically, this is more remarkable with slow heart rates. The third heart sound (S3) represents a transition from rapid to slow ventricular filling in early diastole. S3 may be heard in normal children. The fourth heart sound (S4) is an abnormal late diastolic sound caused by forcible atrial contraction in the presence of decreased ventricular compliance.
Abnormally wide splitting of S2 may occur in: a) RV volume overload, such as atrial septal defect (ASD) and anomalous pulmonary venous connection. In these cases, the split is usually wide and "fixed" with no difference between inspiration and expiration due to fixed RV volume (see ASD section) b) RV outflow obstruction, such as pulmonary stenosis (PS) c) Delayed RV depolarization such as complete right bundle branch block Narrow splitting of S2 occurs in: a) Pulmonary hypertension as the pulmonary valve closes earlier due to high pulmonary resistance b) Mild to moderate aortic stenosis as the A2 is delayed Single S2 may occur: a) If one of the semilunar valves is missing, as in pulmonary or aortic valve atresia and truncus arteriosus b) If both valves close simultaneously as in pulmonary hypertension with equal pulmonary and aortic arterial pressures c) If both valves close simultaneously as in double outlet single ventricle or in large VSD with equal ventricular pressures d) Posterior displacement of the pulmonary valve away from the chest wall as in d-TGA Paradoxical splitting of S2 (P2 is heard before A2) occurs in: a) Severe aortic stenosis b) Left bundle branch block In both conditions, the aortic valve (A2) closes after the pulmonary valve (P2). Since the respiration only affects P2, its effect in paradoxical splitting is the opposite of normal, i.e. inspiration causes narrow splitting while expiration causes wide splitting of S2. Heart MurmursMurmurs are additional sounds generated by turbulent blood flow in the heart and blood vessels. Murmurs may be systolic, diastolic or continuous. Grading of systolic mumers based on thier intensity
Systolic murmurs are the most common types of murmurs in children and based on their timing within systole, they are classified into: a) Systolic ejection murmurs (SEM, crescendo-decrescendo) result from turbulent blood flow due to obstruction (actual or relative) across the semilunar valves, outflow tracts or arteries. The murmur is heard shortly after S1 (pulse). The intensity of the murmur increases as more blood flows across an obstruction and then decreases (crescendo-decrescendo or diamond shaped). Innocent murmurs are the most common cause of SEM (see below). Other causes include stenotic lesions (aortic and pulmonary stenosis, coarctation of the aorta, Tetralogy of Fallot (TOF)) or relative pulmonary stenosis due to increased flow from an ASD
Crescendo decrescendo murmur b) Holosystolic (regurgitant) murmurs start at the beginning of S1 (pulse) and continue to S2. Examples: ventricular septal defect (VSD), mitral and tricuspid valve regurgitation.
Holosystolic murmur c) Decrescendo systolic murmur is a subtype of holosystolic murmur that may be heard in patients with small VSDs. In the latter part of systole, the small VSD may close or become so small to not allow discernible flow through and the murmur is no longer audible.
Decrescendo murmur Diastolic murmurs are usually abnormal, and may be early, mid or late diastolic.
Continuous murmurs are heard during both systole and diastole. They occur when there is a constant shunt between a high and low pressure blood vessel. Examples: patent ductus arteriosus (PDA) and systemic arterio-venous fistulas. This may also occur in surgically placed shunts such as a Blalock-Tauussig (BT) shunt between the aorta and the pulmonary artery. Innocent murmurs are common in children and have the following characteristics:
Summary of Heart Murmurs
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