What causes the characteristic heart tones

Heart sounds - listening to the heart with a stethoscope

Introduction: the stethoscope

You probably know this from visits to your family doctor. It is easy to use and inexpensive, making it one of the most widely used devices in a doctor's office when it comes to examining the respiratory and cardiovascular system (i.e., the lungs and heart).

Listening to the heart

Listening to the heart (cardiac auscultation) is often the first examination to discover evidence of an underlying heart defect. The doctor can hear this by placing it on the front and back of the torso.

The sound of a healthy heart

Every heart produces characteristic rhythmic tones: every beat of a healthy heart consists of two tones, often described as “lab” (first tone) and “dab” (second tone). These sounds are created by the closing of the valves and the blood flowing through the heart.

Insignificant heart murmurs

Sometimes you can hear other sounds, called sounds, in addition to the normal heart sounds. However, detecting heart murmurs doesn't necessarily have to be a bad sign, as there are harmless heart murmurs that are insignificant (benign). These can e.g. B. be triggered by the position of the child during the examination or by his It is estimated that around 50% of all newborns and young children have heart murmurs, but most of them go away on their own over time.

Abnormal heart murmurs

However, a heart murmur can also be triggered by abnormal blood flow, which can be caused by a congenital heart malformation. For example, the flow of blood through a heart valve might be blocked (stenosis), or a valve might not close properly (insufficiency). This can create turbulence or cause the blood to flow in the wrong direction.

Even if a heart murmur occurs as a result of an underlying heart defect, other symptoms need not appear automatically. Even so, there are some symptoms that indicate a heart defect. These are e.g. B. chest pain, arrhythmia, breathlessness, exhaustion or, in severe cases,. Not every congenital heart defect results in abnormal sounds that can be heard with the. Surprisingly, it is often precisely the most complex heart defects in which there is no abnormal heart murmur at all.

Further examinations to confirm the diagnosis

Any patient who has a heart murmur needs further examinations to determine the meaning of the abnormal sounds. Certainly there are experienced doctors (e.g. pediatric cardiologists) who would be able to distinguish insignificant from pathological ones and who could even estimate the type and location of the heart defect. However, additional examinations are essential in order to make a reliable diagnosis and to get a more detailed overview of the heart and the surrounding organs. These additional exams will likely include the electrocardiogram () and echocardiography.

Checked by: Dr. Petra Böttler
Last update: 2008-09-23