Heart sounds
Alternative names:
abnormal heart sounds; chest sounds - murmurs; heart murmurs; heart sounds - abnormal
Definition:
The noises produced by closure of the heart valves.
Considerations:
Heart sounds are commonly evaluated by listening with a stethoscope (auscultation). They can also be evaluated with an echocardiogram or other tests.
The normal heart has four chambers--two upper chambers (called atria) and two lower chambers (ventricles). The heart valves are membranous structures that temporarily close to permit blood flow in only one direction. They are located between the atria and ventricles, and between the ventricles and the major arteries from the heart (called the great vessels).
Normal heart sounds are called S1 and S2. They are the "lubb-dupp" sounds that are thought of as the heartbeat. These sounds are produced when the heart valves close. Because the heart is also divided into a "right side" and a "left side", sometimes these sounds may be somewhat divided--most commonly noted is a "split S2" caused when the right and left ventricles contract at very slightly different times. This is a normal finding in many people, but can occasionally indicate an abnormality such as enlargement of one of the ventricles.
Murmurs are blowing, whooshing, or rasping sounds. They are the result of vibrations caused by abnormal blood flow patterns. This can happen when a valve does not close tightly (such as with mitral regurgitation), when there is an irregularity in the shape of a heart chamber or one of the great vessels (such as an aortic aneurysm), or when the blood is flowing through a narrowed opening or a stiff valve (such as with aortic stenosis).
A murmur does not necessarily indicate a disease or disorder, and all heart disorders do not cause murmurs. Murmurs are classified,("graded") depending on their ability to be heard by the examiner. The grading is on a scale with grade I being barely detectable. An example of a murmur description is a grade II/VI murmur (grade 2 on a murmur scale of 1 to 6).
Also used to describe a murmur is the stage of the heartbeat when the murmur is heard. Whether the murmur occurs in the resting stage (diastole) or contracting stage (systole), whether it is early or late in the stage, or whether it occurs throughout the heartbeat, are important clues to the cause of the murmur. For example, a presystolic murmur is heard just BEFORE systole and is usually caused by narrowing of the mitral or tricuspid valve (the valves between the atria and the ventricles).
The location where the health care provider hears the murmur loudest is also often noted.
Common causes:
Murmurs: Other sounds: - Left ventricular hypertrophy (enlargement) may cause a split S2.
- Emotional stress can sometimes cause a temporary change in the heart sounds.
Note: There may be other causes of abnormal heart sounds. This list is not all inclusive, and the causes are not presented in order of likelihood. The causes of this symptom can include unlikely diseases and medications. Furthermore, the causes may vary based on age and gender of the affected person, as well as on the specific characteristics of the symptom such as location, quality, time course, aggravating factors, relieving factors, and associated complaints. Use the Symptom Analysis option to explore the possible explanations for abnormal heart sounds, occurring alone or in combination with other problems.
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