Hjertelyder

Hjertelyder, or heart sounds, are the noises produced by the movement of the heart and the closing of its valves during the cardiac cycle. The two main audible components are S1 and S2. S1, often described as a "lub," marks the closure of the atrioventricular valves at the start of ventricular systole. S2, the "dub," accompanies the closure of the semilunar valves at the end of systole and the beginning of diastole. In Norwegian medical usage, Hjertelyder refers to these sounds and their acoustic characteristics as indicators of valve function and blood flow.

S3 and S4 are additional heart sounds that may be heard under certain conditions. S3 occurs in early diastole and is associated with rapid ventricular filling; it can be normal in children and young adults but may indicate volume overload or heart failure in older patients. S4 occurs late in diastole just before S1 and is linked to decreased ventricular compliance, such as in hypertrophy or longstanding hypertension. Both are not always present and may require clinical correlation.

Murmurs and other adventitious sounds arise from turbulent blood flow across valves or through abnormalities in the heart or great vessels. Murmurs are typically described as systolic or diastolic and are graded by loudness. Their interpretation is guided by patient history and often supported by imaging, since murmurs can be benign or indicative of valve disease, congenital defects, or other cardiac conditions. Pericardial rubs and occasional clicks are other examples of abnormal sounds.

Auscultation is performed with a stethoscope placed at standard listening areas over the chest, with the patient in various positions to optimize detection. The diaphragm and bell may be used to detect different frequency components. The assessment of Hjertelyder is a fundamental part of the cardiovascular examination and is complemented by imaging modalities such as echocardiography for structural and functional evaluation.