page_title: Heart sounds
section_title: Primary heart sounds
hierarchical_section_title: Heart sounds / Primary heart sounds
context_page_description: Heart sounds are the noises generated by the beating heart and the resultant flow of blood through it. Specifically, the sounds reflect the turbulence created when the heart valves snap shut. In cardiac auscultation, an examiner may use a stethoscope to listen for these unique and distinct sounds that provide important auditory data regarding the condition of the heart.
  In healthy adults, there are two normal heart sounds, often described as a lub and a dub that occur in sequence with each heartbeat. These are the first heart sound and second heart sound,
  produced by the closing of the atrioventricular valves and semilunar valves, respectively. In addition to these normal sounds, a variety of other sounds may be present including heart murmurs, adventitious sounds, and gallop rhythms S₃ and S₄.
  Heart murmurs are generated by turbulent flow of blood and a murmur to be heard as turbulent flow must require pressure difference of at least 30 mm of hg between the chambers and the pressure dominant chamber will out flow the blood to non dominant chamber in diseased condition which leads to Left-to-right shunt or Right-to-left shunt based on the pressure dominance.
context_section_description: Normal heart sounds are associated with heart valves closing:
caption: Diagram showing relations of opened heart to front of thoracic wall. Ant. Anterior segment of tricuspid valve. A O. Aorta. A.P. Anterior papillary muscle. In. Innominate artery. L.C.C. Left common carotid artery. L.S. Left subclavian artery. L.V. Left ventricle. P.A. Pulmonary artery. R.A. Right atrium. R.V. Right ventricle. V.S. Ventricular septum.
exif: {}