Precordium is generally divided into four auscultatory areas, but other areas may be checked in specific situations. The common auscultatory areas correspond to the locations at which the corresponding valvular events are better heard.
- Aortic area: Also called primary aortic area as there is a secondary aortic area along the left sternal edge. Primary aortic area is the 2nd right intercostal space, close to sternum.
- Pulmonary area: 2nd left intercostal space, close to sternum.
- Tricuspid area: Lower left sternal edge, medial to apex beat.
- Mitral area: At the apex beat, usually within the mid clavicular line in the 5th left intercostal space.
Other auscultatory areas can be used in specific situations, though not in routine clinical examination of all cases:
- Erbs’s area: Third left intercostal space, close to sternum, where the murmur of aortic regurgitation may be better heard. This region is also called secondary aortic area.
- Roger’s area: Fourth left intercostal space, close to sternum where the murmur of small ventricular septal defect (maladie de Roger) is heard.
In addition to these certain regions are auscultation when specific lesions are suspected:
- Infraclavicular region (1st left intercostal space): The murmur of patent ductus arteriosus may be best heard here.
- Interscapular, scapular and infrascapular regions: Collateral murmurs and the bruit of coarctation of aorta may be checked for in these regions.
- Carotids: Murmur of aortic stenosis radiates to the carotids. Selective radiation to right carotid indicates supravalvular aortic stenosis. Carotid bruit can occur in carotid stenosis due to atherosclerosis and predisposes to stroke. Bruit is the vascular counterpart of murmur.
- Axilla: Murmur of mitral regurgitation radiates to the axilla and back. This is usually a feature seen in rheumatic mitral regurgitation with predominant involvement of anterior mitral leaflet. In papillary muscle dysfunction usually the posterior leaflet is involved and the mitral regurgitation murmur radiates medially and to the base of the heart rather than to the axilla.