|
Tips for Cardiac Auscultation |
E-mail
|
Cardiac auscultation is one of the most important steps in the examination of cardiovascular system. This article is a list of some important tips on cardiac auscultation.
1 - The First Heart Sound corresponds to the carotid pulse. Its identification is the first important step of cardiac auscultation.
2 - The Second Heart Sound must be analyzed with the diaphragm of the stethoscope at the pulmonary area where the two components of this sound are best identified. Points to note are its variations with different phases of respiration and splitting.
3 - The Third Heart Sound is usually best heard at the cardiac apex, in the left lateral position with the bell of the stethoscope.
4 - The Fourth Heart Sound is also best heard with the bell of the stethoscope at the cardiac apex (left heart origin S4) or tricuspid area (right heart origin S4).
5 - During Systole we can hear systolic ejection sounds (aortic or pulmonary stenosis), nonejection mid- to late- systolic clicks (prolapse, extracardiac) and also pansystolic (mitral or tricuspid regurgitations or VSD-ventricular septal defect) murmurs.
6 - In Diastole we may hear opening snaps (mitral or tricuspid stenosis), early diastolic murmurs (aortic regurgitation), mid diastolic murmurs (mitral or tricuspid stenosis).
7 - Frequently, but not always,the double and triple murmurs are due to combined valvular lesions. The pericardial friction rub is usually triple-phased, with a characteristic scratching quality.
8 - Continuous murmurs begin in systole and continue into the diastole, without interruption through the timing of second heart sound. They are due to arteriovenous shunts (classically described in PDA - patent ductus arteriosus) and venous hum.
9 - The major areas of auscultation (mitral at the apex, tricuspid, pulmonary and aortic areas) indicate zones where the cardiac sounds and murmurs are best heard, but do not ignore to auscultate all around the thorax. Especially remember to auscultate over the carotid arteries in the neck.
10- More information is obtained by studying the appearance or change of sounds and murmurs by appropriate postural, respiratory and functional changes (Valsalva, exercise, handgrip, amyl nitrite inhalation, etc). This is called dynamic auscultation.
Details on examination of the apex.
 |
