Auscultation

Auscultation schedule:
Introduction

Auscultation is the art of listening to the body sounds with the aid of a stethoscope or a machine device. There are normal heart sounds and abnormal ones and there are also normal breath sounds which are said to be vesicular and abnormal ones emanating from the lungs.

To listen to breath sounds (check lung physiology and chemical pathology) follow the same points of percussion in auscultation. To listen to heart sounds try to follow the areas where the valves of the heart can be best heard. Also note the surface anatomy of heart valves.

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1 mitral area 3 pulmonary area 4 aortic area 5 tricuspid area

Introduction to Auscultation

Right lateral

Posterior

Left lateral

Workpage

Normal heart sound consist of two sounds. -First heart sound and second heart sound. Both are best heard in the apex. The apex of the heart is usually at the left 5th intercostal space just medial to the midclavicular line.

Physiology of heart sounds
First heart sound is caused by the closure of the tricuspid and mitral valves and normally lasts for 0.15 seconds with a frequency of about 25-45Hz. The second sound is shorter and lasts for 0.12 seconds with a frequency of about 50Hz. It is caused by closure of aortic and pulmonary valves at the end of ventricular systole. It may be split physiologically between the aortic and pulmonary valves. The events in the cardiac cycle show the first sound occurs at systole while the second comes at diastole.

Note: Position adopted during clinical examination is by the right hand side of the patient. This picture is only for illustration.