Question

During your physical examination, what are you listening for at each different location of the heart exam? Discuss all locations making sure to also include the definition of point of maximal intensity.  Where would you listen for and how do you assess for most accurate heart rate?

Answer 1

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.

Primary heart sounds:

In healthy adults, there are two normal heart sounds, often described as a lub and a dub that occur in sequence with each heartbeat.

The first heart sound, or S1, forms the "lub" of "lub-dub" and is composed of components M1 (mitral valve closure) and T1 (tricuspid valve closure), which are atrioventricular valves.

The second heart sound, or S2, forms the "dub" of "lub-dub" and is composed of components A2 (aortic valve closure) and P2 (pulmonary valve closure), which are semilunar valves.

Extra heart sounds:

In addition to the above normal sounds, a variety of other sounds may be present including heart murmurs, adventitious sounds, and gallop rhythms S3 and S4.

Murmurs may be physiological (benign) or pathological (abnormal). Abnormal murmurs can be causes by stenosis restricting the opening of a heart valve, resulting in turbulence as blood flows through it. Different murmurs are audible in different parts of the cardiac cycle, depending on the cause of the murmur.

Surface anatomy:

The aortic area, pulmonic area, tricuspid area and mitral area are areas on the surface of the chest where the heart is auscultated.

Aortic valve (to aorta)	right second intercostal space	upper right sternal border
Pulmonary valve (to pulmonary trunk)	left second intercostal space	upper left sternal border
Erb's point	Left third intercostal space	left sternal border
Tricuspid valve (to right ventricle)	right fourth, fifth intercostal spaces	right sternal border
Mitral valve (to left ventricle)	left fifth intercostal space	left midclavicular line

Point of maximum intensity:

The point of maximum intensity is the position on the chest where the impulse of the left ventricle of the heart is felt most strongly. This is normally in the fifth intercostal space on, or just medial to, the left midclavicular line. It is abbreviated as PMI .

Recording heart sounds:

Using electronic stethoscopes, it is possible to record heart sounds via direct output to an external recording device, such as a laptop or MP3 recorder.

The most accurate readings will come from a lab test or other clinical method.