Chronological localisation during cardiac auscultation

Chronological Localization During Heart Auscultation

Yaroslav Shpak, M.D., cardiacauscultation.com

You may not know something or just scratch a surface of available information

Nevertheless, you still might be able to solve your problem effectively. This is acceptable…

But there are some key skills in every field, without which…

NOTHING AT ALL can be done.

This topic is exactly that case

What are we talking about?

In the sound stream we perceive during heart auscultation, we have to:

• separate each element

• locate each element in coordinates of the cardiac cycle

All “heart music” consists of two elements:

• Heart sounds. Short, beat-like or click-like.

• Heart murmurs. Prolonged in time.

The difference is in a continuance:

moment/d u r a t i o n

While listening to an abstract and disorganized sound of the heart…

it is necessary to split it into its constituent basic elements and precisely place each element in

relation to the phases of cardiac cycle.

Cardiac cycle repeats over time. Let’s depict time on a horizontal line. Time

goes from left to right. Like this:

There are two phases in cardiac cycle:

• Systole

• Diastole

During systole, ventricles eject blood.

During diastole, ventricles are filled with blood.

How to distinguish between systole and diastole?

There are two principal marks which

clearly distinguish systole and diastole.

They are the first heart sound (S1) and the second heart sound (S2)

S1 is formed by closing of the atrioventricular valves (mitral and tricuspide)

S2 is formed by closing of the semilunar valves (aortic and pulmonic)

No matter who is examined, S1 and S2 are

heard almost always

The period between T1 and T2 is systole

The period between S2 and S1 is diastole

It remains only to distinguish between T1 and T2

These four rules will help you:

• S1 and S2 sound differently

• S1 and S2 have specific areas, where they are extra loud

• S1-S2 period is usually shorter than S2-S1 period

• The peak of the carotid pulse wave falls on S1-S2 period

S1 and S2 sound differently

S1:

• Lower pitch, contains less high-frequency oscillations

• Lasts longer

S2:

• Clearer, clicking, contains more high-frequency oscillations

• Shorter in duration

S1 and S2 have specific areas, where they are extra loud

S2 is almost always louder at the base of the heart

Having caught S2 at the heart base and fixed our

attention on it, we can slowly move a chest piece of

our stethoscope toward the tricuspid and mitral areas. By fixing our attention on S2, we can correlate S2 in

relation to other auscultatory symptoms.

S1 is often louder at the apex of the heart. But not always.

S1-S2 period is usually shorter than S2-S1 period

This rule doesn’t work with tachycardia

The peak of carotid pulse wave falls on S1-S2 period

If, while auscultating, we start palpating pulse on the common carotid arteries, we will find out that...

The peak of common carotid pulse wave falls on S1-S2 period

Let’s repeat these four rules:

• S1 and S2 sound differently

• S1 and S2 have specific areas, where they are extra loud

• S1-S2 period is usually shorter than S2-S1 period

• The peak of the carotid pulse wave falls on S1-S2 period

After we separated all elements of the heart sound,

… we should define each element’s position within the cardiac cycle.

However, it is not enough to say that something registers in systole or diastole.

It is necessary to determine the exact position

Usually, it is enough to point out if auscultatory symptom registers at the beginning, middle or the end of systole or diastole.

For instance, this sound is early systolic:

And this murmur is late diastolic:

If the murmur continues throughout the entire systole, it is called pansystolic.

That’s all. Quite simple, isn’t it?