Cardiac Auscultation

Of all the skills of the diagnostician the auscultation of the heart is particular difficult to learn. I hope that this page make it more easy to carry out.

The stethoscope

The bell, Is better for Low-pitched sounds, while the high-pitched sounds are best heard with the diaphragm.

The technique

• Approach the patient from the right side.
• When using the bell, one must take care to exert very little pressure.
• Excessive pressure converts the underlying skin into a diaphragm and eliminates very low-pitched sounds.
• One must concentrate solely on each phase of the cardiac cycle and each of the sounds separately.

On auscultation one should first try to discriminate :

• The heart sounds S1, S2 ,S3, S4
• Systolic sounds
• Diastolic sounds
• Continued sounds

At first listen to the S1 at every location. Then listen to the S2. After they are recognised, listen to the sounds witch are around the S1 and S2.

The 1st heart sound (S1)

It represents the closure of mitral and tricuspid valves. It is best heard in mitral and tricuspid areas.

• Normal: Splitting in inspiration may be heart, it has a high pitch.
• Loud: Mitral stenosis, tachycardia.
• Soft: Mitral regurgitation.

Normal, Splitted S1, Wide splitted S1.

The 2nd heart sound (S2)

Represents the closure of the aortic and pulmonary valves. It is best heard in the aorta and pulmonary areas.

• Normal : First aorta closure then pulmonary closure. Delayed pulmonary closure in inspiration. (increased right ventricular volume while decreased left ).
• Abnormally wide splitting: Late aorta closure in left bundle branch block and aorta stenosis.
• Early pulmonary closure in pre-excitation phenomena.
• Late pulmonary closure in increased volume flow through the right ventricle, such as atrial septum defect which is not varying with respiration.
• Reverse splitting (splitting increasing on expiration ) : Left bundle branch block , systemic hypertension, aorta stenosis.
• Loud : Aorta closure, because of the systemic hypertension and in pulmonary closure ( pulmonary hypertension ).
• Soft : Aorta closure, because of the aorta stenosis and pulmonary closure ( pulmonary stenosis ).

Splitted S2, Wide splitted 2S, Reversed splitting.

The 3rd heart sound (S3)

Occurs shortly after S2. It is early diastolic and occurs during passive diastolic filling. It Is low pitched, has a long duration and is best heard with the bell in the mitral and tricuspid areas.

• S3 (Right ventricular) increase with inspiration.
• S3 (Left ventricular) increase with expiration.
• Normal : young people < 35 years.
• Abnormal : Left and right heart failure, mitral regurgitation, constrictive pericarditis ( high pitched = is the pericardial knock ).

S3.

The 4th sound (S4)

Occurs just before S1. It is produced by the augmented diastolic ventricular filling near the end of the diastole and is caused by atrium contraction. It is loud due to a stiff ventricle. It is a low-pitched sound and best heard with the bell of the stethoscope. The ventricle can made stiff by : aortic stenosis, acute ischemia, hypertensive heart disease and myocard infarct.

• S4 (Right ventricular) increased with inspiration.
• S4 (Left ventricular ) decreased with inspiration.
• Its is always abnormal.
• It indicates a lesser degree of ventricular dysfunction than S3.

S4.

Summation gallop

Occurs when both S3 and S4 are present in a patient with tachycardia. Diastole may be shortened and the two sounds may be merged.

Summation gallop.

Ejection,systolic click

Heard in early systole and it represent, aorta stenosis or systemic hypertension.

Ejection systolic click.

Mid systolic click

Occur in mitral prolapse.

Mid systolic click.

Diastolic sounds

Opening snap.

Precedes the mid diastolic murmur of mitral stenosis when not calcified. Rare is tricuspid stenosis. Often heard at the apex or at the left sternal border. It is best heard with the diaphragm of the stethoscope.

• Loud: Elastic valve leaflets.
• Soft: Sclerosis, calcification of the valve, fibrosis.

opening snap.

Murmurs

Murmurs may be systolic, diastolic, or continuous. High-pitched are best heard with the diaphragm, low-pitched with the bell of the stethoscope.

• Timing (systolic diastolic ).
• Intensity grade (see below ).
• Quality (crescendo- decrescendo).
• Location.
• Pitch.
• Changes by respiration, or position.
• Radiation.

Grade

Murmurs are graded according to their intensity.

• Grade 1: barely audible with the utmost concentration.
• Grade 2: soft, but easily heard.
• Grade 3: loud without a thrill.
• Grade 4: loud with a thrill.
• Grade 5: loud with barely any contact between stethoscope and chest.
• Grade 6: loud, heard with the stethoscope off the chest.

Regurgitant murmurs:

Occur when a valve is meant to be closed, and it is not.

Stenotic murmur:

Occur when a valve meant to be fully open, and it is not.

Systolic murmurs

ejection murmur

this originate from the turbulent flow through narrowed or irregular valves or outflow tracts. It has a crescendo- decrescendo, diamond-shaped character.

• Normal: In children and infants, a soft systolic murmurs may occur without significance.
• It is also common in a high output state (pregnancy and tachycardia) .

• Aortic stenosis: Is best heard in the 2nd intercostal space at the right of the sternum. It radiates to the neck.
• Pulmonic stenosis: Is best heard to the left of the sternum in the 2nd intercostal space en does not radiate widely.
• Hypertrophic obstructive cardiomyopathy: Best heard at the lower left sternal border. It increases with Valsalva strain (raised thoracic pressure which impedes venous return ) and standing. It does not radiate to the neck.
• Mitral valve insufficiency: With the patient leis on the left lateral decubitus position. Best heard at the apex of the heart. It radiates toward the left axilla and varies with intensity.
• Tricuspid regurgitation: Best heard at the lower left sternal edge over the xiphoid. It increases with ventricular filling (inspiration ). It is a softer murmur than mitral regurgitation.

Aotra stenosis, Mitral insufficiency.

holosystolic murmur

A holosystolic murmur is do to regurgitation or shunts into chambers that throughout systole are at lower resistance.

• Ventricular septal defect: Heard at the left sternal edge in the 4th intercostal space. Louder with a increasing gradient over the ventricul. Softer when decreasing the gradient such as with pulmonary hypertension.

Holosystolic.

Diastolic murmurs

Early diastolic murmurs :

Listen in the early diastole, for the absence of silence.

• Aorta regurgitation: Blowing, high-pitched decrescendo sound. Heard along the left sternal edge and toward the apex.
• Pulmonic regurgitation: High-pitched decrescendo. Heard at the second left intercostal space at the sternal edge. It radiates toward the mid-right sternal edge.
• Graham steel murmur: This is when pulmonary regurgitation is secondary to pulmonary hypertension, which is itself due to mitral stenosis.

Aorta regurgitation.

Mid diastolic murmurs

• Mitral stenosis :Low-pitched apical diastolic murmur.Best heard after mild exercise. The patient is in left lateral decubitus position. The sound is best heard at the apex .
• Austin Flint murmur: Is due to fluttering of the anterior mitral valve cusp, caused by the regurgitant stream from aorta regurgitation.
• Carey Coombs murmur: Is due to thickening of the mitral valve leaflets witch is caused by rheumatic fever.
• Tricuspid stenosis : Heard in 4th and 5th intercostal space at the left sternum. It increase with: inspiration, sitting forward and exercise.

Mitral stenosis.

Continuous murmurs

Continuous murmurs indicate a constant shunt flow throughout systole and diastole and may be due to patent ductus arteriosus. It is loudest at the 2nd intercostal space just below the medial end of the left clavicle.

• Coarctation of the aorta or pulmonary artery.
• Aorticopulmonary window murmurs : Are central and at the 3rd intercostal space level.
• Branch stenosis of the pulmonary artery : Heard more diffused through the chest.
• Systemic or pulmonic A-V fistulas: Heard also more diffused through the chest.
• Congenital malformation.
• Coronary-cameral fistulas.
• Aorto-right ventricular or aorto-right atrial fistulas: The communications are best heard directly over the lesions

Dutus arteriosis.

Pericardial Friction Rub

The sound has the character of pieces of leather squeaking as they are rubbed together. Is a superficial, high-pitched, or scratchy sound that may be systolic, diastolic or triphasic. The rubs are best heard with the patient leaning forward or upon hands and knees with breath held in expiration.

Pericardial rub.

Author: Jos-Paul Scholten

Last Revision: 01 Sept 1998
Coments e-mail:
medicine@xs4all.nl