Heart Examination – Heart Sounds: A Comprehensive Guide

I. Heart Examination

1. Examination Technique:

• Positioning: The patient should lie supine or with a slight leftward tilt. The examiner stands on the patient’s right side.

• Observation:

• Respiration: Respiratory rate (fast, slow, regular, irregular), type of breathing (shallow, deep, labored)

• Thoracic Deformities: Kyphosis, scoliosis, bulging chest (due to chronic pulmonary heart disease)

• Previous Surgical Scars: Indicate a history of cardiac surgery

• Apex Beat: The point where the heart beats most strongly.

• Palpation:

• Apex Beat: The location of the strongest heartbeat is usually at the 5th intercostal space (ICS) at the mid-clavicular line (MCL) on the left.

• Easily noticeable in thin, malnourished individuals.

• An apex beat diameter greater than 2 cm compared to normal suggests left ventricular hypertrophy.

• A leftward displacement of the apex beat suggests right ventricular enlargement.

• Thrills: A palpable vibration that indicates the presence of a loud murmur (grade 4/6 or greater), with a rough quality and low to mid-frequency.

• Harzer’s Sign: Right ventricular dilatation, where the heartbeat is clearly felt in the left parasternal area and the epigastrium. Using 1-2 fingers, you can feel the right ventricle beating.

2. Auscultation:

• Auscultation Sites:

• Apex and Mitral Valve Area: 5th ICS at the MCL on the left (where the apex beat is strongest).

• Tricuspid Valve Area: 4-5th ICS at the left sternal border.

• Pulmonic Valve Area: 2nd ICS at the left sternal border.

• Aortic Valve Area: 2nd ICS at the right sternal border, 3rd ICS at the left sternal border.

• Information to be Recorded:

• Rhythm: Regular or irregular, completely irregular, or with a rhythm (extrasystole).

• Heart Rate: Number of beats per minute.

• S1, S2: Sounds produced by the closure of the atrioventricular valves (S1) and the aortic valves (S2).

• S3, S4: Abnormal sounds occurring in the middle of diastole (S3) and at the end of diastole (S4).

• Other Abnormal Heart Sounds: Murmurs, clicks, rubs…

3. Maneuvers:

• Postural Changes:

• Have the patient stand up and then squat down quickly.

• Blood from the lower extremities and abdomen is trapped, increasing the volume returning to the heart and temporarily increasing its size.

• This can cause murmurs to intensify in cases of mitral valve prolapse, hypertrophic cardiomyopathy; murmurs decrease in cases of mitral stenosis.

• Valsalva Maneuver:

• Instruct the patient to take a deep breath and then forcibly exhale with the glottis closed.

• This restricts venous return to the heart, decreasing left ventricular volume and reducing murmur intensity (mitral stenosis, hypertrophic cardiomyopathy).

• It can increase murmur intensity in mitral valve prolapse.

• Caution: Do not perform for more than 10 seconds as it can cause hypoventilation and hypotension.

• Deep Inspiration: Increased venous return to the heart causes the pulmonic valve to close later due to the right ventricle needing more time to expel the increased blood volume. This results in a physiologic splitting of S2.

• After Extrasystoles: Helps distinguish a murmur due to aortic stenosis from a murmur due to mitral regurgitation.

• Nitrates: Reduces peripheral vascular resistance, increasing blood flow to the heart, helping to identify the cause of murmurs.

II. Heart Sounds:

1. S1:

• Mechanism: Caused by the closure of the atrioventricular valves, marking the beginning of ventricular systole.

• Characteristics: A low-pitched, long sound, heard most prominently in the apex region. It has two components:

• Mitral valve closure: Heard clearly at the apex.

• Tricuspid valve closure: Heard clearly at the left sternal border.

• In complete right bundle branch block: The two components of S1 are widely separated.

• In complete left bundle branch block: The mitral valve closes late, causing the two components to merge into a single sound.

2. S2:

• Mechanism: Caused by the closure of the aortic valves, marking the beginning of ventricular diastole.

• Characteristics: Sharp and short, heard most prominently at the 2nd ICS at both sternal borders. It has two components:

• Aortic valve closure: Heard clearly at the 2nd ICS at the right sternal border.

• Pulmonic valve closure: Heard clearly at the 2nd ICS at the left sternal border.

• To hear S1 clearly:

• Place your finger on the apex, carotid artery: Your finger will tap with S1.

• Use the diaphragm of the stethoscope, placed over the apex.

• S1 splitting is widened when:

• Electrical activity of the heart: Right bundle branch block.

• Mechanical activity: Mitral stenosis.

• S1 intensity depends on four factors:

• Distance between the heart and chest.

• Valve leaflet position at the beginning of ventricular contraction.

• Leaflet flexibility.

• Ventricular contractility.

• With inspiration, S2 splits physiologically because: Increased intrathoracic volume causes more blood to return to the right ventricle, increasing its volume and delaying pulmonic valve closure.

• Differentiate S1 from: S4, systolic ejection click.

• In mitral stenosis due to rheumatic heart disease, S1 is very loud because: The left atrium is dilated, left atrial pressure is increased, and the mitral valve opens slowly but closes rapidly, producing a loud, sharp sound.

• S2 intensity depends on: Aortic and pulmonic pressures, valve leaflet movement.

• Increased pulmonic valve closure sound occurs in:

• Hypertension.

• Aortic stenosis.

• Aorta close to the chest wall (due to dilatation, hypertrophy).

• Increased pulmonic valve closure sound occurs in: Increased pulmonary pressure.

• Increased pulmonary pressure is often caused by: Left heart failure, mitral stenosis, primary pulmonary hypertension.

3. Wide S2 Splitting Occurs in:

• Delayed Pulmonic Valve Closure:

• During normal inspiration.

• Pulmonic stenosis.

• Right bundle branch block.

• Early Aortic Valve Closure:

• Aortic regurgitation.

• Ventricular septal defect.

4. Fixed S2 Splitting is found in: Atrial septal defect.

5. Paradoxical S2 Splitting Occurs:

• Delayed Aortic Valve Closure: Aortic stenosis increases the time the valve is open longer than closed.

• Left bundle branch block, creating a right ventricular pacemaker.

6. S3:

• Mechanism: Occurs during the middle of diastole, when ventricular filling is rapid.

• To hear S3 clearly: Use the bell of the stethoscope, increase venous return to the heart by having the patient squat or lie supine with their legs raised.

• Most prominent in: Children, adults under 40, athletes, pregnant women.

• When ventricular dilation is abnormal: Pathological S3 + rapid heart rate produces a “gallop” sound.

• Gallop sound is best heard:

• Left: Using the bell of the stethoscope at the apex.

• Right: Using the bell of the stethoscope at the tricuspid area just below the sternum.

• With deep inspiration: Right-sided gallop is heard clearly due to increased venous return, increasing right ventricular volume.

• With expiration: Thoracic diameter decreases, increasing left ventricular volume, making the left-sided gallop more audible.

• When ventricular dilation is abnormal: Pathological S3 + rapid heart rate produces a “gallop” sound.

• Gallop sound is best heard:

• Left: Using the bell of the stethoscope at the apex.

• Right: Using the bell of the stethoscope at the tricuspid area just below the sternum.

• With deep inspiration: Right-sided gallop is heard clearly due to increased venous return, increasing right ventricular volume.

• With expiration: Thoracic diameter decreases, increasing left ventricular volume, making the left-sided gallop more audible.

7. S4:

• Mechanism: The sound of blood being forced from the atrium into the left ventricle at the end of diastole, during the period of slow filling.

• Pathological S4 occurs in: Atrial hypertrophy, leading to ventricular dilatation at the end of diastole (hypertension, hypertrophic cardiomyopathy).

• S4 is most clearly heard: After exertion.

8. Systolic Ejection Click:

• Mechanism: The sound of aortic or pulmonic valve opening, immediately after S1. It’s caused by the vibration of the aortic or pulmonic valve leaflets as they open to their maximum extent and curve backward toward the lumen of the aorta or pulmonary artery.

• Characteristics: A sharp, high-frequency sound, best heard with the diaphragm of the stethoscope.

• In patients with mitral valve prolapse: Mid-late systolic clicks are caused by the prolapsing leaflet bowing into the left atrium, leading to sudden stretching of the valve leaflet and chordae tendineae.

9. Murmurs:

• Mechanism: Vibrations caused by turbulent blood flow from a wider area through a narrow space back to a wider area.

• Types of Murmurs:

• Ejection murmurs.

• Regurgitant murmurs.

• Continuous murmurs.

• Characteristics to Evaluate Murmurs:

• Location where best heard.

• Timing of occurrence.

• Intensity.

• Quality.

• Radiation.

• Change with maneuvers.

• Intensity:

• Murmur grading according to Levene-Harvey: 6 grades.

• Grade 1: Soft, only heard with careful listening in a quiet room.

• Grade 2: Audible when the stethoscope is placed on the chest, with a soft intensity.

• Grade 3: Clearly audible murmur without a thrill.

• Grade 4: Loud murmur with a thrill.

• Grade 5: Very loud murmur with a thrill; can be heard with half of the stethoscope off the chest.

• Grade 6: Very loud murmur with a thrill; can be heard with the stethoscope off the chest for several millimeters.

10. The mechanism of clicks: Due to valve leaflet vibration and bending backward – opposite to the original direction. They are clearly heard when pressure in the ventricles increases.

11. The mechanism of systolic murmurs:

• Obstruction of ventricular outflow: Hypertension, valve stenosis.

• Dilated aortic root, pulmonary artery.

• Increased blood flow through the valve.

• Atrioventricular valve regurgitation: Backflow murmur.

• Innocent murmurs.

12. Characteristics of early-mid systolic murmurs: Ejection murmurs, beginning after S1. Turbulent blood flow (whirlpool) through the stenotic valve, obstructed ventricular outflow. Increased obstruction level, longer murmur duration.

13. Characteristics of an aortic stenosis murmur: Heard clearly at the 2nd ICS on the right, radiating to the neck and right shoulder, as blood flows with high velocity. In case of a ventricular extrasystole, the extrasystolic murmur increases due to stenosis, and remains unchanged if it is a regurgitation.

14. Radiation of the pulmonic stenosis murmur: Toward the left shoulder.

15. Characteristics of a hypertrophic obstructive cardiomyopathy murmur:

• Blood flow through the narrowed ventricle.

• Heard clearly at the left sternal border in mid-systole, radiating to the carotid artery.

• Rough, harsh quality, intensifies when standing, decreases when squatting.

• Associated with S2 splitting.

16. Pan-systolic murmur: Begins simultaneously with S1 and occupies the entire systole. It’s a regurgitant murmur due to valve incompetence.

17. Murmur radiation depends on:

• Direction of backflow:

• Anterior and inward (posterior leaflet involvement): Radiates towards the left sternal border, cardiac base.

• Posterior, outward (anterior leaflet involvement): Radiates towards the left axilla, left shoulder.

18. Accompanying symptoms depending on the severity of mitral regurgitation:

• Mild: Systolic murmur.

• Moderate: Associated with gallop rhythm.

• Severe: S2 splitting.

19. Rivero-Carvalho sign in tricuspid regurgitation: Murmur increases with inspiration. Blood from the periphery returns easily to the heart, increasing the volume of each contraction and the velocity of the regurgitant flow.

20. Tricuspid regurgitation is often accompanied by:

• Prominent jugular veins.

• Large V waves.

• Hepatomegaly.

21. Characteristics of the systolic murmur due to ventricular septal defect:

• Rough, harsh quality.

• Heard clearly along the left sternal border.

• Accompanied by a thrill.

22. Differentiating a systolic murmur due to valve stenosis or regurgitation depends on:

• Location and radiation of the murmur.

• Murmur changes after extrasystoles.

23. Early diastolic murmur: The sound of blood regurgitating back into the ventricle due to aortic valve incompetence.

24. Mid-diastolic murmur – diastolic rumble in mitral stenosis:

• The sound of blood swirling forcefully through the narrowed opening from the atrium into the ventricle, causing vibration of the heart structures.

• Similar to a rumbling sound, irregular, rough, can be accompanied by a thrill when palpating the apex.

• Occurs after the opening click of the valve.

25. A faint diastolic rumble may be inaudible when: The mitral valve is heavily calcified, with limited leaflet movement.

26. The diastolic rumble in tricuspid stenosis differs from mitral stenosis:

• Intensity increases with inspiration.

• Heard clearly at the left sternal border, 4th-5th ICS.

• With inspiration, atrial volume increases, the atrioventricular pressure gradient increases.

27. Austin Flint murmur: Occurs at the end of diastole in moderate to severe aortic regurgitation. Due to rapid increase in left ventricular pressure from receiving blood from both the atrium and the aorta, causing valve closure to be rapid and in the opposite direction of blood filling the ventricle.

28. Continuous murmurs: A murmur that begins in mid-systole and continues continuously into part or all of diastole.

29. Causes of continuous murmurs:

• Patent ductus arteriosus.

• Arteriovenous fistulas.

• Abnormal blood flow in arteries or veins.

30. Cause of pathological S3: Due to abnormal ventricular dilation capacity.

Note:

• The above information is for general knowledge and reference purposes only. Accurate diagnosis requires evaluation by a cardiologist.

• Heart examinations should be conducted in a quiet environment with appropriate medical equipment.

• Pay attention to the patient’s medical history, family history, and clinical symptoms for accurate diagnosis.

We hope this comprehensive guide has helped you gain a better understanding of heart examinations and heart sounds. Stay healthy!