LECTURE 1 (Auscultation/Heart sounds)

Question 1

How does the heart function?

Answer 1

The heart is a muscular organ and has four chambers that receive and pump blood - right atrium, right ventricle, left atrium, left ventricle

Question 2

What causes heart sounds?

Answer 2

• Beating heart
• Resultant flow of blood through it
• Turbulence created when the heart valves snap shut

Question 3

Describe the different sections of the Stethoscope

Answer 3

• TUBE = transmits sounds from chest piece to ear pieces
• EARPIECES = should always face forward
• BELL = used for low frequency
• DIAPHRAGM = used for high frequency sounds
• CHEST PIECE = pressure determining function

Question 4

What is Systole and Diastole?

Answer 4

Systole = ventricles contract to pump out blood

Diastole = ventricles relax and fill with blood

Question 5

In a healthy adult, which two sounds can be heard?

Answer 5

‘lub’ and ‘dub’

[third and fourth sounds may be heard in some healthy people but can indicate impairment of the heart function]

Question 6

What is the difference between S1 & S2 and S3 & S4?

Answer 6

S1 & S2 = High pitched

S3 & S4 = Low pitched

Question 7

What is the importance of the First heart sound (S1)?

Answer 7

• Produced by closing of AV valves -> Best heard in Mitral and Tricuspid areas on Precordium
• High pitched -> Auscultated using the DIAPHRAGM of stethoscope
• Occurs just after QRS complex -> Marks beginning of systole
• Prolonged & dull in nature
• Frequency: 50-60 Htz Time: 0.15 secs

Question 8

Describe the Abnormal first heart sound?

Answer 8

• Loud S1 -> Mitral Stenosis
• Soft S1 -> Mitral Regurgitation
• Widened-Split S1 - Right bundle branch block (Delayed T1)

Question 9

What is the importance of the Second heart sound (S2)?

Answer 9

• Produced by the closing of SEMILUNAR VALVES -> Best heard in Aortic and Pulmonary areas on Precordium
• Occurs after T-wave -> Marks end of systole (beginning of diastole)
• High pitched -> Auscultated using the diaphragm of Stethoscope
• Short and sharp
• Frequency: 80-90 Htz Time: 0.11 sec

Question 10

Describe the Abnormal second heart sound

Answer 10

• Loud S2 -> Pulmonary hypertension
• Soft S2 -> Pulmonary Stenosis
• Physiological splitting of S2 -> Normal in inspiration (Young patients)
• Fixed splitting of S2 -> Atrial Septal Defect (ASD)

Question 11

What is the importance of the Third heart sound (S3)?

Answer 11

• Produced by rapid filling and expansion of ventricles -> Occurs just after S2 in diastole when AV valves open
• Normmal in young patients & pregnancy
• Often a sign of systolic heart failure
• Occurs during passive LV filling
• Requires a very compliant LV
• Frequency: 20-30 Htz Time: 0.1 sec

Question 12

What is the third heart sound (S3) also called?

Answer 12

Ventricular Gallop

Question 13

What is the importance of the Fourth heart sound (S4)?

Answer 13

• Produced by forceful atrial contractions forcing blood into stiff ventricles
• Occurs immediately before S1 in LATE DIASTOLE
• Low pitched -> Use bell of stethoscope
• Occurs during active LV filling
• Requires a Non-compliant LV
• Indicates atrial hypertrophy (Seen in AS) or stiff ventricles (seen in myocardial infarction -> causes fibrous tissue formation)

Question 14

Unlike S3, S4 is always ____________

Answer 14

Pathological

Question 15

Can both S3 and S4 be a sign of systolic congestive Heart Failure?

Answer 15

YES

Question 16

What are other extra heart sounds?

Answer 16

• Systolic ejection click
• Mitral valve prolapse click
• Opening snap
• Tumor plop
• Pericardial knock

Question 17

Systolic ejection click

Answer 17

• Indicates a bicuspid aortic valve -> leaflets dome suddenly prior to opening creating the sound
• Heard just after the S1 heart sound

Question 18

Mitral valve prolapse click

Answer 18

• Mid systolic click followed by a uniform, high pitched murmur
• Heard best at cardiac apex
• Sudden standing -> Preload decreased -> Click moves earlier in systole
• Sudden squatting -> Preload increases -> Click moves later in systole

Question 19

Opening snap

Answer 19

• Increased left atrial opening pressures cause an opening snap to occur when the mitral valve leaflets suddenly tense and dome into LV in early diastole
• Best heard at apex

Question 20

Tumour plop

Answer 20

• Early diastolic low-pitched sound just after S2
• May be followed by a low-pitched diastolic murmur

Question 21

Pericardial knock

Answer 21

• Occurs earlier than a S3 heart sound
• Can be present in patients with Constrictive pericarditis (early filling of LV is limited from the constrictive process)

Question 22

What are the six different characteristics to be assessed during auscultation?

Answer 22

• Location
• Intensity
• Duration
• Pitch
• Quality
• Timing

Question 23

Which positions can patients be examined in?

Answer 23

• Lying supine
• Left lateral decubitus position
• Sitting
• Leaning forward

Question 24

Where are the points for heart auscultation?

Answer 24

APTM

• AORTIC = 2nd Intercostal space to the right sternal border
• PULMONIC = 2nd Intercostal space to the left sternal border
• TRICUSPID = 5th Intercostal space to the lower left sternal border
• MITRAL = Apex, Point of maximum impulse & 5th Intercostal space at Midclavicular line

Question 25

Where is Erb’s point?

Answer 25

3rd Intercostal space to the left sternal border