Heart sound 3

First heart sound (S1)

Closure of mitral and tricuspid valves at the end of atrial systole

Determinant of S1 intensity is equivalent to

Speed of valve closure

Relation of pulse rate to S1

Pulse rate is inversely proportional to heart rate

Loud S1 definition

Increased intensity of first heart sound

Mechanism of loud S1

Faster valve closure due to increased transvalvular gradient

3 main causes of Loud S1 sound

• tachycardia conditions

• Physiological

• Mitral stenosis / tricuspid stenosis

Causes of loud S1 – Tachycardia conditions

• Short PR interval

• Congestive heart failure (viral myocarditis)

• Thyrotoxicosis

• Pheochromocytoma

• Severe anemia

Physiological causes of loud S1

• Pregnancy

• Child

Loud S1 in mitral/tricuspid stenosis

• Increased transvalvular gradient

• Increased left atrial pressure → Faster opening of mitral valve → Faster elastic recoil → loud S1

In Calcified mitral stenosis, S1 is

Soft S1 ( due to calcification, elastic recoil is reduced )

Mitral stenosis effect on S1

Delayed closure of mitral valve due to increased transit time

Narrow split S1 consequence

Narrow split S1 →Single S1 → Reverse split S1

Soft S1 definition

Reduced intensity of first heart sound

Normal PR interval

120-200 msec

Causes of soft S1 due to Bradycardia

• Prolonged PR interval ( 1st degree heart block )

• Hypothyroidism

• SA node malfunction (sick sinus ysndrome)

• AV node malfunction (complete heart block)

• Bundle of his malfunction ( mobitz type 2)

Prolonged PR interval causes soft S1

First degree heart block

Endocrine cause of soft S1

Hypothyroidism

SA node malfunction

Sick sinus syndrome

AV node malfunction

Complete heart block

Bundle of His malfunction

Mobitz type II heart block

Other cause of soft S1

• Obesity ( cushing/metabolic syndrome ) - fat decrease intensity of sound

• Emphysema ( air in lung decrease intensity of sound )

• Mitral / tricuspid regurgitation

• Severe calcified mitral or tricuspid stenosis

S3 heart sound definition

Low-pitched sound during rapid ventricular filling

S3 alternate name

Ventricular gallop rhythm

Phase of S3

Rapid ventricular filling phase

Causes of S3 – Left sided

• Hypertensive crisis → Brain hemorrhage, Left ventricular failure

• Dilated cardiomyopathy → Alcohol ,Duchenne muscular dystrophy ,Myocarditis sequelae

• Congestive heart failure → severe anemia, viral myocarditis , PDA, VSD

Causes of S3 – CHF

• Severe anemia • Viral myocarditis • PDA • VSD

Cor pulmonale S3 cause

Right ventricular failure due to non-cardiogenic cause (COPD)

Chronic mitral regurgitation sound

S3 present

S4 heart sound definition

Sound due to atrial kick against a stiff ventricle

S4 alternate name

Atrial gallop rhythm

S4 heart sound occur mostly due to

Outflow tract obstruction due to any cause

Left sided S4 causes

• Aortic stenosis

• Hypertrophic cardiomyopathy (subvalvular stenosis)

• Hypertension

Right sided S4 causes

• Pulmonic stenosis

• Pulmonary artery hypertension

Cause of cor pulmonnale

COPD

Jugular venous pressure (JVP) definition

Reflects right atrial pressure and status

Preferred vein for JVP measurement

Internal jugular vein

JVP in obese patients (not accesible due to anatommical reason)

External jugular vein preferred

Normal JVP value

5–8 cm of H₂O from Angle of Louis

Normal JVP response to inspiration

Falls on deep inspiration

Kussmaul sign definition

Paradoxical rise of JVP on deep inspiration

Kussmaul sign seen in

• Constrictive pericarditis

• Restrictive cardiomyopathy

• Right side heart failure ( cor pulmonale-COPD , Pulmonary embolism, inferior wall MI )

Non-pulsatile raised JVP seen in

Cardiac tamponade

Causes of Kussmaul sign mnemonic

COP restricts right heart

Constrictive pericarditis cause

Pericardial calcification

Restrictive cardiomyopathy cause

Myocardial fibrosis

Right heart failure causes of Kussmaul

• Inferior wall MI

• Cor pulmonale (COPD)

• Acute cor pulmonale (pulmonary embolism)

In all condition JVP is increased and pulsatile except

cardiac tamponade ( non pulsatile elevated JVP )

a wave of JVP indicate

Atrial systole

c wave of JVP indicate

Bulging of tricuspid valve during isovolumetric contraction

x descent

Ejection phase and atrial relaxation (negative deflection)

v wave

Venous filling of right atrium

y descent

Rapid ventricular filling

Peak of v wave corresponds to

S2

Atrial systole ECG phase

Start of P wave to peak of R wave

Ventricular systole ECG phase

Peak of R wave to end of T wave

Ventricular diastole ECG phase

End of T wave to next P wave

Timing of S1

End of atrial systole

Timing of S2

End of ventricular systole

Ejection click timing

Between c wave and x descent

Ejection click significance

Opening of aortic and pulmonic valves

Opening snap timing

After S2

Opening snap indicates

Mitral or tricuspid valve opening

Isovolumetric contraction phase

• Starts with S1 • Ends with ejection click

Large a wave definition

Prominent a wave in JVP

Causes of large a wave

• Tricuspid stenosis • Pulmonic stenosis • Pulmonary artery hypertension (scleroderma) • TOF (subpulmonic stenosis)

Tricuspid stenosis murmur

Mid-diastolic murmur

Long standing mitral stenosis consequence

• Right ventricular hypertrophy • Pulmonary edema • Hypoxia • Pulmonary artery hypertension

Absent a wave seen in

Atrial fibrillation

Pulse in atrial fibrillation

Irregularly irregular

Cannon a wave definition

Intermittent large a waves due to AV dissociation

Frog sign

Another name for cannon a wave

AV dissociation causes

• Ventricular tachycardia • Junctional tachycardia with retrograde P wave • Complete heart block (Stokes-Adams syndrome)

Absent x descent seen in

Tricuspid regurgitation

Prominent v wave (cv wave)

Severe tricuspid regurgitation

Steep y descent indicates

Severe tricuspid regurgitation

Absent y descent indicates

Cardiac tamponade

Mechanism of tamponade

Impaired ventricular filling

Cardiac tamponade seen in

• Oat cell carcinoma lung • Extrapulmonary tuberculosis

Hemodynamic changes in tamponade

• Decreased ventricular filling • Decreased stroke volume • Decreased cardiac output • Decreased BP • Weak or absent pulse

Pulsus paradoxus definition

Disappearance of pulse during inspiration

Normal inspiratory SBP fall

< 10 mmHg

Tamponade inspiratory SBP fall

> 12 mmHg

Treatment of cardiac tamponade in Ca lung/TB

Echocardiography-guided pericardiocentesis

Treatment of tamponade in penetrating trauma

Emergency resuscitative thoracotomy

Low pressure cardiac tamponade

Diastolic collapse of right atrium → reduced atrial filling → reduced BP

Typical cardiac tamponade

Diastolic collapse of ventricles → severely reduced filling → severe hypotension

Steep x and absent y descent seen in

Cardiac tamponade

Steep x and y descent seen in

Constrictive pericarditis

Absent x and steep y descent seen in

Tricuspid regurgitation

Mnemonic for JVP patterns

Guy on a date – Steep prices at Connaught Place

Irregularly irregular pulse + loud diastolic sound + rapid y descent diagnosis

Constrictive pericarditis

Correct breathing instruction for pulsus paradoxus measurement

Breathe normally

Mid-diastolic murmur + prominent a wave diagnosis

Tricuspid stenosis

a wave corresponds to

Right atrial contraction