PE23.10 - Cardiovascular System Examination in Children and Infants

Overview: Approach to the Pediatric CVS Exam

1. Inspection of the Precordium

Precordial Bulge

• Cause: Long-standing cardiomegaly causing the compliant chest wall (especially in infants) to expand outward. This is a pediatric-specific finding because the bony thorax in young children is soft and cartilaginous.
• Significance:
  • Indicates chronic cardiomegaly - the heart has been enlarged for a prolonged period
  • Seen in large left-to-right shunts (VSD, PDA, ASD with significant shunting)
  • Seen in chronic rheumatic heart disease, cardiomyopathies
  • A right-sided bulge suggests right ventricular (RV) enlargement
  • A left-sided or generalized bulge suggests left ventricular (LV) enlargement or biventricular enlargement
• Note: Adult chests are too rigid to develop this - it is almost exclusively a pediatric finding

Pulsations in the Precordium

• Left-to-right shunts with large pulmonary blood flow
• High-output states (anemia, fever, thyrotoxicosis)
• Anxiety/excitement in thin-chested children

2. Jugular Venous Pressure (JVP) - Pediatric Specifics

Assessment Technique

• Age restriction: Formal JVP assessment is only reliable and routinely performed in children older than 8 years
• The internal jugular vein (IJV) is used (not the external jugular vein, which is more easily visible but has valves and is unreliable)
• Position: semi-recumbent at 45°, head turned slightly to the left
• The IJV runs between the medial clavicle and the earlobe, under the sternocleidomastoid
• Measurement: Vertical distance from the sternal angle to the top of the venous pulsation column - normal is ≤3 cm (equivalent to Right Atrial Pressure = vertical ht. of blood column + 5 cm of H₂O; normal JVP < 8 cm H₂O or < 6 mmHg)
• The IJV shows a double waveform pulsation (a and v waves), distinguishing it from carotid artery pulsation

Why JVP is Difficult in Infants and Young Children

1. Short, fat neck - the IJV is anatomically inaccessible
2. Inability to cooperate - crying, squirming, head-turning all raise intrathoracic and thus venous pressure artifactually
3. High resting heart rate - individual waveforms (a, c, x, v, y) cannot be discerned at rates >100 bpm
4. In infants, hepatomegaly is a surrogate: Right atrial hypertension causes hepatomegaly before it causes visible JVD. A liver edge >3 cm below the right costal margin is the equivalent indicator of right-sided venous congestion in infants

JVP Waveform Analysis (when assessable - older children)

Clinical Significance of JVP in Children

3. Palpation of the Precordium

Apex Beat

• Normal location by age:
  • Neonate/infant (<2 years): 4th ICS, lateral to mid-clavicular line
  • 2-7 years: 4th-5th ICS, mid-clavicular line

  • 7 years: 5th ICS, mid-clavicular line (adult position)

• Lateral displacement: LV dilatation (large VSD, MR, DCM)
• Sustained/heaving impulse: LV hypertrophy (AS, hypertension)
• Tapping apex: Palpable S1 - mitral stenosis

Left Parasternal Heave

• Palpate with the heel of the hand along the left sternal border
• Positive heave (lift): RV enlargement/hypertrophy - seen in pulmonary hypertension, large ASD, PS, TOF

Thrills

• Systolic thrill at LUSB: PS, AS, large VSD
• Diastolic thrill at apex: Mitral stenosis (rare in children)
• Continuous thrill: PDA

4. Percussion - Relevance in Pediatric Examination

Why Percussion Has Limited Utility in Children

1. Chest X-ray is more accurate: The cardiothoracic ratio (CTR) on CXR is a far more reliable and reproducible method of assessing cardiac size. CTR >0.55 in children (>0.60 in infants) indicates cardiomegaly.
2. Small chest dimensions: The compact thorax of infants/toddlers makes demarcating cardiac dullness from lung resonance unreliable.
3. Overlying lung tissue variability: Lung hyperinflation (as in bronchiolitis, asthma) artificially narrows the area of cardiac dullness by percussion.
4. ECG and echo are more informative: These modalities provide direct chamber dimension data.

When Percussion Is Still Useful

• Pleural effusion detection: Stony dull percussion note at the lung base can indicate pleural effusion (seen in heart failure, post-cardiac surgery)
• Pericardial effusion: Gross enlargement of the cardiac shadow can be appreciated as a wide area of cardiac dullness
• Dextrocardia: Percussion helps confirm cardiac position when echocardiography is unavailable - dullness on the right with resonance on the left
• Hepatomegaly: Percussion of the right upper quadrant defines the liver span - important surrogate for right heart congestion in infants where JVP is unreliable

5. Auscultation

Practical Tips

• Use a pediatric stethoscope with bell and diaphragm
• Bell (light pressure): detects low-frequency sounds - S3, S4, mid-diastolic murmurs (e.g., mitral stenosis rumble)
• Diaphragm (firm pressure): detects high-frequency sounds - S1, S2, systolic murmurs, pericardial rub
• In infants, perform auscultation first before any distressing maneuvers
• At high heart rates (>160 bpm in neonates), it can be difficult to distinguish systole from diastole - palpate the pulse simultaneously to orient yourself

Auscultation Areas in Children

1. Mitral area (apex) - 4th/5th ICS MCL
2. Tricuspid area - 4th ICS left sternal border (LSB)
3. Pulmonary area - 2nd ICS left sternal border
4. Aortic area - 2nd ICS right sternal border
5. Erb's point - 3rd ICS LSB (useful for early diastolic murmurs of AR and PR)
6. Axilla - radiation of MR
7. Back - radiation of PS, coarctation, PDA

Heart Sounds

S1 (First Heart Sound)

• Closure of mitral (M1) and tricuspid (T1) valves
• M1 precedes T1; normally heard as a single sound
• Best heard at the apex and LLSB
• Loud S1: High output states, MS with pliable valve, short PR interval
• Soft S1: Poor LV function, MR, long PR interval
• Variable S1: Complete heart block, AF

S2 (Second Heart Sound)

• Closure of aortic (A2) and pulmonary (P2) valves
• Best heard at the base (2nd ICS)
• Physiological splitting of S2: A2 precedes P2; splitting increases on inspiration (increased RV filling → delayed P2) - normal finding in children and adolescents
• Wide fixed split S2: ASD (hallmark finding)
• Wide variable split: RBBB, PS, RV failure
• Narrow split / single S2: Pulmonary hypertension (P2 loud and early), severe AS, Eisenmenger syndrome
• Reversed (paradoxical) split: LBBB, severe AS

S3 (Third Heart Sound)

• Low-frequency sound at the apex, heard in early diastole (during rapid ventricular filling)
• Can be normal in children (physiological S3) - especially thin, athletic children
• Pathological S3: Dilated cardiomyopathy, large left-to-right shunt (e.g., large VSD), heart failure
• Best heard with the bell of the stethoscope

S4 (Fourth Heart Sound)

• Low-frequency presystolic sound (atrial gallop)
• Always pathological in children
• Indicates reduced ventricular compliance
• Seen in: severe hypertension, severe AS, HCM, cardiomyopathy

Gallop Rhythms

• S3 gallop (proto-diastolic): Suggests ventricular dysfunction or volume overload
• S4 gallop (presystolic/atrial): Suggests stiff, non-compliant ventricle
• Summation gallop: When S3 + S4 fuse (seen in tachycardia) - sounds like a horse's gallop

Murmurs: Key Features to Assess

• Grade I: Very faint; only heard in quiet room
• Grade II: Faint but easily heard
• Grade III: Moderate; no thrill
• Grade IV: Loud; thrill present
• Grade V: Very loud; heard with stethoscope barely on chest
• Grade VI: Heard without stethoscope

Innocent vs. Pathological Murmurs

• Grade III/IV or higher with thrill
• Diastolic or continuous murmur (almost always pathological)
• Abnormal S2 (fixed split, loud P2, single S2)
• Pan-systolic or early systolic murmur
• Associated symptoms (cyanosis, poor weight gain, syncope, exercise intolerance)
• Radiation to axilla or back
• Harsh/blowing character

Common Murmurs in Children

Pericardial Friction Rub

• Scratchy, to-and-fro sound heard in pericarditis
• Best heard at left sternal border with patient leaning forward
• Three components: atrial systole, ventricular systole, ventricular diastole
• Unlike pleural rub: persists when breath is held

6. Other Systems to Complete the CVS Examination

Peripheral Pulses

• Brachial (infants), radial (older children)
• Femoral pulses: Always palpate - radio-femoral delay indicates coarctation of the aorta (essential to not miss)
• Pulse character: Collapsing (PDA, AR), bounding (large shunts), weak/absent (coarctation, tamponade)

Blood Pressure

• Four-limb BP in suspected coarctation: >20 mmHg difference between upper and lower limbs is significant
• Age-appropriate cuff size is mandatory

Respiratory System

• Tachypnea is the earliest sign of cardiac decompensation in infants
• Pulmonary rales indicate left heart failure (less common in infants due to adaptive lymphatic drainage)
• Pleural effusion (stony dull, absent breath sounds) suggests decompensated heart failure

Abdomen

• Hepatomegaly (>3 cm below RCM in infants; >2 cm in children): surrogate for raised JVP and right heart congestion
• Splenomegaly: infective endocarditis, congestive splenomegaly
• Pulsatile liver: severe TR, markedly elevated right heart pressures
• Ascites: severe right heart failure, constrictive pericarditis

Periphery

• Clubbing: Cyanotic CHD, infective endocarditis
• Cyanosis: Central (tongue/mucous membranes) or peripheral
• Edema: Dependent (sacral in infants who lie flat, ankle in older children); periorbital in infants
• Splinter hemorrhages: IE
• Osler nodes / Janeway lesions: IE

Summary Framework for the Exam

General → Vitals (HR, RR, BP 4 limbs, SpO₂) → Peripheral signs (clubbing, cyanosis, edema)
→ Pulses (radial, femoral, character)
→ JVP (>8 years only; use hepatomegaly as surrogate in infants)
→ Precordium Inspection (bulge, visible pulsations, scars)
→ Palpation (apex beat, parasternal heave, thrills, pulsations)
→ Percussion (limited role; mainly for pleural effusion, hepatomegaly, dextrocardia)
→ Auscultation (S1, S2, added sounds, murmurs, rub)
→ Lung bases (rales, effusion)
→ Abdomen (hepatomegaly, splenomegaly)

• Precordial bulge = chronic cardiomegaly in children; adult chests are too rigid for this
• JVP is not reliably assessable below age 8; use hepatomegaly as the equivalent marker of right heart congestion in infants
• Percussion has limited utility; CXR, ECG, and echo are far more informative
• S3 can be physiological in children; S4 is always pathological
• Fixed split S2 = ASD until proven otherwise
• Loud P2 = pulmonary hypertension
• Disappearance of a murmur on standing is the strongest predictor of an innocent murmur (98% PPV)
• Always palpate femoral pulses to exclude coarctation