A 13 year old girl presents to the Emergency Department after a syncopal event at school.

She experienced a sudden loss of consciousness without preceding chest pain or dyspnoea and recovered spontaneously. She had no previous history of syncope.

Initial observations were stable.

ECG and chest radiography suggested right heart strain, prompting bedside cardiac ultrasound.

ECG

Chest Xray

 

The following clip shows her PLAX view followed by her PSAX then the 4 CV and then colour Doppler through her tricuspid valve in the 4CV

PLAX

Parasternal Long Axis (PLAX)

The PLAX view immediately demonstrated marked right ventricular enlargement.

Key findings included:

  • Right ventricle larger than expected
  • Flattening of the interventricular septum during both systole and diastole
  • Small, under-filled left ventricle
  • Reduced left ventricular filling due to right ventricular pressure overload

The septal flattening (“D-sign”) reflects elevated right ventricular pressure compressing the left ventricle.

PSAX

Parasternal Short Axis (PSAX)

The PSAX view showed:

  • Severe septal flattening
  • D-shaped left ventricle
  • Dilated right ventricle

The timing of septal flattening provides useful physiological information:

  • Systolic flattening suggests pressure overload.
  • Diastolic flattening suggests volume overload.
  • Flattening throughout the cardiac cycle, as seen here, indicates severe right ventricular pressure overload.

Apical Four-Chamber View

The four-chamber view confirmed:

  • Markedly enlarged right ventricle
  • Dilated right atrium
  • Small compressed left ventricle
  • Loss of the normal RV:LV ratio

Normally, the RV should measure approximately two-thirds the size of the LV. In this patient the RV exceeded LV size, a highly abnormal finding

Colour Doppler

Colour Doppler demonstrated significant tricuspid regurgitation.

Continuous-wave Doppler across the tricuspid regurgitant jet estimated the right ventricular systolic pressure at approximately 70 mmHg, consistent with severe pulmonary hypertension (assuming no pulmonary valve stenosis). RV systolic pressure can be estimated  from the tricuspid regurgitation jet (RVSP = 4 × TR velocity² + estimated RA pressure).

The patient was admitted under paediatric cardiology for definitive investigation and management.

Discussion

Pulmonary hypertension is now defined haemodynamically as a mean pulmonary artery pressure >20 mmHg measured at right heart catheterisation. In fetal circulation, the PAP is similar to that of the systemic circulation but after birth drops significantly to achieve levels similar to adults at  3 months of age. This definition therefore applies to children older than 3 months of age.

Understanding Pulmonary Hypertension in Children

Pulmonary hypertension (PH) is uncommon in children but carries significant morbidity and mortality if diagnosis is delayed.

Unlike adults, paediatric PH has a broader spectrum of causes.

Causes include:

  • Idiopathic pulmonary arterial hypertension
  • Congenital heart disease
  • Bronchopulmonary dysplasia
  • Congenital diaphragmatic hernia
  • Chronic lung disease
  • Down syndrome
  • Connective tissue disease
  • Portal hypertension
  • Chronic thromboembolic disease (rare)

Many children remain undiagnosed because symptoms are initially nonspecific.

Clinical Presentation

Symptoms may include:

  • Exertional dyspnoea
  • Fatigue
  • Exercise intolerance
  • Syncope or presyncope
  • Chest pain
  • Cyanosis
  • Failure to thrive in younger children
  • cough
  • Heart failure (uncommon)

Syncope is a particularly concerning symptom, often reflecting an inability of the right ventricle to increase cardiac output during exercise.

Presentation

The diagnosis of PH is often delayed in children because of the non specific symptoms . The most common misdiagnosis is asthma. Clinical presentation will depend on the age of the patient, the presence or absence of associated medical conditions, the severity of the pulmonary hypertension, and RV function.

POCUS Signs of Pulmonary Hypertension

When performing focused cardiac ultrasound, systematically assess:

✓ Right ventricular enlargement

✓ RV:LV ratio >1

✓ D-shaped left ventricle

✓ Septal flattening

✓ Right atrial enlargement

✓ Dilated pulmonary artery

✓ Tricuspid regurgitation

✓ Reduced TAPSE (RV systolic dysfunction)

✓ Dilated IVC with reduced inspiratory collapse

No single finding confirms pulmonary hypertension, but the combination strongly supports the diagnosis and should prompt formal echocardiography.

Emergency Department Management

Once pulmonary hypertension is suspected:

  • Obtain formal transthoracic echocardiography
  • Perform ECG and chest radiography
  • Measure BNP or NT-proBNP and perform lung ultrasound to look for pulmonary oedema
  • Investigate for underlying congenital heart or lung disease
  • Avoid systemic hypotension
  • Treat hypoxia aggressively
  • Discuss early with paediatric cardiology
  • Consider transfer to a tertiary centre experienced in pulmonary hypertension

Children with severe pulmonary hypertension can deteriorate rapidly, particularly during sedation, anaesthesia or positive-pressure ventilation.

Key Learning Points

🔹 Syncope in a child should always prompt consideration of pulmonary hypertension.

🔹 Right ventricular enlargement with septal flattening is one of the most important bedside echocardiographic clues.

🔹 The “D-shaped left ventricle” reflects right ventricular pressure overload.

🔹 Tricuspid regurgitation Doppler allows estimation of pulmonary artery pressure.

🔹 POCUS provides rapid bedside recognition, but definitive diagnosis still requires comprehensive echocardiography and right heart catheterisation.

Post revised July 2026