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  • History of either cyanosis (70%) or congestive heart failure (30%)

  • Cyanotic patient with absent right ventricular impulse and prominent left ventricular impulse

  • Oligemic lung fields, right atrial and left ventricular prominence without right ventricular enlargement in retrosternal air space on chest radiograph

  • Evidence of left ventricular hypertrophy, absent or atretic tricuspid valve, atrial septal defect (ASD), small right ventricle


  • Includes a spectrum of morphologic tricuspid valve abnormalities

  • Survival requires the presence of an interatrial communication, such as a patent foramen ovale or ASD

  • Other associated cardiac defects:

    • – Ventricular septal defects (VSDs) may result in right ventricular outflow tract obstruction

    • – Patent ductus arteriosus

    • – Transposition of the great arteries

    • – Truncus arteriosus

    • – Double-outlet right or left ventricle

    • – Anomalous entry of the coronary sinus into the left atrium

    • – Coarctation of the aorta

  • The left ventricle functions as a univentricle and receives the entire systemic, coronary, and pulmonary venous return

  • Congestive heart failure may develop in the setting of increased pulmonary blood flow



  • The clinical presentation depends on the magnitude of pulmonary blood flow

  • Neonates with reduced pulmonary blood flow present early with profound cyanosis

  • Infants with increased pulmonary blood flow may present later with symptoms of congestive heart failure (dyspnea, fatigue, and difficulty feeding); cyanosis may or may not be present

  • Other symptoms:

    • – Recurrent respiratory tract infections

    • – Failure to thrive


Reduced pulmonary blood flow:

  • Tachypnea

  • Central cyanosis

  • Normal pulses

  • Holosystolic murmur of a VSD at the lower sternal border

  • Systolic ejection murmur (or no murmur) and single S2 in patients with pulmonary atresia

Increased pulmonary blood flow:

  • Minimal or absent cyanosis

  • Elevated jugular venous pressure

  • Hyperdynamic precordial impulse

  • Single or split S2

  • S3 may be present

  • Holosystolic murmur of a VSD at the lower sternal border

  • Mid-diastolic rumble at the apex due to increased flow across the mitral valve

  • Pulmonary rales and/or peripheral edema may be present


  • Ebstein’s anomaly with intermittent cyanosis

  • Pulmonary atresia with intact ventricular septum

  • Complete transposition of the great arteries

  • Other causes of cyanosis and heart failure



  • Arterial blood gases and pulse oximetry: demonstrate oxygen desaturation

  • Microcytic anemia in patients who have had chronic phlebotomy without iron replacement

  • Coagulation abnormalities

  • Hyperuricemia


  • Right atrial enlargement

  • Abnormal superior QRS vector (usually left-axis deviation in the frontal plane) or, less commonly, normal axis or right-axis deviation

  • Left ventricular hypertrophy

  • Decreased right ventricular forces

  • Atrial arrhythmias occasionally seen in older ...

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