What are the 5 T's of pulmonary embolism (PE) cyanotic heart disease?

The 5 T's of Cyanotic Congenital Heart Disease

The 5 T's of cyanotic congenital heart disease are Tetralogy of Fallot, Transposition of the Great Arteries (TGA), Total Anomalous Pulmonary Venous Connection (TAPVC), Truncus Arteriosus, and Tricuspid valve abnormalities (including tricuspid atresia, stenosis, and Ebstein's anomaly). 1

Overview of the 5 T's

1. Tetralogy of Fallot

• Consists of four features: right ventricular hypertrophy, ventricular septal defect (VSD), overriding aorta, and subpulmonary stenosis 1
• Commonly associated with decreased pulmonary blood flow 1
• Presents with squatting, cyanotic spells, and no evidence of congestive heart failure 2
• Surgical correction is usually performed after 3 months of age with excellent prognosis in uncomplicated cases 1

2. Transposition of the Great Arteries (TGA)

• Characterized by ventriculoarterial discordance where the aorta arises from the right ventricle and the pulmonary artery from the left ventricle 3
• Typically presents in the neonatal period 2
• Associated with congestive heart failure with cyanosis 2
• Requires early recognition and intervention for good outcomes 4

3. Total Anomalous Pulmonary Venous Connection (TAPVC)

• Condition where all pulmonary veins drain into the systemic venous circulation rather than the left atrium 3
• Usually presents in the neonatal period 2
• Can be supracardiac, cardiac, infracardiac, or mixed type 5
• Accounts for approximately 10% of cyanotic congenital heart diseases 5

4. Truncus Arteriosus

• Single arterial trunk arising from the heart that supplies both systemic and pulmonary circulation 3
• Associated with increased pulmonary blood flow 3
• Represents about 10% of cyanotic congenital heart diseases 5
• Requires surgical intervention to separate pulmonary and systemic circulations 4

5. Tricuspid Valve Abnormalities

• Includes tricuspid atresia, stenosis, and Ebstein's anomaly 1
• Tricuspid atresia is characterized by complete absence of the tricuspid valve 1
• Ebstein's anomaly involves displacement of the tricuspid valve into the right ventricle 1
• Clinical presentation depends on three factors: status of the tricuspid valve, presence and size of a VSD, and whether great arteries are transposed or normally related 1

Clinical Implications

• Early recognition and timely management of these conditions is essential for good outcomes 2
• Multidetector CT angiography plays an important role in diagnosis and surgical planning 5
• Pathophysiology determines the clinical presentation of each condition 2
• Most of these conditions can be surgically corrected or effectively palliated with relatively low risk 4
• Continued follow-up after surgery is mandatory due to potential residual defects 4

Diagnostic Approach

• Clinical features and non-invasive laboratory studies are often sufficient for diagnosis 4
• Invasive cardiac catheterization is typically reserved for defining features not clearly identified by non-invasive studies or for catheter-based interventions 4
• Multidetector CT angiography provides valuable information about cardiac anatomy, great vessels, and associated anomalies 5
• Echocardiography remains the first-line imaging modality for initial assessment 4

Management Considerations

• Surgical correction timing varies by condition, with some requiring neonatal intervention (TGA, TAPVC) 2
• Palliative shunts may be necessary before definitive repair in some conditions 1
• Understanding the specific pathophysiology guides appropriate medical and surgical management 2
• Long-term follow-up is essential as residual defects may require repeat interventions 4