Cor triatriatum
21. Cor Triatriatum is a congenital condition where which heart chamber is divided into two?
22. What embryologic structure is believed to cause Cor Triatriatum if it fails to resorb?
23. Cor Triatriatum sinister involves which atrium?
24. Which imaging modality is most definitive for diagnosing Cor Triatriatum?
25. What is the usual clinical presentation of Cor Triatriatum in adults?
| 🔢 # | Cor triatriatum🩺 Key Point |
|---|---|
| 1️⃣ | Cor Triatriatum is a rare congenital cardiac anomaly. |
| 2️⃣ | The left atrium is divided into two chambers by a fibromuscular membrane. |
| 3️⃣ | This creates a triatrial heart (hence “triatriatum”). |
| 4️⃣ | Cor Triatriatum Sinistrum affects the left atrium; more common than dextrum. |
| 5️⃣ | Cor Triatriatum Dextrum is when the right atrium is partitioned — very rare. |
| 6️⃣ | Embryologically, failure of resorption of the common pulmonary vein leads to this defect. |
| 7️⃣ | The pulmonary veins drain into the proximal (posterior) chamber. |
| 8️⃣ | The distal (anterior) chamber communicates with the mitral valve. |
| 9️⃣ | The obstructive membrane behaves physiologically like mitral stenosis. |
| 🔟 | Symptoms include dyspnea, orthopnea, hemoptysis, and failure to thrive in infants. |
| 1️⃣1️⃣ | Auscultation may reveal a mid-diastolic murmur mimicking mitral stenosis. |
| 1️⃣2️⃣ | Can be associated with other congenital defects like ASD, TAPVC, or PDA. |
| 1️⃣3️⃣ | ECG findings may show left atrial enlargement and atrial arrhythmias. |
| 1️⃣4️⃣ | Chest X-ray may reveal pulmonary venous congestion or cardiomegaly. |
| 1️⃣5️⃣ | Echocardiography is the gold standard for diagnosis. |
| 1️⃣6️⃣ | CT/MRI may be used for surgical planning or complex anatomy. |
| 1️⃣7️⃣ | Symptomatic cases require surgical resection of the fibromuscular membrane. |
| 1️⃣8️⃣ | Prognosis is excellent post-surgery if no other major anomalies are present. |
| 1️⃣9️⃣ | It may present in adulthood if the orifice in the membrane is large enough (delayed onset). |
| 2️⃣0️⃣ | Differentiation from mitral stenosis or supravalvular mitral ring is crucial. |
🫀 Short Q&A Set — Cor Triatriatum (5-line answers)
🔻 Q1. What is Cor Triatriatum?
Cor Triatriatum is a rare congenital cardiac anomaly.
The left atrium is divided into two chambers by a fibromuscular membrane.
It mimics mitral stenosis physiologically.
The pulmonary veins drain into the proximal chamber.
Blood must pass through a fenestration to reach the true left atrium.
🔻 Q2. What are the types of Cor Triatriatum?
There are two main types: Cor Triatriatum Sinistrum and Dexter.
Sinistrum involves the left atrium and is more common.
Dexter affects the right atrium, extremely rare.
Classification depends on location and venous drainage pattern.
Sinistrum often presents with pulmonary venous obstruction.
🔻 Q3. What causes Cor Triatriatum to develop?
It results from incomplete incorporation of the common pulmonary vein into the left atrium.
This leads to a membrane that divides the atrial chamber.
The exact embryological failure is uncertain.
It’s a developmental arrest in early fetal life.
It may coexist with other congenital heart defects.
🔻 Q4. What are common symptoms of Cor Triatriatum?
Symptoms depend on the size of the fenestration in the membrane.
Infants may present with tachypnea, poor feeding, and cyanosis.
Older children or adults may have dyspnea, hemoptysis, or fatigue.
It can be asymptomatic if the membrane is widely fenestrated.
Symptoms resemble mitral stenosis or pulmonary venous obstruction.
🔻 Q5. How is Cor Triatriatum diagnosed?
Echocardiography (especially transesophageal) is the primary tool.
It shows the membrane dividing the left atrium.
Color Doppler reveals turbulent flow across the fenestration.
Cardiac MRI or CT may be used in complex cases.
Cardiac catheterization helps assess pressure gradients.
🔻 Q6. What are the key echocardiographic findings?
Presence of a thin membrane within the left atrium.
Pulmonary veins drain into a chamber proximal to the membrane.
Color Doppler shows restricted flow through fenestration.
Gradient mimics mitral valve stenosis.
TEE provides better spatial resolution than transthoracic echo.
🔻 Q7. How is Cor Triatriatum differentiated from mitral stenosis?
Mitral valve appears normal in cor triatriatum.
Obstruction is above the mitral valve, not at leaflet level.
Echocardiography reveals a dividing membrane.
There’s no leaflet thickening or fusion.
Also, younger age of presentation suggests congenital origin.
🔻 Q8. What is the treatment of Cor Triatriatum?
Surgical resection of the membrane is the definitive treatment.
Done via open-heart surgery with cardiopulmonary bypass.
Indicated when symptoms or pressure gradient are significant.
Prognosis post-surgery is usually excellent.
Balloon dilation is rarely attempted in select cases.
🔻 Q9. What are complications of untreated Cor Triatriatum?
Persistent obstruction leads to pulmonary hypertension.
Right heart failure and cyanosis may develop.
There’s risk of pulmonary edema and atrial arrhythmias.
Failure to thrive in infants may be seen.
Severe cases can result in early mortality if uncorrected.
🔻 Q10. Can Cor Triatriatum be associated with other anomalies?
Yes, often seen with ASDs, PAPVR, or persistent left SVC.
Also associated with AV canal defects in some syndromes.
The coexisting defects may complicate clinical presentation.
Combined anomalies can influence surgical planning.
Careful imaging is essential before intervention.
