Truncus Arteriosus in Fetal Cardiology


Topic:

ফেটাল কার্ডিওলজিতে Truncus Arteriosus


🔹 Definition

Truncus arteriosus হলো একটি complex congenital heart disease যেখানে একটি single great artery হৃদপিণ্ড থেকে বের হয় এবং তা systemic, pulmonary ও coronary circulation-এ রক্ত সরবরাহ করে।

👉 Normally aorta এবং pulmonary artery আলাদা থাকে, কিন্তু truncus arteriosus-এ তারা পৃথকভাবে develop হয় না।


🔹 Embryology

Normal embryonic development-এ:
✔ Truncus arteriosus septation হয়ে
➡ Aorta এবং Pulmonary artery তৈরি হয়।

Truncus arteriosus এ:

✔ Conotruncal septation failure হয়।


🔹 Anatomy

Main Features:

✔ Single arterial trunk
✔ Large subtruncal VSD
✔ Single truncal valve
✔ Pulmonary arteries trunk থেকে arise করে


🔹 Physiology

কারণ systemic ও pulmonary circulation একই trunk share করে:

✔ Complete mixing of blood হয়
✔ Pulmonary overcirculation develops
✔ Heart failure হতে পারে


🔹 Classification (Collett & Edwards)

Type I

✔ Main pulmonary artery trunk থেকে arise করে

Type II

✔ Right ও left pulmonary artery posteriorly পৃথকভাবে arise করে

Type III

✔ Pulmonary arteries laterally পৃথকভাবে arise করে

Type IV

বর্তমানে pseudotruncus হিসেবে বিবেচিত


🔹 Associated Abnormalities

✔ DiGeorge syndrome (22q11 deletion)
✔ Right aortic arch
✔ Interrupted aortic arch
✔ Coronary anomalies


🔹 Fetal Echocardiographic Findings

🔹 Key Diagnostic Features

✔ Single great vessel overriding VSD
✔ Absence of separate pulmonary artery and aorta
✔ Large VSD
✔ Single semilunar valve


🔹 Four Chamber View

Findings:

✔ Often normal chamber size
✔ Large VSD may be visualized


🔹 Outflow Tract Views

Most important views

✔ Only one great artery identified
✔ Single vessel overriding interventricular septum


🔹 Three Vessel View (3VV)

Findings:

✔ Abnormal appearance
✔ Only one large vessel visualized


🔹 Color Doppler Findings

✔ Mixed systemic and pulmonary flow
✔ Truncal valve regurgitation may occur


🔹 Truncal Valve Assessment

Evaluate:
✔ Number of cusps
✔ Regurgitation
✔ Stenosis

Important:

✔ Significant truncal regurgitation worsens prognosis


🔹 Differential Diagnosis

Differentiate from:

DiseaseKey Difference
TOF with pulmonary atresiaSeparate aorta present
DORVTwo great arteries present
TGAParallel great arteries

🔹 Associated Genetic Syndrome

Strong association:

✔ 22q11 deletion syndrome

👉 Genetic counseling recommended


🔹 Prognosis

Depends on:
✔ Truncal valve function
✔ Associated anomalies
✔ Pulmonary blood flow

Without surgery:
❌ High mortality


🔹 Postnatal Management

✔ Early neonatal surgery required
✔ VSD closure
✔ RV-PA conduit repair


🔹 Surgical Timing

Usually:
✔ First few weeks of life


🔹 Important Fetal Counseling Points

Parents should be informed about:
✔ Need for surgery
✔ Possible genetic syndrome
✔ Neonatal cardiac care
✔ Long-term follow-up


🔹 Key Learning Points

✔ Truncus arteriosus = single arterial trunk
✔ Large VSD almost always present
✔ Best diagnosed in outflow tract views
✔ 3VV abnormal
✔ Frequently associated with 22q11 deletion


👨‍⚕️ ডা. মোহাম্মদ নিজাম উদ্দিন

এমবিবিএস, বিসিএস (স্বাস্থ্য), এমডি (কার্ডিওলজি)
কার্ডিয়াক ইন্টারভেনশনে পোস্ট ডক্টরাল ট্রেনিং
ফেটাল কার্ডিওলজি ও ইন্টারভেনশনে অ্যাডভান্সড ফেলোশিপ

সহযোগী অধ্যাপক ও সিনিয়র কনসালট্যান্ট (কার্ডিওলজি)
ক্লিনিক্যাল ও ইন্টারভেনশনাল কার্ডিওলজিস্ট
বাংলাদেশের অগ্রণী ফেটাল কার্ডিওলজিস্ট ও ফেটাল ইকোকার্ডিওগ্রাফি বিশেষজ্ঞ


Truncus Arteriosus in Fetal Cardiology


🔹 Definition

Truncus arteriosus is a complex congenital heart disease in which a single arterial trunk arises from the heart and supplies systemic, pulmonary, and coronary circulation.

Normally, the aorta and pulmonary artery develop separately, but in truncus arteriosus, separation fails.


🔹 Embryology

Normally:
✔ The truncus arteriosus septates into:

  • Aorta
  • Pulmonary artery

In truncus arteriosus:

✔ Failure of conotruncal septation occurs.


🔹 Anatomy

Main Features:

✔ Single arterial trunk
✔ Large subtruncal VSD
✔ Single truncal valve
✔ Pulmonary arteries arise from truncal vessel


🔹 Physiology

Because pulmonary and systemic circulations share a common trunk:

✔ Complete blood mixing occurs
✔ Pulmonary overcirculation develops
✔ Congestive heart failure may occur


🔹 Classification (Collett & Edwards)

Type I

✔ Main pulmonary artery arises from truncus

Type II

✔ Right and left pulmonary arteries arise separately posteriorly

Type III

✔ Pulmonary arteries arise separately laterally


🔹 Associated Abnormalities

✔ DiGeorge syndrome (22q11 deletion)
✔ Right aortic arch
✔ Interrupted aortic arch
✔ Coronary anomalies


🔹 Fetal Echocardiographic Findings

Key Features:

✔ Single overriding great vessel
✔ Large VSD
✔ Absence of separate pulmonary artery and aorta
✔ Single semilunar valve


🔹 Four Chamber View

Findings:

✔ Often normal chamber symmetry
✔ Large VSD may be visible


🔹 Outflow Tract Views

Most important diagnostic views

✔ Only one great artery identified
✔ Single vessel overriding septum


🔹 Three Vessel View (3VV)

Findings:

✔ Abnormal
✔ Only one large vessel visualized


🔹 Color Doppler

✔ Mixed systemic and pulmonary flow
✔ Possible truncal valve regurgitation


🔹 Truncal Valve Assessment

Assess:
✔ Number of cusps
✔ Regurgitation
✔ Stenosis

Significant truncal regurgitation worsens prognosis.


🔹 Differential Diagnosis

ConditionDifference
TOF with pulmonary atresiaSeparate aorta present
DORVTwo great arteries
TGAParallel great arteries

🔹 Genetic Association

Strong association with:
✔ 22q11 deletion syndrome

Genetic counseling is recommended.


🔹 Prognosis

Depends on:
✔ Truncal valve function
✔ Associated anomalies
✔ Pulmonary blood flow

Without surgery:
❌ High mortality


🔹 Postnatal Management

✔ Early neonatal surgical repair
✔ VSD closure
✔ RV-to-PA conduit placement


🔹 Important Counseling Points

Parents should understand:
✔ Need for surgery
✔ Possible genetic syndromes
✔ Neonatal cardiac care
✔ Lifelong follow-up


🔹 Key Learning Points

✔ Truncus arteriosus has a single arterial trunk
✔ Large VSD almost always present
✔ Outflow tract views are essential
✔ 3VV is abnormal
✔ Frequently associated with 22q11 deletion


👨‍⚕️ Dr. Mohammed Nizam Uddin

MBBS, BCS (H), MD (Cardiology)
Post Doctoral Training in Cardiac Intervention
Advanced Fellowship in Fetal Cardiology & Intervention

Associate Professor & Senior Consultant (Cardiology)
Clinical & Interventional Cardiologist
Pioneer Fetal Cardiologist & Fetal Echocardiography Expert

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