ফেটাল কার্ডিওলজিতে Ductus Arteriosus
🔹 Introduction
Ductus arteriosus হলো fetal circulation-এর একটি অত্যন্ত গুরুত্বপূর্ণ vascular structure, যা pulmonary artery কে descending aorta-এর সাথে সংযুক্ত করে।
👉 এটি fetal life-এ pulmonary circulation bypass করতে সাহায্য করে।
🔹 Embryology
✔ ৬th aortic arch থেকে develop হয়
✔ Left sixth arch persist করে ductus arteriosus তৈরি করে
🔹 Anatomy of Ductus Arteriosus
Connection:
✔ Main pulmonary artery / left pulmonary artery
⬇
✔ Descending thoracic aorta
Position:
✔ Left side of trachea
✔ Aortic arch-এর anterior এবং slightly superior
🔹 Function in Fetal Circulation
Fetal lung collapsed থাকে এবং pulmonary vascular resistance (PVR) বেশি থাকে।
তাই:
✔ RV output-এর অধিকাংশ ductus arteriosus দিয়ে descending aorta-তে যায়
👉 Approximately 85–90% RV output ductus দিয়ে প্রবাহিত হয়।
🔹 Physiological Importance
✔ Pulmonary circulation bypass
✔ Systemic circulation maintain
✔ Placental oxygen delivery support
🔹 Ductal Flow Direction
Normal:
✔ Right-to-left shunt
(Pulmonary artery → Aorta)
কারণ:
✔ High pulmonary resistance
✔ Low systemic placental resistance
🔹 Sonographic Evaluation
Standard View:
Ductal Arch View
Appearance:
✔ “Hockey stick” shape
🔹 Structures Seen in Ductal Arch
✔ Main pulmonary artery
✔ Ductus arteriosus
✔ Descending aorta
🔹 Differentiation from Aortic Arch
| Ductal Arch | Aortic Arch |
|---|---|
| Smooth curve | Candy cane shape |
| No head-neck vessels | Head-neck branches present |
| Origin from PA | Origin from LV |
🔹 Color Doppler Findings
Normal:
✔ Laminar antegrade flow
✔ No turbulence
🔹 Normal Doppler Parameters
Peak systolic velocity:
✔ Approximately 0.6–1.4 m/s
Pulsatility:
✔ Low resistance pattern
🔹 Closure After Birth
জন্মের পরে:
✔ Pulmonary resistance কমে যায়
✔ Oxygen tension বৃদ্ধি পায়
ফলে ductus constrict হয়ে:
✔ Functional closure → 24–48 hr
✔ Anatomical closure → কয়েক সপ্তাহ
🔹 Abnormalities of Ductus Arteriosus
1️⃣ Ductal Constriction
Causes:
✔ NSAIDs
✔ Indomethacin
✔ Polyphenol-rich food
Findings:
✔ Turbulent high-velocity flow
✔ RV enlargement
✔ Tricuspid regurgitation
2️⃣ Premature Closure
Complications:
✔ Right heart failure
✔ Hydrops fetalis
✔ Fetal demise
3️⃣ Patent Ductus Arteriosus (Postnatal)
জন্মের পরে ductus persist করলে PDA হয়।
🔹 Clinical Importance in CHD
Certain CHD are duct-dependent:
✔ Pulmonary atresia
✔ Critical coarctation
✔ HLHS
✔ TGA
👉 Ductus life-saving structure হতে পারে।
🔹 Important Fetal Echo Points
✔ Always assess ductal arch
✔ Compare with aortic arch
✔ Use color Doppler
✔ Assess ductal size and flow
🔹 Key Learning Points
✔ Ductus arteriosus is essential in fetal circulation
✔ Connects pulmonary artery to descending aorta
✔ Best visualized in ductal arch view
✔ Normal flow is right-to-left
✔ Ductal abnormalities can cause severe fetal compromise
👨⚕️ 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
Topic:
Ductus Arteriosus in Fetal Cardiology
🔹 Introduction
The ductus arteriosus is a vital vascular structure in fetal circulation connecting the pulmonary artery to the descending aorta.
👉 It allows blood to bypass the fetal lungs.
🔹 Embryology
✔ Develops from the left sixth aortic arch
🔹 Anatomy
Connection:
✔ Main pulmonary artery
⬇
✔ Descending thoracic aorta
Position:
✔ Left side of trachea
🔹 Function in Fetal Circulation
Because fetal pulmonary vascular resistance is high:
✔ Most RV output passes through ductus arteriosus into descending aorta.
👉 Approximately 85–90% of RV output traverses the ductus.
🔹 Physiological Role
✔ Bypasses lungs
✔ Maintains systemic circulation
✔ Supports placental oxygen delivery
🔹 Flow Direction
Normal:
✔ Right-to-left shunt
(Pulmonary artery → Aorta)
🔹 Sonographic Evaluation
Best View:
Ductal Arch View
Appearance:
✔ Hockey stick shape
🔹 Structures Seen
✔ Main pulmonary artery
✔ Ductus arteriosus
✔ Descending aorta
🔹 Ductal Arch vs Aortic Arch
| Ductal Arch | Aortic Arch |
|---|---|
| Smooth curve | Candy cane shape |
| No head-neck vessels | Branch vessels present |
| Origin from PA | Origin from LV |
🔹 Doppler Findings
Normal:
✔ Laminar antegrade flow
✔ No turbulence
🔹 Doppler Velocities
✔ Peak systolic velocity ≈ 0.6–1.4 m/s
🔹 Closure After Birth
After delivery:
✔ Pulmonary resistance falls
✔ Oxygen tension rises
Result:
✔ Functional closure within 24–48 hours
🔹 Abnormalities
1️⃣ Ductal Constriction
Causes:
✔ NSAIDs
✔ Indomethacin
✔ Polyphenol-rich food
Findings:
✔ High velocity turbulent flow
✔ RV enlargement
✔ TR
2️⃣ Premature Closure
Complications:
✔ Right heart failure
✔ Hydrops fetalis
✔ Fetal death
3️⃣ Patent Ductus Arteriosus (Postnatal)
Persistent ductus after birth results in PDA.
🔹 Importance in Congenital Heart Disease
Several CHD are duct-dependent:
✔ Pulmonary atresia
✔ Critical coarctation
✔ HLHS
✔ TGA
👉 The ductus may become life-saving.
🔹 Key Fetal Echo Points
✔ Always evaluate ductal arch
✔ Compare with aortic arch
✔ Use color Doppler
✔ Assess size and flow pattern
🔹 Summary
✔ Essential component of fetal circulation
✔ Connects pulmonary artery to descending aorta
✔ Best visualized in ductal arch view
✔ Normal flow is right-to-left
✔ Abnormal ductal physiology may severely compromise fetus
👨⚕️ 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