A persistent connection between the aorta and pulmonary artery due to the failure of the ductus arteriosus to close after birth.
Normal Fetal Circulation:
- Before
birth, the ductus arteriosus allows blood to bypass the
lungs.
- After
birth, it should close within 24-48 hours.
- If
it remains open, it causes left-to-right shunting,
increasing blood flow to the lungs.
More Common in Females (2:1 ratio)
Mnemonic: "PDA = Persistent Ductus Open"
CAUSES OF PDA
• Prematurity (Most Common Cause)
• Congenital Rubella Syndrome
• High Altitude Births (Hypoxia Delays Closure)
• Genetic Conditions (Down Syndrome, CHD Syndromes)
Mnemonic: "PDA = P.R.O.B.L.E.M."
- Prematurity
- Rubella
Infection
- Oxygen
Deficiency (Hypoxia)
- Birth at
High Altitude
- Low Birth
Weight
- Endocardial
Cushion Defects
- Maternal
Diabetes
SYMPTOMS OF PDA
• Small PDA (No Symptoms, Found by Chance)
• Large PDA (Heart Overload & Symptoms Appear by 6-10 Weeks)
- Frequent Chest Infections
- Breathlessness (Dyspnea, Tachypnea)
- Failure to Thrive (Poor Weight Gain)
- Bounding Pulse & Wide Pulse
Pressure
Mnemonic: "PDA = PINK BABY with Pounding Pulses"
HEART MURMUR IN
PDA
- Continuous "Machinery" Murmur → Heard best in the 2nd left intercostal space (below clavicle)
- Bounding Peripheral Pulses → Due to high pulse pressure
- Thrill May Be Felt in Thin Chest Babies
Mnemonic: "M.A.C.H.I.N.E." Murmur
- Murmur
Continuous
- At 2nd ICS
Left
- Clubbing (If
Eisenmenger’s Develops)
- High Pulse
Pressure
- Increased LV
Workload
- Not Normal
in Adults
- Echo
Confirms Diagnosis
COMPLICATIONS OF
PDA
• Heart Failure (Due to Excess Blood Flow to Lungs)
• Pulmonary Hypertension (If Untreated for Years)
• Eisenmenger’s Syndrome (Shunt Reversal → Cyanosis in Lower Limbs)
• Endocarditis (Infection in the Heart)
Mnemonic: "H.P.E.E." (PDA Complications)
- Heart
Failure
- Pulmonary
Hypertension
- Eisenmenger’s
Syndrome
- Endocarditis
DIAGNOSIS OF PDA
- ECG → Normal or Left Ventricular Hypertrophy (LVH)
- Chest X-ray → Cardiomegaly, Enlarged Pulmonary Arteries
- Echocardiography (ECHO – Best Test!) → Confirms PDA Size & Blood Flow
- Doppler Color Flow Imaging → Shows Left-to-Right Shunting
Mnemonic: "ECHO-X" (Tests for PDA)
- ECHO → Best
Test
- Chest X-ray
→ Enlarged Heart & Pulmonary Arteries
- Holter
Monitor → If Arrhythmia Suspected
- Oxygen Check
(Pulse Oximetry)
TREATMENT OF PDA
1. MEDICAL
TREATMENT
- Indomethacin or Ibuprofen (NSAIDs) → Closes PDA
- Used in Neonates (First Week of Life)
2. SURGICAL
CLOSURE
If PDA is Large or Symptoms Persist
Options:
- Catheter-Based Coil Closure (Less
Invasive)
- Surgical Ligation (If Needed)
Mnemonic: "I.C.E." (Treatment of PDA)
- Indomethacin
(Closes PDA)
- Catheter
Closure
- Endocarditis
Prevention
CONTRAINDICATIONS
FOR PDA CLOSURE
- Eisenmenger’s Syndrome (Irreversible Pulmonary Hypertension)
- Severe Right Heart Failure
Mnemonic: "Eisenmenger = End of Closure"
PROGNOSIS OF PDA
- Small PDA → Closes on its own (Excellent Outcome)
- Large PDA → Good if Treated Early
- Untreated Large PDA → Leads to Pulmonary Hypertension & Heart Failure
Mnemonic: "PDA = Persistent but Fixable"
FINAL REVISION WITH MNEMONICS
- PDA = "Persistent Ductus Open"
- Causes = "P.R.O.B.L.E.M." (Prematurity, Rubella, Oxygen Deficiency, Birth Altitude, Low Birth Weight, Endocardial Defects, Maternal Diabetes)
- Symptoms = "PDA = PINK BABY with Pounding Pulses"
- Murmur = "M.A.C.H.I.N.E." (Continuous Murmur, Wide Pulse Pressure)
- Complications = "H.P.E.E." (Heart Failure, Pulmonary HTN, Eisenmenger’s, Endocarditis)
- Diagnosis = "ECHO-X" (ECHO, X-ray, Holter, Oxygen Check)
- Treatment = "I.C.E." (Indomethacin, Catheter Closure, Endocarditis Prevention)
- Closure Contraindication = "Eisenmenger = End of Closure"
