A hole in the septum between the atria (upper heart chambers), allowing left-to-right shunting of blood.
Most Common in Females (2:1 Female-to-Male Ratio)
Types of ASD:
- Ostium Secundum (Most Common) → Defect in the Fossa Ovalis (former Foramen Ovale).
- Ostium Primum → Associated with cleft mitral valve.
Mnemonic: "ASD = Atria’s Septal Defect"
CAUSES OF ASD
• Congenital (From Birth) → Failure of normal septum
formation.
• Genetic Syndromes → Down Syndrome (Common in Ostium
Primum ASD).
Mnemonic: "ASD = Atrial Septum Defect"
SYMPTOMS OF ASD
• Small ASD (No Symptoms, Found by Chance)
• Large ASD (Symptoms Appear in Later Life)
- Shortness of breath (Dyspnea) on
exertion
- Frequent chest infections in children
- Palpitations (Atrial Fibrillation in
Adults)
- Heart Failure (Late stage due to
pulmonary hypertension)
Mnemonic: "ASD = Asymptomatic or Slow Dyspnea"
HEART SOUNDS IN
ASD
Wide Fixed Split of S2 → Due to delayed right
ventricular emptying.
Systolic Ejection Murmur (Pulmonary Valve Area) → Due
to increased blood flow.
Diastolic Flow Murmur (Tricuspid Area) → Due to
excessive right atrial filling.
Mnemonic: "A.S.D. Murmurs"
- Atrial
Murmur (Systolic over Pulmonary Valve)
- Splitting of
S2 (Wide & Fixed)
- Diastolic
Murmur (Tricuspid Valve)
COMPLICATIONS OF
ASD
• Heart Failure (Late)
• Pulmonary Hypertension
• Eisenmenger’s Syndrome (Shunt Reversal → Cyanosis & Clubbing)
• Atrial Fibrillation & Stroke (Due to blood clots)
Mnemonic: "H-P-E-A" (Complications of ASD)
- Heart
Failure
- Pulmonary Hypertension
- Eisenmenger’s
Syndrome
- Arrhythmia
(Atrial Fibrillation)
DIAGNOSIS OF ASD
ECG → Right Bundle Branch Block (RBBB), Left
Axis Deviation (Primum ASD)
Chest X-ray → Large Pulmonary Arteries,
Enlarged Right Heart
Echocardiography (ECHO – Best Test!) → Confirms size
& location of ASD
Doppler Color Flow Imaging → Detects
Left-to-Right Shunt
Mnemonic: "ECHO-X" (Tests for ASD)
- ECHO → Best
Test
- Chest X-ray
→ Heart & Lung Findings
- Holter
Monitor → If Arrhythmia is Suspected
- Oxygen Check
(Pulse Oximetry)
TREATMENT OF ASD
1. SMALL ASD
No treatment needed! (Most close by age 2-5 years)
2. LARGE ASD
(With Symptoms)
Medications:
- Diuretics (Furosemide)
→ Reduce extra fluid
- Beta-Blockers (If Arrhythmias)
Surgical Closure (If Pulmonary Flow >1.5:1)
- Percutaneous Device Closure (For
Secundum ASD)
- Open-heart Surgery (For Primum ASD or
Large Defects)
Mnemonic: "DOP" (Drugs for ASD)
- Diuretics
- Oxygen if
Needed
- Percutaneous/Surgical
Closure
CONTRAINDICATIONS
FOR ASD SURGERY
- Eisenmenger’s Syndrome (Irreversible Pulmonary Hypertension)
- Severe Right Heart Failure
Mnemonic: "Eisenmenger = End of Surgery"
PROGNOSIS OF ASD
- Small ASD → Excellent (May close on its own)
- Large ASD → Good if Treated Early
- Untreated Large ASD → Heart Failure & Stroke Risk
Mnemonic: "ASD = Asymptomatic or Slow Dyspnea"
FINAL REVISION WITH MNEMONICS
- ASD = "Atria’s Septal Defect"
- Symptoms = "ASD = Asymptomatic or Slow Dyspnea"
- Heart Sounds = "A.S.D. Murmurs" (Atrial Murmur, S2 Split, Diastolic Flow Murmur)
- Complications = "H-P-E-A" (Heart Failure, Pulmonary HTN, Eisenmenger, Arrhythmia)
- Diagnosis = "ECHO-X" (ECHO, X-ray, Holter, Oxygen Check)
- Treatment = "DOP" (Diuretics, Oxygen, Percutaneous Closure)
- Surgery Contraindicated in Eisenmenger's (Mnemonic: "Eisenmenger = End of Surgery")
