Acyanotic CHDs Overview - No Blue Babies!
- No initial cyanosis; blood shunts Left → Right or faces outflow obstruction.
- Classification & Presentation:
- Left-to-Right (L-R) Shunts: ↑ Pulmonary blood flow (PBF).
- Examples: Ventricular Septal Defect (VSD), Atrial Septal Defect (ASD), Patent Ductus Arteriosus (PDA).
- Symptoms: Murmur, recurrent respiratory infections, failure to thrive (FTT), signs of Congestive Heart Failure (CHF).
- Obstructive Lesions: No shunt; restricted ventricular outflow.
- Examples: Aortic Stenosis (AS), Pulmonary Stenosis (PS), Coarctation of Aorta (CoA).
- Symptoms: Murmur, exercise intolerance, syncope (AS), differential BP (CoA).
- Left-to-Right (L-R) Shunts: ↑ Pulmonary blood flow (PBF).
⭐ Most common congenital heart disease overall, Ventricular Septal Defect (VSD), is acyanotic and an L-R shunt lesion.
VSD & ASD - Septal Shunt Stories
| Feature | Ventricular Septal Defect (VSD) | Atrial Septal Defect (ASD) |
|---|---|---|
| Epidemiology | Most common CHD | Common CHD; F>M |
| Types | Perimembranous (most common), muscular, inlet, supracristal | Ostium secundum (most common), primum, sinus venosus |
| Murmur | Harsh pansystolic, LLSB; thrill | Ejection systolic, ULSB; 📌 Fixed wide split S2 |
| ECG | LVH (mod VSD), BVH (large VSD) | RAD, rsR' in V1 (RV vol overload); Crochetage (primum) |
| CXR | Cardiomegaly, ↑ pulmonary vascular markings | Cardiomegaly (RA, RV enlarge), ↑ pulmonary vascular markings |
| Complications | Eisenmenger syndrome, IE, AR | Pulmonary HTN, paradoxical embolism, arrhythmias (AF) |
| Management Highlights | Spontaneous closure (muscular); Surgery if $Qp/Qs$ > 1.5-2:1 | Device/Surgery if $Qp/Qs$ > 1.5:1; Often asymptomatic |
PDA & Coarctation - Duct & Constriction Dramas
Patent Ductus Arteriosus (PDA) and Coarctation of Aorta (CoA) represent significant acyanotic congenital heart diseases, one a persistent duct, the other a critical aortic narrowing.
| Feature | PDA (Patent Ductus Arteriosus) | Coarctation of Aorta (CoA) |
|---|---|---|
| Pathophys. | Aorta-PA shunt (L→R) | Aortic narrowing (juxtaductal) |
| Murmur | 📌 Continuous "machinery" (Gibson) L infraclavicular | Systolic (L interscapular); possible ejection click |
| Pulses | Bounding; Wide pulse pressure | Radio-femoral delay; BP: Upper > Lower limbs (> 20 mmHg) |
| CXR | Cardiomegaly, ↑ pulm. vascularity | "3" sign; 📌 Rib notching (Roesler's sign, collaterals) |
| Rx | Preterm: Indomethacin/Ibuprofen; Device/Surgical closure | Neonates: PGE1; Surgical/Balloon angioplasty |
 |
PDA Management Algorithm:
⭐ Indomethacin or Ibuprofen promotes PDA closure in preterms. Prostaglandin E1 (PGE1) keeps the ductus arteriosus open, vital in duct-dependent lesions like severe CoA.
Valvular Stenoses (AS & PS) - Outlet Obstruction Ops
| Feature | Aortic Stenosis (AS) | Pulmonary Stenosis (PS) |
|---|---|---|
| Types | Valvular, Subvalvular (membranous/muscular), Supravalvular | Valvular (most common), Subvalvular (infundibular), Supravalvular |
| Murmur | Ejection systolic @ RUSB, radiates to carotids; ↑squatting | Ejection systolic @ LUSB, radiates to back/axilla; ↑inspiration |
| Symptoms | 📌 SAD: Syncope, Angina, Dyspnea; CHF (infants) | Often asymptomatic; Dyspnea, fatigue; RV failure (severe) |
| ECG | LVH (strain pattern) | RVH (strain pattern) |
| Echo | Thickened valve, ↓mobility, LVH; Post-stenotic aortic dilatation | Thickened valve, doming, RVH; Post-stenotic PA dilatation |
| Severity (Peak Gradient mmHg) | Mild: <25; Mod: 25-49; Severe: ≥50 | Mild: <30; Mod: 30-60; Severe: >60 |
| Management | Balloon valvuloplasty (children), Valve replacement; PGE1 (critical AS) | Balloon valvuloplasty (preferred), Surgical valvotomy |
High‑Yield Points - ⚡ Biggest Takeaways
- VSD: Most common CHD overall; presents with harsh holosystolic murmur at left lower sternal border.
- ASD: Characterized by wide, fixed split S2; carries risk of paradoxical emboli in adults.
- PDA: Features continuous machine-like murmur; indomethacin for closure, prostaglandins maintain patency.
- Coarctation of Aorta: Shows BP discrepancy (↑upper, ↓lower limbs), weak femoral pulses, and rib notching.
- Syndromic associations: Down syndrome (AVSDs, VSD), Turner syndrome (coarctation, bicuspid aortic valve).
- All left-to-right shunts can eventually lead to pulmonary hypertension and Eisenmenger syndrome (cyanosis).
Unlock the full lesson and continue reading
Signup to continue reading this lesson and unlimited access questions, flashcards, AI notes, and more
