Congenital Heart Defects and Arrhythmias Clinical Summary

Posted on Dec 7, 2025 in Agriculture

Aortic Stenosis

Genetics (Gx)

• Narrowing of the Aortic (Bicuspid Valve).
• Most common cause of aortic valve pathology obstruction.

Pathophysiology (Px)

• Left Ventricle (LV) must pump harder to override the blockage, leading to LV hypertrophy.

Clinical Findings (CF)

1. A systolic murmur in the right precordium can be heard (right, not left), above the 2nd intercostal space (IC).
2. Late findings: dizziness, syncope, exercise intolerance.
3. Suprasternal notch: A systolic thrill may be felt.
4. In severe cases, can lead to hypoperfusion (weak peripheral pulse, pale appearance, renal failure [RF]).

Diagnosis (DX)

1. ECG: Shows LVH.
2. X-ray: Heart size normal or dilated LV; dilated ascending aorta.
3. US (Diagnostic): Helps find the cause and assess valve function.

Treatment (Tx)

• Surgery:
  • In case of supravalvar aortic stenosis (pressure between aorta and LV 60–80 mmHg): Membrane is resected.
  • In case of valvar aortic stenosis: Balloon valvoplasty.

Atrial Septal Defect (ASD)

Genetics (Gx)

• Hole between the Right Atrium (RA) and Left Atrium (LA).
• Less severe than Ventricular Septal Defect (VSD) because the pressure in the atria is not as high, and the pressure difference is not as great (around 4 mmHg).
• History of frequent colds and productive cough due to slightly increased pressure in the pulmonary artery, which can cause slight pulmonary edema.
• This puts patients at risk of getting viral infections.

Symptoms (Sx)

• Systolic murmur (heard at the left upper sternal border, 2nd–3rd IC space).
• Fixed S2 split sound.

Diagnosis (Dx)

1. Best initial test is ECG: To also rule out the presence of subclinical atrial stenosis; shows partial Right Bundle Branch Block (RBBB) indicating Right Ventricular Hypertrophy (RVH).
2. X-ray: Increased transverse diameter with pulmonary plethora.
3. US: Is diagnostic.

Treatment (Tx)

• No necessity (NECC) needed; treatment is based on the presence of symptoms and patient wishes.
• Surgical closure can be done percutaneously or openly.

Tetralogy of Fallot (TOF)

Genetics (Gx)

• Cyanotic heart defect.
• Components: VSD + Overriding Aorta.
• Outcome results in Pulmonary Stenosis + Pulmonary Hypertension (HBP) + RVH.
• Most common cyanotic Congenital Heart Defect (CHD).

Presentation (Px) (READ)

It is basically 4 problems caused by the initial 2 problems. Sum up:

1. Overriding Aorta (Aorta very close to the septum).
2. Pulmonary Stenosis (Valves are very thick and closed).
3. RVH.
4. VSD.

Clinical Findings (CF)

1. Acutely cyanotic, often relieved by squatting.
2. Associated with Chromosome 22 gene deletion.
3. Chronic cyanosis (finger clubbing).
4. Low height percentile.
5. Systolic murmur.
6. Loud S2.
7. Hypoxic spell (Episodes of severe cyanosis with finger clubbing and possible growth retardation).

Diagnosis (Dx)

1. ECG: RVH.
2. US (Echocardiogram) is best; will probably show RVH.
3. X-ray: Cardiomegaly / Hypovolemia.

Treatment (Tx)

• Surgical repair (Not emergent but must be done):
  • Palliative surgery if severe hypoxia.
  • Radical repair at 1 year of life.

Complications

1. Cerebral thrombosis.
2. Iron deficiency (Fe Deficit).
3. Cerebral abscess.
4. Infective endocarditis.

Infective Endocarditis (IE) Prophylaxis

High-Risk Conditions (L)

1. Dental procedures.
2. Invasive respiratory procedures.
3. Prosthetic cardiac valves/material.
4. History of infective endocarditis.
5. CHD: (Cyanotic heart defects without surgery) or (CHD repaired with prosthetic material) or (Defect remains at the site or adjacent to the site).
6. Defect corrected with prosthetic material 6 months from operation.
7. After implant (prosthetic/device).

Antibiotics Used (Ax Used)

• Dental: IV Amoxicillin 50 mg/Kg 30–60 min prior.
• Invasive Procedure: Oxacillin & Cephalosporin.
• GI Tract & Urinary Procedure: Ampicillin, Amoxicillin, Vancomycin.
• Surgeries: Oxacillin or Cephalosporin.

Patent Ductus Arteriosus (PDA)

Genetics (Gx)

• Non-cyanotic defect.
• Ductus Arteriosus (DA) fails to close (should close during infancy).
• Failure to close results in shunting (LV to RV shunt).
• Blood moves from the Aorta to the Pulmonary Trunk, moving oxygenated blood into the pulmonary circulation.

Clinical Data (CD)

1. Many are asymptomatic (depend on size).
2. Loud, constant “machine-like” murmur heard in the upper left sternal border during systole and diastole.
3. S2 is hard to hear.

Diagnosis (Dx)

1. ECG: LVH.
2. X-ray: Normal heart size or cardiomegaly (sometimes).
3. US (Echocardiogram): Diagnostic.

Complication

• Pulmonary HBP.
• Infective Endocarditis.

Treatment (Tx)

• A: No sign of congestive Heart Failure (HF) / Premature: Give Indomethacin.
• B: Sign of Congestive HF / Not premature: Surgical Closure.

Note: X-ray and US are important.

Ventricular Septal Defect (VSD)

Genetics (Gx)

• Congenital, non-cyanotic heart defect.
• The wall between the LV and RV is incompletely closed.
• More dangerous than ASD because the pressure in the ventricles is much higher (the difference is 116 mmHg—very big).
• Typically presents in infants with failure to thrive (due to hypoxia).

Symptoms (Sx)

1. Systolic murmur + thrill (heard best around the left upper sternal border).
2. Tachypnea.
3. Sweating.

Diagnosis (Dx)

1. ECG: Biventricular Hypertrophy!
2. Chest X-ray: Cardiomegaly.
3. US (DX): Best initial test.

Treatment (Tx)

• 50% close spontaneously.
• Surgical closure if Qp:Qs > 2:1.

Indication for Surgery

• Small defect with no symptoms = No danger.
• VSD > 50% Diameter of Aorta + HF not corrected by medication.

Operation before 1 Year:

1. VSD > 50% of the diameter of the aorta.
2. Pressure in the Pulmonary Artery > 50 mm Hg.
3. HF is not corrected by medication (X).

Supraventricular Tachycardia (SVT)

Genetics (Gx)

Arrhythmia originating from the ventricles (Note: SVT originates above the ventricles, this section seems to mix concepts).

Types

Atrial Fibrillation, Atrial Flutter, Wolff-Parkinson-White Syndrome.

Symptoms (Sx)

Palpitations, Anxiety, Chest pain.

Diagnosis (Dx)

ECG.

Treatment (TX) for SVT

1. Conversion Therapy is Adenosine IV.
2. Vagal Maneuvers are effective.
3. For maintenance treatment: Propafenone/Amiodarone/Intracardiac ablation (Intracardiac1).

Ventricular Tachycardia (VT)

Risk Factors (RF)

MI (Myocardial Infarction), Long QT syndrome, Ventricular Hypertrophy.

Symptoms (Sx)

Palpitation, Cardiac arrest, HF (Shortness of breath/syncope).

Causes of Ventricular Tachycardia in Children (VT)

Myocarditis, Cardiomyopathy, Ventricular Tumors, CHD.

Treatment (Tx)

I-Many VTs are not a cause for worry.

II-The ones to worry about are those causing Hypotension/syncope/Cardiac arrest!

• A- If Central Pulse is Palpable: Synchronized Cardioversion or give Amiodarone.
• B- If Central Pulse is Not Palpable: Treat as V Fib (Defibrillation, Epinephrine [NE], Resuscitation).

Coarctation of the Aorta (Narrowing of Aorta)

Genetics (Gx)

• Congenital narrowing of the Aorta (usually descending).
• 14% of CHD; more common in boys.
• Associated with: Bicuspid aortic valves, VSD, PDA.
• Risk: Cardiac Failure (2–3 weeks old) + Arterial HBP.

Clinical Findings (CF)

I-Early:

• Tachycardia/Tachypnea/Shock.
• Femoral pulse is absent.
• Systolic murmur not heard or heard between the shoulders.

II-Late:

• Hypertension.
• Murmur.

Diagnosis (Dx)

• ECG: Shows LVH.
• X-ray: Cardiomegaly + Pulmonary congestion (Dilatation of Left Ventricle!, Dilated Ascending Aorta).
• Echo (US): Diagnostic (Narrowing of aorta, change in blood flow pattern at the site).

Treatment (Tx)

• Surgery:
  • For infants: Aorta is operated on in the first few months of life.
  • For adult type: At 3–10 years of life.
• Without surgery, life expectancy is 30–40 years.
• Planned surgery: 3–10 years.

Complication in No Surgery (L)

Coarctation of the Aorta: LVH (ECG) + MRI.

Hypertension (HBP)

Indication and Assessment of BP Measurement in Children:

Usually, we start routinely measuring at age 3. But in some cases, we need to measure before 3 years:

1. Prematurity, Low Birth Weight.
2. CHD.
3. Urinary Tract Infection (UTI).
4. Kidney disease (History).
5. Organ transplant.
6. Malignant process.
7. Sign of increased Intracranial pressure.

Essential Hypertension:

Genetics (Gx)

• Child DBP/SBP > 95th percentile on 3 occasions.
• “The smaller the child & the higher the BP, the more likely it is to be secondary.”
• If secondary, symptoms/damage to organs/DM without treatment.
• Treatment (TX): Calcium Channel Blockers.