Which is the most common congenital cardiac abnormality?
Congenital bicuspid aortic valve.
What are the common causes of aortic stenosis (AS)?
Congenital bicuspid aortic valve, rheumatic fever, and, in adults of advanced age, idiopathic degenerative sclerosis with calcific AS.
What are the anatomical types of aortic stenosis?
- Valvar- commonly due to bicuspid aortic valve
- Supravalvular- caused by discrete membrane or constriction
- Subvalvular- caused by a congenital membrane or fibrous ring
What syndrome is associated with supravalvular aortic stenosis?
Williams syndrome- characterized by idiopathic hypercalcemia of infancy, characteristic facial appearance, mild to moderate intellectual disability, unique personality characteristics, and supravalvular aortic stenosis.
What congenital heart defects may be associated with valvular aortic stenosis?
Patent ductus arteriosus, coarctation of aorta, and ventricular septal defects. Bicuspid aortic valve is associated with dilation of ascending aorta.
What are the symptoms of aortic stenosis?
Infants:
Signs of congestive heart failure:
Pale, mottled Hypotensive Dyspneic
Auscultatory findings of AS:
Ejection click Gallop rhythm
Ejection systolic murmur along the mid-left and right upper sternal borders, radiating to the carotid arteries
Signs of progressive shock and tissue hypoperfusion:
Hypoxia (PaO2 30-40 mmHg)Metabolic acidosis
Older children and adolescents
Usually, asymptomatic Classic triad (in 10%) is syncope, angina, and exertional dyspnea
May develop symptoms of Heart failure or Arrhythmias
What is the examination finding in aortic stenosis?
Palpation:
Peripheral pulses- reduced in amplitude and slow rising (pulsus parvus et tardus)Unequal systolic blood pressure in the upper extremities (right > left), in supravalvar ASApical impulse- sustainedPalpable 4th heart sound (S4), felt best at the apexPrecordial Systolic thrill, felt best at the left upper sternal border
Auscultation:
Narrowly split, single, or a paradoxically split S2Fourth heart sound may be audible Ejection click (unaffected by respiration)Low-pitched crescendo–decrescendo ejection systolic murmur, at the right and left upper sternal border, radiating to the carotid arteries. The murmur increases in intensity by maneuvers that increase stroke volume, such as isotonic exercise and premature ventricular contractions.
What are the ECG findings in AS?
Left ventricular hypertrophy with strain pattern (ST depression and inverted T wave) with ST-segment depression of 2 mm or more in the left precordial leads, left-axis-deviation, arrhythmias.
What are the Chest XRay findings in AS?
Heart size may be normal or slightly enlarged. Ascending aorta may be dilated.
What is the treatment of aortic stenosis?
Therapeutic intervention options:
Percutaneous balloon aortic valvotomySurgical aortic valvotomy
Ross procedure (replacement of aortic valve with patient’s own pulmonic valve)
In Older children and Adults: Aortic Valve replacement (Surgical AVR, with mechanical or bioprosthetic valve, or Transcatheter percutaneous aortic valve implantation i.e. TAVI)
Immediate treatment of Neonates with critical Valvar aortic stenosis:
If ductus-dependent systemic circulation, the neonate will present with rapidly progressive congestive heart failure as the PDA closes.
This requires urgent prostaglandin E1 infusion, inotropic support, diuretics, correction of metabolic acidosis, and mechanical ventilation to improve the systemic perfusion, followed by balloon valvotomy.
Asymptomatic AS in adults
Asymptomatic AS in adults usually requires no treatment.
Symptomatic AS in older children and adults:
Indication of intervention: Severe, high-gradient aortic stenosis (mean gradient >40 mmHg or peak velocity >4.0 m/s), or in severe low-gradient (<40 mmHg) aortic stenosis with low ejection fraction (EF <50%) and low flow.
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