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persistent ostium primum (partial atrioventricular canal)
Pathology:
1) congenital opening in septum near AV valves
2) cleft mitral valve leaflet common
3) left atrial enlargement may occur secondary to mitral regurgitation
4) associated anomalies
a) mitral & tricuspid valve anomalies
b) ventricular septal defect
Clinical manifestations:
1) dyspnea
2) round chest, precordial bulge rare
3) no cyanosis or clubbing of fingers
4) accentuated precordial apical thrust
- volume overload
- elevated central venous pressure
- right ventricular lift
5) accentuated P2 with fixed splitting during inspiration & expiration
6) systolic thrill near sternal border
7) harsh systolic murmur (mitral regurgitation)
a) at left sternal border
b) transmitted to maxilla
8) occasional apical mid diastolic murmur
Special laboratory:
- electrocardiogram:
a) left axis deviation*
b) late R' in right-sided leads
c) 1st degree AV block (75%)
d) left atrial enlargement may be present
* distinguishing feature from persistent ostium secundum
Radiology:
1) enlarged ventricles, left & right
2) enlarged pulmonary arteries
- increased pulmonaru vascularity
3) left atrial enlargement may be present
Complications:
- right ventricular hypertrophy
- right atrial enlargement
- atrial fibrillation
- mitral regurgitation (from mitral valve cleft)
- pulmonary hypertension (rare)
General
congenital heart disease; congenital cyanotic heart disease
atrial septal defect (ASD)
References
- DeGowin & DeGowin's Diagnostic Examination, 6th edition,
RL DeGowin (ed), McGraw Hill, NY 1994, pg 868
- Mayo Internal Medicine Board Review, 1998-99, Prakash UBS (ed)
Lippincott-Raven, Philadelphia, 1998, pg 45-46
- Medical Knowledge Self Assessment Program (MKSAP) 11, 16, 17, 18.
American College of Physicians, Philadelphia 1998, 2012, 2015, 2018