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Common Congenital Heart Lesions - page 3 / 126





3 / 126

3 of 126

Acyanotic 1. Atrial Septal Defect

Clinical Presentation: Usually asymptomatic and detected by murmur, may have dyspnea on exertion, fatigue, or recurrent lower resp. tract infections; also decreased stamina and palpitations (from atrial arrhythmias 2° to RA enlargement)

Physical Findings:

  • 1.

    prominent systolic impulse along left sternal border (RV heave) (dilated RV)

  • 2.

    wide, fixed splitting of S2 (decreased ejection time)

  • 3.

    systolic murmur over pulmonary valve (increased volume over Pulm valve)

  • 4.

    mid-diastolic murmur over left lower sternal border/ tricuspid valve

(increased flow over tricuspid valve) **Blood going through ASD does NOT cause a murmur

Diagnostic Imaging and Testing:

  • A.

    Chest radiograph: dilated RA and RV, prominent PA, increased pulm markings

  • B.

    ECG: RVH, RA enlargement, RBBB, Left axis deviation for ostium primum type ASD

  • C.

    Echo: RA and RV enlargement, ASD visualized or determined using Doppler

  • D.

    Cardiac cath: only to determine pulm. vascular resistance, shows increased O2 in RA

Treatment: surgical repair only if large volume through shunt

Etiology: persistent opening in atrial septum allowing direct communication between left and right atria. Three types (most to least common):

  • 1.

    Ostium Secundum ASD: lesion near foramen ovale, caused by increased reabsorption of septum primum or inadequate formation in septum secundum

  • 2.

    Ostium Primum ASD: lesion near bottom of atrial septum, caused by failure of septum primum to fuse with endocardial cushions, assoc. w/ abnormal development of AV valves

  • 3.

    Sinus Venosus ASD: lesion at top of atrial septum, caused by incomplete absorption of sinus venosus into RA, assoc. w/ drainage of pulm veins into RA

  • 4.

    Patent foramen ovale: NOT ASD, 20% of the population has it, and it’s no big deal unless have 1.) increased pulmonary pressure resulting in right to left shunt 2.) paradoxical embolism

Pathology: gross specimen has a hole in the atrial septum; enlarged RA and RV

Pathophysiology: Flow through defect depends on its size and the compliance of the ventricles. If uncomplicated, blood goes from LA to RA, causing volume overload and enlargement of RA and RV. Can lead to Eisenmenger syndrome. Epidemiology: common (1/1500 live births)

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