Examination and Investigations of CYANOTIC CONGENITAL HEART DISEASE

      Collateral circulation / anastomoses in coarcta­tion of aorta       Examination of precordium :

• A systolic thrill may be felt in the suprasternal notch.
• There is a heaving left ventricular apical impulse due to pressure over­load of LV.
• A systolic murmur may be heard at the right upper
• Prominent pulsations may be felt in the intercostal areas.
• Sl and S2 are normal.
• ernal border and between the scapulae.

coarcta­tion of aorta Physical Exam

• Cyanosis, rarely
• In infancy, also may have heart failure, failure to thrive, irritability, tachypnea, and dyspnea
• HTN
• Pulse disparity: Pulse delay in femoral vs radial artery and increased amplitude in brachial vs femoral pulse
• Prominent neck pulsations
• Epistaxis
• Delayed, weak, or absent lower extremity pulse
• Prominent left ventricular impulse
• 10 mmHg compared with lower extremity.
• Bruit (coarctation, collaterals, patent ductus arteriosus)
• Murmur (aortic stenosis or insufficiency, ventricular septal defect, rarely mitral valve)
• S₄systolic ejection click
• BP: Evaluation shows upper limb systemic HTN and a differential
• Funduscopy: Corkscrew tortuosity of retinal arterioles
• Extensive collaterals develop from branches of the subclavian, internal mammary, superior intercostal, and axillary arteries.
• Left arm diameter may be smaller than the right.

Collateral circulation / anastomoses in coarcta­tion of aorta

• · Internal mammary artery and deep inferior epi­gastric artery, branch of external iliac artery.
• · Lateral thoracic branch of axillary artery with
• · The transverse cervical artery, a branch of sub­clavian artery communicates with posterior in­tercostal arteries.
• · Anterior intercostal branches of internal mam­mary artery and posterior intercostals, branches of descending aorta.
• posterior intercostal arteries.
• There is notching of the ribs seen on X-ray due to these anastomoses, in the 3rd to 9th ribs.
• The 10th to 12th aortic intercostal arteries do not anastomose with internal mammary arteries so notch­ing is absent in 10th to 12th rib.
• The first 2 or 3 intercostal spaces are supplied by supreme intercostal artery posteriorly which is a branch of subclavian artery. Therefore, there is no notching of the upper three ribs.

Complications of coarcta­tion of aorta

• · Left ventricular failure
• · Infective endocarditis
• · Aortic rupture
• · Dissecting aneurysm

Investigations Findings —

• Doppler exam of pulses reveals disparity.
• Transesophageal echocardiography
• Echocardiography for coexisting cardiac anomalies
• MRA/MRI

X–ray:  

• dilated left subclavian artery may be seen as a prominence in the left superior mediastinum.
• CXR may show rib notching, “3” sign, rarely cardiomegaly.
• A barium study of esophagus shows reverse 3 sign which is due to indentations on the left side of the barium-filled oesophagus. The upper one is caused by pre-stenotic dilatation of aorta and lower one by post-stenotic dilatation of aorta.
• There is notching of the ribs seen on X-ray due to anastomoses, in the 3rd to 9th ribs, on the lower borders.

ECG

• ECG may show right ventricular hypertrophy in neonates but left ventricular hypertrophy in older patients.
• Shows left ventricular hypertrophy, Left axis devia­tion (LAD), left bundle branch block, sometimes right ventricular hypertrophy.

2D echocardiogram

• Shows the interrupted arch, LVH, dilated ascending aorta and arch.

Doppler study

• Localises the site of the coarct and measures the gra­dient.