Ref: Harrison's Principles of Internal Medicine, 18ed. & Nelson Texbook of Pediatrics, 19th ed.Explanation:Intermittent vascular claudication most often refers to cramping pains in the buttock or leg muscles. It is caused by poor circulation of the blood to the affected area. The poor blood flow is often a result of atherosclerotic blockages more proximal to the affected area.Chronic Atherosclerotic Occlusive DiseaseAtherosclerosis may affect the thoracic and abdominal aorta.Occlusive aortic disease caused by atherosclerosis usually is confined to the distal abdominal aorta below the renal arteries.Frequently the disease extends to the iliac arteriesClaudication characteristically involves the buttocks, thighs, and calves and may be associated with impotence in males (Leriche syndrome).The severity of the symptoms depends on the adequacy of collaterals. With sufficient collateral blood flow, a complete occlusion of the abdominal aorta may occur without the development of ischemic symptoms.The physical findings include the absence of femoral and other distal pulses bilaterally and the detection of an audible bruit over the abdomen (usually at or below the umbilicus) and the common femoral arteries.Atrophic skin, loss of hair, and coolness of the lower extremities usually are observed.In advanced ischemia, rubor on dependency and pallor on elevation can be seen.Clinical Manifestations of Coarctation of the aortaIt is not usually associated with significant symptoms.Weakness or pain (or both) in the legs after exerciseHypertension on routine physical examination.Disparity in pulsation and blood pressure in the arms and legs (The classic sign of CO A)The femoral, popliteal, posterior tibial, and dorsalis pedis pulses are weak tor absent in up to 40% of patients), in contrast to the hounding pulses of the arms and carotid vessels.The radial and femoral pulses should always be palpated simultaneously for the presence of a radial-femoral delay.Normally, the femoral pulse occurs slightly before the radial pulse.A radial-femoral delay occurs when blood flow to the descending aorta is dependent on collaterals, in which case the femoral pulse is felt after the radial pulse.In normal persons (except neonates), systolic blood pressure in the legs obtained by the cuff method is 10-20 mm Hg higher than that in the arms.In coarctation of the aorta, blood pressure in the legs is lower than that in the armsThis differential in blood pressures is common in patients with coarctation who are older than 1 yrIt is important to determine the blood pressure in each armRight arm BP > Left arm BP: Left subclavian artery is involved in the area of coarctation.Left arm BP > Right arm BP: Right subclavian arises anomalously from below the area of coarctationWith exercise, a more prominent rise in systemic blood pressure occurs, and the upper-to-lower extremity pressure gradient will increase.The precordial impulse and heart sounds are usually normal.The presence of a systolic ejection click or thrill in the suprasternal notch suggests a bicuspid aortic valve (present in 70% of cases).A short systolic murmur is heard along the left sternal border at 3-4 ICS.In older patients with well-developed collateral blood flow, systolic or continuous murmurs maybe heard over the left and right sides of the chest laterally and posteriorly (SUZMAN's sign)A palpable thrill in the intercostal spaces on the back may be seen