B. Polyarteritis Nodosa - Is a systemic vasculitis of small- or medium-sized muscular arteries. - Typically involving renal and visceral vessels but sparing the pulmonary circulation. - Vessels of the kidneys, heart, liver, and gastrointestinal tract are involved in descending order of frequency.

- Impaired perfusion with ulcerations, infarcts, ischemic atrophy, or hemorrhages may be the first sign of disease - A “classic” presentation can involve some combination of a. Rapidly accelerating hypertension due to renal artery involvement; b. Abdominal pain and bloody stools caused by vascular gastrointestinal lesions;

- Renal involvement is often prominent and a major cause of mortality. - Untreated, PAN is typically fatal; however, immunosuppression can yield remissions or cures in 90% of cases.

Kawasaki Disease -Kawasaki disease is an acute febrile, usually self-limited illness of infancy and childhood (80% of patients are 4 years old or younger); - Its clinical significance stems primarily from a predilection for coronary artery involvement that

can cause aneurysms that rupture or thrombose, resulting in acute myocardial infarctions. - Is is the leading cause of acquired heart disease in children.

Clinical Features. - Kawasaki disease typically presents with conjunctival and oral erythema and blistering, edema of the hands and feet, erythema of the palms and soles, a desquamative rash, and cervical lymph node enlargement (hence its other name, mucocutaneous lymph node syndrome).

- Approximately 20% of untreated patients develop cardiovascular sequelae, ranging from asymptomatic coronary arteritis, to coronary artery ectasia, to giant coronary artery aneurysms (7 to 8 mm) leading to rupture or thrombosis, myocardial infarction, and sudden death.

Microscopic Polyangiitis - Microscopic polyangiitis is a necrotizing vasculitis that generally affects capillaries, small arterioles and venules. - Depending on the vascular bed involved, major clinical features include

hemoptysis, hematuria and proteinuria, bowel pain or bleeding, muscle pain or weakness, and palpable cutaneous purpura

1.recurrent oral aphthous ulcers, 2.genital ulcers, 3. and uveitis. Behçet Disease - Behçet disease is a small- to medium-vessel neutrophilic vasculitis that classically presents as a clinical triad of 1.recurrent oral aphthous ulcers, 2.genital ulcers, 3. and uveitis.

4.Granulomatosis with Polyangiitis :Previously called Wegener granulomatosis, - Is characterized by a triad of: 1. Necrotizing granulomas of the upper respiratory tract (ear, nose, sinuses, throat) or the lower respiratory tract (lung) or both.

2. Necrotizing or granulomatous vasculitis affecting capillaries, venules, arterioles, and arteries) most prominent in the lungs and upper airways 3.Focal necrotizing, often crescentic, glomerulonephritis

- Classic features include Clinical Features. - Classic features include 1.persistent pneumonitis with bilateral nodular and cavitary infiltrates (95%), 2.chronic sinusitis (90%), 3. evidence of renal disease (80%).

Thromboangiitis Obliterans (Buerger Disease) - Is characterized by: 1. Segmental, thrombosing, acute and chronic inflammation of medium-sized and small arteries, principally the tibial and radial arteries, with occasional secondary extension into the veins and nerves of the extremities.

2. It is a distinctive disease that often leads to vascular insufficiency, typically of the extremities. 3. It occurs almost exclusively in heavy cigarette smokers, usually before age 35.

Clinical Features. 1. Leg pain induced by exercise that is relieved on rest (intermittent claudication), 2. instep foot pain induced by exercise (instep claudication), 3. and a superficial nodular phlebitis (venous inflammation).

- The vascular insufficiency of Buerger disease tends to be accompanied by severe pain—even at rest—due to the neural involvement. - Chronic extremity ulcerations develop, progressing over time (occasionally precipitously) to frank gangrene.

- Smoking abstinence in the early stages of the disease can often ameliorate further attacks; however, once established, the vascular lesions typically do not respond to smoking abstinence.

Ischemic heart disease

Ischemic Heart Disease Ischemic heart disease (IHD) represents a group of pathophysiologically related syndromes resulting from myocardial ischemia—an imbalance between myocardial supply (perfusion) and cardiac demand for oxygenated blood.

Angina Pectoris - Angina pectoris is characterized by paroxysmal and usually recurrent attacks of substernal or precordial chest discomfort caused by transient (15 seconds to 15 minutes) myocardial ischemia that is insufficient to induce myocyte necrosis.

1-stable angina (occur after certain levels of exertion) and caused by - is episodic chest pain associated with exertion or some other form of increased myocardial oxygen demand (e.g., tachycardia or hypertension due to fever, anxiety, fear).

- pain a crushing or squeezing substernal sensation, - radiate down the left arm or to the left jaw (referred pain). -lesion obstructing 70% to 75% or more of a vessel lumen = critical stenosis → cause angina only in the setting of increased demand

The pain is relieved by rest (reducing demand) or by administering agents such as nitroglycerin; such drugs cause peripheral vasodilation and thus reduce venous blood delivered to the heart → reducing cardiac work. - in larger doses, nitroglycerin also increases blood supply to the myocardium by direct coronary vasodilation

2-variant angina or Prinzmetal angina ( due to vessel spasm ) completely normal vessels can be affected. Treatment: administration of vasodilators such as nitroglycerin or calcium channel blockers.