高血压英文ppt精品课件systemic

SYSTEMIC HYPERTENSION RANDA M. AL-HARIZY Prof. of Internal Medicine SYSTEMIC HYPERTENSION Definitions of hypertension Elevated arterial blood pressure is a major cause of premature vascular disease leading to cerebrovascular events, ischaemic heart disease and peripheral vascular disease. Hypertension - Introduction l Silent Killer painless complications l It is the leading risk factor MI, HF, CRF Stroke l Responsible for the majority of office visits, l Number one reason for drug prescription. l 25% of population l Complications bring to diagnosis but late Regulation of BP: BP = Cardiac Output x Peripheral Resistance l Endocrine Factors Renin, Angiotensin, ANP, ADH, Aldosterone. l Neural Factors Sympathetic & Parasympathetic l Blood Volume Sodium, Mineralocorticoids, ANP l Cardiac Factors Heart rate & Contractility. Control of Blood Pressure: BP Cardiac Output PeripheralResistance Blood Volume Na+, Aldosterone Vasoconstrictors Angiotensin II Catecholamines VasodilatorsPg & Kinins Local Factors pH, Hypoxia Neural Factors aAdrenergic Cons Adrenergic - Dil Cardiac Factors Rate & Contract Humoral Factors Etiology 1- Essential: In more than 95% of cases, an underlying cause cannot be found. Proposed mechanisms include: l Excess renal sodium retention l Over activity of sympathetic nervous system l Renin angiotensin excess l Hyperinsulinemia l Alterations in vascular endothelium Factors contributing to the development of Essential hypertension Genetic Factors: hypertension is more common in some families and in some ethnic groups like African Americans Environmental factors include obesity, alcohol, lack of exercise and excess salt intake 2- Secondary hypertension Renal: These account for over 80% of the cases of secondary hypertension. The common causes are diabetic nephropathy, chronic glomerulonephritis, adult polycystic disease, chronic tubulointerstitial nephritis, and renovascular disease. Endocrinal: These include Conns syndrome, adrenal hyperplasia, acromegaly, Phaeochromocytoma, Cushings syndrome. Drugs and toxins Pregnancy-induced hypertension Vascular: coarctation of aorta, vasculitis Complications l Cerebrovascular disease and coronary artery disease are the most common causes of death, although hypertensive patients are also prone to renal failure and peripheral vascular disease. HYPERTENSION Classification of blood pressure levels: (according to the British Hypertension Society) Category Systolic blood pressure Diastolic blood pressure Optimal 120 mmHg). l Unless treated, it may lead to death from progressive renal failure, heart failure, aortic dissection or stroke. l The changes in the renal circulation result in rapidly progressive renal failure, proteinuria and haematuria. There is also a high risk of cerebral oedema and haemorrhage with resultant encephalopathy, and in the retina there may be flame-shaped haemorrhages, cotton wool spots, hard exudates and papilloedema HISTORY l The patient with mild hypertension is usually asymptomatic. l Attacks of sweating, headaches and palpitations may point towards the diagnosis of phaeochromocytoma. l Higher levels of blood pressure may be associated with headaches, epistaxis or nocturia. l Breathlessness may be present owing to left ventricular hypertrophy or cardiac failure. l Malignant hypertension may present with severe headaches, visual disturbances, fits, transient loss of consciousness or symptoms of heart failure. EXAMINATION l Elevated blood pressure is usually the only abnormal sign. l Signs of an underlying cause should be sought, such as renal artery bruits in renovascular hypertension, or radiofemoral delay in coarctation of the aorta. l The cardiac examination may also reveal features of left ventricular hypertrophy and a loud aortic second sound. If cardiac failure develops, there may be a sinus tachycardia and a third heart sound. Hypertensive Retinopathy: l Grade I Thickening of arterioles. l Grade II Focal Arteriolar spasms. Vein constriction. l Grade III Hemorrhages (Flame shape), dot-blot and Cotton wool and hard waxy exudates. l Grade IV - Papilloedema INVESTIGATIONS Routine investigation of the hypertensive patient should include: l ECG l Urine stix test for protein and blood l Fasting blood for lipids (total and high- density lipoprotein cholesterol) and glucose l Serum urea, creatinine and electrolytes. Investigation of selected cases l Chest X-ray l Ambulatory BP recording l Echocardiogram l Renal ultrasound l Renal angiography l Urinary catecholamines l Urinary cortisol and dexamethasone suppression test l Plasma renin activity and aldosterone Non-pharmcological treatment l Weight reduction - BMI should be 140 mmHg), malignant hypertension (grades 3 or 4 retinopathy), hypertensive encephalopathy or with severe hypertensive complications, such as cardiac failure, should be admitted to hospital for immediate initiation of treatment. In most cases, the aim is to reduce the diastolic blood pressure to 100-110 mmHg over 24-48 hours. This is usually achieved with oral medication, e.g. atenolol or amlodipine. Blood pressure can then be normalized over the next 2-3 days. When rapid control of blood pressure is required (eg. in aortic dissection), the agent of choice is IV sodium nitroprusside. Alternatively, infusion of labetalol can be used. The infusion dosage must be titrated against blood pressure response. Management of hypertension in pregnancy l Mild hypertension can be treated with methyldopa, which has been established as being safe in pregnancy, or labetalol. Pre-eclamptic hypertension can be treated with the same agents, or nifedipine, although the only method for reversal of overt pre-eclampsia is delivery. More severe hypertension or eclampsia requires treatment with intravenous hydralazine and may even require termination of the pregnancy. PROGNOSIS The prognosis from hypertension depends on a number of features: l Level of blood pressure l Presence of target-organ changes (retinal, renal, cardiac or vascular) l Coexisting risk factors for cardiovascular disease, such as hyperlipidaemia, diabetes, smoking, obesity, male sex l Age at presentation. l Se