INTERNAL MEDICINE

Hypertension

Def: Blood pressure is defined as the pressure that is

put on the walls of the arteries as blood is pumped through the circulatory system.

Hypertension

Types of HTN: A)Essential HTN or Primary HTN B)Secondary HTN

Hypertension

Causes: A)Essential HTN or Primary HTN- Idiopathic Age Genetic and familial factor Socioeconomic condition Obesity

Hypertension

Causes: B)Secondary HTN- Adrenal gland tumor Alcohol abuse Anxiety and stress Arteriosclerosis Birth control pills Coarctation of the aorta Cocaine use Cushing syndrome Diabetes

Hypertension

Causes: B)Secondary HTN- Kidney disease, including: Glomerulonephritis Kidney failure Renal artery stenosis Renal vascular obstruction or narrowing

Hypertension

Causes: B)Secondary HTN- Corticosteroids Pregnancy Primary hyperaldosteronism Renal artery stenosis

Hypertension classificationCategory SBP mm Hg DBP mm Hg

Normal <120 <80

Prehypertension 120-139 80-89

Hypertension stage 1 140-159 90-99

Hypertension stage 2 ≥160 ≥100

Hypertension

Pathogenesis of hypertension: The pathogenesis of essential hypertension is

multifactorial and highly complex. Multiple factors modulate the blood pressure for adequate tissue perfusion and include humoral mediators, vascular reactivity, circulating blood volume, vascular caliber, blood viscosity, cardiac output, blood vessel elasticity, and neural stimulation. A possible pathogenesis of essential hypertension has been proposed in which multiple factors, including genetic predisposition, excess dietary salt intake, and adrenergic tone, may interact to produce hypertension. Although genetics appears to contribute to essential hypertension, the exact mechanism has not been established.

Hypertension

Pathogenesis of hypertension: The natural history of essential hypertension evolves

from occasional to established hypertension. After a long invariable asymptomatic period, persistent hypertension develops into complicated hypertension, in which target organ damage to the aorta and small arteries, heart, kidneys, retina, and central nervous system is evident. The progression begins with prehypertension in persons aged 10-30 years (by increased cardiac output) to early hypertension in persons aged 20-40 years (in which increased peripheral resistance is prominent) to established hypertension in persons aged 30-50 years, and, finally, to complicated hypertension in persons aged 40-60 years.

Hypertension

Pathogenesis of hypertension: One mechanism of hypertension has been

described as high-output hypertension. High-output hypertension results from decreased peripheral vascular resistance and concomitant cardiac stimulation by adrenergic hyperactivity and altered calcium homeostasis. A second mechanism manifests with normal or reduced cardiac output and elevated systemic vascular resistance due to increased vasoreactivity. Another (and overlapping) mechanism is increased salt and water reabsorption (salt sensitivity) by the kidney, which increases circulating blood volume.

Hypertension

Pathogenesis of hypertension: The vasoreactivity of the vascular bed, an important

phenomenon mediating changes of hypertension, is influenced by the activity of vasoactive factors, reactivity of the smooth muscle cells, and structural changes in the vessel wall and vessel caliber, expressed by a lumen-to-wall ratio. Patients who develop hypertension are known to develop a systemic hypertensive response secondary to vasoconstrictive stimuli. Alterations in structural and physical properties of resistance arteries, as well as changes in endothelial function, are probably responsible for this abnormal behavior of vasculature. Furthermore, vascular remodeling occurs over the years as hypertension evolves, thereby maintaining increased vascular resistance irrespective of the initial hemodynamic pattern.

Hypertension

Clinical features: Most of the time, there are no symptoms.

Symptoms that may occur include: Chest pain Confusion Ear noise or buzzing Irregular heartbeat Nosebleed Tiredness Vision changes Headache Vertigo Palpitation Dizziness

Hypertension

Investigation: Urine analysis CXR P/A view ECG Plasma lipid profile BUN Sr.creatitine Plasma electrolytes IVU USG of KUB Angiography MRI

Hypertension

Management: A)general management Diet- avoidance of excess salt consumption and

alcohol Weight reduction in obese Stop smoking Exercise and relaxation

Hypertension

Management: B)Antihypertensive drug therapy 1.Diuretics- Thiazide diuretics 2.5 mg daily Potassium sparing diuretics 50-200 mg daily Loop diuretics 40 mg daily

Hypertension

Management: B)Antihypertensive drug therapy β adrenoceptor antagonists- Atenolol 50-100 mg daily Metoprolol 100-200 mg daily Propranolol 40-120 mg thrice daily Labetalol 100-200 mg twice daily(combined α

and β adrenoceptor antagonist)

Hypertension

Management: ACE inhibitors- Captopril 25 to 75 mg 12 hrly Enalapril 20 mg daily Lisinopril 10 mg daily Ca-antagonists- Diltiazem 60 mg 8 hrly Amlodipine 5-10 mg daily Nifedipine 20 mg twice daily Drug combination- β blockers and thiazide combination