Friday, September 16, 2011

CARDIOVASCULAR-HYPERTENSION-II


  • There is no definite dividing line between normal and high blood pressure, arbitrary values have been established to define hypertension.
  • According to JNC VII classification Normal B.P < 120/80 mm of Hg.
  • Hypertension stage I-systolic B.P. 140-159 mm of Hg ; Diastolic B.P. 90-99 mm of Hg  Stage II-systolic B.P. > 160 mm of Hg ; Diastolic B.P.>100
  • Those lying between 120/80 - 139/89 mm of Hg are in prehypertensive condition.
  • Those with B.P 200/140 mm of Hg are called as malignant hypertensives.
  • WHO has used 160/95 mm Hg as upper limit of normal.
  • Normal B.P. value also depend on the age of patient. 

  • Type of Hypertension-Primary and secondary
  • Primary-Essential
  • Secondary-Renal diseases;Cushing syndrome;Conn's syndrome;Phaeochromocytoma;Hyperparathyrodism;Myxodema(hypothyroidism)
  • Precipitating factors for Essential hypertension-
  1. Age
  2. Sex(males>females)
  3. Smoking
  4. Alcoholism
  5. Diabetes
  6. Obesity
  7. Anxiety
  8. High table salt intake
  • Drugs used-
  1. ACE inhibitors
  2. Angiotensin antagonist
  3. Beta blockers
  4. Diuretics
  5. CCB
  • Cardiovascular risk factors-Age>60 yr;Family history;Smoking;Alcoholic;Dyslipidemia(LDL high HDL low);Diabetes mellitus;Hypertension
  • When risk is assessed as low or medium,first try to decrease B.p by using non pharmacological methods and keep monitoring the B.P. for 3 to 6 months.
  • Drugs should be started when B.P continues to remain above 140/90 mm of Hg.
  • Except for grade III B.P (180/110),start with drug mono therapy.
  • Initiate therapy at low dose.Increase the dose gradually
  • If response is not desirable than add a drug from another group.
  • One ingredient of the drug should be thiazide.
  • Diuretics,ACE inhibitors,CCB all increases plasma renin activity and beta blockers reduce plasma renin.
  • ACE inhibitors are the most appropriate anti hypertensives to be used in patients with Diabetes,nephropathy,CHF,LVF.They are though contraindicated in bilateral renal artery stenosis,pregnancy and hyperkalemia.
  • Beta blockers-They are mild anti hypertensives.Indicated in Angina or post MI cases,high renin cases  and pregnancy induced hypertension.They are avoided in CHF,LVF,Asthmatics,conduction defects,Diabetes.
  • Calcium channel Blockers-They are to be used in cases of asthma,low renin hypertension,pregnancy induced hypertension.Should be avoided in cases of conduction defects,CHF,LVF,Post MI cases.
  • Diuretics-They are to be used in low renin hypertension,Renal diseases,CHF,LVF,angina,post MI hypertension.To be avoided in pregnancy,hypokalemia(not with potassium sparing diuretics),Diabetes.
  • Nifedipine decreases insulin release but this is not seen with other long acting DHP's so they can be safely used in diabetics.
  • Potassium is must for insulin action.Diuretics for that reason should be avoided in diabetics but can be given with potassium sparing diuretics.
  • Furosemide is a weaker anti hypetensive than thiazides.They are to be given only when there is a chronic renal failure,CHF or resistance to thiazide.
  • Diuretics potentiate all other anti hypertensive action.They are synergistic to ACE inhibitors. 
  • Alpha blockers(parazosin,terazosin) are found to be more effective in reducing B.P than Beta blockers.They are anticholinergic,and can be administered safely in diabetics.
  • ACE+Diuretics/Angiotensin antagonist+Diuretics are mostly used drug regime used regularly.

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