SECONDARY HYPERTENSION

Secondary hypertension is the name given to the hypertension of which the cause is known, and can be corrected in many cases to cure the hy­pertension.

Renal hypertension :

  • This is due to either renal se­retion of vasoactive compounds resulting in increased arteriolar tone or volume expansion due to distur­ance of sodium and fluid balance.
  • Uncontrolled hypertension comprises the following entities:
  • Secondary hypertension: Elevated blood pressure (BP) that results from an identifiable underlying mechanism Resistant hypertension: failure to achieve goal blood pressure (<140/90 mm Hg for the overall population and <130/80 mm Hg
  • for those with  chronic kidney disease or diabetes when a patient adheres to maximum tolerated doses of 3 antihypertensive drugs including a diuretic” Other causes: Inadequate treatment, poor patient adherence Poor control is most often due to persistent elevation in systolic BP
Secondary hypertension 1

Secondary hypertension Renovascular hypertension

Renal hypertension may be :

  • Renovascular hypertension including eclampsia and reeclamsia.
  • Renal parenchl’mal hypertension.
  • Renal vascular hypertension is due to stenosis of main or a branch of renal artery which activates the -renin angiotensin system (RAS).
  • The circulating angiotensin II causes vasoconstriction: LQ.v aldosterone secretion, sodium retention, stimulater: beren­glc nervous system a..!Jd al its direct action on:. e arterioles.
  • one half of the patients there is elevation of plasma
  • In activity RenaL.Parenchymal hypertension is due to in renal parenchymal disease with involvement of mulIe small renal vessels leading to decreased perfusion of renal tissue and bypertensiol
  • Peripheral plasma renin activity (PRA) is normal or increased
  • Cardiac output normal
  • Tilting and Valsalva maneuver have no effect
  • Blood volume is increased
  • Cardiac output increased
  • Tilting & Valsalva maneuver increase blood pressure
  • Blood volume is decreased in unilateral disease

Clinical Considerations

  • Pseudoresistance:
  • In primary care settings, this has been estimated to occur in 40–60% of hypertensive patients.
  • Poor adherence
  • White-coat effect: Prevalence estimated at 20–30%
  • Inaccurate measurement of BP:
  • Cuff too small
  • Patient not at rest; sitting quietly for 5 minutes