Hypertension Flashcards
Mention possible causes of primary HTN
- Increased cardiac output due to additional blood flow to extra adipose tissue.
- Inc VMC activity or inc constrictor response of arterioles to vasomotor tone. There is evidence of dec baroreceptor senitivity.
- Impaired Na and water excretion by the kidney leading Na & water retention
- Ang II and aldosterone are inc due to inc sympathetic activity and inc renin.
- Endothelial dysfunction & insulin resistance may be involved
GR: Baroreceptors are reset
- The baroreceptors in walls of aorta & carotid sinus show less sensitivty to sustained elevated BP
- The baroreceptor becomes set to the new high value and defend it
- The carotid sinus becomes stiffer and less deformable as a result og high arterial pressure. Then a given increase in carotid sinus pressure elicity less decrement of ABP.
Mention causes if renal hyoertension
- Renal parenchymal HTN, due to parenchymal disease (glomeruloneohritis & nephrotic syndrome) resulting in Na & water retention.
- Renovascular HTN (uni or bilateral which is called GoldBlatt HTN) due to narrowing of one or both renal arteries resulting in renal ischemia & inc renin & ang ii.
Define coarctation of aorta
It is narrowing of descending aorta above level of renal arteries leading to bilateral renal ischemia and high renin HTN, BP is 40-50% higher in UL than LL
GR: Occurrence if neurogenic HTN
Due to sudden inc in sympathetic activation with severe VC
Defect in baroreceptor, buffer nerves or tractus solitares
What is Cohn’s disease?
It is due to a tumour in the zona glomerulosa od adrenal cortex resulting in primary hyperaldosterosim.
What is Cushing disease?
Results from a tumour in the zona fasciculate of adrenal cortex & excess cortisol secretion.
Mention symptoms of pheochromocytoma
HTN occurs in episodes during stress, associated with pallor and sweating as well as hyperglycemia.
The “pills” in pill HTN are ….
Contraceptive pills containing estrogen hormone
Mention cardiac complications of HTN
- Inc afterload amd ventricular hyoertrophy, but the increase in muscle is not matched with inc blood supply leading to cardiac ischemia, dec vent compliance & diastolic dysfunction
- It causes atherosclerosis and narrowing of coronary art leading to coronary thrombosis & MI
- Hypertrophied cardiac muscle cannot compensate for inc resistance leading to HF
Explain insults to vital organs by HTN
- Brain, rupture of small vessels leading to hemorrhage and infarction, this is called stroke, if it occurs in retina it causes blindness.
- Kidney suffers from high BP may become thickened and develop atherosclerotic lesions eventually dec GFR & renal excretion of Na & water, eventually renal failure.
Define hypotension
State if diminished ABP below 100 mmHg (systolic) & 60 mmHg (diastolic)
Mention causes of chronic hypotension
Vasomotor tone is less than normal
Various types of anemia cause dec BP due to dec blood viscosity
Both cause dec TPR (anemia by dec O2 content if blood)
Decsribe the compensatory mechanisms of chronic hypotension
The dec TPR causes an increase in VR followed by an inc in CO resulting in adequate perfusion of tissues and organs. This increase compenates for the lower ABP
Define syncope
It is sudden and temorary loss of consciousness from which the pateint recovers spontaneously.