Hypertension

Question 1

Mention possible causes of primary HTN

Answer 1

1. Increased cardiac output due to additional blood flow to extra adipose tissue.
2. Inc VMC activity or inc constrictor response of arterioles to vasomotor tone. There is evidence of dec baroreceptor senitivity.
3. Impaired Na and water excretion by the kidney leading Na & water retention
4. Ang II and aldosterone are inc due to inc sympathetic activity and inc renin.
5. Endothelial dysfunction & insulin resistance may be involved

Question 2

GR: Baroreceptors are reset

Answer 2

1. The baroreceptors in walls of aorta & carotid sinus show less sensitivty to sustained elevated BP
2. The baroreceptor becomes set to the new high value and defend it
3. 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.

Question 3

Mention causes if renal hyoertension

Answer 3

1. Renal parenchymal HTN, due to parenchymal disease (glomeruloneohritis & nephrotic syndrome) resulting in Na & water retention.
2. 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.

Question 4

Define coarctation of aorta

Answer 4

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

Question 5

GR: Occurrence if neurogenic HTN

Answer 5

Due to sudden inc in sympathetic activation with severe VC

Defect in baroreceptor, buffer nerves or tractus solitares

Question 6

What is Cohn’s disease?

Answer 6

It is due to a tumour in the zona glomerulosa od adrenal cortex resulting in primary hyperaldosterosim.

Question 7

What is Cushing disease?

Answer 7

Results from a tumour in the zona fasciculate of adrenal cortex & excess cortisol secretion.

Question 8

Mention symptoms of pheochromocytoma

Answer 8

HTN occurs in episodes during stress, associated with pallor and sweating as well as hyperglycemia.

Question 9

The “pills” in pill HTN are ….

Answer 9

Contraceptive pills containing estrogen hormone

Question 10

Mention cardiac complications of HTN

Answer 10

1. 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
2. It causes atherosclerosis and narrowing of coronary art leading to coronary thrombosis & MI
3. Hypertrophied cardiac muscle cannot compensate for inc resistance leading to HF

Question 11

Explain insults to vital organs by HTN

Answer 11

1. Brain, rupture of small vessels leading to hemorrhage and infarction, this is called stroke, if it occurs in retina it causes blindness.
2. Kidney suffers from high BP may become thickened and develop atherosclerotic lesions eventually dec GFR & renal excretion of Na & water, eventually renal failure.

Question 12

Define hypotension

Answer 12

State if diminished ABP below 100 mmHg (systolic) & 60 mmHg (diastolic)

Question 13

Mention causes of chronic hypotension

Answer 13

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)

Question 14

Decsribe the compensatory mechanisms of chronic hypotension

Answer 14

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

Question 15

Define syncope

Answer 15

It is sudden and temorary loss of consciousness from which the pateint recovers spontaneously.

Question 16

Enumerate vascular causes of syncope

Answer 16

Vascular: vasovagal, postural, carotid sinus syndrome, mictration, cough syncope.

Question 17

Mention causes of vasovagal syncope

Answer 17

Severe pain

Strong emotions esp sight of blood, fear or hearing bad news

Question 18

Describe pathophysiology of vasovagal syncope

Answer 18

There is cerebral cortex firing to vagal nucleus causing cardiac deceleration and hypthalamic symp VD center. This sudden burst of autonomic activity produces bradycardia and peripheral vasodilation and pooling of bloof in the extermities.

Question 19

Pathophysiology of Carotid sinus syndrome

Answer 19

The carotid sinus is very sensitive to mild pressure over the neck
This leads to inhibition of vasoconstrictir center, stimulation of CIC, activation of hypothalamic vasodilator center resulting in drop of ABP.

Question 20

Mention causes of postural syncope

Answer 20

Long recumbency in bed due to bone fracture or severe illness
Loss of blood volume as in hemorrhage
Intake of alpha blockers which stops venoconstriction (one of the 2 physiological antigravity mechanisms)
Returning to earth from spaceflights

Question 21

Mention cardiac causes of syncope

Answer 21

Cardiac: Stocks-Adams syndrome (heart block), short runs of ventricukar fibrillation, obstruction of blood flow out of the heart, sick sinus syndrome, myocardial infarction, effort syncope.

Question 22

GR: Falling to the ground can paradoxically be beneficial in postural syncope

Answer 22

If ABP drops below level for cerebral autoregulation, cerebral flow is dependent on systemic ABP, dec cerebral blood flow, cessation of brain functions, loss of muscle contraction and falling to the ground, removal of effect of gravity, inc VR, COP & ABP, restoration of cerebral perfusion & regaining of consciousness.

Question 23

GR: Occurrence if cough syncope

Answer 23

Due to increased intrathoracic pressure which dec VR, CO & ABP by compression of veins.

Question 24

GR: Occurrence of micturation syncope

Answer 24

Due to comination of high facilitation of parasympathetic innervation during voiding causing bradycardia combined with orthostasis.

Question 25

GR: Occurrence of effort syncope

Answer 25

Due to obstruction of blood flow out of the heart caused by narrow heart valve or thick heart muscle due to inability to inc CO to meet the increased demands of tissues particularly common in patient with aortic and pulmonary stenosis.