Week 8

Question 1

What is the clinical definition of hypertension?

Answer 1

• sustained daytime BP > 135 mmHg and/or > 85 mmHg diastolic
• sometimes isolated as systolic or diastolic

Question 2

Primary (essential) hypertension makes up how many cases of hypertension? What is the cause?

Answer 2

90%; idiopathic

Question 3

If cause of hypertension is known, it is considered…

Answer 3

secondary hypertension

Question 4

The risk of cardiovascular disease double with increments of ____ mmHg above _____ mmHg

Answer 4

20/10; 115/75

Question 5

What are the risk factors for hypertension?

Answer 5

• age
• family history
• obesity
• diet e.g. high salt intake
• low physical activity
• excess alcohol, smoking, stress

Question 6

What are the effects of uncontrolled hypertension?

Answer 6

• endothelial cell injury (atherosclerosis)
• cardiac consequences (CAD, left ventricular hypertrophy (due to higher afterload), heart failure)
• organ damage (kidneys, brain, eyes)

Question 7

What is the neural mechanism of blood pressure regulation?

Answer 7

baroreceptors in carotid arteries → info to medulla

Question 8

What is the renal/hormonal mechanism of blood pressure regulation

Answer 8

• ADH leadts to + H2O resporption → increased BV
• glomaruler filtration rate
• renin release

Question 9

What is the vascular mechanism of blood pressure regulation

Answer 9

endothelial cells → increase in nitric oxide (→ vasodilation) or increase in endothelin I (→ vasoconstriction)

Question 10

What is the pathophysiology of primary hypertension?

Answer 10

• elevation in blood volume (due to defect in Na+; increased Na= due to excess Na+ intake and/or resorption) → increased MAP
• increased peripheral vascular resistance
  → endothelial cell dysfunction → promoted vasocontriction
  → activation of RAAS
  → increased activation of SNS → increased cardiac output and heart rate

Question 11

What is the treatment for hypertension?

Answer 11

pharmaceuticals: vasodilators, diuretics, cardioinhibitory drugs
diet: DASH diet, reduce Na+, reduce caffine intake (positve inotrope)
other lifestyle modifications: increased PA levels, smoking cessation, decrease alcohol intake, decrease stress

Question 12

What is post exercise hypotension

Answer 12

• lowering physiological response after exercise
• observed following multiple types of exercise; likely due to vasodilation
• if done daily, ideal dose as treatment for reducing BP

Question 13

What is acute hypotension?

Answer 13

• inadequate tissue perfusion → tissue ischemia/hypoxia, cellular damage (we maintain tissue perfusion by maintaining BP)

Question 14

What are the general signs & symptoms of shock?

Answer 14

• tachycardia
• decreased urine output
• dizziness, feeling faint, altered mental status

Question 15

What are the 5 major classifications of shock?

Answer 15

• hypovolemic
• cardiogenic
• anaphylactic
• septic
• neurogenic

Question 16

What are the two types of “cold” shock?

Answer 16

hypovolemic & cardiogenic

Question 17

What is ‘cold’ shock? What is the compensation?

Answer 17

• decreased cardiac output
• compensation: vasoconstriction → increased resistance → increased MAP (blood flow redirected to vital organs)

Question 18

What is hypovolemic shock?

Answer 18

• hemorrhagic & non-hemorrhagic (diarrhea, vomiting)
• decreased blood volume → decreased venous return → decreased CO

Question 19

What is cardiogenic shock?

Answer 19

• problems with heart function (e.g. heart failure, arrhythmia, myocardial infarction, valve dysfunction) → decreased ability for heart to pump → CO

Question 20

What are the types of “warm” shock?

Answer 20

anaphylactic and septic

Question 21

What is ‘warm’ shock? What is the compensation?

Answer 21

• decreased systemic vascular resistance due to peripheral vasodilation
• compensation: increased HR

Question 22

What is anaphylactic shock?

Answer 22

the most extreme reaction to an allergen
- mast cells release histamine & bradykinin → vasodilation, edema, brochoconstriction
- treatment: IM epinephrine → increased CO, smooth muscle relax (airways), vasoconstriction

Question 23

What is septic shock?

Answer 23

e.g. due to an infection in bloodstream
- macrophage activation → cytokine release → vasodilation
- treatment: IV fluids & antibiotics

Question 24

What is neurogenic shock?

Answer 24

• loss of sympathetic tone
  → autonomic balance tips towards PNS leading to vasodilation & bradycardia

Question 25

What are the causes of neurogenic shock?

Answer 25

→ spinal cord injury → traumatic brain injury → vasovagal reflex (overreaction of vagus nerve → an abnormal response to pain, fear, emotion, sight of blood etc.)

Question 26

What is orthostatic hypotension?

Answer 26

sudden, sustained drop in BP by standing up from a sitting or laying position → SBP decreases by at least 20 mmHg or DBP decreases by at least 10 mmHg for the first 3 mins in upright position

Question 27

What are the causes of orthostatic hypotension?

Answer 27

→ impaired baroreceptor reflex function, hypovalemia, blood pooling in legs → most commonly due to medication (anti-hypertensives, diuretics, vasodilators) → increased risk in older adults

Question 28

What are the signs and symptoms of orthostatic hypotension?

Answer 28

pallor, vertigo, blurred vision, feeling faint, dizziness, nausea

Question 29

What is the treatment for orthostatic hypotension?

Answer 29

- water & salt intake, compression stalkings, sleeping in a slight incline - leg resistance exercise

Question 30

What are cardiac arrhythmias? What are the consequences?

Answer 30

abnormalities in either rate (automaticity) or in path of electrical conduction - consequences: can lead to disorganized contractions → impaired cardiac output

Question 31

What are the two heart arrythmia abnormalities in rate? They are due to an issue with...

Answer 31

- sinus bradycardia and sinus tachycardia - due to an issue with automaticity

Question 32

What is sinus tachycardia?

Answer 32

HR is faster than normal (> 100 bpm)

Question 33

What is sinus bradycardia?

Answer 33

HR is slower than normal (<60 bpm)

Question 34

How is the automacity of the heart normally modulated?

Answer 34

SA node automatically sets pace of the heart (no NS input required) - SNS: epinepherine & norepinepherine released onto SA node cells & bind to beta-adrenergic receptors → increased phase 4 slope → increased SA node AP frequency - PNS: acetylcholine released onto SA node cells & bind to 'muscarinic' receptors → decreased phase 4 slope → decreased SA node AP frequency

Question 35

Increase automaticity is due to...

Answer 35

increased sympathetic nervous system activity

Question 36

What are the 5 reasons for increased automaticity?

Answer 36

1. hypovolemia → decreased MAP → + baroreceptors → + SNS 2. hypercapnia (high blood CO2) of hypoxia (low blood CO2) → + chemoreceptors → + SNS 3. Pain or anxiety → fight or flight → + SNS 4. increased metabolic activity of pacemaker cells → increased body temo, hyperthyroidism 5. Drugs that act like NE or Epinepherine → cocaine or meth

Question 37

What are the 4 reasons for decreased automaticity?

Answer 37

1. increased parasympathetic NS activity → vasovagal reflex 2. decreased metabolic activity of pacemaker cells → decreased body temperature, hypokalemia 3. electrolyte imbalance → decreased excitability of SA node 4. heart damage or disease → leading to slowed electrical conduction

Question 38

Arrhythmias due to altered electrical conduction can happen as a result of triggered activity. What does this mean?

Answer 38

irritable area somewhere in the atria or ventricles that trigger 'ecotopic' firing (spontaneous action potentials fired outside of normal stimulus from conduction system)

Question 39

Arrhythmias due to altered electrical conduction can happen as a result of re-entry circuits. What does this mean?

Answer 39

abnormal conduction pathway is formed either due to an additional 'accessory' path or a block in normal path

Question 40

What are the 3 common arrhythmias to know?

Answer 40

- premature ventricular contractions, paroxysmal supraventricular tachycardia, fibrillation

Question 41

What causes premature ventricular contractions?

Answer 41

- triggered activity: an eletrical signal is initiated by the Purkinji fibers instead of the SA → ventricles contract 'prematurely' → a brief pause follows before normal rhythm returns

Question 42

What causes paryoxysmal supraventricular tachycardia?

Answer 42

- next conduction pathway that begins somewhere in the atria (outside of normal conduction) → new signal travels down to the ventricles → ventricular tachycardia - begins and ends suddenly

Question 43

What is fibrillation?

Answer 43

electrical activity independent of SA node → chaotic contractions

Question 44

What is atrial fibrillation? What are the symptoms?

Answer 44

heart still functions as a pump symptoms: palpitations, chest discomfort, shortness of breath, dizziness

Question 45

What is ventricular fibrillation?

Answer 45

heart does not function as an effective pump - collapse (electrical shock required to reset normal sinus rhythm)

Question 46

What is the treatment for arrythmias?

Answer 46

- drugs that control HR & rhythm: beta blockers or Na+, K+, or Ca2+ channel blockers - ablation therapy: map out the electrical activity of heart → destroy specific region of heart tissue causing issue - pacemaker implantation: regulated rhythm through low energy electrical pulses → implantable cardio defibrillator: senses a stopped heart & delivers a strong electrical shock to restart the heart