Pharmacology

Question 1

what affect does (nor)adrenaline have on HR

Answer 1

increases

Question 2

what affect does (nor)adrenaline have on contractility

Answer 2

increases

Question 3

what affect does (nora)adrenaline have on conduction velocity in AV node

Answer 3

increases

Question 4

what affect does (nora)adrenaline have on duration of systole

Answer 4

decrease

Question 5

explain the effect of (nora)adrenaline on HR

Answer 5

it increases the slope pacemaker potential (phase 4)

it reduces the threshold for AP initiation

Question 6

explain the effect of (nora)adrenaline on contractility

Answer 6

it increases phase 2 via enhancing Ca2+ influx

increases sensitisation of contractile proteins to Ca2+

Question 7

explain the effect of (nora)adrenaline on systole duration

Answer 7

increases uptake of Ca2+ into SR

Question 8

what does (nora)adrenaline act upon in heart

Answer 8

B1-adrenoceptors in nodal and myocardial cells

Question 9

what do B1-adrenoceptors do once they are activated by (nora)adrenaline

Answer 9

couple to Gs protein which activates adenylyl cyclase to increase [cAMP]

Question 10

what does B1-adrenoceptors couple with

Answer 10

Gs protein

Question 11

what does Gs protein activate

Answer 11

adenylyl cyclase

Question 12

what does activated adenylyl cause an increase in

Answer 12

[cAMP]

Question 13

what affect does acetylcholine have on HR

Answer 13

decreases

Question 14

what affect does acetylcholine have on contractility

Answer 14

decrease

Question 15

what affect does acetylcholine have on conduction in AV node

Answer 15

decrease

Question 16

explain the effect of acetylcholine on HR

Answer 16

increases threshold for AP initiation

decreased slope of pacemaker potential via hyperpolarization caused by opening of GIRK channels

Question 17

explain the effect of acetylcholine on contractility

Answer 17

decrease in phase 2 due to decreased Ca2+ entry

Question 18

explain the effect of acetylcholine on conduction in AV node

Answer 18

decreased activity of voltage activated Ca2+ channels

hyperpolarization via opening K+ channels

Question 19

what does acetylcholine act upon

Answer 19

M2-muscarinic cholinoceptors in nodal cells

Question 20

what does M2-muscarinic cholinoceptors do once activated by acetylcholine

Answer 20

couples to Gi protein which decreases the activity of adenylyl cyclase reducing [cAMP] it also opens GIRK channels causing hyperpolarization of SA node

Question 21

what do M2-muscarinic cholinoceptors couple to

Answer 21

Gi proteins

Question 22

what do Gi proteins do once activated by M2-muscarinic cholinoceptors

Answer 22

decrease activity of adenylyl cyclase

open GIRK channels

Question 23

what does opening on GIRK channels cause (SA node)

Answer 23

hyperpolarization of SA node

Question 24

what does a decrease in adenylyl cyclase activity result in

Answer 24

decrease in [cAMP]

Question 25

what is ivabradine

Answer 25

selective blocker of HCN channels

Question 26

describe the affect of ivabradine on HR

Answer 26

decrease

Question 27

what is the clinical use of ivabradine

Answer 27

treatment of angina (if uncontrolled with beta blockers and Calcium channel blockers) chronic HF

Question 28

describe the mechanism of ivabradine

Answer 28

blocks HCN channels which decreases the slope of pacemaker potential

Question 29

what do HCN channels do

Answer 29

mediates the "funny current" which modulates the pacemaker potential

Question 30

what is the full name of HCN channels

Answer 30

cyclic AMP gated HCN channels

Question 31

explain the process of contraction in cardiac muscle

Answer 31

ventricular AP causes L-type Ca2+ to open during phase 2 this causes a Ca2+ influx into the cytoplasm activating RyR2 on the SR causing Ca2+ to flow out of the SR (this process is called CICR) Ca2+ binds to troponin C and shifts the tropomyosin out of the actin cleft allowing cross-bridge formation contraction occurs via the sliding filament mechanism

Question 32

explain the process of relaxation in cardiac muscle

Answer 32

Ca2+ dissociates from troponin C and leaves the cell in 2 ways: 1. via NCX1 (Na+/Ca2+ exchanger) 2. returns to the SR via SERCA (Ca2+ATPase of Ca+)

Question 33

give examples of adrenoceptor agonist

Answer 33

adrenaline | dobutamine

Question 34

what effects do adrenoceptor agonist have on the heart (5)

Answer 34

increase: force, HR, CO, O2 consumption decrease: cardiac efficiency

Question 35

what can long term use of adrenoceptor agonist cause

Answer 35

arrhythmias

Question 36

what type of adrenoceptor agonist is adrenaline

Answer 36

alpha AND beta agonist

Question 37

what are the clinical uses of adrenaline

Answer 37

``` cardiac rest (IV) anaphylactic shock (IM) ```

Question 38

what affect does adrenaline have on HR and force, what is it acting on

Answer 38

increases | β1

Question 39

what affect does adrenaline have on blood vessels, what is it acting on

Answer 39

constricts the skin, mucosal, and abdomen vessels | α1

Question 40

what affect does adrenaline have on coronary arteries, what is it acting on

Answer 40

dilatation | β2

Question 41

what type of adrenoceptor agonist is dobutamine

Answer 41

selective beta

Question 42

what are the clinical uses of dobutamine

Answer 42

acute heart failure (IV)

Question 43

give examples of β-adrenoceptor antagonists

Answer 43

propranolol, atenolol, bisoprolol, metoprolol

Question 44

give examples of SELECTIVE β-adrenoceptor antagonists

Answer 44

atenolol, bisoprolol, metoprolol

Question 45

give examples of NON SELECTIVE β-adrenoceptor antagonists

Answer 45

propranolol

Question 46

what type of β-adrenoceptor antagonist is propranolol

Answer 46

non selective (β1 and β2)

Question 47

what type of β-adrenoceptor antagonist is atenolol

Answer 47

selective (β1)

Question 48

what type of β-adrenoceptor antagonist is bisoprolol

Answer 48

selective (β1)

Question 49

what type of β-adrenoceptor antagonist is metoprolol

Answer 49

selective (β1)

Question 50

what affect do β-adrenoceptors have at rest

Answer 50

none

Question 51

what affect do β-adrenoceptors have during exercise or stress (6)

Answer 51

decreased: HR, force of contraction, CO , maximal exercise tolerance, coronary vessel diameter, myocardial O2 requirement

Question 52

what are the clinical uses of β-adrenoceptors antagonists (4)

Answer 52

angina, hypertension, arthymias (AF, SVT), heart failure

Question 53

what are the adverse effects of β-adrenoceptors antagonists

Answer 53

bronchospasms, aggravation of cardiac failure, bradycardia, cold extremities

Question 54

in what condition are β-adrenoceptors contraindicated

Answer 54

asthma

Question 55

give an example of muscarinic receptor antagonist

Answer 55

atropine

Question 56

what are the clinical uses of atropine

Answer 56

bradycardia (1st line) MI (IV) anticholinesterase poisoning

Question 57

what are the affect of muscarinic receptor antagonists

Answer 57

increased HR

Question 58

give an example of a cardiac glycoside

Answer 58

digoxin

Question 59

what are the clinical uses of digoxin

Answer 59

``` acute HR (IV) chronic HR (orally) ```

Question 60

what are the side effects of digoxin

Answer 60

heart block/arrhythmias disturbance of colour vision vomiting/diarrhoea/nausea

Question 61

what is the direct action of digoxin

Answer 61

shortens AP and refractory period

Question 62

what is the indirect action of digoxin

Answer 62

increases vagal activity

Question 63

what is the mechanism of digoxin

Answer 63

binds to alpha-subunit of Na+/K+ ATPase in competition with K increases contractility by blocking the sarcolemma ATPase

Question 64

what is the mechanism of levosimendan

Answer 64

binds to troponin C and densities it to the action of Ca2+ opens K+ channels

Question 65

what is the affect of levosimendan

Answer 65

increases contractility

Question 66

what is the affect of digoxin

Answer 66

increases contractility

Question 67

what is the affect of am- and mil-rinone

Answer 67

increases contractility

Question 68

what is the mechanism of am- and mil-rinone

Answer 68

inhibits phosphodiesterase (PDE) in cardiac and smooth muscle cells = increase [cAMP]

Question 69

what is the clinical use of am- and mil-rinone

Answer 69

acute HF (IV)

Question 70

what is the clinical use of levosimendan

Answer 70

acute decompensated HF (IV)