Pharmocology Of CVS

Question 1

What is angina pectoris

Answer 1

-disorder of the breast / chest
Cramping or constriction of the chest
Pain in jaw shoulders neck, arms
Shortness of breath, nausea , sweating

Question 2

What is responsible for the main pain symptom in angina

Answer 2

Ischaemia- reduced blood flow to the heart ! So myocardium does not receive enough oxygen to generate enough atp to pump blood to areas in the body

Affected region in myocardium release lactate,adenosine ,bradykinin, prostaglandin

Activates myocardial pain receptors

Signals sent via sensory neurons to the brain
Pain perceptions

Question 3

What was the traditional classification of angina

Answer 3

Typical Angina
-substernal chest discomfort of characteristic quality and duration
-provoked by exertion or emotional stress
-relieved by rest or nitrates in minutes

Atypical angina
2 of those synotioms

Non anginal
- only one of those symptoms

Question 4

New classification of angina ( 4 main types )

Answer 4

• stable angina - coronary heart disease
  -unstable angina -due to complications of unstable angina
  -prinzmetal angina -due to spasm in coronary arteries
  -micro vascular angina -angina symptoms but no evidence of coronary artery disease

Question 5

Stable angina

Answer 5

• root cause is atherosclerosis
• plaque build up in the arteries
• space for blood flow becomes Smaller
  -stenosis
  Oxygen is insufficient when blood has to work harder so it leads to anaerobic respiration

Question 6

Characteristics of stable angina

Answer 6

-follows set pattern
- shirt duration radiation to left arm , neck, jaw , back
-precipitated by excursion / cardiac oxygen increase demand
-nit life threatens but can be warning signs for heart attack / stroke
-relieved by rest
-symptoms attributed to myocardial ischemia

Question 7

How is an Unstable angina caused

Answer 7

Clot formation occludes artery , critical reduction in blood flow so oxygen in inadequate even at rest which leads to pain

Question 8

Characteristics of unstable angina

Answer 8

-unpredictable
-pain symptoms more severe
-happens at rest
- no trigger
Relieved by rest and medication
-patients should go hopsital

Question 9

What causes a prinzmetal angina

Answer 9

Coronary artery spasm , vasospasm produced eg by drugs like cocaine
Which causes critical reduction to blood flow making oxygen supply inadequate leading to pain

Question 10

Characteristics of prinzmetal angina

Answer 10

-occurs while resting
-rare , present in younger patients
-relieved by taking medication
Pain spreads to head, arms ,
Symptoms - heart burn , nausea,sweating , dizziness, palpitations,migraines

Question 11

What causes a micro vascular angina

Answer 11

Impaired coronary circulation which leads to reduced coronary perfusion leading to pain
Impaired vasodilation which increases constriction

Question 12

Characteristics of micro vascular angina

Answer 12

-impaired coronary circulation due to coronary micro vascular dysfunction from abnormal vasodilation or increased vasoconstrictions
-patients do not have obstructive coronary artery disease
-;-PET or CMR Is used to assess coronary micro vascular blood flow
-occurs with exertion at rest

Question 13

Treatment aims of angina

Answer 13

-enhance quality of life through reduction of symptoms
-improve prognosis and prevent complications such as MI and premature death
-cause minimal side effects

Question 14

What is angina

Answer 14

An imbalance between the demand and supply of oxygen to the heart

Question 15

What does vasosspam and thrombus lead to

Answer 15

Decreased coronary blood flow
Which leads to supply ischaemia ( inadequate blood supply due to blockage in the area) which leads to angina

Question 16

What does fixed stenosis lead to

Answer 16

-increased oxygen requirement
-which leads to demand ischemia ( extreme need for oxygen which exceeds body’s ability to supply ) which leads to angina

Question 17

Precipating factors of angina

Answer 17

• increased sympathetic activity
  -increased contractility
• increased vasoconstriction

Question 18

Role of calcium in muscle relaxation and contraction

Answer 18

• increase in cyctoplasmic calcium ions
  -in heart muscle calcium binds to troponin , in smooth it binds to calmodulin
  -in the heart troponin causes tropomyosin to move exposing myosin binding site
  -in smooth muscle calmodulin leads to phosphylation if myosin
  -cross bridge cycle
  -contraction by pulling actin along the myosin

Question 19

How are nitrates and protein kinase G involved in anti anginal pharmacology

Answer 19

• nitric oxide continually produced by the endothelium
• NO leads to production of PKG
  PKG reduces smooth musclar tone
  —myosin light chain depolarisation ,
• increased uptake of calcium by SR , less calcium means less contraction so relaxation occurs
  -potassium ion channels activated causing hyperpolarisation and closing VGCC

Question 20

Anti anginal pharmacology - nitrates

Answer 20

Eg GTN, isosorbide mono nitrate
Effects ~ peripheral venodilation -decrease intraventricular pressure- decreases cardiac preload
-arterial dilation-decrease TPR- reduced afterload
Lower oxygen demand and lower work if heart

Adverse effects -
Throbbing headaches , flushing , syncope
Postural hypotension
-reflex tachycardia

Question 21

Anti anginal pharmacology - b blockers

Answer 21

Eg atenolol , bisoprolol

-inhibits If pacemaker current in SAN which decreases heart rate
-reduce force of cardiac contractions
-reduced cardiac output and lower pressure
Leads to slower heart rate giving more time for coronary perfusion , improves myocardial oxygen supply

Adverse effects
- bronchospasm
-postural hypertension
-fatigue

Question 22

Anti anginal pharmacology - calcium channel blockers

Answer 22

Amplodipine , nifedipine ,verapamil,diltiazem

-reduce calcium ion entry to cardiac myocytes which reduce contractility
-direct coronary vasodilation
-reduce TPR
Reduce force of contraction

Adverse effects
- lower limb oedema
-flushing and headache
-reflex tachycardia
Caution- blocking calcium channels may alter electrical conduction and contractility

Question 23

Prophylactic drugs for angina

Answer 23

Aspirin -inhibits COX, reduces thromboxane A2 ,and platelet aggregation

Clopidogrel-inhibits ADP receptors on platelets , reduces aggregation

Statins-HMG CoA reductase inhibitor , reduces cholesterol levels

Question 24

For people on beta. Blockers or calcium channel blockers whose symptoms are not controlled what other drugs can they take

Answer 24

-ivabradine-inhibitor of if current in SAN which slows sinus heart rate

-Nicorandil-potassium channel activator leads to hyperpolarisation

Ranolazine- late sodium current inhibitor - improves mycardial perfusion