Myocardial infraction, pathophysiology, diagnosis and treatment

1. Myocardial Infraction
Presented by
Reshma V. Pawar
M.Pharm (Pharmacology)
Genba Sopanrao Moze College of Pharmacy,
Wagholi, Pune

2. Myocardial Infraction
Myocardial infarction commonly known
as a heart attack, is the interruption of
blood supply to a part of the heart,
causing heart cells to die. This is most
commonly due to occlusion (blockage)
of a coronary artery following the rupture
of a vulnerable atherosclerotic plaque

3. which is an unstable collection of lipids (fatty acids) and
white blood cells (especially macrophages) in the wall of
an artery. The resulting ischemia (restriction in blood
supply) and oxygen shortage, if left untreated for a
sufficient period of time, can cause damage or death
(infarction) of heart muscle tissue (myocardium).
Myocardial Infraction

4. Basic Types
Transmural
Subendocardial
Based on ECG Change
ST eievation MI
Non-ST elevation MI
Types of myocardial infracrion

5. 1) Atherosclerotic plaque
2) Acute Coronary occlusion
3) Apoptosis
4) Ventricular fibrillation
Pathophysiology of Myocardial Infraction

6. Atherosclerotic plaque
Monocyte Adhesion molecule
Monocyte migrates intima
Macrophage
Ingest &oxidizes lipoprotein molecule
Foam cells cause inflammation
Growth of intimal layer
Plaque

7. Acute Coronary occlusion
Unsmooth surface
Adhere Blood platelets
Deposition of Fibrin
RBCs entrapped & form
Blood clot
Grows until vessel occludes

8. 1) Clinical history of ischaemic type chest pain lasting
for more than 20 minutes
2) Changes in serial ECG tracings
3) Rise and fall of serum cardiac biomarkers such as
creatine kinase-MB fraction and troponin
4) Coronary Angiogram
5) Chest Cardiograph
6)Echocardiogram
Diagnosis

9. 1)Pain ,Anxiety & Apprehension :-
Opioid analgesics- Morphine sulphate 5-10mg
/Diamorphine 2.5-5mg
2) Oxygenation :-
O2 inhalation & assisted respiration if
needed.
3) Maintenance of blood volume, tissue
perfusion & microcirculation:-
Slow i.v, infusion of saline/low moi.wt. dextran
Drug Therapy in MI

10. 4) Correction of acidosis:-
Due to Lactic acid production –sod.bicarbonate
by i.v. infusion
5) Antithrombotic Therapy
Aspirin 80-160mg Daily
clopidogrel 75mg daily.
Ticagrelor 90 mg
- Glycoprotein IIb /IIIa receptor antagonist Tirofiban and
Abciximab inhibitor of thrombus formation.
Drug Therapy in MI

11. 6) Thrombolysis & reperfusion :-
Firinolytic agents i.e. plasminogen
activators streptokinase/ urokinase /alteplase
to achive reperfusion of infracted area.
7) Prevention & treatment of arrhythmia:-
Prophylactic i.v. infusion of β blockers as soon
as MI patient is seen and continued orally for few
days.(timolol 5-10mg twice day)
Drug Therapy in MI

12. Tachyarrhythmias may be treated with
lidocaine,procainamide. Bradycardia and heart
block may be managed with atropine.
8)Pump Failure:-
a) furosemide- indicated if pulmonary
wedge pressure is>20mmHg it decreases
cardiac pre-load
Drug Therapy in MI

13. b) Vasodilators- GNT(i.v.) or nitroprusside
mainly used
c) Inotropic agent- Dopamine or dobutamine
needed to augment the pumping action
9) Prevention of remodeling &
subsequent CHF:-
ACE inhibitors proven efficiency and
afford long term survival benefit.
Drug Therapy in MI

14. 10) Prevention of future attacks:-
a) Platelet inhibitors
b) β Blockers
C) Control of hyperlipidemia
Drug Therapy in MI

15. 1) Percutaneous Coronary Intervention
(PCI )
2) Coronary Artery Bypass Grafting
(CABG)A
Surgical therapy in MI

16. 1) Guyton & Hall, “Textbook of Medical Physiology.”
11th edition. Page no. 252-255.
2) Roger Walker,Cate Whittlesea,”Clinical Pharmacy &
Therapeutics”,4th edition.Page no.287-292.
3) Davidson’s Principle & Practice of Medicine, edited
by Nicki Colledge, Brian Walker, 21st edition Page no.
581-600.
4) K.D.Tripathi,” Essentials of medical pharmacology”,
6th edition Page no. 537,538.
References