Helen Lalrinpuii .
THE TOPIC –
II. DEFINITION OF MYOCARDIAL
Myocardial infarction refers to a
dynamic process by which one or more
region of the heart experiences a severe
and prolonged decrease in oxygen
supply because of insufficient coronary
blood flow, subsequently, necrosis or
death to death to the myocardial tissue
III.EPIDEMIOLOGY OF MI
• Myocardial infarction is a common presentation
of heart disease.
• WHO(2004) -12.2% death; 3 million ST-Elevated
Myocardial Infarction & 4 million of Non-ST Elevated
• (American Heart Association) – USA 1 million have
heart disease, of which ¼ die at hospital & half of these
do not reach hospital.
• India (2004)- 1.46 have myocardial infarction & 14%
die, death rate expected to double in 2015.
• Heart disease is a leading cause of death in India.
IV.ETIOLOGY & RISK FACORS OF MI
• Sedentary lifestyle.
• Tobacco user.
• Diabetes mellitus.
• Family history.
V. ANATOMY &
•Lies in thoracic cavity
•Upper part is base
and lower part is apex.
• Apex is 9cm to the
left midline at level of
5th intercostals space
& base at the level of
•Size is that of owner
A. The heart
*Outer most layer.
* Has two sacs-AS TWO SACS-
-Outer fibrous sac. .
-Inner membrance sac.
-Composed of specialised muscle.
-Network of specialised conducting fibre.
-Lines chamber, valves & blood vessel.
•Heart is divided left and
right by septum.
it into atrium and
• Right ventricular valves
has 3 flaps and left
ventricles has 2 cusp/
flap, which open when
pressure in atrium is
greater than ventricles.
•This valves are guarded
by tendinous cord called
• Superior & inferior vena cava empty their content in
• Right atrium to right ventricles valves via right atrio
ventricles & pump into pulmonary artery.
• Leaving the heart divided into left & right pulmonaries
arteries, carry venous blood to the lungs.
• Changes in the gases take place in the lungs.
• 2 pulmonary veins back to left atrium, passed through
left atrio ventricles valves enter the left ventricles &
pump into aorta .
• Aorta -> the different part of the body.
BLOOD SUPPLY TO THE HEART:
1. Arterial supply:
• Right & left coronary arteries..
• Receives 5% of total blood via coronary
• Coronary arteries form vast network of
• Most venous blood is collected in cadiac vein
forming coronary sinus open onto right
• Remainder passes- heart chamber via venous
NERVES SUPPLY TO THE HEART
• Autonomic nerves originated in cardio
vascular centre in medulla oblongata.
• Vagus nerve (parasympathetic nervous system
• Sympathetic nervous system.
VI.PATHOPHYSIOLOGY OF MI
Plaque ruptured / thrombus formation.
Occlusion of the artery.
Vasospasm of the blood vessel's.
Decrease oxygen supply.
Increase oxygen demand.
VIII. DEGREE /ZONE OF DAMAGES IN
A.ZONE OF NECROSIS:
• Extensive & complete O2 deprivation.
• Irreversible damage zone.
B. ZONE OF INJURY:
• Area surrounding necrosis.
• Inflamed & injured but viable.
C. ZONE OF ISCHEMIA:
• Surrounding injury area.
• Not endangered & viable.
VII. CLASSIFICATION OF MI
A. ST Segment Elevated MI (STEMI)
B. Non ST Segment Elevated MI (NSTEMI)
XI. PROGNOSIS OF MI
• Depend on intensity & extensity of damages.
• Complicated with heart block & Right
Ventricular failure has worst prognosis.
• Definitive & prompt intervention has good
A. Patient history.
B. Electro cardiogram (ECG).
C. Echo cardiogram.
D. Laboratory test:
* White blood cell (WBC).
E. Magnetic Resonance Imaging
NT OF MI.
A.Baseline Rx -
E. MINIMAL INVASIVE DIRECT
CORONARY ARTERY BYPASS
• Its different from CABG is that median
sternotomy is eliminated.
• Its has smaller incission.
• A robotic system endoscopic technique is used
to place by-pass graft.
• Its advantage is that it has fewer
1. XIV. NURSING MANAGEMENT OF
MI USING NURSING PROCESS.
1. Acute pain (chest) r/t imbalance oxygen supply
& demand as evidenced by patient
verbalization of chest pain.
2. Decreased cardiac output r/t impaired
contractility as evidenced by facial pallor &
fainting in patient.
3. Altered tissue perfusion r/t coronary restenosis
& extension of infarction as evidenced by
shortness of breath & hypo/hypertension.
4. Activity intolerance r/t fatigue secondary to
decreased cardiac output & poor lung & tissue
perfusion as evidenced by fatigue with minimal
activity, inability to care for self without
dyspnea & increases heart rate.
5. Risk for injury (bleeding) r/t dissolution of
6. Knowledge deficit r/t home care & treatment
modalities as evidenced by asking numbers of
question to health personnel.