active coronary syndroms

8/8/2019 Active Coronary Syndroms

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Acute coronary

SyndromesBy

Dr N Aravinthan


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Pathophysiology

Factors those encourages the premature

coronary arteries narrowing

a) Smokingb) Hypertension

c) Hypercholesterolemia

d) Diabetes mellitus

e) Obesity

f) Family history

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Clinical scenarios

A. Stable angina Only occurs with exercise

Pain last for < 30ml

B. Unstable angina Typical chest pain at rest

Pain last for < 30min

C. Myocardial infarction

Un remitting , lasting several hours Sweating, nausea

Sometimes vomiting and breathlessness

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Diagnosis of MI

a. Typical history

b. ECG changes

c. Elevation of serum cardiac

enzymes

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ECG

Complete occlusion of coronary artery causingfull thickness MI(STEMI)

Partial occlusion-ST depression/ T-waveinversion(NSTEMI)

Site of MI suggested by the ECG- importantprog-significant

E.g. Anterior MI V2-V4 leads changes Occlusion of left anterior descending artery

Lead to left ventricle wall affected worse prognosis

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Cardiac enzymes elevation

Troponins- I and T- prolong release pattern up

to 10 days. They are more cardiac specific

However not specific for ischemic injuryE.g. myocarditis, pulmonary embolus

and arrhythmias

CKMB-best use in find out timing of aninfarct or size of the infarct

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Other investigations

Echo - regional wall motion abnormalityventricular septal defect etc

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Mx-routine measures

A. Relieve chest pain Nitroglycerin(0.4mg sublingual tablets or aerosol spray) given

up to 3 doses

If chest pain persist

Morphine 5 mg given by slow IV; can be repeated every 5 to 10 minB. Antiplatelet therapy

Chewable aspirin 150-300mg-irreversible inhibition of plateletaggregation. this initial dose fallowed by 75-150 mg daily dose

Clopidogrel inhibit ADP-mediated platelet aggregations300mg fallowed by 75mg daily

Combined therapy with both-have very law mortality thaneach alone

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Mx cont..

receptor blockade atenolol and metoprolol

Recommended for all ACS patients except those

with bradycardiaOral therapy is suitable for most cases

IV form to pt with HT or Tachyarrhythmias

Oral- 50mg every 6 hours for 48 hours.

Iv form add 5 mg metoprolol to 50 ml DW and infuseover 15-30min. Repeat every 6 hours

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Mx cont..o ACE inhibitors

o reduce cardiac work

o also useful in inhibition of post MI cardiac

remodelingo Can be useful in all patient except severe

hypotension, SK > 2.5 mg/all and bilateral

renal artery stenosis

o Oral therapy only recommended doses 5 mg

enalapril/D

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Reperfusion therapy

thrombolytic

mechanical

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Thrombolytic

Indications

Onset of chest pain within 12 hours

12 lead ECG

shows ST elevation in two contiguousleads or a new left bundle branch block

Coronary angioplasty not immediately available

No hypotension or evidence of heart failure

No contraindication to thrombolytic therapy

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Contraindications to thrombolytic

therapy Absolute

previous hemorrhagic stroke

Any stroke within previous 2 months

Intracranial neoplasm

Active bleeding within previous month(except menstrual)

aortic dissection

Major surgery in last 3 weeks

Relative Stroke > 2 months < 1 2months

Pregnancy

Active peptic ulcer disease

Serve hypertension on presentation(> 180/110 mm hg)

Surgery/trauma within previous month

Bleeding diathesis

CPR > 10 min

Non compressible vascular puncture

allergy

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Thrombolytic agents

Agent Dose comments

Streptokinase

(SK)

1.5 million UTV over 60

min

First thrombolytic agent

Side effects fever, allergic

reaction etc

Alteplase (TPA) 15 mg IV holus

+0.75 mg/kg 30 min

+0.75 g/kg 60 min

Most frequently used

Fewer side effects

Reteolase 10 unit in holus repeat in

30 min

Rapid clot lysis than TPA bolus

doses easier to give

Plasmin

Plasminogen

Bresks tinrin

strands

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Problems with thrombolytic agents

A. bleeding Systemic fibrinolysis with depletion of circulating fibrinogen

levels

Interacerebral haemorrhages 0.5 1%

Severe bleeding- treated with cryoprecipitate, fresh frozenplasma, antifribrinolytic agents epsilon aminocaproic acid

B. Re occlusion this risk can be treated with antithrombotictherapy Asprin inhibit formation of thromboxane

Platelet glycoprotein inhibitors inhibit platelet aggregationsEg tirofiban, abciximab

ADP mediated platelet inhibitors - clopidogrel

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Percutaneus coronary angioplasty

Use of balloon tipped catheters with or

without a stent to open occluded arteries

Several clinical trials showsPC

A havingreduction in both mortality rate and rein -

farction rate than thrombolytic therapy who

present within 12 hours

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Early complications of ACS

I. Mechanical

a) Acute mitral regurgitation result of papillary

muscle rupture

b) Ventricular septal rupture

c) Ventricular free wall rupture

II. Arrhythmias

III. Cardiac pump failure

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Thank you very much

for listening

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active coronary syndroms

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