7. Disease
        Cardiovascular
Acute coronary syndrome

Acute coronary syndrome

A. Presentation

Symptoms

Signs

Medical emergency if history of:

B. Investigation

Baseline tests

Other tests

Coronary angiography

- for all high risk and selected intermediate risk patients.

Stress exercise tests (stress radionuclide or stress echocardiography or exercise ECG)

- for intermediate patients who has had normal baseline ECG and normal troponin at baseline and 6 hours.

C. Treatment

Initial management of all patients

Rest and take aspirin 300mg

Also take a short acting nitrate (e.g. glyceryl trinitrate)

Pain relief with morphine

Early management of all patients

If chest pain persist, move to high risk patient management.

If chest pain disappears, perform risk stratification.

Management of low risk patient

Be referred for cardiac assessment within 2 weeks.

Patient should be given aspirin and beta-blockers.

If beta-blocker is contraindicated

--> diltiazem or verapamil (Non-dihydropyridin calcium channel blockers) instead

(but never together with beta-blocker)

Patient should be provided with buccal nitroglycerine and instructed in its use.

Management of intermediate risk patient

Observation of at least 6-8 hours, during which they would be reclassified into either low or high risk and manage accordingly.

If troponin was still normal at 6 hours, do stress test to reclassify.

If troponin was elevated or abnormal stress test -> Patient becomes high risk, otherwise low risk.

Management of high risk patient (unstable angina or MI)

Acute medical management

If chest pain persist with the above 3 medication:

Invasive procedure (all high risk patient)

Plan in very near future:

Reperfusion therapy

Includes thrombolytic therapy and emergency invasive procedure.

Long term management of all patients

All patients with a diagnosis of unstable angina or myocardial infarction should be referred to an appropriate cardiac rehabilitation and prevention program, as well as to the GP for counselling and risk factor management.

Management of stable angina

Calcium channel blocker

If beta-blocker is not enough, add a dihydropyridine calcium channel blocker (e.g. amlodipine, felodipine).

If beta-blocker is contraindicated (and thus not used), substitute a long-acting non-dihydropyridine calcium channel blocker (e.g. diltiazem, verapamil).

NB: Tolerance to all forms of nitrate therapy develops rapidly. Allow a nitrate-free period. (e.g. patches worn for less than 16 hours per day).

D. Other notes

[epidemilogy/risk factors/
causes/mechanisms/compications/ddx/
classification/staging/
followups/prognosis/prognostic factors/prevention]

Simplified risk-assessment algorithm

Pain, but not at rest, repetitive, prolonged, and no ECG or troponin changes

---> low risk

---> <2% 6-month risk of death from MI

Pain at rest, repetitive, or prolonged, but no ECG or troponin changes

---> intermediate risk

---> 2-10% 6-month risk of death from MI

Pain at rest, repetitive, or prolonged, AND ECG or troponin changes

---> high risk

---> >10% 6 month risk of death from MI

Risk stratification of unstable angina

Very high risk features

High risk features

Intermediate risk features

Low risk features

Q wave vs non-Q wave

Traditionally the distinction between Q wave (transmural) and non-Q wave (subendocardial) infarction are made.

Q wave infarction has been proven to benefit from thrombolytic therapy while non-Q wave infarction has not.

Q waves may take days to develop.

Non-Q wave infarct is management as per unstable angina.

ST depression of 1mm and 0.5mm have the same prognostic value.

 

 

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Created20031018
Updated20031018


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