Management of Anginaand

Acute Myocardial Infarction

CLINICAL PRESENTATIONS

I. Stable angina pectoris Ischaemia due to fixed athromatous stenosis

II. Unstable angina Dynamic obstruction due to plaque

rupture and superimposed thrombosis

III. Acute Myocardial Infarction Myocardial necrosis due to acute occlusion of coronary artery

Acute Coronary Syndrome

Unstable Angina & AMI

Factors infulencing myocardial oxygen supply and demand

OXYGEN DEMAND

Cardiac work- Heart rate, blood pressure Myocardial contractility,

LV hypertrophy

OXYGEN SUPPLY

Coronary blood flow Duration of diastole

Coronary perfusion pressureCoronary vasomotor toneOxygenation- haemoglobin

oxygen saturation

Activities precipitating angina

Physical exertion

Cold exposure

heavy meals

Intense emotion

Lying flat

Vivid dreams

Risk stratification in stable angina

HIGH RISKPost infarction anginaPoor effort toleranceIschaemia at low work loadLt main or three vessel diseasePoor LV function

Low risk

Predictable exertional anginaGood effort toleranceIschaemia only at high workloadSingle or minor two vessel diseaseGood LV function

Management of Angina

Careful assessment of the likely extent and severity of arterial disease

Identification and control of significant risk factors

Use of measure to control symptoms

Identification of high risk patients and application of treatment to improve life expectancy

Advice to patient with stable angina

.Do not smoke

.Ideal body weightregular exercise.Avoid severe , unaccustomed exercise, vigorous exercise after heavy meal or in very cold weather.Sublingual nitrate before exertion that may induce angina

II. MEDICAL TREATMENT

A. Symptomatic ( prevent or relieve angina Nitrates- Sublingual / buccal GTN

Transdermal GTN Oral long acting ntrates

(isosorbide mono/dinitrates)

-Beta blockers- Atenolol 50-100 mg/d Metoprolol 25-50 mg/d

-Ca channel blocker( when beta blocker is contra-indicated or in case of coronary spasm)

Nifedipine 5- 20 mg 8 hourlyNicardipine 20-40 mg 8 hourlyAmlodipine 2.5-10 mg odDiltiazem 60-120 mg 8 hourlyVerapamil 40-80 mg 8 hourly

Potassium channel activator

Nicorandil sodium 10-30 mg 12 hourly

B. Prognostic treatment ( To improve long term prognosis and prevent coronary event )

-Asprin – 75-150 mg/d

-Other antiplatelet – Clopidogrel( if patient can not tolerate asprin) 75 mg daily

-Lipid lowering agents- Statins, Fibrates

III. SURGICAL ( INVASIVE ) TREATMENT

A. Percutaneous Coronary Intervention

-Balloon angioplasty-Implantation of coronary stent

B. Coronary Artery Bypass Graft ( CABG )

Antiplatelet ( Asprin and Clopidogrel ) and aggressive lipid lowering therapy shown to slow progression of disease in native coronary vessel and bypass graft

Comparism of PCI and CABGPCI CABG

Death 0.5% 1.5%MI 2% 10%Hospital stay 12-36 hour 5-8daysReturn to work 2-5 days 6-12weeksRecurrent angina 30% at 6 month 10% at 1 yearRecurrentrevascularisation 20% at 2 yr 2% at 2 yrNerological complication Rare common

Other complications Emergency CABG Diffuse myocardialVascular damage damage

InfectionWound pain

Management ofAcute Myocardial Infarction

DIAGNOSIS OF AMI

At least two of the followings

- History of ischaemic type of chest pain

- Evolving ECG changes

- Rise and fall of cardiac enzymes

ST Elevation Q wave

CARDIAC ENZYMES

Enzymes Peak Persist

Troponin I 2-4 hours 7 days

CKMB within 24 hours 48 hours

SGOT ( AST ) 48 hours 72 hours

LDH 72 hours 10 days

Treatment of Acute Myocardial Infarction

Acute condition

Keep in coronary care unit ( CCU ) provide facilities for defibrillation

High flow oxygen

IV access and ECG monitor for arrhythmias

Pain relief- IV morphine 10mg or diamorphine 5 mg

with metoclopramide or cyclizine

Asprin -300 mg chewed

REPERFUSION

IV thrombolysis with Streptokinase 1.5 million units over 1 hour (within 12 hour after onset of chest pain)

Other thrombolytic agents- r TPA

Urgent PTCA

As primary treatment

Failed thrombolysis

Contraindication to thrombolysis

Re infarction

Other treatments

-IV atenolol – improve survival prevent myocardial rupture

IV nitrate infusion- for persistent pain

Anticoagulants( SC heparin) in addition to oral asprin may prevent reinfarction after thrombolysis and prevent DVT and pulmonary embolism

SUBSEQUENT MANAGEMENT ( SECONDARY PREVENTION )

Oral beta blocker ( atenolol ) if LV function is good

ACEI if LV function is poor

Asprin 75-100 mg/d ay

Lipid lowering therapy

Modification of risk factor – Smoking, exercise, diet

PTAC or CABG

ACUTE COMPLICATIONS OF AMI

Cardiac arrest

Cardiac arrhythmias (especially ventricular arrhythmia )

Cardiac conduction disturbance ( heart block )

Cardiac failure- extensive myocardial infarction

Cardiogenic shock

Pericarditis

LATE COMPLICATIONS OF AMI

Recurrent angina or infarction

Thromboembolism

Mitral regurgitation – ruptured cordae tendinae/ papillary muscle dysfunction

Ventricular free wall rupture- haemopericardium

Ventricular aneurysm

Acute ventricular septal defect

Post-myocardial infarction syndrome (Dressler'ssyndrome ) Immunological reaction- fever,arthralgia,pericarditis, pericardial effusion

Recurrent arrhythmias

Shoulder hand syndrome

Psychological- depression

POOR PROGNOSTIC FACTORS

Old age

Large infarct

Poor LV function

Residual myocardial ischaemia

Ventricular arrhythmias