Cardiac disease

CARDIAC DISEASE CLINICAL BIOCHEMISTRY

Learning Objectives
Explain the etiology of Myocardial infarction (MI).
List out the symptoms of MI.
Elaborate the tests to investigate the disease.

Myocardial Infarction
Heart attack= MI= death of heart muscle from the sudden blockage of a coronary artery by blood clot
Blockage; injury; chest pain & pressure; muscle death; scar tissue.

Etiology
Atherosclerosis with occlusive or partially occlusive thrombus formation

Symptoms of MI
1) Chest pain
Squeezing, aching, burning or sharp pain
More than 30 min: infarction
Associated with nausea, vomiting, dyspnea,
fatigue or palpitations
Atypical chest pain common in diabetes and
elderly patients

2) Shortness of breath
Anginal equivalent or symptom of heart failure
Due to elevated end-diastolic pressure; lead to elevated pulmonary pressure

3) Atypical presentations
Common and lead to misdiagnoses
Abdominal discomfort or jaw pain may present
Elderly patient may present with altered mental status
Women present more common atypical symptoms

Physical Examination of MI
Low grade fever
Hypo or hypertension
4 th heart sound (S4) may be heard
Dyskinetic cardiac bulge
Systolic murmur can be heard
Cool, clammy skin and diaphoresis
Signs of CHF

Risk Factors
1) Non modifiable risk factors
Family history of premature coronary heart disease

2) Modifiable risk factors
Smoking
Diabetes mellitus
Hypertension
Dyslipidemia
Obesity
Sedentary life
Psychosocial stress
Poor oral hygiene

3) Non atherosclerotic causes
Vasculitis
Coronary emboli
Congenital coronary anomalies
Coronary trauma
Coronary spasm
Drugs
Factors that increase O2 requirement & decrease O2 delivery

Lab Investigation
Cardiac enzymes
Troponin levels
Myoglobin levels
Lipid profile
ECG

Cardiac Enzymes
Creatine kinase: 3 isoenzymes
CK-MB: mainly in heart
Serial measurement of CK-MB for diagnosis MI
CK-MB: increase within 3-12 hours of onset, peak values within 24 hours, return baseline after 48-72 hours
High sensitivity & specificity (but not as high as Trop T)

Troponin
Greater sensitivity & specificity
Role in diagnostic and prognostic
Positive troponin levels virtually diagnostic of MI
Trop T: increase within 3-12 hours from onset, peak at 24-48 hours, return baseline over 5-14 days

Myoglobin
Urine myoglobin: rise within 1-4 hours from onset
High sensitive but not specific
Useful in early detection of MI in the ED

Treatment of MI
Restoration balance between oxygen supply and demand
Pain relief
Prevent and treat complications

QUESTIONS :
Discuss in a group;
(1) Information about Myocardial infarction.
Discussion must include the etiology, symptoms, physical examination and risk factor.
(2) Elaborate the tests to investigate the disease.

Thank You

Cardiac disease

by Xànédîa FiFi

Accessibility

Categories

Upload Details

Usage Rights

Statistics

Cardiac disease Presentation Transcript