Ischemic Heart Disease

The standard 12-lead ECG is central to confirming the diagnosis. The initial ECG may be normal or non-diagnostic in one-third of cases. Repeated ECGs are important, especially where the diagnosis is uncertain or the patient has recurrent or persistent symptoms. The earliest ECG change is usually ST-segment deviation.

ST elevation may signify myocardial infarction, pericarditis or left ventricular aneurysm
ST depression may signify ischaemia or infarction

Angina pectoris is a symptom complex caused by transient myocardial ischaemia, which occurs whenever there is an imbalance between myocardial oxygen supply and demand. Coronary atherosclerosis is by far the most common cause of angina pectoris

There is a strong relationship between cigarette smoking and CAD, especially in younger (< 70 years) individuals, and this is the most important modifiable risk factor.

Troponin I and troponin T are structural cardiac muscle proteins that are released during myocyte damage and necrosis, and represent the cornerstone of the diagnosis of acute myocardial infarction

Ref: Davidson P-393

Chest pain at rest is the cardinal symptom of MI but breathlessness, vomiting and collapse are also common features. Painless or ‘silent’ MI may also occur and is particularly common in older patients or those with diabetes mellitus