Acute pericarditis

See brief interpretation of 12 lead EKG above

- ST segment elevation bulging downwards in both precordial and inferior leads
- indication of slight PR depression in V5 and V6
- this case is difficult to distinguish from acute inferior myocardial infarction due to apparently more localized ST segment elevations in the inferior leads (II, III, aVF): a coronary angiography was normal and there was no elevated cardiac enzyme levels in the blood tests

The EKG findings in acute pericarditis consist of diffuse ST segment elevation and sometimes depression of the PR interval. The ST segment changes may mimic those seen in acute myocardial infarction. However, the ST segment elevation in pericarditis differs in two ways:

1) It is usually diffusely present in most leads. In acute myocardial infarction the ST segment elevation is localized to a few leads corresponding to a coronary vascular area.
2) It bulges downward. This is sometimes referred to as a “hammock”-like appearance. In acute myocardial infarction the ST segment elevation bulges upward.

Also pathological Q wave formation are absent in pericarditis.

The EKG changes in pericarditis likely occur due to affection of the subepicardiel layers of the ventricles (diffuse ST segment elevation) as well as the atria (PR segment depression).

Pericarditis may have viral, autoimmune, neoplastic, uremic or bacterial causes. It is associated with chest pain and a pericardial rub upon auscultation.

– Mathias