Pericarditis electrocardiogram

Overview
The typical EKG finding in acute pericarditis is ST segment elevation in leads I, II, aVL, aVF, and V3-V6. Low-voltage QRS complex may be observed in large pericardial effusion and constrictive pericarditis. Cardiac tamponade is characterized by electrical alternans.

Key EKG Findings in Pericarditis
Typical lead involvement: I, II, aVL, aVF, and V3-V6.

The ST segment is always depressed in aVR, frequently in V1, and occasionally in V2. Occasionally, stage IV does not occur and there are permanent T wave inversions and flattenings. PR segment depression may be observed in this stage in leads other than aVR. This is known as 'Spodick's sign'.

If EKG is first recorded in stage III, pericarditis cannot be differentiated by EKG from diffuse myocardial injury, "biventricular strain," or myocarditis.

EKG in early repolarization is very similar to stage I. Unlike stage I, this EKG does not acutely evolve and J point elevations are usually accompanied by a slur, oscillation, or notch at the end of the QRS just before and including the J point (best seen with tall R and T waves – large in early repolarisation pattern).

Pericarditis is likely if in lead V6 the J point is >25% of the height of the T wave apex (using the PR segment as a baseline). Increase in scar tissue, fluid and fibrin can reduce voltage, quasi-specific ST-T waves can present. The EKG abnormalities vary depending on the stage/severity of the pericarditis. Below are the stages/types of pericarditis:


 * 1) Acute Pericarditis (see also Electrocardiography and Electrocardiography): this variation of the disease in conjunction with myocarditis can lead to ST-T anomalies that are characteristic of the acute stages of pericarditis.
 * 2) *Stage 1: Stage 1 of acute pericarditis, in and of itself, presents as "early repolarization" and acute infarction. It shows signs of anterior and inferior ST elevation on the EKG.  There are usually no deviations in the QRS complex.  This stage is largely characteristic of acute pericarditis when almost all of the leads are effected.  Leads I, II, avL, avF, and V3-V6.
 * 3) *Stage 2: During the early phase of this stage, ST segments should become baseline again; whereas, PR segments may have deviated. During the latter phase of stage 2, the ST segments that were previously elvated usually flatten and invert.
 * 4) *Stage 3: Virtually all of the leads in stage 3 exhibit T wave inversion. Acute pericarditis cannot be diagnosed on an ECG of a stage 3 patient because its presentation is the same as myocardial injury and frank myocarditis.
 * 5) *Stage 4: This stage presents itself on the EKG as a return to a prepericarditis state. Stage 4 does not always occur and in its absence, there can be residual T wave inversions that may be permanent, generalized or focal.
 * 6) Rate and Rhythm: Rapid heart rates are typical in patients with pericarditis, but in patients with uremic pericarditis slower rates are observed. Heart rhythms appear normal unless there is another complication such as cardiac disease, the presence of myocardial/pericardial tumor, or a metabolic disorder.
 * 7) Pericardial Effusion (see also Electrocardiography): These can present differently on the EKG depending on whether they are chronic vs large effusions. The former typically leads to low amplitude EKGs; whereas, the latter can show no voltage or various ECG abnormalities.  ST-T wave abnormalities can be caused by superficial myocarditis or because of the accumulated fluid, they may be caused by the compression of the myocardium or ischemia.  The primary cause of ST segment variation during pericardial effusions is usually the rapid accumulation of fluid.  Large effusions can lead to the reduction of P wave voltage.  Pleural effusions can cause a decrease in voltage, which occurs mainly on the left.  Also, cirrhosis and congestive heart failure (CHF), which similarily involve the accumulation of fluid in the body, can decrease voltage in the absence of any pericardial disease.
 * 8) Cardiac tamponade (see also Cardiac tamponade): Generally has little EKG effect; however, in the acute form, tamponade may present on the EKG as any one of the stages of acute pericarditis.
 * 9) Electrical Alternation: This occurs more often in cases of tamponade than in those of pericarditis (2:1). There is alternation of the QRS complex on the spatial axis.  Alternation of the T wave, P wave, and PR segement are difficult to see and are uncommon.  The removal of even a small amount of fluid can end alternation.
 * 10) Early Repolarization: This finding can be misleading and may look like pericarditis, when in fact it is not. A strong indication of pericarditis is "if the J point is more than 25% the height of the T wave apex."
 * 11) Constrictive Pericarditis: Cases of constrictive pericarditis have nonspecific EKG abnormalities. Common abnormalities include: a slightly "low voltage QRS" segment combined with "flattened to inverted T waves", during stage 3 of acute/subacute constriction the T wave inversions remain or worsen and "P waves can be wide and bifid."  It is not uncommon for patients to have normal EKGs.  Many patients may only exhibit "nonspecific T wave abnormality."  Other influencial factors that may effect the EKG in constrictive pericarditis are: fluid retention, ascites, and pleural effusions.  The two most common arrhythmias that occur are atrial fibrillation and atrial flutter.
 * 12) *QRS Abnormality: characteristic RV hypertrophy QRS abnormalities may develop as a result of disproportionate constriction or postpericardiectomy scarring. Also, "focal atrophy, scarring or inflamation" may cause "abnormal Q waves."
 * 13) **Chronic Constrictive Pericarditis: low volatage and myocardial atrophy, "frontal QRS axis" is usually vertical (becomes more vertical with increasing chronicity),
 * 14) **Acute/Subacute Pericarditis: QRS axis appears as normal

EKG Examples of Pericarditis