Various diseases and ECG criteria

 

The following are some heart diseases, with their most significant ECG criteria.

The sense of these notes is to be able to identify a disease beyond the clinic, by the only electrocardiographic signals.

 

Anterior subendocardial Ischemia

- T waves high and negative on I, II, aVL, V5, V6

 

Acute pulmonary embolism

- S wave in I, aVL

- Q in III

- T neg in III, aVF

- Complete or incomplete RBBB

- Low Voltage on Lead limbs

 

Atrial septal defect (ASD)

Right ventricular overload with:

- Complete or incomplete Right bundle branch block (RBBB)

- Right Axis Deviation

 

Apex Myocardial Infarction

- Q wave in I, II, III

 

Anteroseptal myocardial Infarction

- ST above + Q waves in V1-3

- T neg. in V1, 2, aVL

 

Anterior myocardial infarction

ST elevation in V2, 3.4

 

Anterior/Left Myocardial Infarction

- ST elevation and (maybe) Q waves in V4-6

 

Biatrial hypertrophy

- Leads I and II have an early, pointed, and bifid P.

- V1 observe in the first half 'of diphasic P' right atrial hypertrophy associated with subsequent significant negativity  of the left atrial hypertrophy

 

Dextrocardia (or inversion of limb leads)

- P neg.in I

- P pos. in II, III

 

Digitalis effect

- Depression of the ST segment in V4

 

Hyperkalaemia

Potassium> 5.5:

- T wave high and pointed in V3, 4.5

- Slightly widened QRS

Potassium> 6.5:

- !st degree AV Block

- ST depression

- Wide QRS

- P waves barely visible, flat.

Potassium> 7.5:

- P waves are absent

- RBBB, LBBB, Ventricular Tachycardia, Ventricular Fibrillation, asystole.

 

Hypercalcemia.

- Shortened QT interval (V2)

- J Wave

 

Hypokalemia

- ST segment depression

- Flattening of the T wave

- Appearance of U wave in V3-6

- Supraventricular tachycardia

- Atrial ectopic beats

 

Hypocalcemia.

- Prolonged QT interval (II, 0.52 sec.)

 

Inferior Myocardial Infarction

- ST elevation in II, III, aVF

- ST depression in I, aVL and precordial leads.

 

Juvenile type ECG (max 30 years)

- T wave inverted (negative) in V1, V2, V3, V4.

- ST-segment elevation

- Tall T-wave.

 

Left atrial hypertrophy (LAH)

("mitral P wave" because the disease is present in the case of mitral stenosis).

- P waves wide (> 120 ms) and bifid in I

- Bifid P wave in V1 very deep negative

 

Left Axis Deviation

- Typical in old people, obesity

- Left anterior fascicular block

- 50% Left ventricular hypertrophy (LVH)

 

Left high Myocardial infarction

- ST elevation in I, aVL

 

Left Myocardial infarction.

- St segment elevation and (maybe) Q waves in I, aVL, V5, V6

 

Left ventricular hypertrophy (LVH)

- Left Axis Deviation

- R> 25 mm (5 squares) in V5 or V6

- S> 25 mm (5 squares) in V1 or V2

- left atrial Hypertrophy

- ST-segment depression (I, V5, V6) and negative T wave

Sokolow-Lyon index:

- SV1 + (RV5 or RV6)> 3.5 mV

- R in aVL> 1.1 mV

Cornell voltage criteria

S wave in V3 + S wave in aVL ≥ 2.8 mV (for men)

S wave in V3 + S wave in aVL ≥ 2.0 mV (for women)

 

Low voltage in all leads.

- Are observed in the case of obesity, exudative pericarditis, Myocardial infarction, Chronic obstructive pulmonary disease (COPD) or old people.

 

Old inferior infarction (diaphragmatic)

- Q wave in II, III, aVF

- T waves neg. and deep

- ST isoelectric (normal)

 

Posterior Infarction

- High R waves on V1-V3

 

Pericarditis

Acute phase:

- ST segment elevation in all leads

Subacute-chronic:

- negative T (No ST)

Low voltage in case of massive effusion or constrictive forms.

 

Right Axis Deviation

- Typical in young and lean people.

- Sudden onset of Right Axis Deviation could be embolism or pulmonary infarction.

- left posterior fascicular block (LPFB)

 

Right myocardial infarction

- ST elevation in V1-3

 

Right atrial hypertrophy (RAH)

(Right atrial overload by tricuspid stenosis or pulmonary hypertension).

- P waves high (> 2.5 mm) and pointed in II, III, aVF, V1

 

Right ventricular hypertrophy: (RVH)

Right-Axial Deviation

-QRS negative in I

-QRS positive in V1

-ST-segment abnormalities in V3-V1-aVF-I (QRS-T angle very large (> 60)

 

Subendocardial ischemia

- High T Positive wave in the ischemic zone

 

Subepicardial ischemia

- neg. deep and symmetrical T in the ischemic zone

- T and QT normal or slightly elongated

 

Ventricular Aneurysm

- ST segment elevation in V2

- Inverted T wave in V2