ECG axis: Difference between revisions

Latest revision as of 22:13, 27 March 2024

ECG Axis

Limb and augmented leads

Precordial leads

Normal Axis

-30°→90°
Dominant QRS direction (positive or negative) can be used to approximate axis
- Normal axis if positive QRS in leads I and aVF

Right Axis Deviation

Causes:
- Usually accompanied by tall R wave in V1
  - Right ventricular hypertrophy
  - Pulmonary hypertension & chronic lung disease
- COPD
- Pulmonary embolism
- Left posterior fascicular block
- Lateral MI (from Q-waves in lead I)
- Ventricular ectopy (VT)
- TCA toxicity, sodium channel blocker toxicity
- Hyperkalemia
- Lead misplacement
- Dextrocardia
- Normal thin adults with horizontally positioned hearts

Left Axis Deviation

Causes:
- Left anterior fascicular block
- Left Bundle Branch Block
- Inferior MI (from Qs)
- Left Ventricular Hypertrophy
- Pacer
- WPW
- Hyperkalemia
- Normal variant

External Links

DDxOf: ECG Guide

References

Authors:

@@ Line 1: / Line 1: @@
-*Cannot be measured if BBBs are present
+[[File:Axes.png|thumb|ECG Axis]]
-*If up in leads 1 and AVF then normal axis
+[[File:Limb_leads.png|thumb|Limb and augmented leads]]
+[[File:Precordial_leads.png|thumb|Precordial leads]]
+==Normal Axis==
+*-30°→90°
+*Dominant QRS direction (positive or negative) can be used to approximate axis
+**Normal axis if positive QRS in leads I and aVF
 ==Right Axis Deviation==
+*Causes:
+**Usually accompanied by tall R wave in V1
+***[[Right ventricular hypertrophy]]
+***[[Pulmonary hypertension]] & chronic lung disease
+**[[COPD]]
+**[[Pulmonary embolism]]
+**[[Left posterior fascicular block]]
+**Lateral MI (from Q-waves in lead I)
+**Ventricular ectopy (VT)
+**[[TCA toxicity]], sodium channel blocker toxicity
+**[[Hyperkalemia]]
+**Lead misplacement
+**Dextrocardia
+**Normal thin adults with horizontally positioned hearts
-;Causes of Rightward Axis Deviation:
+==Left Axis Deviation==
-#Right ventricular hypertrophy
+*Causes:
-#Pulmonary HTN - Acute (PE) & chronic lung disease (COPD)
+**[[Left anterior fascicular block]]
-#Left posterior fascicular block
+**[[Left Bundle Branch Block]]
-#Lateral MI (from Q-waves in lead I)
+**Inferior MI (from Qs)
-#Ventricular ectopy (VT)
+**[[Left Ventricular Hypertrophy]]
-#Hyperkalemia
+**Pacer
-#Lead misplacement
+**[[WPW]]
-#Dextrocardia
+**[[Hyperkalemia]]
-#Normal thin adults with horizontally positioned hearts
+**Normal variant
 ==See Also==
 *[[ECG (Main)]]
-[[Category:Cards]]
+==External Links==
+*[http://ddxof.com/ecg-guide/ DDxOf: ECG Guide]
+==References==
+<references/>
+[[Category:Cardiology]]