What is the cardiac axis?
Table of Contents
Cardiac axis represents the sum of depolarisation vectors generated by individual cardiac myocytes. Clinically is is reflected by the ventricular axis, and interpretation relies on determining the relationship between the QRS axis and limb leads of the ECG (below diagram)
Is right axis deviation life threatening?
Although not a dangerous finding in and of itself, axis deviation may be an indication of a serious underlying condition.
What does vertical axis on EKG mean?
With an electrically vertical mean QRS axis, leads II, III, and aVF show tall R waves. With an electrically horizontal mean QRS axis, leads I and aVL show tall R waves. With an electrically vertical heart, the actual mean QRS axis may be normal (e.g., +80°) or abnormally rightward (e.g., +120°).
WHY is aVL positive?
aVR means augmented Vector Right; the positive electrode is on the right shoulder. aVL means augmented Vector Left; the positive electrode is on the left shoulder.
How serious is left axis deviation?
In conclusion, among patients with left bundle branch block, those with left axis deviation have a greater incidence of myocardial dysfunction, more advanced conduction desease and greater cardiovascular mortality than those with a normal axis.
What causes heart axis deviation?
Some of the causes include normal variation, thickened left ventricle, conduction defects, inferior wall myocardial infarction, pre-excitation syndrome, ventricular ectopic rhythms, congenital heart disease, high potassium levels, emphysema, mechanical shift, and paced rhythm.
Why is aVR inverted?
There are three advantages of inverting aVR into –aVR: –aVR fills the gap between lead I and lead II in the coordinate system. –aVR facilitates calculation of the hearts electrical axis. –aVR improves diagnosis of acute ischemia/infarction (inferior and lateral ischemia/infarction).
What is the normal direction of the cardiac axis?
Since the left ventricle makes up most of the heart muscle under normal circumstances, normal cardiac axis is directed downward and slightly to the left: Normal Axis = QRS axis between -30° and +90°.
What is cardiac axis in ECG?
Cardiac axis represents the sum of depolarisation vectors generated by individual cardiac myocytes. Clinically is is reflected by the ventricular axis, and interpretation relies on determining the relationship between the QRS axis and limb leads of the ECG (below diagram)
What is the axis of a positive QRS in lead AVF?
A positive QRS in Lead aVF similarly aligns the axis with lead aVF. Combining both coloured areas – the quadrant of overlap determines the axis. So If Lead I and aVF are both positive, the axis is between 0° and +90° (i.e. normal axis). Note: **Possible LAD can be further evaluated using Lead II as detailed in method 2 below…
Are there any good ECG axis videos on YouTube?
Here is the first of five great YouTube videos on ECG Axis: And here are some screen shots from the above video: This entry was posted in Cardiology, ECG, Electrocardiography, Emergency Medical Services, Emergency Medicine.