![]() In contrast to that, left axis deviation (LAD) is defined as QRS axis between −30° and −90°, and right axis deviation is defined as QRS axis greater than +90°, while extreme axis deviation occurs when QRS axis is between -90° and 180°. In a normal axis, QRS is between -30° and +90°. Usually, left ventricles makes up most of the heart muscles, so a normal cardiac axis is directed downward and slightly to the left. To interpret the cardiac axis, one has to determine the relationship between the QRS axis and limb leads of the ECG. Symptoms and treatment of left axis deviation depend on the underlying cause.Ĭardiac axis in electrocardiography represents the sum of depolarization vectors generated by individual cardiac myocytes. 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. There are several potential causes of LAD. This is reflected by a QRS complex positive in lead I and negative in leads aVF and II. In electrocardiography, left axis deviation (LAD) is a condition wherein the mean electrical axis of ventricular contraction of the heart lies in a frontal plane direction between −30° and −90°. ![]() The hexaxial reference system is a diagram that is used to determine the heart's electrical axis in the frontal plane.
0 Comments
Leave a Reply. |