-30 to-90 degree axis de viatio n ind icates -
Ans. is 'a' i.e., Left Axis Deviation o The normal axis flows down and towards the left lower aspect of the heart between -36 to +90.Cardiac axiso The electrical signal recorded on the electrocardiogram (ECG) contains information relative to direction and magnitude of the various complexes.o The average direction of any of the complexes can be determined.Normal Cardiac Axiso The normal QRS electrical axis, as established in the frontal plane, is between -30 and 90deg (directed downward or inferior and to the left) in adults.Left Axis Deviationo An axis between -30deg and -90deg (directed superior and to the left) is termed left axis deviation.Right Axis Deviationo If the axis is between 90deg and 180deg (directed inferior and to the right), then right axis deviation is present.Extreme Right Axis Deviationo An axis between -90degand-180deg (directed superior and to the right) is referred to as extreme right or left axis.Indeterminateo If the QRS is equiphasic in all leads with no dominant QRS deflection, it is indeterminate axis.Causes of axis deviation include||Right axis deviationLeft axis deviationo Normal variation (vertical heart with an axis of 90deg)o Normal variation (physiologic, often with age)o Mechanical shifts, such as inspiration and emphysemao Mechanical shifts, such as expiration, high diaphragm (pregnancy, ascites, abdominal tumor)o Right ventricular hypertrophyo Right bundle branch blocko Left ventricular hypertrophyo Left posterior fascicular blocko Left bundle branch blocko Dextrocardiao Left anterior fascicular blocko Ventricular ectopic rhythmso Congenital heart disease (primum atrial septal defect, endocardial cushion defect)o Pre-excitation syndrome (Wo iff Pa rki ns on- White)o Lateral wall myocardial infarctiono Emphysemao Secundum atrial septal defecto Hyperkalemia o Ventricular ectopic rhythms o Pre-excitation syndromes (Wolff-Parkinson-White) o Inferior wall myocardial infarction.
Left Axis Deviation
Right Axis Deviation
Extrene Right .Axis Deviation
Normal Cardiac Axis
Electrocardiography