Precordial Axis Frontal Plane Axis Precordial Axis ERAD Right Axis Pathological Early Transition Late Transition Deviation Left Axis Counterclockwise Clockwise -90 to 180 90 to 180 Deviation Rotation Rotation -30 to -90• Ventricular • May be normal • Pregnancy • Posterior wall • SometimesRhythm • LPFB • LAFB infarction Normal,• Paced • Pulmonary • WPW • RVH especially inRhythm disease • RBBB women • Pulmonary• Dextrocardia • RVH disease • WPW • Anterior MI• Electrolyte • RBBB • LBBB • LVHderangement • WPW • Hyperkalemia • LAFB • Dextrocardia • Q-waves, MI • LBBB •Venrticular • Lung Disease Rhythm
Precordial AxisAxis Determination Normal R-wave progression Thompson 93ECG - 20ECG – 20This is a rare example of an isolated Lateral Wall Infarct. This injury pattern is nearly always due to an occlusion to the LeftCircumflex (LCx). 5 Easy Steps
Precordial AxisAxis Determination Thompson 100 Early R-wave progressionECG – 26ECG – 26This ECG is an example of Right Bundle Branch Block (RBBB). RBBB is presentwhen a wide supraventricular rhythm presents with a positive terminal deflection in V1.Other findings include appropriate T-wave discordance, and a slurred S-wave in Lead I
Precordial AxisAxis Determination Late R-wave progression Thompson 90ECG – 17ECG – 17This is an example of an Antero-Septal MI, with some lateral wall extension. This is likely due to a proximal occlusion of the LeftAnterior Descending coronary artery (LAD). The LAD, termed ―Widow Maker‖, supplies predominately the left ventricle.