Note: mean QRS Vector & Vent Hypertrophy Can't be accurately calculated in the presence of B.B.B. Consider Causes: - HTN - Pulmonary Stenosis - Primary Pulmonary HTN - Long standing CAD - Congenital heart dz: Endocard. Cush Def/Ost. Primum Def Atrial Septal Defect Tetralogy of Fallot / Note: large R wave in V1; / small ? " " ? / R wave will get progressively smaller in V2,3,4; __/ __ there may also be Rt Axis Deviation __/ Note: Ventricular Strain causes a depressed ST segment which curves upward in the middle of the segment; - Criteria: Tall R wave in V1 (R wave > S wave in V1) Persistent S waves in V5 and V6; Progressively smaller R wave from V1 to V6 Slightly enlarged QRS intervals Strain pattern w/ ST seg. depression & [T inversion in V1 to V3; Right Ventricular Strain Pattern: (As from Massive PE): - S1, Q3, Rt Axis Deviation and RBBB; / Note: large R wave in V1; / small ? " " ? / R wave will get progressively smaller in V2,3,4; __/ __ there may also be Rt Axis Deviation __/ Note: Ventricular Strain causes a depressed ST segment which curves upward in the middle of the segment;
