ECG Interpretation Final Exam Review

ECG Interpretation Final Exam Review HEXAXIAL SYSTEM 0= - LEAD I HEXAXIAL SYSTEM +60= - LEAD II HEXAXIAL SYSTEM +120= - LEAD III HEXAXIAL SYSTEM -30= - LEAD AVL HEXAXIAL SYSTEM -90= - LEAD AVF HEXAXIAL SYSTEM -150= - LEAD AVR R WAVE TRANSITION EARLY - V1, V2 MORE VERTICAL ORIENTATION R WAVE TRANSITION LATE - V5, V6 MORE HORIZONTAL ORIENTATION QRS AXIS RIGHT AXIS DEVIATION - FROM +105--+/-180 QRS AXIS LEFT AXIS DEVIATION - FROM -90---30 QRS AXIS INDETERMINATE - ALL LEADS ARE BIPHASIC AUGMENTED LEADS UNIPOLAR - AVL AVF AVR BIPOLAR EXTREMITY LEADS - I II III PRECORDIAL/CHEST LEADS UNIPOLAR - V1 V2 V3 V4 V5 V6 ECG PAPER CALIBRATION CAN BE NORMAL, HALF OR DOUBLE - 10 MM 25MM/SEC SINUS ARRYTHMIAS - ORIGINATES IN SINUS NODE AND DISCHARGES IRREGULARLY 6 SEC METHOD FOR CALCULATING ARRYTHMIAS - COUNT WITHIN LARGE BLACK DASHES COUNT # OF R-WAVES PRESENT X10 SINUS BLOCK - BASIC RHYTHM RESUMES AFTER PAUSE (R-R) SINUS ARREST - BASIC RHYTHM DOES NOT RESUME AFTER PAUSE CARDIAC ENLARGEMENT IS DUE TO: HYPERTROPHY - PRESSURE OVERLOAD CARDIAC ENLARGEMENT IS DUE TO: DILATION - VOLUME OVERLOAD HYPERTROPHY RIGHT ATRIAL - ELEVATION 2.5MM LEAD I,II,AVF HYPERTROPHY LEFT ATRIAL - DEEPLY INVERTED V1 NOTCHED HYPERTROPHY LEFT VENTRICULAR 1 - R LEAD + S LEAD III /=25MM HYPERTROPHY LEFT VENTRICULAR 2 - S LEAD V1 + R LEAD V5/V6 /=35MM HYPERTROPHY LEFT VENTRICULAR 3 - ST & WAVE DEVIATION HYPERTROPHY LEFT VENTRICULAR 4 - LEFT AXIS DEVIATION HYPERTROPHY RIGHT VENTRICULAR - V1 IS POSITIVE R-WAVE 7MM DEPOLARIZATION - ELECTRICAL IMPULSE INTITIATES, CELL IS + CHARGED REPOLARIZATION - CELL RETURNS TO NORMAL NEGATIVITY PR INTERVAL TIMING (NORMAL) - .12-.20 SECONDS QRS COMPLEX TIMING (NORMAL) - .04-.12 SECONDS MECHANISMS OF ATRIAL ARRHYTHMIAS - 1. ALTERED