CCT Exam Practice - Interpreting a 12-Lead
ECG & MI's UPDATED ACTUAL Exam
Questions and CORRECT Answers
axis deviation - CORRECT ANSWER - current travels in an abnormal direction
how is axis determined? - CORRECT ANSWER - by examining lead I and lead AVF
normal axis - CORRECT ANSWER - between 0 and +90
lead I: +QRS deflection
lead AVF: +QRS deflection
right axis deviation - CORRECT ANSWER - between +90 and +180
lead I: -QRS deflection
lead AVF: +QRS deflection
extreme right axis deviation - CORRECT ANSWER - between -90 and -180
lead I: -QRS deflection
lead AVF: -QRS deflection
left axis deviation - CORRECT ANSWER - between -30 and -90
lead I: +QRS deflection
lead AVF: -QRS deflection
mnemonic for axis deviations - CORRECT ANSWER - thumbs up method:
lead I = left thumb
AVF = right thumb
, left thumb up (I) & right thumb up (AVF) = normal
left thumb up (I) & right thumb down (AVF) = left axis deviation
left thumb down (I) & right thumb up (AVF) = right axis deviation
bundle branch block - CORRECT ANSWER - impulse is delayed or blocked within the
bundle branches of the normal conduction pathway
- results in widened QRS >=0.12 secs (about 3 blocks or more) with characteristic QRS shape
RBBB characteristics - CORRECT ANSWER - QRS >=0.12 secs
RSR' configuration in V1 (or V2-3)
widened, deep S waves in lateral leads (leads I, AVL, V5-6)
T wave slopes opposite terminal wave of QRS
LBBB characteristics - CORRECT ANSWER - QRS >=0.12 secs
wide QS or rS (small R deep S) configuration in V1 (or V2-3)
broad R waves in lateral leads (leads I, AVL, 5-6)
T wave slopes opposite terminal wave of QRS
low voltage EKG - CORRECT ANSWER - abnormally short waves and complexes
occurs due to obesity or emphysema
ventricular hypertrophy - CORRECT ANSWER - - excessive growth of ventricular
myocardium in the affected ventricle
- causes greater than normal amplitude of QRS
right ventricular hypertrophy (RVH) criteria - CORRECT ANSWER - R wave dominance
over S wave in V1-V2
S wave dominance over R wave in V6
T wave inversion (not an absolute requirement) in V1-V2
ECG & MI's UPDATED ACTUAL Exam
Questions and CORRECT Answers
axis deviation - CORRECT ANSWER - current travels in an abnormal direction
how is axis determined? - CORRECT ANSWER - by examining lead I and lead AVF
normal axis - CORRECT ANSWER - between 0 and +90
lead I: +QRS deflection
lead AVF: +QRS deflection
right axis deviation - CORRECT ANSWER - between +90 and +180
lead I: -QRS deflection
lead AVF: +QRS deflection
extreme right axis deviation - CORRECT ANSWER - between -90 and -180
lead I: -QRS deflection
lead AVF: -QRS deflection
left axis deviation - CORRECT ANSWER - between -30 and -90
lead I: +QRS deflection
lead AVF: -QRS deflection
mnemonic for axis deviations - CORRECT ANSWER - thumbs up method:
lead I = left thumb
AVF = right thumb
, left thumb up (I) & right thumb up (AVF) = normal
left thumb up (I) & right thumb down (AVF) = left axis deviation
left thumb down (I) & right thumb up (AVF) = right axis deviation
bundle branch block - CORRECT ANSWER - impulse is delayed or blocked within the
bundle branches of the normal conduction pathway
- results in widened QRS >=0.12 secs (about 3 blocks or more) with characteristic QRS shape
RBBB characteristics - CORRECT ANSWER - QRS >=0.12 secs
RSR' configuration in V1 (or V2-3)
widened, deep S waves in lateral leads (leads I, AVL, V5-6)
T wave slopes opposite terminal wave of QRS
LBBB characteristics - CORRECT ANSWER - QRS >=0.12 secs
wide QS or rS (small R deep S) configuration in V1 (or V2-3)
broad R waves in lateral leads (leads I, AVL, 5-6)
T wave slopes opposite terminal wave of QRS
low voltage EKG - CORRECT ANSWER - abnormally short waves and complexes
occurs due to obesity or emphysema
ventricular hypertrophy - CORRECT ANSWER - - excessive growth of ventricular
myocardium in the affected ventricle
- causes greater than normal amplitude of QRS
right ventricular hypertrophy (RVH) criteria - CORRECT ANSWER - R wave dominance
over S wave in V1-V2
S wave dominance over R wave in V6
T wave inversion (not an absolute requirement) in V1-V2
