ECG- interpretation UPDATED ACTUAL
Exam Questions and CORRECT Answers
Normal PR segment length - CORRECT ANSWER - 0.12 - 0.2 sec
3 - 5 small boxes
Normal QRS interval - CORRECT ANSWER - 0.06 - 0.1 sec
1 - 3 small boxes
Normal QT interval - CORRECT ANSWER - 40% of cardiac cycle
Normal P amplitude & duration - CORRECT ANSWER - < 0.12 sec (3 small boxes)
< 0.25 mV (2.5 small boxes)
Positive P waves in? - CORRECT ANSWER - left lateral (I, aVL, V5, V6) & inferior (II,
III, aVF); usually most positive in II
& most negative in aVR
Often biphasic P in? - CORRECT ANSWER - III, V1
Tall R waves in? - CORRECT ANSWER - left lateral (I, aVL, V5, V6) & inferior (II, III,
aVF)
Q waves in? - CORRECT ANSWER - in one or several of left lateral leads (I, aVL, V5,
V6), sometimes in inferior leads (II, III, aVF)
T wave positive in? - CORRECT ANSWER - Usually in leads w/ tall R waves; left lateral
(I, aVL, V5, V6) & inferior (II, III, aVF)
,R atrium enlargement? - CORRECT ANSWER - Leads II (parallel) & V1 (perpendicular;
biphasic)
1) P wave > 0.25 mV in II, III, aVF
aka "p pulmonale"
p pulmonale? - CORRECT ANSWER - RA enlargement, almost always related to
pulmonary system; usually causes backup into the ventricle & atria, causing enlargement of atria
L atrium enlargement? - CORRECT ANSWER - 1) V1 terminal portion, P > 1mm below
line
2) Terminal portion of P > 0.04 sec (1 small box)
"p mitrale"
p mitrale - CORRECT ANSWER - LA enlargement due to mitral valve issue
RVH - criteria - CORRECT ANSWER - 1) R > S in V1
2) R progressively smaller from V1-V6
3) S > R in V6
- will cause right axis deviation
(also tall R in III)
LVH - precordial criteria - CORRECT ANSWER - 1. V5: R > 26 mm
2. V6: R > 18 mm
**3. S (V1 or V2) + R (V5 or V6) > 35 mm (best)
4. V6 R > V5 R
axis is not a great indicator (L axis shift)
Sensitivity is low, specificity is high
LVH - limb criteria - CORRECT ANSWER - 1. aVL: R > 13 mm
, 2. aVF: R > 21 mm
3. I: R > 14 mm
4. R (I) + S (III) > 25 mm
2º repolarization in ventricular hypertrophy - criteria? - CORRECT ANSWER - 1. Down-
sloping ST segment depression
2. T wave inversion (R +, T -)
Tends to be most evident in leads most affected by size change
RVH = V1, V2
LVH = V5, V6
causes of arrhythmias - CORRECT ANSWER - HISDEBS: hypoxia, ischemia/irritability,
SNS, drugs, electrolytes, bradycardia, stretch (hypertrophy/enlargement)
symptoms of arrhythmias - CORRECT ANSWER - none, "palpitations," light-headedness,
syncope, angina, HF, sudden death
Types of arrhythmias - CORRECT ANSWER - 1. Sinus origin
2. Ectopic
3. Re-entrant (abnormally shaped path)
4. Conduction blocks (blocked signal)
5. Pre-excitation (shortcut in pathway)
Arrhythmias - 4 quick questions - CORRECT ANSWER - 1. Normal P waves?
2. Wide QRS? (> 0.12 sec indicates pacemaker below Bundle of His)
3. One P for every QRS?
4. Normal rate & rhythym?
Sinus arrhythmia - CORRECT ANSWER - Appearance is ALMOST NORMAL:
Exam Questions and CORRECT Answers
Normal PR segment length - CORRECT ANSWER - 0.12 - 0.2 sec
3 - 5 small boxes
Normal QRS interval - CORRECT ANSWER - 0.06 - 0.1 sec
1 - 3 small boxes
Normal QT interval - CORRECT ANSWER - 40% of cardiac cycle
Normal P amplitude & duration - CORRECT ANSWER - < 0.12 sec (3 small boxes)
< 0.25 mV (2.5 small boxes)
Positive P waves in? - CORRECT ANSWER - left lateral (I, aVL, V5, V6) & inferior (II,
III, aVF); usually most positive in II
& most negative in aVR
Often biphasic P in? - CORRECT ANSWER - III, V1
Tall R waves in? - CORRECT ANSWER - left lateral (I, aVL, V5, V6) & inferior (II, III,
aVF)
Q waves in? - CORRECT ANSWER - in one or several of left lateral leads (I, aVL, V5,
V6), sometimes in inferior leads (II, III, aVF)
T wave positive in? - CORRECT ANSWER - Usually in leads w/ tall R waves; left lateral
(I, aVL, V5, V6) & inferior (II, III, aVF)
,R atrium enlargement? - CORRECT ANSWER - Leads II (parallel) & V1 (perpendicular;
biphasic)
1) P wave > 0.25 mV in II, III, aVF
aka "p pulmonale"
p pulmonale? - CORRECT ANSWER - RA enlargement, almost always related to
pulmonary system; usually causes backup into the ventricle & atria, causing enlargement of atria
L atrium enlargement? - CORRECT ANSWER - 1) V1 terminal portion, P > 1mm below
line
2) Terminal portion of P > 0.04 sec (1 small box)
"p mitrale"
p mitrale - CORRECT ANSWER - LA enlargement due to mitral valve issue
RVH - criteria - CORRECT ANSWER - 1) R > S in V1
2) R progressively smaller from V1-V6
3) S > R in V6
- will cause right axis deviation
(also tall R in III)
LVH - precordial criteria - CORRECT ANSWER - 1. V5: R > 26 mm
2. V6: R > 18 mm
**3. S (V1 or V2) + R (V5 or V6) > 35 mm (best)
4. V6 R > V5 R
axis is not a great indicator (L axis shift)
Sensitivity is low, specificity is high
LVH - limb criteria - CORRECT ANSWER - 1. aVL: R > 13 mm
, 2. aVF: R > 21 mm
3. I: R > 14 mm
4. R (I) + S (III) > 25 mm
2º repolarization in ventricular hypertrophy - criteria? - CORRECT ANSWER - 1. Down-
sloping ST segment depression
2. T wave inversion (R +, T -)
Tends to be most evident in leads most affected by size change
RVH = V1, V2
LVH = V5, V6
causes of arrhythmias - CORRECT ANSWER - HISDEBS: hypoxia, ischemia/irritability,
SNS, drugs, electrolytes, bradycardia, stretch (hypertrophy/enlargement)
symptoms of arrhythmias - CORRECT ANSWER - none, "palpitations," light-headedness,
syncope, angina, HF, sudden death
Types of arrhythmias - CORRECT ANSWER - 1. Sinus origin
2. Ectopic
3. Re-entrant (abnormally shaped path)
4. Conduction blocks (blocked signal)
5. Pre-excitation (shortcut in pathway)
Arrhythmias - 4 quick questions - CORRECT ANSWER - 1. Normal P waves?
2. Wide QRS? (> 0.12 sec indicates pacemaker below Bundle of His)
3. One P for every QRS?
4. Normal rate & rhythym?
Sinus arrhythmia - CORRECT ANSWER - Appearance is ALMOST NORMAL:
