ECG/EKG Analysis
(Redirected from EKG Analysis)
Calibration[edit | edit source]
- paper speed is normally 25mm/second
- therefore each 1mm box in the x axis = 0.04sec
- a 1mV test pulse is normally over 10 mm
- therefore each 1mm box in the y axis = 0.1 mV
Rhythm[edit | edit source]
- P wave upright in I, II, AVF
- PR interval > 0.12
- P wave for every QRS
- QRS for every P wave
Rate[edit | edit source]
- 300,150,100,75, 60, 50 rule
- If rhythm is not normal count the number of QRS complexes in 25 big boxes (5 seconds) and multiply by 12
- (an alternative method is to count the number of QRS complexes in a 10 second duration and multiply by 6)
- tachycardia >100bpm
- bradycardia <60bpm
Axis[edit | edit source]
- QRS upright in I and aVF
- If not upright in aVF look @ II
- If upright then axis is normal
- If not then there is left axis deviation
Intervals[edit | edit source]
- PR 0.12-0.20 (3-5 squares)
- QRS < 0.10 (2.5 square)
- QT <0.44 (11 squares)
Atrial enlargement[edit | edit source]
- Right atrium - lead II - p wave wave's initial component is enlarged, taller 2.5mm
- Left atrium - Lead V1 - p wave downward deflection of terminal component
Ventricular hypertrophy[edit | edit source]
- Right ventrical - tall R waves in V1 and V2, deep S in V6
- Left ventrical - tall R wave in V6, deep S in V1, plus one of
- R in V5/6 > 26mm
- S in V1 or 2 + R in V5 or V6 > 35 mm
- R+S in any chest lead > 45mm
- R in aVL > 11mm
- R in I > 15mm
Bundle Branch Blocks[edit | edit source]
note: normally depolarization of the ventricular septum is stimulated by a branch of the left bundle
incomplete block: QRS 0.10-0.12 (2.5-3 squares) complete block: QRS > 0.12 (3)
RBBB[edit | edit source]
- R' in V1
- S in V6
LBBB[edit | edit source]
- absent normal R in V1 and Q in V6 (initial depolarization directed to LV)
- terminal R' in V6 and downward deflection in V1
LAFB[edit | edit source]
- Q wave in I, aVL
- initial R wave in II, III, aVF
LPFB[edit | edit source]
- Q in II, III, aVF
- initial R wave in I, aVL
Q waves[edit | edit source]
- may be normal in V6 and aVL
- pathologic > 0.04, depth >25% QRS height
Inferior: II, III, aVF RCA Anteroseptal: V1-V2 LAD Anteroapical: V3-V4 LAD (distal) Aterolateral: V5-V6, I, aVL CFx Posterior: V1-V2 (tall R, no Q) RCA
MI[edit | edit source]
- ST elevation - returns to baseline in days
- T wave inversion - weeks to months
- Q wave - persists
- if ST remains elevated - fibrotic scar (ventricular anurysm) developed
Pericarditis[edit | edit source]
- diffuse ST elevation
- PR depression
Hyperkalemia[edit | edit source]
- tall "peaked" T waves
- flat p
- wide QRS
Hypokalemia[edit | edit source]
- U wave
- ST depression
- flat T
Hypercalcemia[edit | edit source]
- decreased QT interval
Hypocalcemia[edit | edit source]
- increased QT interval
External link[edit | edit source]
- EKG Reference Guide - Arrhythmia lessons, drills and tracings
- EKG Academy – free EKG lectures, drills and quizzes