8/13/2019 Medicine - EKG - Lab Coat Pockets

1/1

0

-30

-60-90

-120

-150

180

150

12090

60

30

aVR aVL

aVF

I

III II

Left axis

deviation

Normal

Extreme axis

deviation

Right axis

deviation

EKGBasic Analysis

Rate1. Determine ventricular (R-R) & atrial (P-P) rates

a. Use or b. Small box = 1mm, speed = 25mm/sec

i. Small box = 0.04 secii. Big box = 0.2 sec

iii. 5 big boxes = 1 sec2. Normal = 60-100 bpm. 100 = tachyRhythm

1. Normal sinusrhythm= normal rate& each P wave followed by QRSAxislimb leads only!

1. Determine quadrantusing I and aVF2. Axis is perpendicularto isoelectric lead3. Interpolateif no isoelectric lead foundLeft Axis Deviation: DDx

LVH Inferior MI Left anterior hemiblock WPW syndrome LBBB Normal variant

Right Axis Deviation:DDx

RVH (COPD, congenital heart dz) Right ventricular strain (PE,

other acute lung dz)

Left posterior hemiblock WPW syndrome Normal variant

Notes:

If wide QRS0.12 sec (e.g. BBB), use first 0.08 sec only P wave axis should be in normal quadrant T wave axis should be within 60-70 of QRS axis

Intervalsuse limb leads!

Interval Normal

1.PRinterval 0.12to 0.2 s2.QRSduration < 0.12 s (Note: QRS = 0.12 is WIDE!)3.QTinterval

< R-R interval(estimate); -

(correction) with HR in exercise, with meds(quinidine, procainamide, phenothiazines) in M vs F, also with serum Ca / Mg

Wave FormWave Look for Why:

Q Wide Q(0.04s)

Pathological Qwave, except if:

Only in lead III = diaphragmaticIn aVR (may have QS / Qr)In V1(may have QS)

QRS

Low QRS voltage

(< 5 mm in limb

leadsandS @ V3-V4

Early transition(R>S @ V2-V3)

Leads too far to pts left, orHeart rotated counterclockwise (LV to right)

Poor R-wave progression(little R V1-3, S>R in V4)

Leads too far to pts right, orHeart rotated clockwise (LV to left)

Early R-wave development*(R>S in V2)RVH, RBB, posterior MI, WPW syndrome(* alwaysabnormal if R>S in V1)

ST Elevation

Pathology: MI, etc. (worry if >1mm elev.)

Normal variants:

Junctional ST elevation (in V1-V3)early repolarization (in V4-V6)

o 2-3 mm, smooth/curving shapeT

Axis Should be within 60-70 of QRS axis, upright in V2-6

SizePeaked (> 10mm)suggests hyperKFlatsuggests hypoKbut nonspecific

U Presence Normal variant; can be seen in hypoK

1.Rate2.Rhythm3.Axis4.Intervals5.Wave form

Summary