FINAL Flashcards
(123 cards)
3 WAYS TO CALCULATE HR FROM EKG
1) number of QRS complexes in 6 second strip x 10
2) 300 / 150 / 100 / 75 / 60 / 50
3) 1500 / number of small squares between R waves
WHAT ARE THE LIMB LEADS
WHAT ARE THE PRECORDIAL LEADS
LIMB LEADS = I II III AVR AVL AVF
PRECORDIAL LEADS = V1 V2 V3 V4 V5 V6
WHAT IS THE J POINT ON EKG
Transition from S wave to T wave
- changes from vertical to horizontal
LIMB LEAD PLACEMENTS
AVR = right arm
AVL = left arm
AVF = left leg
I = AVR (-) to AVL (+)
II = AVR (-) to AVF (+)
III = AVL (-) to AVF (+)
SEPTAL LEADS
ANTERIOR LEADS
INFERIOR LEADS
LATERAL LEADS
SEPTAL LEADS = V1 V2
ANTERIOR LEADS = V3 V4
INFERIOR LEADS = II III AVF
LATERAL LEADS = I AVL V5 V6
NORMAL DURATIONS OF EACH EKG SECTION
P WAVES
PR INTERVAL
QRS COMPLEX
QT INTERVAL
P WAVES < 0.12 (3 boxes)
PR INTERVAL = 0.12 - 0.20 (3-5 boxes)
QRS COMPLEX = 0.04 - 0.12 (1-3 boxes)
QT INTERVAL = 0.36 - 0.44 (9 - 11 boxes)
WHAT DOES THE P WAVE INDICATE?
WHAT DOES THE Q WAVE INDICATE?
WHAT DOES THE QRS COMPLEX INDICATE?
WHAT DOES THE T WAVE INDICATE?
P WAVE = atrial depolarization
Q WAVE = interventricular septum depolarization
QRS COMPLEX = ventricular depolarization (atrial repolarization is hidden in there)
T WAVE = ventricular repolarization
RBBB CRITERIA
o QRS > 0.12
o rsR in leads V1 - V3 - “bunny ears”
LBBB CRITERIA
o QRS > 0.12
o deep S wave in V1/V2
o broad R waves in I, AVL, V5, V6
o absent Q wave in I, V5, V6; may have a slight or narrow one in AVL
o inverted T waves (or going opposite direction of QRS)
if Q wave is >/= 1/3 the height of R wave = indicative of
transmural MI
U WAVE
can be normal or pathologic
prominent U waves = hypokalemia
repolarization of purkinje fibers
RATES FOR
- SINUS RHYTHM
- BRADYCARDIA
- TACHYCARDIA
- SVT
sinus rhythm = 60-100
bradycardia < 60
tachycardia > 100
SVT = 150-200
significance of a prolonged PR interval
caused by a blocking of the conduction from the SA node to the AV node
1st degree AV block
prolonged PR interval (> 0.20)
PR interval should be 0.12 - 0.20 (3-5 boxes)
2nd degree AV blocks (2 of them)
o Type I (Wenckebach) = longer longer longer drop = PR interval progressively gets longer, until QRS complexes drops (doesn’t show up)
o Type II (Mobitz II) = PR interval is fixed, but some QRS complexes don’t show up (if some p’s don’t get through)
IVCD vs RBBB/LBBB
Intraventricular Conduction Delay = QRS complex > 0.12, but other criteria for bundle branch blocks not met
AXIS = look at leads ________
axis should never both be _________
If I is positive and AVF is positive =
If I is positive and AVF is negative =
If I is negative and AVF is positive =
I / II / AVF (supposed to look at I & AVF, but can compare I to II also)
should never both be negative = indeterminate
If both leads are positive (upwards) = normal
If I is positive and AVF is positive = normal
If I is positive and AVF is negative = LAD (left axis deviation)
If I is negative and AVF is positive = RAD (right axis deviation)
P WAVE MORPHOLOGY
BIPHASIC vs P PULMONALE vs P MITRALE
mostly look at lead II for R/L atrial enlargement
Evaluate leads II, III, AVF and V1 for atrial deformities
may be biphasic P waves in V1 = normal
normal = < 2.5mm in limb leads & < 1.5mm in precordial leads
mostly look at lead II to find this
P PULMONALE = Right atrial enlargement = right atrial depolarization lasts longer than left = will see a tall P wave in lead II and a biphasic wave with increased height of the initial positive p wave deflection (>1.5mm)
P MITRALE = Left atrial enlargement = lasts longer (not taller, but wider), > 0.12s. Notch in lead II, and increased depth of second negative p wave deflection in V1
RVH (right ventricular hypertrophy)
look at the precordial leads (V1 - V6)
tall R waves in V1 / V2 (get smaller as it goes to V5/V6)
deep S waves in V5 / V6 (start smaller in V1/V2)
***RVH should accompany RAD (right axis deviation)
LVH (left ventricular hypertrophy)
look at precordial leads (V1 - V6)
deep S waves in V1 / V2
tall R waves in V5 / V6
Amplitude of S wave in V1 + R wave in V5 = > 35mm
may also have inverted / asymmetrical / depressed T waves in lateral leads
Hypokalemia on EKG
Hyperkalemia on EKG
Hypokalemia = U waves
Hyperkalemia = peaked T waves (> 5mm in II/III) (> 10mm in V3/V4); can also have flattened P waves
Hypocalcemia on EKG
Hypercalcemia on EKG
Hypocalcemia = prolonged QT interval (can also seen with hypomagnesemia & hypokalemia & hypothermia)
Hypercalcemia = shortened QT interval; may see J wave
Hypothermia on EKG
J waves
prolonged PR, QRS, and QT
PE on EKG
S1Q3T3
***Most common finding = Sinus Tachycardia
S wave in lead I
Q wave in lead III
inverted T waves in lead III
transient RBBB`