ECG Abnormal Findings

Right Atrial Enlargement: Lead II

tall peaked P wave (>2.5mm)

RAE: V1

biphasic P wave

LAE Lead II

wide notched prolonged P wave (.12s)

LAE V1

biphasic P wave with negative side larger than positive

RVH V1 & V2

tall R waves

RVH V5 & V6

deep S waves

RVH Lead I

negative QRS

RVH V1

Positive QRS

RVH all leads

ST depression, T wave inversion

RVH mean axis

right axis deviation

LVH equation

S wave in V1/V2 + R wave in V5/V6 >35mm

LVH all leads

St depression and T wave inversion

LVH V1-V6

R wave amplitude greater or equal to 25mm

LVH aVL

R wave more than or equal to 11-13mm

1st degree AV block

Long PR segment with QRS following (>.2s)

2nd degree AV block Type I

Pr intervals progressively increase until QRS is dropped

2nd degree AV block Type II

PR intervals are constant with dropped QRS

3rd degree AV block

complete dissociation between P waves and QRS complexes, unchanged PR intervals

RBBB V1

wide positive QRS, rabbit ears

RBBB Lead I

S wave present (shouldn't be wider than half a box)

LBBB V1/V2

wide notched negative QRS (in most leads)

LBBB all leads

ST-T changes opposite of the R waves proceeding them

LBBB V5/V6

tall notched positive R waves

LBBB I, aVL, V5, V6

absence of small normal Q waves

LBBB mean axis

possible left axis deviation

STEMI ST elevation

aVL, I, V2, V4, V6

STEMI ST depression

II, III, aVF
*reciprocal findings

STEMI Q waves

pathologic findings: 1/3 height of QRS, .4s long

NSTEMI all leads

ST depression

NSTEMI reciprocal findings

NONE.

Artifact

NOT A PATIENT CONDITION

Artifact causes

patient movement,poor skin prep, old electrodes

Low voltage limb leads

QRS

Low voltage precordial lead

none with a total voltage of >15mm

Low voltage ecg calibration

must be properly calibrated to have this finding

Types of ST segment change

ST depression and ST elevation

ST depression due to oxygen demands

heart rate, wall stress, contractility

ST depression due to oxygen supply

blood flow

ST depression due to exercise ischemia

heart vessels are partially occluded which is made obvious by exercise, higher need for blood causes less blood to get through

T wave inversion reasons

coronary heart disease, angina pectoris

Digitalis effect

messes with baseline ST segments, cannot read for ischemia, causes sloping ST segment

Prinzmetal Angina

ST elevation

Ventricular Aneurysm

ST elevation, T wave inversion

Pericarditis all leads except aVR

ST elevation

Pericarditis all leads

PR segments are depressed

Early repolarization

ST elevation in normal hearts

Juvenile Pattern V1-V4

T wave inversion

Hypocalcemia

QT interval prolongation (>.44)

Hypercalcemia

QT interval shortened

Hypokalemia

prominent U wave (only visible during bradycardia)

Hyperkalemia

Tall, tented, peaked T wave, moves toward ventricular fibrillation

Normal Sinus Rhythm

Rhythm: regular
Rate: 60-100bpm
P waves (in LII): max .12s
PR interval: .12-.2s
QRS: less than .1

Sinus Arrhythmias

Rhythm: irregular & sinus
Rate: any rate
P waves, PR interval, QRS normal

Sinus Arrhythmias Breathing

Decreases on expiration, increases on inspiration

Sinus tachycardia

Rhythm: regular
Rate: higher than 100bpm
P waves: normal
PR interval: normal
QRS: normal

Sinus bradycardia

Rhythm: regular
Rate: less than 60 bpm
P wave, PR interval, QRS: normal

Sinus Exit Block

Dropped beat, beat comes back in line with rhythm from before

Sinus exit block PR intervals

PR intervals are normal and regular

Sinus Arrest

Dropped beat, rhythma before and after the pause do not line up

Premature Atrial Contraction (PAC)

Premature beat, narrow QRS complex

Blocked PAC

Look at T wave prior (big/different than others in same lead) & beat after

Blocked PAC physiology

PAC happens so quickly that heart cells are in absolute refractory period, unable to conduct impulse

Premature Junctional Contractions Three P wave options

Absent, inverted, retrograde

PJC: Absent P wave

atria and ventricles depolarize at same time

PJC: Inverted P wave

in correct sport, upside down, beat started at AV junction

PJC: Retrograde P wave

Ventricles depolarize between atria

Accelerated Junctional Rhythm: multiple leads

inverted P wave, P wave after QRS OR no P wave

Accelerated Junctional Rhythm: BPM

60-100 bpm

Atrial Tachycardia: all leads

three or more PAC that occur consecutively

Atrial Tachycardia: BPM

200 +/- 50 bpm

ST elevation

aneurysm, evolving MI, pericarditis, Prinzmetal angina, early repolarization

ST depression

ischemia, reciprocal change of MI, NSTEMI, R/L BBB, Digitalis, R/L VH

Left Anterior Hemiblock Lead I

small Q wave

Left Anterior Hemiblock Lead III

small R

Left Anterior Hemiblock QRS

QRS normal or widened to .1s

Left Anterior Hemiblock mean electrical axis

Left shift of electrical axis: -45 to -90

Left Posterior Hemiblock Lead I

small R wave

Left Posterior Hemiblock Lead III

Small Q wave

Left Posterior Hemiblock QRS

normal or widened to .1s

Left Posterior Hemiblock electrical axis

Rightward shift of electrical axis: 120 to 180