ECG

V1

4th intercostal space, right sternal border —> ventricular septum

V2

4th intercostal space, left sternal border —> ventricular septum

V3

Between V2 and V4 —> anterior wall of left ventricle

V4

5th intercostal space, midclavicular line —> anterior of left ventricle

V5

Lateral to V4 at the anterior axillary line —> lateral wall of left ventricle

V6

Lateral to V5 at the midaxillary line —> lateral wall of left ventricle

Artifact

Tracing on an ECG that is the result of interference, such as patient movement, rather than the heart’s electrical activity

12-lead ECG electrode placement

RA electrode - right arm on the wrist

LA electrode - left arm on the wrist

LL electrode - left leg on the thigh/ankle (or lower left side of the abdomen)

RL electrode - right leg on the thigh/ankle (or right abdomen)

12-lead ECG tracing electrode placement

V1 - right side of the sternum, between 4th-5th ribs

V2 - left side of the sternum across from V1

V4 - between 5th-6th ribs in a straight line down from the middle of the clavicle

V3 - halfway between V2 and V4 in between the 5th-6th ribs

V6 - horizontally even with V4 in a straight line down from the middle of the armpit

V5 - halfway between V4 and V6

QRS complex

Largest, narrow deflections on the ECG. Represents one contraction of the ventricles. Closer they are —> faster HR

The ST segment connects the end of the QRS complex and the beginning of the_______.

T wave

Horizontal distance between each wave on the ECG represents_________.

Time passing, each small (1-mm) box represents 0.04 sec and each larger (5-mm) box represents 0.20 sec. QRS complex should be less than 3 mm wide

If 2 QRS complexes are <15 mm apart (3 large boxes), the HR is__________.

>100 bpm, tachycardia

If the QRS complexes are >25 mm apart (5 large boxes), the HR is_______.

<60 bpm, bradycardia

P wave

Small rounded wave before the QRS, represents contraction of the atria

T wave

After each QRS complex, represents the ventricles recharging

Baseline

Horizontal line between all of the waves

Elevation of the ST segment above the baseline in a 12-lead ECG is an indication of_________ in progress.

Myocardial infarction