3.2 - PPT EKG

Question 1

What does an EKG do?

Answer 1

Records the electrical activity of the myocardium

Question 2

Describe the basics of a typical EKG

Answer 2

P-Wave = atrial depolarization
QRS Complex = ventricular depolarization (& atrial repolarization)
T-Wave = ventricular repolarization

PR Interval = delay between atrial depolar & ventricular depolar
ST Segment = delay between ventricular depolar & atrial depolar

Question 3

Describe the basics of the different leads & electrodes

Answer 3

Lead II is the primary lead
Lead II = LL to RA

Lead I = LA to RA
Lead III = LL to LA

Question 4

What time duration do the “big boxes” represent?

“Little boxes”?

Answer 4

Big boxes = .2 sec

Little boxes = .04 sec

Question 5

Describe the conduction system of the heart

Answer 5

SA node = pacemaker of the heart

SA node - AV node - Bundle of His (R & L branches) - Purkinje fibers

Question 6

Describe the normal HR range for different age groups

Answer 6

Adults: 60-100 bpm
Children: 70-110 bpm
Newborns: 120-140 bpm (1-12 mos: 80-140 bpm)

Question 7

Describe the normal responses to exercise on an EKG

Answer 7

Increased p-wave height
Upsloping ST segment (NOT depression w/ upsloping ST)
Shorter QT intervals
Decreased R-wave height (not too big of a deal)

Question 8

Describe how to calculate HR using EKG

Answer 8

Count big boxes and use 300, 150, 100, 75, 60, 50 rule

Question 9

Describe the following atrial arrhythmias on an EKG

Wandering atrial pacemaker
Atrial flutter
Atrial fibrillation
Supraventricular tachyardia

Answer 9

Wandering atrial pacemaker - p-waves vary
Atrial flutter - “sawtooth pattern”
Atrial fibrillation - “squiggly worm”
Supraventricular tachycardia - normal EKG, but rapid rate

Question 10

Describe the following ventricular arrhythmias on an EKG

V-tach
V-fib
PVCs

Answer 10

Ventricular Tachycardia - “soon to be doom”; giant sawtooth; still regular beat
Ventricular Fibrillation - extremely irregular
PVCs - “wide & bizzare”; bigeminy; trigeminy; couplet; triplet

Question 11

What does ST segment elevation indicate?

Answer 11

Elevation >1 mm indicative of MI!

STEMI

Question 12

Is ST segment depression normal or abnormal?

Answer 12

Abnormal

Can be upsloping, downsloping, or horizontal

Question 13

Describe changes in the ST segment that are absolute vs relative indications to stop an exercise test

Answer 13

ST segment elevation >1 mm = absolute contraindication
ST segment depression >2 mm = relative contraindication

Question 14

Describe the different AV blocks & how they present on an EKG

Question 15

What is an inverted T wave indicative of?

Answer 15

L ventricular hypertrophy
Myocardial Ischemia

Question 16

Describe the absolute & relative contraindications to exercise based on EKG

Answer 16

Absolute:
- Sustained v-tach
- ST elevation > 1mm

Relative:
- ST / QRS changes - ST depression >2mm; downsloping ST-segment depression
- Arrhythmias other than sustained v-tach (supraventricular tachycardia; PVCs; >6 PVC’s per minute; PVC triplets; bradyarrhythmia; heart blocks)