Summary of Cardiac Rhythms

Question 1

<40
40-60
regularity: regular
rate: <60
P waves: present; 1:1
PR Interval: normal
QRS: normal

Answer 1

Sinus bradycardia

Question 2

60-100
regularity: regular
rate: 60-100
P waves: present; 1:1
PR Interval: normal
QRS: normal

Answer 2

Sinus rhythm

Question 3

> 100
regularity: regular
rate: >100
P waves: present; 1:1
PR Interval: normal
QRS: normal

Answer 3

Sinus tachycardia

Question 4

P waves: normal; 1:1
QRS: normal

Answer 4

Site of origin: sinus node

Question 5

P waves: abnormal or absent
QRS: normal

Answer 5

Site of origin: atrial tissue

Question 6

P waves: more Ps than QRSs
QRS: usually normal

Answer 6

Site of origin: Blocks

Question 7

P waves: absent
QRS: wide

Answer 7

Site of origin: Ventricular

Question 8

P waves: none
PR interval: absent
QRS: wide
regularity: irregular
rate: dependent on underlying rhythm
P waves: no P prior to early QRS
P: QRS ratio: P>QRS
PR Interval: none for early beat
QRS: >0.12 for early QRS
wide and bizarre; not a rhythm

Answer 8

ventricle (PVC)

Question 9

regularity: usually regular
rate: >100
P waves: not seen
PR Interval: unable to measure
QRS: normal

Answer 9

SVT

Question 10

regularity: atrial chaotic; ventricular irreg
rate: atrial >400 bpm; ventricular controlled <100; uncontrolled >100
P waves: none; chaotic baseline between T wave and QRS
PR Interval: none
QRS: normal

Answer 10

afib

Question 11

regularity: irregular
rate: dependent on underlying rhythm
P morphology: present of P’
P:QRS ratio: P=QRS
P waves: present; 1:1
PR Interval: normal; may be abnormal
QRS: normal
not a rhythm

Answer 11

PAC

Question 12

regularity: regular
rate: A=0; V>100
P morphology: absent
P:QRS ratio: P<QRS
PR Interval: N/A
QRS: >0.12
torsades is a form of VT and is regular
potentially lethal

Answer 12

vtach

Question 13

regularity: irregular
rate: indeterminate
P morphology: absent
P:QRS ratio: P<QRS
PR Interval: N/A
QRS: >0.12; fibrillatory waves
course baseline only - irregular
potentially lethal

Answer 13

vfib

Question 14

regularity: irregular
rate: 0
P morphology: absent
P:QRS ratio: N/A
PR Interval: N/A
QRS: absent
flat line, may just have P waves
potentially lethal

Answer 14

asystole

Question 15

regularity: dependent on underlying rhythm
rate: dependent on underlying rhythm
P morphology: dependent on underlying rhythm
P:QRS ratio: dependent on underlying rhythm
PR Interval: dependent on underlying rhythm; prolonged > 0.20
QRS: >0.12
not a rhythm
always with an underlying rhythm

Answer 15

first degree AVB

Question 16

regularity: regular atrial; irregular ventricular
rate: usually 60-100
P morphology: same, smooth, rounded
P:QRS ratio: P>QRS
PR Interval: lengthening PR; progressively lengthens until a QRS is dropped
QRS: <0.12
may have a pattern of “Foot Prints”

Answer 16

second degree AV block, type 1 Wenckebach

Question 17

regularity: regular
rate: A = usually 60-100; V = may be slow
P morphology: same, smooth rounded
P:QRS ratio: P>QRS
PR Interval: usually 0.12-0.20; may be prolonged; either normal or prolonged but constant
QRS: prolonged/WNL

Answer 17

2nd AVB, type II

Question 18

regularity: regular
rate: A = usually 60-100; V = usually <60
P morphology: same, smooth, rounded
P:QRS ratio: P>QRS
PR Interval: Highly variable, no pattern; not constant
QRS: Generally >0.12

Answer 18

3rd AVB, CHB