Regularity: irregular

Rate: approximately 80 bpm

P Waves: uniform P waves

with an irregular P–P

interval

PRI: 0.16 second and

constant

QRS: 0.08 second

Interp: Sinus Arrhythmia

4.5

Regularity: regular

Rate: 107 bpm

P Waves: uniform and

upright; regular

P–P interval

PRI: 0.16 second and

constant

QRS: 0.12 second

Interp: Sinus Tachycardia

(with a wide QRS)

4.6

Regularity: regular

Rate: 50 bpm

P Waves: uniform and upright; regular P–P interval

PRI: 0.12 second and

constant

QRS: 0.08 second

Interp: Sinus Bradycardia

4.7

Regularity: regular

Rate: 83 bpm

P Waves: uniform and upright; regular P–P interval

PRI: 0.16 second and

constant

QRS: 0.08 second

Interp: Normal Sinus

Rhythm

4.8

554 Answers Key

Regularity: regular

Rate: 94 bpm

P Waves: uniform and

upright; regular P–P

interval

PRI: 0.16 second and

constant

QRS: 0.12 second

Interp: Normal Sinus

Rhythm (with a wide QRS)

4.9

Regularity: slightly irregular

Rate: approximately 30 bpm

P Waves: uniform and

upright; irregular P–P

interval

PRI: 0.18 second and

constant

QRS: 0.08 second

Interp: Sinus

Bradyarrhythmia

4.10

Regularity: regular

Rate: 75 bpm

P Waves: uniform and upright; regular P–P interval

PRI: 0.18 second and

constant

QRS: 0.06 second

Interp: Normal Sinus Rhythm

4.11

Regularity: irregular

Rate: 90 bpm

P Waves: uniform and

upright; irregular P–P

interval

PRI: 0.20 second and

constant

QRS: 0.06 second

Interp: Sinus Arrhythmia

4.12

Regularity: regular

Rate: 48 bpm

P Waves: uniform and upright; regular P–P interval

PRI: 0.20 second and

constant

QRS: 0.08 second

Interp: Sinus Bradycardia

4.13

Regularity: irregular

Rate: approximately 70 bpm

P Waves: uniform and upright; regular P–P interval

PRI: 0.14 second and

constant

QRS: 0.06 second

Interp: Sinus Arrhythmia

4.14

Regularity: regular

Rate: 65 bpm

P Waves: uniform and

upright; regular

P–P interval

PRI: 0.16 second and

constant

QRS: 0.08 second

Interp: Normal Sinus

Rhythm

4.15

Regularity: regular

Rate: 115 bpm

P Waves: uniform and

upright; regular

P–P interval

PRI: 0.14 second and

constant

QRS: 0.16 second

Interp: Sinus Tachycardia

(with wide QRS)

4.16

Regularity: regular

Rate: 65 bpm

P Waves: uniform and

upright; regular

P–P interval

PRI: 0.12 second and

constant

QRS: 0.08 second

Interp: Normal Sinus

Rhythm

4.17

Regularity: irregular

Rate: approximately 80 bpm

P Waves: uniform and upright; regular P–P interval

PRI: 0.12 second and

constant

QRS: 0.08 second

Interp: Sinus Arrhythmia

4.18

Regularity: regular

Rate: 88 bpm

P Waves: uniform and

upright; regular

P–P interval

PRI: 0.16 second and

constant

QRS: 0.08 second

Interp: Normal Sinus

Rhythm

4.19

Regularity: regular

Rate: 150 bpm

P Waves: upright and

uniform

PRI: 0.12 second

QRS: 0.08 second

Interp: Sinus Tachycardia

4.20

Regularity: regular

Rate: 83 bpm

P Waves: upright and

uniform

PRI: 0.20 second

QRS: 0.12 second

Interp: Normal Sinus

Rhythm (with wide QRS)

4.21

Regularity: regular

Rate: 54 bpm

P Waves: upright and

uniform

PRI: 0.16 second

QRS: 0.08 second

Interp: Sinus Bradycardia

4.22

Regularity: regular

Rate: 107 bpm

P Waves: upright and

uniform

PRI: 0.12 second

QRS: 0.08 second

Interp: Sinus Tachycardia

4.23

Regularity: irregular

Rate: 70 bpm

P Waves: upright and

uniform

PRI: 0.20 second

QRS: 0.10 second

Interp: Sinus Arrhythmia

4.24

Regularity: irregular

Rate: 50 bpm

P Waves: upright and

uniform

PRI: 0.16 second

QRS: 0.08 second

Interp: Sinus

Bradyarrhythmia

4.25

Regularity: regular

Rate: 88 bpm

P Waves: upright and

uniform

PRI: 0.14 second

QRS: 0.08 second

Interp: Normal Sinus

Rhythm

4.26

Regularity: irregular

Rate: 50 bpm

P Waves: upright and

uniform

PRI: 0.14 second

QRS: 0.08 second

Interp: Sinus

Bradyarrhythmia

4.27

Regularity: regular

Rate: 107 bpm

P Waves: upright and

uniform

PRI: 0.16 second

QRS: 0.08 second

Interp: Sinus Tachycardia

4.28

Regularity: regular (very

slightly irregular)

Rate: 43 bpm

P Waves: upright and

uniform

PRI: 0.18 second

QRS: 0.11 second

Interp: Sinus Bradycardia

4.29

Regularity: irregular

Rate: 70 bpm

P Waves: upright and

uniform

PRI: 0.12 second

QRS: 0.08 second

Interp: Sinus Arrhythmia

4.30

3.1 Normal Sinus Rhythm

3.2 Normal Sinus Rhythm

(only very slightly

irregular)

3.3 Normal Sinus Rhythm

3.4 Sinus Tachycardia

3.5 Normal Sinus Rhythm

3.6 Sinus Tachycardia

3.7 Normal Sinus Rhythm

3.8 Normal Sinus Rhythm

3.9 Normal Sinus Rhythm

3.10 Sinus Arrhythmia

3.11 Normal Sinus Rhythm

3.12 Sinus Bradycardia

3.13 Normal Sinus Rhythm

3.14 Sinus Arrhythmia

3.15 Normal Sinus Rhythm

Interpretation of Chapter 3 Rhythm Strips

Answers Key 555

Regularity: regular

Rate: atrial rate is

300 bpm; ventricular rate

is 150 bpm

P Waves: uniform; sawtooth appearance

PRI: none

QRS: 0.10 second (QRS is

difficult to measure due

to obscuring by Flutter

waves)

Interp: Atrial Flutter with

2:1 response

5.2

Regularity: regular underlying rhythm interrupted

by an ectopic

Rate: 71 bpm

P Waves: uniform in underlying rhythm; one differently shaped P wave

before ectopic

PRI: 0.16 second and

constant

QRS: 0.10 second

Interp: Sinus Rhythm with

one PAC

5.3

Regularity: irregular

Rate: approximately 90

bpm

P Waves: not discernible;

undulations present

PRI: none

QRS: 0.12 second

Interp: Atrial Fibrillation,

controlled (with wide

QRS)

5.4

Regularity: regular

Rate: atrial rate is 328

bpm; ventricular rate is

82 bpm

P Waves: uniform; sawtooth appearance

PRI: none

QRS: 0.08 second

Interp: Atrial Flutter with

4:1 response

5.5

Regularity: irregular

Rate: approximately

50 bpm

P Waves: not discernible;

undulations present

PRI: none

QRS: 0.08 second (QRS

complexes are sometimes obscured by fibrillatory waves)

Interp: Atrial Fibrillation,

controlled

5.6

Regularity: regular underlying rhythm interrupted

by ectopics

Rate: 115 bpm

P Waves: uniform in the

underlying rhythm; shape

of P wave changes

before each ectopic

PRI: 0.12 second

QRS: 0.08 second; shape

of QRS is uniform in

both underlying beats

and ectopics

Interp: Sinus Tachycardia

with three PACs

5.7

Regularity: irregular

Rate: approximately 90 bpm

P Waves: not discernible;

undulations present

PRI: none

QRS: 0.08 seconds

Interp: Atrial Fibrillation,

controlled

5.8

Regularity: irregular

Rate: approximately

140 bpm

P Waves: not discernible

PRI: none

QRS: 0.06 second

Interp: Atrial Fibrillation,

uncontrolled

5.9

Regularity: regular underlying rhythm interrupted

by an ectopic

Rate: 65 bpm (rate

changes after the ectopic because sinus firing

mechanism resets itself)

P Waves: uniform in underlying rhythm; shape

differs in ectopic

PRI: 0.16 second and

constant; 0.20 second in

ectopic

QRS: 0.10 second

Interp: Sinus Rhythm with

one PAC

5.10

Regularity: irregular

Rate: atrial rate 300 bpm;

ventricular rate approximately 130 bpm

P Waves: uniform;

sawtooth appearance

PRI: none

QRS: 0.08 second

Interp: Atrial Flutter with

variable response

5.11

Regularity: irregular

Rate: approximately

80 bpm

P Waves: not discernible

PRI: none

QRS: 0.10 second

Interp: Atrial Fibrillation,

controlled

5.12

Regularity: regular

Rate: atrial rate is 332

bpm; ventricular rate is

83 bpm

P Waves: uniform; sawtooth in appearance

PRI: none

QRS: 0.08 second

Interp: Atrial Flutter with

4:1 response

5.13

Regularity: regular

Rate: atrial rate is 300

bpm; ventricular rate is

75 bpm

P Waves: uniform; there

are four P waves for

every QRS complex

PRI: none

QRS: 0.10 second

Interp: Atrial Flutter with

4:1 response

5.14

Regularity: irregular

Rate: 60 bpm

P Waves: morphology

changes

PRI: varies

QRS: 0.08 second

Interp: Wandering

Pacemaker

5.15

Regularity: irregular

Rate: approximately

80 bpm

P Waves: not visible; only

undulations are present

PRI: none

QRS: 0.04 second

Interp: Atrial Fibrillation,

controlled

5.16

Regularity: regular

Rate: atrial rate is 334

bpm; ventricular rate is

166 bpm

P Waves: uniform; sawtooth appearance; two

P waves for every QRS

complex

PRI: none

QRS: 0.10 second; slightly

obscured by Flutter

waves

Interp: Atrial Flutter with

2:1 response

5.17

Regularity: irregular

Rate: approximately

120 bpm

P Waves: not discernible;

only undulations are

present

PRI: none

QRS: 0.08 second

Interp: Atrial Fibrillation,

uncontrolled

5.18

Chapter 5

Regularity: irregular

Rate: approximately

100 bpm

P Waves: not discernible;

only undulations are

present

PRI: none

QRS: 0.08 second

Interp: Atrial Fibrillation,

controlled

5.1

556 Answers Key

Regularity: irregular

Rate: approximately

70 bpm

P Waves: not discernible;

only fine undulations are

present

PRI: none

QRS: 0.04 second

Interp: Atrial Fibrillation,

controlled

5.19

Regularity: irregular

Rate: approximately

110 bpm

P Waves: what appear to

be P waves do not map

out; they are actually

coarse fibrillatory waves

PRI: none

QRS: 0.06 second; QRS

complexes are obscured

by fibrillatory waves

Interp: Atrial Fibrillation,

uncontrolled

5.20

Regularity: irregular

Rate: approximately

150 bpm

P Waves: unable to map

out; undulations present

PRI: none

QRS: 0.06 second (QRS

complexes are obscured

by fibrillatory waves)

Interp: Atrial Fibrillation,

uncontrolled

5.21

Regularity: irregular

Rate: 70 bpm

P Waves: morphology

changes

PRI: varies

QRS: 0.08 second

Interp: Wandering

Pacemaker

5.22

Regularity: irregular

Rate: 80 bpm

P Waves: undulations

present

PRI: unable

QRS: 0.08 second

Interp: Atrial Fibrillation,

controlled

5.23

Regularity: regular underlying rhythm interrupted

by ectopic

Rate: 50 bpm

P Waves: upright and

uniform

PRI: 0.16 second

QRS: 0.14 second

Interp: Sinus Bradycardia

(with wide QRS) with one

PAC

5.24

Regularity: irregular

Rate: atrial rate 300 bpm;

ventricular rate 80 bpm

P Waves: sawtooth

appearance

PRI: unable

QRS: 0.10 second

Interp: Atrial Flutter with

variable response

5.25

Regularity: irregular

Rate: 100 bpm

P Waves: undulations

present

PRI: unable

QRS: 0.14 second

Interp: Atrial Fibrillation,

controlled (with wide

QRS)

5.26

Regularity: regular underlying rhythm interrupted

by ectopic

Rate: 65 bpm in underlying

rhythm; 70 bpm overall

P Waves: upright and

uniform

PRI: 0.18 second

QRS: 0.11 second

Interp: Sinus Rhythm with

one PAC

5.27

Regularity: regular

Rate: atrial rate 250 bpm;

ventricular rate 125 bpm

P Waves: sawtooth

appearance

PRI: unable

QRS: 0.08 second

Interp: Atrial Flutter with

2:1 response

5.28

Regularity: irregular

Rate: 120 bpm

P Waves: none visible

PRI: unable

QRS: 0.10 second

Interp: Atrial Fibrillation,

uncontrolled

5.29

Regularity: regular

Rate: atrial rate 284 bpm;

ventricular rate 71 bpm

P Waves: sawtooth

appearance

PRI: unable

QRS: 0.08 second

Interp: Atrial Flutter with

4:1 response

5.30

Regularity: irregular

Rate: 50 bpm

P Waves: none visible

PRI: unable

QRS: 0.08 second

Interp: Atrial Fibrillation,

controlled

5.31

Regularity: irregular

Rate: atrial rate 300 bpm;

ventricular rate 150 bpm

P Waves: sawtooth

appearance

PRI: unable

QRS: 0.08 second

Interp: Atrial Flutter with

variable response,

uncontrolled

5.32

Regularity: regular underlying rhythm interrupted

by ectopic

Rate: 50 bpm in underlying

rhythm

P Waves: upright in underlying rhythm; morphology changes in ectopic

PRI: 0.16 second

QRS: 0.14 second

Interp: Sinus Bradycardia

(with wide QRS) with one

PAC

5.33

Regularity: regular

Rate: atrial rate 272 bpm;

ventricular rate 136 bpm

P Waves: sawtooth

PRI: unable

QRS: 0.08 second

Interp: Atrial Flutter with

2:1 response

5.34

Regularity: irregular

Rate: 110 bpm

P Waves: none visible

PRI: unable

QRS: 0.08 second

Interp: Atrial Fibrillation,

uncontrolled

5.35

Regularity: irregular

Rate: 140 bpm

P Waves: undulations

present

PRI: unable

QRS: 0.08 second

Interp: Atrial Fibrillation,

uncontrolled

5.36

Regularity: regular underlying rhythm interrupted

by ectopic

Rate: 88 bpm

P Waves: upright and

uniform

PRI: 0.14 second

QRS: 0.10 second

Interp: Sinus Rhythm with

one PAC

5.37

Regularity: regular

Rate: atrial rate 272 bpm;

ventricular rate 136 bpm

P Waves: sawtooth

PRI: unable

QRS: 0.10 second

Interp: Atrial Flutter with

2:1 response

5.38

Regularity: irregular in

a pattern of grouped

beating

Rate: 80 bpm (including

ectopics)

P Waves: upright and

uniform

PRI: 0.12 second

QRS: 0.08 second (both

underlying rhythm and

ectopics)

Interp: Sinus Rhythm with

4 PACs (every other beat

is a PAC). This pattern

is called “bigeminy,”

which will be explained

in Chapter 8.

5.39

Answers Key 557

Chapter 6

Regularity: regular

Rate: atrial rate 272 bpm;

ventricular rate 136 bpm

P Waves: sawtooth

appearance

PRI: unable

QRS: 0.10 second

Interp: Atrial Flutter with

2:1 response

5.40

Regularity: regular

Rate: atrial rate 316 bpm;

ventricular rate 79 bpm

P Waves: sawtooth

appearance

PRI: unable

QRS: 0.08 second

Interp: Atrial Flutter with

4:1 response

5.41

Regularity: regular underlying rhythm interrupted

by ectopic

Rate: 65 bpm

P Waves: upright and

uniform

PRI: 0.14 second

QRS: 0.08 second

Interp: Sinus Rhythm with

one PAC

5.42

Regularity: irregular

Rate: 110 bpm

P Waves: none visible;

cannot map out

PRI: unable

QRS: 0.10 second

Interp: Atrial Fibrillation,

uncontrolled

5.43

Regularity: regular underlying rhythm interrupted

by ectopic

Rate: 54 bpm

P Waves: upright and

uniform

PRI: 0.16 second

QRS: 0.08 second

Interp: Sinus Bradycardia

with one PAC

5.44

Regularity: regular

Rate: atrial rate 200 bpm;

ventricular rate 100 bpm

P Waves: sawtooth

appearance

PRI: unable

QRS: 0.08 second

Interp: Atrial Flutter with

2:1 response

5.45

Regularity: irregular

Rate: 70 bpm

P Waves: none visible

PRI: unable

QRS: 0.10 second

Interp: Atrial Fibrillation,

controlled

5.46

Regularity: regular

Rate: atrial rate 272 bpm;

ventricular rate 136 bpm

P Waves: sawtooth

appearance

PRI: unable

QRS: 0.08 second

Interp: Atrial Flutter with

2:1 response

5.47

Regularity: regular underlying rhythm interrupted

by ectopics

Rate: 65 bpm

P Waves: upright and

uniform

PRI: 0.16 second

QRS: 0.08 second

Interp: Sinus Rhythm with

run of three PACs

5.48

Regularity: irregular

Rate: 100 bpm

P Waves: undulations

present

PRI: unable

QRS: 0.08 second

Interp: Atrial Fibrillation,

controlled

5.49

Regularity: regular underlying rhythm interrupted

by ectopic

Rate: 125 bpm

P Waves: upright and

uniform

PRI: 0.12 second

QRS: 0.08 second (in both

underlying rhythm and

ectopic)

Interp: Sinus Tachycardia

with one PAC

5.50

Regularity: regular

Rate: atrial rate 332 bpm;

ventricular rate 166 bpm

P Waves: sawtooth

appearance

PRI: unable

QRS: 0.11 second

Interp: Atrial Flutter with

2:1 response

5.51

Regularity: regular underlying rhythm interrupted

by ectopic

Rate: 65 bpm

P Waves: upright and

uniform

PRI: 0.16 second

QRS: 0.08 second (in both

underlying rhythm and

ectopic)

Interp: Sinus Rhythm with

one PAC

5.52

Regularity: regular underlying rhythm interrupted

by ectopic

Rate: 71 bpm

P Waves: upright and

uniform

PRI: 0.16 second

QRS: 0.08 second (in both

underlying rhythm and

ectopic)

Interp: Sinus Rhythm with

one PAC

5.53

Regularity: regular underlying rhythm interrupted

by ectopic

Rate: 68 bpm

P Waves: upright and

uniform

PRI: 0.16 second

QRS: 0.10 second (in both

underlying rhythm and

ectopic)

Interp: Sinus Rhythm with

one PAC

5.54