Pulse Palpation, HR/Rhythm, ECGs

Question 1

Pulse Pressure

Answer 1

= SAP – DAP

Question 2

Advantages of Pulse Palpation

Answer 2

Proof of circulation, life
Technically easy to perform

Question 3

Disadvantages of Pulse Palpation

Answer 3

No numbers
No information about MAP
No indication of adequacy of tissue perfusion
Impaired by hypovolemia, VC

Question 4

Dagnall, Wilson, and Khenissi 2022 (VAA)

Answer 4

54 client owned dogs, palpation of femoral pulses had greatest likelihood of success with least amount of time versus radial, dorsal pedal and conscious and anesthetized dogs
o Monitoring femoral pulse during induction: confirmation of spontaneous circulation
o Pulse palpation improves with clinical experience

Question 5

Consequences of Abnormal Rhythms

Answer 5

o Altered, impaired CO
o Hypotension
o Increased MVO2, reduced coronary perfusion (tachyarrhythmias)
o Increased risk defibrillation +/- death

Question 6

High Heart Rate

Answer 6

tachycardia – shortened diastolic filling time, reduced SV

DDx
 Light level of ax: nociceptive response during sx, arousal
 Drugs: ketamine, anticholinergics, sympathomimetics
 Metabolic: hypovolemia, hypoxemia, hypercapnia, hyperthermia, pain
 Dz: pheo, hyperthyroidism
 Hz dz: SVT, VT

Question 7

General Tx Parameters for Tachycardia

Answer 7

20% above normal – poor CO, BP, tissue perfusion
 Large dogs >150, small dogs >190; cats >260
 Horses >55, SR >110

Question 8

Treatment Triggers for Ventricular (Tachy) arrhythmias

Answer 8

 Evidence of impaired forward flow (CO, BP, tissue perfusion)
 Concern for progression to vfib – 3 triggers

Question 9

3 Triggers for Concern about Progression to Vifb

Answer 9

• Rate >180-200bpm
• Progressive arrhythmia: increasing number, multiformity
• R-on-T: ectopic complex overlies preceding complex

If observable isoelectric period btw two complexes, no R on T

If last waveform runs into next waveform without isoelectric period (even once), R on T

Question 10

Low HR

Answer 10

bradycardia – diminishes CO
o DDx
 Ax agents: a2s, opioids, ax agent overdose
 Increased vagal tone: parasympathomimetics, ETT, abdominal nociception/traction, OCR, high BP, breed/species
 Metabolic: hypothermia, end-stage hypoxemia/severe myocardial hypoxemia, hyperkalemia
 Heart dz: SSS, AV conduction system

Question 11

Bradycardia Tx Guidelines

Answer 11

o Tx: 20-30% below baseline; CS of poor CO, BP, tissue perfusion
 <50 large dogs, <60 small dogs, <90 cats
 <25 horses, <55 SR

Question 12

ECG

Answer 12

• Voltmeter measuring electrical potential differences across heart – sum of vectors of depolarization APs, repolarization
  o Graphical representation of electrical activity of heart, represented by positive (neg to positive electrode), negative (pos to neg) deflections or flat lines (perpendicular to lead electrodes)

Question 13

Evaluation of ECG

Answer 13

o P for every QRS?
o QRS for every P?
o Regular rhythm?
o Appropriate rate?

Question 14

Lead I

Answer 14

3p
RA, LA

Question 15

aVL

Answer 15

2p

Question 16

Lead II

Answer 16

5p (60*)

Question 17

aVF

Answer 17

6p (90*)

Question 18

Lead III

Answer 18

7p (120*)

Question 19

aVR

Answer 19

10p

Question 20

Troubleshooting ECG

Answer 20

o Palpate pulse – ensure not PEA
o Correct lead placement
o Contact: dry, inadequate coupling gel
o Patient motion
o Exogenous electrical activity: MRI, cautery, external pacing

Question 21

Standard ECG Paper Speed

Answer 21

o Standard: 25mm/second – 1 small square (1mm) = 0.04s, 5 small squares = 1 large square, 0.2s, 5 large squares = 1 second
 300 large squares = 1 min

Question 22

Three methods for ECG Calculation based on paper speed

Answer 22

1. Large Square Method
2. Small Square Method
3. R to R interval method

Question 23

Large Square Method

Answer 23

Divide 300 by # of large squares btw each R-R intervals

Question 24

Small Square Method

Answer 24

1500 divided by number of small squares btw consecutive R waves

Question 25

R Wave Method

Answer 25

Rate = # of R waves (rhythm strip) x 6 – average rate over 10s

Question 26

Other Paper Species

Answer 26

50mm/sec: ECG appears drawn out with wider complexes
* 1mm (small square) = 0.02s
* 5mm (large square) = 0.1s

Question 27

Advantages of ECG

Answer 27

• Detect Arrhythmias
• Eval MEA – chamber enlargement
• Track response to therapy

Question 28

Disadvantages of ECG

Answer 28

• Complexes possible even if dead