Cardio & Respiratory Wk 12 - Lesson 89

Where is lead I?

Right forelimb (negative) and left forelimb (positive)

3 multiple choice options

Where is lead II?

right forelimb (negative) and left hindlimb (positive)

3 multiple choice options

Where is lead III?

left forelimb (negative) and left hindlimb (positive)

3 multiple choice options

What is aVR?

augmented voltage from the right forelimb

What is aVL?

augmented voltage from the left forelimb

What is aVF?

augmented voltage from the left hindlimb

What wave is for atrial depolarization?

P wave

3 multiple choice options

What segment is for AV nodal conduction?

PR segment

3 multiple choice options

What is QRS interval for?

ventricular depolarization

What is the ST segment for?

phase 2 of action potential

What is the T wave for?

ventricular repolarization

What is an arrythmia?

abnormal rhythm of the heart

What is atrial fibrillation?

type of arrhythmia where the atria beat irregularly and often rapidly

What is atrial flutter?

atria beat very quickly but regularly

What is bradycardia?

slower than normal heart rate

What is a bundle branch block?

blockage in the hearts electrical conduction pathways within the ventricles

What is cardiomyopathy?

heart muscle disease that can lead to an abnormal ECG due to changes in the structure and function of the heart

What is dyspnea?

difficulty breathing

What is ectopic beat?

heartbeat that originates from an abnormal location within the heart

What is a ground electrode?

used as a reference point to stabilize the ECG readings, typically placed away from the heart

What is hypertrophy?

enlargement of the heart muscle which can increase electrical activity

What is infarction?

tissue death due to lack of blood supply

What are the standard leads?

I, II, III, aVR, aVL, aVF

3 multiple choice options

What is premature ventricular contraction?

premature heartbeat originating from the ventricles

What is sinus rhythym?

normal heart rhythm originating from the SA node

What is supraventricular tachycardia?

rapid heart rate originated above the ventricles

What is ventricular fibrillation?

life-threatening arrhythmia where the ventricles quiver rather than contract properly

What color electrode goes on the right forelimb?

white

3 multiple choice options

What color electrode goes on the left hindlimb?

red

3 multiple choice options

Where does the black electrode go?

left forelimb

3 multiple choice options

Where does the green electrode go?

right hindlimb

3 multiple choice options

Where does the ground electrode go?

right hindlimb; green

3 multiple choice options

What is the advantage to using unipolar leads?

generates larger signals since there are two electrodes for the negative electrode which can collect more currents

What does the depolarization vector look like?

positive head and negative tail

3 multiple choice options

What does the repolarization vector look like?

negative head and positive tail

3 multiple choice options

What does the ECG deflection look like for atrial depolarization?

upward deflection

What does the ECG deflection look like for atrial repolarization?

downward deflection

What does the ECG deflection look like for ventricular repolarization?

Upward deflection

What does the ECG deflection look like for ventricular depolarization?

upward deflection

What does the bounce back mean for ventricular repolarization?

depolarization occurs going toward the positive electrode but repolarization occurs going away from the positive electrode

What type of lead is best to be used in large animals like horses?

base-apex lead

In the base apex lead I arrangement, where are the leads placed?

right forelimb electrode is placed on the jugular groove and left forelimb electrode is placed on the left side of the thorax

In the base apex lead II arrangement, where are the leads placed?

right forelimb electrode is placed on the jugular groove and left hindlimb electrode is placed on the left side of the thorax

What can you see in a horses ECG that is normal?

biphasic P wave

What are the three rules for ECGs?

direction, vector speed, amount of tissue

How does vector speed affect the ECG?

faster vectors have narrow tracings while slow vectors have wider tracings

How does amount of tissue affect the ECG?

amount of tissue is proportional to the amplitude

How does direction affect the ECG?

direction of depolarization or repolarization affects which way the deflection on the ECG will go

What is the standard amplification settings on the ECG?

5 or 10 mm/mV

What is the standard paper speed settings on the ECG?

25-50 mm/sec

What is the benefit of a low paper speed?

you can see more random events and general idea of rhythmic events

What is the benefit to faster paper speed?

shows more details

What position should the patient be in for ECG?

right lateral recumbency; cats may tolerate sternal recumbency better

How can you ensure good electrical contact of the electrodes?

using coupling gel or alcohol

Where are the electrodes placed on the patients limbs?

elbows and stifles

Where should the ECG be performed?

on a electrically insulated surface and as far away from other main electrical equipment as possible

What are the two main things an ECG provides?

heart rate and rhythm

How to calculate heart rate with a 25 mm/sec paper speed?

use a bic pen (150mm) which is equal to 6 sec and count the number of complexes within the length of the bic pen and multiply by 10

How to calculate heart rate with a 50 mm/sec paper speed?

use a bic pen (150 mm) which is equal to 3 sec and count the number of complexes within the length of the bic pen and multiply by 20

What do normal rhythms tend to be?

regular or regularly irregular

What type of rhythm does atrial fibrillation have?

irregularly irregular

What is the mean electrical axis?

average of all depolarizations in the heart which refers to the direction of the general depolarization wave front

What is the normal orientation of the heart vector?

right shoulder to the left leg

Why does the heart vector point a little to the left?

the left ventricle has the highest muscle mass and thus generated the strongest signal