Cardiology

Question 1

When the ventricles are neither being filled with blood (because the AV valves are shut) or ejecting blood (because the intraventricular pressure has not yet risen sufficiently)

Answer 1

Isovolumetric contraction

Question 2

The bipolar limb lead I electrodes are placed

Answer 2

Right arm and left arm

Question 3

The bipolar limb lead II electrodes are placed

Answer 3

Right arm and left leg

Question 4

The bipolar limb lead III electrodes are placed

Answer 4

On the left arm and left leg

Question 5

In the bipolar limb lead the electrode placed on the right leg is the

Answer 5

Ground lead

Question 6

When about half of the mass of the atria is depolarized, on the electrocardiogram, ___

Answer 6

The upward deflection of the p wave reaches a maximum value because the potential difference between the depolarized and stimulated atrial portions is at a maximum

Question 7

When the entire mass of the atria are polarized, the ECG P wave

Answer 7

Returns to baseline because all regions of the atria have the same polarity

Question 8

On the ECG, the S-T segment is related to the

Answer 8

Plateau phase of the cardiac action potential

Question 9

The T-wave on the ECG is produced by __ and is in the same direction as the QRS wave because ___

Answer 9

The repolarization of the ventricles; because, even though they are produced by opposite potential changes, ventricle depolarization occurs from the endocardium to epicardium and repolarization occurs from the epicardium to the endocardium

Question 10

Depolarization of the ventricles (indicated by a QRS wave on ECG) stimulates __

Answer 10

Stimulates contraction by promoting the uptake if Ca2+ into the region of the sarcomeres

Question 11

S1 is produced immediately after

Answer 11

The QRS wave (depolarization of the ventricles)

Question 12

Increasing intraventricular pressure resulting from ventricular contraction then causes __

Answer 12

The AV valves to close, which creates S1 (lub sound)

Question 13

Repolarization of the ventricles (indicated by T wave) occurs at the same time that the ventricles ___

Answer 13

Relax at the beginning of diastole

Question 14

Relaxation of the ventricles resulting from ventricular repolarization causes

Answer 14

A fall in intraventricular pressure, which causes the pulmonary and aortic semi lunar valves to close, making the S2 (dub) sound

Question 15

Sinus rhythm refers to the

Answer 15

Rhythm determined by the SA node

Question 16

Ventricular tachycardia results from

Answer 16

Abnormally fast ectopic pacemakers in the ventricles, which cause them to beat rapidly and independently of the atria

Question 17

Ventricular tachycardia is dangerous because

Answer 17

It can quickly degenerate into lethal ventricular fibrillation

Question 18

Flutter is defined as

Answer 18

Very rapid contractions (of atria or ventricles) that are coordinated

Question 19

Fibrillation is when (definition)

Answer 19

Contractions of different groups of myocardial fibers occur at different times, so that a coordinated pumping action of the chambers is impossible

Question 20

Atrila flutter usually

Answer 20

Degenerates quickly into atrial fibrillation

Question 21

In atrial fibrillation, the disorganized production of impulses __

Answer 21

Occurs rapidly and contraction of the atria is ineffectual.

Question 22

In atrial fibrillation, although the AV node doesn’t respond to all of the (disorganized) impulses, enough impulses __

Answer 22

Get through to to stimulate the ventricles to beat at a rapid rate.

Question 23

Atrial fibrillation reduces CO by ~15% because ___

Answer 23

The ventricles fill to about 80% of their end diastolic volume even before normal atrial contraction

Question 24

Fibrillation is caused by a continuous recycling of electrical waves known as __, through the myocardium

Answer 24

Circus rhythms

Question 25

Because of the long duration of myocardial action potentials, normally the entire myocardium __, but in circus rhythms, ___

Answer 25

enters a refractory period; some cells emerge from their refractory period before others, and electrical waves can be continuously regenerated and conducted, thereby producing uncoordinated contraction

Question 26

Circus rhythms may occur when the conduction pathway is __, or from an __, or __

Answer 26

Longer than normal (dilated cardiomyopathy); electric shock in the middle of a T wave; damage to the myocardium

Question 27

Electrical defibrillation does what?

Answer 27

Depolarizes all of the myocardial cells at the same time, causing them to enter a refractory state, stopping the circus rhythm conduction, and permitting the SA node to stimulate contraction normally

Question 28

AV node block (definition)

Answer 28

When damage to the AV node slows the impulse conduction, which is reflected by changes in the P-R interval

Question 29

First degree AV node block (definition)

Answer 29

Prolonged P-R interval

Question 30

Second-degree AV node block (describe)

Answer 30

When the AV node is damaged to the extent that 1 in every 2 to 4 atrial electrical waves passes through to the ventricles (on ECG, there are P waves without associated QRS waves)

Question 31

Describe what happens in third-degree (or complete) AV node block

Answer 31

None of the atrial waves can pass through the AV node to the ventricles. The atria are paced by the SA node and have a normal sinus rhythm, but the ventricles are paced by an ectopic pacemaker (usually in bundle of His or Purkinje fibers). Because SA node is the normal pacemaker, by virtue of it having the fastest cycle of electrical activity, the ectopic ventricular pacemaker results in a slower ventricular beat/rate and bradycardia results

Question 32

The AAFP recommends that the point-of-care probe test be used

Answer 32

To differentiate heart failure from respiratory disease in feline patients who present with acute dyspnea

Question 33

The quantitative (central laboratory) probe test is probably best used for

Answer 33

When there is high suspicion for cardiomyopathy (ie, patient has a heart murmur or articular bulge on DV or VD radiograph)

Question 34

A gallop sound (3rd +/- 4th heart sound) is generated by

Answer 34

The LV vibrating

Question 35

An inconsistently appreciated 3rd heart sound in a cat is likely

Answer 35

A systolic click (rather than an S3 or S4 gallop sound)

Question 36

Most dyspneic cats with pleural effusion have__ in their thoracic cavity

Answer 36

200-350mL of fluid in their thoracic cavity

Question 37

A normal serum CK in a paralyzed cat essentially rules out __ as the cause.

Answer 37

(F)ATE