Chapter 7 Abnormalities in the conducting system

Question 1

After sinus arrest, how long does it take before you faint?

Answer 1

10-15sec

Question 2

“____” is an umbrella term that includes bradycardia and sinus arrest

Answer 2

Sick sinus syndrome

Question 3

What are the two common breeds for Sick Sinus Syndrome?

Answer 3

WHWT and female miniature schnauzers

Question 4

What is sinus arrest?

Answer 4

SA does not create impulse which creates flatline. In between there is normal sinus rhythm.

Question 5

What is bradycardia-tachycardia syndrome?

Answer 5

Sick sinus syndrome where you have periods of bradycardia (such as sinus arrest), followed by supreventricular tachycardia

Question 6

What is a sinusventricular rhythm?

Answer 6

• Its atrial standstill
• The impulse is lead directly from SA node to the AV node without contracting the atria.
• Normal ECG (usually slow, <60/m) but with no P waves.
• Seen with hyperkalemia or atrial cardiomyopathy (atrial myocytes are too sick)

Question 7

Whats the difference between Morbitz 1 and Morbitz 2, 2nd degree AV block?

Answer 7

• Morbitz 1 has increased P-R interval with each beat

* Morbitz 2 has the same P-R interval with each beat, and the frequency between the blocks are usually constant

Question 8

What is a Wenckebach?

Answer 8

A low degree 2nd degree AV block (morbitz 2)

Question 9

What type of AV block are associated with clinical sings and needs treatment?

Answer 9

3rd degree, and 2nd degree morbitz 2

Question 10

Describe 3rd degree AV block?

Answer 10

• P waves with no conduction to the ventricle.
• P and QRS complexes are random and non dependent of each other
• P waves usually much quicker than QRS
• QRS can come from an ectopic site and is wide an bizarre without P wave
• QRS can also come from an ectopic site at the AV node or bundle of His (=juncitonal escape), causing a normal QRS complex