Chapter 8 - Changes in the P-QRS-T morphology Flashcards
1
Q
What is a wandering pacemaker and what is its significance?
A
- Significance is about the same as for sinus arrhythmia
- Wandering pacemaker is seen as a result of high vagal tone.
- The firing cells are shifting between SA node and other ectopic cells in the atria
2
Q
What does the ECG wave look like with large L atria?
A
- Wide and notched. The notch is due to asynchronized contraction of the atria.
- Also called P-mitrale
3
Q
What does the ECG wave look like with large R atria?
A
- Tall
- P-pulmonale
- Commonly seen in dogs with chronic airways disease
4
Q
What does the ECG wave look like with large L ventricle?
A
- Tall R in lead I = hypertrophy
- Tall R in lead I, II, III = dilation
- Sagging og S-T segment
5
Q
What does the ECG wave look like with large R ventricle?
A
Deep S waves
6
Q
Causes for S-T depression
A
- Myocardial ischemia
- Potassium imbalance
- Digitalis toxicity
7
Q
Causes for S-T elevation
A
- Severe full wall thickness myocardial ischemia or infarcts
* Pericarditis
8
Q
What are the diagnostic values of T wave morphology
A
The diagnostic value of T wave morphology in veterinary medicine is very limited compared to human medicine. It might be helpful if the morphology is compared over time in the same animal. Most often in vet med we see tall T waves associated with hyperK.
