ECG Review

Question 1

measuring HR on ECG:

Answer 1

300, 150, 100, 75, 60, 50, 42

Question 2

One of most common causes of ventricular and atrial dysrhythmias?

Answer 2

-slow conduction = yields tachycardic dysrhythmias

Question 3

Slow intercellular conduction due to:

Answer 3

1) small, non-longitudinally aligned cells
2) low phase 0 slope
- fewer open fast channels (ischemic purkinje cells)
- predominance of slow rather than fast channels
- normal for SA node cells and AV junction and node cells
3) closed (uncoupled) or few gap junctions
- uncoupling during ischemia (acidity, Ca buildup)