Which of the following accurately describes am ECG tracing f

-Which of the following accurately describes am ECG tracing for a patient who presents with an AV node block? circle one

a. absent p waves

b. absent QRS complexes

c. disconnected P waves and QRS complexes

d. inverted T waves

-The plateau of a cardiac action potential extends the depolarization state of cardiac muscle? true/false

-A patient with a damaged SA node is likely to experience a(n) ________ (decreased/increased) heart rates

Solution

1. b. absent QRS complexes

Explanation- QRS complexes are missing when there is AV node block as the AV node is not conducting all the impulses.

2. The plateau of a cardiac action potential extends the depolarization state of cardiac muscle? ---- false

Explanation- During plateau phase, the duration of the action potential is extended several folds relative to the action potential duration of skeletal muscle.

3. A patient with a damaged SA node is likely to experience a(n) __decreased______ heart rates.

Explanation- Damaged SA node slows down heart rate