Author Question: Complete the following ECG criteria for a sinoatrial (SA) block: Rhythm ... (Read 112 times)

Bernana · **on:** Jun 25, 2018

Complete the following ECG criteria for a sinoatrial (SA) block:

Rhythm ___________________ ___________________ __
Rate ___________________ ___________________ __
P waves ___________________ ___________________ __
PR interval ___________________ ___________________ __
QRS duration ___________________ ___________________ __

Fill in the blanks with correct word

Question 2

Complete the following ECG criteria for a sinus tachycardia:

Rhythm ___________________ ___________________ __
Rate ___________________ ___________________ __
P waves ___________________ ___________________ __
PR interval ___________________ ___________________ __
QRS duration ___________________ ___________________ __

Fill in the blanks with correct word

kkenney · **Reply #1 on:** Jun 25, 2018

Answer to Question 1

Rhythm Irregular because of the pause caused by the SA block; the pause is the same as (or an exact multiple of) the distance between two other P-P intervals.
Rate Usually normal, but varies because of the pause.
P waves Positive (upright) in lead II, P waves look alike; when present, one precedes each QRS complex.
PR interval 0.12 to 0.20 seconds and constant from beat to beat.
QRS duration 0.11 seconds or less unless abnormally conducted.

Answer to Question 2

Rhythm P-P interval regular, R-R interval regular.
Rate 101 to 180 beats/min.
P waves Positive (upright) in lead II, one precedes each QRS complex, P waves look alike; at very fast rates, it may be hard to tell the difference between a P wave from a T wave.
PR interval 0.12 to 0.20 seconds (may shorten with faster rates) and constant from beat to beat.
QRS duration 0.11 seconds or less unless abnormally conducted.