a. Sinus arrhythmia
b. Sinus rhythm with PJCs
c. Sinus rhythm with PACs
d. 2nd degree AV block type
a. Complete heat block
b. Accelerated idioventricular rhythm
c. Accelerated junctional rhythm
d. Ventricular paced
a. Complete heart block
b. Second degree AV block type II
c. Second degree AV block type I
d. First degree block
4. The Great Escape.
When the SA node fails to generate an impulse, other pacemakers cells within the heart can take over and stimulate the myocardium. In this example we have a rhythm strip with sinus bradycardia. The 4th beat is a PVC which is followed by long pause. During this pause two ventricular escape beats are initiated. The rate of the escape beats is around 40/min which falls within the expected inherent rate of a ventricular induced rhythm.
a. Normal sinus rhythm
b. Sinus bradycardia
c. First degree heart block
d. Second degree heart block type II
1. c. Sinus rhythm with PACs. The rhythm is irregular with a rate of 80/min. The p waves are upright not are not all uniform. The QRS complexes are narrow. Some PACs are seen, the 4th, 7th, and 8th complexes. The P waves of the PACs are merged with the T waves of the complexes that precede them. There are also some morphological differences in the P waves as well. PR: .16 sec. QRS: .08 sec, QT: .44 sec. Interpretation: Sinus rhythm with PACs.
2. d. Ventricular paced. The rhythm is regular. The heart rate is 83/min. No P waves are seen. There is a single ventricular pacer spike that precedes each QRS complex. No ectopic beats are present. PR: ---, QRS: .16 sec, QT: .44 sec. Interpretation: Ventricular paced
3. a. Complete heart block. The rhythm is regular with a ventricular rate of 50/min. The P waves are upright but they are not paired with a QRS complex. The atrial rate is 75/min. The QRS complexes are wide and dissociated from the P waves. No ectopic beats are seen. PR: ---, QRS: .16 sec, QT: .52 sec. Interpretation: Complete heart block
5. c. First degree heart block. The rhythm is regular with a rate of 60/min. The P waves are uniform and upright and have a corresponding QRS complex. The PR interval is prolonged. The QRS complex is wide. The ST segment is slightly elevated. No ectopic beats are seen. PR: .28 sec, QRS: .12 sec, QT: .40 sec. Interpretation: 1st degree block