|Normal sinus rhythm|
The rhythm is regular and the rate is 57/min. The P waves are uniform, upright, and precede the QRS complexes. No ectopic beats are seen. PR: . 14 sec, QRS: .08 sec, QT: .44 sec.
|1st degree block with sinus arrhythmia|
The rhythm is irregular. The R-R interval is .60 seconds between the 1st and 2nd complex and .72 seconds between the 8th and 9th complex. The rate is 80/min. The P waves are upright and precede the QRS complexes. The PR interval is slightly prolonged. PR: .22 sec, QRS: .08 sec, QT: .32 sec.
|Normal sinus rhythm with sinus pause|
The rhythm is irregular due to the pause. The rate is 80/min. The P waves are wide, upright, and some splitting. No ectopic beats are noted. There is a .96 second pause following the 3rd complex. PR: .16 sec, QRS: .08 sec, QT: .32 sec.
This rhythm is regular and the rate is 150/min. The question is whether to call the positive deflections that precede the QRS complexes P waves or T waves. This is where having other leads to compare is valuable. My guess is that there is some down slopping of the ST segment, Then a sharp upstroke to form a fused complex made of the T wave and the P wave. In this case we call the rhythm supraventricular tachycardia. Though some might argue that those positive deflections before the QRS complexes are P waves. Because the P waves are both wide and tall it suggests that the patient has some kind of biatrial enlargement. After the QRS complex there is some down slopping of the ST segment with what appears to be some T wave inversion. In this case we would call the rhythm sinus tachycardia. I am playing it safe and calling it SVT. Check the patient and check another lead.
The rhythm is regular with a rate of 51/min. The P waves are upright and precede the QRS complex. The are not any ectopic beats. PR: .12 sec. QRS: .08 sec, QT: .48 sec.