Question

Discuss rules and identifying characteristics of sinus rhythms, atrial rhythms, junctional rhythms, atrioventricular blocks, ventricular rhythms, asystole and paced rhythms.

Answer 1

Sinus rhythms: The heart rate is 60 to 100 beats per minute. ORS complex is preceded by normal P wave. P waves are upright. PR interval is constant. QRS complex is less than 100 ms wide.
Atrial rhythm: P waves are upright and precedes QRS complex but differ in shape. It might be flattened, notched, pointed, biphasic. QRS is usually less than 0.10 seconds but may be wide or absent.
Junctional rhythm: QRS duration is less than 120ms. Ventricular rate is 60 to 100 beats per minute. Retrograde P waves are seen before, during or after QRS complex. These retrograde P waves are inverted.
Atrio-Ventricular block: PR interval is longer. Of QRS interval is wide it indicates that it is complete block of one bundle.
Ventricular rhythm: Wide QRS complex with duration of more than 0.12 s. ST -T segments are in opposite directions to QRS complex.
Asystole: It is a flat line ECG. P waves and QRS complexes are not present.
Paced rhythm: Vertical spikes with short duration of 2 ms. Pacing spikes precedes P wave.