Sinus Bradycardia Regularity: The R-R intervals are constant; the rhythm is regular. Rate: The atrial and ventricular rates are equal; heart rate is less than 60 bpm. P wave: There is a uniform P wave in front of every QRS complex. PRI: The PR interval measure between 0.12 and 0.20 seconds; the PRI measurement is constant across the strip. QRS: The QRS complex measures less than 0.12 seconds. Sinus Tachycardia Regularity: The R-R intervals are constant; the rhythm is regular. Rate: The atrial and ventricular rates are equal; heart rate is greater than 100 bpm (usually between 100-160 bpm). P wave: There is a uniform P wave in front of every QRS complex. PRI: The PR interval measure between 0.12 and 0.20 seconds; the PRI measurement is constant across the strip. QRS: The QRS complex measures less than 0.12 seconds.
Atrial Fibrillation Regularity: The atrial rhythm is unmeasurable, all atrial activity is chaotic. The ventricular rhythm is grossly irregular, having no pattern to its irregularity. Rate: Atrial rate cannot be determined. If the ventricular rate is below 100 bpm (controlled), over 100 bpm (rapid ventricular response). P wave: None PRI: Since no P waves are visible, no PRI can be measured. QRS: The QRS complexes should be less than 0.12 seconds. Supraventricular Tachycardia SVT (150-250 bpm), is not the name of a specific arrhythmia. It is a term that s used to describe a category of several regular tachyarrhythmias that can t be identified more accurately because they have indistinguishable P waves and fall within a common rate range.
Atrial Flutter Regularity: The atrial rhythm is usually regular. The ventricular rhythm will be regular if the AV node conducts impulses through in a consistent pattern. If the pattern varies, the ventricular rate will be irregular. Rate: Atrial rate (250-350 bpm); Ventricular rate will depend on the ratio of impulses conducted through to the ventricles. P wave: Flutter waves (sawtooth appearance) PRI: Due to the unusual (Flutter) P wave, and the proximity of the wave to the QRS complex. PRI is not measured in Atrial flutter. QRS: The QRS complex measures < 0.12 seconds. There is no electrical activity, only a straight line. Asystole
Ventricular Tachycardia Regularity: This rhythm is usually regular, although it can be slightly irregular. Rate: Atrial rate cannot be determined. Ventricular rate (150-250 bpm), if the rate is below 150 bmp (slow VT); greater than 250 bpm (V. Flutter). P wave: None PRI: None QRS: The QRS complexes will be wide and bizarre, measuring at least 0.12 seconds. It is often difficult to differentiate between the QRS and T wave. Ventricular Fibrillation Regularity: The baseline is totally chaotic. Rate: The rate cannot be determined since there are no discernible waves or complexes to measure. P wave: No discernible P waves. PRI: None QRS: There are no discernible QRS complexes.
Premature Atrial Contraction (PAC) Regularity: Since this is a single premature ectopic beat, it will interrupt the regularity of the underlying rhythm. Rate: Depend upon the rate of the underlying rhythm. P wave: The P wave of the premature beat will have a different morphology than the P waves of the rest of the strip. The ectopic beat will have a P wave, but it can be flattened, notched, or otherwise unusual. It may be hidden within the T wave of the preceding complex. PRI: 0.12-0.20 seconds, but can be prolonged; the ectopic PRI will be different from other normal complexes. QRS: QRS complex measurement will be less than 0.12 seconds.
Premature Ventricular Contraction (PVC) Unifocal PVCs Originated from a single ectopic focus and are all uniform in configuration. Multifocal PVCs Many foci are initiating the ectopics; more serious than unifocal PVCs because they are associated with a more irritable myocardium.
Premature Ventricular Contraction (PVC) Bigeminy When the PVCs are falling in a pattern of every other beat with the normal beats. Trigeminy A repetitive cycle of 3 beats (1 PVC + 2 sinus beats)
Premature Ventricular Contraction (PVC) Quadrigeminy A pattern of 4 beats (1 PVC + 3 normal beats) First Degree Heart Block Regularity: Depend upon the regularity of the underlying rhythm. Rate: The rate will depend on the rate of the underlying rhythm. P wave: The P waves will be upright & uniform. Each P wave will be followed by a QRS complex. PRI: The PRI will be constant across the entire strip, but it will always be greater than 0.20 seconds. QRS: The QRS complex measurement will be less than 0.12 seconds.
Morbiz I (Wenkebach) Regularity: The R-R interval is irregular in a pattern of grouped beating Rate: Since some beats are not conducted, the ventricular rate is usually slightly slower than normal (< 100 bpm). Atrial rate (60-100 bpm). P wave: Upright & uniform. Some P waves are not followed by QRS complexes. PRI: The PRI will get progressively longer, until one P wave is not followed by a QRS complex. After the blocked beat, the cycle starts again. QRS: The QRS complex measurement will be less than 0.12 seconds. Type II Second Degree Heart Block P-P: Regular R-R: Usually regular (can be irregular if conduction ratio varies) PRI: Constant on conducted beats (can be greater than 0.20 seconds) Conduction: More P waves than QRS complexes
Third Degree Heart Block (CHB) P-P: Regular R-R: Regular PRI: PRI not constant; no relation of P waves to QRS complexes Conduction: More P waves than QRS complexes