Question

5.Discuss rules and identifying characteristics of sinus rhythms, atrial rhythms, junctional rhythms, atrio- ventricular blocks, ventricular rhythms, asystole and paced rhythms 6.Identify ectopic "beats" and rhythms 7.Accurately interpret a variety of EKG rhythms from 6 second strips 8.Demonstrate knowledge of physiologic and pharmacologic effects on EKG

Answer 1

5 Normal sinus rythm characteristics

• P wave will be normal 0.06 to 0.12 sec
• PR interval from 0.12 to 0.20
• QRS complex from 0.04 to 0.12
• T wave 0.16sec
• QT interval 0.34 to 0.43 sec.

Junctional dysrhytmias

• Rate and rythm is 40-140b/mt and regular.
• pwave inverted ,maybe hidden in QRS complex.
• PR intervl variable
• QRS complex normal

Atrial rythms

Atrial flutter

• 250 to 350 b/mt and regular.
• In Pwave flutter waves are present ,more flutter waves than QRS complexes,may occur in 2:1,3:1 pattern.
• PR interval not measurable.
• QRS complex is normal.

Atrial fibrillation

• Atrial-350 to 600b/mt and irregular.
• Pwave fibrillatory waves.
• PR interval not measurable.
• QRS complex normal.

AV Blocks

First degree

• Rate and rythm are normal and regular.
• P wave normal.
• PR interval >0.20sec
• QRS complex normal.

Second degree AV block Type 1

• Atrial:Normal nd regular
• ventricular -slower and irrregular.
• Pwave-normal
• PR interval progressive lengthening
• QRS complex-Normal QRS width ,with pattern of one non conducted QRS complex.

Type 2

• Atrial-normal and regular.
• Ventricular-slower and regular or irregular.
• More p waves than QRS complexes.
• PR interval normal or prolonged.
• QRS complex -widened QRS ,preceded by two or more p waves ,with non-conducted QRS complex.

Type 3

• Atrial-regular but may appeat irregualr due to p waves hidden in QRS complexes.
• ventricular -20 to 40 b/min and regular.
• P wave -normal ,but no connection with QRScomplex.
• PR inteval variable.
• QRS complex-normal or widened,no relationship with p waves.

Asystole

it represents the total absence of ventricular electrical activity.Ocassionally,p waves can be seen.No ventricular contraction occurs because depolarization does not occur.Patients are unresponsive,pulseless and apneic.This is a lethal dysrythmia and requires immediate treatment.ventricular fibrilltion may masquerade as asystole,thus the rythm should be assessed in more than one lead.

Pulseless electrical activity

it describes a situation in which electrical activity can be observed on ECG ,but there is no mechanical activity of the ventricles and the patient has no pulse.

6 Ectopic beats an occur early prior to normal sinus beat called premature beats or they can occur late in place of the normal sinus beat called escape beats.Benign ectopic beats are infrequent,unifocal and isolated.Clinically significant ectopic beats are frequent,multifocal and coupled.significant ectopic beats can lead to ventricular tachycardia,ventricular fibrillation and ventricular asystole.