ECG Interpretation: Steps 3 & 4

rhythm

regularity, origin of the QRS

irregular rhythms

regular

regularly irregular

irregular

irregularly irregular

irregularly irregular rhythm

irregular rhythm with no pattern

all the QRS complexes occur at different intervals

atrial fibrillation

regularly irregular rhythm

irregular rhythm with a distinct cyclic pattern in which the heart rate gradually increases and decreases

sinus arrhythmias

origin of QRS complex: sinus

conduction sequence: SA node → atrial myocardium → AV node → His-Purkinje fibers → ventricular myocardium

p - narrow QRS complex - T

P & QRS - associated

origin of QRS complex: supraventricular (ectopic)

conduction sequence: atrial myocardium → AV node → His-Purkinje fibers → ventricular myocardium

P’ - narrow QRS complex - T

P & QRS - associated

origin of QRS complex: ventricular (ectopic)

conduction sequence: ventricular myocardium

wide QRS complex - T (NO P wave)

P & QRS - dissociated

QRS complex origin?

supraventricular

QRS complex origin?

ventricular

QRS complex origin?

sinus

box measurements at 25 mm/s

small box = 0.1mV & 0.04s

big box = 0.5mV & 0.2s

box measurements at 50 mm/s

small box = 0.1mmV & 0.02s

big box = 0.5mV & 0.1s

P wave amplitude and duration? normal or abnormal?

amplitude = 0.6 mV = abnormal

duration = 0.03 s = normal

P wave amplitude and duration? normal or abnormal?

amplitude = 0.15 mV = normal

duration = 0.06s = abnormal

the PR interval (also called the PQ interval is a measurement of the time the impulse takes to travel through what portions of the conducting system?

A. the atria

B. the atria and ventricles

C. the atria, AV node, His-purkinje system

D. the AV node, His-Purkinje system, and ventricles

B. the atria and ventricles

interval measurements