Page 71 - Basic Monitoring in Canine and Feline Emergency Patients

During the
tachycardia, is the
VetBooks.ir rhythm regular or
irregular?

Irregular Regular

Are QRS complexes
Atrial fibrillation normal or
(see Fig. 3.13)
abnormal?

Normal Abnormal

Are P waves and PR Ventricular
intervals normal or tachycardia
abnormal? (see Fig. 3.9)

Normal Abnormal

Supraventricular
Sinus tachycardia
(see Fig. 3.8) tachycardia
(see Fig. 3.12)

Fig. 3.14. Algorithm for ECG diagnosis of tachyarrhythmias.

Fig. 3.15. Lead II ECG (25 mm/s, 10 mm/mV) showing sinus rhythm with 2nd-degree AV block. The sinus rate
(P wave rate) is 100 bpm, while the ventricular rate (actual heart rate) is approximately 50 bpm. Every other P wave
is conducted normally through the AV node to result in a normal P−QRS–T complex, while alternate P waves are not
conducted (blocked; see arrows).

Electrocardiography 63