Page 41 - Rapid Review of ECG Interpretation in Small Animal Practice, 2nd Edition

Approach to Evaluating Arrhythmias

ECG criteria (Figs. 3.13, 3.14): VENTRICULAR FIBRILLATION
• Abnormally wide and bizarre QRS complexes as
Ventricular fibrillation (VF) is an irregular chaotic
VetBooks.ir • No associated P waves. rhythm during which there is no organized ventricular
compared to the normal sinus QRS complex.
contraction. VF is a fatal arrhythmia because it is
• Rate of ventricular beats is similar to (AV never self-terminating and is associated with little to
dissociation) or greater than the P wave rate no cardiac output. Electric defibrillation is the only
(VT). viable treatment option.
• Fusion beats are often present.
ECG criteria (Fig. 3.15):
• Chaotic and irregular deflections of varying
amplitudes.
• No distinguishable P, QRS, or T waves are
present.

Fig. 3.13 Dog, lead II, 50 mm/s showing ventricular Fig. 3.14 Dog, lead II, 50 mm/s showing ventricular
premature beats. tachycardia.

Fig. 3.15 Dog, lead II, 50 mm/s showing ventricular fibrillation.

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