Ventricular pre-excitation in cats: 17 cases

Area of Science:

• Veterinary Cardiology
• Cardiac Electrophysiology
• Comparative Pathology

Background:

• Atrioventricular accessory pathways cause ventricular pre-excitation (VPE), leading to potential tachycardias.
• VPE is characterized by abnormal electrical conduction between the atria and ventricles.

Purpose of the Study:

• To investigate the clinical, electrocardiographic, echocardiographic, and outcome characteristics of cats with VPE.
• To compare cardiac structural and functional parameters between cats with VPE and healthy controls.

Main Methods:

• A multicenter, case-control, retrospective study involving 17 cats with VPE and 15 healthy controls.
• Data collected included clinical signs, electrocardiography, echocardiography, and patient outcomes.
• VPE diagnosis criteria included preserved atrioventricular synchrony, reduced PQ interval, and increased QRS duration with a delta wave.

Main Results:

• Most cats with VPE were male and non-pedigree, presenting with lethargy, tachypnea, or syncope.
• Cats with VPE exhibited significantly larger left and right atria and thicker interventricular septum and left ventricular free wall compared to controls.
• Tachyarrhythmias and ventricular arrhythmias were observed in several cats; congestive heart failure was uncommon.

Conclusions:

• Cats with VPE demonstrate distinct cardiac structural changes, including atrial enlargement and ventricular wall thickening.
• Despite these findings, cats with VPE experienced a relatively long survival period.
• VPE in cats is associated with significant electrophysiological and structural cardiac abnormalities.