Category:Impulse Conduction Abnormalities

Sino-Atrial Block

Atrio-Ventricular Block

Atrial Standstill

Bundle Branch Block

Wolff-Parkinson-White Syndrome (Ventricular Preexcitation Syndrome

• This syndrome occurs when the conduction travels from the SA node and then completely bypasses the AV

node and travels to the bundle of His or the ventricles.

Causes

Hypertrophic cardiomyopathy (cats); congenital heart disorders

ECG Appearance: Short PR interval; Prolonged QRS complex; Notch in the R wave

Treatment

Treatment for tachycardia if necessary: digoxin, quinidine etc.

Sick Sinus Syndrome

• This is a blanket term used to describe multiple abnormalities of the SA node involving impulse formation and conduction disturbances.

Causes

Myocardial diseases, idiopathic, breed predispositions (e.g. miniature schnauzer)

ECG: Variable depending on the specific SA abnormality

Treatment

Surgical implantation of a pacemaker; +/- antiarrhythmic treatments