Page 44 - Rapid Review of ECG Interpretation in Small Animal Practice, 2nd Edition

Treatment of Arrhythmias

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Defect of a repolarizing K + channel Risk of sudden death There are no identifiable gross abnormalities; disease involves the ion channels, resulting in repolarization abnormalities Ventricular arrhythmias develop at 12–16 weeks of age, and the frequency and severity of the arrhythmias increase until 24–30 weeks of age After 8 months of age, the arrhythmia severity stabilizes or starts to decrease Risk o

Comments • • • • • • the arrhythmia • age •

ECG characteristics Prolonged QT duration • QT>260–270 msec; QTc> • 304–314 msec T wave morphology is biphasic • Large variation in ECG findings • ranging from few VPCs to sustained and rapid polymorphic VT VPCs and VT • In some dogs, atrial premature • beats and second-degree AV nodal block present No QT interval prolongation •

Mutation in the KCNQ1 (Ware Inheritance is polygenic due to an abnormality in a major gene Ventricular arrhythmias inherited in an autosomal recessive mode and linked to mutations in the QIL1 gene, which is involved in mitochondrial function
Box 4.1 (Continued) Breed-specific arrhythmias

Genetics • et al. 2015) gene Inherited VT • • with modifiers •

Breed English Springer Spaniels German Shepherds Rhodesian Ridgebacks (Meurs et al. 2016)

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