Ventricular arrhythmia (IVA)

In the breed Rhodesian Ridgeback, a genetic variant of the QIL1 gene has been found to be associated with a heart disease called ventricular arrhythmia (IVA). The QIL1 gene encodes for a protein that plays an important part in the placement and distribution of the mitochondrial cristae and therefore the cellular energy production. \n\nAffected dogs develop ventricular and/or supraventricular tachycardia and cardiac arrhythmia usually between the age of 6-18 months. In some cases, this could also lead to sudden cardiac death. The disease has a variable penetrance and expression. Therefore, many dogs carrying the variant do not develop arrhythmia or sudden death. About 60% of the dogs carrying the variant show abnormal heart beats and some dogs were documented to outgrow the abnormal beats. Dogs that have been testes as carriers for this variant should be regularly examined by a holter monitoring (24-hour electrocardiogram). \n\nThe genetic test identifies the carrier dogs in order to reduce the prevalence of the variant in the breed. However, this test is not able to provide any predictions whether a carrier dog will develop any symptoms of the disease or about the strength of the symptoms.