StarCare Animals
When cats develop hypertrophic cardiomyopathy (HCM), their electrocardiograms (ECGs) show specific changes. Hypertrophic cardiomyopathy is a disease that manifests itself primarily as a thickening of the left ventricular wall and can affect approximately 15% of cats, with Maine Coon and Ragdoll cats in particular being more susceptible due to genetic factors.
An electrocardiogram is an important diagnostic tool for assessing a cat's heart health and can identify heart problems including hypertrophic cardiomyopathy. The following are ECG features associated with hypertrophic cardiomyopathy:
1. enlargement pattern: this is characterized by an R-wave height of more than 0.9 mV and sometimes a prolonged QRS interval of more than 0.045 seconds.
2. electrical axis shift: this is a typical feature of hypertrophic cardiomyopathy and usually manifests as a positive R wave in lead I and a deep S wave in leads II, III and aVF. This condition may suggest left ventricular enlargement or left anterior bundle block.
3. Conduction disturbances and arrhythmias: Cats with hypertrophic cardiomyopathy may present with conduction disturbances and arrhythmias, the exact type and severity of which vary from individual to individual. The ambulatory electrocardiogram is the main diagnostic tool.
4. Ischemia and infarction: In some cases of hypertrophic cardiomyopathy, myocardial ischemia or infarction may occur, and the ST-T segment of the electrocardiogram may show corresponding changes.
These ECG findings should be evaluated in conjunction with other diagnostic tools such as echocardiography. Echocardiography can accurately measure ventricular wall thickness and left atrial size. In addition, physical examination, history, clinical presentation, and other tests (e.g., blood pressure and thyroid function tests) are important components in the diagnosis and assessment of the severity of feline hypertrophic cardiomyopathy.
In summary, the ECG is one of the key tools in the detection and evaluation of feline hypertrophic cardiomyopathy but should be used as part of a broader diagnostic measure in conjunction with other tests and assessment methods to confirm the diagnosis of the disease and its severity.
Reference
College of Veterinary Medicine, NC State University, Cardiology: Feline Hypertrophic Cardiomyopathy, Cardiology: Feline Hypertrophic Cardiomyopathy | Veterinary Hospital (ncsu.edu), 2023
Hoskins, JD, ECG remains key diagnostic for cardiomyopathy in cats, www.dvm360.com/view/ecg-remains-key-diagnosticfor-cardiomyopathy-cats , November 2003
Hypertrophic cardiomyopathy (HCM) in cats is a thickening of the heart muscle （https://www.kingsdale.com/hypertrophic-cardiomyopathy-hcm-in-cats ）.
Left anterior fascicular block in a cat with hypertrophic cardiomyopathy. Typical features include a left axis deviation with a qR configuration in lead I, and deep S waves in leads II, III, and aVF (https://www.vin.com/apputil/content/defaultadv1.aspx?meta=&pId=11149&id=3846601 )
