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Published on: February 17, 2018
Clinical signs associated with severe ST segment elevation in three cats with a hypertrophic cardiomyopathy phenotype
J Seo1, T A Kurosawa2, K Borgeat3
1Animal Referral Centre (ARC Central), 8 Hereford Street, Freemans Bay, Auckland 1011, New Zealand; School of Veterinary Science, Massey University, Tennent Drive, Palmerston North 4410, New Zealand.
Insights
This case series highlights severe ST elevation in cats with hypertrophic cardiomyopathy (HCM). Continuous ECG monitoring revealed transient ST elevation coinciding with collapse, often linked to cardiac lymphoma or HCM complications.
Area of Science:
- Veterinary Cardiology
- Comparative Pathology
Background:
- Hypertrophic cardiomyopathy (HCM) is a common cardiac disease in cats.
- Unusual collapsing episodes in cats can indicate serious underlying cardiac pathology.
Observation:
- Three cats with collapsing episodes showed a hypertrophic cardiomyopathy (HCM) phenotype on echocardiography.
- Continuous electrocardiographic (ECG) monitoring revealed severe ST-segment elevation coinciding with clinical signs in all cats.
- Postmortem examination in one cat revealed cardiac lymphoma, not obstructive coronary disease.
Findings:
- Two cats were diagnosed with cardiac lymphoma, one with HCM and left ventricular outflow tract obstruction.
- Treatment outcomes were poor, with all three cats eventually euthanized due to disease progression or complications.
- Severe ST elevation on ECG was a key finding associated with these severe cardiac conditions.
Implications:
- This case series underscores the importance of continuous ECG monitoring for diagnosing transient ST elevation in cats presenting with collapsing episodes and an HCM phenotype.
- Early detection and accurate diagnosis are critical for managing feline cardiac diseases, although outcomes in these severe cases were poor.
- Further research into the causes and treatments of ST elevation in cats with HCM is warranted.
Abstract:
Three cats were presented for unusual collapsing episodes. Echocardiography revealed a hypertrophic cardiomyopathy (HCM) phenotype in each cat. Continuous electrocardiographic monitoring showed that the clinical signs coincided with periods of severe ST-segment elevation in each cat. The first cat was treated with amlodipine and diltiazem but did not improve and was euthanized due to poor quality of life. Postmortem examination revealed cardiac lymphoma without obstructive coronary disease. The second cat was thought to have cardiac lymphoma, based on pericardial effusion cytology, and was euthanized before starting therapy. The third cat was diagnosed with HCM and left ventricular outflow tract obstruction and was treated with atenolol and diltiazem. This treatment reduced the frequency of episodic clinical signs, but the cat subsequently developed congestive heart failure and was euthanized. This case series describes clinical signs associated with severe ST elevation in cats with an HCM phenotype, and their outcomes. Continuous electrocardiographic monitoring was necessary to detect transient ST elevation in each case.
