Heart Attack in Cats

PetMD Editorial
By PetMD Editorial on Feb. 12, 2010
Heart Attack in Cats

Myocardial Infarction in Cats


Much like in humans, a blockage of blood flow to the myocardium (the heart's muscular wall), is medically referred to as a heart attack, or myocardial infarction. This is generally due to the formation of a blood clot (or thrombus) within the blood vessels or heart, causing the premature death of a portion of the myocardium.


Heart attacks are rare in both cats and dogs.


Symptoms and Types


  • Weakness
  • Lethargy
  • Vomiting
  • Difficult breathing
  • Obesity
  • Low-grade fever
  • Lameness
  • Increased heart rate
  • Collapse
  • Sudden death




  • Cardiomyopathy
  • Thromboembolism




You will need to give a thorough history of your cat’s health, including the onset and nature of the symptoms. The veterinarian will then conduct a complete physical examination, paying close attention to the cat's cardiovascular system. Various laboratory tests -- such as complete blood count (CBC), blood culture biochemistry profile, and urinalysis -- will be used to help identify the underlying cause of the heart attack.


Blood testing may reveal an increased number of white blood cells (leukocytes), often seen during infections. The biochemistry profile, meanwhile, may show abnormally high levels of liver enzymes or abnormally low levels of T3 and T4 hormones. Echocardiography is another excellent tool used to evaluate of cardiac abnormalities.



The course of treatment will depend on the underlying cause of the heart attack and the complications associated with the myocardial infarction. Initial treatment also involves using medication(s) to dissolve the thrombus and restore blood flow to the heart muscles.


In severe cases, especially those with irregular heart rhythms, cats will hospitalized until they are stabilized. 

Living and Management


The prognosis largely depends on extent and duration of problem. In addition to regular monitoring of heart and laboratory testing during treatment, your veterinarian will recommend restricting the cat's activity during and after treatment.

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