Constrictive pericarditis in a mare: attempted treatment by partial pericardiectomy.

This research article discusses a case of chronic, constrictive pericarditis in a young Thoroughbred mare and presents the results of an attempted treatment through partial pericardiectomy.

Diagnosis of Constrictive Pericarditis

• The study entails a detailed case of a six-year-old Thoroughbred mare that was diagnosed with chronic constrictive pericarditis.
• This diagnosis was based on several clinical indications that include the right congestive heart failure, a condition where the heart’s right side is unable to pump blood efficiently to the lungs.
• Other observed indicators leading to the diagnosis were the presence of a hyperechoic pericardium without pericardial effusion, showing an unusually bright echo in ultrasound confinement within the sac enveloping the heart, and devoid of excess buildup of fluid.
• A further supporting characteristic was a dip-and-plateau shape of the right ventricular pressure curve paired with matching diastolic pressures in all the heart chambers. This hint is typical in constrictive pericarditis where the stiff pericardium prevents the heart from expanding completely during relaxation phase (diastole) causing pressure to equalize.

Attempted Treatment: Partial Pericardiectomy

• The research team attempted a treatment method called partial pericardiectomy via a right lateral thoracotomy approach, which involves making an incision into the chest wall to access and remove a portion of the problematic pericardium surrounding the heart of the horse.
• Unfortunately, due to severe epicardial involvement, the recurrence of the constrictive pathology was observed six weeks after the surgery. This means that the disease affected not only the outer lining of the heart (pericardium) but also extended to the heart’s inner layer (epicardium), making the treatment less effective and leading to a resurgence of the disease.

Overall Conclusion and Implications

• Despite the unsuccessful treatment in this specific case, the researchers suggest that, in selected cases where the disease is confined only to the pericardium, partial pericardiectomy might still be a viable treatment option.
• This research indication can significantly aid equine veterinarians in devising suitable treatment plans for horses suffering from constrictive pericarditis, depending on the spread of the disease.