ELECTROCARDIOGRAPHIC FINDINGS IN BITCHES AFFECTED BY CLOSED PYOMETRA

Pyometra is the commonest disorder of reproductive tract affecting intact bitches over 8 years old [1]. Clinical signs are associated to accumulation of purulent fluid in the uterus and, in severe cases, to the onset of endotoxemia, sepsis and systemic multiorgan inflammation. A fatal outcome it is observed in the 4% of patients[2]. Myocarditis is a common complication of the pyometra, and it is suspected to be a contributing factor to unexpected deaths [3]. However, scare information are available on the cardiac electric disorder in course of pyometra; therefore aims of the present study were (i) to describe the electrocardiographic findings; (ii) to assess the clinical relevance of electrocardiographic changes. Thirty-nine bitches belonging to different breeds and aging between 4 and 13 years old (mean 8.4 years old) with diagnosis of closed pyometra were included. The suspect of pyometra was performed on basis of oestrus cycle (luteal phase), clinical signs, laboratory findings and abdominal ultrasound examination. All bitches were underwent to electrocardiographic evaluation before the surgical treatment. Briefly, a six lead ECG was recorded using 25 and 50 mm/sec paper speed and 1 cm =1mV for 20-30 seconds. The following electrocardiographic changes were recorded: low R-amplitude in (17/39, 43.8%) ventricular premature complexes in (9 out of 39, 23%), large T (7/39, 7.9 %), ST depression and coving ( 4/39, 10.2 %). No ECG abnormalities were found in 5 cases (12.8 %). ECG findings observed were differently associated to mechanical factors or presence of systemic disorders. Precordial low voltage of R-wave was observed in humans affected with ascites [4]. Changes had been mostly attributed to the effect of generalized fluid retention for a shift of the anatomical heart axis in response to the abdominal pressure. The occurrence of ventricular extrasystoles and alterations of ST tract may be related to endotoxemia. In fact, it has been documented that the presence of endotoxins into the circulation may be determine systemic of inflammation, and in any cases myocardial cellular damage [5]. In 7/9 bitches presenting ventricular extrasystoles was observed leucocytosis with a left shift, neutrophilia, monocytosis, increased globulins, reflecting systemic inflammatory response. In humans, ST depression and T abnormalities were observed in ECG of patient with myocardial ischemia. Myocardial injury may presented secondary to endotoxemia, disseminated bacterial infection and is considered a factor contributing to unexpected death in course of pyometra. The safest and most effective treatment of pyometra is ovarysterectomia. Surgery and anaesthesia may cause myocardial ischemia, with consequent myocardial cell damage, especially in subjects with suspected systemic inflammation. In accordance with the presented results ECG evaluation before the surgery may be essential on the correct management of bitches affecting by pyometra.