Evaluation of left ventricular dimension and systolic function by standard transthoracic echocardiography before and 24-hours after percutaneous closure of patent ductus arteriosus in 120 dogs

A Retrospective Cohort Evaluation of Left Ventricular Remodeling, Perioperative Complications and Outcome in Medium and Large Size Dogs with Patent Ductus Arteriosus after Percutaneous Closure

This retrospective cohort study included one hundred fifty-seven medium and large-size dogs with the aim of evaluating the effect of signalment and echocardiographic features on complications, outcomes and left ventricular modifications before and after patent ductus arteriosus (PDA) closure. The patients were divided in two groups based on the heart remodeling after closure: Group A included dogs that had a reduction in the end-systolic volume index (ESVI) after closure compared to the ESVI measured before; Group B included dogs without a reduction in ESVI after closure. Body weight, minimal ductal diameter (MDD) of PDA, end-diastolic volume index and presence of arrhythmias at presentation were significantly higher in Group B compared to Group A. The shortening fraction and ejection fraction after closure were reduced in both groups, but in Group B there was a major reduction, and the mean values indicated a possible systolic dysfunction. Complications during the procedure and death due to cardiac reasons were greater in Group B compared to Group A. In conclusion, a higher body weight, a larger MDD, a more severe heart enlargement or arrhythmias at presentation increased the risk of developing a worsening structural and functional condition after ductal closure, and this can be associated with perioperative complications and cardiac death.

Conventional and advanced echocardiographic assessment of systolic function in dogs sedated with dexmedetomidine or acepromazine

Dexmedetomidine and acepromazine, sedatives commonly used in dogs have opposite vascular effects, resulting in afterload increase and decrease, respectively. This could variably affect systolic myocardial function. Previous echocardiographic studies assessing the cardiovascular effects of these drugs used conventional echocardiography, while advanced techniques such as speckle tracking echocardiography (STE) and tissue Doppler imaging (TDI), which are known to provide a more accurate assessment of systolic function, have been rarely used for this aim. Moreover, in the few studies using advanced techniques, the drugs where combined with opioids. Therefore, the main objective of this prospective study was to assess systolic myocardial function by conventional and advanced echocardiography (STE and TDI), in dogs sedated exclusively with dexmedetomidine or acepromazine not combined with other drugs. Twenty healthy dogs were randomly divided into two groups, Group A (acepromazine, 20 μg/kg IM), and Group D (dexmedetomidine, 5 μg/kg IM), cardiovascular parameters were assessed before sedation (T0), and thirty minutes afterwards (T1). Systolic arterial pressure and heart rate decreased in both groups at T1 as compared to T0. Only one conventional echocardiographic raw variable (left ventricular internal dimension in systole) and three out of five advanced echocardiographic variables (radial TDI systolic velocities at the epicardial region of the left ventricular free wall, longitudinal TDI systolic velocities of the septal mitral valve annulus and the STE-derived left ventricular global strain), were affected in Group D. A systolic impairment was observed in Group D and better estimated by advanced echocardiography. In Group A, only the end diastolic voume index (conventional echocardiography) was decreased. Both protocols seem to induce echocardiographic changes more likely secondary to their vascular action.

Echocardiographic Findings in Canine Model of Chagas Disease Immunized with DNA Trypanosoma cruzi Genes

Chagas disease (ChD) is considered an emerging disease in the USA and Europe. Trypanosoma cruzi genes encoding a trans-sialidase protein and an amastigote-specific glycoprotein were tested as vaccines in canine model. The aim for this study was determining the prophylactic effect of these genes in experimentally infected dogs by echocardiography evaluation to compare with our findings obtained by other techniques published previously. Low fractional-shortening values of non-vaccinated dogs suggested an impairment in general cardiac function. Low left ventricular ejection fraction values found in infected dogs suggested myocardial injury regardless of whether they were vaccinated. Low left ventricular diastolic/systolic diameters suggested that progressive heart damage or heart dilation could be prevented by DNA vaccination. Systolic peak time was higher in non-vaccinated groups, increasing vulnerability to malignant arrhythmias and sudden death. High left ventricular volume suggested a decrease in wall thickness that might lead to increased size of the heart cavity, except in the pBCSP plasmid-vaccinated dogs. There was an echocardiographic evidence of left ventricular dilation and reduction in systolic function in experimental chagasic dogs. Echocardiography allowed a more complete follow-up of the pathological process in the living patient than with other techniques like electrocardiography, anatomopathology, and histopathology, being the method of choice for characterizing the clinical stages of ChD.