Echocardiographic parameters in 50 healthy English bulldogs: preliminary reference intervals

Introduction/objectives: The objective of the study was to provide echocardiographic reference intervals for English bulldogs (EBs) and to assess if age, sex, body weight (BW), and heart rate have an influence on echocardiographic variables. Animals: We prospectively enrolled client-owned EBs that were considered healthy based on unremarkable history, normal physical examination, six-lead electrocardiography, and transthoracic echocardiography. Materials and methods: Breed-related reference intervals were provided, and associations between age, sex, BW, and heart rate and echocardiographic variables were tested using a multivariate analysis. Allometric scales were generated for echocardiographic variables showing correlation with BW. Moreover, echocardiographic variables obtained in our population of EBs and previous published reference ranges were compared. Results: Echocardiographic reference intervals were generated from 50 healthy adult EBs. As per the multivariate analysis, left atrial diameter (p = 0.015), left ventricular internal end diastolic diameter (p = 0.002), aortic valve annulus (p = 0.032), and pulmonary valve annulus (p = 0.017) resulted influenced by BW, and reference intervals were generated using allometric scales. Our study suggests that EBs tend to have a smaller aortic root and sphericity index than other breeds. In addition, EBs seem to have smaller indexed left ventricular volumes and higher left ventricular ejection fraction than boxers and Doberman. Conclusion: Preliminary reference intervals in the EBs are reported, which might be helpful for accurate echocardiographic interpretation and screening purposes in this breed

The Mitral INsufficiency Echocardiographic score: A severity classification of myxomatous mitral valve disease in dogs

Background: There is no commonly shared severity score for myxomatous mitral valve disease (MMVD) based on routinely acquired echocardiographic variables. Hypothesis/Objectives: To propose an easy-to-use echocardiographic classification of severity of MMVD in dogs. Animals: Five hundred and sixty dogs with MMVD. Methods: This was a retrospective, multicenter, observational study. The proposed Mitral INsufficiency Echocardiographic (MINE) score was based on 4 echocardiographic variables: left atrium-to-aorta ratio, left ventricular end-diastolic diameter normalized for body weight, fractional shortening, and E-wave transmitral peak velocity. Specific echocardiographic cutoffs were defined based on previous prognostic studies on MMVD, and severity scores were assigned as follows: mild (score: 4-5), moderate (score: 6-7), severe (score: 8-12), late stage (score: 13-14). Results: Median survival time was significantly different (P <.05) between the proposed severity classes: mild (2344 days, 95% confidence interval [CI] 1877-2810 days), moderate (1882 days, 95% CI 1341-2434 days), severe (623 days, 95% CI 432-710 days), and late stage (157 days, 95% CI 53-257 days). A MINE score >8 was predictive of cardiac death (area under the curve = 0.85; P <.0001; sensitivity 87%, specificity 73%). In the multivariable analysis, all the echocardiographic variables of the MINE score were independent predictors of death because of heart disease (P <.001). Conclusions and Clinical Importance: The MINE score is a new easy-to-use echocardiographic classification of severity of MMVD, which has been proven to be clinically effective as it is associated with survival. This classification provides prognostic information and could be useful for an objective echocardiographic assessment of MMVD

Left shift of the ventricular mean electrical axis in healthy doberman pinschers

In canine electrocardiography, the reference interval of the ventricular mean electrical axis (MEA) is between +40° and +100°. MEA values in dogs can be influenced by the patient position as well as by the shape of the thorax. The aim of this study was to evaluate the MEA in healthy Doberman Pinschers, hypothesizing that some present a left shift of the MEA. In this retrospective study, 41 healthy, client-owned Doberman Pinschers were included. Echocardiography and standard six-lead ECG examination were performed in all dogs. The MEA was calculated using the isoelectric method. The morphology of the QRS complex and the Q/R ratio in lead II were also evaluated. The median MEA was +45° and ranged from -45° to +90°. MEA was deviated in 16/41 dogs (39%), all presenting a left axis deviation (range, -45° to + 30°). Age was significantly associated with the MEA (P=0.008), showing a negative linear correlation. A deep Q wave in lead II was present in 26/41 (63%) dogs. The Q/R ratio was higher in dogs presenting left shift of the MEA (0.66; range, 0.28-1.35) in comparison to dogs with a MEA within reference range (0.44; range, 0.04-0.73; P<0.001). In conclusion, a significant number of healthy Doberman Pinschers present a left shift of the MEA compare to the reference range, and dogs with MEA deviation show a higher Q/R ratio in lead II. This data should be considered when electrocardiographic evaluation is performed in Doberman Pinschers

Echocardiographic reference intervals of the dimensions of the main pulmonary artery and the right pulmonary artery: a prospective study in 269 healthy dogs

Introduction: No data are available on the echocardiographic reference intervals (RIs) for the main pulmonary artery (MPA) and right pulmonary artery (RPA) dimensions in a large sample of dogs. Therefore, we aimed to describe the echocardiographic RIs of the MPA and RPA dimensions in normal dogs. Animals, materials, and methods: 269 healthy dogs of different breeds, age and body weight (BW) were prospectively enrolled in this multicenter, observational study. The MPA diameter, RPA maximum diameter (RPAmax), and RPA minimum diameter (RPAmin) were measured from the right parasternal short axis view. Prediction intervals (PIs) for MPA, RPAmax and RPAmin were generated using allometric scales. Reference intervals (RI) of MPA indexed to the ascending aorta (MPA/AO), and RPAmax and RPAmin indexed to the aortic annulus (RPAmax/Aod and RPAmin/Aod), were defined. Results: A positive linear relationship between MPA, RPAmax, RPAmin and BW was evident after logarithmic transformation (R2 = 0.859, R2 = 0.787 and R2 = 0.725, respectively; P<0.0001). According to allometric scales, the PI for the MPA normalized for BW (MPA_N) was between 5.50 and 8.07, the PI for the RPAmax normalized for BW (RPAmax_N) was between 3.23 and 5.62, while the PI for the RPAmin normalized for BW (RPAmin_N) was between 1.62 and 3.30. The median MPA/AO was 0.92 (RI, 0.78-1.01), the median RPAmax/Aod was 0.70 (RI, 0.53-0.98) and the median RPAmin/Aod was 0.40 (RI, 0.29-0.61). Discussion and conclusions: The reported RIs of the MPA and RPA dimensions in normal dogs could increase the diagnostic accuracy of transthoracic echocardiography in the identification of pulmonary artery enlargement in dogs

Clinical and Electrocardiographic Findings for Predicting the Severity of Pulmonary Valve Stenosis in Dogs

Pulmonary valve stenosis (PS) in dogs is usually suspected due to the presence of a heart murmur and clinical signs. Echocardiography is needed to confirm the diagnosis and define the severity of PS. This retrospective study evaluated the utility of clinical and electrocardiographic (ECG) findings in the prediction of PS severity. Data regarding heart murmur and ECG analysis were gathered. Ninety-seven dogs with PS were included. A murmur grade ≥IV/VI was predictive of severe PS (area under curve (AUC) = 0.71; sensitivity (Se) = 95%; specificity (Sp) = 33%; p = 0.003). In lead II, P wave amplitude >0.35 mV (AUC = 0.67; Se = 31%; Sp = 100%; p = 0.038), Q wave < 0.15 mV (AUC = 0.70; Se = 70%; Sp = 59%; p = 0.0015), R wave < 0.87 mV (AUC = 0.66; Se = 67%; Sp = 69%; p = 0.006), and S wave > 0.37 mV (AUC = 0.80; Se = 72%; Sp = 85%; p < 0.0001) were predictive of severe PS. The extent of right deviation of the mean electrical axis of the QRS complex was correlated with the pulmonary pressure gradient (r = 0.648; p < 0.0001). In conclusion, a systolic murmur with intensity ≥IV/VI, a P wave amplitude >0.35 mV, low amplitude of Q and R waves, deep S waves in lead II, and right axis deviation of the QRS complex in a young dog are predictive of severe PS

Closure of an unusual morphology patent ductus arteriosus with a covered stent in a dog

Patent ductus arteriosus (PDA) with unusual morphology was diagnosed in a 3-year-old German shepherd presented for exercise intolerance. Two interventional PDA closure procedures with various Amplatzer devices and one surgical ligation were attempted to close the PDA. However, PDA closure failed with both methods due to the unusual morphology and the severe enlarged ductus ampulla. Therefore, the patient underwent an aortic covered stent placement, and successful closure of the PDA was achieved. Eight months after the procedure, the dog was free of clinical signs and no residual flow was identified through the PDA on transthoracic echocardiography. Moreover, computed tomography angiography demonstrated correct stent positioning, with no evidence of thrombus formation, damage to the stent, nor any aortic wall abnormalities. Aortic covered stent placement is a viable option in dogs with unusual PDA morphology

Closure of an unusual morphology patent ductus arteriosus with a covered stent in a dog

Patent ductus arteriosus (PDA) with unusual morphology was diagnosed in a 3-year-old German shepherd presented for exercise intolerance. Two interventional PDA closure procedures with various Amplatzer devices and one surgical ligation were attempted to close the PDA. However, PDA closure failed with both methods due to the unusual morphology and the severe enlarged ductus ampulla. Therefore, the patient underwent an aortic covered stent placement, and successful closure of the PDA was achieved. Eight months after the procedure, the dog was free of clinical signs and no residual flow was identified through the PDA on transthoracic echocardiography. Moreover, computed tomography angiography demonstrated correct stent positioning, with no evidence of thrombus formation, damage to the stent, nor any aortic wall abnormalities. Aortic covered stent placement is a viable option in dogs with unusual PDA morphology

Pulmonary vein to pulmonary artery ratio in healthy and cardiomyopathic cats

Introduction/objectives: Recognition of congestive heart failure (CHF) in dyspnoeic cats is crucial for correct intervention. The pulmonary vein (PV) to pulmonary artery (PA) ratio (PV/PA) has been proposed as an index that might help discriminate dogs suffering from CHF but has never been studied in cats. We sought to determine reference intervals for various PV and PA variables in healthy cats. We then examined these variables in cats with subclinical and clinical cardiomyopathies to determine their diagnostic utility in identifying CHF. Animals, materials and methods: We took a sample of 114 cats: 51 healthy cats, 32 subclinical cardiomyopathy affected cats and 31 cardiomyopathic cats with CHF. PV and PA were measured at the minimal and maximal diameters using M-mode images obtained from a modified right parasternal long axis view. The aorta (Ao) and left atrium were measured using two-dimensional imaging employing the right parasternal short axis view. Results: median PVmin/PAmin value in healthy cats was approximately 0.51 and the PVmax/PAmax value was 0.67. The median distensibility value of the vessels was 23% for \u394PA and 41% for \u394PV. Cats with CHF had higher PVmin/PAmin, PVmax/PAmax, PVmin/Ao, PVmax/Ao values and a smaller \u394PV value compared to subclinical and healthy cats (p < 0.0001). When evaluating the diagnostic performance of these variables (in cardiomyopathic cats), PVmin/PAmin and PVmin/Ao values had higher accuracy compared to the LA:Ao value when identifying cats with CHF. Conclusions: Our study provides reference values for PV and PA variables in cats. Moreover, PV/PA variables were better factors than LA:Ao for discriminating cardiomyopathic cats with and without CHF

Risk factors for atrial fibrillation in dogs with dilated cardiomyopathy

IntroductionAtrial fibrillation secondary to dilated cardiomyopathy (DCM) frequently affects large-breed dogs. The aim of the present study was to identify risk factors for the development of atrial fibrillation in dogs of different breeds with an echocardiographic diagnosis of DCM. MethodsIn this multicenter retrospective study, we searched the electronic databases of five cardiology referral centers for dogs with an echocardiographic diagnosis of DCM. A comparison of clinical and echocardiographic variables was performed between dogs developing atrial fibrillation and those not developing atrial fibrillation and the ability to distinguish between these two groups of dogs was evaluated by receiver operating characteristic curve analysis. Univariate and multivariable logistic regression analysis estimated the odds ratio (OR) with 95% confidence interval (CI) of developing atrial fibrillation. ResultsWe included 89 client-owned dogs with occult and overt echocardiographic DCM. Of these, 39 dogs (43.8%) had atrial fibrillation, 29 dogs (32.6%) maintained a sinus rhythm, and 21 dogs (23.6%) showed other cardiac arrhythmias. Left atrial diameter had high accuracy (area under the curve = 0.816, 95% CI = 0.719-0.890) to predict the development of atrial fibrillation at the cut-off of >4.66 cm. After multivariable stepwise logistic regression analysis, only increased left atrial diameter (OR = 3.58, 95% CI = 1.87-6.87; p < 0.001) and presence of right atrial enlargement (OR = 4.02, 95% CI = 1.35-11.97; p = 0.013) were significant predictors of atrial fibrillation development. DiscussionAtrial fibrillation is a common complication of DCM in the dog and is significantly associated with increased absolute left atrial diameter and right atrial enlargement