Effect of additional dimensions and views in the echocardiographic determination of 3-dimensional left ventricular volume in myxomatous mitral valve disease in dogs.

Background: Left ventricular (LV) volumes can be calculated from various linear, monoplane, and multiplane echocardiographic methods, and the same method can be applied to different imaging views. However, these methods and their variations have not been comprehensively evaluated against real-time 3-dimensional echocardiography (RT3D).

Hypothesis/objectives: To identify the LV volumetric approaches that produce the least bias and the best agreement with RT3D, and to assess interoperator reproducibility between an experienced and an inexperienced operator.

Electrocardiographic patterns of ventricular pre-excitation in dogs with right-sided accessory pathways.

Introduction: The aim of the study was to describe the electrocardiographic features of ventricular pre-excitation (VPE) patterns characterized by the presence of delta (δ) wave, short P-δQRS interval, wide δQRS complexes in dogs with right-sided accessory pathways.

Animals, Materials And Methods: Twenty-six dogs with a confirmed accessory pathways (AP) via electrophysiological mapping were included. All dogs underwent a complete physical examination, 12-lead ECG, thoracic radiography, echocardiographic examination and electrophysiologic mapping.

Retrospective evaluation of hypertrophic cardiomyopathy in 68 dogs.

Background: There is a lack of clinical data on hypertrophic cardiomyopathy (HCM) in dogs.

Hypothesis/objectives: To investigate signalment, clinical signs, diagnostic findings, and survival in dogs with HCM.

Animals: Sixty-eight client-owned dogs.

Cardiac Disease of Raptors.

Cardiac disease, in its various presentations, is being recognized as a common raptor health problem. Evidence suggests that the prevalence of cardiac disease varies between captive and wild bird of prey populations, probably because of differences in activity levels and diet. However, a wide variety of cardiovascular diseases have been reported to affect raptor species (captive and free living), including atherosclerosis, pathogenic arrhythmias, infectious cardiomyopathies, and endocarditis.

Immunofluorescent Localization of Plakoglobin Is Altered in Endomyocardial Biopsy Samples from Dogs with Clinically Relevant Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC).

Diagnosing the early stages of canine Arrhythmogenic Right Ventricular Cardiomyopathy (ARVC) is complicated by day-to-day arrhythmia variability, and absence of reliable, transthoracic echocardiographic features. Definitive diagnosis requires histopathologic identification of transmural fibrofatty replacement of the right ventricle. Reduction of immunofluorescent signal for plakoglobin (PG) at the intercalated disc (ID) is reported in ARVC-affected humans and boxers.

Optimizing single-chamber pacing in dogs Part 1: Rate determinations, rate interventions and hysteresis.

Determining ideal pacing rates to meet physiological needs and optimizing programming to prevent unnecessary right ventricular pacing in dogs requires an understanding of heart rate profiles and applicable pacing technology. The heart rate and rhythm of the dog is complex necessitating investigation of rate requirements of activity and circadian influences. Overlaying this information are a multiplicity of other factors such as age, breed, temperament, cardiovascular disease and underlining rhythm disorders that contribute to the difficulty in making general conclusions.

Optimizing single-chamber pacing in dogs. Part 2: Rate adaptive pacing.

Proper programming of pacemakers for dogs in the rate adaptive mode requires an understanding of the rate requirements for each individual and the interplay of programmable features. The specific advantages and disadvantages of the rate adaptive mode should be considered on a case by case basis. Fundamentally, two components are linked in the implementation of rate adaptive pacing: (1) sensing the need for a change in rate and (2) responding with the appropriate alteration in pacing rate.

Resolution of caval syndrome during initial hemodynamic stabilization in dogs with heartworm disease.

Objective: To report on the spontaneous resolution of caval syndrome in 5 dogs selected for their response to medical stabilization prior to scheduled heartworm extraction.

Series Summary: Five dogs with heartworm caval syndrome were treated with sildenafil, fluid, and supplemental oxygen therapy. Moreover, 4 of 5 dogs were also administered pimobendan to achieve hemodynamic stabilization in preparation for percutaneous heartworm extraction.

Beat-to-Beat Patterning of Sinus Rhythm Reveals Non-linear Rhythm in the Dog Compared to the Human.

The human and dog have sinus arrhythmia; however, the beat-to-beat interval changes were hypothesized to be different. Geometric analyses (R-R interval tachograms, dynamic Poincaré plots) to examine rate changes on a beat-to-beat basis were analyzed along with time and frequency domain heart rate variability from 40 human and 130 canine 24-h electrocardiographic recordings. Humans had bell-shaped beat-interval distributions, narrow interval bands across time with continuous interval change and linear changes in rate.

Atrial Fibrillation: Current Therapies.

A rate control, or a rhythm control, strategy can be applied to the management of atrial fibrillation. Rate control of atrial fibrillation consists of decreasing the ventricular response rate by limiting the number of supraventricular impulses that can travel through the atrioventricular node. The goal of decreasing heart rate in dogs with atrial fibrillation is usually achieved with a combination of the calcium channel blocker diltiazem and digoxin.

COMPUTED TOMOGRAPHIC MEASUREMENT OF THE MAIN PULMONARY ARTERY TO AORTIC DIAMETER RATIO IN HEALTHY DOGS: A COMPARISON TO ECHOCARDIOGRAPHICALLY DERIVED RATIOS.

Indicators of pulmonary hypertension in dogs examined with thoracic computed tomography (CT) are not well established in the veterinary literature. In humans, the main pulmonary artery to aortic diameter ratio (MPA:Ao) measured via CT, has been shown to be more sensitive than echocardiographic variables for predicting presence and severity of pulmonary hypertension, in some cases. In veterinary literature, the MPA:Ao has been determined echocardiographically to have an upper limit of about 1:1.

Fungal myocarditis and pericardial effusion secondary to Inonotus tropicalis (phylum Basidiomycota) in a dog.

Fungal disease is a rare cause of pericardial effusion in dogs. This report describes the first case of fungal pericardial effusion and myocarditis secondary to the fungal organism Inonotus tropicalis. A 9-year-old female spayed French bulldog with a multi-year history of treatment with glucocorticoids for management of atopy was presented for exercise intolerance, ascites and weight loss.

Establishment of macrocyclic lactone resistant Dirofilaria immitis isolates in experimentally infected laboratory dogs.

Background: Strains of Dirofilaria immitis suspected of lack of efficacy (LOE) to macrocyclic lactone (ML) preventive drugs have been increasingly reported in dogs by practicing veterinarians since 2005 in the Lower Mississippi Delta region. If proven, and not controlled in the early stages, the emergence of ML drug resistance threatens to become a widespread problem in the US that may limit the effectiveness of current preventive drug treatment methods.

Methods: To validate practice reports, a statewide survey of Louisiana veterinarians was done to define the extent of the problem and identify focal 'hotspots' of reported ML LOEs using Geographic Information Systems (GIS) methods.

Effects of intramuscular sedation with alfaxalone and butorphanol on echocardiographic measurements in healthy cats.

Objectives: The aim of the study was to evaluate the effects of intramuscular (IM) injections of alfaxalone combined with butorphanol on echocardiographic (ECG) measurements in cats.

Methods: Client-owned adult domestic shorthair cats younger than 5 years of age were recruited. All cats that were considered healthy on the basis of physical examination, blood work, urinalysis, blood pressure measurement and baseline ECG underwent a second ECG under sedation.

Atrial septal pacing in small dogs: a pilot study.

Objective: To determine the feasibility of atrial septal pacing via a delivery catheter-guided small non-retracting helix pacing lead.

Animals: Six healthy beagles (8.3-12.

Outcome of a heartworm treatment protocol in dogs presenting to Louisiana State University from 2008 to 2011: 50 cases.

Since 2008, the American Heartworm Society has recommended using a three-dose melarsomine protocol (a single intramuscular injection of melarsomine dihydrochloride at 2.5mg/kg, followed approximately 1 month later with two doses administered 24h apart) for all heartworm-positive dogs, with doxycycline given at 10mg/kg twice daily for 4 weeks prior to administration of melarsomine. To report the efficacy and side effects of this standard heartworm treatment protocol in 50 dogs presenting to our hospital from 2008 to 2011, information on the history, clinical, laboratory, and diagnostic imaging findings and treatment was obtained from medical records.

Comparison of cardiac output determined by an ultrasound velocity dilution cardiac output method and by the lithium dilution cardiac output method in juvenile horses with experimentally induced hypovolemia.

Objective: To assess the accuracy of an ultrasound velocity dilution cardiac output (UDCO) method, compared with that of the lithium dilution cardiac output (LiDCO) method, for determination of cardiac output (CO) in juvenile horses with experimentally induced hypovolemia.

Animals: 12 anesthetized 2- to 6-month-old horses.

Procedures: For each anesthetized horse, CO was determined by the LiDCO and UDCO methods prior to any intervention (baseline state), after withdrawal of approximately 40% of the horse's blood volume (low CO state), after maintenance of hypovolemia and infusion of norepinephrine until mean arterial blood pressure was equal to baseline value (high CO state), and after further infusion of norepinephrine and back-transfusion of withdrawn blood (posttransfusion state).

Transthoracic lung ultrasound in normal dogs and dogs with cardiogenic pulmonary edema: a pilot study.

Pulmonary edema is the most common complication of left-sided heart failure in dogs and early detection is important for effective clinical management. In people, pulmonary edema is commonly diagnosed based on transthoracic ultrasonography and detection of B line artifacts (vertical, narrow-based, well-defined hyperechoic rays arising from the pleural surface). The purpose of this study was to determine whether B line artifacts could also be useful diagnostic predictors for cardiogenic pulmonary edema in dogs.

Shunting between the CVC and both the azygos vein and thoracic duct in a dog with CTD.

A 5 mo old female rottweiler was referred for evaluation of a suspected congenital heart disease. Clinical signs included anorexia, exercise intolerance, and severe loss of body condition. Clinical examination revealed dyspnea, pale mucous membranes, and weak femoral pulses.

Comparison of transcoelomic, contrast transcoelomic, and transesophageal echocardiography in anesthetized red-tailed hawks (Buteo jamaicensis).

Objective: To assess the agreement and reliability of cardiac measurements obtained with 3 echocardiographic techniques in anesthetized red-tailed hawks (Buteo jamaicensis).

Animals: 10 red-tailed hawks.

Procedures: Transcoelomic, contrast transcoelomic, and transesophageal echocardiographic evaluations of the hawks were performed, and cineloops of imaging planes were recorded.

Evaluation of shock waveform configuration on the defibrillation capacity of implantable cardioverter defibrillators in dogs.

Background: Implantable cardioverter defibrillators (ICD) are programmed to detect ventricular arrhythmias and terminate them by delivering an electrical shock. A defibrillation threshold (DFT) at least 10 J below the maximum device output is recommended for successful therapy. Shock waveform configuration is a programmable parameter used to achieve a low DFT.