Comparison of the effects of four antiarrhythmic treatments for familial ventricular arrhythmias in Boxers

OBJECTIVE: To evaluate the effect of 4 antiarrhythmic treatment protocols on number of ventricular premature complexes (VPC), severity of arrhythmia, heart rate (HR), and number of syncopal episodes in Boxers with ventricular tachyarrhythmias. DESIGN: Randomized controlled clinical trial. ANIMALS: 49 Boxers. PROCEDURE: Dogs with > 500 VPC/24 h via 24-hour ambulatory ECG (AECG) were treated with atenolol (n = 11), procainamide (11), sotalol (16), or mexiletine and atenolol (11) for 21 to 28 days. Results of pre- and posttreatment AECG were compared with regard to number of VPC/24 h; maximum, mean, and minimum HR; severity of arrhythmia; and occurrence of syncope. RESULTS: Significant differences between pre- and posttreatment number of VPC, severity of arrhythmia, HR variables, or occurrence of syncope were not observed in dogs treated with atenolol or procainamide. Significant reductions in number of VPC, severity of arrythmia, and maximum and mean HR were observed in dogs treated with mexiletine-atenolol or sotalol; occurrence of syncope was not significantly different between these 2 treatment groups. CONCLUSIONS AND CLINICAL RELEVANCE: Treatment with sotalol or mexiletine-atenolol was well tolerated and efficacious. Treatment with procainamide or atenolol was not effective.     

Utility of N-terminal pro-brain natriuretic peptide for assessing hemodynamic significance of patent ductus arteriosus in dogs undergoing ductal repair

ObjectiveDetermine if plasma N-terminal pro-brain natriuretic peptide (NT-proBNP) correlates with markers of hemodynamically significant patent ductus arteriosus (PDA) in dogs.AnimalsTen dogs with PDA and 30 healthy dogs of similar ages.MethodsProspective case series with control population. Dogs with PDA were initially evaluated with thoracic radiographs, transthoracic echocardiography, pulmonary capillary wedge pressure (PCWP) and NT-proBNP. Following ductal occlusion, NT-proBNP and echocardiography were repeated within 24 h and at day 90. PCWP was repeated at day 90. Correlation between NT-proBNP and hemodynamic measurements was assessed, and accuracy of NT-proBNP for identifying PDA severity was estimated.ResultsNT-proBNP was significantly higher (median; absolute range) in dogs with PDA (895; 490–7118 pmol/L) than controls (663; 50–1318 pmol/L) (p = 0.025). NT-proBNP decreased significantly 90 days post-ductal closure (597; 154–1858 pmol/L) (p = 0.013). Left atrial and ventricular size decreased significantly within 24 h and at day 90 as did PCWP (day 90 only). NT-proBNP correlated with vertebral heart size (VHS) and indexed left ventricular systolic diameter (iLVIDs); concentrations ≥ 1224 pmol/L distinguished dogs with elevated VHS and iLVIDs.ConclusionsNT-proBNP is elevated in dogs with PDA, decreases following PDA closure and correlates with select radiographic and echocardiographic markers of cardiac remodeling.     

Influence of locking bolt location on the mechanical properties of an interlocking nail in the canine femur

Objective: To determine whether the fatigue properties of an interlocking nail (ILN) construct are influenced by metaphyseal or diaphyseal location of the locking bolt. Study Design: Ex vivo mechanical investigation. Sample Population: Adult canine femora (n=19 pairs). Methods: Femora were implanted with a 6‐mm diameter ILN. In 1 femur, the ILN was locked with a 2.7 mm bolt placed in the diaphysis; the ILN in the contralateral femur was locked with a bolt placed in the metaphysis. Constructs were tested to failure in axial loading (9 pairs) or torsion (10 pairs), with failure defined as displacement>2 mm or a total of 500,000 cycles for axial loading, and rotation>45° for torsional loading. Outcome measures included initial construct stiffness, number of cycles to failure, peak load, and peak torque. After testing, microradiography and histology were used to determine the location and nature of construct failure. Results: Metaphyseal bolts failed at higher axial loads than diaphyseal bolts (P=.03), with bolt failure because of bending at the nail‐bolt interface. All of the metaphyseal bolt constructs survived torsional testing whereas 9 of 10 diaphyseal bolt constructs failed catastrophically because of spiral fracture through the adjacent cortical bone. Conclusions: Placement of a locking bolt in metaphyseal bone extends fatigue life under axial loading and decreases the incidence of catastrophic failure under torsional loading.     

Economic Impacts of the U.S. Gulf of Mexico Recreational For-Hire Fishing Industry

IMPLAN Version 3.0 was used with a 2008 IMPLAN data package to estimate the economic impacts of the recreational for-hire (RFH) fishing industry in the U.S. Gulf of Mexico (GOM). Initial, direct, indirect, and induced impacts were estimated. Impacts were estimated for head, charter, and guide boat operations for Texas, Louisiana, Mississippi, and Alabama (combined), and West Florida as individual state models, while introducing multiregional spillover effects that account for regional linkages between states. These updated data are necessary to meet national standards set forth by the Magnuson-Stevens Act, such that social and economic ramifications of proposed federal fishing regulations in the GOM can be made part of the overall decision- and policymaking process.     

Myocardial perforation by a stick foreign body in a dog

Objective: To report a case of myocardial perforation by a stick foreign body in a dog. Case Summary: A 3‐year‐old castrated male Labrador Retriever was examined because of a puncture wound seen after an unsupervised run in the woods. The wound was suspected to penetrate into the thoracic cavity on the basis of physical exam and radiographs. Uniform ventricular premature complexes (VPCs) and junctional beats were noted on electrocardiogram (ECG). Thoracotomy was performed and a 6‐cm wooden stick was seen protruding from the right ventricle through the pericardium toward the sternum. The stick was removed while purse string sutures were tied around the resultant myocardial defect. Follow‐up echocardiography revealed intact intracardiac structures. VPCs were treated with lidocaine and resolved completely within 24 hours of presentation. New or Unique Information Provided: Thoracic trauma can result in myocardial injury; penetration into the myocardium represents a life‐threatening situation for the emergency clinician. Cardiac injury should be included in the differential diagnoses of penetrating thoracic foreign bodies.