Cardiovascular images: pacemaker-lead fracture and excessive coiling in a dog.

A seven-year-old male castrated Labrador Retriever presented emergently due to concern for pacemaker malfunction five years after successful transvenous pacemaker implantation to treat partial atrial standstill. On presentation, the dog's pulse rate was 30-50 beats per minute. An electrocardiogram showed no spontaneous atrial activity or paced ventricular activity. Pacemaker interrogation revealed an increased impedance of 7557 ohms, indicating a lead malfunction. Thoracic radiographs confirmed the lead was fractured and had excessive coiling. The transvenous pacing system was turned off, left in place, and an epicardial pacing system was implanted the following day. The dog was discharged with no perioperative complications. The dog eventually required escalated medical therapy for progressive cardiac disease and was euthanized two years after implantation of the replacement pacemaker. This manuscript illustrates a complete lead fracture and excessive lead coiling, which has not previously been detailed in veterinary medicine.

Echocardiographic caudal vena cava measurements in healthy cats and in cats with congestive heart failure and non-cardiac causes of cavitary effusions.

BACKGROUND: Echocardiographic indices of the inferior vena cava have been associated with elevated right atrial pressures in humans. HYPOTHESIS/OBJECTIVES: Describe caudal vena caval (CVC) sonographic dimensions in healthy cats compared to cats with cardiogenic cavitary effusion (CCE), cardiogenic pulmonary edema (CPE), or non-cardiac causes of cavitary effusion (NCE). ANIMALS: 30 healthy control cats and 52 client-owned cats with CCE, CPE, or NCE examined at two university hospitals. METHODS: Sagittal 2-dimensional (2D) and M-mode CVC dimensions were acquired from the subxiphoid view. Caudal vena cava collapsibility index (CVC-CI) was calculated. Variables were compared between study groups using Kruskal-Wallis and Dunn's Bonferroni testing. Receiver operating characteristic curves were used to assess sensitivity and specificity for diagnostic categories. RESULTS: Healthy cats had sagittal 2D and M-mode (median, interquartile range) CVC maximal dimensions of 2.4 mm (1.3-4.0) and 3.4 mm (1.5-4.9) and CVC-CI of 52% (45.2-61.8) and 55% (47.8-61.3), respectively. The CVC maximal dimensions in healthy controls were smaller than in cats with cavitary effusions or pulmonary edema (all P<0.05). CVC-CI was different between CCE and NCE (P<0.0001) with cutoffs of CVC-CI ≤38% (2D) or ≤29% (M-mode) being 90.5% and 85.7% sensitive, and 94.4% and 100% specific for diagnosis of CCE, respectively. CONCLUSIONS AND CLINICAL IMPORTANCE: Caudal vena cava measurements are larger in cats with cavitary effusions and cats with CPE than healthy cats. In cats with cavitary effusion, decreased CVC-CI, ≤38% (2D) or ≤29% (M-mode), was helpful in distinguishing between cardiogenic and noncardiogenic etiology.

Association of diet with clinical outcomes in dogs with dilated cardiomyopathy and congestive heart failure.

INTRODUCTION: Dilated cardiomyopathy (DCM) in dogs has been associated with feeding of grain-free (GF), legume-rich diets. Some dogs with presumed diet-associated DCM have shown improved myocardial function and clinical outcomes following a change in diet and standard medical therapy. HYPOTHESIS: Prior GF (pGF) diet influences reverse cardiac remodeling and clinical outcomes in dogs with DCM and congestive heart failure (CHF). ANIMALS AND METHODS: A retrospective study was performed with 67 dogs with DCM and CHF for which diet history was known. Dogs were grouped by diet into pGF and grain-inclusive (GI) groups. Dogs in the pGF group were included if diet change was a component of therapy. Survival was analyzed using Kaplan-Meier curves and the Cox proportional-hazards model. RESULTS: The median survival time was 344 days for pGF dogs vs. 253 days for GI dogs (P = 0.074). Statistically significant differences in median survival were identified when the analysis was limited to dogs surviving longer than one week (P = 0.033). Prior GF dogs had a significantly worse outcome the longer a GF diet was fed prior to diagnosis (P = 0.004) or if they were diagnosed at a younger age (P = 0.017). Prior GF dogs showed significantly greater improvement in normalized left ventricular internal diastolic diameter (P = 0.038) and E-point septal separation (P = 0.031) measurements and significant decreases in their furosemide (P = 0.009) and pimobendan (P < 0.005) dosages over time compared to GI dogs. CONCLUSIONS: Prior GF dogs that survived at least one week after diagnosis of DCM, treatment of CHF, and diet change had better clinical outcomes and showed reverse ventricular remodeling compared to GI dogs.