Cardiotoxic effects of pavetamine extracted from Pavetta harborii in the rat.

Previous studies have shown that crude extracts from Pavetta harborii as well as dried plant material have cardiotoxic effects on rats and sheep that can lead to heart failure. The active component has since been isolated and identified. This substance has been named pavetamine. The aim of this study was to determine whether pavetamine has cardiotoxic effects similar to those seen in previous reports, when administered to rats intraperitoneally. Sprague Dawley rats received two doses, initially 4 mg/kg and then 3 mg/kg pavetamine respectively and were monitored for 35 days before cardiodynamic parameters were measured by inserting a fluid-filled catheter into the left ventricle via the right carotid artery. These values were compared to those of control rats that had received only saline. Pavetamine significantly reduced systolic function and body mass in the treated rats, which indicates that it has the potential to induce heart failure in this animal model.

Foreign-body granulomas within intramyocardial arteries in a transcoronary safety assessment in pigs.

Foreign-body granulomas within intramyocardial arteries were detected in three domestic pigs (Sus scrofa domestica) in a routine transcoronary safety assessment study. The foreign bodies stained light grayish-blue by hematoxylin and eosin (H&E) and were strongly birefringent by polarized light microscopy. By their morphological features, they were identified as cotton fibers. Embolization of foreign-body material into the myocardial arteries following catheter-based procedures is an unusual event, and its occurrence may lead to granulomatous foreign-body reaction and misinterpretation of histological results.

Long-term palliation of tetralogy of Fallot in dogs by use of a modified Blalock-Taussig shunt.

OBJECTIVE: To describe a modified Blalock-Taussig shunt (mBT) procedure and assess its use in dogs with clinical signs associated with tetralogy of Fallot (TOF). DESIGN: Descriptive report. ANIMALS: 6 dogs with severe TOF-associated clinical signs. PROCEDURES: Each dog had TOF (confirmed echocardiographically or angiographically) and underwent an mBT shunt procedure for surgical palliation of signs. The surgery was performed through a left fourth rib resection or a left fifth intercostal thoracotomy. The left subclavian artery was dissected free from surrounding mediastinal tissue. The main pulmonary artery trunk was exposed through an incision in the overlying pericardium. A shunt comprised of a 6-mm-diameter tube of expanded polytetrafluoroethylene (5 dogs) or a segment of carotid artery (1 dog) was sutured end to side between the left subclavian artery and pulmonary artery trunk. RESULTS: 5 of the 6 dogs survived the immediate postoperative period. The dog that died shortly after surgery was the smallest of the dogs (weight, 2.9 kg [6.38 lb]) and had received the carotid artery autograft. Three dogs survived long term and 2 dogs died of unknown causes 6 years after undergoing the mBT shunt procedure. In all dogs that survived the mBT procedure, shunt patency was confirmed and quality of life appeared improved. CONCLUSIONS AND CLINICAL RELEVANCE: These findings have suggested that the mBT shunt procedure safely provides long-term palliation of TOF-associated clinical signs in dogs. In addition, it may offer an effective low-risk and lower-cost alternative to open heart repair of TOF.