title: Interventional cardiology for the criticalist.
abstract: OBJECTIVE
  To review indications, procedures, and prognosis for common cardiovascular emergencies requiring intervention in small animals.
  
  
  BACKGROUND
  Pericardial effusion, symptomatic bradycardia, and heartworm-induced caval syndrome are examples of clinical scenarios commonly requiring intervention. Pericardial effusion in small animals occurs most frequently from cardiac neoplasia, idiopathic pericarditis, or congestive heart failure. Indications for temporary pacing include transient bradyarrhythmias, ingestions resulting in chronotropic incompetence, and emergency stabilization of critical bradyarrhythmias. Caval syndrome results from a large dirofilarial worm burden, pulmonary hypertension, and mechanical obstruction of right-sided cardiac output with resultant hemolysis and organ dysfunction.
  
  
  METHODS
  The diagnosis of pericardial effusion is suspected from signalment and physical findings and confirmed with cardiac ultrasound. Symptomatic bradycardias often present for syncope and definitive diagnosis derives from an ECG. Caval syndrome is diagnosed upon clinical, hematologic, and ultrasonographic evidence of severe heartworm infestation, cardiovascular compromise, and/or mechanical hemolysis.
  
  
  METHODS
  Pericardial effusion is alleviated by pericardiocentesis in the emergency setting, though may require further intervention for long-term palliation. Temporary transvenous pacing can be performed emergently to stabilize the symptomatic patient with a bradyarrhythmia. Dirofilariasis leading to caval syndrome requires urgent heartworm extraction.
  
  
  CONCLUSIONS
  The prognosis for pericardial effusion is dependent upon the underlying etiology; the prognosis for cardiac pacing is favorable, and the prognosis for caval syndrome is grave if untreated and guarded to fair if heartworm extraction is performed.
authors.affiliation: Department of Veterinary Clinical Sciences, College of Veterinary Medicine, The Ohio State University, Columbus, OH 43210, USA. brian.scansen@cvm.osu.edu
authors.forename: Brian A
authors.initials: BA
authors.lastname: Scansen
mesh_terms: D000818:Animals; D002318:Cardiovascular Diseases / Q000175:diagnosis / Q000628:therapy / Q000662:veterinary*; D002371:Cat Diseases / Q000175:diagnosis* / Q000628:therapy*; D002415:Cats; D004184:Dirofilariasis / Q000175:diagnosis / Q000628:therapy; D004283:Dog Diseases / Q000175:diagnosis* / Q000628:therapy*; D004285:Dogs; D004632:Emergency Medical Services; D010490:Pericardial Effusion / Q000175:diagnosis / Q000628:therapy / Q000662:veterinary; D011379:Prognosis; D016896:Treatment Outcome; D014730:Veterinary Medicine / Q000295:instrumentation / Q000379:methods