title: Left ventricular thrombus development during ventricular fibrillation and resolution during resuscitation in a swine model of sudden cardiac arrest.
abstract: BACKGROUND
  Intracardiac thrombus is a well-known complication of low-flow cardiac states including acute myocardial infarction and atrial fibrillation. Little is known, however, about the formation of intracardiac (left ventricular [LV]) thrombus during the extreme low-flow state of cardiac arrest.
  
  
  OBJECTIVE
  Using a swine model of sudden cardiac arrest, we examined the sonographic development of LV thrombus over time after induction of ventricular fibrillation (VF) and resolution of thrombus with cardiopulmonary resuscitation (CPR).
  
  
  METHODS
  This observational study was IACUC approved. Forty-five Yorkshire swine were sedated, intubated, and instrumented under general anesthesia before VF was electrically induced. Sonographic data was collected immediately after VF induction and at 2-min intervals thereafter. Following 12min of untreated VF, resuscitation was initiated with closed chest compressions using an oxygen-powered mechanical resuscitation device. Observations were continued during attempted resuscitation. At the end of the experiment, the animals were euthanized while still at a surgical depth of anesthesia. The data was analyzed descriptively.
  
  
  RESULTS
  Sonographic evidence of LV thrombus was observed in 43/45 animals (95.6% [95%CI: 85.2%, 98.8%]). Thrombus was detected within 6min in 39/45 (86.7% [95%CI: 73.8%, 93.8%]) animals that developed thrombus. Thrombus resolved within 2min after initiation of chest compressions in 31/43 (72.1% [95%CI: 57.3%, 83.3%]) animals.
  
  
  CONCLUSIONS
  Similar to other low-flow cardiac states, LV thrombus develops early in the natural history of VF arrest and resolves quickly once forward flow is re-established by chest compressions. Institutional protocol number: 154600-8.
authors: Tufts University School of Medicine, Department of Emergency Medicine, Baystate Medical Center, 759 Chestnut Street, Springfield, MA 01199, United States. Electronic address: gavin.budhram@gmail.com.
authors: Gavin R
authors: GR
authors: Budhram
authors: Tufts University School of Medicine, Department of Emergency Medicine, Baystate Medical Center, 759 Chestnut Street, Springfield, MA 01199, United States.
authors: Timothy J
authors: TJ
authors: Mader
authors: Tufts University School of Medicine, Department of Emergency Medicine, Baystate Medical Center, 759 Chestnut Street, Springfield, MA 01199, United States.
authors: Lucienne
authors: L
authors: Lutfy
authors: Tufts University School of Medicine, Department of Emergency Medicine, Baystate Medical Center, 759 Chestnut Street, Springfield, MA 01199, United States.
authors: David
authors: D
authors: Murman
authors: Tufts University School of Medicine, Department of Emergency Medicine, Baystate Medical Center, 759 Chestnut Street, Springfield, MA 01199, United States.
authors: Abdullah
authors: A
authors: Almulhim
mesh_terms: D000818:Animals; D016887:Cardiopulmonary Resuscitation / Q000379:methods*; D003328:Coronary Thrombosis / Q000000981:diagnostic imaging / Q000209:etiology* / Q000503:physiopathology / Q000628:therapy*; D004195:Disease Models, Animal; D004452:Echocardiography; D006323:Heart Arrest / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*; D013552:Swine; D014693:Ventricular Fibrillation / Q000150:complications* / Q000000981:diagnostic imaging / Q000503:physiopathology / Q000628:therapy*
keywords: Cardiac arrest; Echocardiography; Intracardiac thrombus; Left ventricular thrombus; Ultrasound; Ventricular fibrillation