title: Esophageal assessments of left ventricular filling pressures: A proof-of-concept study.
abstract: OBJECTIVE
  We sought to evaluate if left ventricular filling pressures can be assessed from the esophagus.
  
  
  BACKGROUND
  The invasive assessment of left ventricular filling pressures is of importance in the evaluation and monitoring of critically ill patients. The left atrium is in very close proximity to the esophagus. We hypothesized that the temporal pressure decay characteristics of an esophageal fluid volume positioned at the level ofthe left atrium should depend on the atrial and left ventricular filling pressure.
  
  
  METHODS
  In five pigs an esophageal balloon was placed at the level ofthe left atrium. The balloon was then pressurized to 50 mmHg followed by an automated release that allowed us to directly record the pressure decay, while simultaneously recording left atrial pressures. An algorithm was developed to estimate atrial pressures. We also tested if invasive transesophageal atrial pressures can be recorded via an ultrasound guided left atrial puncture.
  
  
  RESULTS
  Noninvasive transesophageal assessments of left atrial pressures are feasible. The left atrial pressure directly affects the esophageal pressure decay and correlates with the transition point from an exponential pressure decay to a more linear decay (r = 0.949). This approach also allows for the assessment of atrial waveforms. We could also demonstrate that invasive transesophageal pressure measurements are feasible and safe.
  
  
  CONCLUSIONS
  The esophagus allows for reproducible less invasive assessments of left ventricular filling pressures and atrial pressure waveforms. This close spatial relationship provides an alternative access site for diagnostic and therapeutic cardiac procedures.
authors.affiliation: Department of Medicine, Division of Cardiology and Gastroenterology, University of Vermont College of Medicine, Burlington, Vermont, USA.
authors.forename: Markus
authors.initials: M
authors.lastname: Meyer
authors.affiliation: Department of Medicine, Division of Cardiology and Gastroenterology, University of Vermont College of Medicine, Burlington, Vermont, USA.
authors.forename: Stephen P
authors.initials: SP
authors.lastname: Bell
authors.affiliation: Department of Medicine, Division of Cardiology and Gastroenterology, University of Vermont College of Medicine, Burlington, Vermont, USA.
authors.forename: Neeraj
authors.initials: N
authors.lastname: Sardana
authors.affiliation: Department of Medicine, Division of Cardiology and Gastroenterology, University of Vermont College of Medicine, Burlington, Vermont, USA.
authors.forename: Richard
authors.initials: R
authors.lastname: Zubarik
authors.affiliation: Department of Medicine, Division of Cardiology and Gastroenterology, University of Vermont College of Medicine, Burlington, Vermont, USA.
authors.forename: Martin M
authors.initials: MM
authors.lastname: Lewinter
authors.affiliation: Department of Medicine, Division of Cardiology and Gastroenterology, University of Vermont College of Medicine, Burlington, Vermont, USA.
authors.forename: Harold L
authors.initials: HL
authors.lastname: Dauerman
keywords: Diastolic filling pressures; esophagus; left atrium
references.citation: Chest. 2007 Feb;131(2):539-48
references.pmid: 17296659
references.citation: Ann Thorac Surg. 2005 Oct;80(4):1231-9
references.pmid: 16181845
references.citation: Circulation. 1982 Feb;65(2):336-41
references.pmid: 7053892
references.citation: Endoscopy. 2007 May;39(5):385-9
references.pmid: 17516342
references.citation: Pacing Clin Electrophysiol. 1983 Jan;6(1 Pt 1):60-72
references.pmid: 6188126
references.citation: N Engl J Med. 1952 Nov 13;247(20):768-71
references.pmid: 13002611
references.citation: Br Heart J. 1956 Jul;18(3):327-40
references.pmid: 13342297
references.citation: Am J Cardiol. 1973 Jul;32(1):85-90
references.pmid: 4713115
references.citation: J Am Coll Cardiol. 2006 Dec 19;48(12):2546-52
references.pmid: 17174196
references.citation: Rev Esp Enferm Dig. 2009 Sep;101(9):601-9
references.pmid: 19803662