title: Left ventricular pseudohypertrophy in cardiac tamponade: an echocardiographic study in a canine model.
abstract: OBJECTIVE
  This study was designed to establish whether left ventricular pseudohypertrophy in cardiac tamponade can be reproducibly induced in an experimental canine model and to investigate the mechanism of its production.
  
  
  BACKGROUND
  Past experimental and clinical studies have shown reduction of ventricular volumes resulting from cardiac tamponade. Left ventricular pseudohypertrophy, a transient thickening of myocardial walls, was recently described as a new echocardiographic sign of cardiac tamponade.
  
  
  METHODS
  Cardiac tamponade was induced in seven anesthetized open chest dogs with serial bolus injections of 50 ml each of 0.9% saline solution into the pericardial sac. Under hemodynamic monitoring, M-mode and two-dimensional echocardiographic measurements were performed from a right parasternal window at each stage of graded cardiac tamponade.
  
  
  RESULTS
  There was a progressive increase of interventricular septal and posterior wall diastolic thickness. Mean wall thickness (interventricular septal thickness + posterior wall thickness divided by 2) was 9.8 +/- 1.3 mm at baseline, 14.3 +/- 0.9 mm at peak tamponade and 9.0 +/- 1.5 mm after fluid withdrawal (p < 0.0001). Mean wall thickness correlated directly with the severity of cardiac tamponade, as estimated from the level of right arterial pressures (r = 0.75 and p < 0.0001), and with the decrease of left ventricular cavity volume (r = -0.67 and p < 0.0001). Left ventricular mass did not change significantly.
  
  
  CONCLUSIONS
  Left ventricular pseudohypertrophy is a constant manifestation of cardiac tamponade in a canine model. The degree of myocardial thickening correlates with the reduction of ventricular dimensions and with the severity of hemodynamic compromise, representing a constant facet of heart remodeling in cardiac tamponade.
authors.affiliation: Henry Neufeld Cardiac Research Institute, Tel-Aviv, Israel.
authors.forename: E
authors.initials: E
authors.lastname: Di Segni
authors.forename: M S
authors.initials: MS
authors.lastname: Feinberg
authors.forename: M
authors.initials: M
authors.lastname: Sheinowitz
authors.forename: M
authors.initials: M
authors.lastname: Motro
authors.forename: A
authors.initials: A
authors.lastname: Battler
authors.forename: E
authors.initials: E
authors.lastname: Kaplinsky
authors.forename: Z
authors.initials: Z
authors.lastname: Vered
mesh_terms: D000818:Animals; D001794:Blood Pressure; D002305:Cardiac Tamponade / Q000150:complications* / Q000000981:diagnostic imaging; D004195:Disease Models, Animal; D004285:Dogs; D004452:Echocardiography; D006339:Heart Rate; D006352:Heart Ventricles / Q000473:pathology; D017379:Hypertrophy, Left Ventricular / Q000000981:diagnostic imaging / Q000209:etiology* / Q000473:pathology; D008955:Models, Cardiovascular