title: Intracardiac echocardiography: in vitro and in vivo validation for right ventricular volume and function.
abstract: To determine the feasibility and accuracy of intracardiac ultrasonography (ICUS) for the measurement of right ventricular (RV) volumes and function, a 10 MHz ICUS catheter was used in an in vitro and in vivo model. In the in vitro study, 16 sheep hearts were imaged. Sequential cross-sectional images from RV apex to base were recorded during a calibrated pullback. Volumes were calculated by applying Simpson's algorithm. ICUS-obtained volumes correlated well with actual volumes (standard error of estimate [SEE] = 2.3 ml, r = 0.98). For the in vivo study, a beating-heart canine model was used (31 hemodynamic stages in six dogs). Actual volumes were measured by an intracavitary balloon connected to an external column. Sequential cross-sectional images were recorded during the ICUS catheter pullback from apex to base of the RV, and volumes calculated by Simpson's algorithm. Good correlations were observed between ICUS and actual values for diastolic (SEE = 4.1 ml, r = 0.97), systolic (SEE = 3.4 ml, r = 0.96), and ejection fraction (SEE = 3.1%, r = 0.87) values. This new technique can accurately quantitate RV volumes, can function both in vitro and in vivo, and has the potential for increasing applications to questions of clinical and research interest.
authors.affiliation: Cardiac Ultrasound Laboratory, Massachusetts General Hospital, Boston, USA.
authors.forename: J A
authors.initials: JA
authors.lastname: Vazquez de Prada
authors.forename: M H
authors.initials: MH
authors.lastname: Chen
authors.forename: J L
authors.initials: JL
authors.lastname: Guerrero
authors.forename: L R
authors.initials: LR
authors.lastname: Padial
authors.forename: L
authors.initials: L
authors.lastname: Jiang
authors.forename: E
authors.initials: E
authors.lastname: Schwammenthal
authors.forename: A
authors.initials: A
authors.lastname: Sagie
authors.forename: A E
authors.initials: AE
authors.lastname: Weyman
authors.forename: R A
authors.initials: RA
authors.lastname: Levine
authors.forename: C
authors.initials: C
authors.lastname: Chen
mesh_terms: D000465:Algorithms; D000818:Animals; D006328:Cardiac Catheterization; D002306:Cardiac Volume; D004285:Dogs; D004452:Echocardiography / Q000379:methods*; D005240:Feasibility Studies; D017380:Hypertrophy, Right Ventricular / Q000000981:diagnostic imaging*; D015203:Reproducibility of Results; D012756:Sheep; D013318:Stroke Volume; D013599:Systole; D018084:Ultrasonography, Interventional / Q000379:methods; D016278:Ventricular Function, Right