Angiocardiographic pressure volume loops in the analysis of right ventricular function after repair of tetralogy of Fallot.

OBJECTIVE

The objective of the study was to estimate the capacity of pressure volume (PV) loop analysis to assess right ventricular (RV) function after Fallot (TOF) repair.

PATIENTS: Fifty six patients were examined after TOF repair. PV loops were constructed from RV angiocardiography and simultaneous pressure measurement. Patients were divided in three groups according to RV size and pressure (Group I: normal RV size and pressure; group II: enlarged RV, near normal pressure; group III: normal RV size, elevated pressure).

MAIN OUTCOME MEASURES: Systolic stroke work corrected for body surface area (W/BSA) and for RV enddiastolic volume (W/EDV), peak RV filling (PFR) and emptying rates (PER) corrected for RV stroke volume, cycle efficiency (CE), RV ejection fraction (RVEF).

RESULTS

W/BSA was significantly higher in group II than in group I (0.19 +/- 0.05 vs. 0.11 +/- 0.04 J/m(2), p < 0.001) and was similar between groups II and III (0.19 +/- 0.05 vs. 0.17 +/- 0.05 J/m(2) ; NS). W/EDV was similar in groups I and II (12.4 +/- 5.4 vs. 12.4 +/- 2.9 mmHg; NS). CE was smallest in group II. The difference was significant between groups II and III (0.62 +/- 0.08 vs. 0.73 +/- 0.09; p < 0.05). RVEF was negatively correlated to RV end systolic volume (RVESV) in the patients of groups I and II (r = -0.32, p < 0.05). A similar correlation was found between PFR and RVESV (r = -0.28, p < 0.05).

CONCLUSIONS

Analysis of a single PV loop allows quantification of RV load after TOF repair. W/BSA is increased to the same extent under volume and pressure load. The lack of decrease in W/EDV in patients with enlarged RV indicates that RV is capable to perform adequate work in a wide range. RVESV is a useful measure for estimating RV function after TOF repair depicting parameters of systolic and diastolic RV function.