Effect of left ventricular outflow on flow convergence region on the left septal surface in ventricular septal defect

Abstract

The corrected shunt flow rate (F_c) and corrected defect orifice area (A_c) were calculated by modified equation F = 2πR² × (NL-V_lvot × Sinθ) in 23 patients with single membranous ventricular septal defect, in order to correct the effect of left ventricular outflow on flow convergence region on the left septal surface. The results indicated that F_c was closely correlated with Q_p — Q₅ and Q_p/Q_s measured by pulsed wave Doppler (r = 0. 95 andr = 0. 81 respectively,P <0. 001). And the correlation between A_c and the diameter of defect (D_d) measured directly in two-dimensional views was better than that between uncorrected defect orifice area (A) and the D_d(r = 0. 98 and 0. 69, respectively,P <0. 001). The shunt flow rate calculated by ideal equation F = 2πR² × NL overestimated the actu al shunt flow rate in ventricular septal defect, especially in membranous type. Our study concluded that F_c can be used for a more accurate evaluation of the shunt seventy of ventricular septal defect.

Keywords

flow convergence / left ventricular outflow / ventricular septal defect

References

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