Diagnostic value of mitral regurgitant jet volume in the assessment of mitral regurgitation severity by general imaging three-dimensional quantification.

Accurate quantification of mitral regurgitation (MR) severity is critical for appropriate clinical decision making regarding surgical intervention. General imaging three-dimensional quantification (GI3DQ) method allows for direct measurement of mitral regurgitant jet volume (MRJvol) with the help of three-dimensional (3D) color flow Doppler imaging. The aim of this study was to evaluate diagnostic value of MRJvol by GI3DQ for MR grading severity, using the guideline recommended integrated approach as a reference. The study included ninety-seven patients with varying degree of MR, and all MR cases were divided into central MR group (n = 44) and eccentric MR group (n = 53). The MRJvol was measured by GI3DQ. The severity of MR was graded on the basis of recommended integrated approach as mild, moderate, or severe. As assessed by receiver operating characteristic analysis, MRJvol by GI3DQ at a cutoff value of 43.4 ml yielded 76.9% of sensitivity and 86.9% of specificity to differentiate moderate from severe MR in all cases, a cutoff value of 47.5 ml yielded 98.9% of sensitivity and 94.4% of specificity to differentiate moderate from severe MR in central MR, and a cutoff value of 40.7 ml yielded 80.0% of sensitivity and 78.6% of specificity to differentiate moderate from severe MR in eccentric MR. MRJvol measured by GI3DQ could assess MR severity, especially in central MR group, which has higher sensitivity and specificity to differentiate moderate from severe MR.

The impact of different geometric assumption of mitral annulus on the assessment of mitral regurgitation volume by Doppler method.

BACKGROUND: Mitral regurgitation volume (MRvol) by quantitative pulsed Doppler (QPD) method previously recommended suffers from geometric assumption error because of circular geometric assumption of mitral annulus (MA). Therefore, the aim of this study was to evaluate the impact of different geometric assumption of MA on the assessment of MRvol by two-dimensional transthoracic echocardiographic QPD method. METHODS: This study included 88 patients with varying degrees of mitral regurgitation (MR). The MRvol was evaluated by QPD method using circular or ellipse geometric assumption of MA. MRvol derived from effective regurgitant orifice area by real time three-dimensional echocardiography (RT3DE) multiplied by MR velocity-time integral was used as reference method. RESULTS: Assumption of a circular geometry of MA, QPD-MAA4C and QPD-MAPLAX overestimated the MRvol by a mean difference of 10.4 ml (P < 0.0001) and 22.5 ml (P < 0.0001) compared with RT3DE. Assumption of an ellipse geometry of MA, there was no significant difference of MRvol (mean difference = 1.7 ml, P = 0.0844) between the QPD-MAA4C + A2C and the RT3DE. CONCLUSIONS: Assuming that the MA was circular geometry previously recommended, the MRvol by QPD-MAA4C was overestimated compared with the reference method. However, assuming that the MA was ellipse geometry, the MRvol by the QPD-MAA4C + A2C has no significant difference with the reference method.

Assessment of right atrium dysfunction in patients with obstructive sleep apnea syndrome using velocity vector imaging.

BACKGROUND AND OBJECTIVES: This study aimed to assess the changes of RA function in patients with obstructive sleep apnea syndrome (OSAS) using velocity vector imaging (VVI) and to evaluate the application of VVI technology. METHODS: According to the apnea-hypopnea index (AHI), 71 patients with OSAS were divided into three groups: mild, moderate, and severe. A total of 30 cases of healthy subjects were enrolled as the control group. Digital images of apex four-chamber views were acquired to measure the right atrium (RA) linear dimensions and volume parameters including RA longitudinal diameter (RAL), transverse diameter (RAT), RA maximum volume (Vmax), RA minimum volume (Vmin), right atrial volume before contraction (Vpre). Right atrial volume parameters were corrected by body surface area (VImax, VImin, VIpre). The total right atrial emptying fraction (RATEF), right atrial passive emptying fraction (RAPEF), right atrial active contraction emptying fraction (RAAEF) were calculated. The VVI data measuring right atrial global strain (RA-GLS), right atrial strain rate in ventricular systolic phase (RA-SRs), right atrial strain rate in ventricular early diastolic phase (RA-SRe), right atrial strain rate in ventricular late diastolic phase (RA-SRa). RESULTS: 1. RA linear dimensions and volume parameters in severe OSAS were higher than those of control group. RAPEF in severe group was lower than control group and mild OSAS group (t = 2.681, P = 0.021; t = 2.985, P = 0.011; respectively). RAAEF in OSAS moderate group was higher than that of control group (t = 3.006, P = 0.02), and without statistical difference (P > 0.05) in the severe OSAS group and the control group. 2. RA-GLS in moderate OSAS group was significantly lower than that of control group (t = 2.333, P = 0.040) and reduced more obvious in the severe OSAS group (vs control, t = 3.25, P = 0.008, vs mild; t = 3.011, P = 0.012; respectively). RA-SRe in moderate and severe OSAS groups were lower than control group (t = 2.466, P = 0.031; t = 3.547, P = 0.005; respectively). RA-SRs of OSAS in severe group was lower than that of control and mild groups (t = 3.665, P = 0.004; t = 3.204, P = 0.008; respectively). RA-SRa in severe OSAS group was lower than that of control group (t = 2.425, P = 0.034). 3. Multivariate regression analysis showed that RA-GLS and RA-SRe were independently correlated with AHI (t = - 2.738, P = 0.010; t = - 2.191, P = 0.036; respectively). CONCLUSION: RA function was impaired in patients with OSAS. On hemodynamics, the change of RA function performed increased of reserve function, reduced pipeline function and increased of contraction function. However, the strain and strain rate reduced in different degree. RA-GLS and RA-SRe decreased the earliest, which suggested that strain and strain rate were the parameters which can reflect myocardial function damage earliest. VVI can more earlier and accurately detect myocardial dysfunction of right atrium in patients with OSAS, which is expected to be a worthy technique for early clinical therapy in patients with OSAS.