Pulmonary venous systolic flow fraction in patients with mitral regurgitation: transoesophageal echocardiographic findings in relation to haemodynamic and angiographic evaluation

Long-term follow-up of mitral valve regurgitation--importance of mitral valve pathology and left ventricular function on survival

BACKGROUND

Timing of surgery for mitral regurgitation (MR) is one of the more difficult decisions for the practicing cardiologist.

METHODS AND RESULTS

In order to determine useful clinical cut-offs, we investigated the influence of baseline echocardiographic predictors for survival in a long-time follow-up cohort. Data from 144 patients with MR were collected between 1989 and 1993. Five-year mortality for MR patients was 30% compared to 13% for age- and sex matched controls (p<0.001). Each mm increase in left ventricular end systolic diameter (LVESD increased mortality with 2.5% (p<0.05) and each percent decrease in ejection fraction (EF) increased mortality with 1.8% (p<0.05). These effects were not linear and this material suggests cut-off points for LVESD to be 40 mm and EF 50%. Degree of MR did not correlate with survival, but patients with severe MR were operated more often than those with moderate MR. Patients with functional MR had reduced survival compared to patients with structural MR (p<0.01).

CONCLUSIONS

MR is a disease with greatly increased mortality and these data suggest a more aggressive approach to surgery.

Left atrial filling volume can be used to reliably estimate the regurgitant volume in mitral regurgitation

OBJECTIVES

The objective was to analyze the accuracy and diagnostic value of the estimated regurgitant volume of mitral regurgitation using 1) left atrial volume variation during ventricular systole (left atrial filling volume) and 2) the percent of systolic pulmonary vein velocity integral compared with its total.

BACKGROUND

Left atrial filling volume (LAfill), which represents the atrial volume variation during ventricular systole, has been used for the assessment of mitral regurgitation severity. A good correlation with invasive semiquantitative evaluation was found, but with an unacceptable overlapping among grades. The reason could be the absence of information concerning the contribution of blood entering into the left atrium from the pulmonary veins.

METHODS

Doppler regurgitant volume (Dpl-RVol) (mitral stroke volume - aortic stroke volume) was measured in 30 patients with varying degrees and etiological causes of mitral regurgitation. In each patient atrial volumes were measured from the apical view, using the biplane area-length method. The systolic time-velocity integral of pulmonary vein flow was expressed as a percentage of the total (systolic-diastolic) time-velocity integral (PVs%). These parameters were used in this group of patients to obtain an equation whose reliability in estimating Dpl-RVol was tested in a second group of patients.

RESULTS

In the initial study group, with linear regression analysis the following parameters correlated with Dpl-RVol: end-systolic left atrial volume (R2=0.37, p=0.0004); LAfill (R2=0.45, p < 0.0001); PVs% (R2=0.56, p < 0.0001). In multiple regression analysis the combination of LAfill and the percent of the systolic pulmonary vein velocity integral (PVs%) provided a more accurate estimate of regurgitant volume (R2=0.88; SEE 10.6; p < 0.0001; Dpl-RV=6.18 + (1.01 x LAfill) - (0.783 x PVs%). The equation was subsequently tested in 54 additional patients with mitral regurgitation with a mean Dpl-RVol 27+/-37 ml. Estimated regurgitant volume and Dpl-RVol correlated well with each other (R2=0.90; SEE 12.1; p < 0.0001). In the test population, the equation was 100% sensitive and 98% specific in detecting a regurgitant volume higher than 55 ml.

CONCLUSIONS

Left atrial filling volume and pulmonary vein flow give a reliable estimate of regurgitant volume in mitral regurgitation.

Pulmonary venous blood flow pattern in patients with univentricular hearts following total cavo-pulmonary connection

The objective of the study was evaluation of the pulmonary venous blood flow (PVF) pattern and the influence of ventricular function and atrioventricular valve regurgitation on this flow in patients with univentricular hearts post total cavo-pulmonary connection (TCPC). Transthoracic or transoesophageal echocardiographic studies were performed in 24 children with normal hearts (group A) and in 24 patients with univentricular hearts (group B). Ventricular function and atrioventricular valve regurgitation was semiquantitatively assessed. Systolic/diastolic maximal velocities and velocity time integrals (VTI) were measured from PVF tracings. Ejection fraction was measured by radionuclide angiography in 11 patients. Twelve patients underwent heart catheterization and angiography. In group B the PVF showed a biphasic flow velocity curve. The systolic integrals were smaller and the diastolic integrals were larger than in group A (6.4 vs. 13.0 cm, P = 0.0001, and 13.9 vs. 10.0 cm, P = 0.005). The pulmonary venous systolic flow fraction in 13 patients with an open fenestration and/or atrioventricular valve regurgitation grade 2-3 was significantly lower than in those 11 patients without fenestration and none/small regurgitation (0.19 vs. 0.40, P = 0.05). In conclusion, the PVF pattern in children with univentricular hearts pallitated with TCPC is similar to the PVF pattern found in individuals with biventricular hearts showing a biphasic flow velocity curve despite the absence of pulsatile pulmonary artery flow. The PVF in patients with TCPC-palliated univentricular hearts is influenced by atrioventricular valve regurgitation and fenestration flow.

Evaluation of mitral regurgitation by pulmonary venous blood flow patterns. Relation to angiographic and haemodynamic parameters in subgroups of patients

OBJECTIVES

To study the relationship between pulmonary venous systolic flow fraction (PVSFfr) recorded using pulsed Doppler transesophageal echocardiography and angiographic grading and haemodynamic parameters in subgroups of patients with mitral regurgitation.

BACKGROUND

Reversed systolic pulmonary venous flow is a sensitive sign of severe mitral regurgitation. Scarse data are available regarding the effects of atrial fibrillation and coronary artery disease.

METHODS

PVSFfr was calculated as the systolic flow velocity integral divided by the total inflow integral. PVSFfr is negative when systolic flow is dominantly reversed. 111 patients were studied.

RESULTS

PVSFfr < 0 was 91% sensitive for angiographic severe mitral regurgitation (MR) (specificity 75%). In patients with sinus rhythm and without coronary artery disease the sensitivity was 100% and specificity was 86% (n = 25). PVSFfr correlated to angiographic grade (r = -0.63, P = 0.0001), mean PCW (r = -0.63, P = 0.0001), v-wave (r = -0.72, P = 0.0001), systolic blood pressure (r = 0.28, P = 0.003) and left atrial diameter (r = -0.42, P = 0.0001) (n = 111). Stepwise linear regression analysis revealed the v-wave, angiographic grading, left atrial diameter and systolic blood pressure to be independent predictors of PVSFfr. Subgroup analysis revealed a correlation (r = 0.85, n = 25) between angiographic grading and PVSFfr in patients with sinus rhythm without CAD and (r = 0.35, n = 23) in patients with CAD in atrial fibrillation.

CONCLUSIONS

PVSFfr is valuable in assessing mitral regurgitation. In the presence of atrial fibrillation and coronary artery disease the correlation with angiographic grading decreases indicating the dynamic nature of this valvular lesion.