Mitral Regurgitation Jet Area Research Articles

The impact of mitral regurgitation on patients undergoing catheter ablation of atrial fibrillation

Mitral regurgitation (MR) causes left atrium (LA) enlargement and subsequent atrial fibrillation (AF). The presence of MR may increase recurrence rates after AF ablation. The purpose of this study was to determine the impact of MR on recurrence rates after catheter ablation of AF. We compared 95 patients with moderate or greater baseline MR (defined by MR jet area to LA area ratio ≥ 0.2) and AF undergoing ablation to 95 randomly selected patients without significant MR undergoing AF ablation. Electrocardiographic recurrence at 1-year follow-up was the primary outcome. Patients in the MR cohort had mean MR/LA ratio 0.37 vs. 0.09 in controls (P< 0.0001). Mitral regurgitation patients had larger LA dimension (4.5 vs. 4.1 cm, P< 0.0001) and more persistent AF (71 vs. 28%, P< 0.0001). Mitral regurgitation patients had higher recurrence rates than controls (61 vs. 46%, P= 0.04). The degree of MR was higher in patients with recurrence (MR/LA ratio 0.25 vs. 0.20, P= 0.03), as was LA dimension (4.5 vs. 4.1 cm, P< 0.0001). In multivariate analyses, only LA size was an independent predictor of recurrence (odds ratio 2.9 per centimetre increase in LA dimension, P= 0.005). Fifty-five percent of MR patients had normal leaflet motion, with MR likely due to atrial remodelling secondary to AF. Mitral regurgitation was associated with increased AF recurrence after AF ablation, but its impact was mediated by LA size. Left atrium size was the only independent predictor of AF recurrence. The high percentage of MR that was likely secondary to AF may have impacted our findings and deserves further study.

Atrial asynchrony and function before and after electrical cardioversion for persistent atrial fibrillation

The relation between left atrial (LA) electrical and mechanical activity is a challenging field of investigation. The availability of echocardiographic strain analysis techniques has enhanced our ability to non-invasively assess LA wall mechanical synchrony and performance. The aim of our study was to investigate how new strain analysis tools describe the improvement in LA mechanical function after sinus rhythm (SR) restoration as a result of electrical cardioversion (CV) and how such improvement mirrors endocrine profile changes. Seventy-three patients, with persistent atrial fibrillation (AF) who underwent successful electrical CV, were prospectively studied with transthoracic echocardiography 1 week before CV and 1 month after SR. Speckle-tracking 2D-strain evaluation and asynchrony quantification were performed according to the standard deviation of time-to-peak (TP-SD) of deformation of six segments automatically located along the perimeter of the LA cavity, as imaged in an apical four-chamber view. We also calculated classic echocardiograhic parameters such as mitral regurgitation (MR) jet area, LA volume, LV diastolic and systolic volumes, as well as E-wave velocity and deceleration time (DT) on transmitral pulsed wave Doppler. Specimens for plasmatic brain natriuretic peptide (BNP) were also obtained before and 1 month after CV. After 1 month of SR, we detected a significant reduction in TP-SD (from 17.5 +/- 7.4 to 15.2 +/- 7.5%, P = 0.022), this being the expression of improved LA asynchrony, together with a marked increase in LA deformation (peak strain from 11.4 +/- 5.2 to 17.2 +/- 7.5%, P < 0.001) and a reduction in LA volume (-4.5 +/- 36%, P = 0.012). BNP decreased by one-third (from 127 +/- 96 to 86 +/- 89 pg/mL, P = 0.01). We also noticed improved ventricular pump performance [LV ejection fraction (EF) from 53 +/- 10 to 57 +/- 8%, P = <0.001] due to a 20 +/- 42% (P < 0.001) increase in LV diastolic volume (without variations in LV systolic volume and mass), a better diastolic profile (DT 34 +/- 64%, P = 0.003), and a reduction in MR jet area (-1.0 +/- 2.0 cm(2), P < 0.001). These findings are compatible with reverse LA remodelling secondary to SR maintenance, with a favourable effect on LV function that appears modulated by the atrium itself. A significant correlation (r = 0.40, P < 0.001) was demonstrated between TP-SD and peak strain data pre-post CV. At multivariate analysis, a significant capacity for the TP-SD/peak strain ratio to predict AF recurrence at 1-year follow-up (P = 0.013) was shown. Our novel noninvasive approach appears to be able to describe the LA mechanical behaviour during AF and how this ameliorates after 1 month of SR, together with an improved endocrine profile. LA mechanical data pre-CV can predict AF recurrence 1-year post CV.

Cardiac resynchronization therapy is effective even in elderly patients with comorbidities

The purpose of this study was to compare the effects of cardiac resynchronization therapy (CRT) in elderly patients (> or =65 years) with younger patients and to assess the impact of comorbidities in CRT remodeling response. This is a prospective study of 87 consecutive patients scheduled for CRT who underwent clinical and echocardiographic evaluation before and 6 months after CRT. A reduction in left ventricular end-systolic volume (LVESV) > or =15% after CRT defined remodeling responders, and a reduction of at least one New York Heart Association class defined clinical responders. Multivariate analysis was used to identify independent predictors of non-response to CRT in terms of reverse remodeling. The mean age was 62 +/- 11 years, with 36 elderly patients (41%). The baseline QRS duration was 145 +/- 32 ms. After CRT, there were significant and similar improvements of left ventricular (LV) ejection fraction, LVESV, LV dP/dt, and mitral regurgitation jet area (JA) between elderly (> or =65 years) and younger (<65 years) patients. The number of clinical and remodeling responders was comparable, and we found no significant differences in unplanned cardiac hospitalizations at 6 months between groups. Independent predictors of lack of remodeling response to CRT were QRS duration <120 ms, LV diastolic diameter >74 mm, and JA >10 cm(2) before CRT, but not comorbidities. This work suggests that being elderly is not an impediment to CRT success even in the presence of comorbidities.

Identification of 'super-responders' to cardiac resynchronization therapy: the importance of symptom duration and left ventricular geometry

Some patients show such an important clinical improvement and reverse remodelling after cardiac resynchronization therapy (CRT) that anatomy and function approach normal. These patients have been called 'super-responders'. The aim of our study was to identify predictors of becoming a super-responder after CRT. Eighty-seven consecutive patients who underwent CRT were prospectively studied. Before CRT and 6 months after, clinical and echocardiographic evaluation was performed. Patients with a decrease in New York Heart Association functional class >or=1, a two-fold or more increase of left ventricular ejection fraction (LVEF) or a final LVEF >45%, and a decrease in LV end-systolic volume >15% were classified as super-responders. There were 12% super-responders. At baseline, there were no significant differences between super-responders and the other patients, except for the fact that super-responders had significantly smaller mitral regurgitation and LV end-diastolic diameter (LVEDD) and a shorter duration of heart failure symptoms. Mitral regurgitation jet area, LVEDD, and duration of heart failure symptoms were correlated with this super-response. Moreover, an evolution of symptoms for <12 months was an independent predictor of super-response to CRT. Patients in earlier phases of the cardiomyopathy, with a less altered ventricular geometry, seem to have a greater probability of becoming super-responders.

Mitral Valve Repair Using Polytetrafluoroethylene Neochordae: Short-Term Outcomes

In recent years, mitral valve repair using polytetrafluoroethylene (PTFE) neochordae has been shown to be an effective technique for correcting valve prolapse due to chordal rupture or elongation. In this study, we evaluated our experience using this technique in a group of 21 patients. The median (range) follow-up period was 9 (1-26) months. There was no in-hospital mortality. During follow-up, improvement in both clinical and echocardiographic parameters were observed: 95.2% of patients were in I-II NYHA class and the mitral regurgitation jet area was less than 4 cm(2) in 85.7% of patients. These findings are consistent with those previously reported in the literature. However, these results relate to our initial experience, and long-term follow-up is still required.

Mechanisms of Reduction of Mitral Regurgitation by Cardiac Resynchronization Therapy: by Analysis of Left Ventricular Morphology

Purpose: It's well known the mechanism of functional mitral regurgitation(MR) is geometric distortion of the mitral apparatus by left ventricular(LV) dilatation, which increases leaflet tethering and restricts closure. The purpose of this study is to assess the relationship between LV morphologic change and reduction of MR after cardiac resynchronization therapy(CRT). Methods: We studied 46 non-ischemic cardiomyopathy patients, and 29 normal controls. Echocardiography was used to assess the severity of MR, LV shape, mitral valve morphology, and displacement of papillary muscles(PM). Results: In patients, LV shape was more spherical (sphericity index: 1.55 ± 0.25 vs. 1.93 ± 0.25 p < 0.001), anterior PM shifted posteriorly (PM angle; the angle between anterior PM and posterior interventricular groove: 151.6 ± 19.4 vs. 176.7 ± 15.1° p < 0.001), and mitral leaflets were more tethered (tethering area: 1.66 ± 0.56 vs. 0.43 ± 0.06 cm2 p < 0.001) than that of normal controls. However at 6 months after CRT, sphericity index (1.51 ± 0.20 to 1.89 ± 0.40 p < 0.001) and PM angle (146.6 ± 16.5 to 167.7 ± 17.7° p < 0.001) increased significantly. Moreover tethering area (1.63 ± 0.72 to 1.03 ± 0.77 cm2 p < 0.001), and MR jet area (28.7 ± 16.1 to 16.1 ± 19.3% of LA area p < 0.01) were reduced in responder. Indeed, tethering area correlated with sphericity index (r=-0.39 p < 0.001), and PM angle (r=−0.29 p < 0.01). Conclusions: CRT reduced the subvalvar traction by changing the shape of LV and restored displaced anterior PM toward original position. These morphological change contributes to the reduction of functional MR in patients treated with CRT.

Impact of Changes in Myocardial Velocity Assessed by Tissue Doppler Imaging during Exercise on Dynamic Mitral Regurgitation in Patients with Nonischemic Cardiomyopathy

We evaluated the myocardial contractile reserve related to exercise-induced changes in functional mitral regurgitation (MR) by tissue Doppler imaging (TDI). Supine bicycle exercise was performed in 35 patients with nonischemic cardiomyopathy (age 51 +/- 12 years; EF < 40%) and resting, and peak exercise 2D echocardiographic parameters, and TDI data were obtained. V(avg) was defined as the average of peak systolic velocities of six basal LV segments by TDI. Myocardial contractile reserve, which was calculated by [peak exercise V(avg)- baseline V(avg)], was represented as DeltaV(avg). Dyssynchrony index was derived from the standard deviation of the time to the peak systolic velocity of 12 LV segments. During exercise (9.7 +/- 2.4 minutes), the mean V(avg) increased from 4.0 +/- 0.8 cm/s to 5.5 +/- 1.0 cm/s. The effective regurgitant orifice area (ERO) and the ratio of MR jet area to the left atrial area (JLA%) were 1.9 +/- 2.9 mm(2) and 12 +/- 12%, respectively. During exercise, ERO and JLA% significantly increased to 6.2 +/- 6.4 mm(2) and 21 +/- 13% (P < 0.05), respectively, with individually variable changes. Tenting area was found to be an independent factor that showed a relationship with the baseline severity of MR (r = 0.561, P < 0.001). Dyssynchrony index and DeltaV(avg) were found to correlate with both maximal MR severity at peak exercise and changes in MR during exercise. By multivariate analysis, DeltaV(avg) was found to be an independent determinant of exercise-induced changes in ERO (DeltaERO; r =-0.707, P< 0.001) and changes in JLA% (DeltaJLA%; r =-0.663, P< 0.001). In patients with nonischemic cardiomyopathy, impaired contractile reserve assessed by TDI velocity data may be an independent determinant affecting exercise-induced changes in dynamic MR.

Effectiveness of cardiac resynchronisation therapy in patients with echocardiographic evidence of mechanical dyssynchrony

Cardiac resynchronisation therapy has proven to be effective in refractory heart failure (HF) patients with QRS >120-130 ms. Therefore, the aim of our study was to verify the long-term effectiveness of cardiac resynchronisation therapy in HF patients with echocardiographic evidence of mechanical asynchrony regardless of QRS duration. One hundred and six patients with New York Heart Association class II-IV HF and echocardiographic documentation of interventricular and intraventricular asynchrony underwent biventricular stimulation. A clinical and functional evaluation was performed at baseline, 1, 3, 6 months, and every 6 months thereafter. After a median follow-up of 16 months, a significant improvement was noted in ejection fraction, left ventricular diameters, mitral regurgitation jet area, interventricular and intraventricular echocardiographic indexes of asynchrony, and the 6-min walking distance (P < 0.001 for all). Death rates for all causes and for cardiac causes were 18.2 (95% confidence interval 12.8-25.9) and 13.5 (95% confidence interval 9.0-20.3) per 100 person-years, respectively. Patients in New York Heart Association class IV had an almost three-fold increase in risk of dying as compared to class II-III (hazard ratio 2.97, 95% confidence interval 1.30-6.79). Interventricular and intraventricular asynchrony at echocardiography may be useful in identifying HF patients suitable for cardiac resynchronisation therapy, with results comparable to those obtained with QRS duration selection criteria.

Mechanisms and Clinical Implications of Asymptomatic Mitral Regurgitation in Patients With Left Ventricular Dysfunction

Functional mitral regurgitation (MR) is common in patients with chronic heart failure (CHF). During exercise, hemodynamic changes such as elevation of blood pressure and an increase in the left ventricular end-diastolic dimension may increase MR. Severity of CHF is reflected by exercise tolerance and, therefore, MR during exercise is supposed to indicate the severity of heart failure. The degree of MR increase and left ventricle (LV) shape was quantified during exercise in CHF patients and were compared with exercise tolerance. Twenty patients with CHF (mean age: 63 years) underwent dynamic cycle exercise at steady-state levels of 80% and 150% of the anaerobic threshold (AT). The MR jet area and left atrial (LA) area were measured during exercise and the ratio of MR/LA was calculated. The LV shape was assessed by calculating the ratio of the major to the minor axis. The MR/LA ratio increased during exercise (rest: 16.9+/-6.5%, 80% AT: 21.9+/-8.9%, 150% AT: 30.9+/-11.2%; p<0.01) and the LV shape became more spherical (rest: 1.34+/-0.10, 80% AT: 1.31+/-0.10, 150% AT: 1.23+/-0.11; p<0.05). There was a negative correlation between MR/LA ratio and the ratio of the major to the minor axis (-0.722, r<0.01). MR during exercise increases as the severity of CHF increases. Functional MR is correlated with the shape of the LV.

Abstract 2262: No Impact Of The Mitral Annuloplasty On Overall Survival In Patients With Ischemic Cardiomyopathy - Long-term Follow-up Study.

Good long-term results are reported after the mitral valve (MV) repair for ischemic regurgitation. The aim of the study was to identify predictors of the overall survival after routine MV repair in patients with ischemic cardiomyopathy. Methods. 164 patients, 60.9±8.66 years old, with chronic ischemic mitral regurgitation and left ventricle ejection fraction (EF) = 30.7±6.04 undergoing coronary bypass with or without MV repair were prospectively followed for 5.1±1.63 years. A Cox proportional hazards model evaluated overall survival as a function of baseline age, sex, EF, mitral regurgitation jet area, left atrial area, atrial fibrillation, NYHA class, prior anterior or inferior myocardial infarction, medical comorbidities, MV repair, left ventricular plasty, left main and 3 vessel disease, venous graft to left anterior descending artery, number of grafts and year of operation. Treatment selection bias was controlled by deriving a propensity score for mitral annuloplasty. Results. Predictors included in the Cox regression model of overall survival are presented in table . The ROC curve analysis revealed EF &lt;30.0, (sensitivity and specificity - 61.7% and 59.0%, respectively) and serum creatinine &gt;1.17, (45.6% and 77.2%) as a cut-off values in the prediction of overall survival. Conclusions. There is no impact of the mitral annuloplasty on overall survival in these patients. MV repair can be safely added to coronary bypass grafting in patients with ischemic cardiomyopathy. Multivariable Cox regression analysis results

Correlation of the myocardial performance index with plasma B-type natriuretic peptide levels in patients with mitral regurgitation

The Myocardial performance index (MPI) is an echocardiographic index of combined systolic and diastolic function, calculated as isovolumetric relaxation time plus isovolumetric contraction time divided by ejection time. The aim of this study was to define the correlation of the MPI with plasma B-type natriuretic peptide (BNP) levels and echocardiographic parameters in patients with chronic mitral regurgitation (MR). About 33 patients with at least moderate MR of organic etiology were enrolled to the study. All patients undergone complete 2D and Doppler echocardiography. Plasma BNP levels were studied. BNP levels in NYHA classes I-III were 9.3 +/- 2.2 pg/ml, 61.3 +/- 12.2 pg/ml, and 199.6 +/- 55.2 pg/ml, respectively (I vs. II P < 0.001, I vs. III P < 0.001 and II vs. III P = 0.004). Myocardial performance index were 0.42 +/- 0.02, 0.49 +/- 0.02, and 0.52 +/- 0.03 in MR patients with NYHA I-III, respectively. MPI was significantly higher in patients with NYHA class III compared to NYHA I (P = 0.001) and NYHA II (P = 0.005). There were no correlations between MPI and left atrial diameter, MR jet area, MR index and systolic pulmonary artery pressure whereas left ventricle (LV) end-systolic volume (r = 0.38), LV end-diastolic volume (LVDV) (r = 0.40), LV ejection fraction (r = -0.59), NYHA class (r = 0.51) and plasma BNP levels (r = 0.67) were strongly correlated. Only independent variable affecting MPI was plasma BNP level (odds ratio [CI]: 2.18[0.002-0.098], P = 0.041). MPI is a powerful index in assessing the severity of left ventricular function and symptom severity in patients with MR. Plasma BNP is an independent predictor of MPI where both parameters assess combined systolic and diastolic LV function, effectively.

Dynamic Change in Mitral Annular Area and Motion During Percutaneous Mitral Annuloplasty for Ischemic Mitral Regurgitation: Preliminary Animal Study With Real-time 3-Dimensional Echocardiography

We used a novel 3-dimensional (3D) echocardiographic technique to evaluate the impact of a coronary sinus-based percutaneous transvenous mitral annuloplasty (PTMA) on dynamic changes in mitral annular geometry and motion during the cardiac cycle in 8 sheep with ischemic mitral regurgitation. Using real-time 3D echocardiographic data before and after PTMA, 10 points along the saddle-shaped annulus were identified. For every 3D volume/frame during a cardiac cycle, we assessed mitral annular area and excursion defined as the traveling distance of the annular center. The PTMA device reduced both minimum and maximal mitral annular area (9.5 +/- 0.9-7.0 +/- 0.6 and 12.8 +/- 1.3-9.8 +/- 1.5 cm(2), P < .001 for both, respectively) with reduction of mitral regurgitation jet area (5.1 +/- 2.3-1.2 +/- 0.8 cm(2), P < .001), whereas it did not significantly impair mitral annular excursion amplitude (8.3 +/- 1.1-7.0 +/- 1.9 mm, P = .13). This 3D echocardiographic method noninvasively enabled dynamic study of mitral annular geometry and motion with quantitative analysis of the impact of PTMA.

Functional Mitral Regurgitation During Exercise in Patients With Heart Failure

Functional mitral regurgitation (MR) is common in patients with chronic heart failure (CHF) and left ventricular dysfunction. The severity of CHF is expressed in terms of exercise tolerance, so MR during exercise would affect the severity of heart failure. However, it is not well known how much MR increases during exercise, or if it is related with severity of heart failure. Seventeen subjects underwent dynamic cycle exercise at steady-state levels of 80% and 150% of anaerobic threshold (AT). During each exercise level, the MR jet and left atrial (LA) area were measured, and the degree of MR was expressed as the ratio (MR/LA). The MR/LA increased slightly at 80% AT (rest: 15.5+/-7.8%, 80% AT: 21.7+/-9.3%, p<0.05). It increased more at 150% AT (29.2+/-11.6%, p<0.01). The MR/LA at both 80% and 150% AT weakly correlated with peak oxygen consumption/heart rate (r=-0.509). They showed a weakly positive correlation with the ventilatoly equivalent/CO(2) production slope (r=0.340). MR during exercise increases as stroke volume worsens during exercise, so evaluation of MR during exercise is important in the management of patients with CHF.

Coapsys Mitral Annuloplasty for Chronic Functional Ischemic Mitral Regurgitation: 1-Year Results

Untreated functional ischemic mitral regurgitation (MR) leads to reduced survival in patients undergoing coronary artery bypass grafting (CABG). However, mitral repair or replacement increases mortality and morbidity over CABG alone. The Myocor Coapsys annuloplasty system potentially reduces these risks by facilitating MR reduction on a beating heart without atriotomy. We present data from the first 11 patients completing 1-year follow-up of a total of 34 implanted patients. Patients referred for CABG with preoperative grade 2 or greater ischemic functional MR were included in this study. Patients with structural valve defects or who demonstrated MR less than grade 2 after CABG, despite hemodynamic challenge, were intraoperatively excluded. Coapsys consists of two epicardial pads connected by a flexible chord implanted by passing the chord across the left ventricle with special instruments without cardiopulmonary bypass. The system was sized to reduce critical valve dimensions and MR. Serial clinical and echocardiographic data were collected out to 1 year. Mean age was 58.1 +/- 6.6 years and mean ejection fraction, 38.5% +/- 7.1%. From baseline to 1-year follow-up, effect on MR grade, MR jet area (cm2), and New York Heart Association class were, respectively, 2.9 +/- 0.5 to 1.1 +/- 0.8, 7.4 +/- 2.9 to 3.0 +/- 1.6, and 2.5 +/- 0.5 to 1.2 +/- 0.4 (all p < 0.05 versus baseline). During follow-up, there were no deaths, device failures, reemergence of grade 3 or 4 MR, heart failure readmission, or valve reoperations. The Coapsys annuloplasty system is effective in reducing functional ischemic MR and improving NYHA class. The initial data are encouraging and suggest that the device is safe and benefits are sustained at 1 year.

Quantification of Mitral Regurgitation by Live Three‐Dimensional Transthoracic Echocardiographic Measurements of Vena Contracta Area

We evaluated 44 consecutive patients who underwent standard two-dimensional (2D) and live three-dimensional (3D) transthoracic echocardiography (TTE), as well as left heart catheterization with left ventriculography. Mitral regurgitant vena contracta area (VCA) was obtained by 3D TTE by systematic and sequential cropping of the acquired 3D TTE data set. Assessment of mitral regurgitation (MR) by ventriculography was compared to measurements of VCA by 3D TTE and to 2D TTE measurements of MR jet area to left atrial area (RJA/LAA), RJA alone, vena contracta width (VCW), and calculated VCA. VCA from 3D TTE closely correlated with angiographic grading (rs=0.88) with very little overlap. VCA of <0.2 cm2 correlated with mild MR, 0.2-0.4 cm2 with moderate MR, and >0.4 cm2 with severe MR by angiography. Ventriculographic grading also correlated well with 2D TTE measurements of RJA/LAA (rs=0.79) and RJA alone (rs=0.76) but with more overlap. Assessment of VCW and calculated VCA by 2D TTE agreed least with ventriculography (rs=0.51 and rs=0.55, respectively). Live 3D TTE color Doppler measurements of VCA can be used for quantitative assessment of MR and is comparable to assessment by ventriculography.

Quantification of acute reduction in mitral regurgitation following cardiac resynchronization therapy

Background: Cardiac resynchronization therapy (CRT) is associated with delayed improvements in cardiac function in heart failure patients with left bundle branch block (LBBB) secondary to reverse remodeling. However, the mechanisms of immediate benefits from CRT pacing are not well understood. Our objective was to assess the acute effects of CRT pacing on mitral regurgitation (MR) using quantitative volumetric Doppler echocardiography. Methods: Twenty-four HF patients with LBBB, aged 66±10 yrs, with ejection fraction of 25±7% and QRS duration of 168±35 ms were studied by quantitative 2-D and Doppler echocardiography at baseline and the day after CRT biventricular pacing therapy. MR was quantified with the volumetric method and expressed as regurgitant volume and regurgitant fraction, in addition to and digital color regurgitation jet area. MR regurgitant volume was obtained by subtracting left ventricular outflow tract stroke volume from mitral inflow stroke volume, determined by their respective time velocity integrals multiplied by cross-sectional area. MR regurgitant fraction was obtained by dividing regurgitant volume by mitral inflow stroke volume. Results: Baseline group mean MR regurgitant volume was 35±24 ml, MR regurgitant fraction was 35±17% and MR jet area was 6.9±4.9 cm2. After only 23±10 hours of CRT, significant improvements in MR occurred with regurgitant volume decreasing to 20±19 ml∗ and MR regurgitant fraction decreasing to 21±16%∗, (∗p<0.01 vs. baseline) (figure). MR jet area also decreased to 5.0±5.1 cm2 (p<0.05 vs. baseline). Acute reductions in MR were accompanied by a significant improvement in cardiac index from 2.1±0.5 to 2.4±0.6∗ L/min/m2 (∗p<0.05 vs. baseline). Conclusion: CRT resulted in acute significant reductions in MR and increases in cardiac index. These data support MR reduction as an important acute beneficial effect of CRT in HF patients with LBBB.

Mechanism of higher incidence of ischemic mitral regurgitation in patients with inferior myocardial infarction: Quantitative analysis of left ventricular and mitral valve geometry in 103 patients with prior myocardial infarction

Objective: The mechanism of higher incidence of ischemic mitral regurgitation in patients with inferior compared with anterior myocardial infarction despite less global left ventricular remodeling and dysfunction is controversial. We hypothesized that inferior myocardial infarction causes left ventricular remodeling, which displaces posterior papillary muscle away from its normal position, leading to ischemic mitral regurgitation. Methods: In 103 patients with prior myocardial infarction (61 anterior and 42 inferior) and 20 normal control subjects, we evaluated the grade of ischemic mitral regurgitation on the basis of the percentage of Doppler jet area, left ventricular end-diastolic and end-systolic volumes, midsystolic mitral annular area, and midsystolic leaflet-tethering distance between papillary muscle tips and the contralateral anterior mitral annulus, which were determined by means of quantitative echocardiography. Results: Global left ventricular dilatation and dysfunction were significantly less pronounced in patients with inferior myocardial infarction (left ventricular end-systolic volume: 52 ± 18 vs 60 ± 24 mL, inferior vs anterior infarction, P<.05; left ventricular ejection fraction: 51% ± 9% vs 42% ± 7%, P <.0001). However, the percentage of mitral regurgitation jet area and the incidence of significant regurgitation (percentage of jet area of 10% or greater) was greater in inferior infarction (percentage of jet area: 10.1% ± 7.5% vs 4.4% ± 7.0%, P =.0002; incidence: 16/42 (38%) vs 6/61 (10%), P <.0001). The mitral annulus (area = 8.2 ± 1.2 cm2 in control subjects) was similarly dilated in both inferior and anterior myocardial infarction (9.7 ± 1.7 vs. 9.5 ± 2.3 cm2, no significant difference), and the anterior papillary muscle-tethering distance (33.8 ± 2.6 mm in control subjects) was also similarly and mildly increased in both groups (35.2 ± 2.4 vs 35.2 ± 2.8 mm, no significant difference). However, the posterior papillary muscle-tethering distance (33.3 ± 2.3 mm in control subjects) was significantly greater in inferior compared with anterior myocardial infarction (38.3 ± 4.1 vs 34.7 ± 2.9 mm, P =.0001). Multiple stepwise regression analysis identified the increase in posterior papillary muscle-tethering distance divided by body surface area as an independent contributing factor to the percentage of mitral regurgitation jet area (r2 = 0.70, P <.0001). Conclusions: It is suggested that the higher incidence and greater severity of ischemic mitral regurgitation in patients with inferior compared with anterior myocardial infarction can be related to more severe geometric changes in the mitral valve apparatus with greater displacement of posterior papillary muscle caused by localized inferior basal left ventricular remodeling, which results in therapeutic implications for potential benefit of procedures, such as infarct plication and leaflet or chordal elongation, to reduce leaflet tethering.J Thorac Cardiovasc Surg 2003;125:135-43

Mitral valve prolapse in the general population: the benign nature of echocardiographic features in the framingham heart study

The aim of this study was to examine the echocardiographic features and associations of mitral valve prolapse (MVP) diagnosed by current two-dimensional echocardiographic criteria in an unselected outpatient sample.Previous studies of patients with MVP have emphasized the frequent occurrence of echocardiographic abnormalities such as significant mitral regurgitation (MR) and left atrial (LA) enlargement that are associated with clinical complications. These studies, however, have been limited by the use of hospital-based or referral series.We quantitatively studied all 150 subjects with possible MVP by echocardiography and 150 age- and gender-matched subjects without MVP from the 3,491 subjects in the Framingham Heart Study. Based on leaflet morphology, subjects were classified as having classic (n = 46), nonclassic (n = 37), or no MVP.Leaflet length, MR degree, and LA and left ventricular size were significantly but mildly increased in MVP (p < 0.0001 to 0.004), with mean values typically within normal range. Average MR jet area was 15.1 ± 1.4% (mild) in classic MVP and 8.9 ± 1.5% (trace) in nonclassic MVP; MR was severe in only 3 of 46 (6.5%) subjects with classic MVP, and LA volume was increased in only 8.7% of those with classic MVP and 2.7% of those with nonclassic MVP.Although the echocardiographic characteristics of subjects with MVP in the Framingham Heart Study differ from those without MVP, they display a far more benign profile of associated valvular, atrial, and ventricular abnormalities than previously reported in hospital- or referral-based series. Therefore, these findings may influence the perception of and approach to the outpatient with MVP.

Mitral valve prolapse in the general population: the benign nature of echocardiographic features in the Framingham Heart Study

ObjectivesThe aim of this study was to examine the echocardiographic features and associations of mitral valve prolapse (MVP) diagnosed by current two-dimensional echocardiographic criteria in an unselected outpatient sample. BackgroundPrevious studies of patients with MVP have emphasized the frequent occurrence of echocardiographic abnormalities such as significant mitral regurgitation (MR) and left atrial (LA) enlargement that are associated with clinical complications. These studies, however, have been limited by the use of hospital-based or referral series. MethodsWe quantitatively studied all 150 subjects with possible MVP by echocardiography and 150 age- and gender-matched subjects without MVP from the 3,491 subjects in the Framingham Heart Study. Based on leaflet morphology, subjects were classified as having classic (n = 46), nonclassic (n = 37), or no MVP. ResultsLeaflet length, MR degree, and LA and left ventricular size were significantly but mildly increased in MVP (p < 0.0001 to 0.004), with mean values typically within normal range. Average MR jet area was 15.1 ± 1.4% (mild) in classic MVP and 8.9 ± 1.5% (trace) in nonclassic MVP; MR was severe in only 3 of 46 (6.5%) subjects with classic MVP, and LA volume was increased in only 8.7% of those with classic MVP and 2.7% of those with nonclassic MVP. ConclusionsAlthough the echocardiographic characteristics of subjects with MVP in the Framingham Heart Study differ from those without MVP, they display a far more benign profile of associated valvular, atrial, and ventricular abnormalities than previously reported in hospital- or referral-based series. Therefore, these findings may influence the perception of and approach to the outpatient with MVP.

Impact of atrial fibrillation on tricuspid and mitral annular dilatation and valvular regurgitation.

To investigate the effects of atrial fibrillation (AF) on the mitral and tricuspid valves, the corresponding annular dilatation and valvular regurgitation were compared with 2-dimensional and Doppler echocardiography in 31 consecutive patients with lone AF and 28 normal controls. Mid-systolic mitral and tricuspid annular areas were measured from 2 diameters in 2 orthogonal apical echocardiograms. Percent (%) mitral regurgitant (MR) or tricuspid regurgitant (TR) jet area to the left or right atrial area was evaluated and % MR or TR jet area >20% was considered moderate or significant. Both the mitral and tricuspid annular areas in patients with lone AF were significantly larger compared with the controls (mitral: 9.5 +/- 1.2 vs 6.6 +/- 0.9 cm2, lone AF vs control, p < 0.01) (tricuspid: 12.0 +/- 2.0 vs 7.5 +/- 0.9 cm2, p < 0.01). The % increase in the annular area relative to the mean normal value was significantly greater in the tricuspid valve (44 +/- 18 vs 60 +/- 28%, p < 0.01). Moderate or severe MR was not observed and the incidence of moderate or severe valve regurgitation (% jet area >20%) was significantly higher in the tricuspid valve (0/31 vs 11/31, MR vs TR, p < 0.01) in patients with lone AF. The % TR jet area showed significant correlation with tricuspid annular area (r2 = 0.65, p < 0.001). Lone AF is associated with annular dilatation of both mitral and tricuspid valves, but the annular dilatation and valvular regurgitation are significantly greater in the tricuspid valve.