Pulmonary venous flow dynamics before and after balloon mitral valvuloplasty as determined by transesophageal Doppler echocardiography.

The pattern of left atrial filling was studied in 14 patients with severe mitral stenosis in sinus rhythm before and immediately after successful balloon mitral valvuloplasty by transesophageal pulsed Doppler echocardiography of the left superior pulmonary vein. Mean mitral valve orifice area increased from 0.8 +/- 0.1 to 2.2 +/- 0.3 cm2 (p less than 0.0001), and left atrial mean pressure decreased from 30 +/- 5 to 12 +/- 4 mm Hg (p less than 0.0001) after the procedure. After balloon mitral valvuloplasty, significant increases in peak systolic pulmonary velocity (35 +/- 16 to 44 +/- 10 cm/s; p less than 0.01), systolic flow velocity time integral (3.3 +/- 1.5 to 5.9 +/- 2.0 cm; p less than 0.001) and the ratio of systolic/diastolic pulmonary venous flow velocity time integrals (0.8 +/- 0.4 to 1.4 +/- 0.5; p less than 0.001) were observed. An acute increase in mitral valve orifice area caused no significant changes in peak diastolic forward flow velocity (40 +/- 7 to 41 +/- 9 cm/s; p = not significant [NS]), diastolic forward flow velocity time integral (4.3 +/- 1.7 to 4.6 +/- 1.8 cm; p = NS) and atrial flow reversal velocity (30 +/- 3 to 35 +/- 3 cm/s; p = NS) compared with at baseline. The results suggest that in patients with severe mitral stenosis and sinus rhythm, left atrial filling is biphasic with a diastolic preponderance, and successful mitral valvuloplasty is associated with an immediate increase in pulmonary venous systolic forward flow.     

Progressive improvement in pulmonary vascular resistance after percutaneous mitral valvuloplasty

Percutaneous mitral valvuloplasty has been proposed as a nonsurgical technique for treating high-risk patients with mitral stenosis who are deferred from mitral valve replacement. The effect of this technique on patients with pulmonary hypertension, however, has not been fully evaluated. Accordingly, serial assessment of pulmonary vascular resistance was made in 14 patients with critical mitral stenosis and pulmonary hypertension (pulmonary vascular resistance greater than 250 dynes.sec/cm5 or mean pulmonary artery pressure greater than 40 mm Hg or both) who underwent percutaneous balloon dilatation of the mitral valve. Balloon valvuloplasty was performed with either one (n = 10) or two (n = 4) balloons through the transseptal approach, and it resulted in significant improvement in mean mitral gradient (from 18 +/- 4 to 9 +/- 4 mm Hg, p less than 0.001), systemic blood flow (from 3.7 +/- 1.2 to 5.0 +/- 2.2 l/min, p less than 0.001), and calculated mitral valve area (from 0.7 +/- 0.2 to 1.6 +/- 0.7 cm2, p less than 0.001). Immediately after balloon mitral valvuloplasty, pulmonary vascular resistance fell from 630 +/- 570 to 447 +/- 324 dynes.sec/cm5. Repeat catheterization 7 +/- 4 months after valvuloplasty showed further improvement of pulmonary hypertension in 12 of the 14 patients, with a mean pulmonary vascular resistance for the group as a whole of 280 +/- 183 dynes.sec/cm5, p less than 0.005. In two patients, mitral valve restenosis to a mitral valve area less than 1.0 cm2 was associated with a return of pulmonary hypertension to predilatation values.(ABSTRACT TRUNCATED AT 250 WORDS)     

Atrial septal defect after percutaneous mitral balloon valvuloplasty: immediate results and follow-up

Percutaneous mitral balloon valvuloplasty was performed in 150 patients. There were 124 women and 26 men (mean age 53 +/- 1 years). A left to right shunt through the created atrial communication was present in 28 patients (19%) after valvuloplasty. The pulmonary to systemic flow ratio was greater than or equal to 2:1 in 4 patients and less than 2:1 in 24. Univariate predictors of left to right shunting after valvuloplasty included older age (p less than 0.01), lower cardiac output before mitral valvuloplasty (p less than 0.01), higher New York Heart Association functional class before valvuloplasty (p less than 0.05), presence of mitral valve calcification under fluoroscopy (p less than 0.01) and higher echocardiographic score (p less than 0.05). Multiple stepwise logistic regression analysis identified the presence of mitral valve calcification (p less than 0.02) and lower cardiac output (p less than 0.02) as the independent predictors of a left to right shunt through the atrial communication after balloon valvuloplasty. Follow-up (10 +/- 1 months) of patients with an atrial septal defect after valvuloplasty showed that 1) 6 patients died (3 in the hospital and 3 at 2, 16 and 18 months, respectively, after valvuloplasty); 2) an atrial septal defect was demonstrated in 3 of 6 patients who underwent mitral valve replacement (6 +/- 0.8 months after valvuloplasty); and 3) 13 patients were in functional class I, 2 patients were in class II and 1 patient was in class III at 13 +/- 1 months after valvuloplasty.(ABSTRACT TRUNCATED AT 250 WORDS)     

Favorable effect of balloon mitral valvuloplasty on the incidence of atrial fibrillation in patients with severe mitral stenosis.

BACKGROUND: The long-term effect of balloon mitral valvuloplasty (BMV) on the incidence of atrial fibrillation (AF) in patients with severe mitral stenosis (MS) remains undetermined. AIMS: To assess the effect of successful BMV on the incidence of chronic AF in patients with severe MS, compare the results with historical controls, and identify factors associated with AF in such patients. METHODS: Retrospective analysis of 382 consecutive patients with severe MS and in sinus rhythm (SR) who underwent successful BMV (post procedure mitral valve area (MVA) > or =1.5 cm(2), mitral regurgitation (MR) < or =2/4) at our hospital and followed-up for 1-15.6 (mean 5.6 +/- 3.9) years with clinical and echocardiographic examination. RESULTS: Thirty-four (8.9%) patients developed AF at follow-up (group A) and 348 patients (group B) remained in SR. At baseline, and in comparison with group B, patients who developed AF (group A) were older, had higher mitral echo score but equal MVA and left atrial (LA) size. The postprocedure MVA was smaller in group A (1.7 +/- 0.3 cm(2)) than in group B (2.0 +/- 0.2 cm(2;) P = 0.002). At follow-up, and in comparison to group B, group A had smaller MVA (1.5 +/- 0.4 cm(2) vs 1.8 +/- 0.4 cm(2) P <0.0001), larger LA dimension (49.4 +/- 6.5 vs 42 +/- 6.5 mm; P <0.0001) and higher restenosis rate (35% vs 14%; P = 0.001). Multivariate logistic regression analysis identified age at follow-up (P < 0.0001), LA size at follow-up (P = 0.004), and MVA at follow-up (P = 0.006) as predictors of AF. CONCLUSIONS: This study demonstrated favorable effect of BMV on the incidence of AF (8.9%) in patients with severe MS in comparison with reported series (29%) of patients with severe MS with similar baseline characteristics who were not submitted to any intervention. The predictors of AF were age, larger LA, and smaller MVA, at follow-up.     

Responsiveness of plasma atrial natriuretic factor to short-term changes in left atrial hemodynamics after percutaneous balloon mitral valvuloplasty

To assess the effect of short-term alteration of left atrial pressure and volume on the circulating plasma level of atrial natriuretic factor, 11 patients with left atrial hypertension due to mitral stenosis were studied at the time of percutaneous balloon mitral valvuloplasty. Hemodynamic measurements and plasma atrial natriuretic factor levels were obtained before, immediately (5 to 10 min) after and 24 h after valvuloplasty, and echocardiographic left atrial size was determined before and 24 h after valvuloplasty. Immediately after valvuloplasty, left atrial pressure decreased from 28 +/- 2 to 10 +/- 1 mm Hg (p less than 0.0005), mitral pressure gradient decreased from 20 +/- 2 to 7 +/- 1 mm Hg (p less than 0.0005), mitral valve area increased from 0.8 +/- 0.1 to 1.9 +/- 0.2 cm2 (p less than 0.0005) and plasma atrial natriuretic factor level rose from 249 +/- 42 to 348 +/- 50 pg/ml (p less than 0.01). This short-term rise in atrial natriuretic factor level may reflect a transient increase in left atrial pressure associated with balloon occlusion of the mitral valve.(ABSTRACT TRUNCATED AT 250 WORDS)     

Percutaneous balloon mitral valvuloplasty in rheumatic mitral stenosis: an experience of 50 patients in India

We attempted percutaneous balloon mitral valvuloplasty in 50 patients (27 female and 23 male, age 10-38 years) with rheumatic mitral stenosis. The procedure could be completed in 40 patients. The failures were caused by problems related to transseptal puncture in eight cases and inability to cross the mitral valve in two cases. Immediately after valvuloplasty there was a remarkable reduction in the mean pulmonary artery pressure, left atrial mean pressure, mean diastolic gradient across the mitral valve, and the calculated pulmonary vascular resistance. The calculated mitral valve area increased and the cardiac index increased marginally. Inadequate results with a post valvuloplasty mitral valve area of 0.9 cm2 were seen in only one patient. Repeat hemodynamic evaluation in 25 patients within two weeks of valvuloplasty showed persistent benefit in all except one patient, who showed partial restenosis. Follow-up cardiac catheterization at 3-6 months in 13 patients showed evidence of restenosis (mitral valve area less than 1.0 cm2 and mean diastolic gradient of greater than 10 mmHg) in one patient, while all others maintained hemodynamic benefit. Repeat hemodynamic evaluation at 9-18 months after valvuloplasty in eight patients showed evidence of restenosis in an additional two cases. The patients in our series are young (28 patients less than 20 years), small body surface area (1.35-0.2 m2), and have high left atrial and pulmonary arterial pressures.     

Echocardiographic evaluation of mitral valve structure and function in patients followed for at least 6 months after percutaneous balloon mitral valvuloplasty

Although beneficial results have been reported immediately after percutaneous mitral balloon valvuloplasty, little information is available concerning the longer-term outcome of this procedure. The anatomic and functional results of percutaneous mitral valvuloplasty were assessed in 20 patients, in whom two-dimensional and Doppler echocardiographic examination could be obtained both immediately and 6 to 11 months (mean 7.5 +/- 2.0) after balloon dilation. Mean valve area measured by planimetry decreased slightly but significantly from 1.90 +/- 0.59 cm2 immediately after valvuloplasty to 1.62 +/- 0.55 cm2 (p less than 0.001) at follow-up. Individual changes in valve area were variable, and in four patients valve area decreased by greater than 25%. Echocardiographic scores of valvular morphology were obtained by assigning scores of 0 to 4 (with increasing abnormality) to each of four morphologic characteristics of the valve, namely, leaflet mobility, thickening, calcification and subvalvular thickening. This score was higher in the four patients with a decrease in valve area greater than 25% at follow-up than in the other patients (11 +/- 2 versus 7 +/- 2, p less than 0.002). Multiple regression analysis of several hemodynamic and echocardiographic factors identify first the echocardiographic score and second the valve area postvalvuloplasty as the only significant predictors of the percent decrease in valve area (r = 0.70, p less than 0.006). Mitral regurgitation graded by pulsed Doppler ultrasound decreased from 1.9 +/- 1.2 immediately after valvuloplasty to 1.0 +/- 0.9 (p less than 0.003) at follow-up, whereas there was no change in mean transmitral pressure gradient by Doppler echocardiography (5 +/- 2 versus 6 +/- 3 mm Hg, p = NS) and left atrial volume (74 +/- 34 versus 72 +/- 27 cm3, p = NS). Thus, 6 to 11 months after balloon mitral valvuloplasty, mean mitral valve area decreases slightly. Individual changes in valve area, however, are variable. Valvular morphology assessed by two-dimensional echocardiography may be useful for identifying those patients who have an increased likelihood of developing valvular restenosis.     

Hemodynamic effects and long-term outcome of percutaneous balloon valvuloplasty in patients with mitral stenosis and atrial fibrillation

BACKGROUND: The presence of atrial fibrillation (AF) has been identified as a predictor of a suboptimal result in some patients undergoing percutaneous balloon valvuloplasty in the treatment of symptomatic rheumatic mitral stenosis. HYPOTHESIS: Atrial fibrillation adversely affects the short- and long-term outcome of patients with mitral stenosis undergoing percutaneous balloon valvuloplasty. METHODS: A retrospective chart review of 104 consecutive patients with rheumatic mitral stenosis undergoing percutaneous balloon valvuloplasty was performed. A successful procedure was defined as a final mitral valve area > or = 1.5 cm2 and the absence of a complication. Endpoints included freedom from mitral valve replacement, death, and repeat balloon valvuloplasty at 5 years. RESULTS: A successful procedure was obtained in 89% of patients with sinus rhythm and in 78% of patients with AF (p = NS). Patients in sinus rhythm had a greater cardiac output resulting in a larger final valve area than patients in AF (1.8 vs. 1.6 cm2, p < 0.05). Freedom from valve replacement, death, and repeat balloon valvuloplasty at 5 years was 75% for patients in AF and 76% for patients in sinus rhythm (p = NS). Lower postprocedure mitral regurgitation grade and absence of prior commissurotomy were the only independent predictors of event-free survival. CONCLUSIONS: Patients with mitral stenosis and AF have lower cardiac outputs and gradients than patients with sinus rhythm, despite similar valve areas. The long-term outcome of balloon valvuloplasty is independent of the initial cardiac rhythm.     

Percutaneous transvenous mitral commissurotomy and radiofrequency catheter ablation in patients with mitral stenosis.

BACKGROUND: The purpose of this study was to evaluate the short- and long-term results of radiofrequency catheter ablation (RFCA) for the treatment of atrial fibrillation (AF) in patients with mitral stenosis (MS) following percutaneous transvenous mitral commissurotomy (PTMC). METHODS AND RESULTS: Four patients (2 males, age 59+/-6 years) underwent simultaneous PTMC and pulmonary vein (PV) ablation. All patient had AF and MS (2 had persistent AF >1 month, 2 had paroxysmal AF), and the mean duration of AF was 3.4+/-3.3 years. The mean left atrial dimension was 47+/-7 mm and the mean ejection fraction was 58+/-4%. After PTMC, RFCA was performed in all patients (3 underwent PV isolation and 1 had PV focal ablation). The mitral valve area increased from 1.11 +/-0.19 to 1.90+/-0.20 cm(2) (p < 0.01). The frequency of AF episodes was dramatically reduced in the 2 patients with paroxysmal AF, and the 1 with persistent AF maintained sinus rhythm, but 1 patient with persistent AF developed recurrent AF. No complications or cardiac events occurred in any of the patients. CONCLUSION: The combination of RFCA and PTMC was safe and feasible, and may be useful in patients with MS and AF.     

Percutaneous balloon mitral valvuloplasty using the Inoue balloon: analysis of echocardiographic and other variables related to immediate outcome

To determine whether the mitral valve morphology influences the results of percutaneous balloon mitral valvuloplasty for mitral stenosis, two-dimensional echocardiography was performed before valvuloplasty in 126 patients (mean age 25.5+/-9.4 years) and in 30 normal controls. The 2D echocardiographic features of mitral valve leaflets: thickness, length and motion; diastolic mitral valvular excursion; chordal length; mitral annular diameter; subvalvular distance ratio; distance between mid mitral annulus to left ventricular apex, base and tip of papillary muscle and effective balloon dilating area, effective balloon dilating area/body surface area and effective balloon dilating diameter/mitral annular diameter were then correlated to the immediate post-valvuloplasty mitral valve area. For the total patients population, post-valvuloplasty valve area increased from 0.67+/-0.17 to 2.1+/-0.86 cm2 (P<0.0001), mean transmitral diastolic gradient decreased from 24.5+/-9.0 to 6.0+/-3.0 mm Hg (P<0.0001), mean left atrial pressure decreased from 29.7+/-6.2 to 12.7+/-4.8 mm Hg (P<0.0001), mean pulmonary artery pressure decreased from 44.8+/-14.2 to 25.4+/-9.5 mm Hg (P<0.0001) and cardiac index increased from 2.7+/-0.38 to 3.1+/-0.55 l/min/m2 (P<0.0001). The patients were divided into three groups on the basis of post-valvuloplasty mitral valve area. Group I had valve area <1.5 cm2, group II had valve area from 1.5 to 1.9 cm2 and group III had valve area > or =2.0 cm2. On comparison, no statistically significant difference was found in any of the echocardiographic variables in the three groups. On univariate, multivariate, multiple regression and discriminate function analysis, none of the variables were found to have significant influence on immediate result of valvuloplasty. There was no significant difference in the incidence of mitral regurgitation in any of the three groups. We conclude that the extent of mitral valvular and subvalvular deformity do not have a significant effect on the immediate outcome of mitral valvuloplasty using the Inoue balloon and it can be successfully performed in patients with severe subvalvular fibrosis. Unique balloon geometry and stepwise balloon sizing may explain these acceptable immediate results in severely deformed valves.     

Mitral regurgitation after percutaneous balloon mitral valvuloplasty in adults: evaluation by pulsed Doppler echocardiography

Percutaneous balloon mitral valvuloplasty is a new technique used in the treatment of adult patients with mitral stenosis. To evaluate the occurrence and severity of mitral regurgitation after balloon valvuloplasty, 24 patients (20 women and 4 men, mean age 57 years) were studied using two-dimensional and Doppler echocardiography before and less than 24 h after this procedure. Mitral valve area increased after valvuloplasty in all patients, from 0.89 +/- 0.07 to 1.61 +/- 0.09 cm2 (p less than 0.001). Before valvuloplasty, 10 patients had no mitral regurgitation, 4 had 1+, 4 had 2+ and 6 had 3+ mitral regurgitation. After valvuloplasty, new mitral regurgitation occurred in six patients. Regurgitation grade did not change in 13 patients (54%), increased by one grade in 8 patients (33%) and by two grades in 3 patients (13%). Left atrial volume decreased in all except one patient from 100 +/- 12 to 83 +/- 12 cm3 (p less than 0.001). Neither age, sex, cardiac rhythm, initial mitral valve area, increase in mitral valve area, morphologic characteristics of the valvular and subvalvular apparatus, previous mitral commissurotomy nor effective balloon dilating area discriminated between those patients with and without an increase in mitral regurgitation after valvuloplasty. Thus, mitral balloon valvuloplasty is frequently associated with an increase in mitral regurgitation. However, in this series, no patient developed severe mitral regurgitation, and left atrial volume decreased in nearly all patients. An increase in mitral regurgitation could not be predicted from any features of the valve or subvalvular apparatus, clinical characteristics of the patients or technical aspects of the procedure.     

Comparison of early versus late experience with percutaneous mitral balloon valvuloplasty

The immediate outcome of the first 150 patients (Group 1) and the last 161 patients (Group 2) who underwent percutaneous mitral balloon valvuloplasty was compared. There was no difference between the two groups in age, gender, New York Heart Association functional class, presence of calcification, atrial fibrillation, degree of mitral regurgitation, mean pulmonary artery pressure, left atrial pressure, cardiac output, pulmonary vascular resistance, mitral valve gradient and mitral valve area. Fewer patients in Group 1 than Group 2 had an echocardiographic score less than or equal to 8 (62% versus 69%, respectively, p = 0.02). The atrial septum was dilated with an 8 mm balloon in 74% of patients in Group 1 and with a 5 mm balloon in all patients in Group 2. Ratio of effective balloon dilating area to body surface area was larger in Group 1 than in Group 2 (4.05 +/- 0.07 versus 3.7 +/- 0.03 cm2/m2, p = 0.0001). A good result (mitral valve area greater than or equal to 1.5 cm2) was obtained in 77% and 75% in Groups 1 and 2, respectively (p = NS). After percutaneous mitral valvuloplasty, a greater than or equal to 2 grade increase in mitral regurgitation was noted in 12% of Group 1 and 6% of Group 2 (p = 0.02) and a left to right shunt was detected in 22% of Group 1 and 11% of Group 2 (p = 0.0001). There were three procedure-related deaths in Group 1, but none in Group 2.(ABSTRACT TRUNCATED AT 250 WORDS)     

Mitral balloon valvuloplasty for mitral restenosis after surgical commissurotomy

Mitral balloon valvuloplasty was performed in 14 patients with recurrent mitral stenosis 16.9 +/- 1.8 years (range 6 to 30) after surgical commissurotomy. There were 13 women and 1 man with a mean age of 55 +/- 4 years (range 23 to 73). Mitral balloon valvuloplasty resulted in an increase in mitral valve area from 0.8 +/- 0.1 to 1.7 +/- 0.2 cm2 (p = 0.001), a decrease in mean mitral diastolic pressure gradient from 15 +/- 2 to 7 +/- 1 mm Hg (p = 0.001) and an increase in cardiac output from 3.4 +/- 0.3 to 3.9 +/- 0.3 liters/min (p = 0.03). No deaths, strokes, vascular complications or conduction abnormalities were observed. Mitral regurgitation developed or increased in severity in seven patients (50%). There was no evidence of significant left to right shunt through the atrial septal puncture site after mitral balloon valvuloplasty. A good result (defined as a mitral valve area greater than 1.0 cm2, an increase in mitral valve area greater than 25% and a mean gradient less than 10 mm Hg) was achieved in 9 (64%) of the 14 patients. A subgroup of four patients who had a superior result (increase in mitral valve area of 1.7 +/- 0.2 versus 0.5 +/- 0.1 cm2 in the other 10 patients, p = 0.004) was identified. These patients had less echocardiographic evidence of rheumatic mitral valve damage and were the only patients who had sinus rhythm. They were also younger, less debilitated and had a lower grade of fluoroscopic valve calcification compared with the other patients. Thus, mitral balloon valvuloplasty is a safe and effective procedure for patients with recurrent mitral stenosis after surgical commissurotomy.(ABSTRACT TRUNCATED AT 250 WORDS)     

Serial assessment of mitral regurgitation by pulsed Doppler echocardiography in patients undergoing balloon aortic valvuloplasty

Mitral regurgitation was serially assessed by pulsed Doppler echocardiography in 144 patients undergoing balloon aortic valvuloplasty for symptomatic aortic stenosis. Regurgitant scores of 0, 1, 2 and 3 were assigned to pulsed Doppler patterns corresponding to no, mild, moderate and severe mitral regurgitation, respectively. Before balloon aortic valvuloplasty, mitral regurgitant score correlated significantly (p less than 0.005) but weakly with aortic valve area (r = -0.24), left ventricular ejection fraction (r = -0.34) and left ventricular systolic pressure (r = 0.23). There was no significant correlation between mitral regurgitation and either mean catheterization or mean Doppler aortic valve gradient. Balloon aortic valvuloplasty produced significant decreases in both catheterization and Doppler mean transvalvular aortic valve gradients (56 +/- 19 to 31 +/- 12 and 60 +/- 19 to 48 +/- 16 mm Hg, respectively; both p less than 0.0001) and a significant increase (p less than 0.0001) in aortic valve area assessed by catheterization (0.6 +/- 0.2 to 0.9 +/- 0.3 cm2). Left ventricular ejection fraction did not change, but cardiac output increased (p less than 0.001) and pulmonary capillary wedge pressure decreased (p less than 0.0001). Pulsed Doppler findings of mitral regurgitation were present in 102 of the 144 patients. Eighty-eight patients had a score compatible with mild or more severe degrees of mitral regurgitation, and 49 had a score indicative of moderate or severe valvular insufficiency. In the entire group of 144 patients, mitral regurgitant score decreased significantly from 1.1 +/- 1.0 to 1.0 +/- 1.0 (p less than 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)     

Transesophageal echocardiography to detect atrial clots in candidates for percutaneous transseptal mitral balloon valvuloplasty

Left atrial thrombi are common in patients with mitral stenosis. When percutaneous balloon mitral valvuloplasty is performed on such patients, there is a potential risk of thrombus dislodgment and embolization. In this study conventional transthoracic echocardiography and transesophageal echocardiography were performed for percutaneous balloon mitral valvuloplasty on 19 consecutive candidates (6 men, 13 women, 23 to 81 years old). In five patients (26%), transesophageal echocardiography revealed a left atrial thrombus; in only one of these was there a suspicion of left atrial thrombus on transthoracic echocardiography. Balloon mitral valvuloplasty was canceled in four of the five patients. Three underwent mitral valve surgery that confirmed the echocardiographic findings. Transesophageal echocardiography is better than conventional transthoracic echocardiography in detecting left atrial clots in candidates for balloon mitral valvuloplasty. Because of the potential risk of embolization, transesophageal echocardiography is recommended in all candidates for balloon mitral valvuloplasty.     

One-year outcome of cardioversion of atrial fibrillation in patients with mitral stenosis after percutaneous balloon mitral valvuloplasty

Our objectives were to study the success rate of electrical cardioversion after percutaneous balloon mitral valvuloplasty (PBMV) in patients with symptomatic moderate-to-severe mitral stenosis and atrial fibrillation (AF) and the maintenance rate of sinus rhythm for < or =1 year. We studied patients with mitral stenosis and AF who were scheduled for PBMV. Electrical cardioversion was performed 1 month after PBMV. Amiodarone 200 mg/day was started the day after PBMV. The primary outcomes studied were the rate of successful cardioversion and the maintenance rate of sinus rhythm at 12 months. Of 272 patients scheduled for PBMV, 70 were enrolled. The average age was 45 +/- 10 years. The average mitral valve area was 0.82 +/- 0.22 cm(2). Cardioversion was successful in 50 patients (71%). Logistic regression analysis revealed that left atrial size and associated aortic valvular disease were predictors of successful cardioversion. Of the 50 patients with successful cardioversion, AF recurred in 24 (48%). An increased left atrial diameter was the only factor associated with AF recurrence at 12 months. In conclusion, good candidates for cardioversion after PBMV were those with a left atrial diameter of <60 mm and no associated aortic valvular disease -- approximately 43% of patients with AF scheduled for PBMV. In this group, about 2/3 were in sinus rhythm at 12 months after cardioversion.     

In vitro analysis of mechanisms of balloon valvuloplasty of stenotic mitral valves

Preliminary reports indicate that percutaneous balloon valvuloplasty is efficacious for treatment of mitral stenosis. The present study was designed to evaluate whether anatomic features of stenotic mitral valves in older adults affect the efficacy of balloon valvuloplasty and to determine the mechanism by which increased orifice area is accomplished. Fifteen mitral valves excised intact at the time of mitral valve replacement from patients with no more than 2+/4+ mitral a regurgitation were selected for study. Balloon valvuloplasty was performed using a sequence of dilation catheters with balloons 18 to 25 mm in inflated diameter. Mitral valve area, measured with a conical valve sizer, increased from 0.71 +/- 0.06 cm2 (mean +/- standard error of the mean) to 1.77 +/- 0.19 cm2 (p less than 0.0001) after valvuloplasty, resulting in an increase in calculated orifice area of 185 +/- 27% (range 34 to 407%). The increase in calculated orifice area correlated inversely with orifice area before valvuloplasty (r = -0.57; p = 0.026), but was unrelated to extent of calcific deposits on the prevalvuloplasty x-ray of the excised mitral valve. Gross examination together with x-ray analysis after valvuloplasty revealed that the mechanism of balloon valvuloplasty in each case involved commissural splitting, including splits through heavily calcified commissures, without grossly apparent detachment of tissue fragments. These findings suggest that balloon valvuloplasty augments the functional mitral valve orifice area in a manner analogous to standard surgical commissurotomy, and balloon valvuloplasty is likely to be efficacious for a wide spectrum of adult mitral valvular stenosis, including severe stenosis with extensive calcific deposits.     

Interpretation of cardiac pathophysiology from pressure waveform analysis: mitral valve gradients: Part II.

Balloon mitral commissurotomy in many patients will be as satisfactory as closed surgical commissurotomy. Data from combined hemodynamic and echocardiographic techniques elegantly elucidate the mechanisms of mitral valve flow and pathophysiology of disturbed pressure relationships between the left atrial and left ventricular chambers, both before and after balloon valvuloplasty. The pulmonary capillary wedge pressure may not be satisfactory to assess the success of gradient reduction after mitral valvuloplasty.     

Determinants of left atrial pressure in rheumatic mitral stenosis: role of left atrial compliance and "atrial stiffness"

BACKGROUND: A wide range of left atrial pressures exist in rheumatic mitral stenosis despite similar mitral valve area. Left atrial compliance may be an important determinant of left atrial pressure in mitral stenosis. Data regarding left atrial compliance in rheumatic mitral stenosis and changes following balloon mitral valvotomy are scarce. METHODS AND RESULTS: Left atrial compliance and predictors of left atrial pressure were analyzed in 85 patients with mitral stenosis undergoing balloon mitral valvotomy. The stroke volume was divided by systolic rise in left atrial pressure to calculate the left atrial compliance. Systolic rise in left atrial pressure was computed as difference between amplitudes of left atrial "v" wave and "x" descent. The mean left atrial compliance prior to balloon mitral valvotomy was 2.62+/-1.20 cm3/mmHg. Following successful balloon mitral valvotomy there was a significant fall in pulmonary artery pressure, mean left atrial pressure, transmitral gradient, and significant increase in cardiac output, stroke volume and mitral valve area. There was a marked increase in left atrial compliance from 2.62+/-1.20 to 6.1+/-3.16 cm3/mmHg. On univariate analysis pulmonary artery systolic pressure, pulmonary artery diastolic pressure, pulmonary artery mean pressure, mean transmitral gradient, mitral valve area and left atrial compliance were the only correlates of left atrial pressures, while no correlation was noted with age, gender, left atrial size, cardiac output and stroke volume. Those with higher pulmonary artery pressure, higher transmitral gradient, lower mitral valve area and lower left atrial compliance had higher left atrial mean pressure, and the strongest negative correlation was noted with left atrial compliance. On multivariate analysis the strongest predictors of left atrial mean pressure were transmitral gradient and left atrial compliance. CONCLUSIONS: Patients with rheumatic mitral stenosis have markedly depressed left atrial compliance and hence have "stiff" left atria. Left atrial compliance is an important determinant of left atrial pressure, and improves immediately after successful balloon mitral valvotomy, irrespective of pre-balloon mitral valvotomy left atrial pressures.     

Inoue balloon mitral valvuloplasty: long-term clinical and echocardiographic follow-up of a predominantly unfavourable population.

AIMS: To assess long-term outcome in a typical Western population of predominantly unfavourable patients undergoing Inoue balloon mitral valvuloplasty. Outcome amongst patients has only been undertaken in the medium term. Long-term echocardiographic data in particular are scarce. METHODS: Inoue mitral valvuloplasty was attempted in 106 patients. There were six technical failures; the procedure was therefore completed in 100 patients, who underwent annual clinical and echocardiographic follow-up. RESULTS: Patients were aged 63.5+/-10. 3 years. 82% were female. Unfavourable characteristics included age >65 (52%), NYHA class III or IV (87%), >/=1 significant co-morbidity (63%), atrial fibrillation (82%), previous surgical commissurotomy (25%) and echocardiographic score >8 (59%, mean 8.9+/-2.1). Mitral valve area increased from 0.98+/-0.23 to 1.54+/-0.31 cm(2). There were three major complications. Post-procedure, symptoms improved in 88% of patients. Haemodynamic success (mitral valve area increase >50%, final mitral valve area >1.5 cm(2), mitral regurgitation 50% gain in mitral valve area, mitral valve area <1.5cm (2)) was 98%, 92% and 75% at 1, 3 and 6 years. Pre-procedural predictors of event-free survival were male sex, absence of co-morbidities, lower echocardiographic score and smaller left atrial diameter. CONCLUSIONS: In a Western population with predominantly unfavourable characteristics for mitral valvuloplasty, long-term outcome post-procedure is reasonable. A moderate increase in mitral valve area can be achieved at low procedural risk, and the subsequent rate of restenosis is low. Nonetheless, 6 years after the procedure, half of the patients will have required further intervention or died. For fitter patients willing to accept significant operative risk, mitral valve replacement remains a valuable alternative.