Mohan Jc

Percutaneous transatrial mitral commissurotomy: Immediate and intermediate results

OBJECTIVES The purpose of this study was to evaluate the immediate and follow-up results of percutaneous transatrial mitral commissurotomy in 600 patients with rheumatic mitral stenosis. BACKGROUND Percutaneous transatrial mitral commissurotomy has emerged as an effective nonsurgical technique for patients with symptomatic mitral stenosis. Several studies have shown that the immediate results are comparable to closed and open mitral valvotomy. METHODS Percutaneous transatrial mitral commissurotomy was performed in 600 patients with rheumatic mitral stenosis by the double-balloon (290 patients [48.3%]) and flow-guided Inoue balloon (310 patients [51.7%]) techniques. There were 154 male (25.6%) and 446 female (77.4%) patients with a mean [+/- SD] age of 27 +/- 8 years (range 8 to 60). Atrial fibrillation was present in 26 patients (4.3%), mitral regurgitation < or = grade 2 in 62 (10.3%) and densely calcific valve in 12 (2%). All patients had clinical and echocardiographic (two-dimensional, continuous wave Doppler, color flow imaging) follow-up at 3-month intervals. RESULTS Percutaneous transatrial mitral commissurotomy was successful in 589 patients (98.1%), and optimal commissurotomy was achieved in 562 (93.6%), with an increase in mitral valve area from (mean +/- SD) 0.75 +/- 0.18 to 2.2 +/- 0.38 cm2 (p < 0.001) and a decrease in transmitral end-diastolic gradient from 27.3 +/- 6.1 to 3.8 +/- 4.2 mm Hg (p < 0.001). Mitral regurgitation developed or increased in 208 patients (34.6%). Six patients (1%) with mitral regurgitation required mitral valve replacement. Cardiac tamponade occurred in 8 patients (1.3%). Six patients (1%) died. Restenosis developed in 10 patients (1.7%) during a mean follow-up period of 37 +/- 8 months (range 6 to 66). CONCLUSIONS Percutaneous transatrial mitral commissurotomy is an effective, safe procedure with gratifying intermediate results. It should be considered the treatment of choice for rheumatic mitral stenosis.

Left ventricular intrinsic contractility in pure rheumatic mitral stenosis

Abstract The status of left ventricular (LV) intrinsic contractile function in isolated rheumatic mitral stenosis (MS) is an unsettled issue. Although the overall LV ejection performance is reduced in a number of patients with MS, 1–3 it is a product of interaction between intrinsic contractility, preload and afterload. Although intrinsic LV contractility in MS has been found to be normal in 2 studies, 3,4 other investigators, using methods still to be validated, found it to be decreased. 5,6 Recently, reliable load-independent indexes of intrinsic contractility have been validated and applied in clinical studies. These are end-systolic pressure or end-systolic meridian wall stress to end-systolic volume or dimension ratio 7 and fractional fiber shortening to end-systolic stress relations. 8 We assessed LV intrinsic myocardial contractile function as measured by the aforementioned methods in patients with isolated rheumatic MS.

Percutaneous transvenous mitral commissurotomy: Immediate and long-term follow-up results

Percutaneous transvenous mitral commissurotomy has emerged as an effective nonsurgical technique for the treatment of patients with symptomatic mitral stenosis. This report highlights the immediate and long‐term follow‐up results of this procedure in an unselected cohort of patients with rheumatic mitral stenosis from a single center. It was performed in a total of 4,850 patients using double balloon in 320 (6.6%), flow‐guided Inoue balloon technique in 4,374 (90.2%), and metallic valvulotome in 156 (3.2%) patients. Their age range was 6.5–72 years (mean, 27.2 ± 11.2 years) and 1,552 (32%) patients were under 20 years of age. Atrial fibrillation was present in 702 (14.5%) patients. No patient was rejected on the basis of echocardiographic score using the Wilkins criteria. Echocardiographic score of ≥ 8 was present in 1,632 (33.6%) patients, of which 103 (2.1%) had densely calcified (Wilkins score 4+) valve. A detailed clinical and echocardiographic (two‐dimensional, continuous‐wave Doppler and color‐flow imaging) assessment was done at every 3 months for the first year and at 6‐month interval thereafter. The procedure was technically successful in 4,838 (99.8%) patients but optimal result was achieved in 4,408 (90.9%) patients with an increase in mitral valve area (MVA) from 0.7 ± 0.2 to 1.9 ± 0.3 cm2 (P < 0.001) and a reduction in mean transmitral gradient from 29.5 ± 7.0 to 5.9 ± 2.1 mm Hg (P < 0.001). The mean left atrial pressure decreased from 32.1 ± 9.8 to 13.1 ± 6.2 mm Hg (P < 0.001). Although there was no statistically significant difference in the MVA achieved between de novo and restenosed valves (1.9 ± 0.3 and 1.8 ± 0.2 cm2, respectively; P > 0.05), or between noncalcific and calcific valves (2.0 ± 0.3 and 1.8 ± 0.2 cm2, respectively; P > 0.05), on the whole MVA obtained after percutaneous transvenous mitral commissurotomy was less in restenosed and calcific valves. Ten (0.20%) patients had cardiac tamponade during the procedure. Mitral regurgitation appeared or worsened in 2,038 (42%) patients, of which 68 (1.4%) developed severe mitral regurgitation. Urgent mitral valve replacement was carried out in 52 (1.1%) of these patients. Data of 3,500 patients followed over a period of 94 ± 41 months (range, 12–166 months) revealed MVA of 1.7 ± 0.3 cm2. Elective mitral valve replacement was done in 34 (0.97%) patients. Mitral restenosis was seen in 168 (4.8%) patients, of which 133 (3.8%) were having recurrence of class III or more symptoms. Thus, percutaneous transvenous mitral commissurotomy is an effective and safe procedure with gratifying results in high percentage of patients. The benefits are sustained in a majority of these patients on long‐term follow‐up. It should be considered as the treatment of choice in patients with rheumatic mitral stenosis of all age groups. Cathet Cardiovasc Intervent 2002;55:450–456.

Is the mitral valve area flow-dependent in mitral stenosis? A Dobutamine stress echocardiographic study

OBJECTIVES The purpose of this study was to compare the effect of changes in flow rate on the mitral valve area (MVA) derived from two-dimensional echocardiographic planimetry and Doppler pressure half-time (PHT) methods in patients with mitral stenosis (MS). BACKGROUND Dobutamine stress echocardiography has been proposed as a means of assessing the severity of MS. However, data regarding the effect of an increase in flow rate on MVA are limited. If MVA is indeed flow-dependent, this has important implications for the assessment of the severity of MS, particularly in the setting of reduced cardiac output (CO). METHODS Dobutamine echocardiography was performed in 57 patients with isolated MS who were in sinus rhythm. The MVA was determined by planimetry and Doppler PHT methods. RESULTS Cardiac output increased by > or =50% in 27 patients (group I) and by <50% in 30 patients (group II). In group I, the MVA by planimetry increased by only 10.6 +/- 2% and the MVA by PHT increased by 21.9 +/- 4.8%. These changes were similar to those observed in group II (10.7 +/- 3% and 14.8 +/- 4%, respectively; p = NS), despite a much smaller increase in CO. A clinically important change (from the severe to mild category) occurred in only one patient when using the PHT method and in none by planimetry. CONCLUSIONS Changes in flow rate result in small but clinically insignificant changes in echocardiographic MVA measurement. These methods provide an accurate assessment of MS severity in a majority of patients, independent of changes in flow rate.

Transseptal Catheterization for the Electrophysiologist: Modification with a “View”

First described by Ross and Cope in 1959 and later modi®ed by Brockenbrough, Braunwald and Mullins [1±4] transseptal catheterization was basically introduced as an alternative technique for measuring left atrial and left ventricular pressures. Subsequent introduction of pulmonary artery ̄oatation catheters and retrograde left heart catheterization resulted in a signi®cant decline in the number of transseptal procedures. In fact the numbers reported were as few as 42 in 1973, 45 in 1978, eight in 1984 and 15 in 1985 [5,6]. Interest in the procedure renewed with the dawn of interventional technique for percutaneous balloon dilatation of mitral stenosis. Since then its application has steadily increased with wide utility in a number of procedures like anterograde percutaneous aortic valvotomy, pediatric blade atrial septostomy, decompressing the right atrium in primary pulmonary hypertension and for radiofrequency ablation of left sided arrhythmogenic substrates, such as accessory pathways, left atrial tachycardias, atrial ®brillation and ventricular tachycardia. Transseptal puncture demands a precise understanding of anatomical landmarks on ̄uoroscopy for an indirect assessment of the location of the fossa ovalis [7]. Earlier studies that had used only a single antero-posterior view reported high morbidity and mortality [7]. Lateral ̄uoroscopy allowed orientation of the catheter posterior and inferior to the aorta and reduced inadvertent penetration of the aorta or the pericardial cavity. A right anterior oblique view is also used routinely by many operators for providing an enface view of the atrial septum for de®ning the inferior, posterior and superior borders of the right atrium. A pigtail catheter in ascending aortic root is recommended for de®ning the position of right aortic sinus. The point of puncture lies midway between the posterior border of right atrium and aorta and 1±3 cm below the aortic valve [7]. Transseptal puncture requires a skilled and experienced operator since the associated complications can have disastrous consequences. In a series of 1,279 transseptal catheterizations reported from the Massachusetts general hospital, a total of 17 major complications were reported including cardiac tamponade in 15 patients, systemic emboli and death due to aortic tear in one case each [7]. Indirect information regarding location of fossa ovalis, frequent distortion of atrial anatomy in pathologic hearts, technical expertise and occurrence of complications with unpredictable outcomes provide a steep and a dif®cult learning curve for a beginner. It is desirable that the puncture site be at the fossa ovalis for obviating complications and for facilitating easy manipulation of the catheters. Traditionally transseptal catheterization has relied on ̄uoroscopic guidance in which catheters are guided by its relative position in the cardiac silhouette. However under ̄uoroscopy it can never be clear whether the transseptal needle is in an optimal position. Simultaneous performance of echocardiography can help the operator by allowing direct visualisation of transseptal catheter in relation to atrial septum. Hurrell et al. [8] prospectively evaluated the role of transthoracic two-dimensional echocardiography in cases who were undergoing transseptal puncture. Initial placement of transseptal needle was in the conventional manner guided by ̄uoroscopy. Transthoracic echocardiography was then performed to con®rm or alter the position of the needle to a more desirable location in 33 cases. On the basis of echocardiography, the needle was adjacent to the fossa ovalis in only 17 (52 %) cases, and was not located in the region of fossa ovalis in the remaining 16 (48 %) cases. Misdirections of the needle occurred in several directions Ð anteriorly in 26 %, inferiorly in 37 %, superiorly in 21 % and posteriorly in 16 %,

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.

Echocardiographic spectrum of congenitally unguarded tricuspid valve orifice and patent right ventricular outflow tract

A series of nine consecutive patients with unguarded tricuspid valve orifice as a result of partial or complete agenesis of the valvar tissue and patent right ventricular outflow tract is reported. Clinical manifestations were cyanosis, severe right ventricular failure and incidental echocardiographic detection in a young patient with dilated cardiomyopathy. This series contains the oldest reported patient with this malady, who was misdiagnosed as portal hypertension for 10 years. This study, with possibly the largest number of patients reported so far, sheds some light on the natural history of a rare entity.

Immediate and delayed effects of successful percutaneous transvenous mitral commissurotomy on global right ventricular function in patients with isolated mitral stenosis

Global right ventricular function of the pressure-overloaded right ventricle in patients with mitral stenosis and pulmonary hypertension after successful percutaneous transvenous mitral commissurotomy (PTMC) has not been well-defined. With the use of a recently developed Doppler method for estimating right ventricular function in human beings, we studied 25 consecutive patients with isolated rheumatic mitral stenosis before, immediately after (mean, 40+/-12 h) and at a mean follow-up of 11.5 months after PTMC. Immediately after percutaneous mitral commissurotomy, there was a significant increase in mitral valve area (P = 0.000017) along with a decrease in mean pulmonary pressure (P = 0.001). The index was not affected immediately after successful PTMC (0.70+/-0.25 vs., 0.58+/-0.18; P = 0.06); however, at follow-up of about one year, the index showed a significant decrease (0.697+/-0.28 vs. 0.380+/-0.13; P = 0.0008, n = 24). The change in the index was characterised by a significant prolongation of the right ventricular ejection time, with a decrease in the isovolumic intervals. The Doppler index of combined right ventricular function was significantly correlated to the mean pulmonary artery pressure (r = 0.695, P<0.001) and systolic pulmonary artery pressure (r = 0.60, P = 0.007) before PTMC and also immediately after the procedure; however, at follow-up, the index had no correlation with the Doppler estimated pulmonary artery systolic pressure (r = 0.07). Despite a larger mitral valve area following PTMC, right ventricular isovolumic indices remain abnormal on mid-term follow-up, although global function tends to normalise in two-thirds of the patients.

Unguarded tricuspid orifice and patent right ventricular outflow tract presenting with long-standing severe right heart failure in an adult

An adult female patient presenting with congestive heart failure was detected to have unguarded tricuspid valve orifice, patent right ventricular outflow tract and severe right ventricular systolic dysfunction on cross-sectional echocardiography.

Atrioventricular valve orifice areas in normal subjects: determination by cross-sectional and Doppler echocardiography

Mitral and tricuspid valve orifice areas were determined in 78 healthy subjects (age range, 2 months-50 years; mean, 20 +/- 13 years; 43 male, 35 female; body surface area, 0.25-1.9 m2; mean, 1.24 +/- 0.45 m2) by a combined echo-Doppler approach to establish normal values and their relationship with body surface area. Mitral valve orifice area by direct planimetry (3.37 +/- 1.13 cm2; range, 0.52-5.6 cm2) and by continuity equation (3.62 +/- 1.08 cm2; range, 0.66-5.4 cm2) were similar (r = 0.85, P < 0.0001). Tricuspid valve orifice area (4.07 +/- 1.5 cm2; range 0.62-7.2 cm2) by continuity equation had a close correlation with mitral valve orifice area (r = 0.76, P < 0.001). Mitral and tricuspid valve orifice areas were significantly correlated to body surface area (r = 0.85 and 0.77, respectively), left and right ventricular outflow tract diameters (r = 0.90 and 0.79, respectively) and age (r = 0.70 and 0.61, respectively). These data provide normal values for atrioventricular valve orifice areas in normal subjects with a wide range of body surface area and support the practice of indexing valve area by body surface area.