Quantitative left ventricular angiocardiographic findings in mitral stenosis. Detailed analysis of the anterolateral wall of the left ventricle

Left ventricular diastolic function in mitral stenosis

The assessment of left ventricular (LV) function in the setting of mitral stenosis (MS) has been critically examined for decades. Accurate assessment of aberrations in diastolic function is important as these subjects often present with signs and symptoms of heart failure and pulmonary congestion that cannot be solely explained by the severity of mechanical obstruction. Echocardiographic evaluation of diastolic dysfunction includes an evaluation of reduced LV compliance, diminished restoring forces, and enhanced stiffness, which are challenging in the setting of MS owing to altered hemodynamic loading. Conventional echocardiographic and Doppler measures offer limited information. Novel assessments employing speckle tracking echocardiography are relatively less studied. A more comprehensive assessment including clinical evaluation, identification of concomitant disorders, and comorbidities is particularly warranted in older subjects with degenerative MS to suspect diastolic dysfunction and arrive at optimal medical therapy or intervention. This review provides an overview of etiological, pathophysiological, echocardiographic, and invasive assessment of diastolic dysfunction in the setting of MS, with specific focus on strengths and limitations of available echocardiographic and Doppler techniques.

Impact of percutaneous mitral valvuloplasty on left ventricular function in patients with mitral stenosis assessed by 3D echocardiography

BACKGROUND

The status of intrinsic left ventricular (LV) contractility in patients with isolated rheumatic mitral stenosis (MS) has been debated. The acute changes in loading conditions after percutaneous mitral valvuloplasty (PMV) may affect LV performance. We aimed to examine the acute effects of PMV on LV function and identify factors associated with LV ejection fraction (LVEF) changes, and determinants of long-term events following the procedure.

METHODS

One hundred and forty-two patients who underwent PMV for symptomatic rheumatic MS (valve area of 0.99±0.3cm²) were prospectively enrolled. LV volumes and LVEF were measured by three-dimensional (3D) echocardiography. Long-term outcome was a composite endpoint of death, mitral valve (MV) replacement, repeat PMV, new onset of atrial fibrillation, and stroke.

RESULTS

The mean age was 42.3±12.1years, and 125 patients were women (88%). After PMV, LVEF increased significantly (51.4 vs 56.5%, p<0.001), primary due to a significant increase in LV end-diastolic volume (65.8mL vs 67.9mL, p=0.002), and resultant increase in the stroke volume (33.9mL vs 39.6mL, p<0.001). Changes in cardiac index and systolic pulmonary artery pressure were associated with LVEF changes after PMV. During a mean follow-up period of 30.8months, 28 adverse clinical events were observed. Postprocedural mitral regurgitation, MV area, and mean gradient were independent predictors of composite endpoints.

CONCLUSIONS

In patients with rheumatic MS, PMV resulted in a significant improvement in LV end-diastolic volume, stroke volume and consequently increased in LVEF. Changes in cardiac index and systolic pulmonary artery pressure were associated with LVEF changes after PMV. The predictors of long-term adverse events following PMV were post-procedural variables, including mitral regurgitation, valve area, and mean gradient.

The impact of arterial load on left ventricular performance: an invasive haemodynamic study in severe mitral stenosis

KEY POINTS

A hallmark of mitral stenosis (MS) is the markedly altered left ventricular (LV) loading. As most of the methods used to determine LV performance in MS patients are influenced by loading conditions, previous studies have shown conflicting results. The present study calculated LV elastance, which is a robust method to quantify LV function. We demonstrate that LV loading in MS patients is elevated but normalizes after valve repair and might be a result of reflex pathways. Additionally, we show that the LV in MS is less compliant than normal due to a combination of right ventricular loading and the valvular disease itself. Immediately after valve dilatation the increase in blood inflow into the LV results in even greater LV stiffness. Our findings enrich our understanding of heart function in MS patients and provide a simple reproducible way of assessing LV performance in MS.

ABSTRACT

Left ventricular (LV) function in rheumatic mitral stenosis (MS) remains an issue of controversy, due to load dependency of previously employed assessment methods. We investigated LV performance in MS employing relatively load-independent indices robust to the altered loading state. We studied 106 subjects (32 ± 8 years, 72% female) with severe MS (0.8 ± 0.2 cm(2) ) and 40 age-matched controls. MS subjects underwent simultaneous bi-ventricular catheterization and transthoracic echocardiography (TTE) before and immediately after percutaneous transvenous mitral commisurotomy (PTMC). Sphygmomanometric brachial artery pressures and TTE recordings were simultaneously acquired in controls. Single-beat LV elastance (Ees ) was employed for LV contractility measurements. Effective arterial elastance (Ea ) and LV diastolic stiffness were measured. MS patients demonstrated significantly elevated afterload (Ea : 3.0 ± 1.3 vs. 1.5 ± 0.3 mmHg ml(-1) ; P < 0.001) and LV contractility (Ees : 4.1 ± 1.6 vs. 2.4 ± 0.5 mmHg ml(-1) ; P < 0.001) as compared to controls, with higher Ea in subjects with smaller mitral valve area (≤ 0.8 cm(2) ) and pronounced subvalvular fusion. Stroke volume (49 ± 16 to 57 ± 17 ml; P < 0.001) and indexed LV end-diastolic volume (LVEDVindex : 57 ± 16 to 64 ± 16 ml m(-2) ; P < 0.001) increased following PTMC while Ees and Ea returned to more normal levels. Elevated LV stiffness was demonstrated at baseline and increased further following PTMC. Our findings provide evidence of elevated LV contractility, increased arterial load and increased diastolic stiffness in severe MS. Following PTMC, both LV contractility and afterload tend to normalize.

Valve Pathology in Heart Failure: Which Valves Can Be Fixed?

Heart transplantation has evolved to become the gold standard treatment for patients who have symptoms of severe congestive heart failure associated with end-stage heart disease. From an epidemiologic perspective, this treatment is "trivial" because less than 2800 patients in the United States are offered transplantation because of limitations of age, comorbid conditions, and donor availability. New surgical strategies to manage patients who have severe end-stage heart disease have therefore evolved to cope with the donor shortage in heart transplantation and have included high-risk coronary artery revascularization, cardiomyoplasty, and high-risk valvular repair or replacement.

Outcome following mitral valve replacement in patients with mitral stenosis and moderately reduced left ventricular ejection fraction

BACKGROUND

Some patients with mitral stenosis (MS) have moderately reduced left ventricular (LV) ejection fraction (EF), due to either depressed myocardial contractility or alterations in loading conditions. The effect of moderately reduced LV EF on outcome after mitral valve replacement (MVR) is not known.

METHODS

We studied 16 consecutive patients with LV EF < or = 0.50 and MS without significant mitral regurgitation or other valvular or coronary artery disease (Group I). We selected four controls with LV EF >0.50 for each patient, matched for time of surgery (Group II, n=64). Mean EF in Groups I and II was 0.45 and 0.66, respectively. We compared short- and long-term outcome between the two groups.

RESULTS

There were no perioperative deaths. Group I patients had a higher incidence of in-hospital postoperative heart failure (25% vs. 6%, P=0.02). Mean follow-up was 9 years in both groups. Mean New York Heart Association class improved from 2.4 to 1.7 in both groups. Group I patients had a higher incidence of heart failure deaths (13% vs. 2%, P=0.03) and admissions (40% vs. 13%, P=0.01). There were, however, no differences between Groups I and II in overall mortality (27% vs. 21%), rate of cardiac admissions (69% vs. 53%), or mean Specific Activity Scale Score (2.5 vs. 2.5).

CONCLUSIONS

Although patients with MS and moderately reduced LV EF are at higher risk for heart failure after MVR, overall mortality is not different from that of patients with normal EF. Moderate depression of LV EF should not be a contraindication to MVR for MS.

Changes of left ventricular function after percutaneous balloon mitral valvuloplasty in mitral stenosis with impaired left ventricular performance

The pathophysiological role of mechanical and myocardial factors for impairment of left ventricular performance in mitral stenosis is still not clear. To investigate this controversy, 27 patients of mitral stenosis with left ventricular ejection fraction < 50% were studied. Patients were divided into two groups: Group 1: 20 patients, left ventricular ejection fraction improved to > 50% after valvuloplasty, and Group 2: 7 patients, left ventricular ejection fraction still < 50% after valvuloplasty. The clinical and hemodynamic characteristics were comparable for the two groups before valvuloplasty. Follow-up catheterization done one week later showed similar changes in mitral valve area, cardiac index, pulmonary pressure, left ventricular end-diastolic volume index and systemic vascular resistance between the two groups. However, left ventricular end-systolic volume was significantly decreased after valvuloplasty in Group 1 but not in Group 2, resulting in significantly higher ejection fraction in Group 1 than in Group 2. Postoperatively, regional wall motion scores were lower in Group 1 than in Group 2 (2.0 +/- 0.6 vs. 2.7 +/- 0.5 at the anterolateral wall, P = 0.002; 1.9 +/- 0.6 vs. 2.9 +/- 0.4 at the posterobasal wall, P = 0.0003). Most of our mitral stenosis patients with impaired left ventricular ejection fraction showed improvement after mitral valvuloplasty had released the mechanical obstruction. However, in some patients, impaired ejection fraction persisted after valvuloplasty, suggesting the mechanism of myocardial failure. Thus, both myocardial and mechanical factors play important roles in the pathogenesis of left ventricular ejection performance impairment.

Immediate and long-term effect of mitral balloon valvotomy on left ventricular volume and systolic function in severe mitral stenosis

To determine the immediate and long-term effect of mitral balloon valvotomy (MBV) on left ventricular (LV) volume and function, we studied 17 patients (mean age 27 +/- 9 years) with severe mitral stenosis undergoing MBV by cardiac catheterization and angiography before and immediately after MBV and at mean 12 months later. At baseline, LV end-diastolic volume index (EDVI) was reduced. Ten patients had EDVI < or = 55 ml/m2, and four patients (23.5%) had LV ejection fraction < 50%. EDVI increased from 60 +/- 17 ml/m2 to 66 +/- 17 ml/m2 (p < 0.05) immediately after MBV and increased further to 72 +/- 16 ml/m2 (p < 0.05) later. Stroke volume index increased from 34 +/- 10 ml/m2 to 41 +/- 12 ml/m2 (p < 0.05) immediately after MBV and increased further to 50 +/- 11 ml/m2 (p < 0.001) later. LV end diastolic pressure increased from 12 +/- 5 mm HG to 16 +/- 4 mm HG (p < 0.05) immediately after MBV and fell to 13 +/- Hg at follow-up. LV ejection fraction increased from 57 +/- 7% to 62 +/- 6% (p < 0.05) immediately after MBV and 71 +/- 8% later (p < 0.001). Mean systolic ejection rate increased from 82 +/- 35 ml/sec to 101 +/- 48 ml/sec (p < 0.05) immediately after and 165 +/- 81 ml/sec later (p < 0.05). Systemic vascular resistance fell from 1887 +/- 525 dyne/sec/cm-5 to 1280 +/- 231 dyne/sec/cm-5 (p < 0.001) at follow-up. We conclude that the LV end-diastolic volume and systolic function are reduced in patients with mitral stenosis, and the LV end-diastolic volume is increased immediately after MBV and continues to increase at follow-up 12 months later; the LV ejection performance improves after successful MBV because of an increase in end-diastolic LV volume (preload) and reduction of SVR.

Acute changes in left ventricular function after percutaneous transluminal mitral valvuloplasty

Percutaneous balloon mitral valvuloplasty (PBMV) has been shown to induce an immediate increase in the left ventricular end-diastolic volume, which increase, in turn, has been attributed to an increase in left ventricular compliance. We studied 51 patients, 41 women and 10 men, who underwent PBMV, and were in sinus rhythm before and after the procedure. Heart rate did not vary significantly. There were increases in left ventricular end-diastolic volume (97.5 +/- 25.6 vs 112.7 +/- 25.7 ml/m2, P < 0.001), left ventricular end-diastolic pressure (8.7 +/- 3.0 vs 9.7 +/- 4.3 mmHg, P = 0.04), and both left ventricular systolic pressure and stress (118 +/- 20.5 vs 123 +/- 23.2 mmHg and 468 +/- 129 vs 580 +/- 164 mmHg; P = 0.04 and P < 0.001, respectively). The elastic stiffness constant did not vary (16.2 +/- 1.9 vs 15.7 +/- 1.9 (dimensionless units), P = 0.2). The increase in volume seemed to be particularly important when the ventricle appeared to be "shrunken" before PBMV. This increase was still present after a 1 year follow up. Thus, PBMV determines an increase in both end-diastolic volume and pressure, so that the left ventricle appears to move along a single pressure-volume curve. This enlargement evokes the Frank Starling mechanism, and improves systolic performance. Since it is still evident after a 1 year follow up, some concern may arise when a simultaneous volume overload is present, as in aortic insufficiency.

Effects of balloon mitral valvuloplasty on left ventricular muscle function

Echocardiographically determined ventricular load and performance were compared in 40 consecutive patients with severe mitral stenosis before and 24 h after successful and uncomplicated balloon mitral valvuloplasty in order to clarify the role of loading conditions in causation of reduced left ventricular ejection fraction. After valvuloplasty, mitral valve area increased 2-fold. A modest increase in ejection fraction (53 +/- 11% to 57 +/- 8%, P = 0.021) occurred with an insignificant increase in end-diastolic volume (44 +/- 10 to 48 +/- 16 ml/m2, P = 0.063) and no change in wall stress (61 +/- 19 to 59 +/- 19 kdynes/cm3, P = 0.85) (10(5) dynes = 1 N). There was no correlation between changes in fractional shortening and wall stress (r = 0.07) and between changes in end-diastolic volume and fractional shortening (r = 0.12). Contractile performance estimated by a performance-afterload relation was unchanged after the valvuloplasty. Factors other than a change in loading conditions might be responsible for a modest improvement in ejection performance following mitral valvuloplasty.

Assessment of cardiac volumes and left ventricular mass by cine computed tomography before and after mitral balloon commissurotomy

We used cine computed tomography (CT) to determine whether decreased mitral valve gradients and pulmonary artery pressures resulted in decreased right ventricular and atrial volumes after percutaneous mitral balloon commissurotomy (MBC). In patients treated for severe mitral stenosis, previous studies have shown that after the mitral valve gradient decreases, the left atrial volume is reduced and left ventricular stroke volume is increased. The effects of commissurotomy on right heart chamber sizes have been difficult to assess with angiography and echocardiography. Moreover, in follow-up studies performed after surgery, changes in cardiac chamber volumes occurring after the mitral valve gradient and pulmonary pressure are reduced are confounded by the effects of thoracotomy. Our group has previously demonstrated that cine CT can accurately measure both left and right cardiac chamber volumes. We studied 11 female patients before, immediately after, and at 1 year after MBC, and 9 female control subjects of comparable age. To assess cardiac chamber volumes, we used cine CT. To assess the effects of MBC, we used cardiac catheterization and Doppler echocardiography.(ABSTRACT TRUNCATED AT 250 WORDS)

Frequency, cause and effect on operative outcome of depressed left ventricular ejection fraction in mitral stenosis

To assess the incidence, pathophysiology and influence on operative outcome of a depressed left ventricular (LV) ejection fraction (EF) in patients with mitral stenosis (MS), demographic, hemodynamic and cineangiographic data on 72 patients (16 men, 56 women, aged 19 to 75 years) with isolated MS were reviewed. Of the 45 who had mitral commissurotomy or replacement, operative course and functional class before and after surgery were assessed. Of the 72 patients, 21 (29%) had an LVEF < or = 0.50. These 21 were similar to the 51 with an LVEF > 0.50 in age, gender, heart rate, intracardiac pressures, transvalvular gradient and valve area, but they had larger LV end-diastolic (79 +/- 19 [mean +/- SD] vs 59 +/- 15 ml/m2, p < 0.001) and end-systolic volumes (46 +/- 13 vs 23 +/- 8 ml/m2, p < 0.0001). Of the 45 subjects undergoing surgery, operative outcome was similar in the 14 with a depressed and the 31 with a normal LVEF. Thus, about 1/3 of patients with isolated MS have a depressed LVEF. Compared with those with MS and a normal LVEF, these subjects have hemodynamic derangements of similar severity, but they have larger LV end-diastolic and end-systolic volumes, suggesting that impaired LV contractile function or excessive afterload (rather than diastolic underfilling), or both, is the cause of a low LVEF. Those with an LVEF < or = 0.50 who undergo valve surgery have a similar operative outcome as those with an LVEF > 0.50.

Replacement of chordae tendineae using expanded polytetrafluoroethylene (ePTFE) sutures during mitral valve replacement in patients with severe mitral stenosis

Since September 1991, 20 patients with mitral stenosis underwent mitral valve replacement and chordal replacement with expanded polytetrafluoroethylene (ePTFE) sutures. The continuity between the papillary muscles and the mitral annulus was maintained by four mattress sutures of ePTFE, which connected the stumps of the papillary muscle heads to the mitral annulus at the 2, 4, 8, and 10 o'clock positions. Low profile bileaflet prosthetic valves were inserted. There was no mortality either in-hospital or during follow-up. There was no valve related morbidity, such as valve structural failure, thromboembolism, anticoagulant related hemorrhage, prosthetic valve endocarditis, or posterior left ventricular rupture. The technique of replacing chordae tendineae is described in detail.

Left ventricular diastolic pressure-volume response immediately after successful percutaneous transvenous mitral commissurotomy

The left ventricular (LV) diastolic pressure-volume response after percutaneous transvenous mitral commissurotomy (PTMC) was investigated to determine whether it was related to the baseline conditions of the left ventricle. Left ventriculography was performed, and the measurements of LV pressure were obtained in 32 patients before and after PTMC. Mitral valve area increased from 1.0 +/- 0.3 to 1.9 +/- 0.4 cm2 (p < 0.005) after PTMC, which caused a decrease in left atrial mean pressure (14.8 +/- 5.9 to 7.4 +/- 2.7 mm Hg; p < 0.005). LV end-diastolic pressure increased in all patients 5 minutes after PTMC. However, patients could be divided into 2 groups according to the following changes in LV end-diastolic pressure 20 minutes after PTMC: In 22 patients, LV end-diastolic pressure returned to the near-baseline level 20 minutes after PTMC (before 5.0 +/- 2.2, 5 minutes after 8.6 +/- 3.1, and 20 minutes after 6.3 +/- 2.5 mm Hg) with a significant increase in LV end-diastolic volume index (64 +/- 12 to 74 +/- 14 ml/m2; p < 0.001) and augmentation of LV stroke volume index (39 +/- 9 to 47 +/- 11 ml/m2; p < 0.001). However, in the remaining 10 patients with a larger LV volume (> 80 ml/m2) and reduced ejection fraction (< 50%) at baseline, LV end-diastolic pressure further increased 20 minutes after PTMC (before 5.5 +/- 2.8, 5 minutes after 7.8 +/- 2.7, and 20 minutes after 11.0 +/- 2.9 mm Hg) without significant changes in LV volume.(ABSTRACT TRUNCATED AT 250 WORDS)

Cross-sectional echocardiographic left ventricular geometry in rheumatic mitral stenosis

The ultrastructural myopathic changes and deranged left ventricular contractile function have been reported in patients with rheumatic mitral stenosis. It is not clear if as a result of these myopathic changes, global left ventricular myocardial remodelling occurs to alter its normal elliptical shape in the absence of qualitative segmental asynchrony. To study the left ventricular cavity shape independent of chamber size, cross-sectional echocardiographically measured longest long axis (L) of the left ventricular cavity in the apical four-chamber view and short axis diameters at the level of tips of the mitral leaflets in the parasternal long axis view (D-1), of the basal cavity (D-2) and the apical segment (D-3) in the apical four-chamber view at end-diastole and their ratio, were studied in 20 patients with isolated rheumatic mitral stenosis. Twenty healthy volunteers matched for age, sex, heart rate, height and body surface area provided the normal control data. The patients with mitral stenosis had shorter long axis diameter (7.2 +/- 0.7 vs 7.9 +/- 0.5 cm, p < 0.001) and greater short axis/long axis diameter ratios at every level with the most pronounced change in the apical segment of the cavity (D-3/L 0.49 +/- 0.09 vs 0.40 +/- 0.05, p < 0.001). Left ventricular end-diastolic sphericity index was also markedly increased in the patients with mitral stenosis (0.57 +/- 0.09 vs 0.40 +/- 0.05, p < 0.001).(ABSTRACT TRUNCATED AT 250 WORDS)

Excessive vasoconstriction in rheumatic mitral stenosis with modestly reduced ejection fraction

OBJECTIVES

The primary hypothesis examined was that underfilling due to inflow obstruction accounts for modestly depressed ejection performance in mitral stenosis. Having found little evidence to support this hypothesis, we sought to determine other factors that might differentiate patients with different levels of ejection performance.

METHODS

Ventricular load and performance were compared in two groups of patients before and immediately after successful balloon valvuloplasty that was not complicated by mitral regurgitation: those in whom prevalvuloplasty ejection fraction was > or = 0.55 (group I, n = 10) and those in whom it was < 0.55 (group II, n = 11).

RESULTS

Before valvuloplasty, mitral valve area was less in group II (0.65 cm2) than in group I (0.84 cm2, p = 0.02), but end-diastolic pressure (12 vs. 12 mm Hg in group I), end-diastolic wall stress (46 vs. 44 kdynes/cm2 in group I) and end-diastolic volume (152 vs. 150 ml in group I) were not less in group II, nor were these variables significantly reduced compared with those of a normal control group. In group II, end-systolic volume was larger (77 vs. 55 ml in group I, p = 0.001) and cardiac output was less (3.1 vs. 3.6 liters/min in group I, p = 0.03), possibly owing to higher systemic vascular resistance (2,438 vs. 1,921 dynes.s.cm-5 in group I, p = 0.05) and end-systolic wall stress (273 vs. 226 kdynes/cm2 in group I, p = 0.06), although mean arterial pressure in the two groups was similar (91 vs. 84 mm Hg in group I, p = 0.22). Group II patients also had higher values for pulmonary vascular resistance (712 vs. 269 dynes.s.cm-5 in group I, p = 0.03) and mean pulmonary artery pressure (47 vs. 29 mm Hg in group I, p = 0.02) despite similar values for mean left atrial pressure (20 vs. 18 mm Hg in group I, p = 0.35). After valvuloplasty, mitral valve area increased by 2.5- and 3-fold, respectively, in group I (to 2.1 cm2) and group II (to 2.0 cm2). Modest increases in left ventricular end-diastolic pressure, end-diastolic stress and end-diastolic volume (+9%) after valvuloplasty were statistically significant only for group II. End-systolic wall stress did not decline in either group II (281 kdynes/cm2) or group I (230 kdynes/cm2), and ejection fraction failed to increase significantly (0.49 to 0.51 for group II and 0.62 to 0.61 for group I) after valvuloplasty. Contractile performance estimated with a preload-corrected ejection fraction-afterload relation was within or near normal limits in all 19 patients in whom it was assessed.

CONCLUSIONS

Excessive vasoconstriction may account for the higher afterload, lower ejection performance and lower cardiac output observed in a subset of patients with mitral stenosis because contractile dysfunction could not be detected and left ventricular filling--which was not subnormal despite severe inflow obstruction--improved only modestly after valvuloplasty.

Reduced left ventricular compliance in human mitral stenosis. Role of reversible internal constraint

BACKGROUND

The mechanisms of depressed left ventricular (LV) pump performance in human mitral stenosis (MS) remain poorly understood, because reduced filling alone affects many hemodynamic measurements. Therefore, pressure-volume relations were examined in nine subjects with MS and compared with eight age-matched normal controls.

METHODS AND RESULTS

Data were obtained by conductance catheter/micromanometer technique with transient inferior vena cava occlusion used to alter load and generate pressure-volume relations. In a subset of patients (n = 5), data were obtained both acutely and at 3 months (n = 4) after balloon valvuloplasty. MS patients had reduced cardiac output (3.3 +/- 0.9 versus 5.6 +/- 1.7 l/min) and end-diastolic volume (68.0 +/- 6.9 versus 115 +/- 31 ml) versus controls (p less than 0.001), with a mean transvalvular gradient of 14 +/- 6 mm Hg and estimated valve area of 0.6 +/- 0.2 cm2. Systolic function as assessed by the end-systolic pressure-volume relation was virtually the same in MS and control subjects. In contrast, end-diastolic pressure-volume relations in MS were consistently shifted leftward and had an increased slope (lower compliance) at matched pressure ranges (6.5 +/- 3.0 versus 2.2 +/- 0.53 ml/mm Hg at a mean diastolic pressure of 8 mm Hg, p less than 0.001). This change was not a result of reduced LV filling or probably of increased right heart loading. Valvuloplasty acutely returned chamber compliance to near normal, a change that was sustained at 3-month follow-up. Systolic function was little altered at this time.

CONCLUSIONS

These data indicate an impairment of diastolic function in human MS that can be acutely reversed by balloon valvuloplasty. Lowered LV compliance probably results from a functional restriction caused by ventricular attachment to a thickened and immobile valve apparatus.

Left ventricular volumes and function immediately after balloon mitral valvoplasty

To evaluate acute changes in left ventricular volumes and function immediately after successful percutaneous balloon mitral valvoplasty, twenty young patients with isolated rheumatic mitral stenosis (male 9, female 11, mean age 22 +/- 6 years) were studied. The area of the orifice of the mitral valve following valvoplasty, increased from 0.97 +/- 0.27 cm2 to 2.46 +/- 0.75 cm2 (P less than 0.001). No significant change was observed in left ventricular end-diastolic volumes (117 +/- 27 ml to 119 +/- 29 ml, P greater than 0.10), end-systolic volumes (51 +/- 21 ml to 50 +/- 20 ml, P greater than 0.10), ejection fraction (0.57 +/- 0.10 to 0.58 +/- 0.10, P greater than 0.10) and left ventricular meridian wall stress (68 +/- 20.10(3) dynes/cm2 to 65 +/- 14, P greater than 0.10) immediately after valvoplasty. There was no acute change in heart rate, left ventricular end-diastolic pressure, cardiac index and grade of mitral regurgitation. Patients with depressed left ventricular ejection fraction (less than or equal to 0.55, n = 10) and those with normal ejection fraction (greater than 0.55, n = 10) had similar baseline left ventricular end-diastolic volumes and showed no significant change in volumes and ejection fraction after the procedure, although the former group had a greater orificial area after valvoplasty (P less than 0.05). We conclude that an acute increase in the orifice of the mitral valve in patients with rheumatic mitral stenosis is not associated with any significant change in left ventricular volumes and function.

Effects of percutaneous mitral valvuloplasty on left ventricular mass and volume

The response of left ventricular (LV) geometry to altered loading conditions after mitral valvuloplasty has been incompletely described. Therefore, 15 patients with rheumatic mitral stenosis were studied using quantitative 2-dimensional echocardiography a mean of 1 +/- 2 months before and 11 +/- 5 months after percutaneous balloon mitral valvuloplasty. Mitral valve area (Gorlin) increased in all patients, from 1.0 +/- 0.3 to 1.9 +/- 0.5 cm2 (p less than 0.01). Mitral regurgitation (1+/4+) developed in 3 patients, and increased by 1 grade in 1 patient as a consequence of mitral valvuloplasty. After valvuloplasty, there were significant increases in LV end-diastolic volume (69 +/- 22 to 82 +/- 26 ml, p less than 0.01), stroke volume (34 +/- 13 to 46 +/- 19 ml, p less than 0.05) and mass (181 +/- 46 to 200 +/- 42 ml, p less than 0.005). LV end-systolic volume and ejection fraction did not change significantly. LV mass-to-volume ratio was unchanged (5.6 +/- 1.5 to 5.8 +/- 1.4 g/ml, p = not significant). Quantitatively similar results were obtained when these changes were indexed to body surface area. Thus, successful mitral valvuloplasty was associated with significant increases in LV end-diastolic volume and mass. These findings suggest that increased preload may be a stimulus to myocardial growth.

Severity of rheumatic mitral stenosis in children

Clinical, hemodynamic and operative findings of 125 children, up to the age of 12 years, were analysed to determine if the severity of pulmonary venous and arterial hypertension correlated with the severity of rheumatic mitral stenosis. Moderately severe to severe pulmonary venous and arterial hypertension was found in almost three-quarters of the patients. Operative findings indicated critical mitral stenosis in 69% of the cases. In India, following rheumatic fever, some patients follow an unusually rapid course in developing mitral stenosis severe enough to require operative treatment, even at the age of six years.

Detection and quantitation of ischemic left ventricular dysfunction using a new video intensity technique for regional wall motion evaluation

Eighty patients with ischemic heart disease and 17 normal subjects were evaluated for left ventricular regional wall motion by means of a new method. The wall motion analysis is based on video intensity. This technique uses a temporally sliding analysis to evaluate the cardiac cycle in 100 msec intervals. Presence of coronary artery disease was defined as more than 50% measured diameter stenosis. Wall motion abnormalities in regions perfused by stenotic vessels were most common in early diastole (76%). Sensitivity of this method at rest in patients with coronary artery disease was 79.7% (p less than 0.0001) and overall accuracy was 84.2% (p less than 0.0001). Abnormalities in both systole and diastole were more common in regions perfused by severe lesions (greater than 75%) than in those perfused by moderately stenotic (less than 75%) vessels (p less than 0.05). A comparison of the new method with phase and amplitude analysis was performed in 15 patients and with two-frame analysis in 40 patients. This new method yielded a higher sensitivity than either of the other two methods.

Quantitative frame by frame analysis of regional contraction and lengthening on left ventricular cineangiograms: application to the study of normal left ventricles and left ventricles with mitral valve prolapse

This work attempted to study the segmental wall motion on left ventriculograms, in terms of segmental shortening, velocity of segmental shortening, and temporal sequences of various events in systole as well as in diastole. The ability of such a method to characterize patterns of normal regional wall motion and to detect mild abnormalities such as isolated asynchronisms, was tested on two groups of patients. Group I included 25 patients presenting evidence of a normal left ventricle (LV) after left heart catheterization. Group II consisted of 21 patients suffering from an isolated pure idiopathic mitral valve prolapse (MVP), with no mitral insufficiency and with an unaffected global LV function. In all patients left ventriculography was filmed in the right anterior oblique view at a rate of 50 frames/s. For each patient a cycle was chosen, distant from any premature beat, with acceptably contrasted outlines, and a quantitative frame by frame study of the motion of 10 segments was performed using a semiautomated method derived from the Stanford method. In the control group (Group I), analysis of the segmental motion by means of this method demonstrates a mild nonuniformity of the normal wall motion. This is principally marked by a stronger and faster contraction in anterolateral segments (segments 7, 8, 9) and by a shorter duration of the contraction in this region. In contrast the MVP group (Group II), exhibited a frank asynergy of the anterolateral region occurring from end systole to early diastole.(ABSTRACT TRUNCATED AT 250 WORDS)

Global left ventricular function and regional wall motion in pure mitral stenosis

Global left ventricular function (LVF) and segmental wall motion of the left ventricle are registered in 113 patients presenting a pure mitral stenosis (MS) and in a control group of 50 individuals. The segmental wall motion is measured on the end-diastolic-end-systolic frames of the left ventricle, obtained from right anterior oblique (RAO) monoplane cineangiography. Measurement of the segmental wall shortening is performed using the Stanford method. Group 1 includes 68 patients (60% of the total number of patients studied). These patients show no pathological contraction abnormality. In this group, the global LVF is not different from the control group. Group 2 includes 45 patients (40% of the total) for whom contraction abnormalities are present: anterior hypokinesis in 20% of the cases (anterior area mean shortening (AAS) = 18 +/- 8%; p less than 0.001 vs. group 1 and control group), and posterior hypokinesis in 20% of the cases (posterior area mean shortening (PAS) = 9.8 +/- 5.8%, p less than 0.001 vs. group 1 and control group). In this group, global LVF is impaired; ejection fraction (EF) = 0.57 +/- 0.1% (p less than 0.001 vs. group 1); velocity of circumferential fiber shortening (VCF) = 1 +/- 0.3 circ/s (p less than 0.001 vs. group 1); enddiastolic pressure (EDP) = 11 +/- 5 mmHg (p less than 0.01 vs. group 1). Segmental contraction abnormalities appear to be the main factor involved in the global LVF impairment. Segmental wall motion abnormalities could be related to subvalvular fibrosis, or LV filling difficulties, or principally, to a possible interplay between the right and the left ventricles.

Determination of left ventricular residual function by analysis of post-extrasystolic beat in mitral stenosis

Residual function of the left ventricle was assessed in 25 patients with mitral stenosis and a normal left ventriculogram. The post-extrasystolic beat (R2) in sinus rhythm (nine patients) and the first beat after an early beat (R2) in atrial fibrillation (16 patients) were analysed angiocardiographically. Five subjects with a normal heart (controls) were also studied. The results are expressed as percentage changes in left ventricular contractility from the beat preceding the extra beat (R1) to the beat R2. In the control group the mean changes from R1 to R2 were: end diastolic volume +68.3% (increase), end systolic volume -21.7% (decrease), ejection fraction +36.2%, mean systolic ejection rate +22.1%, and mean velocity of circumferential fibre shortening +31%. A significant increase in proportional systolic shortening of all left ventricular axes was found in R2 compared with R1. In five patients with sinus rhythm and nine with atrial fibrillation the results fell within the normal range. In the remaining patients the beat R2 indicated signs of poor left ventricular function. The mean changes from R1 to R2 in the patients with sinus rhythm and those with atrial fibrillation were respectively: end diastolic volume +47.8% and +36.6%, end systolic volume +20% and +27%, ejection fraction +12.5% and +6.2%, mean systolic ejection rate -23.3% and -30.2%, and mean velocity of circumferential fibre shortening -25.5% and -39.2%. The increase in the left ventricular axial systolic shortening was not significant. Thus analysing a post-extrasystolic beat in sinus rhythm of the beat following an early beat with a long diastole in atrial fibrillation is a valuable method of determining the residual function in patients with mitral stenosis who have a normal left ventriculogram in basic rhythm.

Left ventricular performance in patients with coexistent mitral stenosis and aortic insufficiency

Isolated mitral stenosis and isolated aortic insufficiency impose unique and opposite loading conditions on the left ventricle. To assess these combined effects, hemodynamic and angiographic factors were compared among normal subjects and patients with isolated mitral stenosis, isolated aortic insufficiency or combined mitral stenosis and aortic insufficiency. Left ventricular end-diastolic volume index was lower in patients with combined lesions and severe or moderate aortic insufficiency than in patients with isolated severe or moderate aortic insufficiency (138 +/- 19 versus 206 +/- 20 cc/m2 and 87 +/- 5 versus 145 +/- 22 cc/m2, respectively) (p less than 0.05 for both). Left ventricular end-diastolic and end-systolic volume indexes were normal in two-thirds of patients with combined lesions and moderate or severe aortic insufficiency, whereas these indexes were high in all but one patient with isolated moderate or severe aortic insufficiency. Among patients with moderate or severe aortic insufficiency, 8 of 14 with isolated insufficiency had a reduced ejection fraction or circumferential fiber shortening rate compared with 5 of the 9 patients with combined lesions. Among patients with isolated aortic insufficiency, left ventricular end-systolic wall stress and end-diastolic and end-systolic volume indexes were higher (p less than 0.05) in those with reduced ejection performance than in those with normal ejection performance. These variables did not differ between patients with reduced or normal ejection performance in the group with combined lesions. The contractile index (ratio of end-systolic wall stress to end-systolic volume index) was significantly depressed in patients with severe aortic insufficiency in the groups with isolated aortic insufficiency or combined lesions.(ABSTRACT TRUNCATED AT 250 WORDS)

Right ventricular performance in mitral stenosis

Until recently, the dynamic geometry and pump function of the pressure-overloaded right ventricle in patients with mitral stenosis and pulmonary hypertension had not been well defined. With use of a recently developed method for calculating right ventricular volume in human beings, seven normal subjects and eight patients with mitral stenosis and pulmonary hypertension had right ventricular performance assessed from computer-analyzed biplane right ventriculograms. Patients with mitral stenosis has elevated values for systolic right ventricular pressure (mean +/- standard error of the mean 25 +/- 2 for normal subjects, 57 +/- 6 mm Hg for patients with mitral stenosis), but normal values for right ventricular end-diastolic volume index (normal 95 +/- 11, patients 81 +/- 9 ml/m2) and ejection fraction (normal 0.49 +/- 0.02, patients 0.58 +/- 0.04). Comparison of right ventricular function using group performance curves of stroke work versus end-diastolic volume revealed the slope of the mitral stenosis line to be significantly greater than the normal line. A plot of right ventricular stroke volume versus end-diastolic volume, which removes pressure from the performance index, revealed that the two groups have similar performance. Left ventricular function measured by ejection fraction was reduced in mitral stenosis. These data suggest that the right ventricle performs normally in patients with mitral stenosis with moderate pulmonary hypertension and maintains normal size and ejection fraction.

Left ventricular function in severe pure mitral stenosis as seen at the Kenyatta National Hospital

Twenty-one consecutive Black African patients with severe pure mitral stenosis were evaluated hemodynamically. It was found that advanced mitral stenosis presents itself in Kenya at a very young age (22.9 +/- 9.6 years, mean +/- S.D.), with all but three patients under thirty. Left ventricular angiography demonstrated significant impairment of left ventricular function with 50% of patients having abnormally low valves (mean ejection fraction 0.50 +/- 0.11). This diminished ejection fraction was related primarily to diffuse hypokinesia and an increased endsystolic volume. There was a significant deterioration of ejection fraction with increasing age which could not be correlated to increased severity of mitral stenosis or pulmonary hypertension. It is proposed that the diffuseness of the myocardial involvement and its progression with age in a young population without coronary artery disease represents the resolution of the acute inflammatory process of rheumatic fever in diffuse fibrosis of the myocardium and/or an occlusive vasculitis.

Ultrastructural and histological study of left ventricular myocardium in mitral stenosis. Correlations with angiocardiographic indices of left ventricular function (in 11 observations)

Left ventricular myocardial biopsies were performed during surgery in 11 patients with pure and isolated mitral stenosis. Patients had undergone a preoperative angiocardiographic study of left ventricular function. Biopsy specimens were examined with the light and electron microscope. Myocyte cell diameter was normal (20 +/- 1.6 mu). Lesions existed which were probably degenerative, including anarchy and irregularities of sarcomeres, Nemaline Myopathy-type Z line changes and alterations of intercalated discs. A moderate fibrosis was found in the interstitial spaces with very few histiocytes. The coincidence planimetry study of the interstitial spaces showed a 37 +/- 5.5% increase compared to a control group with no fibrosis (23 +/- 1.5%, p less than 0.01). The angiocardiographic indices of left ventricular function were all decreased. Only four subjects had normal left ventricular function (EF greater than or equal to 55%). Nevertheless, it was not possible to establish a significant correlation between the extent of fibrosis and the decrease of left ventricular function. Although left ventricular fibrosis could be one of the factors responsible for decreased myocardial function, it is not sufficient to explain the changes of left ventricular function which are rather frequently observed in mitral stenosis.

Hemodynamic assessment of the Ionescu-Shiley pericardial xenograft in the mitral position

While the very low thrombogenicity without anticoagulant therapy and generally good durability of the lonescu-Shiley bioprosthesis has been demonstrated, further hemodynamic assessment is necessary. The present study assessed cardiac function and heterograft performance during right and left heart catheterization at rest and exercise (three to six months postoperation) of eight patients with severe mitral stenosis and/or regurgitation prior to surgery. We found, comparing pre- and postoperative resting values, that mean pulmonary artery pressure decreased (32 +/- 2.7 to 22 +/- 3.5 mm Hg; P < 0.02), cardiac index increased (2.1 +/- 0.09 to 2.5 +/- 0.13 liters/min/m2; P < 0.01), pulmonary wedge pressure decreased (21 +/- 2.3 to 13 +/- 1.8 mm Hg; P < 0.01), and the clinical status (NYHA) improved markedly. Mean diastolic gradient across the pericardial xenograft was 6.1 +/- 1.1 mm Hg at rest and 14.6 +/- 2.3 mm Hg on exercise. The calculated xenograft surface area was 1.7 cm2 at rest and 2.0 cm2 during exercise. No regurgitation was detected in seven of eight patients. Thus, mitral lonescu-Shiley bioprosthesis provide excellent heterograft function.

Left ventricular function in rheumatic mitral stenosis. Clinical echocardiographic study

Echocardiography was used to examine the extent and significance of impairment in left ventricular function in 20 patients with rheumatic mitral stenosis. Indices of left ventricular performance--normalised mean rate of circumferential fibre shortening (Vcf), ejection fraction, normalised posterior wall velocity, and stroke volume were reduced. The impairment in left ventricular function was related to the degree of functional disability (NYHA), right ventricular dilatation, and left atrial enlargement. Vcf was inversely related to both the internal right ventricular diameter (r=-0.767, P less than 0.001) and the degree of left atrial enlargement (r=-0.554; P less than 0.05). The normalised velocity of the interventricular septum and the maximum systolic and diastolic endocardial velocities were also reduced. These results suggest that abnormalities in contractility of left ventricular myocardium are responsible for the impaired myocardial function in patients with mitral stenosis and that such impairment is clinically significant.

Correlative study of regional left ventricular histology and contractile function

In 110 patients with documented coronary artery disease, transmural biopsy of the anteroapical region of the left ventricle was performed during aortocoronary bypass grafting. Biopsy specimens were semiquantitatively graded microscopically for myocardial fibrosis as an indicator of chronic ischemic damage. Preoperatively, systolic wall motion of the region from which the biopsy specimen was taken was semiquantitatively graded as showing normal motion, hypokinesia, akinesia or dyskinesia on ventriculography. Wall motion-histologic correlations, taking into account both electrocardiographic evidence of anterior infarction and ST-T abnormalities, were then established. Overall, there was fair agreement (72 percent) between functional and histologic assessment of the left ventricular region evaluated, both qualitatively (normal versus abnormal, 72 percent agreement) and quantitatively (degree of abnormality, correlation coefficient 0.66, P = 0.005). The 22 patients with electrocardiographic evidence of anterior infarction had various degrees of abnormal regional motion and myocardial fibrosis. Discordance between wall motion and histologic findings was most common (50 percent of instances) in the 34 patients with anterior ST-T changes without infarction and generally was manifest as abnormal motion with normal histologic features. By contrast, normal motion and abnormal histologic features represented the most common type of discordance (22 percent of instances) in the 54 patients without either anterior infarction or ST-T deviation. These data provide a basis for inference of myocardial morphologic features (fibrosis) from assessment of ventriculographic wall motion and the electrocardiogram. They may thus be useful in predicting the potential functional benefits of bypass grafting of coronary arteries supplying abnormally contractile segments of the left ventricle.

Echocardiographic assessment of left ventricular function in mitral valve disease

Echocardiography was used to study left ventricular size and contraction in 90 patients with isolated mitral valve disease--47 patients with mitral stenosis, 26 with mixed mitral valve disease and 89 with mitral regurgitation. Left ventricular measurements included the end-diastolic internal dimension (LVIDd), mural thickness (PWTd), an index of circumferential myocardial contraction--fractional shortening (see article)--and stroke volume (LVSV). The left ventricle was abnormally small only when mitral stenosis was severe. Reduced myocardial contraction was common in patients with rheumatic valvular heart disease but was rarely severe. In mitral regurgitation without left ventricular failure, measurements were characteristic of volume overload with increases in LVIDd, LVSV and PWTd which were related to the severity of regurgitation. In other diseases, left ventricular failure is usually associated with reduced myocardial contraction (FS) but in mitral regurgitation with failure, myocardial contraction (FS 32%) did not differ significantly from normal (34%). The reduction in afterload caused by mitral regurgitation probably increases myocardial contraction and may lead to underestimation of the severity of myocardial impairment. Also potentially misleading was severe mitral regurgitation with normal values for LVIDd and LVSV (three patients). When the distinction between cardiomyopathy with secondary mitral regurgitation and primary mitral regurgitation was difficult clinically, echocardiography could usually make the distinction by demonstrating severe reduction of myocardial contraction with a slight or moderate increase in LVSV.

Use of the electrocardiogram as an aid in screening for left ventricular aneurysm

Attempting to cull from a population of patients with coronary artery disease or cardiomyopathy, a subgroup in whom left ventriculography might most reasonably be performed in search of a surgically resectable ventricular aneurysm, the electrocardiograms (ECGs) and ventriculograms of 96 patients were analyzed. This study was conceived to test the value of the ECG as an initial screening technique. Patients with normal ventricular contractile motion in the presence of coronary artery disease rarely showed ST segment elevation exceeding 2 mm in any lead, and even more rarely showed Q waves in corresponding leads. All patients with well defined left ventricular aneurysms had at least 1 mm ST segment elevation, and the majority (73%) had ST elevation of 2 mm or greater; in 80% of these, there were associated Q waves in the same lead. In patients with only local areas of hypocontractility, the frequency of ST segment elevation with concomitant Q waves was significantly less (approximately 50%) than that seen in patients with aneurysms. It is concluded that patients with suspected or proven coronary disease who fail to demonstrate ST segment elevation are unlikely to have ventricular aneurysms and, thus, would receive little diagnostic benefit from left ventriculography. The presence of ST segment elevation, with or without associated Q waves in the same leads, is a helpful screening sign, raising the possibility of a surgically remediable lesion such as a ventricular aneurysm, but similar electrocardiographic patterns are also seen in patients with non-operable localized or generalized disorders of contraction. Having discovered ST elevation, then, left ventriculography becomes a reasonable next step - when otherwise indicated - in delineating the type of contractile disorder as well as the amount of adequately functioning muscle.

Analysis of left ventricular function in response to afterload changes in patients with mitral stenosis

In order to assess left ventricular function in patients with rheumatic mitral stenosis, left ventricular function curves (plotting stroke work index vs left ventricular end-diastolic pressure) were constructed using angiotensin to augment, and nitroprusside to reduce, afterload. Hemodynamic responses to these alterations in afterload were measured. Resting ejection fractions and qualitative assessment of left ventricular angiographic contraction abnormalities were also determined. Changes in left ventricular end-diastolic pressure following afterload interventions could be linearly related to changes in mean aortic pressure, but mitral valve gradients were unaffected. Afterload reduction with nitroprusside did not augment cardiac output. Afterload elevation with angiotensin significantly depressed both cardiac output and calculated mitral valve areas. Patients with normal resting ejection fractions evidenced normal ventricular function curves and those with depressed ejection fractions showed flat or declining function curves. Contraction abnormalities, generally in the posterobasal area, correlated well with abnormal left ventricular function curves.

Intraaortic balloon counterpulsation in patients in cardiogenic shock, medically refractory left ventricular failure and/or recurrent ventricular tachycardia

Of the 27 patients described, 23 were in cardiogenic shock, 2 had severe left ventricular failure, and 2 had medically refractory ventricular tachycardia. Utilizing intraaortic counterpulsation, adequate systemic blood pressure was initially restored in 19 patients. Nine of these were subsequently weaned from circulatory assistance, but only three were discharged from the hospital and are currently alive. The remaining 10 patients who derived initial benefit from circulatory assistance were balloon-dependent in that they could not be weaned from circulatory assistance. Eight of these patients subsequently underwent cardiac catheterization; four had inoperable disease. The remaining four patients underwent surgery for either resection of the area of infarction and/or for myocardial revascularization; only one survived to subsequently leave the hospital. Ventricular volumes were abnormal and ejection fractions were below 30 per cent in all the patients in cardiogenic shock except one who underwent cardiac catheterization and ultimately died. Ejection fractions were greater than 30 per cent in the two patients with cardiogenic shock who were weaned from balloon support and survived to leave the hospital without surgery. Both of these patients had inferior myocardial infarction. The data obtained from this experience suggest that intraaortic counterpulsation is a very useful adjunct to currently existing medical measures to treat both cardiogenic shock and medically refractory left ventricular failure but that most patients have such extensive disease that they can neither be weaned from balloon support nor undergo successful infarctectomy or myocardial revascularization.