Left ventricular filling and ejection fraction after successful percutaneous balloon mitral valvuloplasty

International Journal of Cardiology 59 (1997) 243–246

Left ventricular filling and ejection fraction after successful percutaneous balloon mitral valvuloplasty ¨ ¨ ¨ Remzi Karaoguz ¨ ¨ Pamir*, Fatih Ertas¸, Dervis¸ Oral, Halil Gumus ¨ ¨ ¸, Kenan Omurlu, ˇ Gulgun Cardiology Department, Faculty of Medicine, Ankara University, Ankara, Turkey Received 12 November 1996; accepted 11 February 1997

Abstract The effect of percutaneous balloon mitral valvuloplasty (PBMV) on left ventricular (LV) filling and ejection fraction (EF) still remains controversial. We evaluated LV filling and EF in 23 patients (19 women and four men, mean age 35.669.6, range 17–56 years) with mitral stenosis (MS) and sinus rhythm immediately before and after successful PBMV not complicated with significant mitral regurgitation and arrhythmia during left ventriculography. After PBMV mean mitral valve area increased from 1.460.2 to 2.260.3 cm 2 (P,0.01), mean mitral valve gradient (MVG) decreased from 18.665.7 to 6.963.2 mmHg (P,0.01) and mean left atrial pressure (LAP) decreased from 26.068.2 to 12.365.2 mmHg (P,0.01). We did not determine any change in EF (before PBMV 61.869.3% and after PBMV 61.867.6% (P.0.05)). Heart rate did not change significantly before and after valvuloplasty (P.0.05). Despite the decrease in LAP and MVG, the early diastolic filling fraction of left ventricle did not change (before PBMV 59.567.5%, after PBMV 57.868.9% (P.0.05)). Also, we did not determine any increase in LV end diastolic volume index (before PBMV 89.9627.7 cm 3 / m 2 and after PBMV 84.6620.9 cm 3 / m 2 (P.0.05)). However, LV end diastolic pressure increased significantly after PBMV (from 6.663.0 to 11.364.9 mmHg (P,0.01)). We conclude that in patients with MS, LV diastolic performance is impaired and LV EF does not change acutely after PBMV.  1997 Elsevier Science Ireland Ltd. Keywords: Mitral stenosis; Balloon mitral valvuloplasty; Left ventricular function

1. Introduction The principle pathophysiologic abnormality in mitral stenosis (MS) is the impaired left ventricular (LV) diastolic filling especially in the early rapid filling phase (first third) of diastole. This filling abnormality is due to primarily mechanical valve *Corresponding author. Mesa Koru Sitesi, Gul ¨ Blok, No: 29, 06530 Ankara, Turkey.

stenosis itself. Also, the left atrial pressure, blood flow through the valve, diastolic filling time, and the diastolic performance of the left ventricle affect the LV filling in MS [1]. On the other hand, some patients with isolated MS have a depressed LV ejection fraction (EF) due to insufficient preload, afterload mismatch, high right ventricular pressure and primary LV contractile dysfunction [2–4]. The effect of percutaneous balloon mitral valvuloplasty (PBMV) on LV filling and EF is controversial.

0167-5273 / 97 / $17.00  1997 Elsevier Science Ireland Ltd. All rights reserved PII S0167-5273( 97 )02959-8

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In the present study, we evaluated LV diastolic filling and EF in the patients with MS immediately before and after successful PBMV.

hemodynamic calculations. All measurements were done immediately before and after successful PBMV.

2.3. Balloon mitral valvuloplasty procedure 2. Materials and methods

2.1. Patient selection Twenty-three patients (19 women and four men, mean age 35.669.6, range 17–56 years) with MS in sinus rhythm who underwent PBMV were selected. Patient selection was based on the echocardiographic, hemodynamic, and clinical status of the patients. Exclusivity criteria were; (1) mixed valvular disease, (2) atrial and ventricular arrhythmias during left ventriculographies, (3) coronary artery disease, (4) left atrial thrombus, (5) mitral regurgitation (grade 2 or more) before and after PBMV, (6) systemic arterial hypertension and (7) exposure to a known cardiotoxin (i.e. heavy ethanol consumption, cocaine abuse, doxorubicin therapy or previous mediastinal irradiation).

2.2. Echocardiographic, angiographic and hemodynamic evaluation All patients have had moderate MS. Mean mitral valve area was 1.460.2 cm 2 , and mean valvular gradient was 18.665.7 mmHg before valvuloplasty. Mitral valve area (MVA) was calculated by echocardiography with the planimetric method. LV volumes and LV EF were calculated by using digital ventriculographic images on the 308 right anterior oblique projection. Diastolic filling period was divided into three equal parts: namely; early, mid- and late diastole. The blood volume entering the left ventricle during early, mid- and late diastole, which indicated the filling properties of each part were calculated. The early diastolic filling fraction was calculated with this formula: 1 First ] of diastole (cm 3 /m 2 )x100 3 ]]]]]]]]]] End diastolic volume (cm 3 /m 2 ) Left ventricular end diastolic pressure (LVEDP), the mean left atrial pressure (LAP) and the mean mitral valve gradient (MVG) were measured with

The valvuloplasty was performed with the Inoue monoballoon technique. The success was defined as a decrease in mitral valve gradient .50% and an increase in MVA .0.5 cm 2 after PBMV.

2.4. Statistics All data were expressed as mean6S.D. The influence of valvuloplasty on the hemodynamic variables and MVA was evaluated with the Wilcoxon signed-ranks matched-pairs test. Spearman rank correlation test was used for the correlation analysis among parameters. A value of P,0.05 was considered statistically significant.

3. Results

3.1. Results of balloon mitral valvuloplasty After PBMV mean MVA increased from 1.460.2 to 2.260.3 cm 2 (P,0.01), MVG decreased from 18.665.7 to 6.963.2 mmHg (P,0.01) and LAP decreased from 26.068.2 to 12.365.2 mmHg (P, 0.01). The mean LVEF of our patients was within normal range (LVEF was ,50% in only two patients). There was no correlation between LVEF and the mean pulmonary artery pressure (33.9612.96 mmHg, range 10–62 mmHg) (P.0.05). We did not determine any change in EF (before PBMV 61.869.3% and after PBMV 61.867.6% (P.0.05)). Heart rate did not change significantly before and after valvuloplasty (before PBMV 94.8617.2 and after PBMV 90.2616.2 beats / min (P.0.05)).

3.2. Results of LV filling characteristics Despite the decrease in LAP and MVG, the early diastolic filling fraction of left ventricle did not change (before PBMV 59.567.5%, after PBMV 57.868.9% (P.0.05)). There was a correlation between LVEF and the early diastolic filling fraction

G. Pamir et al. / International Journal of Cardiology 59 (1997) 243 – 246 Table 1 Results of the echocardiographic and hemodynamic parameters

MVA (cm 2 ) MVG (mmHg) LAP (mmHg) EDFF (%) LVEDVI (cm 3 / m 2 ) EF (%) LVEDP (mmHg)

Before PBMV

After PBMV

P-value

1.460.2 18.665.7 26.068.2 59.567.5 89.9627.7 61.869.3 6.663.0

2.260.3 6.963.2 12.365.2 57.868.9 84.6620.9 61.867.6 11.364.9

P,0.01 P,0.01 P,0.01 P.0.05 P.0.05 P.0.05 P,0.01

PBMV, percutaneous balloon mitral valvuloplasty; MVA, mitral valve area; MVG, mitral valve gradient; LAP, left atrial pressure; EDFF, early diastolic filling fraction (first 1 / 3 of diastole (cm 3 / m 2 )3100 / end diastolic volume (cm 3 / m 2 )); LVEDVI, left ventricle end diastolic volume index; EF, ejection fraction; LVEDP, left ventricle end diastolic pressure.

at baseline and after PBMV (P,0.05). We did not determine any increase in LV end diastolic volume index (LVEDVI) (before PBMV 89.9627.7 cm 3 / m 2 and after PBMV 84.6620.9 cm 3 / m 2 (P.0.05)). However, LVEDP increased significantly after PBMV (from 6.663.0 to 11.364.9 mmHg (P,0.01)). There were no correlations between LVEF and MVA or LVEDP at baseline and after PBMV (P.0.05). Results are shown in Table 1.

4. Discussion Mitral stenosis impedes left ventricular filling. It is expected and shown in some studies [5–8] that after removal of stenosis, left ventricular filling must be improved. However, in this study we did not determine any change in early LV filling fraction and end diastolic volume index after PBMV like some other studies [1,9–12]. On the other hand we observed that LVEDP increased significantly after PBMV. These findings may be related to the fact that LV filling is also affected by the other diastolic properties of LV. There are some hypotheses to explain the LV diastolic abnormalities in patients with MS [3,6]: (1) immobilization and atrophy of posterobasal region of LV due to a restriction or tethering effect of scarred, calcified and immobile mitral apparatus, (2) endomyocardial fibrosis from rheumatic inflammation and / or vasculitis, (3) elevated right heart loading and thus abnormal right-left heart interactions. There is a conflict on reversal of LV diastolic abnormalities after PBMV. In a previous study, just

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after PBMV while end diastolic volume was increased, end diastolic pressure was not changed significantly. So the authors suggested that diastolic abnormalities can be acutely reversed by PBMV [6]. However, the number of the patients enrolled in this study was not enough (five patients) to make a conclusion. Endomyocardial fibrosis as shown in pathology studies [13] may also play a role in reduced diastolic distensibility, so valvuloplasty should not acutely alter the structure of the myocardium. Grover-McKay et al. [10] showed an increase in right ventricular end diastolic volume (RVEDV) by using cine computed tomography after PBMV. Elevated RVEDV after the procedure may affect LV diastolic performance. Harrison et al. [1] suggested that values before and after PBMV for LVEDV, LVEDP, diastolic filling time and the percentage of diastolic filling in the first third of diastole were not altered by the procedure. But depending on Doppler data, Thomas et al. [14] suggested that LV chamber compliance may decrease acutely after PBMV because of the LV ischemia or myocardial trauma produced by the procedure. So there is a discrepancy between hemodynamic and Doppler data after PBMV. Since we could not measure LV volumes and pressures simultaneously by conductance catheter micromanometer technique, we could not calculate left ventricular compliance. However, we observed that although LVEDV had not changed, LVEDP increased significantly acutely after PBMV. The decrease of MVG after PBMV should also be related with the increase of the left atrial chamber compliance. So we think that LV diastolic performance is impaired just after PBMV and the increase of LVEDP may result from myocardial factors, elevated right heart loading and thus abnormal right-left heart interactions. In previously published literature, the rate of left ventricular dysfunction in patients with MS is about 30% [2]. The mean LVEF of our patients was within normal range because, they had moderate MS and we had selected the patients with sinus rhythm. In the present study, we primarily evaluated the diastolic properties of left ventricle while assessing the systolic function by EF only, which was shown to be unchanged after PBMV. It was thought that the relatively low number of patients with baseline LV dysfunction (2 patients (8.6%)) may be responsible

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for unchanged LVEF after PBMV. There are some contrary results about the effect of PBMV on LV systolic performance. While several studies [8,11,12] have shown no change in LVEF, the others [5,9] have suggested the improvement in ejection performance following PBMV.

5. Conclusion In patients with MS, LV diastolic performance is impaired and LVEF does not change acutely after PBMV.

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