Catheterization and Cardiovascular Diagnosis 22:21-24 (1 991)
Atrial Septa1 Occlusion Improves the Accuracy of Mitral Valve Area Determination Following Percutaneous Mitral Balloon Valvotomy George A. Petrossian, MD, E. Murat Tuzcu, MD, Andrew A. Ziskind, MD, Peter C. Block, MD, and lgor Palacios, MD We investigated the impact of the atrial communication on the mitral valve area calculation after percutaneous mitral balloon valvotomy in 17 patients (15 women, 2 men; mean age 56 2 4 years). The hemodynamic measurements and mitral valve area calculations were performed with and without balloon occlusion of the atrial septal puncture site. The mitral valve area determined with balloon occlusion was significantly smaller than the mitral valve area determined without occlusion (1.6 f 0.1 vs. 1.9 f 0.1 cm2, P < 0.01), and was similar to the echocardiographically determined valve area (1.6 f 0.1 an2). This decrease in the calculated mitral valve area with occlusion was associated with a decrease in the measured cardiac output, without a change in the mitral valve gradient or the diastolic filling period. Occlusion of the atrial septal puncture site may permit more accurate determination of the mitral valve area and thus provide a better reference point for future comparison should the question of restenosis arise. Key words: ASD, mitral stenosis, percutaneous mitral balloon valvotomy
INTRODUCTION
Immediately after percutaneous mitral balloon valvotomy (PMV) 10-30% of patients have a left to right atrial shunt detected by oximetry [1,2]. A greater percentage of patients have a left-to-right shunt that can be detected with more sensitive techniques [3-51. Shunting may alter the post-PMV hemodynamic measurements and therefore result in an incorrect calculation of the mitral valve area. We designed this study to determine the impact of the atrial communication on the calculated mitral valve area by measuring the hemodynamic parameters and calculating the mitral valve area in 17 patients after PMV with and without balloon occlusion of the atrial septal puncture site.
METHODS Patient Population
The study group consisted of 17 consecutive patients with symptomatic mitral stenosis. All patients were in New York Heart Association functional class I11 or IV. They underwent PMV between January and June 1990, using the antegrade double balloon technique as previously described [6,7]. There were 2 men and 15 women, mean age 56 2 4 years. All patients had transthoracic two-dimensional and Doppler echocardiography 1 day before PMV and within 0 1991 Wiley-Liss, Inc.
24 hr of the procedure. Mitral valve area was determined by planimetric measurement of the mitral valve orifice in the parasternal short axis view [S]. Cardiac Catheterization
In the catheterization laboratory, blood samples from the superior vena cava, pulmonary artery, and femoral artery were obtained in the baseline state for oxygen saturation measurements. A left-to-right shunt through the atrial septum was diagnosed when a stepup 2 7 % between the oxygen saturation of the superior vena cava and pulmonary artery blood samples was present [9]. After transeptal puncture, simultaneous left atrial and left ventricular pressures and thermodilution cardiac outputs were obtained. Before placement of the valvotomy balloons, the atrial septum was dilated with a 5-mm diameter balloon catheter. Care was taken in the selection and placement of the dilating balloons in order to avoid inadvertent dilation of the atrial septum. We tried to avoid separation of the proximal portion of the dilating
From the Department of Medicine, Cardiac Unit, Massachusetts General Hospital, Boston, Massachusetts.
Received July 9, 1990; revision accepted September 12, 1990. Address reprint requests to Dr. Igor Palacios, Cardiac Unit, Massachusetts General Hospital, Boston, MA 021 14.
22
Petrossian et al.
Fig. 1. This 7-Fr. balloon tip catheter is inflated in the left atrium and pulled against the atrial septum to occlude the puncture site.
balloons and guide wires during inflation and sequential withdrawal of the completely deflated balloons to minimize trauma to the atrial septum [ I]. After PMV, repeat measurement of the simultaneous left atrial and left ventricular pressures, oxygen saturation, and cardiac output were performed. Before removing the transseptal sheath from the left atrium a 7-Fr. catheter with an inflated balloon tip was pulled against the atrial septa1 puncture site to occlude it (Fig. 1). After 3 min of occlusion, the same hemodynamic parameters were determined again. The mitral valve area after PMV was determined with and without balloon occlusion of the atrial septum puncture site using the Gorlin formula. In addition, as a third method of mitral valve area calculation, we have used the corrected cardiac output. The cardiac output without balloon occlusion was corrected for any stepup in oxygen saturation between the superior vena cava and pulmonary artery, even if it was
Atrial Septa1 Occlusion Improves the Accuracy of Mitral Valve Area Determination Following Percutaneous Mitral Balloon Valvotomy George A. Petrossian, MD, E. Murat Tuzcu, MD, Andrew A. Ziskind, MD, Peter C. Block, MD, and lgor Palacios, MD We investigated the impact of the atrial communication on the mitral valve area calculation after percutaneous mitral balloon valvotomy in 17 patients (15 women, 2 men; mean age 56 2 4 years). The hemodynamic measurements and mitral valve area calculations were performed with and without balloon occlusion of the atrial septal puncture site. The mitral valve area determined with balloon occlusion was significantly smaller than the mitral valve area determined without occlusion (1.6 f 0.1 vs. 1.9 f 0.1 cm2, P < 0.01), and was similar to the echocardiographically determined valve area (1.6 f 0.1 an2). This decrease in the calculated mitral valve area with occlusion was associated with a decrease in the measured cardiac output, without a change in the mitral valve gradient or the diastolic filling period. Occlusion of the atrial septal puncture site may permit more accurate determination of the mitral valve area and thus provide a better reference point for future comparison should the question of restenosis arise. Key words: ASD, mitral stenosis, percutaneous mitral balloon valvotomy
INTRODUCTION
Immediately after percutaneous mitral balloon valvotomy (PMV) 10-30% of patients have a left to right atrial shunt detected by oximetry [1,2]. A greater percentage of patients have a left-to-right shunt that can be detected with more sensitive techniques [3-51. Shunting may alter the post-PMV hemodynamic measurements and therefore result in an incorrect calculation of the mitral valve area. We designed this study to determine the impact of the atrial communication on the calculated mitral valve area by measuring the hemodynamic parameters and calculating the mitral valve area in 17 patients after PMV with and without balloon occlusion of the atrial septal puncture site.
METHODS Patient Population
The study group consisted of 17 consecutive patients with symptomatic mitral stenosis. All patients were in New York Heart Association functional class I11 or IV. They underwent PMV between January and June 1990, using the antegrade double balloon technique as previously described [6,7]. There were 2 men and 15 women, mean age 56 2 4 years. All patients had transthoracic two-dimensional and Doppler echocardiography 1 day before PMV and within 0 1991 Wiley-Liss, Inc.
24 hr of the procedure. Mitral valve area was determined by planimetric measurement of the mitral valve orifice in the parasternal short axis view [S]. Cardiac Catheterization
In the catheterization laboratory, blood samples from the superior vena cava, pulmonary artery, and femoral artery were obtained in the baseline state for oxygen saturation measurements. A left-to-right shunt through the atrial septum was diagnosed when a stepup 2 7 % between the oxygen saturation of the superior vena cava and pulmonary artery blood samples was present [9]. After transeptal puncture, simultaneous left atrial and left ventricular pressures and thermodilution cardiac outputs were obtained. Before placement of the valvotomy balloons, the atrial septum was dilated with a 5-mm diameter balloon catheter. Care was taken in the selection and placement of the dilating balloons in order to avoid inadvertent dilation of the atrial septum. We tried to avoid separation of the proximal portion of the dilating
From the Department of Medicine, Cardiac Unit, Massachusetts General Hospital, Boston, Massachusetts.
Received July 9, 1990; revision accepted September 12, 1990. Address reprint requests to Dr. Igor Palacios, Cardiac Unit, Massachusetts General Hospital, Boston, MA 021 14.
22
Petrossian et al.
Fig. 1. This 7-Fr. balloon tip catheter is inflated in the left atrium and pulled against the atrial septum to occlude the puncture site.
balloons and guide wires during inflation and sequential withdrawal of the completely deflated balloons to minimize trauma to the atrial septum [ I]. After PMV, repeat measurement of the simultaneous left atrial and left ventricular pressures, oxygen saturation, and cardiac output were performed. Before removing the transseptal sheath from the left atrium a 7-Fr. catheter with an inflated balloon tip was pulled against the atrial septa1 puncture site to occlude it (Fig. 1). After 3 min of occlusion, the same hemodynamic parameters were determined again. The mitral valve area after PMV was determined with and without balloon occlusion of the atrial septum puncture site using the Gorlin formula. In addition, as a third method of mitral valve area calculation, we have used the corrected cardiac output. The cardiac output without balloon occlusion was corrected for any stepup in oxygen saturation between the superior vena cava and pulmonary artery, even if it was
