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Echocardiographic Evaluation of Patients with Primary Pulmonary Hypertension Before and After Atrial Septostomy

NILDA ESPINOLA-ZAVALETA, M.D., JESUS VARGAS-BARRON, M.D.,

CANDACE KEIRNS, M.D., ANGEL ROMERO CARDENAS, M.D., JORGE ISAAC TAZAR, M.D., JOSE MIGUEL CASANOVA, M.D.,

JORGE GASPAR, M.D., F.A.C.C., and JULIO SANDOVAL, M.D., F.A.C.C. Department of Echocardiography, Instituto Nacional de Cardiologia “Ignacio Chavez,” Mexico, D.F., Mexico

Objectives: To characterize the early changes in right ventricular [right ventricle (RV)lgeometry and function, as assessed by two-dimensional (2-D) and Doppler echocardiography, after balloon-dilation atrial septostomy (BDAS) in patients with severe primary pulmonary hypertension (PPH).Back- ground. Suruival in PPH is to a great extent dependent on the functional status of the RV. BDAS recently has been shown to improve functional class and hemodynamics in patients with PPH nonresponsive to conventional vasodilator treatment. Methods: Ten patients with severe PPH who underwent BDAS were studied with transthoracic and transesophageal 2-0 and Doppler echocar- diogra,phy. RV dimensions were measured in the apical four-chamber view. Continuous-wave Dopp- ler echocardiography was used to obtain peak velocity of tricuspid regurgitation. Transesophageal echocardiography (TEE) primarily was used for the follow-up of the atrial septa1 defects (ASDs). Results: I n the early post-BDAS studies, right atrial and ventricular dimensions significantly decreased in all patients (P < 0.05). Global right ventricular wall motion ( R W M ) also improved. RV percent change in area after septostomy inversely correlated with the changes in RV systolic area ( r = -0.75; P < 0.05) and also with the baseline (preprocedure) values of RVpercent change in area (r = - 0.77; P < 0.05). Neither RV wall thickness nor the degree of tricuspid regurgitation were modified significantly after the procedure. Conclusions: BDAS in the setting of severe PPH results in moderate and salutary changes i n geometry and function of the RV as assessed by 2 -0 echocardiography. These changes mainly appear to be the result of the decompression effect of atrial septostomy. (ECHOCARDIOGRAPHY, Volume 16, No. 7, Part 1, October 1999)

atrial septostomy, primary pulmonary hypertension, tramesophageal echocardiography.

Severe pulmonary hypertension invariably results in abnormalities in cardiac structure and function. Progressive right ventricular (RV) dysfunction in patients with primary pulmonary hypertension (PPH) is associated with a poor short-term progno~is.l-~ Contemporary

Address for correspondence and reprint requests: Dr. Jesus Vargas-Barron, Department of Echocardiography, Insti- tuto Nacional de Cardiologia “Ignacio Chavez,” Juan Badi- a n o No. 1, Colonia Seccion XVI, Tlalpan 14080, MCxico. Fax: 525-573-0994.

medical treatment of PPH mainly is directed to alleviate the existing pulmonary microvascular obstruction (ie., anticoagulants, oral vasodila- tors, chronic infusion of prostacyclin, and lung transplant) with an improvement in RV dysfunction as a secondary g ~ a l . ~ - ~ Although prostacyclin and transplant are effective for patients who are nonresponders to oral vasodila- tors, the worldwide application of these interventions is limited by technical difficulties and cost.

Several recent studiess-I2 have evaluated the

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ESPINOLA-ZAVALETA. ET AL.

potential role of atrial septostomy in the treatment of selected patients with PPH. These studies have shown that both blade-balloon atrial septostomy (BBAS) and/or balloon-dilation atrial septostomy (BDAS) can be performed successfully in patients with advanced disease and can bring about significant clinical and hemodynamic impr0vement.~-'4 In the ini- tial report from our institution,12 a significant improvement in RV hernodynamics and exercise tolerance was documented after the BDAS procedure. However, the extent to which chronic RV compensatory changes regress after BDAS has not been defined. Accordingly, the present study was designed to evaluate the early changes in RV geometry and function in patients with severe pulmonary hypertension after BDAS as assessed by the echocardiographic findings before and after this procedure.

Methods

Study Patients

From November 1994 to September 1997 we performed 22 procedures of BDAS in 15 consecutive patients with established diagnosis of PPH. The BDAS procedure and the clinical response in these patients have been reported elsewhere.12 The ten patients reported here represent those in whom a technically adequate two-dimensional (2-D) and/or transesophageal echocardiographic (TEE) studies before and after the procedure were available.

The patients underwent BDAS as part of their treatment on the basis of severe and symptomatic pulmonary arterial hypertension with RV dysfunction or recurrent syncope despite medical therapy (including diuretic drugs, anticoagulation therapy, and digoxin). Also, during their diagnostic study, all patients had and did not respond to an acute vasodilator trial with adenosine and nifedipine.l5

Before the procedure, an anatomic atrial sep- tal defect (ASD) or a patent foramen oval and a poor left ventricular (LV) function in these patients were ruled out by 2-D echocardiography. Also, patients considered candidates for the procedure had to have a baseline arterial oxy-

gen saturation (SaO,) greater than 80% at rest and have a hematocrit greater than 35% to enable them to maintain adequate systemic oxygen transport after the procedure. The exercise endurance of the patients was assessed through a 6-minute walk test16 before and after (i.e., before discharge) the procedure. All procedures were approved by our Institutional Committee for Clinical Investigation. The risks involved and the potential benefits of BDAS were explained to the patients and their writ- ten consent was obtained.

BDAS

BDAS at our institution has been previously described.12 Briefly, the procedure is performed under standard right and left heart catheterization. The transeptal puncture is performed through the Mullins sheath and dilator with a Brockenbrough needle through which a circu- lar-end Inoue guidewire is passed to the left atrium (LA). Over this guidewire, a first dilation with a 4-mm semirigid dilator is done and then exchanged for successive Mansfield bal- loons to perform a progressive dilation of the orifice in a step-by-step manner ranging from 8 to 16 mm. At each step (4, 8, 12, and 16 mm), we carefully assess the concomitant changes that occur in the following variables: RV end- diastolic pressure (RVEDP), LV end-diastolic pressure (LVEDP), and arterial SaO,%. The final size of the defect is determined by the changes produced in the last two variables; as an endpoint we attempt to maintain arterial SaO, greater than 75% and to keep LVEDP no higher than 18 mmHg. Cardiac output before and after the procedure are calculated by the indirect Fick principle using assumed oxygen consumption values.

All patients are monitored in an intensive care setting for at least 48 hours after the procedure. In the absence of significant bleeding, heparin is started again 6 hours after BDAS and all patients are treated subsequently with oral anticoagulants to maintain an Interna- tional Normalized Ratio of 2.5-3.0. They also are advised to use long-term nocturnal oxygen therapy as part of their treatment.

All survivors were followed clinically and

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noninvasively with transthoracic echocardiography (TTE) or TEE at our outpatient clinic every 3 months. Exercise tolerance was reas- sessed at each of these intervals, and during these evaluations, particular care was taken to detect spontaneous closure of the defect based on any of the following findings: (1) reappear- ance of symptoms or signs of RV failure, (2) spontaneous “improvement” of arterial oxygen saturation, and (3) echocardiographic evidence of closure of the interatrial defect.

Echocardiography

Transthoracic and transesophageal 2-D Dopp- ler echocardiography were characterized in patients before and after BDAS using a Hewlett- Packard Sonos 1500 imaging system. Trans- thoracic studies were performed with a 3.5- MHz transducer and transesophageal studies with a 5-MHz biplane or multiplane transducer. Patients were imaged during quiet res- piration in the left lateral decubitus position. For TEE examination the oropharynx was anesthetized with 20% lidocaine spray to sup- press the gag reflex and retching. Preprocedure echocardiograms were obtained within 2 weeks before BDAS in all patients. Postintervention studies were performed at 5.5 2 3 months after the procedure. In addition, in patients going through follow-up TEE with color flow imaging we used intravenous agitated saline solution contrast injections to evaluate accurately the presence and size of the intracardiac shunts (Fig. 1).

Measurements were made on three repre- sentative beats and the results were averaged. All echocardiographic studies were recorded on VHS videocassettes for subsequent evaluation by two expert cardiologist-echocardiographers who were unfamiliar with the clinical status of patients. Results were taken by consensus. The following variables were analyzed: (1) Right atrial transverse diameters were measured at 0” in ventricular diastole, and the diameter of the main pulmonary artery (PA) was measured at 70” in systole (Fig. 2). (2) The RVED area (RVEDA) and end-systolic area (RVESA) were measured in a four-chamber view by tracing the endocardial edges of the RV at the plane of

Figure 1. Transesophageal image at 62” showing that the diameter of the atrial septostomy is 4.11 m m (arrow). RA indicates right atrium; LA, left atrium.

the tricuspid valve at end-diastole and end- systole (Fig. 3). Both areas were divided by height to correct for differences in body size. Images were considered technically adequate if no dropout in the endocardial outlines along the interventricular septum and RV free wall was observed. RV size was characterized only as a planar area. (3) The RV percent change in area was calculated from the areas of the RV in end-diastole and end-systole as RV percent change in area = 100 X (RVEDA - RVESA)/ RVEDA. This measure correlates closely with RV ejection fraction as measured by radionu- clide angiography.l7JS (4) Global RV wall motion (RVWM) was assessed qualitatively. It was considered to be normokinetic if there was obvious normal systolic wall thickness and inward endocardial motion and hypokinetic when abnormal systolic wall thickness and/or inward endocardial motion existed. Hypokine- sis was graded as either mild or moderate.17-19 RV wall thickness was measured at end-diastole in a four-chamber view that allowed best definition of the RV free wall. (5) To calculate systolic PA pressure, transthoracic continuous- wave Doppler echocardiography positioned from an apical four-chamber image was used to obtain regurgitant tricuspid flow velocity. The Bernoulli equation (V2 X 4, where V = maximum flow velocity) was applied to determine

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regurgitant area was noted; the ratio of the maximal regurgitant jet area to the right atrial area then was obtained. When this ratio was >34% the tricuspid regurgitation was considered severe. If the ratio was <34% the regurgitation was considered mild to moderate.22 Pulmonary regurgitation was investigated in transesophageal images at 0" and 110". (7) Pericardial effusion presence was determined from parasternal long-axis and short-axis views.

Statistical Analysis

Comparisons between baseline and postpro- cedure data were made using the Student t-test

Figure 2. Two-dimensional (2-0) transesophageal images at 0" and 112" demonstrate how the right ventricular (RV) transverse diameter (upper panel) and main pulmonary artery (PA) diameter (lower panel) are measured. RA indicates right atrium; RV, right ventricle; LA, left atrium; and MAP, main pulmonary artery.

the maximum tricuspid regurgitant pressure gradient.20 The pulmonary arterial systolic pressure was estimated by multiplying this gradient by 1.23, the correction factor that ap- proximates the pulmonary pressure obtained by echocardiography to those determined during cardiac catheterization.21 (6) The degree of tricuspid regurgitation was evaluated by color Doppler echocardiography from transesopha-

formed on the maximal area of the regurgitant signals to obtain the regur&ant jet area. The area of the right atrium (RA) also was measured in the same frame in which the maximal

geal images at O" and 'lanirnetrY was Per- Figure 3. Transesophageal four-chamber image at 00 showing the measurement of right ventricular (RV) diastolic (upper panel) and systolic (lower panel) areas. RA indicates right atrium; LA, left atrium; and LV, left ventricle.

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for paired data. Significance was defined as a two-tailed P < 0.05. We also used standard analysis for linear regression. Descriptive variables are presented as mean value 2 SD.

Results

Clinical, Functional, and Hemodynamic Findings

Patients included eight women and two men with a mean age of 33 % 9.5 years (range 22-51 years). The demographic, functional, and hemodynamic characteristics of the patients before and after atrial septostomy are summa- rized in Tables I and 11.

Before the procedure, all patients were markedly symptomatic because of exercise-related shortness of breath (ten patients), chest pain (five patients), and syncope or near syncope (four patients). Eight of the ten patients had clinical evidence of systemic venous con- gestion (i.e., peripheral edema, ascitis, and hepatomegaly). At diagnostic catheterization, all patients had severe pulmonary arterial hypertension and RV dysfunction as evident by a mean PA pressure of 60 t 13 mmHg; a cardiac index of 2.34 ? 0.44, and a RVEDP of 14.5 % 6 mmHg. The baseline mean arterial SaO, was 92 t 4%.

After atrial septostomy, the New York Heart Association (NYHA) functional class and exercise capacity improved in all but one patient. In addition, a significant improvement in most of the hernodynamic variables was shown immediately after the procedure (see Table 11).

Echocardiographic Findings Before Atrial Septostomy

Values before atrial septostomy for transverse right atrial, RV, and PA diameters as well as those for RV systolic and diastolic indexed areas were all increased. The RV mean percent change in area was diminished in most of the patients (Table 111). RVWM was normal in two patients, mild hypokinesis was present in six patients, and moderate hypokinesis was present in two patients. RV wall thickness was increased in all patients. The pulmonary arterial systolic pressure also was increased in all cases (113 t 19.1 mmHg). The correlation between direct measurements of PA systolic pressure at diagnostic catheterization and noninvasive estimates based on continuous-wave Doppler echocardiography measurements was not significant ( r = 0.41; P = ns.) .

Table I

Demographic and Clinical Characteristics of the Patients Before and After Atrial Septostomy

NYHA Functional Class 6-min Walk Test (m)

Patient No. Age (y) Sex Size (mm) Before After Before After Septostomy

1 5 1 M 8 4 2 50 216 2 35 F 8 2 2 380 380 3 43 F a 4 2 70 108 4 25 M 12 3 2 150 360 5 24 F 6 4 3 25 108 6 22 F 12 4 2 25 108 7 37 F 8 4 2 25 162 8 23 F 16 4 2 50 180 9 32 F 12 4 2 25 180

10 35 F 6 4 2 0 108 Mean ? SD 33 t 9.5 9.6 2 3.2 3.7 -f 0.7 2.1 2 0.3* 80 2 113 191 -f 102*

M = male; F = female; NYHA = New York Heart Association. *P < 0.05 (paired t-test).

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Table I1

Hemodynamic Data Before and Immediately After Atrial Septostomy

Cardiac Index RVEDP LVEDP Mean PAP (mmHg) (L/min per m2) (mmHg) (mmHg) 5a02%

Patient No. Before After Before After Before After Before After Before After

1 66 68 2.62 2.80 26 25 4 9 94 87 2 50 46 2.10 2.40 8 8 4 8 96 94 3 76 61 3.26 4.22 12 10 2 3 90 79 4 66 61 2.80 4.50 10 3 0 8 89 85 5 45 42 1.84 2.47 24 22 10 11 86 70 6 45 42 1.90 2.80 12 - 4 4 87 74 7 52 47 1.97 3.59 14 11 8 12 94 83 8 55 52 2.30 3.00 8 6 4 8 94 92 9 81 - 2.30 4.30 16 8 4 8 95 81

10 67 57 2.29 2.50 15 15 10 11 94 87 M e a n t SD 60 f 13 53 2 9" 2.34 L 0.44 3.26 i- 0.82" 14.5 t 6 12.0 t 7" 5 i 3 8 i- 3* 92 t 4 83 t 7* -~~ ~

PAP = pulmonary artery pressure; RVEDP = right ventricular end-diastolic pressure; LVEDP = left ventricular end- diastolic pressure; Sa02% = arterial oxygen saturation. *P < 0.05 (paired t-test).

Tricuspid regurgitation was documented in the entire group. It was severe in five cases, moderate in two cases, and mild in three cases. Mild pulmonary regurgitation was found in all patients. Two patients presented pericardial

effusion that was mild in one and moderate in the other. Bulging of the interatrial and interventricular septa toward left chambers also was apparent in all cases. LV ejection fraction was normal.

Table I11

Echocardiography Findings Before and After Atrial Septostomy

RVDA RVSA SPAP RATD (mm) RVTD (mm) PATD (mm) (cm2/m) (cm2/m) RVPCA (%) (mmHg)

Patient No. Before After Before After Before After Before After Before After Before After Before After

1 87 58 69 55 37 29 26.5 16.5 20.0 10.6 24 35 101 50 2 57 45 46 38 32 29 25.9 19.1 16.0 13.6 38 29 113 87 3 80 65 55 45 46 36 29.0 16.1 22.6 11.0 22 32 136 85 4 76 66 50 50 33 27 15.6 13.8 19.0 17.8 42 44 87 63 5 92 79 62 56 42 34 45.2 35.6 24.7 20.5 45 43 120 64 6 63 48 51 43 37 35 25.6 24.4 19.5 17.1 24 30 89 65 7 99 82 71 51 47 40 28.8 21.9 20.6 13.8 28 37 95 76 8 54 48 40 33 34 31 18.6 18.6 12.4 11.2 33 40 138 76 9 67 57 50 47 36 31 32.9 28.9 23.7 21.1 28 27 131 90

10 64 61 48 45 35 34 24.8 19.3 13.8 11.7 44 40 120 93 Mean 73.9 60.9 54.2 46.3 37.9 32.6 27.3 21.4 18.2 13.8 32.8 35.7 113 74.9 2 SD 15.3 12.6 10.1 7.2 5.3 3.9 8.0 6.6 5.2 4.4 8.8 6.0 19.1 14.1

*P value 0.001 0.002 0.001 0.002 0.004 0.20 0.001

RATD = right-atrial transversal diameter; RVTD = right ventricular transversal diameter; PATD = pulmonary artery transversal diameter; RVDA = right ventricular diastolic area; RVSA = right ventricular systolic area; RVPCA = right ventricular percent change in area; SPAP = systolic pulmonary artery pressure.

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Echocardiographic Findings After Atrial Septostomy

Transverse right atrial, RV, and PA diameters, as well as RV systolic and diastolic indexed areas and systolic PA pressure, were all decreased significantly after the procedure (P < 0.001) (see Table 111). Likewise, after septostomy there was a tendency to increase the RV mean percent change in area although the changes in this parameter did not achieve a statistically significant difference in the group as a whole. However, as illustrated in Figure 4, the changes in the RV mean percent change in area after septostomy inversely correlated significantly with the preprocedure values of this parameter ( r = -0.77; P < 0.05). Likewise, the changes in RV mean percent change in area inversely correlated with the changes in RV systolic area ( r = -0.75; P < 0.05) but not with the changes in RV diastolic area ( r = -0.33; P = ns.). RVWM after septostomy improved in five patients and it did not change in the other five. From these last five patients, two had normal RVWM before the procedure. Ventric- ular hypokinesis remained mild in two patients and moderate in one of the patients. Changes in RVWM after the procedure correlated with the changes in the RV mean percent change in area ( r = -0.90; P < 0.05). PA systolic pressure decreased significantly (P < 0.001) and pericar-

0 .

dial effusion disappeared after septostomy. RV wall thickness, the degree of tricuspid regurgitation, and the bulging of interatrial and interventricular septa toward left chambers were not modified after the procedure.

Echocard iograp hy Follow - Up

Follow-up from the time of the atrial septostomy to the last outpatient visit was 2 years. Six patients underwent single atrial septosto- mies. The procedure was performed twice in two patients, three times in one patient, and four times in another patient. Average dura- tion of patency of the atrial septostomy was 8 months. Spontaneous closure of the defect was always confirmed by TEE. Also, during follow- up, a right atrial thrombi was detected in one patient after the fourth atrial septostomy. This patient had had a pacemaker placed for control of rhythm abnormalities that occurred after the third septostomy. The patient had signs and symptoms suggestive of transitory cere- bral ischemia all of which subsided spontane- ously.

Discussion

Rationale for Atrial Septostomy in PPH The rationale for the use of atrial septostomy

in the treatment of PPH stands on the fact that

% Change in RVPCA after septostomy . . 50 I I 40 30 20 10

0 . 0

-20 1 r = - 0.77; p < 0.05 . -30 _ _

20 24 28 32 36 40 44 48 Baseline RVPCA %

Figure 4. Modifications of right ventricular mean percent change in area (RVPCA) after septostomy as a function of baseline RVPCA. Improvement i n RVPCA after septostomy is more significant in patients who had more severe depression of systolic function before the procedure (r = -0.77; P < 0.05).

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ESPINOIA-ZAVALETA, ET AL.

deterioration in functional class and death in this condition are associated with obstruction to systemic flow and dilation and failure of the RV.8-12 Theoretically, the presence of an ASD in this setting would allow a right-to-left shunt to increase systemic output, which, despite the fall in systemic arterial SaO,, would increase systemic oxygen transport. At the same time, an atrial septostomy would allow decompression of the RA and RV alleviating RV failure.8-12 Indeed, most prior studies on the effect of atrial septostomy in the setting of PPH have demonstrated the hemodynamic beneficial effect.8-12 This is the first study exploring the effects of BDAS on echocardiography RV structure and function.

Preprocedure Echocardiography Features

As in other echocardiographic studies performed in PPH,18,23v24 most patients in the present study had echocardiographic evidence of marked right atrial and ventricular enlarge- ment. The mean indexed area of the RV was twice that observed in normal control sub- jects.18 On the other hand, RV contractile function, as assessed by the mean percent change in RV area was severely depressed in some but not all patients in the present study, perhaps reflecting the fact that although RV failure was the indication for the procedure in some of the patients, that of recurrent syncope was for the others. Other previously described features of RV pressure and volume overload such as abnormalities of the curvature of the interventricular septum, RV wall hypertrophy, and pericardial effusion also were present in our patients. Likewise, as in other studies on severe PPH,18 correlation between direct measurements of PA systolic pressure and noninvasive estimates, based on continuous-wave Doppler echocardiography measurements of the maximal regurgitant jet velocity, was poor although statistically significant. This discrep- ancy may have been caused by the fact that Doppler studies and PA catheterization were not performed simultaneously and the known spontaneous variability of PA pressure in this group of patients.la

Effects of Atrial Septostomy on RV Structure and Function

Previous studies have shown that atrial septostomy has resulted in improved hemodynamics, exercise capacity, and quality of life in selected patients with severe PPH.8-14 Our echocardiographic data suggest that atrial septostomy also had beneficial effects on right heart structure and function. The significant decrease in right atrial and RV areas after septostomy is a reflection of less right heart dilatation and it is compatible with a decompression effect of the intervention. On the other hand, the effects on RV systolic function, as assessed by the modifications of the RV mean percent change in area and the changes in RVWM, were not the same for all patients. These indices improved only in those with a severely depressed systolic function before the procedure (see Fig. 4).

The easiest way to explain the beneficial effects of atrial septostomy on RV structure and function would be that the simple mechanical effect of decompression after the procedure places the ventricle in a better position on the pressure (or volume) - cardiac output relation- ship (Frank-Starling curve). However, the weak correlation between RV diastolic area changes and the modifications in RV mean percent change in area after the procedure ( r = -0.33; P = n.s.1 suggest that other factor (s) may be involved in the improved systolic function of some of the patients. Relief of wall tension and myocardial ischemia mediated by the decompression itself, although not assessed in the present study, also might have contributed to the improvement in systolic/diastolic ventricular performan~e.2~3~~

Comparison with Other Interventions

Compared with the significant beneficial effects on RV function obtained with other interventions used in the treatment of severe pulmonary hypertension (i.e., thromboendarterectomy for chronic thromboembolic pulmonary hypertension and transplant, calcium channel blockers, and long-term continuous infusion of prostacyclin for PPH),l8,23.24,27 the echocardiographic changes after septostomy appear only



mild or moderate. For instance, although RVDA decreased, it remained well above the normal values after the procedure. This is not a surprising finding. The dramatic echocardiographic improvement or reversal of RV dysfunction observed after pulmonary thromboendarterectomy and transplant are explained easily by the almost complete reduction in pulmonary vascular resistance and normalization of RV afterload exerted by these proce- d~res.23,~7 Likewise, although to a lesser extent, both calcium-channel blockers in a selected group of patients and long-term infusion of prostacyclin produced echocardographic changes that paralleled the significant reduction in pulmonary vascular resistance and RV afterload. 18224

The effects of atrial septostomy in this re- gard are more difficult to define. It is important to stress the fact that pulmonary vascular resistance, one of the major components of RV afterload, is not modified by the procedure; rather, the potential effects of atrial septostomy on RV afterload may be mediated through decompression by the shunting effect and a decrease in RV wall tension. Also, the potential beneficial effects of atrial septostomy on systemic oxygen delivery and on the peripheral oxygen utilization particularly during exercise,11J2 although not fully assessed, also may account for the observed improvement in functional class and exercise capacity of the patients in the presence of the only mild or moderate changes in central hemodynamics and RV function shown after the procedure.

In summary, atrial septostomy in the setting of PPH exerts short-term beneficial effects on RV structure and function that are mediated in part by the decompression effect of the procedure. The precise nature of the pathophysiolog- ical mechanism responsible for the clinical beneficial effects observed after the procedure re- mains to be elucidated.

7.

8.

9.

10.

11.

12.

pertension. Results from a National Prospec- tive Registry. Ann Intern Med 1991;115:343- 349. Sandoval J , Bauerle 0, Palomar A, et al: Sur- vival in primary pulmonary hypertension-val- idation of a prognostic equation. Circulation

Fuster V, Steele PM, Edwards WD, et al: Pri- mary pulmonary hypertension: Natural history and the importance of thrombosis. Circulation

Rich S, Kaufmann E, Levy PS: The effect of high doses of calcium-channel blockers on sur- vival in primary pulmonary hypertension. N Engl J Med 1992;327:76-81. Barst RJ, Rubin LJ, Long WA, et al: A comparison of continuous intravenous epoprostenol (prostacyclin) with conventional therapy for primary pulmonary hypertension. N Engl J Med 1996;334:296-301. Cooper JD, Patterson GA, Trulock EP: Results of single and bilateral lung transplantation in 131 consecutive recipients. J Thorac Cardio- vasc Surg 1994;107:460-471. Rich S , Lam W: Atrial septostomy as palliative therapy for refractory primary pulmonary hypertension. Am J Cardiol 1983;51:1560-1561. Rich S , Dodin E, McLaughlin W: Usefulness of atrial septostomy as a treatment for primary pulmonary hypertension and guidelines for its application. Am J Cardiol 1997;80:369-371. Nihill MR, O’Laughin MP, Mullins CE: Effects of atrial septostomy in patients with terminal cor pulmonale due to pulmonary vascular disease. Cathet Cardiovasc Diagn 1991;24:

Kernstein D, Levy PS, Hsu DT, et al: Blade balloon atrial septostomy in patients with severe primary pulmonary hypertension. Circu- lation 1995;91:2028-2035. Sandoval J, Gaspar J , Pulido T, et al: Graded balloon dilation atrial septostomy in severe primary pulmonary hypertension. A therapeutic alternative for patients nonresponsive to vasodilator treatment. J Am Coll Cardiol 1998;32:

1994;89:1733-1744.

1984;70:580-587.

166-172.

297-304. 13. Hausknecht M, Sims RE, Nihill MR, et al: Suc-

cessful palliative of primary pulmonary hypertension by atrial septostomy. Am J Cardiol

Cardiovasc Dis 1988;31:205-238. 14. Rothman A, Beltran D, Kriett JM, et al: D’Alonzo GE, Barst RJ, Ayres SM, et al: Sur- Graded balloon dilation atrial septostomy as a viva1 in patients with primary pulmonary hy- bridge to transplantation in primary pulmo-

References

1. Rich S: Primary pulmonary hypertension. Prog 1990;65:1045-1046.

2.

Vol. 16, No. 7, Part 1, 1999 ECHOCARDIOGWHY: A Jrnl. of CV Ultrasound & Allied Tech. 633


15.

16.

17.

18.

19.

20.

21.

nary hypertension. Am Heart J 1993;125:1763- 1766. Sandoval J, Pulido T, Suarez J , et al: Adeno- sine as a predictor of the hemodynamic response to nifedipine in primary pulmonary hypertension. J Respir Crit Care Med 1997; 155(suppl):A443. Abstract. Guyatt GH, Sullivan MJ, Thompson PJ, e t al: The 6-minute walk: A new measure of exercise capacity in patients with chronic heart failure. Can Med Assoc J 19985;132:919-923. Kaul S, Tei C, Hopkins JM, et al: Assessment of right ventricular function using two-dimensional echocardiography. Am Heart J 1984;107:

Hinderliter AL, Willis W, Barst RJ, et al: Ef- fects of long-term infusion of prostacyclin (Epoprostenol) on echocardiographic measures of right ventricular structure and function in primary pulmonary hypertension. Circulation

Espinola-Zavaleta N, Vargas Barron J, Romero Cardenas A, et al: Multiplane transesophageal echocardiography with dobutamine in patients with biventricular inferior myocardial infarc- tion. Echocardiography 1998;15:181-189. Hatle L, Angelsen B: Doppler ultrasound in cardiology: Physical principles and clinical application. Lea and Febiger, Philadelphia, Pa,

Berger M, Haimowitz A, Van Tosh A, et al: Quantitative assessment of pulmonary hypertension in patients with tricuspid regurgitation

526-531.

1997;95:1479-1486.

1982~113-116.

22.

23.

24.

25.

26.

27.

using continuous wave Doppler ultrasound. J Am Coll Cardiol 1985;6:359-365. Chopra HK, Nanda NC, Fan P, et al: Can two- dimensional echocardiography and Doppler color flow mapping identify the need for tricuspid valve repair. J Am Coll Cardiol 1989;14: 1266-1274. Ritchie M, Waggoner A, Davila-Roman VG, et al: Echocardiographic characterization of the improvement in right ventricular function in patients with severe pulmonary hypertension after single-lung transplantation. J Am Coll Cardiol 1993;22:1170-1174. Rich S , Brundage BH: High-dose calcium channel-blocking therapy for primary pulmonary hypertension: Evidence for long-term reduction in primary arterial pressure and regression of right ventricular hypertrophy. Circulation

Vlahakes GJ, Turley K, Hoffman JIE: The pathophysiology of failure in acute right ventricular hypertension: Hemodynamic and bio- chemical correlations. Circulation 1981;63:87- 95. Widemann HP, Matthay R A The management of acute and chronic cor pulmonale. In: Scharf SM, Cassidy SS, eds. Heart and Lung Interac- tions in Health and Disease, Chapter 27. Mar- cel Dekker, Inc., New York NY, 1989:915-981. Dittrich HC, Nicod PH, Chow LC, et al: Early changes of right heart geometry after pulmonary thromboendarterectomy. J Am Colt Car- diol 1998;11:937-943.

1987;76:135-141.


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