Catheterization and Cardiovascular Diagnosis 3: 11-19 (1977)
PULMONARY ARTERY WEDGE PRESSURES IN CONGENITAL HEART DISEASE William H. Neches, M.D., Sang C. Park, M.D., Cora C. Lenox, M.D., J. R. Zuberbuhler, M.D., Charles E. Mullins, M.D., and Dan G.McNamara, M.D. The bilateral measurement of pulmonary artery wedge pressure i s essential in the cardiac catheterization evaluation of all patients with pulmonary artery hypertension. Five cases of pulmonary venous obstruction are presented, 4 of whom had additional intracardiac defects. The pulmonary artery hypertension in these 4 patients was initially attributed to the associated cardiac anomalies and because the left atrium had been entered directly with the catheter in each case, pulmonary artery wedge to the left atrium pressuregradients were initially either not obtained or werediscounted as beiny artificial. Pulmonary venous obstruction was recognized in all Bcases on the basis of an elevated pulmonary artery wedge pressure, and the anatomic site of the obstruction was successfully documented. Unless bilateral pulmonary artery wedge pressures are measured in all patients with pulmonary artery hypertension regardless of the presence of additional cardiac anomalies, a surgically correctable cause of pulmonary hypertension may be overlooked.
INTRODUCTION
The pulmonary artery wedge (PAW) pressure affords a reliable estimate of pressure in the pulmonary venous circulation during the evaluation of patients with pulmonary artery hypertension (1-5). In many cases, either because of technical difficulties or because the left atrial pressure has been measured directly, an accurate PAW pressure is not obtained. As a result, a surgically correctable cause of pulmonary artery hypertension may thus be overlooked, especially if the patient has another cardiac defect. This report will describe 5 patients with congenital heart disease in whom the correct diagnosis was established because of an elevated PAW pressure. From the Children’s Hospital of Pittsburgh and the University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, and the Texas Children’s Hospital and Baylor College of Medicine, Houston, Texas
Supported in part by a grant from the Beaver County (Pennsylvania) Heart Association and by USPSH Grant #HE 5754 (Houston). Reprint requests to: William H . Neches, M.D., Cardiology Division, Children’s Hospital of Pitt5burgh. 125 DeSoto Street. Pittsburgh, PA 15213 Received May 23, 1976; revision accepted August 14, 1976
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0 1 9 7 7 Alan R. Lin, Inc., 150 Fifth Avenue, New Vork, N V 10011
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TABLE I. Cardiac Catheterization Data: Pulmonary Vein Stenosis - Cases I and II
Case I Age 1 1 mo.
Case 11 Age 10 10/12 yr.
Catheter position
Pressure (mm. Hg.)
02 sat.
svc
m=2 6212 62/27(40) m = 32 m = 22 m = 44 m = 44 m = 32 m = 35 m=5
59 63 64 64 99 -
RA RV PA PAW-R PAW-L PV-RU PV-R L PV-LU PV-LL LA LV A 0 or 1.4
llO/ll 110/70(95)
(%)
-
97 98 98
Pressure (mm. Hg.)
sat. (%)
02
-
66 71 66 68
m=2 12515 115/60(75) m = 18 m = 18 m = 40 m = 40 m = 28
-
98 96
-
-
m=3 12014 140/80(95)
94 95 95 ~~
Abbreviations: A 0 = Aorta LA = Left atrium LV = Left ventricle PA = Pulmonary artery PAW = Pulmonary artery wedge
PV = Pulmonary vein LU = Left upper LL = Left lower RL = Right lower R U = Right upper
RA = Right atrium RV = Right ventricle SVC = Superior vena cava
CASE REPORTS Case I
This patient was first seen at Children’s Hospital of Pittsburgh at age 3 months because of congestive heart failure. Physical examination suggested the presence of coarctation of the aorta and an atrial septa1 defect. Chest roentgenogram showed moderate cardiomegaly with increased pulmonary vascular markings, and right ventricular hypertrophy (RVH) was found on electrocardiogram. Cardiac catheterization showed a left-to-right shunt at atrial level with a pulmonary to systemic flow ratio of 2.5: 1 and moderate pulmonary artery hypertension. Left atrial pressure was normal and the PAW pressure was not measured. A coarctation of the aorta was also demonstrated. A second cardiac catheterization at 1 1 months of age again demonstrated moderate pulmonary artery hypertension but no left-to-right shunt was found (Table I). A significantly elevated (PAW) pressure was found bilaterally (32 mm.Hg. mean pressure on the right and 22mm.Hg. on the left). The catheter could be passed across an interatrial communication, and each of the 4 pulmonary veins was selectively catheterized. The pressure in the pulmonary veins was extremely high, and an abrupt change in pressure was noted on pullback tracings from the pulmonary veins to the left atrium. Selective cineangiography in each pulmonary vein demonstrated marked narrowing of the venoatrial junctions (Fig. 1A).
Pulmonary Artery Wedge Pressures
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Fig. 1. Selective pulmonary vein angiograms in Cases I (A) and II (B), demonstrating stenosis at the venoatrial junctions (arrows). LL = left lower pulmonary vein; LU = Left upper pulmonary vein; RL = Right lower pulmonary vein; RU = Right upper pulmonary vein.
The right-sided pulmonary venous obstruction appeared to be more severe, and a decision was made to initially correct only the stenosis on that side. At operation a pericardial patch angioplasty was performed on the right pulmonary veins. The patient expired a few hr postoperatively, and postmortem examination demonstrated thrombosis at the operative site in the 2 right pulmonary veins. There was marked narrowing of the left pulmonary veins at the venoatrial junctions, as well as a mild coarctation of the aorta.
Case II This patient had a history of a heart murmur since early infancy. Congestive heart failure was first noted at 4 months of age. At 10 months of age, cardiac catheterization was performed at Children’s Hospital of Pittsburgh, and demonstrated a ventricular septal defect and pulmonary artery hypertension with equal pulmonary artery and systemic pressures. The patient’s ventricular septal defect was closed surgically at 21 months of age. Postoperatively the clinical findings of pulmonary hypertension did not subside, and cardiomegaly with increased pulmonary vascularity persisted on chest roentgenogram. Cardiac catheterization was performed at 3 years and 9 months of age, and again showed pulmonary artery hypertension. A mean PAW pressure of 18 mm.Hg. was obtained but was thought to be technically inaccurate and was disregarded. No evidence of a residual ventricular septal defect was found. Cardiac catheterization was again performed at 10 10/12 years of age. Marked pulmonary artery hypertension as well as elevation of the PAW pressure bilaterally (mean = 18 mm.Hg.) were found (Table I). The catheter was passed into all but the left lower pulmonary vein. Pressures were elevated in each pulmonary vein. and an abrupt change in pressure was noted at the venoatrial junction. Selective pulmonary venous angiography showed marked narrowing of the venoatrial junctions (Fig. 1B).
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Neches et al.
Using cardiopulmonary by-pass, a pulmonary vein angioplasty was performed. An intraluminal membranous diaphragm was found to be the cause of the obstruction in the right pulmonary veins. In the left pulmonary veins the lumen was narrowed by an irregular thickening of the intima at the venoatrial junction. No evidence of extrinsic pulmonary vein compression could be found. The patient initially did well, but 4 months postoperatively he again developed marked exercise intolerance, and clinical findings suggested increasing pulmonary artery hypertension. Cardiac catheterization showed restenosis of the pulmonary veins, more severe on the left than on the right. The patient expired shortly after operation for relief of the left-sided stenosis. At autopsy the left pulmonary veins were widely patent but the lumina of the right pulmonary veins were markedly narrowed at the site of the previous repair. Case 111
A 7 %-year-old caucasion male was referred to Children's Hospital of Pittsburgh for evaluation of a heart murmur. There was a 2-year history of exertional dyspnea and easy fatigability. On physical examination a slight bulge of the precordium and a left parasternal heave were noted. The 2nd heart sound was loud and single. A Grade I/VI continuous murmur with diastolic accentuation was heard maximally at the upper left sternal border. A Grade I/VI blowing pansystolic murmur was also present at the apex. The electrocardiogram showed RVH, and the chest roentgenogram demonstrated a normal size heart, very large hilar pulmonary arteries, and normal pulmonary vascularity. At cardiac catheterization, pulmonary artery hypertension with equal pulmonary artery and systemic pressures was found (Table 11). During the initial phase of the catheterization it was very difficult to obtain an adequate PAW pressure. Selective right ventricular cineangiocardiography showed a large right ventricle and huge pulmonary arteries. On the levophase the left atrium was found to be enlarged and there was no evidence of pulmonary venous obstruction, mitral valve abnormality, or left-to-right shunting (Fig. 2A). Further attempts to obtain PAW pressure were successful, and the mean pressures were found to be about 30 mm.Hg. Retrograde arterial catheterization was then performed and the catheter could be advanced from the left ventricle across the mitral valve and into the left atrium where the pressures were normal. A selective cineangiocardiogram (Fig. 2B) showed a small distal left atrial chamber to which was attached the left atrial appendage. Surgical correction was performed, and the patient made an uneventful recovery. Cardiac catheterization 6 months postoperatively revealed normal hemodynamics. The PAW pressure was normal as well (25110 m=15). Case IV
This I-year-old boy was referred to Texas Children's Hospital because of congestive heart failure. A heart murmur had been heard for the first time at 7 months of age. On physical examination, a Grade III/VI systolic ejection murmur was heard loudest at the upper left sternal border. A Grade I I W I middiastolic murmur was also present at the lower left sternal border. Chest roentgenogram showed moderate cardiomegdy, a prominent main pulmonary artery, and increased pulmonary vascular markings. On electrocardiogram, RVH was found.
15
Pulmonary A r t e r y Wedge Pressures T A B L E II. Cardiac Catheterization Data: Cor T r i a t r i a t u m
- Cases Ill, IV, and V ~
Case I11 Age 7 112 yrs Catheter position
svc RA RV PA PAW-R PAW-L PV-RU PV-RL PV-LU LV-LL LA LV A 0 or FA
Pressure (mm. Hg.) -
105/5 105/60(80) m = 31 m = 30 -
02sat. (%)
70 68 66 68 100
Age 1 yr Pressure (mm. Hg.) m=4 4515 35/ 1 5 (2 0) m = 15 m = 12
Case 1V Age 14/12 yrs
0 2 sat.
(%)
54 74 73 75
.-
m=2 100/3 100/65(85)
m = 12 m = 14 m = 6** 8017
100
90/50(70)
Abbreviations: A 0 = Aorta LA = Left atrium LV = Left ventricle PA = Pulmonary artery PAW = Pulmonary artery wedge
92 90 93 93 93
Pressure (mm.Hg.)
m=3 70/7 70/30(50) m = 25 m = 10
02
sat.
(%)
64 78 78 71 -
-
-
m = 10
90
~
Case V Age 3 yrs Pressure (mm.Hg.)
(%)
m=6 8517 75/30(50) m=23
71 82 86 88 -
-
95 96 88 91
m = 24* m = 26*
-
-
-
n, = 7** 80/7
95 96
m = 7** 95/8
PV = Pulmonary vein LU = Left upper LL = Left lower RL = Right lower RU = Right upper
0 2 sat.
-
RA = Right atrium RV = Right ventricle SVC = Superior vena cava * Proximal LA chamber **Distal LA chamber
Fig. 2. Case 111. Cineangiocardiograms-right anterior oblique view. A. Levophase following right ventricular injection of contrast material.
No conclusions can be made about pulmonary venous or mitral valve abnormalities. B. Selective injection in the distal left atrial chamber with a retrograde arterial catheter. The membrane of the cor triatriatum (arrows) separatesthe proximal pulmonaryvenous chamber, which is not opacified, from the distal left atrial chamber.
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Neches et al.
Fig. 3. Case IV. Levophasefollowing selective pulmonaryartery injection (anteroposteriorview). A. Right pulmonaryartery injection: normal pulmonaryvenous return is seen. There is a suggestion of a filling defect in the left atrium (arrow), which represents the membrane of the cor triatriatum. B. Left pulmonaryartery injection: pulmonaryvenous return is to the coronary sinus (CS), which drains into the right atrium.
Cardiac catheterization revealed partial anomalous pulmonary venous drainage of the left pulmonary veins to the coronary sinus. The right pulmonary veins drained normally to the left atrium. The interventricular septum was intact and a patent foramen ovale was present. There was no gradient between the left PAW and the left pulmonary vein pressure (Table 11). Although there was a 9 mm.Hg. mean gradient between the right PAW and left atrium, these pressures were obtained at different times during the catheterization, and the differences were discounted as not being real. Over the ensuing4 months, the patient continued to have congestive heart failure despite adequate therapy with digitalis and diuretics. A repeat cardiac catheterization showed severe pulmonary artery hypertension (Table 11). There was no gradient between the left PAW and the left pulmonary veins. The right PAW pressure was found to be 25 mm.Hg., about 3 4 times the pressure found in the left atrium. On angiocardiography partial anomalous pulmonary venous drainage of the left lung to the coronary sinus was again demonstrated (Fig. 3B). The contrast material was seen to clear quite sluggishly from the pulmonary venous circulation on the right side, and there was a suggestion of the presence of an obstructing membrane in the left atrium (Fig. 3A). At operation an obstructing membrane was found in the left atrium and was removed. The coronary sinus was opened and included in the left atrium, thus allowing drainage of the left pulmonary veins into the systemic circulation. The patient’s postoperative course was uneventful, and he has had a normal growth and development since then.
Pulmonary Artery Wedge Pressures
17
Case V A 3-year-old Caucasian female was referred to Texas Children's Hospital for cardiac surgery. Cardiac catheterization had been performed at 2 years of age at another institution, and both atrial and ventricular septal defects had been found. Chest roentgenogram demonstrated cardiomegaly, right atrial enlargement, and increased pulmonary vascularity. The electrocardiogram demonstrated left axis deviation, first degree atrioventricular block, right atrial enlargement, and biventricular hypertrophy. These findings suggested a diagnosis of complete endocardial cushion defect. Cardiac catheterization was performed and confirmed the clinical impression (Table 11). There was a left-to-right shunt at atrial as well as ventricular level. The pulmonary to systemic flow ratio was 3: I , and pulmonary artery hypertension at almost systemic level was found. The right PAW pressure was elevated (m=23 mm.Hg.), and a marked gradient was found between the pulmonary veins and left atrium. Selective angiocardiography demonstrated cor triatriatum, in addition to the complete endocardial cushion defect. At age 4 '/z years corrective surgery was performed, and at operation the cardiac catheterization diagnosis was confirmed. The patient has done well postoperatively, and is to have a follow-up cardiac catheterization next year.
DISCUSSION
Although obstruction to pulmonary venous return is an uncommon cause of pulmonary artery hypertension, it is a form which is amenable to surgical correction. In those patients with pulmonary artery hypertension in whom no cardiac defects have been found, a concerted attempt is usually made to obtain PAW pressures to eliminate the possibility of pulmonary venous obstruction being present. However, in many cases, either because of technical difficulties or because the left atrial pressure has been measured directly, an accurate PAW pressure is not obtained. This is especially the case in patients who have other congenital cardiac defects that could be the cause of the pulmonary artery hypertension. The first 2 cases were found to have pulmonary vein stenosis in addition to other cardiac abnormalities, and have been previously reported in detail (6). One patient also had coarctation of the aorta and an atrial septal defect: the other had a large ventricular septal defect. In each instance a bilateral PAW pressure was obtained at a follow-up cardiac catheterization and this led to the diagnosis of pulmonary vein stenosis. Since there are no suggestive auscultatory findings of pulmonary vein stenosis, and frequently no suggestive radiographic findings as well, the diagnosis depends upon the demonstration of agradient between the PAW and the left atrium, with subsequent visualization by selective pulmonary vein angiography (6). In addition, since pulmonary artery hypertension can develop in patients with unilateral pulmonary vein stenosis (7), bilateral PAW pressure measurement is essential. In Case 111, an elevated PAW pressure and pulmonary artery hypertension led to the diagnosis of cor triatriatum. Cases IV and V serve to again stress the importance of bilateral PAW pressure measurement in all patients who have pulmonary hypertension, even if cardiac defects are present that in themselves are sufficient to be the cause of the hypertension.
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Neches et al.
There are additional congenital or acquired cardiac abnormalities, such as mitral stenosis and left ventricular dysfunction, that manifest elevation of the pulmonary venous and PAW pressures. Pulmonary vein stenosis and cor triatriatum are the only cases included in this discussion because these lesions are usually silent by auscultation and are more difficult to document by intracardiac pressure determinations and ci neangiocardiograph y . Pulmonary artery angiography may sometimes confirm the diagnosis of various types of pulmonary venous obstruction. In some instances, such as occurred in the cases presented here, even selective pulmonary artery angiography may not adequately demonstrate the lesion. This is especially true if PAW pressures are not measured, and, thus, the presence of pulmonary venous obstruction is not even suspected. In 4 of the 5 cases presented (I, 11, IV, V) the left atrium had been entered with the catheter and the pressures there were found to be normal. Had bilateral PAW pressures not been obtained, pulmonary venous obstruction might not have even been considered as a cause of the pulmonary hypertension in these patients. An accurate PAW pressure is readily obtained in most patients using an end-hole catheter. Although asking the patient to take a deep breath while the catheter is being advanced into the distal pulmonary artery is helpful in adults, this maneuver is of little use in children due to their lack of cooperation. I n many cases, when difficulties in passage of the catheter into the PAW position are encountered, 1) the use of another more rigid catheter, 2 ) the use of a guide wire to stiffen the catheter, or 3) even the use of a small-diameter catheter to enable passage into the smaller vessels, may be helpful. Flushing the catheter immediately prior to and after the catheter is advanced into the PAW position is also helpful in obtaining a good pressure curve. Once the catheter is properly positioned the criteria for an accurate PAW pressure are: 1) A pressure wave-form similar to a left atrial pressure curve. 2) Withdrawal of a fully saturated blood sample. 3) On withdrawal, the catheter, which is usually tightly held in the PAW position, should "pop" back into the branch pulmonary artery. This should be accompanied by an abrupt change in the pressure contour. With the development of the flow-directed balloon-tipped catheter, good quality PAW pressure tracings can now be quickly and easily obtained in most patients, even under difficult circumstances (8-9). Thus, especially in view of the findings presented in our patients, the measurement of PAW pressures bilaterally is an essential part of the evaluation of all patients with pulmonary artery hypertension.
REFERENCES I . Walston A and Kendall ME: Comparison of pulmonary wedge and left atrial pressure in man. Am Heart J 86:159-164. 1973 2. Fitzpatrick GF, Hampson LG, Burgess JH: Bedside determination of left atrial pressure. Can Med ASSOCJ 106:1293-1298. 1972 3. Hellems HK, Haynes FW, and Dexter L: Pulmonary "capillary" pressure in man. J Appl Physiol 2~24-29, 1949 4. Connolly DC. Kirklin JW and Wood EH: The relationship between pulmonary artery wedge pressure and left atrial pressure in man. Circ. Res 2:434-440, 1954 5 . Samet P, Litwak RS, Bernstein WH, Fierer EM and Silverman LM: Clinical and physiologic relationships in mitral valve disease. Circulation 19:517-530. 1959
Pulmonary Artery Wedge Pressures
19
6. Park. SC, Neches WH, Lenox CC, Zuberbuhler JR, Siewers RD and Bahnson HT: Diagnosis and surgical treatment ofbilateral pulmonary vein stenosis. J Thoracic Cardiovasc Surg. 67:755-76 I , 1974 7 . Ferencz C, Dammann J F Jr: Significance of the pulmonary vascular bed in congenital heart disease: V. Lesions of the left side of the heart causing obstruction of the pulmonary venous return. Circulation 16: 1046-1056, 1957. 8. Swan HJC, Ganz W. Forrester J , Marcus H , Diamond G and Chonette D: Catheterization ofthe heart in man with use of a flow-directed balloon-tipped catheter. New Engl. 1 Med 283:447-451, 1970 9. Stanger P. Heyrnann MA, Hoffman JIE, Rudolph AM: Use of the Swan Ganz catheter in cardiac catheterization of infants and children. Am Heart J 83:74%754. 1972
PULMONARY ARTERY WEDGE PRESSURES IN CONGENITAL HEART DISEASE William H. Neches, M.D., Sang C. Park, M.D., Cora C. Lenox, M.D., J. R. Zuberbuhler, M.D., Charles E. Mullins, M.D., and Dan G.McNamara, M.D. The bilateral measurement of pulmonary artery wedge pressure i s essential in the cardiac catheterization evaluation of all patients with pulmonary artery hypertension. Five cases of pulmonary venous obstruction are presented, 4 of whom had additional intracardiac defects. The pulmonary artery hypertension in these 4 patients was initially attributed to the associated cardiac anomalies and because the left atrium had been entered directly with the catheter in each case, pulmonary artery wedge to the left atrium pressuregradients were initially either not obtained or werediscounted as beiny artificial. Pulmonary venous obstruction was recognized in all Bcases on the basis of an elevated pulmonary artery wedge pressure, and the anatomic site of the obstruction was successfully documented. Unless bilateral pulmonary artery wedge pressures are measured in all patients with pulmonary artery hypertension regardless of the presence of additional cardiac anomalies, a surgically correctable cause of pulmonary hypertension may be overlooked.
INTRODUCTION
The pulmonary artery wedge (PAW) pressure affords a reliable estimate of pressure in the pulmonary venous circulation during the evaluation of patients with pulmonary artery hypertension (1-5). In many cases, either because of technical difficulties or because the left atrial pressure has been measured directly, an accurate PAW pressure is not obtained. As a result, a surgically correctable cause of pulmonary artery hypertension may thus be overlooked, especially if the patient has another cardiac defect. This report will describe 5 patients with congenital heart disease in whom the correct diagnosis was established because of an elevated PAW pressure. From the Children’s Hospital of Pittsburgh and the University of Pittsburgh School of Medicine, Pittsburgh, Pennsylvania, and the Texas Children’s Hospital and Baylor College of Medicine, Houston, Texas
Supported in part by a grant from the Beaver County (Pennsylvania) Heart Association and by USPSH Grant #HE 5754 (Houston). Reprint requests to: William H . Neches, M.D., Cardiology Division, Children’s Hospital of Pitt5burgh. 125 DeSoto Street. Pittsburgh, PA 15213 Received May 23, 1976; revision accepted August 14, 1976
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0 1 9 7 7 Alan R. Lin, Inc., 150 Fifth Avenue, New Vork, N V 10011
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TABLE I. Cardiac Catheterization Data: Pulmonary Vein Stenosis - Cases I and II
Case I Age 1 1 mo.
Case 11 Age 10 10/12 yr.
Catheter position
Pressure (mm. Hg.)
02 sat.
svc
m=2 6212 62/27(40) m = 32 m = 22 m = 44 m = 44 m = 32 m = 35 m=5
59 63 64 64 99 -
RA RV PA PAW-R PAW-L PV-RU PV-R L PV-LU PV-LL LA LV A 0 or 1.4
llO/ll 110/70(95)
(%)
-
97 98 98
Pressure (mm. Hg.)
sat. (%)
02
-
66 71 66 68
m=2 12515 115/60(75) m = 18 m = 18 m = 40 m = 40 m = 28
-
98 96
-
-
m=3 12014 140/80(95)
94 95 95 ~~
Abbreviations: A 0 = Aorta LA = Left atrium LV = Left ventricle PA = Pulmonary artery PAW = Pulmonary artery wedge
PV = Pulmonary vein LU = Left upper LL = Left lower RL = Right lower R U = Right upper
RA = Right atrium RV = Right ventricle SVC = Superior vena cava
CASE REPORTS Case I
This patient was first seen at Children’s Hospital of Pittsburgh at age 3 months because of congestive heart failure. Physical examination suggested the presence of coarctation of the aorta and an atrial septa1 defect. Chest roentgenogram showed moderate cardiomegaly with increased pulmonary vascular markings, and right ventricular hypertrophy (RVH) was found on electrocardiogram. Cardiac catheterization showed a left-to-right shunt at atrial level with a pulmonary to systemic flow ratio of 2.5: 1 and moderate pulmonary artery hypertension. Left atrial pressure was normal and the PAW pressure was not measured. A coarctation of the aorta was also demonstrated. A second cardiac catheterization at 1 1 months of age again demonstrated moderate pulmonary artery hypertension but no left-to-right shunt was found (Table I). A significantly elevated (PAW) pressure was found bilaterally (32 mm.Hg. mean pressure on the right and 22mm.Hg. on the left). The catheter could be passed across an interatrial communication, and each of the 4 pulmonary veins was selectively catheterized. The pressure in the pulmonary veins was extremely high, and an abrupt change in pressure was noted on pullback tracings from the pulmonary veins to the left atrium. Selective cineangiography in each pulmonary vein demonstrated marked narrowing of the venoatrial junctions (Fig. 1A).
Pulmonary Artery Wedge Pressures
13
Fig. 1. Selective pulmonary vein angiograms in Cases I (A) and II (B), demonstrating stenosis at the venoatrial junctions (arrows). LL = left lower pulmonary vein; LU = Left upper pulmonary vein; RL = Right lower pulmonary vein; RU = Right upper pulmonary vein.
The right-sided pulmonary venous obstruction appeared to be more severe, and a decision was made to initially correct only the stenosis on that side. At operation a pericardial patch angioplasty was performed on the right pulmonary veins. The patient expired a few hr postoperatively, and postmortem examination demonstrated thrombosis at the operative site in the 2 right pulmonary veins. There was marked narrowing of the left pulmonary veins at the venoatrial junctions, as well as a mild coarctation of the aorta.
Case II This patient had a history of a heart murmur since early infancy. Congestive heart failure was first noted at 4 months of age. At 10 months of age, cardiac catheterization was performed at Children’s Hospital of Pittsburgh, and demonstrated a ventricular septal defect and pulmonary artery hypertension with equal pulmonary artery and systemic pressures. The patient’s ventricular septal defect was closed surgically at 21 months of age. Postoperatively the clinical findings of pulmonary hypertension did not subside, and cardiomegaly with increased pulmonary vascularity persisted on chest roentgenogram. Cardiac catheterization was performed at 3 years and 9 months of age, and again showed pulmonary artery hypertension. A mean PAW pressure of 18 mm.Hg. was obtained but was thought to be technically inaccurate and was disregarded. No evidence of a residual ventricular septal defect was found. Cardiac catheterization was again performed at 10 10/12 years of age. Marked pulmonary artery hypertension as well as elevation of the PAW pressure bilaterally (mean = 18 mm.Hg.) were found (Table I). The catheter was passed into all but the left lower pulmonary vein. Pressures were elevated in each pulmonary vein. and an abrupt change in pressure was noted at the venoatrial junction. Selective pulmonary venous angiography showed marked narrowing of the venoatrial junctions (Fig. 1B).
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Using cardiopulmonary by-pass, a pulmonary vein angioplasty was performed. An intraluminal membranous diaphragm was found to be the cause of the obstruction in the right pulmonary veins. In the left pulmonary veins the lumen was narrowed by an irregular thickening of the intima at the venoatrial junction. No evidence of extrinsic pulmonary vein compression could be found. The patient initially did well, but 4 months postoperatively he again developed marked exercise intolerance, and clinical findings suggested increasing pulmonary artery hypertension. Cardiac catheterization showed restenosis of the pulmonary veins, more severe on the left than on the right. The patient expired shortly after operation for relief of the left-sided stenosis. At autopsy the left pulmonary veins were widely patent but the lumina of the right pulmonary veins were markedly narrowed at the site of the previous repair. Case 111
A 7 %-year-old caucasion male was referred to Children's Hospital of Pittsburgh for evaluation of a heart murmur. There was a 2-year history of exertional dyspnea and easy fatigability. On physical examination a slight bulge of the precordium and a left parasternal heave were noted. The 2nd heart sound was loud and single. A Grade I/VI continuous murmur with diastolic accentuation was heard maximally at the upper left sternal border. A Grade I/VI blowing pansystolic murmur was also present at the apex. The electrocardiogram showed RVH, and the chest roentgenogram demonstrated a normal size heart, very large hilar pulmonary arteries, and normal pulmonary vascularity. At cardiac catheterization, pulmonary artery hypertension with equal pulmonary artery and systemic pressures was found (Table 11). During the initial phase of the catheterization it was very difficult to obtain an adequate PAW pressure. Selective right ventricular cineangiocardiography showed a large right ventricle and huge pulmonary arteries. On the levophase the left atrium was found to be enlarged and there was no evidence of pulmonary venous obstruction, mitral valve abnormality, or left-to-right shunting (Fig. 2A). Further attempts to obtain PAW pressure were successful, and the mean pressures were found to be about 30 mm.Hg. Retrograde arterial catheterization was then performed and the catheter could be advanced from the left ventricle across the mitral valve and into the left atrium where the pressures were normal. A selective cineangiocardiogram (Fig. 2B) showed a small distal left atrial chamber to which was attached the left atrial appendage. Surgical correction was performed, and the patient made an uneventful recovery. Cardiac catheterization 6 months postoperatively revealed normal hemodynamics. The PAW pressure was normal as well (25110 m=15). Case IV
This I-year-old boy was referred to Texas Children's Hospital because of congestive heart failure. A heart murmur had been heard for the first time at 7 months of age. On physical examination, a Grade III/VI systolic ejection murmur was heard loudest at the upper left sternal border. A Grade I I W I middiastolic murmur was also present at the lower left sternal border. Chest roentgenogram showed moderate cardiomegdy, a prominent main pulmonary artery, and increased pulmonary vascular markings. On electrocardiogram, RVH was found.
15
Pulmonary A r t e r y Wedge Pressures T A B L E II. Cardiac Catheterization Data: Cor T r i a t r i a t u m
- Cases Ill, IV, and V ~
Case I11 Age 7 112 yrs Catheter position
svc RA RV PA PAW-R PAW-L PV-RU PV-RL PV-LU LV-LL LA LV A 0 or FA
Pressure (mm. Hg.) -
105/5 105/60(80) m = 31 m = 30 -
02sat. (%)
70 68 66 68 100
Age 1 yr Pressure (mm. Hg.) m=4 4515 35/ 1 5 (2 0) m = 15 m = 12
Case 1V Age 14/12 yrs
0 2 sat.
(%)
54 74 73 75
.-
m=2 100/3 100/65(85)
m = 12 m = 14 m = 6** 8017
100
90/50(70)
Abbreviations: A 0 = Aorta LA = Left atrium LV = Left ventricle PA = Pulmonary artery PAW = Pulmonary artery wedge
92 90 93 93 93
Pressure (mm.Hg.)
m=3 70/7 70/30(50) m = 25 m = 10
02
sat.
(%)
64 78 78 71 -
-
-
m = 10
90
~
Case V Age 3 yrs Pressure (mm.Hg.)
(%)
m=6 8517 75/30(50) m=23
71 82 86 88 -
-
95 96 88 91
m = 24* m = 26*
-
-
-
n, = 7** 80/7
95 96
m = 7** 95/8
PV = Pulmonary vein LU = Left upper LL = Left lower RL = Right lower RU = Right upper
0 2 sat.
-
RA = Right atrium RV = Right ventricle SVC = Superior vena cava * Proximal LA chamber **Distal LA chamber
Fig. 2. Case 111. Cineangiocardiograms-right anterior oblique view. A. Levophase following right ventricular injection of contrast material.
No conclusions can be made about pulmonary venous or mitral valve abnormalities. B. Selective injection in the distal left atrial chamber with a retrograde arterial catheter. The membrane of the cor triatriatum (arrows) separatesthe proximal pulmonaryvenous chamber, which is not opacified, from the distal left atrial chamber.
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Fig. 3. Case IV. Levophasefollowing selective pulmonaryartery injection (anteroposteriorview). A. Right pulmonaryartery injection: normal pulmonaryvenous return is seen. There is a suggestion of a filling defect in the left atrium (arrow), which represents the membrane of the cor triatriatum. B. Left pulmonaryartery injection: pulmonaryvenous return is to the coronary sinus (CS), which drains into the right atrium.
Cardiac catheterization revealed partial anomalous pulmonary venous drainage of the left pulmonary veins to the coronary sinus. The right pulmonary veins drained normally to the left atrium. The interventricular septum was intact and a patent foramen ovale was present. There was no gradient between the left PAW and the left pulmonary vein pressure (Table 11). Although there was a 9 mm.Hg. mean gradient between the right PAW and left atrium, these pressures were obtained at different times during the catheterization, and the differences were discounted as not being real. Over the ensuing4 months, the patient continued to have congestive heart failure despite adequate therapy with digitalis and diuretics. A repeat cardiac catheterization showed severe pulmonary artery hypertension (Table 11). There was no gradient between the left PAW and the left pulmonary veins. The right PAW pressure was found to be 25 mm.Hg., about 3 4 times the pressure found in the left atrium. On angiocardiography partial anomalous pulmonary venous drainage of the left lung to the coronary sinus was again demonstrated (Fig. 3B). The contrast material was seen to clear quite sluggishly from the pulmonary venous circulation on the right side, and there was a suggestion of the presence of an obstructing membrane in the left atrium (Fig. 3A). At operation an obstructing membrane was found in the left atrium and was removed. The coronary sinus was opened and included in the left atrium, thus allowing drainage of the left pulmonary veins into the systemic circulation. The patient’s postoperative course was uneventful, and he has had a normal growth and development since then.
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Case V A 3-year-old Caucasian female was referred to Texas Children's Hospital for cardiac surgery. Cardiac catheterization had been performed at 2 years of age at another institution, and both atrial and ventricular septal defects had been found. Chest roentgenogram demonstrated cardiomegaly, right atrial enlargement, and increased pulmonary vascularity. The electrocardiogram demonstrated left axis deviation, first degree atrioventricular block, right atrial enlargement, and biventricular hypertrophy. These findings suggested a diagnosis of complete endocardial cushion defect. Cardiac catheterization was performed and confirmed the clinical impression (Table 11). There was a left-to-right shunt at atrial as well as ventricular level. The pulmonary to systemic flow ratio was 3: I , and pulmonary artery hypertension at almost systemic level was found. The right PAW pressure was elevated (m=23 mm.Hg.), and a marked gradient was found between the pulmonary veins and left atrium. Selective angiocardiography demonstrated cor triatriatum, in addition to the complete endocardial cushion defect. At age 4 '/z years corrective surgery was performed, and at operation the cardiac catheterization diagnosis was confirmed. The patient has done well postoperatively, and is to have a follow-up cardiac catheterization next year.
DISCUSSION
Although obstruction to pulmonary venous return is an uncommon cause of pulmonary artery hypertension, it is a form which is amenable to surgical correction. In those patients with pulmonary artery hypertension in whom no cardiac defects have been found, a concerted attempt is usually made to obtain PAW pressures to eliminate the possibility of pulmonary venous obstruction being present. However, in many cases, either because of technical difficulties or because the left atrial pressure has been measured directly, an accurate PAW pressure is not obtained. This is especially the case in patients who have other congenital cardiac defects that could be the cause of the pulmonary artery hypertension. The first 2 cases were found to have pulmonary vein stenosis in addition to other cardiac abnormalities, and have been previously reported in detail (6). One patient also had coarctation of the aorta and an atrial septal defect: the other had a large ventricular septal defect. In each instance a bilateral PAW pressure was obtained at a follow-up cardiac catheterization and this led to the diagnosis of pulmonary vein stenosis. Since there are no suggestive auscultatory findings of pulmonary vein stenosis, and frequently no suggestive radiographic findings as well, the diagnosis depends upon the demonstration of agradient between the PAW and the left atrium, with subsequent visualization by selective pulmonary vein angiography (6). In addition, since pulmonary artery hypertension can develop in patients with unilateral pulmonary vein stenosis (7), bilateral PAW pressure measurement is essential. In Case 111, an elevated PAW pressure and pulmonary artery hypertension led to the diagnosis of cor triatriatum. Cases IV and V serve to again stress the importance of bilateral PAW pressure measurement in all patients who have pulmonary hypertension, even if cardiac defects are present that in themselves are sufficient to be the cause of the hypertension.
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There are additional congenital or acquired cardiac abnormalities, such as mitral stenosis and left ventricular dysfunction, that manifest elevation of the pulmonary venous and PAW pressures. Pulmonary vein stenosis and cor triatriatum are the only cases included in this discussion because these lesions are usually silent by auscultation and are more difficult to document by intracardiac pressure determinations and ci neangiocardiograph y . Pulmonary artery angiography may sometimes confirm the diagnosis of various types of pulmonary venous obstruction. In some instances, such as occurred in the cases presented here, even selective pulmonary artery angiography may not adequately demonstrate the lesion. This is especially true if PAW pressures are not measured, and, thus, the presence of pulmonary venous obstruction is not even suspected. In 4 of the 5 cases presented (I, 11, IV, V) the left atrium had been entered with the catheter and the pressures there were found to be normal. Had bilateral PAW pressures not been obtained, pulmonary venous obstruction might not have even been considered as a cause of the pulmonary hypertension in these patients. An accurate PAW pressure is readily obtained in most patients using an end-hole catheter. Although asking the patient to take a deep breath while the catheter is being advanced into the distal pulmonary artery is helpful in adults, this maneuver is of little use in children due to their lack of cooperation. I n many cases, when difficulties in passage of the catheter into the PAW position are encountered, 1) the use of another more rigid catheter, 2 ) the use of a guide wire to stiffen the catheter, or 3) even the use of a small-diameter catheter to enable passage into the smaller vessels, may be helpful. Flushing the catheter immediately prior to and after the catheter is advanced into the PAW position is also helpful in obtaining a good pressure curve. Once the catheter is properly positioned the criteria for an accurate PAW pressure are: 1) A pressure wave-form similar to a left atrial pressure curve. 2) Withdrawal of a fully saturated blood sample. 3) On withdrawal, the catheter, which is usually tightly held in the PAW position, should "pop" back into the branch pulmonary artery. This should be accompanied by an abrupt change in the pressure contour. With the development of the flow-directed balloon-tipped catheter, good quality PAW pressure tracings can now be quickly and easily obtained in most patients, even under difficult circumstances (8-9). Thus, especially in view of the findings presented in our patients, the measurement of PAW pressures bilaterally is an essential part of the evaluation of all patients with pulmonary artery hypertension.
REFERENCES I . Walston A and Kendall ME: Comparison of pulmonary wedge and left atrial pressure in man. Am Heart J 86:159-164. 1973 2. Fitzpatrick GF, Hampson LG, Burgess JH: Bedside determination of left atrial pressure. Can Med ASSOCJ 106:1293-1298. 1972 3. Hellems HK, Haynes FW, and Dexter L: Pulmonary "capillary" pressure in man. J Appl Physiol 2~24-29, 1949 4. Connolly DC. Kirklin JW and Wood EH: The relationship between pulmonary artery wedge pressure and left atrial pressure in man. Circ. Res 2:434-440, 1954 5 . Samet P, Litwak RS, Bernstein WH, Fierer EM and Silverman LM: Clinical and physiologic relationships in mitral valve disease. Circulation 19:517-530. 1959
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6. Park. SC, Neches WH, Lenox CC, Zuberbuhler JR, Siewers RD and Bahnson HT: Diagnosis and surgical treatment ofbilateral pulmonary vein stenosis. J Thoracic Cardiovasc Surg. 67:755-76 I , 1974 7 . Ferencz C, Dammann J F Jr: Significance of the pulmonary vascular bed in congenital heart disease: V. Lesions of the left side of the heart causing obstruction of the pulmonary venous return. Circulation 16: 1046-1056, 1957. 8. Swan HJC, Ganz W. Forrester J , Marcus H , Diamond G and Chonette D: Catheterization ofthe heart in man with use of a flow-directed balloon-tipped catheter. New Engl. 1 Med 283:447-451, 1970 9. Stanger P. Heyrnann MA, Hoffman JIE, Rudolph AM: Use of the Swan Ganz catheter in cardiac catheterization of infants and children. Am Heart J 83:74%754. 1972
