Intravascular Phonocardiography in Clinical and Experimental Peripheral Pulmonary Artery Stenosis

Intravascular Phonocardiography in Clinical and Experimental Peripheral Pulmonary Artery Stenosis* LEONE MATTIOLI, M.D.,** MAKOTO TAKAGI, M.D.F AND A. N. MOGHADAM, M.D.J

Philadelphia, Pennsylvania Each patient had a t h o r o u g h physical examination, 13 lead electrocardiograms, chest phonocardiograms and chest roentgenograms. A routine right heart catheterization included intracardiac phonocardiography in all but one case, and visualization of the lesions by contrast media in all. The left and the right pulmonary arteries were catheterized using a number 4 or 5 Lehman catheter which was advanced to the wedge position. This was confirmed by image intensified fluoroscopy. Withdrawal pressures were measured by Statham P23DB transducers. Intravascular p h o n o c a r diography was performed by means of barium titanate phonocatheters that were advanced into the pulmonary artery branches until a clear murmur was detected. Chest microphones were then positioned on the side corresponding to the branch entered with the phonocatheter, and simultaneous recordings were obtained. Pressures and sounds were recorded by a multichannel photographic a m p l i f i e r - r e c o r d e r (Cambridge and Electronics for Medicine). Timing of the murmurs was computed using the pulmonic component of the second heart-sound (Fig. 1) and the dicrotic notch of the main p u l m o n a r y artery pressure curve. Visualization of the lesions was obtained by one-plane serial angiography or by cineangiography following the injection of contrast medium in the right ventricle and/or main pulmonary artery.

INTRODUCTION UMEROUS PAPERS HAVE DEALT WITH

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the clinical aspects of peripheral pulmonic stenosis.1"8 The occurrence of murmurs of different duration has been noted in clinical as well as experimental models.9 Emphasis has been placed on the distribution of murmurs of peripheral pulmonic stenosis throughout the lung fields in clinical instances. A study of these murmurs by means of i n t r a v a s c u l a r phonocardiography has not to our k n o w l e d g e been previously reported. The purpose of this paper is to present our intravascular phonocardiography findings in clinical peripheral pulmonic stenosis, as well as the results of our experiments in dogs in whom graded c o n s t r i c t i o n of the p u l m o n a r y artery branches were produced. In these experiments, the mechanical and acoustical events were directly correlated by simultaneous pressures and intravascular sound recording. MATERIAL AND METHODS

Thirteen patients varying in age f r o m one month to seven years with peripheral pulmonic stenosis were studied. The selection of these patients was arranged to provide a variety of hemodynamic conditions from which we could gain most information as to the modalities of production of the murmurs that have been described with these lesions. •From the Department of Pediatrics and the Division of Cardiology, Philadelphia General Hospital. This work was aided by a contract (NR 102470) with the Office of Naval Research, Department of the Navy and by a research grant (HE 07415) from the National Heart Institute of the National Institutes of Health. ••Research Fellow, Pediatric Cardiology, Philadelphia General Hospital. fResearch Fellow, Division of Cardiology, Philadelphia General Hospital. $ Assistant Professor of Pediatrics, University of Pennsylvania and Chief, Section of Pediatric Cardiology, Philadelphia General Hospital.

RESULTS

Bilateral or multiple peripheral pulmonic stenoses were demonstrated in all but one case who had solitary stenosis of the left pulmonary artery. Bilateral or multiple lesions as the sole anomalies were present in three cases. Associated anomalies included partial anomalous pulmonary venous drainage (three cases), ventricular septal defect 625

MATTIOLI, TAKAGI AND MOGHADAM

Diseases of the Chest

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FIGURE

(three cases), atrial septal d ef e ct (two cases), patent ductus arteriosus (one case), pulmonic valvular stenosis (one case). Clinical Data: Except for one case of congestive heart failure (case 1), all the patients were free of symptoms at the time of the study which was prompted by the presence of murmurs. History of maternal rubella was elicited in two cases (cases 1 and 12). These two patients died subsequently, one in congestive heart failure and

MOVE RllMT CLMlCLE

the other with overwhelming E. coli septicemia. Rubella viruses were isolated from the nasopharynx in both patients. Four patients were markedly underdeveloped. All of our patients had systolic murmurs, except for case 13 who had a continuous murmur over the entire left lung field. These murmurs were heard clearly above and below both clavicles, on the lateral chest walls and posteriorly between the scapulae. The peripheral distribution of

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Volume H, No.6 June. 1967

INTRAVASCULAR PHONOCARDIOGRAPHY

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628

MATTIOLI, TAKAGI AND MOGHADAM

these murmurs was characteristic even in the presence of associated anomalies. When ventricular septal defect or patent ductus arteriosus was present, the m u r m u r s of peripheral p u l m o n i c stenosis were best heard posteriorly between the scapulae. External phonocardiograms c o n f i r m e d the auscultatory findings (Fig. 2). Hemodynamic Data: Systolic pressure gradients across a stenotic site were always demonstrated, and occasionally m u l t i p l e gradients were found. With the exception of patient 13, who had a significant diastolic gradient between the main pulmonary artery and the left branch, all of our cases had insignificant or absent diastolic gradients. In all but one instance (case 13), irrespective of the systolic peak (Fig. 3A, 3B and 3C), we found a main pulmonary artery pressure tracing as described previously.4 The descending limb of the main pulmonary artery trunk tracing was steeper than normal and was followed by a deeper dicrotic notch and a low diastolic plateau. The pattern of the main pulmonary artery pressure curve was not influenced by the

Diseases of the Chest

presence of a left-to-right shunt. In case 13, the pressures of the right and main pulmonary arteries were both equally elevated in systole and diastole because of increased pulmonary vascular resistance in the right lung. Electrocardiographic Findings: Right ventricular hypertrophy was present in six patients. In the remainder of the patients, the electrocardiogram was normal. Intravascular Phonocardiography: One or both branches were entered with the phonocatheter. Systolic murmurs were always recorded in a segment of the pulmonary artery branch distal to the stenosis. These murmurs ended with the pulmonic component of the second heart sound. In the absence of associated anomalies, the murmurs produced by the stenosis disappeared as the tip of the catheter was withdrawn across the stenotic site. The murmurs produced by the stenosis of the right pulmonary artery were faintly heard and recorded inside the superior vena cava due to the close anatomic relationship of these two vessels (Fig. 4). Figure 4 illustrates a RIGHT VENTRICLE

4: Intracardiac phonocardiogram during a pullback maneuver from distal right pulmonary artery (RPA) to superior vena cava (SVC).

FIGURE

Volume H, No.6 June, 1967

629

INTRAVASCULAR PHONOCARDIOGRAPHY

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withdrawal tracing of the phonocatheter from the right pulmonary artery to the superior vena cava. The same gain was used for the recording of the murmurs inside the right pulmonary artery and the superior vena cava. The murmurs recorded inside the constricted vessels resembled those recorded on the chest wall (Fig. 5). In cases with associated anomalies, where the murmurs are characteristically produced at the pulmonic valve, the murmur of peripheral pulmonic stenosis was separately identified by the location of the f 0 cu s of maximal

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amplitude. In the presence of a ventricular septal defect shunting directly into the pulmonary artery, the murmur recorded at the pulmonic valve was separated with difficulty from those produced at the stenotic site peripherally. No intravascular phono-cardiogram was available in case 13. Angiography: The following anatomic types of defect were demonstrated: (a) coarctation of right and left pulmonary branches, located in proximity of the main pulmonary artery; (b) coarctation of left pulmonary artery; (c) multiple peripheral

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630

Diseases of the Chest

MATTIOLI, TAKAGI AND MOGHADAM

stenosis beyond the primary branches with post stenotic dilatations; (d) diffuse hypoplasia of pulmonary arteries with dilatation of the main trunk.

MATERIAL AND METHODS

EXPERIMENTAL STUDY

Ten adult mongrel dogs under chloralose anesthesia and assisted respirations were subjected to a mid-sternal thoracotomy. A loop of heavy silk was used to produce a graded constriction in the pulmonary vessels. Catheters for pressure recordings were placed inside the right ventricle and the main pulmonary artery. Double lumen catheters for pressure and sound recordings (barium titanate tip) were advanced through a small collateral into the branch to be constricted and positioned by fluoroscopy distal to the constriction. Recordings were made on a multichannel photographic amplifier recorder (Electronics for Medicine). The following procedures were carried out: 1. Graded constriction of one of the primary branches of the pulmonary artery while pressure was monitored proximal and distal to the constriction. A simultaneous intravascular p h o n o c a r d i o g r a m was recorded beyond the stenosis. 2. Graded constriction of both primary branches while pressures from the right ventricle, main pulmonary artery trunk, the constricted branches, and murmurs from the constricted vessels were simultaneously recorded. 3. Graded constriction of one of the primary branches after complete occlusion of the other. The tracings displayed in the illustrations refer to these instances and contain only pulmonary artery trunk and distal branch pressure as well as intravascular sound tracings from the constricted branch. The gain of the preamplifier employed was kept constant throughout the entire procedure so that the amplitude of the murmurs produced could be qualitatively related to the altered hemodynamic conditions.

Graded constriction of the pulmonary artery branches were created in acute experiments in dogs for the purpose of studying the changes of the main pulmonary artery pressure curve and the hemodynamic basis for the murmurs produced by such lesions.

No significant effect on the main pulmonary pressure curve was produced by varying the degree of constriction of one of the primary pulmonary artery branches. A faint systolic murmur was readily pro-

COMMENTS

The wide transmission throughout the lung fields of the murmurs recorded inside the constricted vessels was the most striking acoustic feature exhibited by our patients. The similarity of the murmurs recorded by the phonocatheter with those recorded on the chest wall adds supportive evidence to the view that murmurs, which are peripherally conducted through the lung fields, are of diagnostic significance in peripheral pulmonic stenosis. Our findings show that a systolic murmur may be produced as a result of peripheral pulmonic stenosis if only a systolic g r a d i e n t exists across the stenotic sites. A continuous murmur necessitates the presence of a significant diastolic gradient. As pointed out by others,9 a reservoir of blood under pressure must exist proximal to the constricted segment in order to have flow in diastole of sufficient volume and velocity to reach murmur threshold. Instances which comply with this premise are the cases of primary or secondary pulmonary hypertension with associated segmental constriction (case 13), multiple peripheral pulmonary artery strictures with post stenotic dilatations,tA1° or severe segmental constriction of one pulmonary branch with increased flow through the narrowed segment.' In all the patients with bilateral or multiple peripheral pulmonic stenosis we have consistendy found main pulmonary artery pressure curves resembling ventricular tracings.

RESULTS

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INTRAVASCULAR PHONOCARDIOGRAPHY

duced by mildly constricting the branch and an early diastolic murmur was produced after applying a constriction sufficient to bring about a diastolic gradient across the stenosis. Constriction of both primary branches of the pulmonary artery resulted in changes of the pulmonary artery trunk pressure curve as follows. Mild degree of constriction resulted in elevation of the pulse pressure of the main pulmonary artery trunk without affecting the diastolic pressure across the stenosis. The descending limb was steeper than in control tracings. The murmurs recorded in either constricted branches were enveloped within the pulmonary artery trunk pressure tracing. No diastolic component was present. Greater constriction resulted in elevation of the diastolic pressure of the pulmonary trunk. The main pulmonary artery pressure curve showed a ventricular pattern (greater rate of descent of main pulmonary artery pressure curve) and a diastolic plateau. The murmurs, louder and more intense, extended through entire diastole.

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More striking results were obtained when one branch, the right, was occluded and the left was gradually constricted. Figures 6, 7 and 8 are examples of such a procedure. It is noteworthy that in order to add a diastolic component to these systolic murmurs, it is always necessary to have a diastolic gradient. The loudness or amplitude of these murmurs (both systolic and diastolic) depends upon the degree of constriction and, for any given reduction of the internal diameter, upon the magnitude of blood flow. The duration of the diastolic component is also directly related to the duration of the diastolic gradient across the constricted segment. COMMENT

Our data have essentially shown that murmurs of various duration may be produced by altering the flow through the pulmonary vasculature. When only a systolic gradient is present is a systolic murmur produced. When a diastolic gradient is present across a segment of the pulmonary arteries, a diastolic murmur is produced, the duration of which is related to the per-

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63 2

MATTIOLI, TAKAGI AND MOGHADAM

Diseasesof the Chest

TABLE I-CLINICAL DATA Murmura Cue No. and Sex Age Site of Stenosis Associated Lesions Systolic Diastolic I Male 6 weeks Bilateral VSD yes no Bilateral yes 7 yean ASD no 2 Male yes 3 Female 5 yean Bilateral None no 7 yean 4 Male Bilateral APVD yes no 5 Male 9 months Bilateral yes None no 6 Male yes 14 months Bilateral None no 7 Female 6 yean Multiple yes APVD no 8 Female 17 months Bilateral yes no PVS 9 Male I year Multiple yes no APVD yes no 10 Male Bilateral ASD 2Y2 yean I month yes no 11 Male Multiple VSD yes no 12 Female 5 months Bilateral PDA yes 13 Male yes 6 months LPA VSD VSD: Ventricular lepta! defect, ASD: Atrial septal defect, APVD: Anomalous pulmonary venous drainage, PVS: Pulmonary valvular stenosis, PDA: Patent ductus arteriosus.

sistence of the gradient through diastole. This information complies with the data reported by others," It is noteworthy that increasing the flow through a branch exerts an enhancing affect on the amplitude and duration of a murmur and is not a necessary premise to the development of a continuous murmur,

TOTAL OC'CLUB ION RP"

Our observations relative to the change of the contour of the pulmonary artery pressure curve in bilateral constrictions support previous similar data.' It is interesting, however, that, in our experiments, a significant elevation of the diastolic pressure was present in severe constriction. This finding has not been clearly outlined in previous works.

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FIGURE 8: Simultaneous recordings of pressure changes and murmurs in a dog with complete occlusion of right pulmonary artery (RPA) and severe constriction of left pulmonary artery (LPA). Note the continuous murmur.

Volume 51, No. 6 June, 1967

INTRAVASCULAR PHONOCARDIOGRAPHY

TABLE 2 — D A T A

Case No. 1 2 3 4 5 6 7 8 9 10 11 12 13

RV 80/0.4 40/0-3 40/0-3 35/0 45/0 30/0 70/7 80/0 65/0-5 100/0-5 35/0-5 55/0-5 100/0

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Presturt* MPA RPA 30/12 80/12 24/3 40/6 40/4 10/4 20/4 35/5 15/10 45/15 15/5 30/5 20/10 60/10 40/15 20/12 38/8 65/8 — 100/8 16/7 35/8 15/8 55/10 100/34 100/34

633

CATHETERIZATION

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RV: Right ventricle, MPA: Main pulmonary artery, LPA, Left pulmonary artery, RPA: Right pulmonary artery, ICPG: Intracardiac phonocardiography. SUMMARY

1. Thirteen patients with pulmonary artery branch stenosis proved by angiography have been presented. 2. All patients, except one, had systolic murmurs audible t h r o u g h o u t both lung fields. One patient had a continuous murmur radiating to the entire left lung field. 3. Intracardiac phonocardiography was done in 12 patients and systolic murmurs localized distal to the stenotic site were recorded. Similarity was found between murmurs recorded on the chest wall and within the stenotic vessel. 4. Main pulmonary artery pressure curves were thought to be strongly suggestive of the diagnosis in all the cases of bilateral or multiple p e r i p h e r a l pulmonic stenosis. 5. Simultaneous pressure and sound recordings have been used to study the mechanisms involved in the p r o d u c t i o n of stenotic murmurs within the p u l m o n a r y vasculature in experimental p r e p a r a t i o n s in dogs. Systolic and continuous murmurs were produced by graded constriction of one or both p u l m o n a r y artery primary branches. The timing and intensity of these murmurs were found to be a function of the magnitude and duration of the pressure gradient created across the stenotic sites.

R E SU MEN

1. Presentamos trece pacientes con estenosis de una rama de la arteria pulmonar comprobada por angiografia. 2. Todos, menos uno, presentaban soplos sist6licos audibles en toda la extensi6n de ambos campos pulmonares. En uno de ellos se comprobaba un soplo sisfoSlico continuo, en toda la extensi6n del campo pulmonar izquierdo. 3. Se obtuvieron fonocardiogramas intracardiac s en doce, registrandose soplos sist61icos localizados distalmente a la estenosis. Los soplos regis* trados sobre la pared del t6rax presentaban similaridad con los que se originaban en el interior de los vasos estenosados. 4. Las curvas de presi6n en la arteria pulmonar principal fueron consideradas de gran significaci
1. Presentation de treize ma l a d e s ayant une st£nose des branches de Tartaric p u l m o n a i r e , trouv£e par l'angiocardiographie. 2. Tous les malades sauf un avaient des souffles systoliques per$us dans les deux champs pulmonaires. Un malade avait un souffle continu irradiant dans tout le champ pulmonaire droit.

634

MATTIOLI, TAKAGI AND MOGHADAM

3. La phonocardiographie intra-cardiaque a 6t6 effective chez 12 malades, et des souffles systoliques situls en aval de la stlnose ont 6t€ enregistr6s. On a trouv6 une ressemblance entre les souffles enregistr£s sur la paroi thoracique et ceux enregistr^s dans le vaisseau stlnosl. 4. Des courbes de pressions des branches principales de Tart^re pulmonaire ont 6t£ consid6r6es comme fortement suggestives du diagnostic dans tous les cas de stlnose pulmonaire plriphlrique bilatlrale ou multiple. 5. Les enregistrements simultanls de pressions et de sons ont €t€ utilises, pour £tudier les m6canismes intlressls dans la production des souffles stlnotiques k Tint^rieur des vaisseaux pulmonaires dans des preparations experimentales c h e z le chien. Les souffles continus et systoliques on 6t6 produits par une constriction graduelle de 1'une ou des daux branches primaires de l'art&re pulmonaire. La chronologie et Tintensit6 de ces souffles a 6t6 trouv^e Stre fonction de la grandeur et de la durle du gradient de pressions cr€6 & travers les endroits stlnosls. ZUSAMMENFASSUNG

1. Bericht iiber 13 Patienten mit durch Angiographic erwiesener Stenose eines PulmonalArterien-Astes. 2. Alle Patienten mit einer Ausnahme hatten systolische Gerausche, die man tiber b e i d e n ganzen Lungen horen konnte. Ein Patient hatte ein anhaltendes Gerausch, das iiber das gesamte linke Lungengebiet ausstrahlte. 3. Eine intrakardiale P h o n o c a r d i o g r a p h i e wurde bei 12 Patienten vorgenommen und systolische G e r a u s c h e , die distal zum Sitz der Stenose lokalisiert werden, wurden aufgenommen. Eine Ahnlichkeit fand sich zwischen Gerauschen, die von der Brustwand abgenommen waren und solchen aus dem Gebiet im Inneren der stenotischen GefaPe. 4. Druckkurven des Haptstammes der Pulmonalarterie waren sehr verdSchtig fur eine Stenose als Diagnose, und zwar in alien Fallen bilateraler oder multipler peripherer pulmonaler Stenose. 5. Simultan aufgezeichnete Druck- und Tonkurven wurden benutzt, um die an der Erzeugung der stenotischen Gerausche beteiligten Mechanismen innerhalb der LungengefaP-Struktur zu erheben, und zwar bei experimentellen Tierver-

suchen an Hunden. Systolische und fortlaufende Gerausche liePen sich erzeugen durch schrittweise Konstriktion einer oder beider pulmonaler Hauptarterienaste. Die zeitliche Regulierung und die Starke dieser Gerausche lieP sich als eine Funktion der Grope und Dauer des Druckgefalles ermitteln, das sich durch die Stenosen erzeugen lieP. REFERENCES

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2 GYLLENSWARD, A . , LODIN, H . , LUNDBERG, A . AND MOLLER, T.: "Congenital multiple periph-

3

eral stenosis of the pulmonary artery," Pediatrics, 1 9 : 3 9 9 , 1 9 5 7 . DELANEY, T . B . AND NADAS, A . S . : "Peripheral pulmonic stenosis," Am. ]. Cardiol., 13:

451, 1964. 4 A O U S T S S O N , M . H . , ARCILLA, R . A . , G A S U L , B . M . , BICOFF, J . P . , N A S S I F , S . I . AND L E N DRUM, B . L . : "The diagnosis of bilateral steno-

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5 FRANCH, R .

H.

AND G A Y , B . B . , J R . :

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genital stenosis of the p u l m o n a r y artery branches," Am. J. Med., 3 5 : 5 1 2 , 1 9 6 3 .

6 M C C U E , C . M . , ROBERTSON, L . W . , LESTER, R . G . AND M A U C K , H . P., JR.: "Pulmonary

artery coarctations. A report of 20 cases with review of 319 cases from literature," J. Pediat.,

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6 7 : 2 2 2 , 1965. R O W E , R . : "Maternal

rubella and pulmonary artery stenosis," Pediatrics, 3 2 : 1 8 0 , 1 9 6 3 .

8 EMMANOUILIDES, G . C . , LINDE, L . M . AND CRITTENDEN, I. H.: "Pulmonary artery stenosis

associated with ductus arteriosus following maternal rubella," Circulation, 2 9 : 5 1 4 , 1 9 6 4 .

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"Stenosis of a branch of the pulmonary artery —an additional cause of a continuous murmur over the chest," Circulation, 1 5 : 8 6 5 , 1 9 5 7 .

1 0 SPENCER, M . P . , TOHNSTON, F . R . AND M E R E DITH, J. H.: "The origin and interpretation

of murmurs in coarctation of the aorta," Am. Heart / . , 5 6 : 7 2 2 , 1 9 5 8 .

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J. W.: "Hemodynamics of experimental coarctation of the aorta," Ann. Surg., 1 5 3 : 1 6 3 ,

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For reprints, please write: Dr. A. N. Moghadam, Philadelphia General Hospital, Philadelphia 1 9 1 0 4 .