Straight back syndrome with pulmonary venous obstruction

Straight Back Syndrome with Pulmonary Venous Obstruction* ROBERT ( . I EINILV H . M .D ., .1 . WARREN HARTHORNE . M .D . and ROBERT E . DtnsMoRR, M .D .

Boston, Massachusetts

cut . loan the posterior manubrimn to the anterior third thoracic vertebrae . 3 .8 cm . from posterior xiphoid to tie anterior nintli thoracic vertebrae and 5 .0 cm . from the posterior sternuut to the anterior eighth thoracic vertebrae . The electrocard¢ugrren, recorded a vertical QRS axis, horizontal P axis, and negative P and (Is waves in V, (Fir . 21 . A phonocardigrtn indicated that the diastolic ml'nnur began with the aortic second sound . 1'u(nnmarr, function tests showed a maximal breathing capachy of l49 L . ; min . 179 per cent of predicted capacity) and an unobstructed vital capacity of 3 .4 L. (65 per cent of predicted capacity ; . Right and left heart catheterualian was performed through the right median cubital vein and right brachial artery . Oxygen sampling revealed no evidence of left to right shunting . The cardiac output, determined by the direct Fick principle .. was normal at Test and with exercise Right bundle branch block appeared during the studs . Right ventricular enddiastolic (pre-0 and right atrial mean pressures were normal . The right atrial pressne rose with deep inspiration, therein suggesting reduced right ventrint. 'I' he pulmonary arterial pressure tar compliance was 38 10 mm . L Ig (mean 171 at rest and rose W48 !18 mm . Hg (mean 32) with exercise . 'I he pulmonary capillary mean pressure (measured with a No . 7 F ( '.ournand catheter in the right middle and lower lung fields) rose from 1(1 to 22 mm . Hg, and the left ventricular mean diastolic pressure fell from 4 to 1 mm . If4 . A Shirey catheter via, therefore passed retrograde into the Left atrium" to assess the mitral valve, When the patient was in a nonbasal state after exercise, no untrat gradient was found . Puhnonary capillary and left atrial pressures were recorded simultaneously after strain gauge balance was verified, and a mean gradient of 5 mot . Hg was nteastrred (Fig . 3) . Pulmonmi angtugraphy with a No . 9 F N .I .H . Catheter rip in the main pulmonary artery showed slight regurgitation into the right ventricle, normal pulmonary

C OMPRI.SSION of the heart betwccil spine end sternum is seen in fleets excatatuln and straight back syndronlc .' The he, :odcna:n :c inanifestalions arc similar and are generally understood to involve the right side of the heart . We believe the following case demonstrates abnorrnatities it the pulmonary reuous side and offers an explanation for sonic of the clinical alterations in this condition .

C

C'.,sr Klu •t ttrr A 17 teat old man wee admitted for cardiac ta,h,terization to evaluate a heart murmur discovered during an Annv induction phyoical examination . 'Rheas was no history of rlietunatie fever and no eardiurespiratory disability . On eraminatios . the patient leas 51t . . 9 in . fall and weighed 115 If, . Blood pressure and pulses reeve normal . The chest we., narrowed in the anleroposterior plane primarily by a deep imvaid position of a straight thoracic spine hums also y .,light xiphofd depression (big . I ) . 'lIc e ttas a moderate v-,toii, lift at the lower tell sternal bouder, and both aorta and pulmonic salts closure were palpable at the upper left sternal burden . the aortic closure sound was louder than the pulmonic . and the split incised normally with inspiration . An rant systolic diamond-shaped, slightly veluistling svstotie mwrmur ors grade 3~6 at the apex, grade 2,6 at the lower It-It sternal border and grade I 6 ntt the upper left uernal border and axilla . A ,grade 1'6 high-pitched each diastolic blowing murmur was heard at the left sternal border and the axilla and medial to the left scapula . Chrsf rorael,enq,rain showed slight displaccmcaI oft he heart to the left with prominence of the main pulmonary artery and an upper pararnediastinal shadow Thought to represent the left innominate vein displaced to the left . The thoracic spine was straight . and the xiphoid area was slightly depressed, measuring 3 ._

' Prom the DeparnnenI of Medicine, flat c .nd Medical School and the General Medical Service of the Massachusetts General Hospital, Boston, Mass . This study was supported in part by U . S . Public Health Service Grant HE 06664-03 . :\ddress fir reprints : .I . Warren liarthoroe . >cn ., General Metrical Service, Massachusetts General hospital, 32 Fruit St ., Boston, Mass . 02114 . 588

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Straight Back Syndrome

Photographs of patient . is slight xiphoid depression . Fin . 1 .

A,

the dorsal spine lacks the nor in al outward curve .

arteries and a normal-sized left atrium and left ventricle . The left atrium straddled the spine to the left of center (Fig . 4A) . Contrast material returning from the left inferior pulmonary vein showed apparent compression (Fig . 4B) where that vein crossed anterior to the descending aorta .

In both pectus exeavatuni and the straight back syndrome there may be palpable pulntunary arterial pulsations,' systolic murmurs,'" elevation of the right atria) and right ventricular end-diastolic pressures with and without a restrictive "dip and plateau" pattern 3 's , e and small right ventricular outflow gradients . 1,7 Additionally, in pectus excavaturn, investigators have found compression of the innominate vein between the innominate artery and the sternum," soft diastolic murmurs° and limited cardiac output response to exercise . 10 A negative P wave and a qr complex in V I have been attributed to cardiac rotation, V t recording a right atrial "intracavitary" potential ." The systolic and diastolic murmurs in our case arc atypical . The systolic ejection murmur in cardiac compression is Usually maximal at the left sternal border, not the apex . Diastolic murmurs, although described,'," are rare and may represent other abnormalities . Because of tinting and radiation, the most likely source of the diastolic murmur in our case was aortic incompetence, and the demonstrated pulmonic regurgitation was probably artifactual . Whether compression alone can cause aortic incompetence is uncertain . Elevation of pulmonary arterial pressure in pectus

B,

there

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DISCUSSION

VOLUME 21, APRIL 1968

589

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Electrocardiogram showing vertical QRS axis, horizontal P axis, and an "intracavitary" pattern in lead V 1 . Pm . 2 .



Leinbach et al .

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Sirnutlaneous left atriat (dolled lines) and pulmonary wedge (It) pressures.

of 5 mm . Hg

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at rest .

excavatum is rare, generally low-grade12 " and unexplained . Similarly, elevations of pulmonary capillary pressure have not been further explored . Reusch's patient, 14 a 25 Year old woman with mild sternal depression, had a resting pulmonary arterial pressure of 33/14 and a pulmonary capillary pressure of 16%10 nun . Hg . He also may have had mild mitral regurgitation (no angiograms were obtained) . Bcvcgardl° described a 63 year old woman with severe sternal depression whose pulmonary arterial pressure rose to 43/18 mm . Hg (mean 29) and pulmonary capillary mean pressure to 19 (cardiac output 8 .1 L. /min .) on moderate supine exercise ; and Diaz et al . 16 reported on a 35 year old man with dyspnea on heavy exertion whose rating pulmonary arterial pressure was 43/24 mm- Hg (mean 32) and pulmonary capillary mean pressure 12 .5 (no cardiac output determined) . In neither of the latter 2 cases were left-sided recordings obtained . Finally, Ravitch 12 presented a 28 year old man with severe sternal depression, dyspnea, orthopnea and atrial fibrillation . When the heart rate was controlled by digitalis, the right ventricular pressure was 55 /2 mm . Hg, and the cardiac index 1 .4 L./coin ./M .2. 1\o pul-

monary arterial nor pulmonary capillary pressures were presented . Following corrective thoracic cage surgery the right ventricular pressure fell to 36/6 mm . ifg with a cardiac index of 2 .6 (normal sinus rhythm) . The findings in these cases might be explained by pulmonary venous obstruction . In our patient the elevation of pulmonary arterial pressure appeared to be secondary to elevation of pulmonary capillary pressure . Pulmonary wedge recordings were the same from several positions in the right lung, and although the clean left atria[ and wedge pressures differed, their wave forms were similar . The position of the venous obstruction could not he precisely located by pressure recording because the retrograde catheter could not be advanced into pulmonary veins . Pulmonary angiography revealed two possible sites of

there was venous compression where the left inferior pulmonary vein crossed anterior to the descending aorta ; (2) the left atrium was compressed against the spine . The overlapping of left atria) and spinal shadows seen in Figure 4A cannot be explained by atrial obliquity and probably represents atrial indentaobstruction : (1)

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Straight Back Syndrome

591

A

B

Frc . 4 . Pulmonary angiogram . A, left atrial phase (lateral view) . The spine (broken line) and left atrial shadows overlap with probable indentation of the left atrium . The catheter is in the main pulmonary artery . B, venous phase (anteroposterior view), There is apparent obstruction to flow (arrow) where the left inferior pulmonary vein crosses anterior to the descending aorta (broken lines),

tion . Since the indentation did not cause elevation of the left atrial pressure and since the elevated pulmonary capillary pressures were measured on the right, the probable site of obstruction was the,junction of the right pulmonary veins and the posterior left atrium . The left upper pulmonary vein was possibly uninvolved . However, wedge measurements could not he made in this position, and the contrast effluence

nary hypertension secondary to elevation of pulmonary venous pressure . Angiography dem-

was uniform in all lung fields . We therefore conclude that this patient with sternospinal cardiac compression showed puhvonary venous obstruction . We consider this obstruction to be the cause of his mild pulmonary hypertension and propose that it may be a mechanism of dyspnea occasionally encountered in this condition .

ACKNOWLEDGMENT

SUMMARY

A 19 year old man with marked straightening of the thoracic spine and slight xiphoid depression was found to have during exercise pulmoVOLUME 21, APRIL 1968

onstrated both compression of the left inferior pulmonary vein against the descending aorta and "pinning" of the left atrium against the spine . Pulmonary venous obstruction may explain dyspnea in some cases of sternospinal cardiac compression .

We thank Dr. James C. Currens for permission to publish this case . REFERENCES

The "straight back syndrome ." A new cause of pseudo-heart disease. Am . J. Lardml ., 5 : 333, 1960. 2 . Smauy, E. K . and SoNEs, F . M . Retrograde transaortic and mitral valve catheterization . Am. J. Cordial ., 18 : 745, 1966 . 3 . De Leox, A . C ., JR ., PERLOFP, J. K ., Twtoo, H . and Mgto, M. The straight back syndrome. Clinical cardiovascular manifestations. Cireulaiion, 32 : 193, 1965 . 1 . RAWLINGS, M . S .

592

Leinbach et al .

4 . DATEY, K . K ., DESHMUKH, M . M ., ENGINEER, S . D . and DALVI, C . P . Straight back syndrome . Brit . Heart J., 26 : 614, 1964 . 5 . SERRA fro, M . and KEZDI, P . Absence of the physiologic dorsal kyphosis . Cardiac signs and hemodynamic manifestations . Ann . Int . Med ., 58 : 938, 1963 . 6 . LYONS, H . A ., Zoom, M. N . and KELLY, J. J„ JR . Pectus excavatum ("funnel breast"), a cause of impaired ventricular distensibility as exhibited by right ventricular pressure pattern . Am. Heart J ., 50 : 921, 1955 . 7 . FABRICUS, J ., DAVIDSEN, H . G . and HANSEN, A . T . Cardiac function in funnel chest. Dan . M . Bull ., 4 : 251, 1957 . 8 . GEARY, F . J ., ALTMAN, A. R ., BORRELLI, F . J . and GLASSER, S . T. Pectus excavatum as cause of compressed innominate vein syndrome, New York J. Med ., 66 : 1346, 1966 . 9 . ERNBERG, T. The symptom-complex in cor planum . Acta med. scandinav ., 262 (Suppl .) : 51, 1951 .

10. WACHTEL, F . W ., RAVITCH, M . M ., and GRISHMAN, A . The relation of pectus excavatum to heart disease . Am . Heart J., 52 : 121, 1956 . 11 . DE OLIVEIRA, J . M ., SAMBHI, M . P. and ZIMMERMAN, H. A . The electrocardiogram in pectus excavatum. Brit. Heart J., 20 : 495, 1958 . 12 . RAVITCH, M . M . Pectus excavatum and heart failure . Surgery, 30 : 178, 1951 . 13 . ACTIs-DATO, A ., GENTILLI, R . and CALDERINI, P . L'emodinamica Gel pectus excavatum . Minerva cardiaangiol ., 11 : 121, 1963, 14 . REUSCH, C . S. Hemodynamic studies in pectus cxcavatum . Circulation, 24 : 1143, 1961 . 15 . BEVEGARD, S . Postural circulatory changes at rest and during exercise in patients with funnel chest, with special reference to factors affecting the stroke volume . Acta med . scandinav ., 171 : 695, 1962 . 16 . DIAZ, F . V ., PEtous, A . N., CONZALES-VALDES, F ., GRANDA, F . G. G ., GRANADOS, A . and CASAR, F . P. Un caso de "pectus excavatum ." Rev, espan. cardiol ., 14 : 866, 1961 .

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