bacterium tuberculosis. J Infect Dis 1993; 167:1481-97 9 DeHaven JI, Traynellis C, Riggs DR, TingE, Lamm DL. Antibiotic and steroid therapy of massive systemic bacillus Calmette-Guerin toxicity. J Urol1992; 147:738-42 10 Israei-Biet D, Venet A, Sandron D, Ziza JM, Chretien J. Pulmonary complications of intravesical bacille CalmetteGuerin immunotherapy. Am Rev Respir Dis 1987; 135:763-65 11 Molina JM, Rabian C, D'Agay MF, Modai J. Hypersensitivity systemic reaction following intravesical bacillus CalmetteGuerin: successful treatment with steroids. J Urol 1992; 147: 695-97 12 Williams MH, Yoo OH, Kane C. Pulmonary function in miliary tuberculosis. Am Rev Respir Dis 1973; 107:858-60
Unsuspected Intrahepatic Interruption of Inferior Vena Cava Associated With Floppy Mitral Valve, Mitral Valve Prolapse, and Severe Mitral Regurgitation* Antonio Dellavalle, M.D. ; Flavia Ribichini, M.D. ; and Giuseppe Steffenino, M.D.
We describe a case of unsuspected infrahepatic interruption of the inferior vena cava with hemiazygos continuation in a 67-year-old man presenting with chest pain and evidence of mitral regurgitation. He had no persistent superior vena cava, with the hemiazygos draining directly into the right superior vena cava. Polysplenia and severe mitral prolapse were also present: the latter may represent more than an incidental finding in this condition. This malformation may deserve consideration in adults undergoing femoral right heart catheterization. Chest radiographic studies are the ba(Chest 1994; 106:1226-28) sic clue to the diagnosis. IVC
= inferior vena cava; SVC = superior vena cava
Jn patients with congenital heart disease, the infra-
hepatic interruption of the inferior vena cava (IV C) has a reported prevalence between 0.6 1 and 2.9 percent. 2 This condition may be associated with anomalous position of the heart and viscera in the typical polyasplenia sequence. 3 Concomitant left atrial isomerism and complex cyanotic cardiovascular defects are also described in the literature. Anomalies of pulmonary venous return, pulmonary atresia, atrioventricular canal, cor biloculare, common atrium, transposition of the great ateries, patent ductus arteriosus, and combinations of the above are most often encountered.1-6 Infrahepatic interruption *From the Laboratorio di Emodinamica, Divisione di Cardiolo. gia, Ospedale Santa Croce, Cuneo, Italy. Manuscript received August 12, 1993; revision accepted November 4.
of the IVC is a very rare finding in adults with otherwise normal hearts. We report a case with hemiazygos continuation in a male adult with severe mitral regurgitation. CASE REPORT
A 67-year-old man was admitted to the hospital for a chest pain of 10 min at rest with ECG changes of uncertain significance. His family history was not remarkable: his mother and father had both died after age 70 years and the cause was not known, one sister had died at age 35 years soon after the birth of her first son, and a second one was still alive and healthy about 20 years after moving to a remote country. The patient was well until 7 years earlier, when moderate shortness of breath appeared. At that time a diagnosis was made of paroxysmal atrial fibrillation, moderate mitral regurgitation, and mild arterial hypertension. Symptoms had improved with oral digoxin and nifedipine. At the time of hospital admission, the patient was in no distress, and his chest pain had spontaneously subsided. His arterial blood pressure was 170/ 95 mm Hg. A hyperkinetic left cardiac impulse, a soft first heart sound, and a grade 3 holosystolic murmur at the apex were apparent on physical examination, results of which were otherwise unremarkable. The posteroanterior chest radiograph showed only mild atrial enlargement and a cardiothoracic ratio of 0.42. The ECG showed regular sinus rhythm at 70 beats/ min, and signs of left ventricular hypertrophy with overload. Depression of the ST segment was more marked than on previous tracings and T waves were deeply inverted throughout the precordial leads. The patient had no symptoms during his hospital stay. An echocardiogram showed a slightly enlarged left ventricular chamber (end diastolic diameter = 35 mm / m 2) with normal systolic function, an enlarged left atrium (56 mm), and a marked prolapse of the posterior mitral leaflet. The former appeared grossly thickened, normally inserted, and with no sign of chordal rupture. The color-Doppler examination showed a severe mitral regurgitation. The other chambers were normal, as was the tricuspid valve. Astress test was not performed because of baseline ST segment and T-wave abnormalities. Right and left heart catheterization through the femoral route was performed to evaluate the valvular abnormality and exclude the presence of significant coronary disease, with a view toward possible surgical repair. During the right heart study, the course of the catheter in the upper abdominal tract and through the diaphragm was seen to point to the left of the spine and posteriorly, with a marked curve to the right and anteriorly at the level of the eighth thoracic vertebra, to reach the normally positioned superior vena cava (SVC), the right atrium, and ventricle (Fig 1). The diagnosis of infrahepatic interruption of the IVC was made. Caval angiography showed an enlarged hemiazygos vein continuing the suprarenal segment of the IVC and emptying into the SVC through a dilated segment of the azygos vein (Fig 2). Cardiac angiography and oximetric runs excluded the presence of other lesions, and pulmonary pressures were normal. The left ventricle had a normal end-diastolic volume (87 ml/m 2 ) with an ejection fraction of 65 percent, and a grade 4 mitral regurgitation. The coronary arteries were normal. A complete chest radiographic study was obtained. No IVC shadow was apparent in the lateral projection. In the left anterior oblique projection (Fig 3), the anomalous shadow of the hemiazygos vein appeared to be superimposed on the ascending aorta. A supplemental cardiac ultrasound study was performed. In the subcostal views, a significant obstruction was seen in the great vein approaching the right atrium from below: the latter showed a direct connection with the hepatic veins. An ultrasound study of the abdomen showed
Unsuspected Intrahepatic Interruption of Inferior Vena Cava (Dellavalle, Ribichini, Steffenino)
FIGURE l. Cineangiogram in the posteroanterior projection: anomalous course of the catheter reaching the right ventricle through the femoral route.
polysplenia, with a host of spleens of about 4 em in diameter, and a normal liver. The patient was referred for elective surgical repair or replacement of the mitral valve. DISCUSSION
In the process of cardiac embryogenesis, the definitive IVC is formed during the sixth to eighth weeks. It is derived, cephalad to caudal, from the hepatic vein, right subcardinal vein, subcardinal anastomosis, and right supracardinal vein. 7 Interruption of the IVC with azygos or hemiazygos continuation is due to failure in the junction between right subcardinal and hepatic veins. The infrarenal IVC is usually not involved; the renal veins join the lower portion of the IVC which continues into an enlarged azygos or-less often-hemiazygos vein 7 The azygos/
3. Chest radiograph in the left anterior oblique projection: the anomalous shadow of the hemiazygos vein (arrows) is superimposed on the ascending aorta. FIGURE
hemiazygos system derives from the anterior segment of the supracardinal vein and partly from the posterior cardinal vein. 2 The hemiazygos vein enters the thoracic cavity via the aortic hiatus of the diaphragm and runs in the posterior mediastinum on the left of the spine. It joins the azygos vein after describing an arch to the right and anteriorly, at the level of the seventh or eighth thoracic vertebra. The azygos vein joins the SVC above the SVC-right atrial junction after arching over the root of the right lung.7 Most often the hemiazygos empties into a persistent left
FIGURE 2. Contrast injection irr the posteroanterior projection: a dilated hemiazygos joins the superior vena cava through the azygos.
In our patient, as in only one other reported 2 to our knowledge, the hepatic veins drained into a confluencevessel reaching the right atrium through the caval hiatus. Most reported cases of IVC interruption with azygos/ hemiazygos continuation have been observed in children and were associated with complex cardiovascular defects.2-4 Less often the diagnosis has been made in young adults 6•8•9 with no other cardiovascular abnormalities or polysplenia. In most reports, the posteroanterior chest radiograph was the initial clue to the diagnosis in that it showed a dilated azygos vein as a convex density at the CHEST / 106 / 5 / NOVEMBER, 1994
right bronchial angle, simulating a mediastinal tumor. This was not the case in our patient due to hemiazygos continuation of the IVC. Two other important signs were apparent in the chest radiograph in our patient, namely, the absence of the IVC shadow in the lateral projection, 5 and the superimposition of the hemiazygos shadow and the ascending aorta in the left lateral oblique projection (Fig 3). The former of these signs may be obscured by a variety of conditions. 6 Coronary sinus rhythm and complete atrioventricular block are sometimes associated with IVC interruptiona·4 Neither was present in our patient. In such cases, complex cardiovascular malformations are almost always present, and the diagnosis is made in early infancy. The association of IVC interruption with prolapse of the posterior mitral leaflet and severe regurgitation in our patient may be purely incidental. A case was reported by Heller et aJ5 in 1971 with azygos continuation of IVC, atrial, septal defect, displaced mitral valve cusp, with "rolled" leaflet, and mitral regurgitation. In conclusion, this case of infrahepatic interruption of the IVC with hemiazygos continuation and absence of persistent left SVC is quite unusual, as is the association with severe mitral prolapse. This malformation, albeit rare, deserves consideration also beyond infancy in patients undergoing femoral right heart catheterization or temporary cardiac stimulation, since it may be very confusing in this setting. A complete chest radiographic study is not routinely performed in patients presenting with chest pain. In our patient, as in most reported cases, it could have
provided valuable clues to this unusual diagnosis. ACKNOWLEDGEMENT: We are grateful to Dr. G. Ugliengo for his help in preparing this report.
1 Anderson RC, Adams P Jr, Burke B. Anomalous inferior vena cava with azygos continuation (infrahepatic interruption of the inferior vena cava). J Pediatr 1961; 59:370-83 2 Dupuis C, Nuyts JP, Christiaens L. Continuation azygos de Ia veine cave inferieure. Arch Mal Coeur 1964; 57:28-49 3 Freedom RM, Ellison RC. Coronary sinus rhythm in the polysplenia syndrome. Chest 1973; 63:952-58 4 Garcia OL, Mehta AV, Pichoff AS, Tamer DF, Ferrer PL, Wolff GS, eta!. Left isomerism and complete atrioventricular block: a report of six cases. Am J Cardiol1981; 48:1103-07 5 Heller RM, Dorst JP, James AE, Rowe RD. A useful sign in the recognition of azygos continuation of the inferior vena cava. Radiology 1971; 101:519-22 6 O'Reilly RJ, GroHman JH Jr. The lateral chest film as an unreliable indicator of azygos continuation of the inferior vena cava. Circulation 1976; 53:891-95 7 Keith JD, Rowe RD, Vlad P. Heart disease in infancy and childhood. New York: Macmillian Publishing Co Inc, 1978; 459-70 8 Matsuoka T, Kimura F, Sugiyama K, Nagata N, Takatani 0. Anomalous inferior vena cava with azygos continuation, dysgenesis of lung, and clinically suspected absence of left pericardium. Chest 1990; 97:747-49 9 Petersen RW. Infrahepatic interruption of the inferior vena cava with azygos continuation (persistent right cardinal vein). Radiology 1965; 84:304-07
Unsuspected Intrahepatic Interruption of Inferior Vena Cava (Dellavalle, Ribichini, Steffenino)