Case reports

A new form of right ventricular outflow obstruction

Case report

James W. Pate, M.D.* Lorin E. Ainger, M.D.** Orin D. Butterick, i!X.D.***

Memphis, Tenn.

0 bstruction to pulmonary blood flow may result from a number of con-

genital cardiac anomalies. Pulmonary val- vular stenosis, infundibular stenosis, pe- ripheral pulmonary artery stenosis, and pulmonary valvular atresia are the more common of these lesions. The present case represents a form of obstruction of the pul- monary outflow tract which apparently has never been reported in an otherwise normal heart.

Case report

The patient was an 8-year-old white girl who was hospitalized for elective repair of a congenital heart lesion diagnosed as pulmonary valvular and in- fundibular stenosis. The lesion had been noted shortly after birth. Growth and development had been slow, but she had no notable symptoms until 4 months prior to admission, when she complained of ill-defined anterior chest pain, dyspnea on eser- tion, easy fatigability, and episodes of weakness and pallor.

Despite a full-term gestation, the child weighed only 4 pounds and 10 ounces at birth. Her mother had experienced no illness during pregnancy. A 9-year-old brother and a maternal grandmother have heart disease of unknown type.

Physical findings were essentially normal except for poor physical development and abnormal cardiac findings. The apical cardiac impulse was palpated

in the fourth left intercostal space medial to the mid-clavicular line. There was a prominent right ventricu’ar parasternal thrust which was hea\.ing in character. A systolic thrill was palpable in the first, second, third, and fourth left intercostal spaces parasternally and in the suprasternal notch. The first heart sound at the apes was accentuated. There was a Grade 4/4 systolic ejection murmur which \vas ‘harsh, long, and crescendo-dec: exendo in character, and of maximal character and maximal intensity in the second left intercostal space para- sternally. The murmur was preceded by a systolic ejection click which was audible only during in- spiration in the second left intercostal space. This murmur was transmitted widely into the wreck, infraclaviculariy on the left, and parasternally toward the cardiac apes and into the back. The second sound at the cardiac base was single and audible only over the aortic area. The electrocardio- gram (Fig. 1) revealed marked right axis deviation and a qK pattern in Lead VI, with sagging of the S-T segments and T-wave inversion, and deep S waves extended over the entire left precordium. This electrocardiogram was interpreted as com- patible with severe right ventricular hypertrophy with “strain.” A chest roentgenogram revealed a normal-sized heart, right ventricular enlargement, a prominent pulmonary artery segment, and clear peripheral pulmonary lung fields (Fig. 2). A clinical diagnosis of severe pulmonary valvular stenosis was made.

Cardiac catheterization revealed a systolic pres- sure gradient of 100 mm. Hg across the pulmortary valve and no evidence of an intracardiac shunt.

From the Thoracic Surgery Section and the Section of Pediatric Cardiology, I2niversity of Tennessee Cojlege “f Medi. tine. Memphis, Term.

Received for publication Nov. 18, 196.3. *hssociate Professor of Surgery. and Chairman, Tholacic Surgery Section. Address: Tboracic Surgery Section, ,r,i.

versit? of Tennessee College of Medicine, 858 Madison Ave., Memphis 3. Ten”. **Associate Professor of Pediatrics, and Chief, Pediatric Cardiolog, ***Instructor in Surgery.

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250 Pate, A in.ger, and Bzdterick

VI VZ v3

VE v3-K v-m

Fig. 1. Electrocardiogram demorlstrating severe right ventricular hypertrophy and “strain.” The nresence of a o wave in Leads Van. \T~H, and VI differentiates sivere right ventricular hypertrophy from complete right bundle branch block.

Selective cinecardioangiography demonstrated a systolic jet into the dilated main pu!monary artery. The infundibular area of the right ventricle ap- peared to be narrowed. ‘The final preoperative diagnosis was pulmonary valvular and infundibular stenosis.

Under extracorporeal circulation and Fluoromar anesthesia the right ventricle was opened. The pulmonary valve was normal, and there was slight infundibular muscular stenosis. Just above the crista supraventricularis was a valvular structure which consisted of a large thickened posterior leaflet (2.8 by 1.2 cm.) adjacent to the septum, and a smaller anterior leaflet (1.0 bv 0.9 cm.). Both leaflets were fixed to the myocardium by a rim of dense fibrous tissue, and had multiple chordae tendineae which attached to both septal and mural papillary muscles, as well as smaller attachments with the chordae of the normal tricuspid valve below (Fig. 3). The tricuspid vale-e appeared to be normal. This entire valvular structure was excised, along with 29 grams of infundibular myocardium.

Microscopic examination revealed cardiac val- vular tissue which appeared to be normal, except for small areas of myxomatous degeneration.

The postoperative course of the patient was un- eventful, she was discharged from the hospital 7

days after operation, and she has had no difficulties since then.

Discussion

This unusual case had all the clinical and hemodynamic findings associated with valvular and infundibular pulmonary ste- nosis. The surgical observation of a normal pulmonary valve initially proved to be disconcerting to the cardiologist until further observation disclosed the true nature of the obstruction. To our knowl- edge, this anomaly in an otherwise normal heart has not been described iu the liter- al urc.

Fig. 2. Posteroanterior roentgenogram of the chest. The heart is slightly enlarged, the pulmonary artery segment full, and the lung vascularity diminished.

Fig. 3. Artist’s interpretation of anomalous tricuspid valve in pulmonary outflow tract.

New form of right ventricular outflow obstruction 251

Ehrenhaft’ excised an anomalous tri- cuspid leaflet which was attached to the papillary muscles by chordae tendineae, but which was unattached at the base, so that the free-floating leaflet produced ob- struction at the pulmonary outflow area. The present case differed considerably from Ehrenhaft’s case, since this was a complete valve, with two leaflets, and was attached to the infundibular area as if at an annulus.

Recently, Levy and associates2 have presented 3 cases of corrected transposition of the great vessels in which accessory valvular tissue produced a subpulmonary stenosis, and McLean3 has reported a case of subaortic stenosis due to reduplication of the mitral valve leaflets.

Summary

A case of obstruction of pulmonary tract outflow due to reduplication of the tricuspid valve in the right ventricular outflow tract has been presented. Surgical excision of this structure was successful.

REFERENCES

Ehrenhaft, J. L., Theilen, E. O., and Fisher, J.: Ectopic tricuspid leaflet producing symptoms of infundibular pulmonic stenosis Ann. Surg. 150:937, 1959. Levy, M. J., Lillehei, C. W., Elliot, L. P., Carey, L. S., Adams, P. J., Jr., and Edwards J. E.: Accessory valvular tissue causing sub! pulmonary stenosis in corrected transposition of the great vessels, Circulation 27:494, 1963. McLean, L. J. D., Culligan, J. A., and Kane, D. J.: Subaortic stenosis due to accessory tissue on the mitral valve, J. Thoracic 8r Cardiovas. Surg. 45:382, 1963.