Hemodynamic and angiographic findings are described in a 27-year-old patient, who had undergone surgical operation for subvalvular membranous aortic stenosis. Left ventriculography revealed persistence or regrowth of the subvalvular fibrous ring, and hemodynamic data revealed associated dynamic obstruction of the left ventricular outflow tract. The authors emphasize the importance of uncovering associated dynamic obstruction by provocative maneuvers and use of Beta blockers

Anbe, Daniel T.

Drake, Ellet H.

Goldstein, Sidney

Karo, James J.

Khaja, Fareed

Madrazo, Armando Cesar

Torbey, Peter

English

Henry Ford Health System Scholarly Commons

Henry Ford Hospital Medical JournalVolume 24 | Number 3 Article 69-1976Subvalvular aortic stenosis associated with dynamicoutflow tract obstruction: A case reportArmando Cesar MadrazoDaniel T. AnbeJames J. KaroPeter TorbeyEllet H. DrakeSee next page for additional authorsFollow this and additional works at: https://scholarlycommons.henryford.com/hfhmedjournalPart of the Life Sciences Commons, Medical Specialties Commons, and the Public HealthCommonsThis Article is brought to you for free and open access by Henry Ford Health System Scholarly Commons. It has been accepted for inclusion in HenryFord Hospital Medical Journal by an authorized editor of Henry Ford Health System Scholarly Commons.Recommended CitationMadrazo, Armando Cesar; Anbe, Daniel T.; Karo, James J.; Torbey, Peter; Drake, Ellet H.; Khaja, Fareed; and Goldstein, Sidney(1976) "Subvalvular aortic stenosis associated with dynamic outflow tract obstruction: A case report," Henry Ford Hospital MedicalJournal : Vol. 24 : No. 3 , 165-172.Available at: https://scholarlycommons.henryford.com/hfhmedjournal/vol24/iss3/6Subvalvular aortic stenosis associated with dynamic outflow tractobstruction: A case reportAuthorsArmando Cesar Madrazo, Daniel T. Anbe, James J. Karo, Peter Torbey, Ellet H. Drake, Fareed Khaja, andSidney GoldsteinThis article is available in Henry Ford Hospital Medical Journal: https://scholarlycommons.henryford.com/hfhmedjournal/vol24/iss3/6Henry Ford Hosp. Med. Journal Vol. 24, No. 3, 1976 Subvalvular aortic stenosis associated with dynamic outflow tract obstruction A case report Armando Cesar Madrazo, M D * , Daniel T. Anbe, M D * , James J. Karo, MD **, Peter Torbey, MD **, Ellet H. Drake, MD. *, Fareed Khaja, M D * , Sidney Goldstein, M D * Hemodynamic and angiographic findings are described in a 27-year-old patient, who had undergone surgical operation for sub-valvular membranous aortic stenosis. Left ventriculography revealed persistence or re-growth of the subvalvular fibrous ring, and hemodynamic data revealed associated dy-namic obstruction of the left ventricular outflow tract. The authors emphasize the importance of uncovering associated dy-namic obstruction by provocative maneu-vers and use of Beta blockers. * Division of Cardiovascular Disease, Department of Medicine. ** Department of Radiology; Address reprint requests to Dr. Armando C. Madrazo, Henry Ford Hospital, 2799 West Grand Blvd., Detroit, Ml 48202 T H E simultaneous occurrence of mem-branous and dynamic subvalvular left ven-t r icular ou t f low obstruct ion has been previously reported.' Surgical removal ofthe fibromembranous obstruction usually abol-ishes both the fixed and dynamic subvalvu-lar gradient. In some patients, however, the dynamic subvalvular gradient persists after the fixed gradient has been relieved and gradually diminishes over a period of time.^ We report the hemodynamic, echocar-diographic, and angiographic findings in a patient in whom the development of symp-toms suggests the occurrenceof dynamic left ventricular subvalvular obstruction ten years after surgical correction of fixed left ven-tricular outflow obstruction due to a fibrous band. 165 Madrazo Case report A 27-year-old Caucasian male underwent a resection of a fibromuscular sobaortic ring at another institution at age 17. Although he had experienced exertional dyspnea since childhood, the preoperative evaluation was prompted by a syncopal episode. At operation, a crescent-shaped fibromuscular band was found extending from the bulging hy-pertrophied ventricular septum to the anterior leaflet of the mitral valve. The band was removed without a septal myotomy or myectomy. The patient's symptoms improved postoperatively, but ne was advised to avoid strenuous activities. The current evaluation was prompted by the development of chest pains and dyspnea in July, 1975. Although the precordial chest pains usually occurred with exertion, they occasionally oc-curred at rest. The dyspnea which occurred with moderate exertion was usually mild. There were alsoepisodes of "fast heart beats" but no paroxys-mal nocturnal dyspnea, orthopnea, or syncope. There was no family history of sudden death or heart disease. Physical examination revealed a blood pressure of 110/80, pulse 80/minute and regular, height 5 '8 " and weight 217 pounds. The carotid pulses were normal. The cardiac apical impulse was forceful and located in the fifth intercostal space, 3 cm to the left ofthe midclavicular line. There were no thrills, gallops or ejection click. The first and second heart sounds were normal and phys-iologically split. A Grade l l l /V I ejection systolic murmur was heard at the base radiating into the carotid vessels. No diastolic murmur was audible. Chest x-rays revealed some left ventricular en-largement and a slightly dilated ascending aorta. There was no calcification in the aortic valve. The IVS AMV PLV Figure 1 Echocardiogram: Note the thin echo (arrows) in the left ventricular outf low tract, suggestive of a systolic anterior motion of the mitral valve. There is no continuity in early and late systole. 166 Subvalvular aortic stenosis electrocardiogram showed left ventricular hyper-trophy with a strain pattern. Pulmonary function tests, hemogram and electrolytes were within normal limits. The echocardiogram (Figure 1) revealed a thin echo in the left ventricular outflow tract, anterior to the mitral valve. Although the anterior mitral leaflet showed systolic anterior motion often ob-served in dynamic muscular left ventricular out-flow obstruction, it was not typical because of the lack of contiguity in early and late systole. There was no septal hypertrophy and the septum to posterior left ventricular wall thickness ratio was within normal limits. Fluttering of the anterior leaflet of the mitral valve was consistent with aortic insufficiency. Cardiac catheterization revealed normal right heart pressures, left ventricular end-diastolic pres-sure, O2 consumption, cardiac output, and ar-teriovenous oxygen difference at rest. The left ventricular systolic pressure was 140 mm Hgat the apex and a 40 mm Hg systolic pressure gradient was documented as the catheter was pulled back to the subvalvular area from the apex with no further pressure drop across the aortic valve (Fig-ure 2). The post ectopic beat showed an additional increase of 44 mm Hg in gradient with no change in the aortic pulse pressure. The Valsalva maneu-ver also increased the gradient. Amyl nftrate inha-lation increased the gradient by an additional 40 mm Hg with a significant fall in systemic arterial pressure (Figure 3). Isoproterenol 0.002 mg IV caused a significant tachycardia, a rise in the systolic gradient to 120 mg Hg, and a fall in systemic arterial pressure (Figure 4). The patient complained of mid substernal pain during the isoproterenol infusion which was relieved as the systolic gradient was abolished with methox-amine. Subsequently, propranolol, 1.0 mg IV was given and the patient was rechallenged wfth iso-proterenol 0.002 mg. At this time, despite a slight tachycardia, only a minimal systolic gradient de-veloped and the patient reported no symptoms (Figure 5). The left ventriculogram showed a mildly en-larged cavity with hypertrophied walls, good con-tractions, and no mitral regurgitation. A narrow subaortic chamber was present (Figure 6). The apical left ventricular cavity was not obliterated in systole. The motion of the anterior leaflet of the mitral valve appeared to be limited. There was no systolic apposition o f the anterior leaflet against the septum. Aortic root angiogram showed mod-erate dilation o f the ascending aorta, three cusps and H- to 2-1- /4-F regurgitation. Coronary arterio-grams were normal. 200mmHg 1^ b L I LV I . II. •Ir v1 1^  sv AO ' i l l if 1 • ^ N 1A U I L W W Figure 2 Fullback recording from left ventricle (LV) to aorta (AO). Note the systolic gradient as the subvalvular chamber (SV) is entered. There is no further pressure drop across the aortic valve. Discussion Fixed subaort ic stenosis is a congeni ta l anomaly character ized by the presence, at the subvalvu lar level , o f a membranous or f ib romuscu lar structure obst ruc t ing the ou t -f low tract o f the left ventr ic le . A rather u n c o m m o n anomaly, it occurs in four to ten percent o f al l cases of congen i ta l left ven-t r icu lar o u t f l o w obstruct ion.^ Re ise ta l classif ied congen i ta l subvalvu lar a o r t i c s tenos i s i n t o d i s c r e t e a n d t u n n e l forms.^ The latter fo rm was seen on l y in 9 of 33 p a t i e n t s s t u d i e d . Based o n a n g i o c a r -167 Madrazo CONTROL I AMYL Figure 3 Simultaneous pressure obtained from the left ventricle and femoral artery. A gradient of 44 mm Hg developed after amyl nitrate inhalation. ZDOmmHg lilillll'lllI ill i'H*i UU U \ M L/ I i [ ii: V( 'v \ j V. V' '"w V iSOPROTEIIENOl Figure 4 Simultaneous pressure tracings obtained from LV and FA. A gradient of 120 mm Hg developed after isoproterenol 0.002 mg IV. 168 Subvalvular aor t ic stenosis PROP PROP + ISOPR Figure 5 Rechallenge with isoproterenol 0.002 mg after pretreatment with Inderal, 1 mg IV. Only a minimal gradient of 14 mm Hg developed. diographic features, Deutsch et al" further classified fixed subaortic stenosis into four types: Type I, a thin membranous diaphragmatic stenosis. Type II, a fibrotic ring stenosis. Type 111, a fibromuscular additional tissue stenosis. Type IV, a tunnel-like stricture of the left ventricular outflow tract. Subvalvular left ventr icular out f low obstruction can also be dynamic in nature related to inotropic state, left ventricular volume, or after-load alterations, causing changes in size of the outflow tract with variable degrees of obstruction such, as in hypertrophic subaortic stenosis. The association of both dynamic and fixed obstruction of the left ventricular outflow tract occurs more infrequently although it has been observed in some p a t i e n t s . T h e dynamic obstruction is attributed to resultant ventricular hypertrophy secondary to a pro-longed f ixed anatomical obst ruct ion. In some patients this could lead to persistence of a subvalvular gradient even after surgical repair. Recently, Bloom et aP have shown thatthis phenomenon is related to abnormal motion of the anterior leaflet of the mitral valve, secondary to severe concentric hy-pertrophy of the left ventricle and the sep-tum. Occasionally, idiopathic hypertrophic subaortic stenosis has been found in associa-tion with fixed subvalvular obstruction.= Al-though anatomical, as well as hemodynamic echocardiographic, and angiographic crite-ria are helpful in differentiating these two entities, they may overlap at times^ and the dynamic obstruction only expresses itself after the fixed obstruction is relieved. 169 Madrazo Figure 6 Left ventricular angiogram In RAO projection. Large arrows indicate subvalvular narrowing (lucency) The small arrows outline the aortic cusps. 170 Subvalvular aortic stenosis Our patient represents a case of discrete subvalvularstenosis associated with dynam-ic outflow tract obstruction present ten years after surgical repair ofthe fixed obstruction. It is possible that the fibrous ring was not completely excised at the time of surgery or that it has recurred as described previously.' The cause of the dynamic obstruction is not entirely clear. Extreme care was taken in avoiding apical catheter entrapment during fluoroscopy and angiography and we do not believe this represents a spurious gradient. It wou ld be expected that any dynamic obstruction secondary to the fibrous band present at the time of operation would have regressed or at least remained unchanged. The improvement in symptoms after surgery suggests that there was at least partial rel ief of the left ventricle outflow obstruction. Echo-cardiography demonstrated a structure in the left ventricular outflow tract which could be a remnant of a subvalvular fibrous ring. Such echoes have been described in patients w i t h discrete subaortic stenosis. ' Since provocative maneuvers were not used dur-ing hemodynamic studies prior to surgery ten years ago, the presence of an associated dynamic obstruction at that time cannot be exc luded. However, the present studies clearly demonstrate the dynamic nature of the outflow tract gradient. Although mostcases of combined discrete and dynamic subaortic stenosis are found in older children, provocative testing of all cases of discrete subaortic stenosis should be considered. The echocardiogram can be used in select ing the patients for phar-macologic testing. The danger of overlook-ing a concomitant dynamic outflow tract obstruction during surgery for subvalvular aortic stenosis has been stressed recently.^-' Early deaths have been reported in the postoperative period due to low cardiac output resulting from the associated func-tional obstruction.'' '" As a precautionary measure to prevent this from occur r ing, some surgeons advocate myotomies at the time of repair of discrete subaortic stenosis.' Beta adrenergic blockade was effective in preventingthis demonstrable dynamic com-ponent to the obstruction ofthe left ventricu-lar outflow tract, and relieving symptoms in our patient. Their use should be emphasized in patients with discrete subaortic stenosis associated with dynamic obstruction. References Bloom KR, Meyer RA, Bove KE, Kaplan S: The association of fixed and dynamic left ventricu-lar outflow obstruction. Am Heart / 89:586, 1975 Reis RL, Peterson LM, Mason DT, Simon AL, Morrow AG: Congenital discrete subvalvular aortic stenosis. C;rculat/on 43 (Supplement I), l-ll, 1971 171 Madrazo 3. KeithjD, Rowe RD and Vlad P: Heart D/sease in Infancy and Childhood. Second Edition, MacMil lan, New York, 1967, p 250 4. Deutsch V, Shem-Toy A, Yahini JR, Neufeld H N : Subaortic stenosis (discrete form). Radi-ology 101:275, 1971 5. Chung Kj, Manning JA, Gramiak R: Echocar-d iography in coex is t ing hyper t roph ic subaortic stenosis and fixed left ventricular outflow obstruction. Circulation 49:673, 1974 6. Roberts WC: Valvular, subvalvular, and su-pravalvular aortic stenosis: Morphologic fea-tures. Cardlovas Clin 5:104, 1973 7. Champsaur G, Trusler GA, Mustard W B : Congenital discrete subvalvular aortic ste-nosis. Surgical experience and long-term fol-low-up in 20 pediatric patients. Br Heart / 35:443, 1973 8. PoppRL, Silverman JF, Franch JW, Stinson EB, Harrison DC: Echocardiographic findings in discrete subvalvular aortic stenosis. Circula-tion 49:226, 1974 9. Block PC, Powel l WJ Jr, D insmore RE, Gladblatt A: Coexistent fixed congenital and idiopathic hypertrophic subaortic stenosis. Am j Cardiol 31:523, 1973 10. Parker DP Kaplan MA, Connolly JE: Co-existent aortic valvular and functional hyper-t rophic subaort ic stenosis. Am / Card io l 24:307, 1969 172 

Subvalvular aortic stenosis associated with dynamic outflow tract obstruction: A case report

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Subvalvular aortic stenosis associated with dynamic outflow tract obstruction: A case report

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