HOME HELP FEEDBACK SUBSCRIPTIONS ARCHIVE SEARCH TABLE OF CONTENTS		QUICK SEARCH:   [advanced] Author: Keyword(s): Year:  Vol:  Page:

This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Serafin Y. DeLeon David J. Cziperle Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Quinones, J. A. Articles by Fisher, E. A. Search for Related Content PubMed PubMed Citation Articles by Quinones, J. A. Articles by Fisher, E. A. Related Collections Related Article

Ann Thorac Surg 1995;60:1250-1254
© 1995 The Society of Thoracic Surgeons

---

Original Articles: Cardiovascular

Regression of Hypertrophic Cardiomyopathy After Modified Konno Procedure

Departments of Pediatrics and Thoracic-Cardiovascular Surgery, Loyola University Medical Center, Maywood, Illinois

Accepted for publication June 6, 1995.

	Abstract

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Background. Septal myotomy-myectomy has been known to decrease the incidence of sudden death and produce regression in hypertrophic obstructive cardiomyopathy. Use of ß-blockers or calcium-channel blockers generally does not cause regression of the disease.

Methods. Having successfully performed modified Konno procedures in 13 patients with effective relief of diffuse subaortic stenosis, we applied the procedure in 2 patients with hypertrophic obstructive cardiomyopathy. Both patients (18 and 12 years old, respectively) presented with syncope, angina at rest, and dyspnea despite being on calcium channel blocker therapy. The echocardiographic outflow gradients were 66 mm Hg and 88 mm Hg, respectively, with moderate mitral regurgitation.

Results. Both patients had uneventful postoperative course. At 2 years and 1.5 years postoperatively, both patients were free of angina and syncopal episodes. Echocardiography showed absence of outflow gradients and mitral regurgitation. In 1 patient the septal and posterior wall thickness decreased from 3.4 and 1.7 cm preoperatively to 2.6 and 0.9 cm, respectively, postoperatively. In the other patient, the thickness decreased from 2.4 and 0.9 cm preoperatively to 0.8 and 0.7 cm, respectively, postoperatively. Left atrial diameter decreased from 5.4 to 4.7 cm in 1 patient, 3.5 to 2.6 cm in the other.

Conclusions. We believe that the modified Konno procedure could produce more effective relief of obstruction and, therefore, significant regression and further reduction in sudden death in hypertrophic obstructive cardiomyopathy. On the basis of our experience, albeit limited, we encourage its application.

	Introduction

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
See also page 1254.

Surgical relief using septal myotomy-myectomy for outflow obstruction in hypertrophic cardiomyopathy has been shown to significantly decrease the left ventricular wall thickness [1]. Use of ß-blockers or calcium- channel blockers generally does not cause regression of the disease [1].

Although the resting outflow gradient can be significantly reduced or eliminated with septal myotomy-myectomy, some gradients still occur with exercise [2]. It is conceivable that an operation that can produce a more effective relief of the outflow obstruction can lead to further reduction in left ventricular wall thickness. It is also possible that because most sudden deaths occur during or after exercise [3–6], such an operation can significantly affect the incidence of sudden death.

Having successfully performed conal enlargement or modified Konno procedures in infants and children with diffuse or recurrent subaortic stenosis [7, 8], we applied the procedure in 2 young patients with hypertrophic obstructive cardiomyopathy. To demonstrate the feasibility and encourage the use of the approach, we report our experience.

	Material and Methods

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Over a 6-year period ending in July 1993, we performed conal enlargement or modified Konno procedures in 15 patients, two of whom had severe hypertrophic obstructive cardiomyopathy. These 2 patients had the operation in February and July 1993, respectively. The clinical profile, surgical approach, and outcome in both patients were analyzed.

Clinical Profile
Patient 1 was an 18-year-old woman who had a diagnosis of hypertrophic obstructive cardiomyopathy at 14 years of age based on echocardiography and cardiac catheterization data that showed an outflow gradient of 62 mm Hg and moderate mitral regurgitation. The interventricular septum and posterior wall thickness of the left ventricle were 2.8 cm and 1.0 cm, respectively. She was given a calcium channel blocker (verapamil, 120 mg three times a day). She had two uneventful pregnancies at 16 and 17 years of age.

She presented this time with syncopal episodes, angina at rest, and orthopnea. She had been unable to go to school because of increasing exertional angina and dyspnea in the past 12 months. Echocardiogram revealed severe mitral regurgitation and an outflow gradient of 66 mm Hg. The interventricular septum and posterior wall thickness of the left ventricle were 3.4 cm and 1.7 cm, respectively. The left atrial diameter was 5.4 cm. Electrocardiogram revealed severe left ventricular strain.

Patient 2 was a 12-year-old boy who was diagnosed to have hypertrophic cardiomyopathy at 7 years of age. The patient was asymptomatic except for mild exertional dyspnea. The patient was not allowed to participate in strenuous sports. One week before admission, he was seen because of increasing exertional angina and dyspnea. Echocardiography showed basal outflow gradient of 20 mm Hg and moderate mitral regurgitation. He was given a calcium channel blocker (verapamil, 80 mg three times a day). The patient started experiencing episodes of severe rest pain, dyspnea, and near syncopal episodes just before admission. Echocardiogram on admission revealed an outflow gradient of 88 mm Hg. The septal and posterior wall thickness of the left ventricle were 2.4 and 0.9 cm, respectively. Left atrial diameter was 3.5 cm.

Operative Techniques
Details of the modified Konno procedure have been reported previously [7, 8]. Cardiopulmonary bypass and moderate systemic hypothermia (28°C bladder temperature) were achieved through ascending aorta and bicaval cannulation through the right atrial wall. Myocardial protection was accomplished with an initial antegrade blood cardioplegia followed by retrograde infusion given every 10 minutes. Ice slush was also applied topically to the heart.

Because of the peculiarity of the anatomy of the right ventricle, the infundibular incision was longitudinal in patient 1 and transverse in patient 2. An ascending aortotomy was performed for guidance in the incision of the conal septum and protection of the aortic valve. The conal incision was extended between the aortic valve and the left ventricle body. Although muscles were resected on both sides of the conal incision, resection was performed predominantly to the left of the incision.

The conal septum was then enlarged with a polytetrafluoroethylene patch that was sutured in place with continuous 4-0 monofilament suture, reinforced with four to six pledgeted braided sutures. The infundibulum was also enlarged with a polytetrafluoroethylene patch.

	Results

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Early Results
The postoperative course was unremarkable in both patients except for the occurrence of transient intermittent heart block in patient 1. Left bundle-branch block developed in both patients.

Echocardiogram in the immediate postoperative period in both patients showed no outflow gradients. The mitral regurgitation in both patients either disappeared or became mild.

Late Results
Both patients have been free of angina and syncopal episodes 2 years and 1.5 years postoperatively.

Echocardiography at 2 years postoperatively in patient 1 showed absence of gradient or mitral regurgitation. The septal and posterior wall thickness of the left ventricle were 2.6 and 0.9 cm versus 3.4 and 1.7 cm preoperatively, respectively. Echocardiography at 1.5 years postoperatively in patient 2 showed a wide open left ventricular outflow tract (Fig 1), absence of outflow gradient, and mild mitral regurgitation. The septal and posterior wall thickness of the left ventricle were 0.8 and 0.7 cm versus 2.4 and 0.9 cm preoperatively, respectively (Fig 2). The left atrial diameter in patient 1 decreased from 5.4 to 4.7 cm and in patient 2 from 3.5 to 2.6 cm, indicating improvement in left ventricular compliance and decrease in mitral regurgitation (Table 1).

View larger version (58K): [in this window] [in a new window]   Fig 1. . (A) Preoperative echocardiogram of patient 2 showing severe thickness of the septum (S) and obstruction of the left ventricular outflow tract. (B) Postoperative echocardiogram showing the patch (arrows) enlarging the left ventricular outflow tract. (Ao = aorta; LA = left atrium.)

View larger version (83K): [in this window] [in a new window]   Fig 2. . (A, B) Preoperative and postoperative echocardiogram (apical view) in patient 1 showing marked reduction in septal thickness (arrowheads) of the left ventricle (LV) 2 years postoperatively. (C, D) Similar views in patient 2 also showing marked reduction in septal thickness 1.5 years postoperatively.

	Comment

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
The presence of arrhythmias or outflow gradients is a major risk for sudden death in patients with hypertrophic cardiomyopathy [3, 9, 10]. Arrhythmias such as nonsustained ventricular tachycardia, sick sinus, or atrioventricular node disease need to be treated medically as they generally can produce hypotensive episodes and inadequate perfusion of the thickened myocardium [9].

Surgical management is generally indicated in the presence of outflow gradients whether basal or dynamic [3, 11–13]. Dynamic obstruction is established when significant outflow gradients develop with extrasystole, Valsalva maneuver, isuprel administration, and other provocative tests. Generally, a basal gradient of 50 mm Hg or more or dynamic gradient of 100 mm Hg or more is considered significant and should be treated surgically. However, as most sudden deaths in hypertrophic cardiomyopathy are related to activity, lesser gradients may still prove to be a major factor when patients undergo more strenuous activities that could not be duplicated with known provocative tests.

Septal myotomy-myectomy is the current procedure of choice for the management of hypertrophic cardiomyopathy with obstruction [14–16]. At present, mitral valve replacement is rarely used, probably because of the success of septal myotomy-myectomy and the problems associated with any valve prosthesis. Mitral valve replacement may still have a role, however, in patients with obstruction in whom the interventricular septum is less than 18 mm in thickness, persistence of mitral regurgitation, or failure of septal myotomy-myectomy [14, 16].

Surgical relief of obstruction in hypertrophic cardiomyopathy has produced consistently better survival compared with medical therapy. In 190 patients, Shah and colleagues [12] achieved a 4-year mortality of 6% with surgical versus 16% with medical therapy. Rothlin and colleagues [13] reported a 10-year survival rate of 80% with operation versus 71% with medical therapy. Seiler and colleagues [3] reported in 139 patients an annual mortality of 2.4% in surgically treated patients versus 3.6% in medically treated patients.

Surgically treated patients with obstructed cardiomyopathy are symptomatically and hemodynamically better compared with medically treated patients. Cannon and colleagues [2] reported postoperative reduction of outflow gradient from 64 ± 38 mm Hg to 4 ± 7 mm Hg, pacing anginal threshold of 16 ± 18 beats/min, postpacing left ventricular end-diastolic pressure from 30 ± 7 mm Hg to 23 ± 7 mm Hg (p < 0.001) and pulmonary arterial wedge pressure from 24 ± 6 mm Hg to 20 ± 5 mm Hg (p < 0.001). They also reported postoperative salutary reduction in great cardiac vein flow, myocardial oxygen consumption, and lactate production. Curtius and colleagues [1] reported postoperative reduction in the thickness of the septum from 24 ± 4.5 mm to 19.8 ± 6.7 mm (p < 0.05) and posterior wall of the left ventricle from 13 ± 1.6 mm to 11.9 ± 2.3 mm (p < 0.05) compared to no reduction or increase in medically treated and untreated patients. Although hypertrophic cardiomyopathy is a primary disease of the myocardium, the development of outflow obstruction probably causes secondary hypertrophy and acceleration of the disease process. Relief of the obstruction then can cause regression of some of the myocardial hypertrophy as seen in our patients and in the experience of Curtius and colleagues [1].

Although Cannon and colleagues [2] have reduced the postoperative outflow gradient under isuprel stimulation from mean of 111 ± 33 mm Hg to 27 ± 31 mm Hg, nevertheless some gradients persist. Further reduction of these gradients with an operation such as the modified Konno procedure may mean further improvement of the surgical results. Such improvements will make the modified Konno procedure quite an attractive alternative provided that the risks associated with the procedure are quite comparable with septal myotomy-myectomy. On the basis of our experience with the modified Konno procedure in patients with hypertrophic cardiomyopathy and those with other forms of diffuse subaortic stenosis, the procedure could be carried out with no mortality and minimal risk [7, 8]. Vouhe and colleagues [17] were also able to achieve comparable results with one death in 11 patients undergoing modified Konno procedures for diffuse subaortic stenosis. The usual complications associated with septal myotomy-myomectomy, such as aortic valve injury, residual ventricular septal defects, and heart block, are also possible complications with the modified Konno procedure, but should be preventable [16].

The outlook of young patients who are 15 years old or younger with hypertrophic cardiomyopathy has been found to be worse than that of adult patients [18]. The incidence of sudden death is higher in this group of patients especially in the presence of a familial history. Progression of the disease, as seen in our patients, seems to be faster. Although 1 of our patients probably had increased outflow gradient after the administration of calcium channel blocker [9], operation was performed instead of further medical manipulation because of the severity of symptoms. In this group of patients, it is probably wise to perform more provocative tests to uncover dynamic obstruction or to perform close follow-up so that early appropriate management can be administered.

	Footnotes

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 
Address reprint requests to Dr Quinones, Department of Pediatrics, Loyola University Medical Center, 2160 S First Ave, Maywood, IL 60153.

	References

Top Footnotes Abstract Introduction Material and Methods Results Comment References

 

1. Curtius JM, Stoecker J, Loesse B, Welslau R, Scholz D. Changes of the degree of hypertrophy in hypertrophic obstructive cardiomyopathy under medical and surgical treatment. Cardiology 1989;76:255–63.[Medline]
2. Cannon RO, McIntosh CL, Schenke WH, Maron BJ, Bonow RO, Epstein SE. Effect of surgical reduction of left ventricular outflow obstruction in hemodynamics, coronary flow, and myocardial metabolism in hypertrophic cardiomyopathy. Circulation 1989;79:755–66.
3. Seiler C, Otto MH, Schoenbeck M, et al. Long term follow-up of medical versus surgical therapy for hypertrophic cardiomyopathy: a retrospective study. J Am Coll Cardiol 1991;17:634–42.[Abstract]
4. Fripp RR. Hypertrophic cardiomyopathy in the adolescent. Pediatrician 1986;13:158–64.[Medline]
5. Maron BJ, Roberts WC, McAllister HA, et al. Sudden death in athletes. Circulation 1980;62:218–29.[Abstract/Free Full Text]
6. Maron BJ, Roberts WC, Edwards JE, McAllister HA, Foley DD, Epstein SE. Sudden death in patients with hypertrophic cardiomyopathy: characterization of 26 patients without functional limitations. Am J Cardiol 1978;41:803–10.[Medline]
7. DeLeon SY, Ilbawi MN, Arcilla RA, et al. Conal enlargement for diffuse subaortic stenosis. J Thorac Cardiovasc Surg 1991;102:814–20.[Abstract]
8. DeLeon SY, Ilbawi MN, Wilson WR, et al. Surgical options in subaortic stenosis associated with endocardial cushion defect. Ann Thorac Surg 1991;52:1076–83.[Abstract]
9. Von Dohlen TW, Frank MJ. Current perspectives in hypertrophic cardiomyopathy: diagnosis, chemical management and prevention of disability and sudden cardiac death. Clin Cardiol 1990;13:247–52.[Medline]
10. Maron BJ, Henry WL, Clark CE, Redwood DR, Roberts WC, Epstein SE. Asymmetric septal hypertrophy in childhood. Circulation 1976;53:9–19.[Abstract/Free Full Text]
11. Goodwin JF, Oakley CM. Medical and surgical treatment of hypertrophic cardiomyopathy. Eur Heart J 1983;4(Suppl F):209–14.[Medline]
12. Shah PM, Adelman AG, Wigle D, et al. The natural (and unnatural) history of hypertrophic obstructive cardiomyopathy. Circ Res 1974;35(Suppl 2):179–95.
13. Rothlin ME, Gobet D, Haberer T, Krayen Buehl HP, Turina M, Senning A. Surgical treatment versus medical treatment in hypertrophic obstructive cardiomyopathy. Eur Heart J 1983;4(Suppl F):215–23.[Medline]
14. Krajcer Z, Leachman RD, Cooley DA, Coronado R. Septal myotomy-myomectomy versus mitral valve replacement in hypertrophic cardiomyopathy. Ten year follow-up in 185 patients. Circulation 1989;80(Suppl 1):57–64.
15. Mohr R, Schaff HV, Puga FJ, Danielson GK. Results of operation for hypertrophic obstructive cardiomyopathy in children and adults less than 40 years of age. Circulation 1989;80(Suppl 1):191–6.
16. Blanchard DG, Ross J. Hypertrophic cardiomyopathy: prognosis with medical or surgical therapy. Clin Cardiol 1991;14:11–9.[Medline]
17. Vouhé PR, Ouaknine R, Poulain H, et al. Diffuse subaortic stenosis: modified Konno procedures with aortic valve preservation. Eur J Cardiothorac Surg 1993;7:132–6.[Abstract]
18. Maron BJ, Fananapazir L. Sudden cardiac death in hypertrophic cardiomyopathy. Circulation 1992;85(Suppl 1):57–63.

This article has been cited by other articles:

				O. Metton, W. B. Ali, O. Raisky, and P. R. Vouhe Modified Konno operation for diffuse subaortic stenosis MMCTS, September 15, 2008; 2008(0915): 3426. [Abstract] [Full Text] [PDF]

				P. T. Roughneen, S. Y. DeLeon, F. Cetta, D. A. Vitullo, T. J. Bell, E. A. Fisher, B. P. Blakeman, and M. Bakhos Modified Konno-Rastan Procedure for Subaortic Stenosis: Indications, Operative Techniques, and Results Ann. Thorac. Surg., May 1, 1998; 65(5): 1368 - 1376. [Abstract] [Full Text] [PDF]

This Article Abstract Alert me when this article is cited Alert me if a correction is posted Citation Map Services Email this article to a friend Similar articles in this journal Similar articles in PubMed Alert me to new issues of the journal Add to Personal Folders Download to citation manager Author home page(s): Serafin Y. DeLeon David J. Cziperle Permission Requests Citing Articles Citing Articles via HighWire Citing Articles via Google Scholar Google Scholar Articles by Quinones, J. A. Articles by Fisher, E. A. Search for Related Content PubMed PubMed Citation Articles by Quinones, J. A. Articles by Fisher, E. A. Related Collections Related Article