- Email: [email protected]
Warm heart operation in a patient with myotonic dystrophy
Ann Thorac Surg 1996;62:1203-5
suture technique. The s e g m e n t of ascending aorta was replaced with a 30-mm Hemashield tube graft (Meadox Medicals, Oakland, NJ), a n d coronary bypass grafts were constructed with s a p h e n o u s vein to the obtuse marginal b r a n c h of the circumflex coronary artery a n d with the left internal thoracic artery to the left anterior d e s c e n d i n g coronary artery. The heart was deaired, temporary atrial and ventricular pacing wires were attached, a n d the patient was r e w a r m e d and separated from bypass without difficulty. The postoperative course was notable for mediastinal bleeding that necessitated reexploration. No surgical bleeding site was identified. The patient was extubated the day after operation and r e m a i n e d in complete heart block. A p e r m a n e n t DDD pacemaker was inserted u n d e r local anesthesia on postoperative day 6. She was discharged home 3 days later and r e m a i n s in good health at 6-month follow-up.
Comment Acute dissections of the ascending aorta can have varied presentations, but clinical a n d electrographic evidence of complete heart block as an initial feature is rare. Large series often describe no instance of this p h e n o m e n o n [1], and reported cases of the combination are i n f r e q u e n t [2-4]. W h e n complete heart block occurs, the m e c h a n i s m has b e e n described as rupture of a dissecting h e m a t o m a into the aortoatrial space. The h e m a t o m a then extends through the interstitial tissue of the atrial m y o c a r d i u m a n d progresses down the interatrial septum to an area near the central fibrous body of the heart, the atrioventricular node a n d the b u n d l e of His [2]. Here hemorrhage frequently involves the transitional cell zone of the atrioventricular junction p r o d u c i n g heart block, which may be transient [3]. A h e m a t o m a may also dissect through interstitial tissue of the atrial m y o c a r d i u m to the s u b i n timal layer of the right atrium (leading to r u p t u r e a n d h e m o p e r i c a r d i u m [2]) or down the interventricular septurn (leading to tricuspid insufficiency [5] or rupture into the right ventricle [6]). Rarely, progression of an aortic dissection down the right coronary artery may also produce complete heart block [7]. As well, at least 1 case has b e e n reported from an autopsy series where complete heart block accompanied aortic dissection without the presence of h e m a t o m a of the atrial septum or any other discernible cause [81. In the present case, we p r e s u m e the m e c h a n i s m involved a dissecting hematorna in the atrial septum, b u t we have no histologic confirmation and other causes are possible. However, the absence of (1) an antecedent history of b r a d y a r r h y t h m i a s a n d (2) coronary occlusions at preoperative arteriography causes us to favor this mechanism. If the p r e s u m e d h e m a t o m a of the atrial septum was present, the decision to replace the aortic valve may have b e e n advantageous. Aortic valve replacement, unlike resuspension, is likely to close the site of origin of a dissecting h e m a t o m a into the atrial septum, and may lessen the risk of s u b s e q u e n t rupture. In prior cases where surgical repair has been attempted without © 1996 by The Society of Thoracic Surgeons Published by Elsevier Science lnc
CASE REPORT SAKAIET AL MYOTONIC DYSTROPHY
1203
aortic valve replacement, no surgical survivors were reported. Because of the grave prognosis associated with aortic dissection presenting with heart block, urgent surgical intervention is advised.
References 1. Slater EE, DeSanctis RW. The clinical recognition of dissecting aortic aneurysm. Am J Med 1976;60:625-33. 2. Yacoub MH, Schottenfeld M, Kittle CF. Hematoma of the interatrial septum with heart block secondary to dissecting aneurysm of the aorta. A clinicopathologic entity. Circulation 1972;46:537-45. 3. Thiene G, Rossi L, Becker AE. The atrioventricular conduction system in dissecting aneurysm of the aorta. Am Heart J 1979; 98:447-52. 4. Moar N, Lorber A, Weiss D. Atrioventricular block complicating dissecting aneurysm of the aorta. Int J Cardiol 1987;15: 352-4. 5. Vvas PR, Wright CB, Drieger H, Flege JB Jr. Tricuspid incompetence resulting from retrograde aortic dissection. J Cardiovasc Surg 1987;28:585-7. 6. Perryman RA, Gay WA. Rupture of dissecting thoracic aortic aneurysm into the right ventricle. Am J Cardiol 1972;30: 277-81. 7. Kamp TJ, Goldschmidt-Clermont PJ, Brinker JA, Resar JR. Myocardial infarction, aortic dissection, and thrombolytic therapy. Am Heart J 1994;128:1234-7. 8. Levinson DC, Edmeades DT, Griffith GC. Dissecting aneurysm of the aorta: its clinical, electrocardiographic and laboratory features. A report of fifty-eight autopsied cases. Circulation 1950;1:360-87.
Warm Heart Operation in a Patient With Myotonic Dystrophy Tetsuro Sakai, MD, Shigehito Miki, MD, Yuichi Ueda, MD, Takuya Nomoto, MD, Shuji Hashimoto, MD, a n d Kazuya Takahashi, MD Departments of Cardiovascular Surgery and Neurology, Tenri Hospital, Tenri, Nara, Japan
Myotonic dystrophy is the most severe form of myotonic disorder. Hypothermia or hyperkalemia may cause generalized muscle contraction during heart operations. We successfully repaired an atrial septal defect and pulmonary stenosis in a patient with myotonic dystrophy using systemic normothermia with continuous normokalemic coronary perfusion. This is the second reported case of a patient with myotonic dystrophy who underwent a cardiac operation.
(Ann Thorac Surg 1996;62:1203-5) Yotonic dystrophy (MD) is a rare a n d the most severe form of adult muscular dystrophy, inherited as an autosomal d o m i n a n t trait with a prevalence of
M
Accepted for publicationApril 19, 1996. Address reprint requests to Dr Sakai, Department of Cardiovascular Surgery, Tenri Hospital, 200 Mishima, Tenri, Nara, Japan 632. 0003-4975/96/$15.00 PII S0003-4975(96)00397-9
1204
CASE R E P O R T SAKA[ ET AL MYOTON1C DYSTROPHY
Ann Thorac Surg 1996;62:1203-5
¢, ~s
Fig I. Postoperative appearance qf the patient. Ptosis, sternocleidomastoid muscle atrophy, and temporal and masseter muscle wasting are evident.
2.4 to 5.5 per 100,000 of the population [1]. Myotonic dystrophy characteristically shows progressive involvement of skeletal muscle and other organs [1]. Recent genetic studies have revealed that the underlying basis of MD is an unstable trinucleotide repeat sequence in a gene encoding a protein kinase family member [2]. Myotonic dystrophy is a well-known hazard in anesthesia for various kinds of operations [3, 4]; however, cardiac operation with the aid of cardiopulmonary bypass in a patient with MD rarely has been reported [5]. We describe a patient with MD who underwent successful repair of an atrial septal defect and pulmonary stenosis. We employed normothermic cardiopulmonary bypass with continuous normokalemic aortic root perfusion on an empty, beating heart to avoid prolonged muscle contraction or possible cardiac dysfunction caused by hypothermia or hyperkalemia. A 41-year-old woman presented because of easy fatigability. She also complained of muscle weakness of the limb girdle for 2 years. Myotonic dystrophy had been diagnosed in her older sister. The patient showed the classic features of myotonic dystrophy: ptosis, hatchet face, wasted sternocleidomastoid muscles (Fig 1), nasal speech, peripheral and proximal muscle weakness, and percussion myotonia. Chest auscultation revealed a pansystolic murmur at the second left sternal border with fixed splitting of the second heart sound. Hormonal study showed high serum adrenocorticotrophic hormone level and decreased cortisol level, which indicated mild primary adrenal dysfunction. Echocardiography showed a secundum-type atrial septal defect and valvular pulmonary stenosis. The arterial blood gas analysis in room air demonstrated a pH of 7.414, arterial oxygen tension of 54.3 mm Hg, and arterial carbon dioxide tension of 43.1 mm Hg. On the chest x-ray film, the cardiothoracic ratio was 0.67. Electrocardiography showed an atrial flutter.
The patient underwent a cardiac operation on May 26, 1995. She was intubated without incident and given thiamylal sodium and vecuronium bromide intravenously. Anesthesia was maintained with fentanyl citrate, midazolam, oxygen, and nitrous dioxide. A standard median sternotomy was made. Cardiopulmonary bypass was established in the usual fashion. The body temperature was maintained at 37°C throughout the operation. The ascending aorta was cross-clamped. Coronary perfusion was maintained with infusion of warm blood through a 12-gauge aortic root cannula (dlp, Inc, Grand Rapids, MI), and the heart was kept beating (Fig 2). The right atrium was opened immediately after the aortic cross-clamping. Patch closure of the atrial septal defect (45 × 20 ram) and pulmonary valve commissurotomy were performed. She was weaned from cardiopulmonary bypass easily. The postoperative course was uneventful except for a mild respiratory tract infection. She was discharged on the 29th postoperative day and has remained well on an outpatient basis for 9 months.
Comment A variety of anesthetic and operative problems have been reported in patients with MD I3, 4]. One of the major concerns is generalized muscle contraction. Administration of depolarizing muscle relaxants or neostigmine, hypothermia and shivering, or raised serum potassium concentration can cause muscle contraction [3, 4, 6]. The membrane of the myotonic or dystrophic rnyotonic muscle is extremely sensitive to changes in extracellular potassium concentration [6]. The contraction will last for
1\
~\
/
]1
,/"
.{Dr
~~.
iMembrane ] J Oxygenator
(HeatEx.)1
Fig 2. Aortic root pe.rfusion with the blood from a side branch of the arterial line during aorh'c cross-clamping. A 12-gauge aortic root cannula is placed on the ascending aorta. The heart is kept beating. (Ex. - exchanger.)
Ann Thorac Surg 1996;62:1205-7
2 to 3 m i n u t e s followed by slow g r a d u a l relaxation. The response is unpredictable. Blockade of the n e u r o m u s c u lar junction either with n o n d e p o l a r i z i n g muscle relaxants or with nerve blocks cannot p r e v e n t the muscle contraction because the s p a s m originates in the a b n o r m a l m u s cle m e m b r a n e itself [1]. The m a n a g e m e n t of cardiac d y s r h y t h m i a is a n o t h e r concern. The heart is involved in a majority of patients with MD. Every conduction pathw a y can be involved, resulting in sinus bradycardia, atrioventricular block, a n d b u n d l e - b r a n c h block. G e n e r alized myocardial involvement, although not frequent, can cause ventricular dysrhythmia. S u d d e n death due to heart block or ventricular d y s r h y t h m i a has b e e n r e p o r t e d [11. Reports of cardiac operation in patients with MD have b e e n rare. As far as we know, only 1 case has b e e n r e p o r t e d in the English-language literature. Tanaka a n d Tanaka [5] r e p o r t e d a 41-year-old m a n with MD who u n d e r w e n t atrial septal defect closure with the aid of c a r d i o p u l m o n a r y bypass. Theoretically, in cardiac operations in patients with MD, application of systemic h y p o t h e r m i a or h y p e r k a l e mic cardioplegia should be avoided as m e n t i o n e d above. H y p o t h e r m i a can cause generalized muscle contraction in patients with MD, which is h a z a r d o u s in p e r f o r m i n g cardiac operations. Although Tanaka and Tanaka used mild h y p o t h e r m i a (31°C) in their patient with MD without any deleterious effect, application of n o r m o t h e r m i c c a r d i o p u l m o n a r y b y p a s s should be selected. High s e r u m concentration of p o t a s s i u m due to h y p e r k a l e m i c cardioplegia m a y also cause muscle contraction. Furthermore, the impact of h y p e r k a l e m i c cardioplegia on the heart of a patient with MD is not fully understood. Tanaka and Tanaka did not mention their m e t h o d of myocardial protection. In our case, for m y o c a r d i a l protection we u s e d continuous n o r m o k a l e m i c aortic root perfusion on an empty, beating heart with aortic cross-clamping [7]. The root perfusion can be a c c o m p l i s h e d either in an empty, beating heart or in a heart with ventricular fibrillation, but the application in the former seems to be better [8]. In this situation, c l a m p i n g of the a s c e n d i n g aorta has the a d v a n tage of avoiding possible air e m b o l i s m from the beating heart. We also think the connection of the root cannula and the side arm of the arterial line provides stable root pressure. Even if the heart might accidentally eject a large a m o u n t of b l o o d d u r i n g the cross-clamping of the aorta, excessively high p r e s s u r e to the coronary artery could be a v o i d e d with the connection. A l t h o u g h the root perfusion m e t h o d is less effective in myocardial protection than that with cardioplegia, short-term application of this m e t h o d is still valuable in some circumstances [7]. During the procedure, it is i m p o r t a n t to open the right atrium early after aortic cross-clamping for venting to p r e v e n t overdistention of the heart. We think it is m a n d a t o r y to avoid the use of systemic h y p o t h e r m i a or of h y p e r k a l e m i c cardioplegia in cardiac operations in patients with M D unless the safety of these m e t h o d s for patients with MD is fully investigated. © 1996 by The Society, of Thoracic Surgeons Published by Elsevier Science Inc
CASE REPORT YILMAZET AL SUPRAVALVULARAORTIC STENOS1S
1205
References
1. Jozefowicz RF, Griggs RC. Myotonic dystrophy. Neurol Clin 1988;6:455-72. 2. Brook JD, McCurrach ME, Harley HG, et al. Molecular basis of myotonic dystrophy: expansion of a trinucleotide (CTG) repeat at the 3' end of a transcript encoding a protein kinase family member. Cell 1992;68:799-808. 3. Aldridge LM. Anaesthetic problems in myotonic dystrophy. Br J Anaesth 1985;57:1119-30. 4. O'Shea PJ. Pre-existing nervous system disorders and the safety of anaesthesia. In: Taylor TH, Major E, eds. Hazards and complication of anaesthesia. Edinburgh: Churchill Livingstone, 1987:52-75. 5. Tanaka M, Tanaka Y. Cardiac anaesthesia in a patient with myotonic dystrophy. Anaesthesia 1991;46:462-5. 6. Durelli L, Mutani IL Fassio F, Delsedime M. The effects of the increase of arterial potassium upon the excitability of normal and dystrophic myotonic muscles in man. J Neurol Sci 1982; 55:249-57. 7. Kirklin JW, Barratt-Boyes BG, eds. Cardiac surgery. 2nd ed. New York: Churchill Livingstone, 1993:129-65. 8. Buckberg GD, Olinger GN, Mulder DG, Maloney JV Jr. Depressed postoperative cardiac performance. J Thorac Cardiovasc Surg 1975;70:974-88.
Coronary Artery Aneurysm Associated With Adult Supravalvular Aortic Stenosis A h m e t T. Yilmaz, MD, M e h m e t Arslan, MD, Ertu6rul Ozal, MD, H a k a n B~'ng61, MD, H a r u n Tatar, MD, a n d O m e r Yiiksel Ozt/irk, MD Department of Cardiovascular Surgery, Giilhane Military Medical Academy, Ankara, Turkey Two patients, aged 20 and 21 years, with supravalvular aortic stenosis and aneurysms of the coronary arteries are described. In supravalvular aortic stenosis, dilatation of the sinuses of Valsalva and multiple abnormalities of one or both coronary arteries are common. A n e u r y s m of coronary artery has not been well recognized as a lesion associated with supravalvular aortic stenosis. The operation in these patients was limited to relief of the supravalvular obstruction.
(Ann Thorac Surg 1996;62:1205-7) n congenital supravalvular aortic stenosis, coronary artery a b n o r m a l i t y is one of the major associated cardiovascular lesions. The coronary arteries m a y be dilated a n d tortuous because the ostia are b e l o w the site of obstruction a n d e x p o s e d to elevated left ventricular pressure, or they m a y b e c o m e n a r r o w e d by the overhanging, stenosing ring or even c o m p l e t e l y obstructed should the valve cusp b e c o m e a d h e r e n t to the aortic wall [1]. The majority of these a n o m a l i e s are obstructing
I
Accepted for publication April 25, 1996. Address reprint requests to Dr Yilrnaz, GATA Loj Numan Apt No. 5, 06018 Etlik, Ankara, Turkey. 0003-4975196/$15.00 PII S0003-4975(96)00383-9
suture technique. The s e g m e n t of ascending aorta was replaced with a 30-mm Hemashield tube graft (Meadox Medicals, Oakland, NJ), a n d coronary bypass grafts were constructed with s a p h e n o u s vein to the obtuse marginal b r a n c h of the circumflex coronary artery a n d with the left internal thoracic artery to the left anterior d e s c e n d i n g coronary artery. The heart was deaired, temporary atrial and ventricular pacing wires were attached, a n d the patient was r e w a r m e d and separated from bypass without difficulty. The postoperative course was notable for mediastinal bleeding that necessitated reexploration. No surgical bleeding site was identified. The patient was extubated the day after operation and r e m a i n e d in complete heart block. A p e r m a n e n t DDD pacemaker was inserted u n d e r local anesthesia on postoperative day 6. She was discharged home 3 days later and r e m a i n s in good health at 6-month follow-up.
Comment Acute dissections of the ascending aorta can have varied presentations, but clinical a n d electrographic evidence of complete heart block as an initial feature is rare. Large series often describe no instance of this p h e n o m e n o n [1], and reported cases of the combination are i n f r e q u e n t [2-4]. W h e n complete heart block occurs, the m e c h a n i s m has b e e n described as rupture of a dissecting h e m a t o m a into the aortoatrial space. The h e m a t o m a then extends through the interstitial tissue of the atrial m y o c a r d i u m a n d progresses down the interatrial septum to an area near the central fibrous body of the heart, the atrioventricular node a n d the b u n d l e of His [2]. Here hemorrhage frequently involves the transitional cell zone of the atrioventricular junction p r o d u c i n g heart block, which may be transient [3]. A h e m a t o m a may also dissect through interstitial tissue of the atrial m y o c a r d i u m to the s u b i n timal layer of the right atrium (leading to r u p t u r e a n d h e m o p e r i c a r d i u m [2]) or down the interventricular septurn (leading to tricuspid insufficiency [5] or rupture into the right ventricle [6]). Rarely, progression of an aortic dissection down the right coronary artery may also produce complete heart block [7]. As well, at least 1 case has b e e n reported from an autopsy series where complete heart block accompanied aortic dissection without the presence of h e m a t o m a of the atrial septum or any other discernible cause [81. In the present case, we p r e s u m e the m e c h a n i s m involved a dissecting hematorna in the atrial septum, b u t we have no histologic confirmation and other causes are possible. However, the absence of (1) an antecedent history of b r a d y a r r h y t h m i a s a n d (2) coronary occlusions at preoperative arteriography causes us to favor this mechanism. If the p r e s u m e d h e m a t o m a of the atrial septum was present, the decision to replace the aortic valve may have b e e n advantageous. Aortic valve replacement, unlike resuspension, is likely to close the site of origin of a dissecting h e m a t o m a into the atrial septum, and may lessen the risk of s u b s e q u e n t rupture. In prior cases where surgical repair has been attempted without © 1996 by The Society of Thoracic Surgeons Published by Elsevier Science lnc
CASE REPORT SAKAIET AL MYOTONIC DYSTROPHY
1203
aortic valve replacement, no surgical survivors were reported. Because of the grave prognosis associated with aortic dissection presenting with heart block, urgent surgical intervention is advised.
References 1. Slater EE, DeSanctis RW. The clinical recognition of dissecting aortic aneurysm. Am J Med 1976;60:625-33. 2. Yacoub MH, Schottenfeld M, Kittle CF. Hematoma of the interatrial septum with heart block secondary to dissecting aneurysm of the aorta. A clinicopathologic entity. Circulation 1972;46:537-45. 3. Thiene G, Rossi L, Becker AE. The atrioventricular conduction system in dissecting aneurysm of the aorta. Am Heart J 1979; 98:447-52. 4. Moar N, Lorber A, Weiss D. Atrioventricular block complicating dissecting aneurysm of the aorta. Int J Cardiol 1987;15: 352-4. 5. Vvas PR, Wright CB, Drieger H, Flege JB Jr. Tricuspid incompetence resulting from retrograde aortic dissection. J Cardiovasc Surg 1987;28:585-7. 6. Perryman RA, Gay WA. Rupture of dissecting thoracic aortic aneurysm into the right ventricle. Am J Cardiol 1972;30: 277-81. 7. Kamp TJ, Goldschmidt-Clermont PJ, Brinker JA, Resar JR. Myocardial infarction, aortic dissection, and thrombolytic therapy. Am Heart J 1994;128:1234-7. 8. Levinson DC, Edmeades DT, Griffith GC. Dissecting aneurysm of the aorta: its clinical, electrocardiographic and laboratory features. A report of fifty-eight autopsied cases. Circulation 1950;1:360-87.
Warm Heart Operation in a Patient With Myotonic Dystrophy Tetsuro Sakai, MD, Shigehito Miki, MD, Yuichi Ueda, MD, Takuya Nomoto, MD, Shuji Hashimoto, MD, a n d Kazuya Takahashi, MD Departments of Cardiovascular Surgery and Neurology, Tenri Hospital, Tenri, Nara, Japan
Myotonic dystrophy is the most severe form of myotonic disorder. Hypothermia or hyperkalemia may cause generalized muscle contraction during heart operations. We successfully repaired an atrial septal defect and pulmonary stenosis in a patient with myotonic dystrophy using systemic normothermia with continuous normokalemic coronary perfusion. This is the second reported case of a patient with myotonic dystrophy who underwent a cardiac operation.
(Ann Thorac Surg 1996;62:1203-5) Yotonic dystrophy (MD) is a rare a n d the most severe form of adult muscular dystrophy, inherited as an autosomal d o m i n a n t trait with a prevalence of
M
Accepted for publicationApril 19, 1996. Address reprint requests to Dr Sakai, Department of Cardiovascular Surgery, Tenri Hospital, 200 Mishima, Tenri, Nara, Japan 632. 0003-4975/96/$15.00 PII S0003-4975(96)00397-9
1204
CASE R E P O R T SAKA[ ET AL MYOTON1C DYSTROPHY
Ann Thorac Surg 1996;62:1203-5
¢, ~s
Fig I. Postoperative appearance qf the patient. Ptosis, sternocleidomastoid muscle atrophy, and temporal and masseter muscle wasting are evident.
2.4 to 5.5 per 100,000 of the population [1]. Myotonic dystrophy characteristically shows progressive involvement of skeletal muscle and other organs [1]. Recent genetic studies have revealed that the underlying basis of MD is an unstable trinucleotide repeat sequence in a gene encoding a protein kinase family member [2]. Myotonic dystrophy is a well-known hazard in anesthesia for various kinds of operations [3, 4]; however, cardiac operation with the aid of cardiopulmonary bypass in a patient with MD rarely has been reported [5]. We describe a patient with MD who underwent successful repair of an atrial septal defect and pulmonary stenosis. We employed normothermic cardiopulmonary bypass with continuous normokalemic aortic root perfusion on an empty, beating heart to avoid prolonged muscle contraction or possible cardiac dysfunction caused by hypothermia or hyperkalemia. A 41-year-old woman presented because of easy fatigability. She also complained of muscle weakness of the limb girdle for 2 years. Myotonic dystrophy had been diagnosed in her older sister. The patient showed the classic features of myotonic dystrophy: ptosis, hatchet face, wasted sternocleidomastoid muscles (Fig 1), nasal speech, peripheral and proximal muscle weakness, and percussion myotonia. Chest auscultation revealed a pansystolic murmur at the second left sternal border with fixed splitting of the second heart sound. Hormonal study showed high serum adrenocorticotrophic hormone level and decreased cortisol level, which indicated mild primary adrenal dysfunction. Echocardiography showed a secundum-type atrial septal defect and valvular pulmonary stenosis. The arterial blood gas analysis in room air demonstrated a pH of 7.414, arterial oxygen tension of 54.3 mm Hg, and arterial carbon dioxide tension of 43.1 mm Hg. On the chest x-ray film, the cardiothoracic ratio was 0.67. Electrocardiography showed an atrial flutter.
The patient underwent a cardiac operation on May 26, 1995. She was intubated without incident and given thiamylal sodium and vecuronium bromide intravenously. Anesthesia was maintained with fentanyl citrate, midazolam, oxygen, and nitrous dioxide. A standard median sternotomy was made. Cardiopulmonary bypass was established in the usual fashion. The body temperature was maintained at 37°C throughout the operation. The ascending aorta was cross-clamped. Coronary perfusion was maintained with infusion of warm blood through a 12-gauge aortic root cannula (dlp, Inc, Grand Rapids, MI), and the heart was kept beating (Fig 2). The right atrium was opened immediately after the aortic cross-clamping. Patch closure of the atrial septal defect (45 × 20 ram) and pulmonary valve commissurotomy were performed. She was weaned from cardiopulmonary bypass easily. The postoperative course was uneventful except for a mild respiratory tract infection. She was discharged on the 29th postoperative day and has remained well on an outpatient basis for 9 months.
Comment A variety of anesthetic and operative problems have been reported in patients with MD I3, 4]. One of the major concerns is generalized muscle contraction. Administration of depolarizing muscle relaxants or neostigmine, hypothermia and shivering, or raised serum potassium concentration can cause muscle contraction [3, 4, 6]. The membrane of the myotonic or dystrophic rnyotonic muscle is extremely sensitive to changes in extracellular potassium concentration [6]. The contraction will last for
1\
~\
/
]1
,/"
.{Dr
~~.
iMembrane ] J Oxygenator
(HeatEx.)1
Fig 2. Aortic root pe.rfusion with the blood from a side branch of the arterial line during aorh'c cross-clamping. A 12-gauge aortic root cannula is placed on the ascending aorta. The heart is kept beating. (Ex. - exchanger.)
Ann Thorac Surg 1996;62:1205-7
2 to 3 m i n u t e s followed by slow g r a d u a l relaxation. The response is unpredictable. Blockade of the n e u r o m u s c u lar junction either with n o n d e p o l a r i z i n g muscle relaxants or with nerve blocks cannot p r e v e n t the muscle contraction because the s p a s m originates in the a b n o r m a l m u s cle m e m b r a n e itself [1]. The m a n a g e m e n t of cardiac d y s r h y t h m i a is a n o t h e r concern. The heart is involved in a majority of patients with MD. Every conduction pathw a y can be involved, resulting in sinus bradycardia, atrioventricular block, a n d b u n d l e - b r a n c h block. G e n e r alized myocardial involvement, although not frequent, can cause ventricular dysrhythmia. S u d d e n death due to heart block or ventricular d y s r h y t h m i a has b e e n r e p o r t e d [11. Reports of cardiac operation in patients with MD have b e e n rare. As far as we know, only 1 case has b e e n r e p o r t e d in the English-language literature. Tanaka a n d Tanaka [5] r e p o r t e d a 41-year-old m a n with MD who u n d e r w e n t atrial septal defect closure with the aid of c a r d i o p u l m o n a r y bypass. Theoretically, in cardiac operations in patients with MD, application of systemic h y p o t h e r m i a or h y p e r k a l e mic cardioplegia should be avoided as m e n t i o n e d above. H y p o t h e r m i a can cause generalized muscle contraction in patients with MD, which is h a z a r d o u s in p e r f o r m i n g cardiac operations. Although Tanaka and Tanaka used mild h y p o t h e r m i a (31°C) in their patient with MD without any deleterious effect, application of n o r m o t h e r m i c c a r d i o p u l m o n a r y b y p a s s should be selected. High s e r u m concentration of p o t a s s i u m due to h y p e r k a l e m i c cardioplegia m a y also cause muscle contraction. Furthermore, the impact of h y p e r k a l e m i c cardioplegia on the heart of a patient with MD is not fully understood. Tanaka and Tanaka did not mention their m e t h o d of myocardial protection. In our case, for m y o c a r d i a l protection we u s e d continuous n o r m o k a l e m i c aortic root perfusion on an empty, beating heart with aortic cross-clamping [7]. The root perfusion can be a c c o m p l i s h e d either in an empty, beating heart or in a heart with ventricular fibrillation, but the application in the former seems to be better [8]. In this situation, c l a m p i n g of the a s c e n d i n g aorta has the a d v a n tage of avoiding possible air e m b o l i s m from the beating heart. We also think the connection of the root cannula and the side arm of the arterial line provides stable root pressure. Even if the heart might accidentally eject a large a m o u n t of b l o o d d u r i n g the cross-clamping of the aorta, excessively high p r e s s u r e to the coronary artery could be a v o i d e d with the connection. A l t h o u g h the root perfusion m e t h o d is less effective in myocardial protection than that with cardioplegia, short-term application of this m e t h o d is still valuable in some circumstances [7]. During the procedure, it is i m p o r t a n t to open the right atrium early after aortic cross-clamping for venting to p r e v e n t overdistention of the heart. We think it is m a n d a t o r y to avoid the use of systemic h y p o t h e r m i a or of h y p e r k a l e m i c cardioplegia in cardiac operations in patients with M D unless the safety of these m e t h o d s for patients with MD is fully investigated. © 1996 by The Society, of Thoracic Surgeons Published by Elsevier Science Inc
CASE REPORT YILMAZET AL SUPRAVALVULARAORTIC STENOS1S
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References
1. Jozefowicz RF, Griggs RC. Myotonic dystrophy. Neurol Clin 1988;6:455-72. 2. Brook JD, McCurrach ME, Harley HG, et al. Molecular basis of myotonic dystrophy: expansion of a trinucleotide (CTG) repeat at the 3' end of a transcript encoding a protein kinase family member. Cell 1992;68:799-808. 3. Aldridge LM. Anaesthetic problems in myotonic dystrophy. Br J Anaesth 1985;57:1119-30. 4. O'Shea PJ. Pre-existing nervous system disorders and the safety of anaesthesia. In: Taylor TH, Major E, eds. Hazards and complication of anaesthesia. Edinburgh: Churchill Livingstone, 1987:52-75. 5. Tanaka M, Tanaka Y. Cardiac anaesthesia in a patient with myotonic dystrophy. Anaesthesia 1991;46:462-5. 6. Durelli L, Mutani IL Fassio F, Delsedime M. The effects of the increase of arterial potassium upon the excitability of normal and dystrophic myotonic muscles in man. J Neurol Sci 1982; 55:249-57. 7. Kirklin JW, Barratt-Boyes BG, eds. Cardiac surgery. 2nd ed. New York: Churchill Livingstone, 1993:129-65. 8. Buckberg GD, Olinger GN, Mulder DG, Maloney JV Jr. Depressed postoperative cardiac performance. J Thorac Cardiovasc Surg 1975;70:974-88.
Coronary Artery Aneurysm Associated With Adult Supravalvular Aortic Stenosis A h m e t T. Yilmaz, MD, M e h m e t Arslan, MD, Ertu6rul Ozal, MD, H a k a n B~'ng61, MD, H a r u n Tatar, MD, a n d O m e r Yiiksel Ozt/irk, MD Department of Cardiovascular Surgery, Giilhane Military Medical Academy, Ankara, Turkey Two patients, aged 20 and 21 years, with supravalvular aortic stenosis and aneurysms of the coronary arteries are described. In supravalvular aortic stenosis, dilatation of the sinuses of Valsalva and multiple abnormalities of one or both coronary arteries are common. A n e u r y s m of coronary artery has not been well recognized as a lesion associated with supravalvular aortic stenosis. The operation in these patients was limited to relief of the supravalvular obstruction.
(Ann Thorac Surg 1996;62:1205-7) n congenital supravalvular aortic stenosis, coronary artery a b n o r m a l i t y is one of the major associated cardiovascular lesions. The coronary arteries m a y be dilated a n d tortuous because the ostia are b e l o w the site of obstruction a n d e x p o s e d to elevated left ventricular pressure, or they m a y b e c o m e n a r r o w e d by the overhanging, stenosing ring or even c o m p l e t e l y obstructed should the valve cusp b e c o m e a d h e r e n t to the aortic wall [1]. The majority of these a n o m a l i e s are obstructing
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Accepted for publication April 25, 1996. Address reprint requests to Dr Yilrnaz, GATA Loj Numan Apt No. 5, 06018 Etlik, Ankara, Turkey. 0003-4975196/$15.00 PII S0003-4975(96)00383-9