Kenichi Kurosaki

Prevalence of Arrhythmias and Their Risk Factors Mid- and Long-Term After the Arterial Switch Operation

Early results of the arterial switch operation (ASO) for transposition of the great arteries (TGA) are good, but there are few mid- and long-term data on postoperative arrhythmias, especially in Japan. In this study, clinical data on 624 1-year survivors who had an ASO between 1976 and 1995 were collected from six institutes in Japan up to October 2002. Sixty (9.6%) 1-year survivors had significant arrhythmias. Bradycardia occurred in 22 patients, including complete atrioventricular block (CAVB) in 12, sick sinus syndrome (SSS) in 6, and second-degree atrioventricular block in 4. Syncope developed in 2 with CAVB and 2 with SSS. Ten patients with bradycardia underwent permanent pacemaker implantation. Supraveutricular tachycardia (SVT) was seen in 25 patients, including paroxysmal supraventricular tachycardia in 16, atrial flutter in 7, and atrial fibrillation in 2. Six patients with SVT received antiarrhythmic medication. SVT was transient in 20 and persistent in 5. Ventricular arrhythmias occurred in 13 patients, including nonsustained ventricular tachycardia in 5, paroxysmal ventricular contractions with couplets in 5, ventricular flutter in 2, and sustained ventricular tachycardia in 1. Four patients with ventricular arrhythmias received antiarrhythmic medication. Of the study patients, 8 died 1 year or more after ASO. Death was directly related to arrhythmia in 1 patient and was due to nonsustained ventricular tachycardia with severe congestive heart failure. The presence of a ventricular septal defect (VSD) was a risk factor for postoperative arrhythmia. Patients with TGA and VSD had more arrhythmias than those with TGA and an intact ventricular septum (13.7 vs 8.7%, p < 0.05), and this was especially true for CAVB (3.9% vs 1.0%, p < 0.05). In 36 patients clearly documented time onset of postoperative arrhythmia arrhythmia developed in 18 (50%) after less than 1 year and in 15 (42%) after more than 5 years. In summary serious arrhythmias after ASO were uncommon, but postoperative arrhythmias, such as unpaced CAVB, SSS, and VT, were related to morbidity and mortality. VSD was a risk factor for postoperative arrhythmia, especially CAVB. Approximately half of the arrhythmias developed late. Lifelong monitoring with respect to arrhythmia is needed for patients after ASO.

Acute Coronary Artery Dilation Due to Kawasaki Disease and Subsequent Late Calcification as Detected by Electron Beam Computed Tomography

We wanted to clarify the relationships between the degree of acute coronary artery dilation caused by Kawasaki disease and subsequent late calcification. Electron beam computed tomography (EBCT) was used to study 79 patients who had previously undergone selective coronary angiograms less than 100 days after the onset of Kawasaki disease. The EBCT was performed using an Imatron C-150 with a 100-ms exposure time and consecutive images at 6-mm intervals. The interval from the onset of Kawasaki disease to EBCT ranged from 2 to 242 months (median, 103 months). The maximum diameters of the right coronary, the left anterior descending, and the left circumflex arteries, as well as the bifurcation of the left coronary artery were measured in the initial coronary angiograms. A total of 250 branches, including 53 left coronary arteries, were measured, and the relationship between the degree of the initial coronary artery dilation and subsequent calcification in the branches and left coronary artery was analyzed. The coronary arterial diameter of all branches that eventually calcified was 6 mm or greater. The incidence of calcification in branches measuring 6 mm or greater on the initial coronary angiogram was 12% at 5 years, 44% at 10 years, and 94% at 20 years (n = 141). Dilation greater than 6 mm is associated with a high probability of late calcification.

Two Young Adults Who Had Acute Coronary Syndrome after Regression of Coronary Aneurysms Caused by Kawasaki Disease in Infancy

We report two young adult patients who had acute coronary syndrome after regression of coronary aneurysms caused by Kawasaki disease (KD). A 26 year-old man had acute anterior myocardial infarction at midnight after drinking alcohol. He had had bilateral coronary aneurysms caused by KD at the age of 8 months. Selective coronary angiograms (CAGs) at the age of 7 years revealed regression of both coronary aneurysms. He had no symptoms until the onset of acute myocardial infarction. The other patient was a 24 year-old man diagnosed as having a subendocardial infarction. He had had bilateral coronary aneurysms caused by KD at the age of 1 year. CAGs at the age of 9 years showed that both had regressed. It should be recognized that young adults with apparently normal coronary arteries angiographically after regression of large coronary aneurysms caused by KD may occasionally have acute coronary syndromes. We suspect intimal involvement of the coronary arterial wall after regression of the large aneurysms underlies the acute coronary syndrome in adults. Risk factors for atherosclerosis must be avoided in this population.

Anatomic Repair for Corrected Transposition With Left Ventricular Outflow Tract Obstruction

BACKGROUND We investigated the long-term outcomes of anatomic repair for congenitally corrected transposition of great arteries (ccTGA) and its variant associated with left ventricular outflow tract obstruction (LVOTO) and ventricular septal defect (VSD). METHODS From 1987 to 2011, 47 patients (27 with pulmonary atresia and 20 with pulmonary stenosis) with ccTGA and its variant associated with LVOTO and VSD underwent anatomic repair. The mean operative age was 5.5 ± 3.7 years old (range, 1.6 to 21.3). The preoperative right ventricular end-diastolic volume was 133% ± 31% (81 to 222) of their normal size. The atrial switch procedure was Mustard in 31 patients and Senning in 16, with the latter used in all from 2002. RESULTS The mean follow-up period was 11.6 ± 7.3 years (maximum, 22.7). The VSD was concomitantly enlarged in 4 patients and Damus-Kaye-Stansel (DKS) anastomosis was added in 9 patients with pulmonary stenosis and restrictive VSD. The overall survival rate at 20 years was 70.2% and no mortality has been observed in 21 consecutive patients since 1997. No patient required reoperation for the postoperative systemic ventricular outflow tract obstruction. A surgical heart block developed in 1 patient (2.1%) who underwent concomitant VSD enlargement. None of the patients developed a moderate or greater aortic or neo-aortic regurgitation. CONCLUSIONS Recent outcomes after anatomic repair for congenitally corrected transposition of great arteries associated with LVOTO and VSD were excellent. For patients with pulmonary stenosis and restrictive VSD, additional DKS anastomosis seems to be an effective approach to avoid postoperative systemic ventricular outflow tract obstruction and surgical heart block.

Long-term results of treatments for functional single ventricle associated with extracardiac type total anomalous pulmonary venous connection

OBJECTIVES Surgical outcomes of patients with functional single ventricle have improved, though those for patients whose condition is complicated by extracardiac type total anomalous pulmonary venous connection (TAPVC) remain poor. We retrospectively reviewed our 21 years of surgical experiences with this challenging group. METHODS From 1990 to 2010, 48 consecutive patients with functional single ventricle complicated by extracardiac TAPVC (26 males, 46 with right atrial isomerism) underwent initial surgical palliation at our centre. The median age and body weight at surgery were 69 days and 3.5 kg, respectively. The type of TAPVC was supracardiac in 31 patients, infracardiac in 14 and mixed type in 3. TAPVC was repaired in 25 patients before bidirectional Glenn (BDG) and 18 at BDG, while it remained in 3 patients. Since 2007, stent implantation for obstructive drainage veins for patients with preoperative pulmonary venous obstruction and sutureless marsupialization for relief of postoperative pulmonary venous stenosis (PVS) have been initiated. The mean follow-up period was 4.2 ± 5.1 years. RESULTS The overall survival rates at 1, 3 and 5 years after the initial surgical intervention were 58.3, 41.1 and 31.3%, respectively. Sixteen patients achieved the Fontan operation (33.3%). The freedom from postoperative PVS rates at 1 and 3 years after repair was 68.7 and 63.4%, respectively. Univariate analysis detected that infracardiac TAPVC (P = 0.036), coexisting major aortopulmonary collaterals (P = 0.017), and TAPVC repair before BDG (P = 0.036) all reduced survival, and multivariable analysis indicated the repair of TAPVC before BDG as the only risk factor (P = 0.032). Whereas the occurrence of postoperative PVS did not reduce survival, which had a significant negative impact on achieving the Fontan operation (P = 0.008). The cumulative survival rate did not improve by surgical era. CONCLUSIONS Surgical outcomes of patients with functional single ventricle undergoing the repair of extracardiac TAPVC in the neonatal period due to obstruction of the venous drainage pathway remain poor. Stent implantation for obstructive drainage veins to delay the timing of surgical correction and sutureless marsupialization as relief of postoperative PVS are expected to improve the late outcomes; however, the effect is still limited.

Long-Term Results of Mitral Valve Repair for Severe Mitral Regurgitation in Infants: Fate of Artificial Chordae

BACKGROUND The experience with mitral valve repair for severe mitral regurgitation in infants was retrospectively reviewed. METHODS From 1978 to 2009, 15 infant patients (4 boys, 7.2±3.2 months old) underwent mitral valve repair for severe mitral regurgitation. The etiology of mitral regurgitation according to Carpentier classification was type I in 1 patient, type II in 10 patients, and type III in 4 patients. Artificial chordal replacement was performed in 11 patients. The follow-up course was completed in all patients, with a median follow-up period of 10.2 years (range, 2.2 to 33.4 years). RESULTS There were no operative or in-hospital mortalities. The actuarial survival and freedom from reoperation rates at 10 years were 89% and 65%, respectively. Five patients required redo mitral valve surgery, including 4 patients needing mitral valve replacement. Three of 4 patients with type III mitral regurgitation, caused by congenital subvalvar structural abnormality, required redo mitral valve surgery. In 11 patients who underwent artificial chordal reconstruction, 2 (18%) required mitral valve replacement during the early postoperative period, whereas the remaining patients showed no recurrent mitral regurgitation during the entire study period. The latest echocardiography findings at 7.3 years after the operation showed that the left ventricular diastolic diameter, mitral valve diameter, and ejection fraction were 99.2%±5.0% of normal, 101.7%±13.3% of normal, and 0.741±0.058, respectively. CONCLUSIONS Long-term durability of mitral valve repair for severe mitral regurgitation in infants was satisfactory. Artificial chordal reconstruction is an effective procedure without an elevated risk of late reoperation.

Long-term outcomes of common atrioventricular valve plasty in patients with functional single ventricle

OBJECTIVES Common atrioventricular valve (CAVV) regurgitation is widely known as a risk factor for mortality and Fontan completion in patients with functional single ventricle. Hence, we reviewed our surgical experience with CAVV plasty in Fontan candidates. METHODS Staged Fontan strategy and extracardiac total cavopulmonary connection as Fontan modification were our principal approaches in 1995. Since then, 38 consecutive Fontan candidates (21 males, median weight at operation was 7.0 kg and median age was 17 months old) underwent CAVV plasty. Right atrial isomerism was associated with 24 patients. The initial CAVV plasty was performed before inter-stage bidirectional Glenn (BDG) in 3 patients, at BDG in 23, before Fontan in 4 and during Fontan in 8. Since 1995, the modified Alfieri technique with a tailed, expanded, polytetrafluoroethylene tube as a bridging strip was the procedure for repair and 27 patients underwent the procedure. The mean follow-up period was 7.1 years (range 0-17 years). RESULTS Actuarial survival and freedom from CAVV replacement rates at 1, 5 and 10 years were 81, 70 and 67% and 89, 85 and 75%, respectively. Seven patients ultimately underwent CAVV replacement with one death. Twenty-three of the 38 patients completed Fontan operation (61%). Association with total anomalous pulmonary venous connection (P= 0.01) and CAVV plasty before BDG (P= 0.05) were risk factors for mortality. CONCLUSIONS CAVV plasty for patients with functional single ventricle is still challenging; however, the aggressive and repeated surgical intervention may contribute to provide better life-prognosis. The ventricular volume unloading effect of BDG without additional pulmonary blood flow or Fontan operation did not contribute to maintain CAVV function. Therefore, there would not be any hesitation for CAVV replacement to control CAVVR in the setting of systemic ventricular failure. Although the statistically significant therapeutic superiority of the modified Alfieri technique was not shown so far, further follow-up may reveal the advantage of this easy and simple technique.

Late Clinical Features of Patients With Pulmonary Atresia or Critical Pulmonary Stenosis With Intact Ventricular Septum After Biventricular Repair

BACKGROUND We aimed to reveal late clinical features of patients with pulmonary atresia with intact ventricular septum (PA/IVS) or critical pulmonary stenosis (cPS) after biventricular repair (BVR) based on preoperative right ventricular (RV) end-diastolic volume (RVEDV) findings. METHODS Since 1985, 23 of 73 patients with PA/IVS (n=22) or cPS (n=1) with a tripartite RV and without major sinusoidal communication underwent BVR with a hybrid approach. The mean age and weight at BVR were 1.4±2.1 years and 6.9±5.9 kg, respectively. Mean follow-up was 10.1±6.4 years (range, 1.1 to 24.6 years). RESULTS Overall survival, reintervention-free, and arrhythmia-free rates at 20 years were 90.6%, 75.4%, and 50.4%, respectively. In 19 patients with preoperative RVEDV of 60% to 120% of normal, echocardiography at 10 years after BVR showed well-maintained RV systolic function. However, RV volume was quantitatively dilated in 16 (88.9%) due to moderate or greater tricuspid regurgitation in 8 (44.4%), pulmonary regurgitation in 12 (66.7%), or both, which caused arrhythmia in 3 patients more than 10 years after BVR. Two patients with preoperative RVEDV of greater than 120% of normal required tricuspid valve replacement after BVR, after which refractory atrial tachyarrhythmia developed in both patients. Furthermore, 2 patients with preoperative RVEDV of less than 60% of normal showed a cardiac index value within 2.5 L/min/m2 at 1 year after BVR, which did not improve. CONCLUSIONS Patients with PA/IVS or cPS and adequately sized RV showed good late clinical features after BVR. However, long-term follow-up examinations are necessary for RV dilatation and late-onset arrhythmia.

Long-term outcomes after definitive repair for tetralogy of Fallot with preservation of the pulmonary valve annulus

OBJECTIVES The aim of our study was to evaluate the long-term outcomes after definitive repair of tetralogy of Fallot with preservation of the pulmonary valve (PV) annulus. METHODS From 1989 to 2000, 84 of 222 patients (37.8%) with tetralogy of Fallot and PV stenosis underwent definitive repair with preservation of the PV annulus without right ventriculotomy. PV commissurotomy was concomitantly performed in 74 patients (88.1%). The PV was bicuspid in 56 patients (66.7%); the mean Z value was -1.2 ± 1.5 (range, -4.9 to 2.4). The mean follow-up period was 15.8 ± 5.7 years (maximum, 22.8), and follow-up data were complete for 75 patients (89.3%). RESULTS The actuarial survival and freedom from reoperation rates at 20 years was 98.6% and 95.8%. The freedom from ventricular arrhythmia at 5, 10, 15, and 20 years was 98.7%, 89.6%, 74.1%, and 58.0%, respectively. All detected ventricular arrhythmias were isolated monofocal premature ventricular contractions. Freedom from moderate or greater pulmonary regurgitation at 5, 10, 15 and 20 years was 50.4%, 44.9%, 38.4%, and 35.7%, respectively. A bicuspid PV (hazard ratio, 2.910; 95% confidence interval, 1.404-6.204, P = .004) and a Z-value of less than -2 (hazard ratio, 1.948; 95% confidence interval, 0.915-5.857; P = .034) were the risk factors for developing moderate or greater pulmonary regurgitation. CONCLUSIONS The long-term outcomes after definitive repair of tetralogy of Fallot with preservation of the PV annulus were excellent. Although isolated, monofocal premature ventricular contractions were frequently observed, fatal ventricular arrhythmia was not. The indication should not only be decided by the PV annulus size, but also by the valvular morphology to maintain long-term PV competency.

Acute Rupture of Chordae Tendineae of the Mitral Valve in Infants A Nationwide Survey in Japan Exploring a New Syndrome

Background— Recently, infant cases of acute heart failure attributable to rupture of the mitral chordae tendineae have been reported. However, little is known about the pathogenesis and clinical course of this condition. Methods and Results— Ninety-five children with rupture of mitral chordae tendineae were identified in nationwide surveys of Japan diagnosed from 1995 to 2013. The clinical manifestations, management strategies, and prognosis were investigated. Eighty-one (85%) patients were between 4 and 6 months (median, 5 months) of age. In 63 (66%) patients, rupture occurred during the spring or summer. The underlying conditions before rupture included Kawasaki disease (10 cases), maternally derived anti-SSA antibodies (2 cases), and infective endocarditis (1 case). Surgery was performed in 80 patients (94 operations), and the final operations included plasty of mitral chordae in 52 cases and mechanical valve replacement in 26 cases. The histopathologic examinations of the mitral valves and chordae (n=28) revealed inflammatory reactions with predominant mononuclear cell infiltration in 18 cases (64%) and increased fibrous and myxoid tissue in 11 cases (39%), suggesting that nonbacterial infectious or autoimmune endocarditis and myxoid changes are involved in the pathogenesis. Eight patients (8.4%) died before (n=6) and shortly after (n=2) the operation, and significant neurological complications persisted in 10 cases (11%). Conclusions— Acute heart failure attributable to rupture of the mitral chordae tendineae in infants is a unique disease resulting from diverse causes. This condition should be recognized as a significant cardiovascular disorder that may cause sudden onset of cardiogenic shock and death in infants.Background— Recently, infant cases of acute heart failure attributable to rupture of the mitral chordae tendineae have been reported. However, little is known about the pathogenesis and clinical course of this condition. Methods and Results— Ninety-five children with rupture of mitral chordae tendineae were identified in nationwide surveys of Japan diagnosed from 1995 to 2013. The clinical manifestations, management strategies, and prognosis were investigated. Eighty-one (85%) patients were between 4 and 6 months (median, 5 months) of age. In 63 (66%) patients, rupture occurred during the spring or summer. The underlying conditions before rupture included Kawasaki disease (10 cases), maternally derived anti-SSA antibodies (2 cases), and infective endocarditis (1 case). Surgery was performed in 80 patients (94 operations), and the final operations included plasty of mitral chordae in 52 cases and mechanical valve replacement in 26 cases. The histopathologic examinations of the mitral valves and chordae (n=28) revealed inflammatory reactions with predominant mononuclear cell infiltration in 18 cases (64%) and increased fibrous and myxoid tissue in 11 cases (39%), suggesting that nonbacterial infectious or autoimmune endocarditis and myxoid changes are involved in the pathogenesis. Eight patients (8.4%) died before (n=6) and shortly after (n=2) the operation, and significant neurological complications persisted in 10 cases (11%). Conclusions— Acute heart failure attributable to rupture of the mitral chordae tendineae in infants is a unique disease resulting from diverse causes. This condition should be recognized as a significant cardiovascular disorder that may cause sudden onset of cardiogenic shock and death in infants. # CLINICAL PERSPECTIVE {#article-title-39}