Pericardial tamponade due to erosion of a Figulla Flex II device after closure of an atrial septal defect.

We present a case of an 8-year-old boy suffering from sudden-onset severe chest pain and cardiogenic shock due to cardiac tamponade caused by erosion of a Figulla Flex II device. His symptoms developed 4 days after transcatheter closure of an atrial septal defect. After emergent pericardiocentesis, surgery was performed to remove the device, close the atrial septal defect, and repair the laceration in the anterior-superior wall of the right atrium and the perforation on the aortic wall adjacent to the right atrial free wall perforation site. All surgical procedures were successful, and the patient was discharged without sequelae. Although there have been few reports on the erosion of this flexible device, a lethal complication can occur when the right-sided disc of the oversized device impinges perpendicularly on the aortic wall.

Risk factors of non-sustained ventricular tachycardia by technetium-perfusion imaging in patients with coronary artery lesions caused by Kawasaki disease.

BACKGROUND: Sudden death can occur in some patients with non-sustained ventricular tachycardia (NSVT) after myocardial infarction (MI) in those with coronary artery lesions (CAL) caused by Kawasaki disease (KD). The aim of this study was to determine the risk factors for NSVT in the late period after KD by technetium-99m-tetrofosmin myocardial perfusion imaging (MPI). METHODS: We retrospectively analyzed the relation between the appearance of NSVT and the findings in MPI single-photon-emission computed tomography (SPECT) in 75 patients (55 males and 20 females) who had had CAL caused by KD. All the patients had undergone MPI and 24-h Holter electrocardiogram at the same time between 2003 and 2012. The age at MPI ranged from 2 to 44 years (median 19 years), and the time from the onset of KD to MPI ranged from 1 to 44 years (median 18 years). We evaluated extent score (ES), summed rest score (SRS), summed stress score (SSS), summed difference score (SDS), and left ventricular ejection fraction (LVEF) by quantitative gated SPECT software. We analyzed which factors related to NSVT using multivariate logistic regression. Further, we calculated the cut-off point for NSVT using receiver operating characteristic curve. RESULTS: The affecting factors were ES (OR, 0.63, 95%CI, 0.35-0.92, p=0.013) and the interval from the onset of KD to MPI (OR, 0.82, 95%CI, 0.69-0.96, p=0.004). The cut-off points for ES and the interval from the onset of KD were 11% (AUC, 0.931, p<0.001) and 18 years (AUC, 0.732, p=0.007), respectively. CONCLUSIONS: ES is the strongest parameter for predicting NSVT in the late period. In patients with post-KD, adolescence and young adults with ES ≥11% are at risk of fatal ventricular arrhythmia.

Clinical and Echocardiographic Impact of Tafazzin Variants on Dilated Cardiomyopathy Phenotype in Left Ventricular Non-Compaction Patients in Early Infancy.

BACKGROUND: Left ventricular non-compaction (LVNC) is a cardiomyopathy morphologically characterized by 2-layered myocardium and numerous prominent trabeculations, and is often associated with dilated cardiomyopathy (DCM). Variants in the gene encoding tafazzin (TAZ) may change mitochondrial function and cause dysfunction of many organs, but they also contribute to the DCM phenotype in LVNC, and the clinical and echocardiographic features of children with this phenotype are poorly understood. Methods and Results: We enrolled 92 DCM phenotype LVNC patients and performed next-generation sequencing to identify the genetic etiology. Ten TAZ variants were identified in 15 male patients (16.3%) of the 92 patients, including 3 novel missense substitutions. The patients with TAZ variants had a higher frequency of early onset of disease (92.3% vs. 62.3%, P=0.0182), positive family history (73.3% vs. 20.8%, P=0.0001), and higher LV posterior wall thickness Z-score (8.55±2.60 vs. 5.81±2.56, P=0.0103) than those without TAZ variants, although the mortality of both groups was similar. CONCLUSIONS: This study provides new insight into the impact of DCM phenotype LVNC and emphasizes the clinical advantages available for LVNC patients with TAZ variants.

Left ventricular reverse remodeling with infantile dilated cardiomyopathy and pitfalls of carvedilol therapy.

BACKGROUND: The left ventricular reverse remodeling (LVRR) in idiopathic dilated cardiomyopathy (DCM) and the treatment with carvedilol in infants with severe heart failure remain poorly understood. METHODS: We reviewed the medical records of 5 infants around 12 months old referred to our hospital with severe heart failure due to DCM. Increased left ventricular fractional shortening (LVFS) by more than 10% and the percent of normal of left ventricular end-diastolic dimension (%LVDd) less than 120% were defined as LVRR in this study. RESULTS: DCM onset ranged from 8 to 16 months. Initial treatment of their acute heart failure was successful in all 5 but 4 patients relapsed despite the usual dose of carvedilol (induction 0.02-maintenance 0.4mg/kg/day), and developed worsening heart failure. Brain natriuretic peptide (BNP) levels which increased again after the acute treatment had fallen subsequent to discontinuing or decreasing carvedilol. Over 24 months, LVFS had increased from 11±2% (mean±SD) to 34±5% (p<0.05), and %LVDd decreased from 149±27% to 108±11% (p<0.05). CONCLUSIONS: LVRR was found at 2 years after the onset of DCM. Usual dose induction of carvedilol therapy can sometimes worsen heart failure after successful initial conventional treatment for the acute heart failure in DCM. Close control of carvedilol treatment may determine the prognosis of infantile DCM around 12 months old. It is prudent to increase low-dose carvedilol slowly corresponding with the BNP level.

Heterogeneity of Ventricular Sympathetic Nervous Activity is Associated with Clinically Relevant Ventricular Arrhythmia in Postoperative Patients with Tetralogy of Fallot.

This study aimed to clarify whether there is an association between ventricular sympathetic nervous activity (SNA) and clinically relevant ventricular arrhythmia (a run of ≥ 3 consecutive ventricular beats, RVA) in postoperative patients with tetralogy of Fallot (TOF). We performed a retrospective study in a national referral center of pediatric cardiology in Japan. Twenty-four postoperative TOF patients (13 males, median age 17 years) undergoing myocardial (123)I metaiodobenzylguanidine (MIBG) scintigraphy were included. We measured the heart-to-mediastinum ratio (HMR) and washout ratio (WR) from planar MIBG myocardial scintigraphy. Tomographic images and polar maps were generated with 20 segments. The standard deviation of percentage uptake of 20 segments (SD-uptake) as an index of heterogeneous MIBG uptake to the ventricular myocardium was calculated. We compared these MIBG-derived variables with the patients' clinical profiles, including ECG findings and hemodynamics. Eight of 24 patients had RVA (RVA group), and the other 16 did not have RVA (non-RVA group). There were no significant differences in the HMR (1.9 ± 0.5 vs. 2.2 ± 0.4) and WR (50 ± 5 vs. 42 ± 10) between the two groups. SD-uptake was significantly higher in the RVA group than in the non-RVA group (15 ± 3 vs. 12 ± 3, p = 0.03). QT dispersion (ms) was also higher in the RVA group than in the non-RVA group (53 ± 23 vs. 44 ± 18, p = 0.04). Multivariate logistic regression showed that SD-uptake and QT dispersion were independent predictors in the RVA group (p = 0.02, p = 0.03). In addition to greater QT dispersion, heterogeneous SNA is associated with RVA in TOF patients postoperatively.

Efficacy and safety of percutaneous transluminal balloon dilation to prevent progression of banding site stenosis after bilateral pulmonary artery banding.

OBJECTIVES: To investigate the efficacy and safety of percutaneous transluminal balloon dilation (PTBD) for the treatment of bilateral pulmonary artery banding (bil-PAB) site stenosis. BACKGROUND: Although bil-PAB is an alternative initial treatment for high-risk neonates with hypoplastic left heart syndrome (HLHS) or critical aortic stenosis (cAS), those patients often suffer from desaturation because of progressive stenosis of the bil-PAB sites during the interstage period. METHODS: We retrospectively evaluated the efficacy and safety of 11 consecutive PTBD procedures performed between 2006 and 2012 to treat bil-PAB site stenosis in four high-risk infants (three females) with HLHS or cAS. RESULTS: PTBD was repeated twice in two patients and three times in one patient over intervals. The mean balloon diameter (BD) and BD-to-band circumference (BC) ratio were 3.1 ± 0.5 mm and 0.31 ± 0.06, respectively. After the procedures, the mean minimum lumen diameter was dilated significantly from 1.1 ± 0.1 mm to 1.7 ± 0.3 mm (P < 0.01), and the mean peripheral oxygen saturation increased significantly from 75 ± 8% to 85 ± 4% (P < 0.01). All patients reached the next stage operation involving the Norwood & bidirectional Glenn or Ross procedure, after growth. No complications such as band rupture occurred. CONCLUSIONS: For progressive stenosis of bil-PAB sites, PTBD using a balloon size that did not exceed the BC (BD around 30% of the BC) was an effective and safe procedure.

Evaluation of Valsalva sinus wall deformation due to compression by the Amplatzer septal occluder and the potential for erosion development.

OBJECTIVES: We studied whether the pressure exerted by the Amplatzer septal occluder (ASO) disk on the Valsalva sinus wall (VW) is a risk factor for erosion and attempted to determine the pressure that may trigger erosion. BACKGROUND: The causes and mechanisms of erosion after ASO placement remain unclear. METHODS: We reviewed 665 consecutive patients with atrial septal defects who underwent ASO closure at our hospital from 2005 to 2012. We used transesophageal echocardiography and other tests to evaluate disk-related VW deformation as a risk factor for erosion. RESULTS: Immediately after ASO placement, intermittent VW deformation from either disk was determined in 54 of the 665 patients (8%). Of these 54 patients, only 1 exhibited late erosion (0.15%) during a follow-up of more than 4 years (0.035% a year). The maximum VW deformation depth relative to the standard curve, or dent, was 2.6 mm in this patient, whereas that in the remaining patients ranged from 0.5 to 2.0 mm. The dent values were significantly deeper in patients with contact between the left atrial disk and posterior atrial wall than in those without contact (P = 0.03). There was a significant negative correlation between dent and the aortic side-maximum device thickness (DT)/middle part-DT ratio (P = 0.04). CONCLUSION: Although VW deformation, particularly deep VW deformation caused by pressure from either disk after ASO placement must be a recognized risk for erosion, which deformation level carries a stronger risk for erosion could not be concluded.

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.

Clinical characteristics and long-term outcome of acute myocarditis in children.

The clinical course of acute myocarditis (AM) in children varies from being asymptomatic to causing sudden cardiac death. The aim of this study was to clarify the clinical characteristics and the long-term outcome of AM in children. We enrolled 24 children (aged from 0.1 to 14.6 years, median 8.4 years), who were diagnosed as AM between 1978 and 2010. The maximum follow-up period was 31 years (median 7 years). We retrospectively investigated their clinical course of AM. We also analyzed survival rate, persistence of decreased left ventricular ejection fraction (LVEF) by two-dimensional echocardiogram (2DE), and persistence of complete atrioventricular block (CAVB) by the Kaplan-Meier method. Furthermore, using univariate analysis we analyzed the factors that influenced the outcome. The survival rate was 86 % (95 % confidence interval (CI), 65-96) at 30 years. The persistence rate of LVEF less than 60 % at 1 month, 1 years, and 3 years was 44 % (95 % CI, 22-68), 36 % (95 % CI, 17-62) and 18 % (95 % CI, 3-59), respectively (n = 16), and the persistence of CAVB at 10 days was 36 % (95 % CI, 14-66, n = 11). In six patients with persistence of wide QRS (>100 ms), there were one acute death, two late deaths, and one orthotopic heart transplantation. The 30-year survival rate for six patients with wide QRS and 17 patients without wide QRS in the late phase was 50 % (95 % CI, 17-83) and 100 % (P = 0.0078), respectively. The factors in the acute phase influenced on the outcome were log creatine phosphokinase (CPK) 4.60 (95 % CI, 1.64-29.26, P = 0.001), appearance of ventricular tachycardia 19.71 (95 % CI, 2.50-399.9, P = 0.005), and LVEF 0.91 (95 % CI, 0.81-0.98, P = 0.015), respectively. The predictors of poor outcome in children with AM were high serum CPK, appearance of ventricular tachycardia and low LVEF in the acute phase, and persistence of wide QRS in the late phase. The long-term survival rate of children without these factors was fair.

Prevalence and distribution of sarcomeric gene mutations in Japanese patients with familial hypertrophic cardiomyopathy.

BACKGROUND: Hypertrophic cardiomyopathy (HCM), which is inherited as an autosomal dominant trait, is the most prevalent hereditary cardiac disease. Although there are several reports on the systematic screening of mutations in the disease-causing genes in European and American populations, only limited information is available for Asian populations, including Japanese. METHODS AND RESULTS: Genetic screening of disease-associated mutations in 8 genes for sarcomeric proteins, MYH7, MYBPC3, MYL2, MYL3, TNNT2, TNNI3, TPM1, and ACTC, was performed by direct sequencing in 112 unrelated Japanese proband patients with familial HCM; 37 different mutations, including 13 novel ones in 5 genes, MYH7, MYBPC3, TNNT2, TNNI3, and TPM1, were identified in 49 (43.8%) patients. Among them, 3 carried compound heterozygous mutations in MYBPC3 or TNNT2. The frequency of patients carrying the MYBPC3, MYH7, and TNNT2 mutations were 19.6%, 10.7%, and 8.9%, respectively, and the most frequently affected genes in the northeastern and southwestern parts of Japan were MYBPC3 and MYH7, respectively. Several mutations were found in multiple unrelated proband patients, for which the geographic distribution suggested founder effects of the mutations. CONCLUSIONS: This study demonstrated the frequency and distribution of mutations in a large cohort of familial HCM in Japan.

The 30-year outcome for patients after myocardial infarction due to coronary artery lesions caused by Kawasaki disease.

This study determined the long-term outcome for patients after myocardial infarction (MI) due to Kawasaki disease (KD). Retrospective analysis was performed for 60 patients who had experienced MI between 1976 and 2007. Their ages at the initial MI ranged from 3 months to 33 years (median, 2 years). The maximum follow-up period after the initial MI was 33 years (median, 16 years). Coronary angiography, left ventriculography, and radioisotope myocardial perfusion imaging (MPI) had been performed for 56 patients more than 2 months after MI when all were in stable condition. The survival rate and ventricular tachycardia (VT)-free survival rate were calculated after the initial MI by the Kaplan-Meier method. Both sustained and nonsustained VT were included. Furthermore, the Cox proportional hazards model was used to analyze which factors influenced the post-MI outcome and which influenced the appearance of VT. The 30-year survival rate was 62.7% (95% confidence interval [CI], 44.6-77.9%), and the 25-year VT-free survival rate after MI was 28.5% (95% CI 15.4-46.5%). The postinfarction left ventricular ejection fraction (LVEF) was related to the outcome in this population (hazard ratio 0.86; 95% CI 0.75-0.95; P = 0.002), whereas the development of VT was related to the post-LVEF and to perfusion abnormalities in MPI (P = 0.0002). The 30-year survival rate after MI was poor for the patients with a low LVEF. With aging, the existence of nonviable myocardium in the infarct area can induce fatal ventricular arrhythmia more than 10 years after the original MI.

Acute coronary syndrome in adult patients with coronary artery lesions caused by Kawasaki disease: review of case reports.

Information about acute coronary syndrome caused by Kawasaki disease-related coronary artery lesions in adults is sketchy. We reviewed the clinical features of 50 adult patients who had an acute coronary syndrome caused by coronary artery lesions due to Kawasaki disease or probable Kawasaki disease from 1980 to 2008. Of the 50 patients, 43 (90%) were male and seven were female (10%). Their ages at the onset of acute coronary syndrome ranged from 18 to 69 years, with a median of 28 years. The culprit lesion in 43 patients was thrombotic occlusion of an aneurysm, and 40 patients had giant aneurysms. In the three patients in whom no aneurysms were seen in coronary angiograms performed at the time of acute myocardial infarction, either giant aneurysms or aneurysms had been visualised in childhood. The initial treatment of acute coronary syndrome was as follows: intracoronary thrombolysis, 11; primary percutaneous coronary intervention, 9; emergency coronary artery bypass grafting, 3; and medication, 26. Elective coronary artery bypass grafting was performed in 15 patients. Three patients (6%) died. Of the 27 patients with additional coronary risk factors, 20 were smokers. Giant aneurysms due to Kawasaki disease continued to cause acute coronary syndrome in adult life with onset at a younger age than typifies that due to atherosclerosis in the general population, especially in male population rather than female population. Even when giant aneurysms regressed after the acute phase, a few patients still developed acute coronary syndrome in adult life. Smoking appears to be the most prominent additional risk factor.