Ser194Leu DSG2 mutation, associated with arrhythmogenic left ventricular cardiomyopathy and ventricular tachycardia.

INTRODUCTION: Arrhythmogenic cardiomyopathy (AC) is an inherited cardiomyopathy characterized by fibro-fatty replacement of cardiomyocytes, leading to life-threatening ventricular arrhythmia and heart failure. Pathogenic variants of desmoglein2 gene (DSG2) have been reported as genetic etiologies of AC. In contrast, many reported DSG2 variants are benign or variants of uncertain significance. Correct genetic variant classification is crucial for determining the best medical therapy for the patient and family members. METHODS: Pathogenicity of the DSG2 Ser194Leu variant that was identified by whole exome sequencing in a patient, who presented with ventricular tachycardia and was diagnosed with AC, was investigated by electron microscopy and immunohistochemical staining of endomyocardial biopsy sample. RESULTS: Electron microscopy demonstrated a widened gap in the adhering junction and a less well-organized intercalated disk region in the mutated cardiomyocytes compared to the control. Immunohistochemical staining in the proband diagnosed with AC showed reduced expression of desmoglein 2 and connexin 43 and intercalated disc distortion. Reduced expression of DSG2 and Connexin 43 were observed in cellular cytoplasm and gap junctions. Additionally, we detected perinuclear accumulation of DSG2 and Connexin 43 in the proband sample. CONCLUSION: Ser194Leu is a missense pathogenic mutation of DSG2 gene associated with arrhythmogenic left ventricular cardiomyopathy.

Do quantitative levels of cardiac troponin I implicate on severity of disease in children, adolescences, and young adults with acute myocarditis and myopericarditis?

OBJECTIVES: When cardiac muscle damage occurs, cardiac troponins are released to blood and their detection is used as a marker in clinical setting. The prognostic value of the quantitative levels of blood troponin I in cases of myocarditis and myopericarditis is unclear. The aim of this study was to analyse whether troponin quantitative blood levels can be correlated with the course of hospitalisation and prognosis. METHODS: Retrospective data was collected from all consecutive patients aged ≤30 hospitalised with a diagnosis of acute myocarditis or acute myopericarditis in our health Care Campus between the years 2010-2016. RESULTS: Ninety-three patients with myocarditis and myopericarditis were identified. Higher peak troponin levels correlated with longer hospitalisation times in the cardiac or paediatric wards (p = 0.03, Pearson correlation: r -0.23), and median troponin level at admission correlated with longer overall hospitalisation (p = 0.026, Pearson correlation: r = 0.23). Patients admitted to ICU, received oral cardiac supportive therapy or that were discharged with cardiac drugs had higher median troponin compared to patients who were not but this was not statistically significant. A small group of patients that needed intravenous cardiac support had significantly lower median peak troponin levels (n = 4, 0.375ng/ml, p = 0.048). Only two patients needed extracorporeal membrane oxygenation support, and one died. The small number of patients precludes statistical analysis. CONCLUSION: Higher troponin levels correlated significantly with longer hospitalisation, lower troponin values correlated with intravenous cardiac support, while other variables related to the severity of disease could not be significantly related to higher troponin levels.

Rapid response of a cardiac rhabdomyoma causing severe right ventricular outflow obstruction to Sirolimus in an infant with negative genetics for Tuberous sclerosis.

Mammalian target of rapamycin inhibitors was found recently to be an effective treatment for manifestations of Tuberous sclerosis complex, including cardiac rhabdomyomas. Most cases with Cardiac rhabdomyoma treated with mammalian target of rapamycin inhibitors to date were diagnosed with Tuberous sclerosis. We report a case of cardiac rhabdomyoma and severe right ventricular outflow obstruction in a baby with negative genetics for Tuberous sclerosis that responded rapidly to Sirolimus.

Atypical cardiopulmonary manifestations in pediatric Behçet's disease.

BACKGROUND: Behçet's disease (BD) is a multisystem autoinflammatory disease of unknown etiology. Cardiopulmonary involvement is rare, especially in young patients, and carries high morbidity and mortality rates. AIM: Of 26 patients with pediatric BD enlisted in our center, we encountered three patients with severe atypical cardiorespiratory presentations. Our aim was to describe the manifestations and the course that led to the diagnosis of BD. RESULTS: Three adolescents presented with intracardiac thrombi and left anterior descending obstruction causing myocardial infarction, pulmonary artery aneurysm with pulmonary embolism in situ, and suspected epiglottitis. Two patients had a delayed diagnosis of BD, and all had a good response to anti-inflammatory agents. CONCLUSIONS: This study demonstrated that pediatric BD is associated with atypical cardiopulmonary manifestations which maybe life threatening. Since diagnosis maybe challenging, a high index of suspicion is needed especially in young patients, to promptly diagnose and treat these complications. Cardiopulmonary signs and symptoms, though uncommon, maybe the first manifestation and a clue to the diagnosis of this rare disease.

Rare haematogenous sarcoma metastasis to the heart in a child.

Haematogenous non-contiguous metastatic spread of remote solid tumours to the heart is rare. We describe a previously healthy 5-year-old girl who presented with extensive intracardiac involvement by metastatic pelvic sarcoma.

Specific Therapy Based on the Genotype in a Malignant Form of Long QT3, Carrying the V411M Mutation.

Congenital long QT syndrome (LQTS) is a cardiac channelopathy that leads to the prolongation of the QT interval. This prolongation can lead to ventricular tachyarrhythmia, syncope, and sudden cardiac death. There are various types of LQTS. Treatment of LQT1 and LQT2 is mainly based on antiadrenergic therapy. LQT3, on the other hand, is a result of a mutation of the SCN5A gene, which encodes the sodium channels. In this type, patients are sensitive to vagal stimuli and episodes tend to occur at rest. Sodium channel blocking compounds, such as ranolazine, mexiletine, and flecainide, have been found to be effective in selective mutations.In this case report, we report the case of a child with congenital LQT3 (V411M) who presented first with sudden cardiac death and three weeks later with an implantable cardioverter defibrillator storm. Knowing the specific mutation and understanding the mechanism at the molecular level through an in vitro study yielded a clinically meaningful result. The patient's arrhythmia burden was totally eliminated following successful treatment with flecainide.

Three-step management of a newborn with a giant, highly vascularized, cervical teratoma: a case report.

BACKGROUND: A giant congenital cervical teratoma is often highly vascularized; thus, in addition to a life-threatening airway occlusion at birth it comprises a high risk for significant and lethal blood loss during resection. In the case presented, an endovascular embolization of the carotid artery that supplied a giant congenital cervical teratoma was done as part of a three-stage treatment soon after birth and contributed to an overall good outcome. Embolization in cases of cervical teratomas was not described previously. CASE PRESENTATION: We present a case of a preterm newborn from a Sephardic jewish origin with a giant, highly vascularized, congenital cervical teratoma that was managed successfully in three stages: (1) delivery by an ex utero intrapartum treatment procedure after extensive preoperative planning and followed by tracheostomy, (2) endovascular embolization of the carotid artery that supplied the tumor in order to decrease blood loss during resection, and (3) complete surgical resection. The parents were involved in all the ethical and medical decisions, starting just after the cervical mass was diagnosed prenatally. CONCLUSION: The management of giant congenital cervical teratoma is often challenging from both a medical and ethical prospective. Meticulous perinatal planning and parents' involvement is crucial. Endovascular embolization of the tumor feeding vessels can significantly improve the resection outcome and overall prognosis.

Adding Paracetamol to Ibuprofen for the Treatment of Patent Ductus Arteriosus in Preterm Infants: A Double-Blind, Randomized, Placebo-Controlled Pilot Study.

OBJECTIVE: The objective of this study was to compare the closure rate of hemodynamically significant patent ductus arteriosus (hsPDA) of intravenous ibuprofen + paracetamol (acetaminophen) versus ibuprofen + placebo, in preterm infants of 24 to 316/7 weeks postmenstrual age. STUDY DESIGN: This is a single-center, double-blind, randomized controlled pilot study. Infants were assigned for treatment with either intravenous ibuprofen + paracetamol (n = 12) or ibuprofen + placebo (n = 12). RESULTS: There was no statistical difference in baseline characteristics of the two groups. Echocardiography parameters were comparable before treatment in both groups. There was a trend toward higher hsPDA closure rate in the paracetamol group in comparison to the placebo group (83 vs. 42%, p = 0.08). No adverse effects, clinical or laboratory, were associated with adding paracetamol. CONCLUSION: Our pilot study was unable to detect a beneficial effect by adding intravenous paracetamol to ibuprofen for the treatment of hsPDA. Larger prospective studies are needed to explore the positive tendency suggested by our results and to assure safety.

Patient-Specific Drug Screening Using a Human Induced Pluripotent Stem Cell Model of Catecholaminergic Polymorphic Ventricular Tachycardia Type 2.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia type 2 (CPVT2) results from autosomal recessive CASQ2 mutations, causing abnormal Ca2+-handling and malignant ventricular arrhythmias. We aimed to establish a patient-specific human induced pluripotent stem cell (hiPSC) model of CPVT2 and to use the generated hiPSC-derived cardiomyocytes to gain insights into patient-specific disease mechanism and pharmacotherapy. METHODS AND RESULTS: hiPSC cardiomyocytes were derived from a CPVT2 patient (D307H-CASQ2 mutation) and from healthy controls. Laser-confocal Ca2+ and voltage imaging showed significant Ca2+-transient irregularities, marked arrhythmogenicity manifested by early afterdepolarizations and triggered arrhythmias, and reduced threshold for store overload-induced Ca2+-release events in the CPVT2-hiPSC cardiomyocytes when compared with healthy control cells. Pharmacological studies revealed the prevention of adrenergic-induced arrhythmias by ß-blockers (propranolol and carvedilol), flecainide, and the neuronal sodium-channel blocker riluzole; a direct antiarrhythmic action of carvedilol (independent of its α/ß-adrenergic blocking activity), flecainide, and riluzole; and suppression of abnormal Ca2+ cycling by the ryanodine stabilizer JTV-519 and carvedilol. Mechanistic insights were gained on the different antiarrhythmic actions of the aforementioned drugs, with carvedilol and JTV-519 (but not flecainide or riluzole) acting primarily through sarcoplasmic reticulum stabilization. Finally, comparable outcomes were found between flecainide and labetalol antiarrhythmic effects in vitro and the clinical results in the same patient. CONCLUSIONS: These results demonstrate the ability of hiPSCs cardiomyocytes to recapitulate CPVT2 disease phenotype and drug response in the culture dish, to provide novel insights into disease and drug therapy mechanisms, and potentially to tailor patient-specific drug therapy.

Left Cardiac Sympathetic Denervation in Patients with CASQ2-Associated Catecholaminergic Polymorphic Ventricular Tachycardia.

BACKGROUND: Left cardiac sympathetic denervation (LCSD) was reported to be effective in patients with intractable ryanodine receptor mutation-associated catecholaminergic polymorphic ventricular tachycardia (CPVT). OBJECTIVES: To report our experience with LCSD in calsequestrin (CASQ2) mutation-associated CPVT. METHODS: LCSD was performed in three patients with CASQ2 mutation-associated CPVT with symptoms and exercise-induced ventricular arrhythmia despite high dose beta-blocker RESULTS: None of them experienced symptoms or exercise-induced ventricular arrhythmia after LCSD. However, all had recurrence of symptoms and/or exercise-induced ventricular arrhythmia after 6 months (6-18 months). CONCLUSIONS: LCSD conferred short-term suppression but less than optimal long-term suppression of exercise-induced ventricular arrhythmia among CASQ2-associated CPVT patients.

Clinical Management of Catecholaminergic Polymorphic Ventricular Tachycardia: The Role of Left Cardiac Sympathetic Denervation.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a genetic disorder causing life-threatening arrhythmias whenever sympathetic activity increases. ß-Βlockers are the mainstay of therapy; when they fail, implantable cardioverter-defibrillators (ICDs) are used but often cause multiple shocks. Preliminary results with flecainide appear encouraging. We proposed left cardiac sympathetic denervation (LCSD) as useful additional therapy, but evidence remains anecdotal. METHODS AND RESULTS: We report 63 patients with CPVT who underwent LCSD as secondary (n=54) or primary (n=9) prevention. The median post-LCSD follow-up was 37 months. The 9 asymptomatic patients remained free of major cardiac events. Of the 54 patients with prior major cardiac events either on (n=38) or off (n=16) optimal medical therapy, 13 (24%) had at least 1 recurrence: 0 patients had an aborted cardiac arrest, 2 patients had syncope only, 10 patients had ≥1 appropriate ICD discharges, and 1 patient died suddenly. The 1- and 2-year cumulative event-free survival rates were 87% and 81%. The percentage of patients with major cardiac events despite optimal medical therapy (n=38) was reduced from 100% to 32% (P<0.001) after LCSD, and among 29 patients with a presurgical ICD, the rate of shocks dropped by 93% from 3.6 to 0.6 shocks per person per year (P<0.001). Patients with an incomplete LCSD (n=7) were more likely to experience major cardiac events after LCSD (71% versus 17%; P<0.01) than those with a complete LCSD. CONCLUSIONS: LCSD is an effective antifibrillatory intervention for patients with CPVT. Whenever syncope occurs despite optimal medical therapy, LCSD could be considered the next step rather than an ICD and could complement ICDs in patients with recurrent shocks.

Electrocardiographic comparison of ventricular premature complexes during exercise test in patients with CPVT and healthy subjects.

BACKGROUND: Catecholaminergic polymorphic ventricular tachycardia (CPVT) is a rare but highly malignant inherited arrhythmic disorder. Although a standardized exercise stress test (ST) is the most reliable way to diagnose CPVT, in 30% only single ventricular premature beats (VPCs) were recorded. OBJECTIVE: To evaluate whether electrocardiographic characteristics of VPCs during ST distinguish patients with CPVT from healthy subjects. METHODS: Electrocardiographic characteristics of VPCs during ST in 16 calsequestrin-2 (CASQ2) mutation carriers CPVT patients were compared with that in 36 healthy subjects. RESULTS: CPVT patients had more VPCs (31 ± 14 vs 3 ± 4, P < 0.0001), longer QRS duration (139 ± 18 ms vs 121 ± 21, P = 0.004), and coupling interval (CI; 476 ± 58 ms vs 355 ± 61 ms, P < 0.0001). The most sensitive characteristics for CPVT were >10 VPCs/test (100% sensitivity, 100% negative predictive value [NPV]), left bundle branch block (LBBB) pattern with inferior axis (88% sensitivity, 94% NPV), and CI longer than 400 ms (88% sensitivity, 94% NPV). Bigeminy or trigeminy or LBBB pattern with inferior axis was most specific for CPVT at 100% (100% positive predictive value PPV, 92% NPV). First VPC during the recovery period and VPC recording more than 1 minute during the recovery period were most specific for healthy subjects (100% specificity, 100% PPV). In multivariate analysis, QRS duration >120 ms (odds ratio 4.2, 95% confidence interval 1-17.6, P = 0.04) and first VPC at ≥10 mets (odds ratio 9.1, 95% confidence interval 2.01-41.1, P = 0.004) each predicted the presence of CPVT. CONCLUSIONS: Several electrocardiographic criteria can help distinguish VPCs originating from CPVT compared with healthy subjects.

Mutations in GTPBP3 cause a mitochondrial translation defect associated with hypertrophic cardiomyopathy, lactic acidosis, and encephalopathy.

Respiratory chain deficiencies exhibit a wide variety of clinical phenotypes resulting from defective mitochondrial energy production through oxidative phosphorylation. These defects can be caused by either mutations in the mtDNA or mutations in nuclear genes coding for mitochondrial proteins. The underlying pathomechanisms can affect numerous pathways involved in mitochondrial physiology. By whole-exome and candidate gene sequencing, we identified 11 individuals from 9 families carrying compound heterozygous or homozygous mutations in GTPBP3, encoding the mitochondrial GTP-binding protein 3. Affected individuals from eight out of nine families presented with combined respiratory chain complex deficiencies in skeletal muscle. Mutations in GTPBP3 are associated with a severe mitochondrial translation defect, consistent with the predicted function of the protein in catalyzing the formation of 5-taurinomethyluridine (τm(5)U) in the anticodon wobble position of five mitochondrial tRNAs. All case subjects presented with lactic acidosis and nine developed hypertrophic cardiomyopathy. In contrast to individuals with mutations in MTO1, the protein product of which is predicted to participate in the generation of the same modification, most individuals with GTPBP3 mutations developed neurological symptoms and MRI involvement of thalamus, putamen, and brainstem resembling Leigh syndrome. Our study of a mitochondrial translation disorder points toward the importance of posttranscriptional modification of mitochondrial tRNAs for proper mitochondrial function.

Flecainide therapy suppresses exercise-induced ventricular arrhythmias in patients with CASQ2-associated catecholaminergic polymorphic ventricular tachycardia.

BACKGROUND: Calsequestrin-associated catecholaminergic polymorphic ventricular tachycardia (CPVT2) can cause sudden death in young individuals in response to stress. Beta-blockers are the mainstay medical treatment for patients with CPVT2. However, they do not prevent syncope and sudden death in all patients. Flecainide was reported to reduce exercise-induced ventricular arrhythmias (EIVA) in patients with ryanodine receptor-associated CPVT. The role of flecainide in CPVT2 is not known. OBJECTIVE: To summarize our experience in combining flecainide and beta-blockers in high-risk patients with CPVT2. METHODS: All patients with CPVT2 (10 patients) who have high-risk features (syncope, EIVA, or appropriate implantable cardioverter-defibrillator [ICD] shocks) despite beta-blockers with or without calcium channel blockers were treated with a combination of flecainide and beta-blockers. Exercise test was done before and after beginning treatment with flecainide. RESULTS: All patients had EIVA and 4 had appropriate ICD shocks before flecainide treatment. EIVA-included frequent ventricular premature beats and or ventricular tachycardia during the exercise test while on high dose of beta-blockers with or without calcium channel blockers before treatment with flecainide. After combination therapy with flecainide and beta-blockers, EIVA were suppressed completely in all patients. During follow-up of 15.5 ± 10.4 months (range 2-29 months), 8 patients were free of symptoms and free of arrhythmias. Two patients had 1 VT storm episode with recurrent ICD shocks despite repeated normal stress test. CONCLUSIONS: Flecainide can completely prevent ventricular arrhythmia during exercise and partially prevent recurrent ICD shocks in high-risk patients with CPVT2.

Changes in fetal left and right ventricular strain mechanics during normal pregnancy.

BACKGROUND: The aim of this study was to detect normal changes in fetal two-dimensional speckle-tracking echocardiography-derived values for global and regional longitudinal left and right ventricular strain, strain rate, and time to peak (T2P) global strain during pregnancy. METHODS: Forty-four healthy fetuses were examined prospectively during the second-trimester and third-trimester ultrasound examinations (20-24 and 30-34 weeks, respectively). Clips with high frame rates (mean, 120 frames/sec) of two-dimensional (B-mode) grayscale images of apical or basal four-chamber views of both ventricles were used for offline analyses of global and regional walls and segments (basal, mid, and apical) of myocardial strain and strain rate as well as T2P global strain in the longitudinal direction. RESULTS: There were statistically significant decreases in global and regional strain of the right ventricle between the second and third trimesters. No statistically significant changes were observed in global and regional strain of the left ventricle. Global and regional strain rates of both ventricles decreased in a similar way during pregnancy. The mean T2P longitudinal left ventricular global strain (adjusted for heart rate) increased mildly during fetal life. Whereas T2P longitudinal strain of the left ventricle at 20 to 24 weeks was statistically significantly shorter than that of the right ventricle, no difference in T2P longitudinal strain was found at 30 to 34 weeks of gestation between both ventricles. CONCLUSIONS: The establishment of these changes between the second-trimester and third-trimester two-dimensional speckle-tracking echocardiography-derived reference values is a mandatory prerequisite for its use in evaluating (pathologic) changes in both ventricular functions during pregnancy.