Aims Calmodulinopathies are rare life-threatening arrhythmia syndromes which affect mostly young individuals and are, caused by mutations in any of the three genes (CALM 1–3) that encode identical calmodulin proteins. We established the International Calmodulinopathy Registry (ICalmR) to understand the natural history, clinical features, and response to therapy of patients with a CALM-mediated arrhythmia syndrome. Methods and results A dedicated Case Report File was created to collect demographic, clinical, and genetic information. ICalmR has enrolled 74 subjects, with a variant in the CALM1 (n = 36), CALM2 (n = 23), or CALM3 (n = 15) genes. Sixty-four (86.5%) were symptomatic and the 10-year cumulative mortality was 27%. The two prevalent phenotypes are long QT syndrome (LQTS; CALM-LQTS, n = 36, 49%) and catecholaminergic polymorphic ventricular tachycardia (CPVT; CALM-CPVT, n = 21, 28%). CALM-LQTS patients have extremely prolonged QTc intervals (594 ± 73 ms), high prevalence (78%) of life-threatening arrhythmias with median age at onset of 1.5 years [interquartile range (IQR) 0.1–5.5 years] and poor response to therapies. Most electrocardiograms (ECGs) show late onset peaked T waves. All CALM-CPVT patients were symptomatic with median age of onset of 6.0 years (IQR 3.0–8.5 years). Basal ECG frequently shows prominent U waves. Other CALM-related phenotypes are idiopathic ventricular fibrillation (IVF, n = 7), sudden unexplained death (SUD, n = 4), overlapping features of CPVT/LQTS (n = 3), and predominant neurological phenotype (n = 1). Cardiac structural abnormalities and neurological features were present in 18 and 13 patients, respectively. Conclusion Calmodulinopathies are largely characterized by adrenergically-induced life-threatening arrhythmias. Available therapies are disquietingly insufficient, especially in CALM-LQTS. Combination therapy with drugs, sympathectomy, and devices should be considered.

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a relatively common surgical approach for closed procedures in infants and children with congenital cardiac malformations. This approach results in division of the latissimus dorsi and serratus anterior muscles. Division of these muscles can result in significant postoperative pain, diminished pulmonary function, and marked impairment of motion.The thoracotomy incision may also result in longterm physical impairment and deformity. Scoliosis has been reported to develop with an incidence of 22% several years after left posterolateral thoracotomy for correction of aortic coarctation in infancy and childhood. 1 The long-term musculoskeletal consequences of thoracotomy for surgical treatment of congenital cardiac disease, however, have seldom been evaluated. [2][3][4][5][6] With this in mind, we sought to determine whether a posterolateral thoracotomy performed in children with congenital cardiac disease influences the postoperative anatomy and function of the musculoskeletal system. Materials and methodsWe evaluated 49 children, 28 boys and 21 girls, undergoing surgery through a posterolateral thoracotomy in the forth-intercostal space for treatment of congenital cardiac disease at Hacettepe University Hospital. An additional median sternotomy was needed in 9 (18%) of the patients.By means of a general clinical examination and radiological studies, we evaluated thoracic symmetry, Cardiol Young 2003; 13: 264-267 Abstract The standard surgical approach for closed heart procedures in small infants and children is to use a posterolateral thoracotomy incision, which results in the division of the latissimus dorsi and serratus anterior muscles. The aim of our study was to determine the frequency and type of musculoskeletal deformities in children undergoing surgery with this approach for congenital cardiac disease.We included 49 children, 28 boys and 21 girls, in the study. Their mean age was 10.2 Ϯ 4.8 years, the mean age at the time of surgery was 3.8 Ϯ 4.0 years, and they were evaluated at an average of 6 years after the thoracotomy. Of the patients, 94% had various musculoskeletal deformities. Scoliosis was observed in 15 patients (31%) but only in two patients did the curves exceed 25 degrees. Of these patients, three-fifths had aortic coarctation. Elevation of the shoulder was seen in 61%, winged scapula in 77%; while 14% had asymmetry of the thoracic wall due to the atrophy of the serratus anterior muscle. Deformity of the thoracic cage was observed in 18%; and 63% had asymmetry of the nipples.Thus, we found that musculoskeletal deformities are frequent after thoracotomies in children with congenital cardiac disease. Patients who have undergone such procedures for cardiac or noncardiac surgery should be followed until their skeletal maturation is complete. Techniques sparing the serratus anterior and latissimus dorsi muscles should be preferred. These adverse effects of thoracotomy may be another reason for using interventional procedures in these cases.

Catecholaminergic polymorphic ventricular tachycardia is a rare entity that can occur in children without cardiac disease and with a normal QT interval. It may cause syncope, convulsions, and sudden death during physical activity or emotional distress. We report the clinical features, treatment, and follow-up of 16 children with this diagnosis, emphasizing the potentially fatal nature of the disease.The mean age of patients at the onset of symptoms and at the time of diagnosis was 7.8 plus or minus 2.5 years, and 10.6 plus or minus 3.5 years, respectively. Syncope was the main complaint in 11, and 7 were treated as erroneously as having epilepsy. Diagnosis was confirmed by exercise and/or infusion of isoproterenol. Once the diagnosis was made, we started propranolol in all patients, and added verapamil if ventricular tachycardia was still inducible on a treadmill exercise test. An intracardiac defibrillator was implanted in 4 patients. Of the 16 patients, 4 died suddenly, giving a rate of mortality of 25%. In 2 of those dying suddenly, there was evidence of poor compliance to the recommended treatment. Another 2 patients had been resuscitated because of sudden cardiac arrest.Catecholaminergic polymorphic ventricular tachycardia must be considered in the differential diagnosis of syncope in children without heart disease but with a normal QT interval. Medical treatment with propranolol and verapamil may decrease the incidence of arrhythmia. Implantation of intracardiac defibrillators should be considered in those resistant to drug therapy. Delay in diagnosis, and inadequate treatment, can result in sudden cardiac death.

Heart rate variability (HRV) is a noninvasive index of the neural activity of the heart. Although also influenced by the sympathetic activity of the heart, HRV is essentially determined by the vagal stimulation of the heart. Several HRV abnormalities have been described in adults with diabetes mellitus. However, there are few data on HRV in children with diabetes mellitus. In the present study, HRV was assessed in seven healthy children, 10 diabetic children with good glycemic control and 11 diabetic children with poor glycemic control. All had normal standard cardiac autonomic function tests, obtained from 24-h Holter tapes. HRV was measured by calculating six time-domain (mean R-R interval (RR), standard deviation of the R-R interval [SDRR], standard deviation of the mean of 288 R-R intervals [SDANN], the mean of the 288 standard deviations computed for each 5-min period [SD], percentage of differences of adjacent R-R intervals of > 50 msec for the entire 24 h [pNN50], and the root mean square of successive differences [rMSSD]) and four frequency-domain (low frequency [LF], high frequency [HF], total heart rate power spectra, and LF/HF ratio) indexes. SD, pNN50, rMSSD, LF, HF and total heart rate power spectra were markedly and significantly reduced in diabetic children with poor metabolic control. The 24-h variation of low- and high-frequency components of heart rate power spectra of the latter children had a different shape. Thus, diabetic children with poor metabolic control (elevated HbA1c and B2M levels) have a low HRV compared to those diabetic children with good control and healthy children.(ABSTRACT TRUNCATED AT 250 WORDS)

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Since many of rhythm abnormalities, including life-threatening ventricular arrhythmias, may be seen in patients with IVNC, children with IVNC should be screened for arrhythmias. An ICD may be the best treatment for some of these patients.

Isolated noncompaction of the ventricular myocardium is a rare congenital cardiomyopathy resulting from an arrest in normal endomyocardial embryogenesis. The diagnosis can be made echocardiographically, and the entity may be associated with problems of cardiac rhythm. We describe two illustrative cases, with Wolf-Parkinson-White syndrome in one, and left bundle branch block in the other. We emphasize that children with problems of rhythm and findings suggestive for left ventricular cardiomyopathy, either hypertrophic or dilated; should be investigated to exclude isolated noncompaction of the ventricular myocardium.