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Conventional treatment strategies for catecholaminergic polymorphic ventricular tachycardia (CPVT) include avoidance of strenuous exercise and competitive sports, drugs such as ß‐blockers and flecainide and, cervical sympathectomy. An implantable cardioverter‐defibrillator (ICD) has been utilized if the response to these strategies is inadequate; however, ICD use in CPVT patients, in addition to usual complications, is associated with an increased risk of life‐threatening electrical storm. Ivabradine is a selective inhibitor of hyperpolarization‐activated cyclic nucleotide‐gated potassium channel 4 generated funny current (If), which has been shown to be efficacious in suppression of inappropriate sinus tachycardia, junctional tachycardia, atrial tachycardia, and ventricular ectopy in humans. We report an 18‐year‐old male with a severe CPVT phenotype refractory to flecainide, nadolol, and sympathectomy who exhibited suppression of ventricular arrhythmias after initiation of ivabradine. These findings are of importance as ivabradine could be an important add‐on therapy in CPVT patients who are drug refractory or are unable to continue conventional therapies at the recommended doses. [ABSTRACT FROM AUTHOR]

We report a 17‐year‐old boy with a large RYR2 exon 3 deletion who has a severe catecholaminergic polymorphic ventricular tachycardia (CPVT) phenotype characterized by refractoriness to both nadolol and flecainide which has previously not been reported in this subgroup of CPVT patients. Treatment options in a patient like ours are therefore limited and sympathectomy and implantable cardioverter‐defibrillator implantation should be considered early in the treatment course as was done in this patient. In contrast to other CPVT patients who do not usually have structural cardiac abnormalities, these patients are at a high risk of developing left ventricular noncompaction or dilated cardiomyopathy and therefore might benefit from cardiac imaging at regular intervals. [ABSTRACT FROM AUTHOR]

Exercise-induced syncope should alert clinicians to the possibility of LQTS and must be distinguished from other malignant causes of syncope such as hypertrophic cardiomyopathy, catecholaminergic ventricular tachycardia, and arrhythmogenic right ventricular cardiomyopathy. Emerging genotype-phenotype links have connected mutations resulting in LQTS with risk of developing atrial fibrillation and cardiomyopathy. [ABSTRACT FROM AUTHOR]

Abstract: An impairment of cardiovascular reflexes may be the result of functional alterations in the G proteins intracellular signaling produced by functional genes'' polymorphisms. The aim was to evaluate the relationships between single nucleotide polymorphisms in genes encoding G-proteins signaling pathways and syncopal patients with severe clinical manifestation. Methods and results: From 307 syncopal patients free from any other diseases 83 (27%) had at least one malignant episode of syncope with a significant injury as fractures. There was 1.9 malignant spells per patient. All patients were tilted and genotyped by polymerase chain reaction followed by restriction fragment length polymorphism method. 74 healthy volunteers with negative history of syncope constituted the control group were also genotyped. Following polymorphisms were detected: C393T in gene encoding the alfa-subunit of Gs-protein (GNAS1), C825T of gene for G-protein beta 3 subunit (GNB3) and C1114G for the gene of cardiac regulator of G-protein signaling (RGS2). We found an association with lower risk of malignant syncope in positive tilting patients during passive phase of the test compared to NTG-enhanced (OR 0.38; 95% CI 0.15–0.95; P =0.04). No difference between healthy controls and patients in the alleles frequency was found (P >0.05). Neither the 393T allele of GNAS1 and 825T allele of GNB3 nor 1114G allele of RGS2 was associated with enhanced risk of severe clinical manifestation (P >0.05). Conclusions: The studied single nucleotide polymorphisms of genes encoding G-proteins signaling pathways seem to be not connected with the severe clinical manifestation of syncope. [Copyright &y& Elsevier]

The management of unexplained syncope begins with the patient's history and physical examination, which are oriented to help separate benign from serious causes. Malignant etiologies are more likely to occur with exertional syncope. Cardiac causes should be considered, particularly cardiomyopathy, postoperative congenital heart disease, right ventricular dysplasia, anomalous coronary artery, pulmonary artery hypertension, myocarditis, long QT syndrome, and Wolff-Parkinson-White syndrome. Neurological and metabolic disorders may underlie a syncope episode. After malignant causes of syncope have been excluded and the diagnosis of neurocardiac syncope has been established, treatment strategies include behavior modification, salt and increased fluids, and pharmacological agents. Efficacious agents include β-blockers, dysopyramide, fludrocortisones, and alpha agents. Yet, behavior modification alone may be as effective as salt or pharmacological therapy. Because the natural history of neurocardiac syncope in children is spontaneous resolution, it is appropriate to try the simple measures before introducing drug therapy. [ABSTRACT FROM AUTHOR]