Generation of patient-specific induced pluripotent stem cell lines from one patient with Jervell and Lange-Nielsen syndrome, one with type 1 long QT syndrome and two healthy relatives.

Four human iPSC cell lines (one Jervell and Lange-Nielsen Syndrome, one Long QT Syndrome-type 1 and two healthy controls) were generated from peripheral blood obtained from donors belonging to the same family. CytoTune™-iPS 2.0 Sendai Reprogramming Kit (containing OCT3/4, KLF4, SOX2 and cMYC as reprogramming factors) was used to generate all cell lines. The four iPSCs have normal karyotype, express pluripotency markers as determined by RT-PCR and flow cytometry and differentiated spontaneously in vitro into cells of the three germ layers, confirming their pluripotent capacity.

Concealed accessory pathway with long conduction times and incremental properties: a case report.

Concealed AP with Slow and Incremental Conduction. We report a peculiar form of permanent junctional reciprocating tachycardia that occurs only during daytime and physical activity. ECG obtained during tachycardia showed an unusual progressive shortening of the ventriculoatrial (VA) interval that was maximal at the first complex and shortest at the last one before block occurred, always at the accessory pathway level. This phenomenon has not been previously described and appears to be a reverse type of Wenckebach block. It was observed during salvos of spontaneous tachycardia and could be reproduced by right ventricular pacing. The accessory pathway was ablated successfully at the right posteroseptal region, close to the coronary sinus ostium. After ablation, there was no VA conduction, and tachycardia did not recur during a 9-month follow-up period.

Induction of ventricular fibrillation predicts sudden death in patients treated with amiodarone because of ventricular tachyarrhythmias after a myocardial infarction.

OBJECTIVE: To examine the value of programmed electrical stimulation of the heart in predicting sudden death in patients receiving amiodarone to treat ventricular tachyarrhythmias after myocardial infarction. DESIGN: Consecutive patients; retrospective study. SETTING: Referral centre for cardiology, academic hospital. PATIENTS: 106 patients with ventricular tachycardia (n = 77) or ventricular fibrillation (n = 29) late after myocardial infarction. INTERVENTIONS: Programmed electrical stimulation was performed while on amiodarone treatment for at least one month. MEASUREMENTS AND MAIN RESULTS: In 80/106 patients either ventricular fibrillation (n = 15) or sustained monomorphic ventricular tachycardia (n = 65) was induced. After a mean follow up of 50 (SD 40) months (1-144), 11 patients died suddenly and two used their implantable cardioverter debfibrillator. By multivariate analysis two predictors for sudden death were found: (1) inducibility of ventricular fibrillation under amiodarone treatment (P << 0.001), and (2) a left ventricular ejection fraction of < 40% (P < 0.05). The survival rate at one, two, three, and five years was 70%, 62%, 62%, and 40% respectively for patients in whom ventricular fibrillation was induced, and 98%, 96%, 94%, 94% for patients with induced sustained monomorphic ventricular tachycardia. Where there was no sustained arrhythmia, five year survival was 100%. CONCLUSIONS: In patients receiving amiodarone because of life threatening ventricular arrhythmias after myocardial infarction, inducibility of ventricular fibrillation, but not of sustained monomorphic ventricular tachycardia, indicates a high risk of sudden death.

[Ventricular fibrillation in a patient with the permanent form of junctional reciprocating tachycardia]. / Fibrilação ventricular em paciente com forma permanente da taquicardia juncional reciprocante.

A case of a 20 year old young man having the permanent form of junctional reciprocating tachycardia complicated by ventricular fibrillation (VF) is reported. A number of antiarrhythmic drugs either as single or combined therapy fail to control tachycardia. Paroxisms of a faster palpitation which never lasted longer than a few minutes were felt over the last six months before the occurrence of VF. At admission, a narrow QRS tachycardia 250 beats/min was recorded and soon degenerated into VF. After electrical shock with 350J permanent form of junctional tachycardia resumed. Electrophysiologic evaluation identified an accessory pathway with long conducting times in postero-septal location, enhanced atrioventricular node conduction and inducible atrial flutter. The patient underwent successful radiofrequency ablation and is doing well after 18 months of follow-up, being off antiarrhythmic drug and tachycardia free.

Fibrilação; ventricular em pacientes com forma permanente da taquicardia juncional reciprocante / Ventricular fibrillation in a patient with the permanent form of junctional reciprocating tachycardia

Homem de 20 anos, portador de taquicardia de apresentaçäo incessante há longos anos, sem resposta a medicaçöes antiarrítmicas. Seis meses antecedendo a admissäo referia paroxismos de taquicardia mais rápida, de duraçäo curta, autolimitada. Na admissäo apresentava flutter atrial com conduçäo 1:1 (250 bpm) que degenerou em fibrilaçäo ventricular, revertida com 350J. O estudo eletrofisiológico identificou taquicardia atrioventricular, utilizando conexäo anômala "oculta" de localizaçäo póstero-septal deita com conduçäo lenta e propriedade decremental, conduçäo atrioventricular acelerada, observando-se precipitaçäo de fibrilaçäo atrial com resposta rápida pós-atropinizaçäo. Foi submetido a ablaçäo por cateter pro radiofrequência com sucesso. Esta assintomático, 18 meses após o procedimento.

[Atriofascicular connection with slow conduction and longitudinal dissociation. Electrophysiologic evidence and clinical implications]. / Conexão átrio-fascicular com condução lenta e dissociação longitudinal. Comprovação eletrofisiológica e implicações clínicas.

We report on a patient with paroxysmal left bundle branch block-like tachycardia with electrophysiologic findings suggestive of nodoventricular pathway (ventricular pre-excitation dependent on slowing of AV conduction, and accessory pathway with exclusive anterograde conduction). There was no pre-excitation during sinus rhythm but it was brought on by intravenous verapamil. Atrioventricular node conduction curves showed no signs of duality. Diagnosis of an atriofascicular pathway with decremental properties was based on the following findings: 1) absence of AV dissociation during reciprocating tachycardia; 2) absence of fusion beats or narrowing QRS complexes during tachycardia; 3) advancement of right ventricular activation with late atrial extrastimuli delivered during antidromic tachycardia at a time of low right atrium refractoriness; 4) observation that earliest ventricular endocardial electrogram during tachycardia (activation mapping) was simultaneous with the right bundle potential; 5) surgical ablation of the accessory pathway by endocardial incision at the right anterior aspect of the tricuspid ring, far away from the AV node region. Evidences showing anterograde longitudinal dissociation of the accessory pathway included cycle length alternation during tachycardia and duality of accessory pathway conduction times and refractory periods. We hypothesize that reentry occurring in such AV node-like structure could give to a pre-excited tachycardia with AV dissociation mimicking antidromic tachycardia associated with nodoventricular pathway.

[Surgery for Wolff-Parkinson-White syndrome in the first year of life]. / Cirurgia para síndrome de Wolff-Parkinson-White no 1. ano de vida.

A case of surgical treatment for reentrant atrioventricular tachycardia in a 7 months old child is reported. Episodes of tachycardia were repetitive and long-lasting, often leading to signs of hemodynamic impairement, and were not controlled by antiarrhythmic drugs. The electrophysiologic study showed a circus-movement tachycardia utilizing a concealed accessory pathway located at the anterior septal aspect of tricuspid anulus. The child underwent successful surgical treatment by the endocardial technique. Few minutes after weaning from extracorporeal circulation, developed T wave inversion followed by acute right ventricular dysfunction and ventricular fibrillation. Others ischemic like episodes, maybe as a result of coronary artery spasm, occurring in the next 6 hours were successfully treated with isosorbide dinitrate. At 18 months follow-up, the child is free of tachycardia and has normal atrioventricular conduction.

[Transcoronary chemical ablation of ventricular tachycardia in a patient with chronic chagas cardiomyopathy]. / Ablação química transcoronária de taquicardia ventricular em portador de cardiopatia chagásica crônica.

A case of recurrent ventricular tachycardia in the setting of chronic chagasic heart disease refractory to conventional antiarrhythmic agents as well as high doses of amiodarone (600 mg/day) is reported. Left ventriculography disclosed an apical aneurysm and a filling defect image suggestive of a thrombus. Sustained monomorphic ventricular tachycardia with the same QRS configuration as "clinical" tachycardia could be induced by means of right ventricular programmed electrical stimulation. The risk of systemic embolization precluded endocardial activation mapping of ventricular tachycardia. Intracoronary cold saline injections were done during induced ventricular tachycardia looking for a coronary artery branch related to the arrhythmogenic substrate. Cold saline mapping results pointed to an apical site of origin. Next step was intracoronary injection of ethyl alcohol in the distal part of the left anterior descending artery leading to a small and uncomplicated myocardial infarction. Control programmed stimulation was unable to reinduce ventricular tachycardia. Clinical outcome was uneventful and there was no recurrence of clinical arrhythmia in 6 months of follow-up.

[Cardiomyopathy induced by incessant ventricular tachycardia ("tachycardiomyopathy"): cure after control of arrhythmia]. / Miocardiopatia induzida por taquicardia ventricular incessante ("taquicardiomiopatia"). Cura após controle da arritmia.

A case of severe dilated cardiomyopathy in a young boy presenting with incessant ventricular tachycardia, who had been referred for heart transplantation is reported. Complete resolution of dilated cardiomyopathy followed arrhythmia control with oral amiodarone. Such evolution strongly suggests a cause-effect relationship between incessant ventricular tachycardia and dilated cardiomyopathy in this particular case.

[Ventricular fibrillation in a patient with ventricular dysplasia and mitral valve prolapse]. / Fibrilação ventricular em portador de displasia ventricular e prolapso valvar mitral.

A 30 year-old male patient with arrhythmogenic right ventricular dysplasia was submitted to implantation an automatic cardioverter-defibrillator. So far he is well in a follow-up of 7 months.

Exercise-induced sustained symptomatic ventricular tachycardia: incidence, clinical, angiographic and electrophysiologic characteristics.

Among 112 patients with sustained ventricular tachycardia, 15 were found to have exercise-induced symptomatic ventricular tachycardia. This population was divided into two subgroups: group 1A included five patients with coronary artery disease and group 1B consisted of 10 patients with no structural heart disease. All patients underwent clinical examination, exercise electrocardiography, left ventriculography, coronary angiography (n = 14) and electrophysiologic study. In group 1B, right ventriculography (n = 7), M mode and two-dimensional echocardiography were also obtained. Group 1A patients were compared with a population of 27 patients with coronary artery disease and chronic sustained ventricular tachycardia not related to exercise (group 2). There were no statistically significant differences between group 1A and group 2 in terms of age, sex, incidence of prior myocardial infarction, NYHA functional class, angina pectoris, symptoms during arrhythmia, severity and extent of coronary arterial lesions, ventricular dysfunction and wall motion abnormalities. In group 1B, coronary angiography and right and left ventricular function were normal. During electrophysiologic study, ventricular tachycardia was initiated in four group 1A patients. In group 1B, ventricular tachycardia was initiated in eight patients. In four of these patients ventricular pacing had to be combined with isoproterenol administration. In group 2, ventricular tachycardia was induced in 26/27 patients. From this study we conclude that in patients with coronary artery disease the electrophysiologic substrate of exercise-related sustained ventricular tachycardia does not differ from the substrate of non-exercise-related ventricular tachycardia. Re-entry is the most likely electrophysiologic mechanism. In patients without structural heart disease, the mechanism of the arrhythmia remains speculative.