RESUMO
In a series of 14 patients undergoing transseptal catheterization for ablation of left-sided accessory pathways, hydrogen appearance time was used to detect left-to-right shunting after removal of the catheter. Six of the 12 patients who had no evidence of shunt before catheterization had evidence of shunting after the procedure.
Assuntos
Cateterismo Cardíaco/efeitos adversos , Ablação por Cateter/métodos , Comunicação Interatrial/complicações , Complicações Pós-Operatórias , Taquicardia por Reentrada no Nó Atrioventricular/cirurgia , Administração por Inalação , Adolescente , Adulto , Ablação por Cateter/efeitos adversos , Ecocardiografia , Eletrocardiografia , Feminino , Sistema de Condução Cardíaco/cirurgia , Comunicação Interatrial/cirurgia , Humanos , Hidrogênio/administração & dosagem , Masculino , Pessoa de Meia-Idade , Complicações Pós-Operatórias/diagnóstico , Taquicardia por Reentrada no Nó Atrioventricular/etiologiaRESUMO
INTRODUCTION: Ventricular tachycardia is commonly seen in patients following surgical repair for tetralogy of Fallot. The technique of ablation for this arrhythmia is not well defined. METHODS AND RESULTS: In two patients with ventricular tachycardia following surgical repair of tetralogy of Fallot, the traditional indicators for a site for ventricular tachycardia ablation did not yield cure. Based on careful mapping, the circuit was found to involve the isthmus between the outflow tract patch and the tricuspid annulus; linear radiofrequency lesions across this isthmus resulted in cure of ventricular tachycardia. Not only was the tachycardia no longer inducible, but bidirectional block at the line of ablation confirmed interruption of the reentrant circuit. CONCLUSION: A linear radiofrequency lesion was effective in eliminating ventricular tachycardia in both patients. The demonstration of bidirectional block confirms a cure independent of inducibility of ventricular tachycardia.
Assuntos
Ablação por Cateter , Taquicardia Ventricular/cirurgia , Tetralogia de Fallot/cirurgia , Adulto , Eletrocardiografia , Humanos , Masculino , Taquicardia Ventricular/complicações , Taquicardia Ventricular/fisiopatologia , Tetralogia de Fallot/complicações , Tetralogia de Fallot/fisiopatologiaRESUMO
The clinical variables affecting DFT for ICD systems are not completely determined, especially with regard to biphasic shocking devices. To distinguish which factors correlate with DFT, we examined data from patients who were enrolled in the Ventak P2/Endotak protocol. A total of 284 patients were enrolled in the study. Two patients had a DFT > 25 J and did not receive the device; 154 did not undergo stepdown to failure DFT testing. The remaining 128 patients had formal DFT testing and were suitable for analysis. Variables available for analysis included age, body surface area (BSA), LVEF, gender, lead configuration, primary arrhythmia, primary cardiac disease, and use of cardioactive medication. Data were evaluated using regression analysis, fitting DFT (range, 1-25 J, mean 11 +/- 5 J) as a function of each variable. As a univariate predictor. BSA was found to be significant in predicting DFT, but accounted for only 9% of the total variation on the DFT (P < 0.01, r = 0.3). This study suggests that DFT using a biphasic shocking waveform is modestly in fluenced by the BSA of the patient. Other specific factors, including LVEF, do not predict DFT.
Assuntos
Desfibriladores Implantáveis , Cardioversão Elétrica/métodos , Fatores Etários , Amiodarona/uso terapêutico , Antiarrítmicos/uso terapêutico , Arritmias Cardíacas/tratamento farmacológico , Arritmias Cardíacas/terapia , Superfície Corporal , Estimulação Elétrica , Eletrodos Implantados , Desenho de Equipamento , Feminino , Previsões , Cardiopatias/complicações , Humanos , Masculino , Pessoa de Meia-Idade , Análise de Regressão , Fatores Sexuais , Volume Sistólico , Propriedades de Superfície , Toracotomia , Função Ventricular EsquerdaRESUMO
In summary, this study reports 2 important findings: (1) AV nodal modification using the conservative protocol we describe reduces long-term success for ventricular rate control during atrial fibrillation but eliminates the incidence of permanent AV block; (2) directed lesions that eliminate clinical AV nodal reentry slow ventricular response to acute atrial fibrillation but are not sufficient to control ventricular response of chronic atrial fibrillation. Further refinement of these techniques may allow an optimal balance between rate control and avoidance of permanent pacing.
Assuntos
Fibrilação Atrial/cirurgia , Nó Atrioventricular/cirurgia , Ablação por Cateter , Taquicardia por Reentrada no Nó Atrioventricular/cirurgia , Função Ventricular/fisiologia , Adulto , Idoso , Fibrilação Atrial/fisiopatologia , Estimulação Cardíaca Artificial , Estudos de Casos e Controles , Eletrocardiografia Ambulatorial , Feminino , Frequência Cardíaca/fisiologia , Humanos , Masculino , Pessoa de Meia-Idade , Taquicardia por Reentrada no Nó Atrioventricular/fisiopatologiaRESUMO
The use of non-thoracotomy endocardial implantable defibrillators with pacing capabilities has increased substantially over the past 2 years. This report demonstrates that the pacing threshold increases in some patients after endocardial defibrillation, and substantiates the practice of using maximal pacing output after endocardial defibrillation.
Assuntos
Cardiomiopatia Dilatada/fisiopatologia , Doença das Coronárias/fisiopatologia , Desfibriladores Implantáveis , Sistema de Condução Cardíaco/fisiopatologia , Adulto , Idoso , Cardiomiopatia Dilatada/terapia , Doença das Coronárias/terapia , Feminino , Humanos , Masculino , Pessoa de Meia-IdadeAssuntos
Pressão Sanguínea/efeitos dos fármacos , Cocaína/farmacologia , Coração/efeitos dos fármacos , Administração Intranasal , Adulto , Pressão Sanguínea/fisiologia , Cocaína/administração & dosagem , Eletrocardiografia , Eletrofisiologia , Feminino , Coração/fisiologia , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Pessoa de Meia-Idade , Cloreto de Sódio/farmacologiaRESUMO
Stored electrograms enhance the ability to evaluate therapy episodes in the third-generation implantable cardioverter defibrillator. These electrograms are recorded from either the shocking or rate sensing leads, but not both. As a result, differentiation of certain types of sensing abnormalities may be difficult prior to surgical exploration. We present a case of rate sensing lead failure due to an insulation break. Several minutes of recording of the event marker in the laboratory failed to document any abnormal sensing; the diagnosis was made by recording the event marker on a 24-hour continuous (Holter) monitor. The Holter monitor/event marker combination was of substantial diagnostic value and allowed for a more focused surgical evaluation and treatment.
Assuntos
Desfibriladores Implantáveis , Eletrocardiografia Ambulatorial , Eletrodos Implantados , Desenho de Equipamento , Falha de Equipamento , Humanos , Masculino , Pessoa de Meia-Idade , Taquicardia Ventricular/terapiaAssuntos
Adenosina , Estimulação Cardíaca Artificial/métodos , Síndromes de Pré-Excitação/diagnóstico , Adenosina/administração & dosagem , Adulto , Eletrocardiografia , Sistema de Condução Cardíaco/anormalidades , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes de Pré-Excitação/fisiopatologiaRESUMO
Intranasal cocaine, 2 to 3 mg/kg body weight, is a commonly used local anesthetic for rhinolaryngologic procedures, and many persons who abuse it ingest a similar amount. Previous studies in humans showed that this dose of cocaine causes coronary vasoconstriction, and studies in animals showed that larger amounts given intravenously diminish myocardial performance. This study assessed the hemodynamic effects of intranasal cocaine, 2 mg/kg, in humans. In 15 patients (8 men and 7 women, aged 30 to 70 years) referred for cardiac catheterization, heart rate, systemic arterial pressure, cardiac index, pulmonary capillary wedge and pulmonary artery pressures and left ventricular pressure and its first derivative (dP/dt) were measured before and 15, 30 and 45 min after intranasal administration of saline solution (n = 5) or cocaine, 2 mg/kg (n = 10). No variable changed with saline solution. In those given cocaine, there was an increase in heart rate (17 +/- 16%, mean +/- SD), mean systemic arterial pressure (8 +/- 7%), cardiac index (18 +/- 18%) and positive and negative dP/dt (18 +/- 20% and 15 +/- 22%, respectively) (p less than 0.05 for all). Thus, intranasal cocaine in a dose similar to that used medicinally or "recreationally" does not exert a deleterious influence on intracardiac pressures and left ventricular performance.