RESUMEN
[Figure: see text].
Asunto(s)
Ablación por Catéter , Frecuencia Cardíaca , Fibrilación Ventricular/cirugía , Complejos Prematuros Ventriculares/cirugía , Potenciales de Acción , Adulto , Anciano , Antiarrítmicos/uso terapéutico , California , Estudios de Casos y Controles , Ablación por Catéter/efectos adversos , Ablación por Catéter/mortalidad , Desfibriladores Implantables , Cardioversión Eléctrica/instrumentación , Técnicas Electrofisiológicas Cardíacas , Femenino , Frecuencia Cardíaca/efectos de los fármacos , Humanos , Masculino , Persona de Mediana Edad , Estudios Prospectivos , Factores de Tiempo , Resultado del Tratamiento , Fibrilación Ventricular/diagnóstico , Fibrilación Ventricular/mortalidad , Fibrilación Ventricular/fisiopatología , Complejos Prematuros Ventriculares/diagnóstico , Complejos Prematuros Ventriculares/mortalidad , Complejos Prematuros Ventriculares/fisiopatologíaAsunto(s)
Técnicas de Ablación , Arritmias Cardíacas , Estimulación Cardíaca Artificial , Cardioversión Eléctrica , Técnicas Electrofisiológicas Cardíacas , Insuficiencia Cardíaca , Potenciales de Acción , Animales , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/epidemiología , Arritmias Cardíacas/fisiopatología , Arritmias Cardíacas/terapia , Desfibriladores Implantables , Cardioversión Eléctrica/instrumentación , Insuficiencia Cardíaca/diagnóstico , Insuficiencia Cardíaca/epidemiología , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/terapia , Frecuencia Cardíaca , Humanos , Valor Predictivo de las Pruebas , Resultado del TratamientoAsunto(s)
Arritmias Cardíacas , Electrofisiología Cardíaca/tendencias , Técnicas Electrofisiológicas Cardíacas/tendencias , Técnicas de Ablación/tendencias , Potenciales de Acción , Animales , Antiarrítmicos/uso terapéutico , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/genética , Arritmias Cardíacas/fisiopatología , Arritmias Cardíacas/terapia , Estimulación Cardíaca Artificial/tendencias , Difusión de Innovaciones , Cardioversión Eléctrica/tendencias , Predisposición Genética a la Enfermedad , Frecuencia Cardíaca , Humanos , Fenotipo , Factores de Riesgo , Resultado del TratamientoRESUMEN
BACKGROUND: Previous observations have reported that the number of pacing stimuli required to entrain a tachycardia varies on the basis of arrhythmia type and location, but a quantitative formulation of the number needed to entrain (NNE) that unifies these observations has not been characterized. OBJECTIVE: We sought to investigate the relationship between the number of pacing stimulations, the tachycardia cycle length (TCL), the overdrive pacing cycle length (PCL), and the postpacing interval (PPI) to accurately estimate the timing of tachycardia entrainment. METHODS: First, we detailed a mathematical derivation unifying electrophysiological parameters with empirical confirmation in 2 patients undergoing catheter ablation of typical atrial flutter. Second, we validated our formula in 44 patients who underwent various catheter ablation procedures. For accuracy, we corrected for rate-related changes in conduction velocity. RESULTS: We derived the equations NNE = |(PPI - TCL)/(TCL - PCL)| + 1 and Tachycardia advancement = (NNE - 1) × (TCL - PCL) - (PPI - TCL), which state that the NNE and the amount of tachycardia advancement on the first resetting stimulation are determined using regularly measured intracardiac parameters. In the retrospective cohort, the observed PPI - TCL highly correlated with the predicted PPI - TCL (mean difference 5.8 ms; r = 0.97; P < .001), calculated as PPI - TCL = (NNE - 1) × (TCL - PCL) - tachycardia advancement. CONCLUSION: The number of pacing stimulations required to entrain a reentrant tachycardia is predictable at any PCL after correcting for cycle length-dependent changes in conduction velocity. This relationship unifies established empirically derived diagnostic and mapping criteria for supraventricular tachycardia and ventricular tachycardia. This relationship may help elucidate when antitachycardia pacing episodes are ineffective or proarrhythmic and could potentially serve as a theoretical basis to customize antitachycardia pacing settings for improved safety and effectiveness.
Asunto(s)
Estimulación Cardíaca Artificial/métodos , Técnicas Electrofisiológicas Cardíacas/métodos , Sistema de Conducción Cardíaco/fisiopatología , Frecuencia Cardíaca/fisiología , Modelos Teóricos , Taquicardia Ventricular/diagnóstico , Adulto , Femenino , Estudios de Seguimiento , Humanos , Masculino , Persona de Mediana Edad , Pronóstico , Estudios Retrospectivos , Taquicardia Ventricular/fisiopatología , Taquicardia Ventricular/terapiaRESUMEN
BACKGROUND: Because the His bundle is intrinsic to the circuit in orthodromic reciprocating tachycardia and remote from that of atrioventricular nodal reentrant tachycardia (AVNRT), pacing the His bundle during supraventricular tachycardia (SVT) may be useful to distinguish these arrhythmias. OBJECTIVE: The purpose of this study was to test the hypothesis that His overdrive pacing (HOP) would affect SVT immediately for orthodromic reciprocating tachycardia and in a delayed manner for AVNRT. METHODS: Once SVT was induced, HOP was performed by pacing the His bundle 10-30 ms faster than the SVT cycle length. The maneuver was determined to have entered the tachycardia circuit when a nonfused His-capture beat advanced or delayed the subsequent atrial electrogram by ≥10 ms or when the tachycardia was terminated. The number of beats required to enter each tachycardia with HOP was recorded. RESULTS: HOP was performed during 66 SVTs (26 atrioventricular reciprocating tachycardia [AVRT] and 40 AVNRT). Entry into the tachycardia within 1 beat had sensitivity of 92%, specificity of 92%, positive predictive value (PPV) of 89% and negative predictive value (NPV) of 95% to confirm the diagnosis of AVRT. A cutoff ≥3 beats to enter the circuit had sensitivity of 90%, specificity of 92%, PPV of 95% and NPV of 86% to confirm the diagnosis of AVNRT. HOP had sensitivity, specificity, PPV, and NPV of 100% for distinguishing septal AVRT from atypical AVNRT. CONCLUSION: HOP during SVT is a novel technique for distinguishing orthodromic reciprocating tachycardia from AVNRT. It can reliably distinguish between these arrhythmias with high sensitivity and specificity.
Asunto(s)
Fascículo Atrioventricular/fisiopatología , Estimulación Cardíaca Artificial/métodos , Sistema de Conducción Cardíaco/fisiopatología , Taquicardia por Reentrada en el Nodo Atrioventricular/diagnóstico , Taquicardia Reciprocante/diagnóstico , Adolescente , Adulto , Diagnóstico Diferencial , Electrocardiografía , Técnicas Electrofisiológicas Cardíacas , Femenino , Estudios de Seguimiento , Humanos , Masculino , Estudios Retrospectivos , Taquicardia por Reentrada en el Nodo Atrioventricular/fisiopatología , Taquicardia por Reentrada en el Nodo Atrioventricular/terapia , Taquicardia Reciprocante/fisiopatología , Taquicardia Reciprocante/terapia , Adulto JovenRESUMEN
INTRODUCTION: Fascicular tachycardia (FT) is an uncommon cause of monomorphic sustained ventricular tachycardia (VT). We describe 6 cases of FT with multiform QRS morphologies. METHODS AND RESULTS: Six of 823 consecutive VT cases were retrospectively analyzed and found attributable to FT with multiform QRS patterns, with 3 cases exhibiting narrow QRS VT as well. All underwent electrophysiology study including fascicular potential mapping, entrainment pacing, and electroanatomic mapping. The first 3 cases describe similar multiform VT patterns with successful ablation in the upper mid septum. Initially, a right bundle branch block (RBBB) VT with superior axis was induced. Radiofrequency catheter ablation (RFCA) targeting the left posterior fascicle (LPF) resulted in a second VT with RBBB inferior axis. RFCA in the upper septum just apical to the LBB potential abolished VT in all cases. Cases 4 and 5 showed RBBB VT with alternating fascicular block compatible with upper septal dependent VT, resulting in bundle branch reentrant VT (BBRT) after ablation of LPF and left anterior fascicle (LAF). Finally, Cases 5 and 6 demonstrated spontaneous shift in QRS morphology during VT, implicating participation of a third fascicle. In Case 6, successful ablation was achieved over the proximal LAF, likely representing insertion of the auxiliary fascicle near the proximal LAF. CONCLUSIONS: Multiform FTs show a reentrant mechanism using multiple fascicular branches. We hypothesize that retrograde conduction over the septal fascicle produces alternate fascicular patterns as well as narrow VT forms. Ablation of the respective fascicle was successful in abolishing FT but does not preclude development of BBRT unless septal fascicle is targeted and ablated.