Assuntos
Potenciais de Ação , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Taquicardia Ventricular/fisiopatologia , Ablação por Cateter , Desfibriladores Implantáveis , Cardioversão Elétrica/instrumentação , Eletrocardiografia Ambulatorial , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/cirurgia , Humanos , Masculino , Pessoa de Meia-Idade , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/terapia , Fatores de Tempo , Resultado do TratamentoRESUMO
The recognition of the presence, location, and properties of unusual accessory pathways for atrioventricular conduction is an exciting, but frequently a difficult, challenge for the clinical cardiac arrhythmologist. In this third part of our series of reviews, we discuss the different steps required to come to the correct diagnosis and management decision in patients with nodofascicular, nodoventricular, and fasciculo-ventricular pathways. We also discuss the concealed accessory atrioventricular pathways with the properties of decremental retrograde conduction that are associated with the so-called permanent form of junctional reciprocating tachycardia. Careful analysis of the 12-lead electrocardiogram during sinus rhythm and tachycardias should always precede the investigation in the catheterization room. When using programmed electrical stimulation of the heart from different intracardiac locations, combined with activation mapping, it should be possible to localize both the proximal and distal ends of the accessory connections. This, in turn, should then permit the determination of their electrophysiologic properties, providing the answer to the question "are they incorporated in a tachycardia circuit?". It is this information that is essential for decision-making with regard to the need for catheter ablation, and if necessary, its appropriate site.
Assuntos
Feixe Acessório Atrioventricular/cirurgia , Potenciais de Ação , Ablação por Cateter , Frequência Cardíaca , Pré-Excitação Tipo Mahaim/cirurgia , Taquicardia Reciprocante/cirurgia , Feixe Acessório Atrioventricular/fisiopatologia , Ablação por Cateter/efeitos adversos , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Humanos , Pré-Excitação Tipo Mahaim/diagnóstico , Pré-Excitação Tipo Mahaim/fisiopatologia , Valor Preditivo dos Testes , Taquicardia Reciprocante/diagnóstico , Taquicardia Reciprocante/fisiopatologia , Resultado do TratamentoRESUMO
Recognition of the presence, location, and properties of unusual accessory pathways for atrioventricular conduction is an exciting, frequently difficult, challenge for the clinical cardiac arrhythmologist. In this second part of our series of reviews relative to this topic, we discuss the steps required to achieve the correct diagnosis and appropriate management in patients with the so-called "Mahaim" variants of pre-excitation. We indicate that, nowadays, it is recognized that these abnormal rhythms are manifest because of the presence of atriofascicular pathways. These anatomical substrates, however, need to be distinguished from the other long and short accessory pathways which produce decremental atrioventricular conduction. The atriofascicular pathways, along with the long decrementally conducting pathways, have their atrial components located within the vestibule of the tricuspid valve. The short decremental pathways, in contrast, can originate in the vestibules of either the mitral or tricuspid valves. As a starting point, careful analysis of the 12-lead electrocardiogram, taken during both sinus rhythm and tachycardias, should precede any investigation in the catheterization room. When assessing the patient in the electrophysiological laboratory, the use of programmed electrical stimulation from different intracardiac locations, combined with entrainment technique and activation mapping, should permit the establishment of the properties of the accessory pathways, and localization of its proximal and distal ends. This should provide the answer to the question "is the pathway incorporated into the circuit underlying the clinical tachycardia". That information is essential for decision-making with regard to need, and localization of the proper site, for catheter ablation.
Assuntos
Feixe Acessório Atrioventricular/cirurgia , Potenciais de Ação , Ablação por Cateter , Frequência Cardíaca , Pré-Excitação Tipo Mahaim/cirurgia , Feixe Acessório Atrioventricular/fisiopatologia , Ablação por Cateter/efeitos adversos , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Humanos , Pré-Excitação Tipo Mahaim/diagnóstico , Pré-Excitação Tipo Mahaim/fisiopatologia , Valor Preditivo dos Testes , Resultado do TratamentoRESUMO
BACKGROUND: The differential diagnosis of a supraventricular tachycardia (SVT) is accomplished using a number of pacing maneuvers. The incidence and mechanism of a single ventricular premature beat (VPB) on initiation and termination of tachycardia were evaluated during programmed electrical stimulation (PES) of the heart in patients with the two most common regular SVTs: atrioventricular re-entrant tachycardia (AVNRT) and orthodromic atrioventricular tachycardia (AVRT). METHODS: Three hundred and thirty-seven consecutive patients aged above 18 years with an inducible sustained AVNRT or AVRT were prospectively enrolled. Patients with more than one tachyarrhythmia mechanism were excluded. Two hundred and seventeen patients (64.4%) had typical slow/fast AVNRT and 120 (35.6%) had an orthodromic AVRT using a rapidly conducting accessory pathway for V-A conduction. In this cross-sectional study, we specifically report the analysis of tachycardia induction and termination by a single VPB. RESULTS: Tachycardia induction with a single VPB during sinus rhythm was seen in 7 of 120 AVRT and in only one of the 217 patients with AVNRT, (5.8% vs. 0.3%, p < 0.05). When a single VPB was delivered during basic ventricular pacing these values were 28% versus 4%, respectively, (p < 0.001). Termination of tachycardia by a single VPB was observed in nine (4.1%) patients with AVNRT and in 57 (47.5%) with AVRT (p < 0.001). CONCLUSION: Initiation of SVT by a single VPB during sinus rhythm was uncommon and favored AVRT. Termination of SVT by a single VPB was commonly seen in AVRT but rarely in AVNRT. These findings can be of help when interpreting a noninvasive arrhythmia event recording.
Assuntos
Eletrocardiografia , Taquicardia Supraventricular/etiologia , Taquicardia Supraventricular/fisiopatologia , Complexos Ventriculares Prematuros/complicações , Complexos Ventriculares Prematuros/fisiopatologia , Adulto , Estudos Transversais , Diagnóstico Diferencial , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos ProspectivosRESUMO
A case of a 22-year-old young pregnant woman with palpitations and near syncope is presented. Holter monitoring showed very frequent premature beats and runs of wide complex tachycardia, refractory to antiarrhythmic drugs. Electrophysiologic evaluation disclosed spontaneous automatism arising in an atriofascicular pathway. Differential diagnosis is discussed.
Assuntos
Feixe Acessório Atrioventricular , Técnicas Eletrofisiológicas Cardíacas , Frequência Cardíaca , Complicações na Gravidez/diagnóstico , Taquicardia Ventricular/diagnóstico , Complexos Ventriculares Prematuros/diagnóstico , Potenciais de Ação , Antiarrítmicos/uso terapêutico , Resistência a Medicamentos , Eletrocardiografia Ambulatorial , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Valor Preditivo dos Testes , Gravidez , Complicações na Gravidez/tratamento farmacológico , Complicações na Gravidez/fisiopatologia , Terceiro Trimestre da Gravidez , Taquicardia Ventricular/tratamento farmacológico , Taquicardia Ventricular/fisiopatologia , Fatores de Tempo , Complexos Ventriculares Prematuros/tratamento farmacológico , Complexos Ventriculares Prematuros/fisiopatologia , Adulto JovemRESUMO
Aims: The clinical characteristics of atrial tachycardias (AT) ablated from the non-coronary aortic sinus (NCS) are thus far described only in small series. We aimed to outline, in a large cohort of patients, the clinical, electrocardiographic, electrophysiological characteristics of this tachycardia. Methods and results: We analysed data pertaining to clinical, electrocardiographic, and electrophysiological characteristics of 43 consecutive patients from an overall cohort of 441 with AT who were successfully ablated from the NCS. The tachycardias ablated from the NCS were paroxysmal (98%) and adenosine sensitive (35/35). The patients were aged 54.6 ± 12.4 years, showing female preponderance (74%). No P wave pattern was predictive of the location of ablation. Electrophysiological findings suggested a possible micro-reentrant mechanism. During tachycardia, atrial electrograms recorded in the NCS preceded the A in the His region by 10.9 ± 7.4 ms. Fractionated atrial electrograms were noted at the site of ablation in 42 patients during the tachycardia. Radiofrequency ablation terminated the tachycardia within 5 s in 88%, with thermal automaticity seen only in 3 patients. The site of ablation at the base of the NCS was adjacent to the presumed site of the retroaortic node, a remnant of the initial atrio-ventricular canal musculature. Conclusions: AT ablated from the NCS is a paroxysmal arrhythmia in middle-aged women, with distinct electrocardiographic and electrophysiological characteristics. We suspect the retroaortic node to be involved in the tachycardia circuit.
Assuntos
Ablação por Cateter/métodos , Seio Aórtico/cirurgia , Taquicardia Supraventricular/cirurgia , Potenciais de Ação , Adulto , Idoso , Idoso de 80 Anos ou mais , Brasil , Ablação por Cateter/efeitos adversos , Intervalo Livre de Doença , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Europa (Continente) , Feminino , Frequência Cardíaca , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Estudos Prospectivos , Estudos Retrospectivos , Seio Aórtico/fisiopatologia , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/fisiopatologia , Fatores de Tempo , Resultado do TratamentoRESUMO
AIMS: Unlike in the Wolff-Parkinson-White syndrome, there has been no systematic study on the role of the pre-excitation pattern in predicting the ablation site in patients with atriofascicular (AF) pathways. We assessed in a large cohort the value of the 12-lead electrocardiogram (ECG) during antidromic tachycardia (ADT) to predict the site of ablation. METHODS AND RESULTS: Forty-five patients were studied, 23 males (51%), mean age of 27 ± 12 years with 46 AF pathways and 48 ADT using the AF pathway for A-V conduction. Inclusion required induction of a sustained ADT and successful ablation. Ablation site was assessed during LAO 45° projection and clockwise classified as hours in posteroseptal, posterolateral, lateral, anterolateral, and anteroseptal tricuspid annulus as follows: 05:00-07:00, >07:00-08:00, >08:00-09:00, >09:00-11:00, and >11:00-13:00 o'clock. The QRS axis was assessed during ADT and classified as normal (>+15°), horizontal (+15° to -30°), and superior (<-30°). During ADT axis was superior (-57° ± 10°) in 15 (31%), horizontal (-11° ± 14°) in 22 (46%), and normal (+45° ± 16°) in 11 (23%) patients. The correct ablation site did not differ between the different groups of QRS axis. QRS width during ADT was narrower in patients with a normal when compared with a horizontal and leftward axis (127 ± 14 vs. 145 ± 12 ms, P < 0.0001), and the V-H interval was shorter (4 ± 3 ms vs. 19 ± 22 ms, P = 0.03). CONCLUSIONS: There was no correlation between the AF pathway ablation site and the QRS axis during ADT. The 12-lead ECG during maximal pre-excitation does not predict the proper site of tricuspid annulus ablation in patients with A-V conduction over an AF pathway.
Assuntos
Feixe Acessório Atrioventricular/diagnóstico , Feixe Acessório Atrioventricular/cirurgia , Nó Atrioventricular/cirurgia , Ablação por Cateter , Eletrocardiografia , Taquicardia/diagnóstico , Taquicardia/cirurgia , Feixe Acessório Atrioventricular/fisiopatologia , Adolescente , Adulto , Nó Atrioventricular/fisiopatologia , Brasil , Criança , Pré-Escolar , Feminino , Frequência Cardíaca , Humanos , Índia , Masculino , Pessoa de Meia-Idade , Países Baixos , Valor Preditivo dos Testes , Estudos Retrospectivos , Taquicardia/fisiopatologia , Adulto JovemAssuntos
Feixe Acessório Atrioventricular/fisiopatologia , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Taquicardia Supraventricular/diagnóstico , Feixe Acessório Atrioventricular/cirurgia , Potenciais de Ação , Adulto , Bloqueio de Ramo/diagnóstico , Bloqueio de Ramo/fisiopatologia , Estimulação Cardíaca Artificial , Ablação por Cateter , Sistema de Condução Cardíaco/cirurgia , Humanos , Masculino , Valor Preditivo dos Testes , Recidiva , Taquicardia Supraventricular/fisiopatologia , Taquicardia Supraventricular/cirurgia , Fatores de TempoRESUMO
BACKGROUND: Advancement of ventricular activation by an atrial premature beat (APB) given during His bundle refractoriness followed by resetting of an antidromic tachycardia (AT) in patients with decrementally conducting accessory pathway (DAP) is a helpful maneuver to prove pathway existence and participation in the circuit. We aim to assess in a large cohort the role of APB during AT in patients with a DAP. METHODS AND RESULTS: Thirty-three patients with a DAP having 34 AT were included in the study: 29 patients had an atriofascicular pathway, 1 had a long atrioventricular DAP, and 4 had a short atrioventricular fiber. APBs were delivered initially from the lateral right atrium, scanning diastole with a 10-ms decrement until AT termination or refractoriness. We observed 4 patterns of response after APB during AT: advancement of activation (29 cases), delay (2), advancement followed by delay (3), and termination (7). Eight patients required an earlier APB to advance or delay ventricular activation. These 8 patients had a shorter AT cycle length (median of 273 versus 315 ms; P=0.003) and had a shorter resetting zone (median coupling interval of 30 versus 50 ms; P=0.01). CONCLUSIONS: APB delivered during AT in patients with a DAP advanced and/or delayed ventricular activation in all patients. In 1 of 5 of cases the AT was terminated by a single APB. In approximately a quarter of the patients an earlier coupled APB was needed to reset AT. The high RA was an adequate stimulation site in all right-sided DAP.
Assuntos
Complexos Atriais Prematuros/etiologia , Nó Atrioventricular/fisiopatologia , Eletrocardiografia , Átrios do Coração/fisiopatologia , Frequência Cardíaca/fisiologia , Ventrículos do Coração/fisiopatologia , Taquicardia por Reentrada no Nó Atrioventricular/complicações , Adulto , Complexos Atriais Prematuros/fisiopatologia , Feminino , Seguimentos , Humanos , Masculino , Estudos Prospectivos , Taquicardia por Reentrada no Nó Atrioventricular/fisiopatologiaRESUMO
BACKGROUND: Recognition of the presence and role of decremental fibers during wide QRS tachycardia requires carefully executed intracardiac studies. OBJECTIVE: This study sought to determine the value of the atrioventricular (AV) conduction time during pre-excited tachycardia to differentiate a fast from a decrementally conducting accessory pathway (AP). METHODS: Fifty-one patients with 56 pre-excited tachycardias were included in the study: Group I: 27 patients with 31 antidromic tachycardia (ADT) using an atriofascicular pathway, Group II: 2 patients with pre-excited tachycardia due to bystander AV conduction, Group III: 3 patients with ADT and a short AV Mahaim fiber, and Group IV: 19 patients with 21 ADT using a fast conducting right-sided AP. The AV interval was measured in the His bundle electrogram and related to the tachycardia cycle length (TCL) by making an AV/TCL index. RESULTS: An AV interval > or = 150 ms during pre-excited tachycardia yielded a 91% sensitivity, 90% specificity, positive predictive value of 94%, and negative predictive value of 83% for AV conduction over a decrementally conducting pathway, whereas a > or =0.55 AV/TCL index yielded a sensitivity of 89%, specificity of 100%, positive predictive value of 100%, and negative predictive value of 84%. In 3 of 4 patients with Mahaim fibers and a <0.55 AV/TCL index, a prolonged ventriculoatrial (VA) conduction time was found. CONCLUSIONS: An AV interval > or =150 ms during pre-excited tachycardia is a fast and reliable method for detecting a decrementally conducting AP. Correcting the AV interval by the tachycardia cycle length improved specificity and positive predictive accuracy.