RESUMO
OBJECTIVE: To present the authors' experience of Mahaim-type accessory pathways (MAPs), focusing on anatomic localizations. METHODS: Data from consecutive patients who underwent electrophysiological study (EPS) for MAP ablation in two tertiary centres, between January 1998 and June 2020, were retrospectively analysed. RESULTS: Of the 55 included patients, 27 (49.1%) were male, and the overall mean age was 29.5 ± 11.6 years (range, 12-66 years). MAPs were ablated at the tricuspid annulus in 43 patients (78.2%), mitral annulus in four patients (7.3%), paraseptal region in three patients (5.5%), and right ventricle mid-apical region in five patients (9.1%). Among 49 patients who planned for ablation therapy, the success rate was 91.8% (45 patients). CONCLUSION: MAPs were most often ablated at the lateral aspect of the tricuspid annuli, sometimes at other sides of the tricuspid and mitral annuli, and infrequently in the right ventricle. The M potential mapping technique is likely to be a useful target for ablation of MAPs.
Assuntos
Ablação por Cateter , Pré-Excitação Tipo Mahaim , Adolescente , Adulto , Eletrocardiografia , Ventrículos do Coração , Humanos , Masculino , Valva Mitral , Pré-Excitação Tipo Mahaim/cirurgia , Estudos Retrospectivos , Adulto JovemRESUMO
AIMS: Mahaim-type accessory pathways (MAPs) are generally right-sided due to the embryological differentiation, but left-sided localization is also possible. This study aims to compare the clinical and electrophysiological characteristics of right- and left-sided MAPs. METHODS: Of 251 patients diagnosed with AP by electrophysiological study between November 2015 and February 2020, 12 patients with MAP were included (right sided n = 8, left sided n = 4). MAP was diagnosed if; (1) no retrograde conduction; (2) anterograde decremental conduction; (3) adenosine sensitivity; and (4) Mahaim potential at successful ablation site were present. RESULTS: Ten of twelve MAPs were clustered on the lateral walls of the mitral (n = 3, 75%) and tricuspid annuli (n = 7, 87.5%). Right-sided MAPs were mostly long pathways extending toward the conduction system whereas left-sided MAPs were short extending toward the neighboring myocardium. For right- and left-sided APs, the median QRS times were 129 and 156 ms (p = .042), the median VAbl -RVApex intervals were -12 and 64 ms (p = .007), the median QRS-V(His) intervals were 16 and 86 ms (p = .120), and the median VAbl -QRS interval was -8 and 12 ms (p = .017), respectively. Coexistence of dual atrioventricular node physiology was observed only in right-sided APs (n = 3, 37.5%). CONCLUSION: MAPs are more typically located on the right but may rarely be seen on the left. Catheter ablation was associated with high success without complications.
Assuntos
Feixe Acessório Atrioventricular , Ablação por Cateter , Pré-Excitação Tipo Mahaim , Taquicardia por Reentrada no Nó Atrioventricular , Feixe Acessório Atrioventricular/cirurgia , Eletrocardiografia , Sistema de Condução Cardíaco/cirurgia , Humanos , Pré-Excitação Tipo Mahaim/cirurgia , Taquicardia por Reentrada no Nó Atrioventricular/cirurgiaRESUMO
Mapping and ablation of atriofascicular fibers can be highly challenging due to the complex and dynamic anatomy of the tricuspid valve annulus. This case highlights the utility of a multi-electrode catheter three-dimensional mapping approach to localize the Mahaim pathway along the tricuspid annulus in order to guide catheter ablation.
Assuntos
Ablação por Cateter , Pré-Excitação Tipo Mahaim , Eletrocardiografia , Eletrodos , Humanos , Pré-Excitação Tipo Mahaim/cirurgia , Valva Tricúspide/cirurgiaAssuntos
Feixe Acessório Atrioventricular , Eletrocardiografia , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Pré-Excitação Tipo Mahaim/diagnóstico , Taquicardia/diagnóstico , Potenciais de Ação , Adolescente , Ablação por Cateter , Técnicas Eletrofisiológicas Cardíacas , Feminino , Sistema de Condução Cardíaco/cirurgia , Humanos , Pré-Excitação Tipo Mahaim/fisiopatologia , Pré-Excitação Tipo Mahaim/cirurgia , Valor Preditivo dos Testes , Taquicardia/fisiopatologia , Taquicardia/cirurgiaRESUMO
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
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 TratamentoAssuntos
Anomalia de Ebstein/diagnóstico , Pré-Excitação Tipo Mahaim/diagnóstico , Taquicardia Supraventricular/diagnóstico , Adenosina/uso terapêutico , Adulto , Antiarrítmicos/uso terapêutico , Anomalia de Ebstein/tratamento farmacológico , Fenômenos Eletrofisiológicos , Feminino , Humanos , Taquicardia Supraventricular/tratamento farmacológico , Adulto JovemAssuntos
Feixe Acessório Atrioventricular/fisiopatologia , Potenciais de Ação , Frequência Cardíaca , Pré-Excitação Tipo Mahaim/cirurgia , Feixe Acessório Atrioventricular/cirurgia , Adolescente , Ablação por Cateter , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Feminino , Humanos , Pré-Excitação Tipo Mahaim/diagnóstico , Pré-Excitação Tipo Mahaim/fisiopatologia , Fatores de Tempo , Resultado do TratamentoRESUMO
Atypical bypass tracts or variants of ventricular pre-excitation are rare anatomic structures often with rate-dependent slowing in conduction, called decremental conduction. During sinus rhythm, electrocardiographic recognition of those structures may be difficult because unlike in the Wolff-Parkinson-White syndrome where usually overt ventricular pre-excitation is present, the electrocardiogram (ECG) often shows a subtle pre-excitation pattern because of less contribution to ventricular activation over the slow and decrementally conducting bypass. Following the structure described by Ivan Mahaim and Benatt corresponding to a fasciculoventricular pathway, several other new variants of ventricular pre-excitation were reported. In this review, we aim to discuss the electrocardiographic pattern of the different subtypes of variants of ventricular pre-excitation, including the atriofascicular pathway, long and short decrementally conducting atrioventricular pathways, fasciculoventricular pathway, the atrio-Hisian bypass tract, and nodoventricular and nodofascicular fibres. Emphasis will be on the ECG findings during sinus rhythm.
Assuntos
Feixe Acessório Atrioventricular , Eletrocardiografia , Sistema de Condução Cardíaco/fisiopatologia , Frequência Cardíaca , Síndromes de Pré-Excitação/diagnóstico , Pré-Excitação Tipo Mahaim/diagnóstico , Potenciais de Ação , Adenosina/administração & dosagem , Animais , Humanos , Síndromes de Pré-Excitação/fisiopatologia , Pré-Excitação Tipo Mahaim/fisiopatologia , Valor Preditivo dos TestesRESUMO
Ebstein's anomaly is often accompanied by either Wolff-Parkinson-White syndrome or atriofascicular Mahaim. These bypass tracts give rise to antidromic atrioventricular (AV) re-entrant tachycardias, in which the bypass tract serves as the anterograde limb of the circuit and the AV node as the retrograde limb of the reentrant circuit. Since the antidromic AV reentrant tachycardia over a Mahaim fibre has a typically left bundle braunch block (LBBB) morphology, it is easy to make a misdiagnosis of supraventricular tachycardia with functional LBBB or even of ventricular tachycardia particularly in the presence of negative concordance. Some electrocardiographic clues might prevent misdiagnosis of ventricular tachycardia and inadvertent ICD implantation.
Assuntos
Anomalia de Ebstein/fisiopatologia , Eletrocardiografia , Pré-Excitação Tipo Mahaim/diagnóstico , Taquicardia por Reentrada no Nó Atrioventricular/diagnóstico , Desfibriladores Implantáveis , Diagnóstico Diferencial , Erros de Diagnóstico , Anomalia de Ebstein/complicações , Anomalia de Ebstein/cirurgia , Feminino , Humanos , Pessoa de Meia-Idade , Pré-Excitação Tipo Mahaim/etiologia , Taquicardia por Reentrada no Nó Atrioventricular/terapiaAssuntos
Mapeamento Potencial de Superfície Corporal/instrumentação , Cateteres Cardíacos , Ablação por Cateter/instrumentação , Pré-Excitação Tipo Mahaim/cirurgia , Taquicardia Supraventricular/cirurgia , Adulto , Desenho de Equipamento , Humanos , Masculino , Pré-Excitação Tipo Mahaim/fisiopatologia , Taquicardia Supraventricular/fisiopatologiaAssuntos
Feixe Acessório Atrioventricular , Adenosina/administração & dosagem , Eletrocardiografia , Pré-Excitação Tipo Mahaim/diagnóstico , Agonistas do Receptor Purinérgico P1/administração & dosagem , Potenciais de Ação , Adolescente , Erros de Diagnóstico , Frequência Cardíaca , Humanos , Pré-Excitação Tipo Mahaim/fisiopatologia , Valor Preditivo dos Testes , Reprodutibilidade dos TestesRESUMO
The atriofascicular accessory pathway (AP), known as the Mahaim pathway, is a rare form of pre-excitation, comprising less than 3% of all APs. Mahaim AP is characterized by decremental, anterograde-only conduction, and antidromic tachycardia with left bundle branch morphology. Prevalence of Mahaim AP in Ebstein's anomaly is significantly high. In addition, combination of Wolff-Parkinson-White (WPW) syndrome and Mahaim AP in patients with Ebstein's anomaly has been reported. Presently described is the coexistence of Mahaim AP and manifest WPW syndrome in a patient with Ebstein's anomaly, who was successfully ablated without fluoroscopy.