RESUMO
BACKGROUND: To investigate the clinical features of preexcitation-induced dilated cardiomyopathy in infants and evaluate safety and efficacy of radiofrequency ablation (RFCA) in these patients. METHODS: This study included 10 infants (4 males and 6 females) with mean age of 6.78±3.14 months, mean weight of 8.11±1.71 kg, and mean left ventricular ejection fraction (LVEF) was 32.6±10.34%. Tachycardiomyopathy has been excluded and all patients were refractory to the drugs. All of these 10 patients underwent RFCA. RESULTS: All the accessory pathways in these patients were located on right free wall and the acute success rate was 100%. No complication associated with the procedure occurred. In one case preexcitation recurred and was ablated successfully during the second attempt. There were 3 patients with mild cardiac dysfunction (LVEF, 40≤LVEF<50%), 3 with moderate (30≤LVEF<40%), and 4 with severe cardiac dysfunction (LVEF<30%, the ages were 3, 6, 7, and 10 months, respectively). The time for LVEF normalization was 1 week, 1 to 3 months, and ≥3 months, respectively. In 3 of the 4 severe cardiac dysfunction patients, the LVEF normalized at 3, 6, and 12 months after ablation, the LVEF of the remaining case did not recover at 3 months and is still being followed. CONCLUSIONS: Ventricular preexcitation could lead to severe cardiac dysfunction during infancy. RFCA may be a safe and effective treatment option in right free wall accessory pathways, even in infants with cardiac dysfunction. Cases of more severe cardiac dysfunction might require a longer time for LVEF recovery after RFCA.
Assuntos
Cardiomiopatia Dilatada , Ablação por Cateter , Cardiopatias , Síndromes de Pré-Excitação , Masculino , Feminino , Humanos , Lactente , Volume Sistólico , Cardiomiopatia Dilatada/diagnóstico , Cardiomiopatia Dilatada/cirurgia , Função Ventricular Esquerda , Ablação por Cateter/efeitos adversos , Síndromes de Pré-Excitação/diagnóstico , Síndromes de Pré-Excitação/cirurgia , Resultado do TratamentoRESUMO
INTRODUCTION: We describe two patients with right supero-paraseptal accessory pathway (SPAP) who developed left ventricular dysfunction associated with an increased degree of ventricular pre-excitation and frequent orthodromic reciprocating tachycardia (ORT) due to worsening atrioventricular (AV) node conduction. METHODS AND RESULTS: Case 1: 48-year-old female with a history of normally functioning mechanical mitral valve, CABG, and ventricular pre-excitation that worsened after her open heart surgery. She presented with frequent palpitations with documented supraventricular tachycardia (SVT) and found to have a new left ventricular dysfunction with decrease in left ventricular ejection fraction (LVEF) from 55% to 46% with dyssynchrony. An electrophysiological study confirmed a right SPAP and ORT. The pathway was successfully ablated from the antegrade approach after careful mapping. After ablation and 6-month follow up echocardiogram showed improvement of EF to 54% and the LV dyssynchrony resolved. Case 2: 51-year-old male with a history of frequent SVT with recent unsuccessful ablations that resulted in worsening ventricular pre-excitation, more frequent SVT, and new left ventricular dysfunction (LVEF from 60% to 40%). He was started on amiodarone which resulted in significant sinus bradycardia, intermittent ventricular pre-excitation, and first degree AV block with significant increase in ORT events. His electrophysiology study confirmed SPAP which was successfully ablated from the antegrade approach after careful mapping. After 1 month, follow-up echocardiogram showed an improved ejection fraction to 60%. CONCLUSION: Left ventricular dysfunction due to dyssynchrony and symptomatic frequent ORT of right SPAP can develop in the setting of new iatrogenic diminished AV node conduction. Successful ablation will result in LV function recovery to baseline.
Assuntos
Feixe Acessório Atrioventricular , Cardiomiopatias , Ablação por Cateter , Síndromes de Pré-Excitação , Taquicardia Paroxística , Taquicardia Reciprocante , Taquicardia Supraventricular , Disfunção Ventricular Esquerda , Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Volume Sistólico , Eletrocardiografia , Função Ventricular Esquerda , Taquicardia Paroxística/cirurgia , Síndromes de Pré-Excitação/cirurgia , Cardiomiopatias/complicações , Cardiomiopatias/cirurgia , Doença Iatrogênica , Ablação por Cateter/efeitos adversosRESUMO
Wolff-Parkinson-White syndrome, is known to cause left ventricular dysfunction or dilated cardiomyopathy secondary to sustained tachycardia in infants and children. However, left ventricular dysfunction secondary to pre-excitation related abnormal ventricular activation has been reported in a limited number of cases. This condition should be recognized early, as catheter ablation of the accessory pathway can permit rapid ventricular function improvement. In this paper, we present a 2.5-year-old patient diagnosed with tachycardia-free Wolff-Parkinson-White syndrome with a right free wall accessory pathway and depressed cardiac function, whose left ventricular function is completely restored after successful catheter cryoablation.
Assuntos
Ablação por Cateter , Síndromes de Pré-Excitação , Disfunção Ventricular Esquerda , Síndrome de Wolff-Parkinson-White , Lactente , Criança , Humanos , Pré-Escolar , Síndrome de Wolff-Parkinson-White/complicações , Síndrome de Wolff-Parkinson-White/diagnóstico , Síndrome de Wolff-Parkinson-White/cirurgia , Eletrocardiografia , Resultado do Tratamento , Síndromes de Pré-Excitação/complicações , Síndromes de Pré-Excitação/diagnóstico , Síndromes de Pré-Excitação/cirurgia , Ablação por Cateter/efeitos adversosRESUMO
BACKGROUND: Wolff-Parkinson-White (WPW) concomitant with atrial tachyarrhythmia (ATA) has not been systemically characterized. METHODS: Detailed electroanatomical mapping of the right atrium (RA) and/or left atrium (LA) was performed using three-dimensional mapping and the accessory pathway (AP) was mapped. RESULTS: WPW syndrome with ATA was diagnosed in 11 patients (median age 60 years). The characteristic of unidirectional anterograde conduction over the AP was displayed in nine patients, six of whom were intermittent. Sustained atrial tachycardia, that is, counterclockwise atrial flutter (AFL) with a median tachycardia cycle length (TCL) of 225 (220-275) ms, was mapped in eight patients; furthermore, "figure 8" right atrial reentry was mapped with TCL 250 ms in one patient with a surgical history of ventricular septal defect repair. The remaining two patients underwent mitral annulus-dependent AT after paroxysmal atrial fibrillation (PAF) ablation and LA micro-reentry AT, respectively. In four patients, the location of the APs was left posterior. Left-lateral APs were identified in four patients. The locations of the APs in the remaining three patients were the right posterior and middle septum. All ATAs and APs were successfully ablated. After a median follow-up of 37 (15-72) months, no anterograde conduction over the AP was recorded, new onset of PAF was recorded in three patients, and all of them underwent circumferential pulmonary vein isolation. CONCLUSIONS: WPW with concomitant ATA frequently had continuous anterograde conduction over the AP with a rapid ventricular rate. Most WPWs displayed the characteristic of unidirectional anterograde conduction.
Assuntos
Síndromes de Pré-Excitação , Humanos , Pessoa de Meia-Idade , Síndromes de Pré-Excitação/complicações , Síndromes de Pré-Excitação/diagnóstico , Síndromes de Pré-Excitação/cirurgia , Átrios do Coração/cirurgiaAssuntos
Feixe Acessório Atrioventricular , Ablação por Cateter , Síndromes de Pré-Excitação , Síndrome de Wolff-Parkinson-White , Feixe Acessório Atrioventricular/cirurgia , Ablação por Cateter/efeitos adversos , Criança , Eletrocardiografia , Humanos , Desempenho Físico Funcional , Projetos Piloto , Síndromes de Pré-Excitação/diagnóstico , Síndromes de Pré-Excitação/cirurgia , Síndrome de Wolff-Parkinson-White/diagnóstico , Síndrome de Wolff-Parkinson-White/cirurgiaRESUMO
BACKGROUND: Pre-excited atrial fibrillation (AF) is associated with increased risk of life-threatening events. However, at times, patients with pre-excited AF still repetitively suffer from hemodynamic disturbance, with resistance to acute treatments of antiarrhythmic therapy and cardioversion. METHODS: To evaluate the feasibility in correcting hemodynamic disturbance, patients with pre-excited AF who underwent catheter ablation of accessory pathway as an emergency procedure, were retrospectively collected from two centers of China. The medical records of patients were analyzed and summarized in this case series. RESULTS: Five patients with pre-excited AF who received emergency catheter ablation of accessory pathway, were collected from two contributor centers and reported in this case series. All collected patients still repetitively suffered from hemodynamic disturbance induced by rapid anterograde conduction of AF via pathway, even guideline recommended acute interventions of intravenous antiarrhythmic therapy and cardioversion had been performed. Finally, as an emergency procedure, catheter ablation of accessory pathway was performed in collected patients. Correspondingly, the hemodynamic unstable status was greatly relieved. Meanwhile, all collected patients with high risk of pre-excited AF were combined with left-sided accessory pathway, with shortest RR interval of widened pre-excited QRS complex less than 250 ms. Thus, combination with left-sided pathway is proposed as an indicator for the increased risk of life-threatening events in patients with high risk of pre-excited AF. CONCLUSIONS: Emergency catheter ablation of accessory pathway is an effective option for the acute managements of patients with high risk of pre-excited AF in unstable hemodynamics, which is resistant to antiarrhythmic therapy and cardioversion.
Assuntos
Feixe Acessório Atrioventricular , Fibrilação Atrial , Ablação por Cateter , Síndromes de Pré-Excitação , Síndrome de Wolff-Parkinson-White , Feixe Acessório Atrioventricular/cirurgia , Antiarrítmicos , Fibrilação Atrial/etiologia , Fibrilação Atrial/cirurgia , Ablação por Cateter/métodos , Humanos , Síndromes de Pré-Excitação/cirurgia , Estudos RetrospectivosRESUMO
BACKGROUND: Localization of atrioventricular accessory pathways (AP) from Electrocardiogram (ECG) is crucial for successful ablation. We analyzed the value of limb lead 2 versus 3 QRS vector discordance on surface ECG among right-sided pathways. METHODS: Data from consecutive patients undergoing successful ablation of manifest AP were analyzed. They were categorized into two groups-Gr I: Endocardial ablation from anterior and anterolateral tricuspid annulus (TA, 10-1 o'clock, right anterolateral [RAL]); Gr II: Ablation outside this region (1-10 o'clock of TA). Inferior lead discordance (ILD) was defined as positive QRS complex (monophasic R, Rs) in lead 2 with negative/equiphasic QRS vector in lead 3 (rS, S, RS). Maximally pre-excited ECGs during electrophysiology study were compared for presence of ILD. RESULT: Among total 22 cases (Age 36 ± 18 years, 12 males), ILD was noted in 4/4 cases of Gr I. It was absent among 17/18 cases of right-sided AP in Gr II. The only case in Gr II having ILD was ablated near 8 o'clock (posterolateral). In contrast to the other four cases, aVF was negative, along with lead 3. A close differential was mid-septal AP (MSAP). However, the MSAP had absence of r in V1 and lead 2 having rS/RS complex in contrast to strongly positive QRS in RAL pathways. The sensitivity and specificity of ILD for RAL are 100% and 95%, respectively. The positive, negative predictive value, and accuracy are 80%, 100%, and 95%, respectively. CONCLUSION: Positive QRS complex in lead 2 with negative QRS in lead 3 in maximally pre-excited ECG is often predictive of anterior and anterolateral location among right-sided pathways.
Assuntos
Feixe Acessório Atrioventricular , Ablação por Cateter , Síndromes de Pré-Excitação , Síndrome de Wolff-Parkinson-White , Feixe Acessório Atrioventricular/diagnóstico , Feixe Acessório Atrioventricular/cirurgia , Adolescente , Adulto , Fascículo Atrioventricular , Eletrocardiografia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes de Pré-Excitação/cirurgia , Adulto JovemRESUMO
BACKGROUND: Fasciculoventricular pathways (FVPs) are variants of pre-excitation syndrome which were investigated insufficiently because of its rarity. OBJECTIVE: This report aimed to represent one of the largest series of FVP, focusing on its clinical and electrophysiological properties. METHODS: We analyzed retrospectively 26 consecutive patients who underwent electrophysiological study (EPS) for FVP between January 1998 and June 2020. RESULTS: Among 1437 patients with accessory pathways, 26 had FVP (1.80%). All the 26 patients (100%) were males, with a mean age of 22.15 ± 3.50 years (range, 20-34 years). In the baseline electrocardiograms of the patients with FVP, pre-excitation and transitional zone were seen in leads V2 -V4 . During EPS procedures, normal AH interval and shortened HV interval were detected. All the patients had AH prolongation after atrial pacing due to atrioventricular (AV) nodal delay without change in pre-excitation degree. Five of the FVP patients (19.2%) had extra accessory pathways, all of which were ablated successfully while the FVPs were followed clinically. CONCLUSION: Fasciculoventricular pathways are uncommon variants of pre-excitation syndrome; therefore, they should be diagnosed correctly and followed up noninvasively to avoid damages.
Assuntos
Feixe Acessório Atrioventricular , Síndromes de Pré-Excitação , Feixe Acessório Atrioventricular/cirurgia , Adolescente , Adulto , Nó Atrioventricular , Eletrocardiografia , Feminino , Humanos , Masculino , Síndromes de Pré-Excitação/diagnóstico , Síndromes de Pré-Excitação/cirurgia , Estudos Retrospectivos , Adulto JovemRESUMO
BACKGROUND: In contrast to adults, in whom cardiac rhythm disorders are mainly conditioned by coronary artery disease, in children, arrhythmias are most often associated with inherited heart disorders. Catheter ablation (CA) has an important role in the management of cardiac arrhythmias, in adults and children. The aim of the study was to assess and compare the efficacy and safety of CA in children and adults with preexcitation syndrome. METHODS: The study population comprised 43 adults and 43 children diagnosed with a Wolff-Parkinson-White syndrome (WPW). The mean age of the study population was 41 ± 15 years for adults and 14 ± 2.5 years for children. In all patients, an electrophysiological study and CA were performed. Analysis with respect to the procedure duration, fluoroscopy exposure time, location of accessory pathways (AP), immediate success rate and complications were performed. RESULTS: Electrophysiological study revealed the most frequent presence of left-sided AP (56% in children and 70% in adults). The mean procedure duration was 96 ± 36 min and 106 ± 51 min in children and adults, respectively (p = NS). The mean fluoroscopy duration was 8.5 ± 4.3 min and 5.9 ± 5.8 min in children and adults, respectively p < 0.05. The CA procedure was successful in 40 out of 43 (93%) adults and in 36 out of 43 (83.7%) children (p = NS). In 2 (4%) children minor complications occurred. CONCLUSIONS: Ablation in children and adults are equally effective with respect to short-term clinical observation.
Assuntos
Feixe Acessório Atrioventricular , Ablação por Cateter , Síndromes de Pré-Excitação , Síndrome de Wolff-Parkinson-White , Feixe Acessório Atrioventricular/cirurgia , Adulto , Arritmias Cardíacas/complicações , Arritmias Cardíacas/diagnóstico , Arritmias Cardíacas/cirurgia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Criança , Humanos , Pessoa de Meia-Idade , Síndromes de Pré-Excitação/complicações , Síndromes de Pré-Excitação/diagnóstico , Síndromes de Pré-Excitação/cirurgia , Resultado do Tratamento , Síndrome de Wolff-Parkinson-White/complicações , Síndrome de Wolff-Parkinson-White/diagnóstico , Síndrome de Wolff-Parkinson-White/cirurgiaRESUMO
A 55-year-old male presented with acute heart failure and incessant wide complex tachycardia resembling an outflow tract ventricular tachycardia. Meticulous analysis of the electrocardiograms established the diagnosis of pre-excitation with prolonged atrio-ventricular (A-V) conduction over a decrementally conducting accessory A-V pathway. "Linking" between the accessory A-V pathway and normal A-V conduction system resulted in sustained maximal pre-excitation as well as periodic transition to normal A-V conduction without appreciable change in heart rate. Successful radiofrequency ablation of this unusual accessory A-V pathway was performed at the aortic-mitral junction. This ameliorated the mechanical dysynchrony, allowed discontinuation of hemodynamic/inotropic support, and resulted in sustained symptomatic improvement.
Assuntos
Eletrocardiografia , Síndromes de Pré-Excitação/diagnóstico , Cardiomiopatias/fisiopatologia , Cardiomiopatias/cirurgia , Ablação por Cateter , Diagnóstico Diferencial , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes de Pré-Excitação/fisiopatologia , Síndromes de Pré-Excitação/cirurgia , Taquicardia/fisiopatologia , Taquicardia/cirurgiaRESUMO
Management of asymptomatic subjects with preexcitation remains controversial. Our objective was to analyze the reasons an electrophysiological study (EPS) was performed in an asymptomatic population referred for the procedure, and compare the results of catheter ablation between asymptomatic and symptomatic patients. Patients ≥18 years of age with preexcitation referred for an EPS and ablation were grouped as either symptomatic or asymptomatic. We analyzed in both subsets for (1) reasons for the procedure, (2) EPS results (anterograde effective refractory period of the accessory pathway, tachycardia/atrial fibrillation inducibility, anatomical localization), (3) success of the procedure, and (4) incidence of complications. We included 175 patients, 121 of which were symptomatic (39 ± 16 years) and 54 were asymptomatic (35 ± 14 years, pâ¯=â¯NS not significant). The most frequent symptoms were palpitations (87%) and syncope (7%). EPS was performed in 44 of 54 asymptomatic patients mainly because of involvement in sports (60%) or high-risk employment (14%). Anterograde effective refractory period was significantly longer in asymptomatic patients (314 ± 55 milliseconds) than in symptomatic patients (278 ± 46 milliseconds; p <0.001). Orthodromic tachycardia inducibility was significantly higher in symptomatic than in asymptomatic patients (69% and 27%, respectively; p <0.001). A total of 170 accessory pathways (49% left free wall, 12% right free wall, 39% septal) were observed without significant differences in the anatomical location between groups. Catheter ablation was attempted in all patients, succeeding in 98% of symptomatic and 95% of asymptomatic patients, without major complications in either group. In conclusion, the reasons for invasive evaluation of asymptomatic patients with preexcitation may be outside the scope of current guidelines. Catheter ablation produces excellent results without major complications.
Assuntos
Doenças Assintomáticas , Ablação por Cateter/métodos , Sistema de Condução Cardíaco/fisiopatologia , Síndromes de Pré-Excitação/cirurgia , Adulto , Eletrocardiografia , Feminino , Humanos , Masculino , Síndromes de Pré-Excitação/fisiopatologia , Resultado do TratamentoRESUMO
Block in accessory pathway (AP) conduction with adenosine has been previously described. However, conduction characteristics of these APs has not been well defined to date. All patients with APs = 21 years old who underwent an EP study from 2014 to 2017 were included in our study. Patients with adenosine sensitive APs were identified (group 1). Demographic and AP conduction characteristics were compared between group 1 and the entire cohort of patients. Local atrioventricular (AV) or ventriculoatrial (VA) time, cycle length and need for isoproterenol were compared to a control group matched by age and AP location (group 2). Student's t test, Wilcoxon rank sum, χ2 and Fisher's exact were used for analysis. Fourteen (7%) out of 207 patients had an adenosine sensitive AP. The median age of patients with adenosine sensitive APs was 11.8 (IQR 8.5-13.5) years vs. 14 (IQR 10.6-16.7) for the rest of the cohort (p = 0.04). Three of the 134 patients with preexcitation had adenosine sensitive APs (2%) vs. 11 of the 73 patients with concealed APs (15%) (p = 0.001). The median local AV/VA time at the site of successful ablation was longer in group 1 vs group 2 [78 ms, IQR 62-116 vs. 31 ms, IQR 30-38; p < 0.001]. Antegrade AP effective refractory period and total procedure time were longer in patients with adenosine sensitive APs (p = 0.03 & p = 0.04, respectively). Adenosine sensitive APs which occur in children are more often concealed. These APs have a longer conduction time at the site of successful ablation.
Assuntos
Feixe Acessório Atrioventricular/cirurgia , Adenosina/farmacologia , Ablação por Cateter/métodos , Eletrocardiografia/métodos , Frequência Cardíaca/fisiologia , Síndromes de Pré-Excitação/cirurgia , Feixe Acessório Atrioventricular/tratamento farmacológico , Feixe Acessório Atrioventricular/fisiopatologia , Adolescente , Antiarrítmicos/farmacologia , Criança , Feminino , Frequência Cardíaca/efeitos dos fármacos , Humanos , Masculino , Síndromes de Pré-Excitação/fisiopatologiaRESUMO
A 45-year-old lady was evaluated for recurrent episodes of palpitation. Her 12lead electrocardiogram (ECG) showed manifest but incomplete pre-excitation consistent with left sided accessory pathway. There was no structural heart disease by echocardiogram. She underwent an electrophysiology (EP) study after informed consent. A narrow QRS tachycardia consistent with orthodromic AV re-entry got induced. The accessory pathway was mapped to 2 'O clock of the mitral annulus (MA). While radio frequency ablation (RFA) was being performed at that site, an interesting phenomenon was observed (Figs. 1 & 2). What is the mechanism?
Assuntos
Feixe Acessório Atrioventricular , Ablação por Cateter , Síndromes de Pré-Excitação , Ablação por Radiofrequência , Feixe Acessório Atrioventricular/cirurgia , Eletrocardiografia , Feminino , Humanos , Pessoa de Meia-Idade , Síndromes de Pré-Excitação/diagnóstico , Síndromes de Pré-Excitação/cirurgiaRESUMO
Despite extensive knowledge of the physiopathology of ventricular pre-excitation, management of asymptomatic patients with this condition remains controversial.
Assuntos
Doenças Assintomáticas , Morte Súbita Cardíaca , Síndromes de Pré-Excitação , Ablação por Cateter , Eletrocardiografia , Técnicas Eletrofisiológicas Cardíacas , Humanos , Síndromes de Pré-Excitação/cirurgiaAssuntos
Fibrilação Atrial/diagnóstico , Técnicas Eletrofisiológicas Cardíacas , Sistema de Condução Cardíaco/fisiopatologia , Síndromes de Pré-Excitação/diagnóstico , Taquicardia/diagnóstico , Potenciais de Ação , Idoso , Fibrilação Atrial/fisiopatologia , Fibrilação Atrial/cirurgia , Estimulação Cardíaca Artificial , Ablação por Cateter , Diagnóstico Diferencial , Eletrocardiografia , Feminino , Sistema de Condução Cardíaco/cirurgia , Frequência Cardíaca , Humanos , Síndromes de Pré-Excitação/fisiopatologia , Síndromes de Pré-Excitação/cirurgia , Valor Preditivo dos Testes , Taquicardia/fisiopatologia , Taquicardia/cirurgia , Taquicardia Supraventricular/diagnóstico , Taquicardia Supraventricular/fisiopatologia , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/fisiopatologia , Fatores de Tempo , Resultado do TratamentoRESUMO
We reported a 57-year-old female patient who had functionally corrected transposition of the great arteries, severe tricuspid insufficiency, enlarged left atrium and functional right ventricle, which were successfully performed radiofrequency ablation.
Assuntos
Procedimentos Cirúrgicos Cardiovasculares , Síndromes de Pré-Excitação , Ablação por Radiofrequência , Transposição dos Grandes Vasos , Feminino , Humanos , Pessoa de Meia-Idade , Procedimentos Cirúrgicos Cardiovasculares/métodos , Eletrocardiografia , Coração/diagnóstico por imagem , Processamento de Imagem Assistida por Computador , Síndromes de Pré-Excitação/diagnóstico por imagem , Síndromes de Pré-Excitação/etiologia , Síndromes de Pré-Excitação/cirurgia , Tomografia Computadorizada por Raios X , Transposição dos Grandes Vasos/complicações , Transposição dos Grandes Vasos/diagnóstico por imagem , Transposição dos Grandes Vasos/cirurgia , Resultado do TratamentoRESUMO
BACKGROUND: Nodofascicular and nodoventricular (NFV) accessory pathways connect the atrioventricular node and the Purkinje system or ventricular myocardium, respectively. Concealed NFV pathways participate as the retrograde limb of supraventricular tachycardia (SVT). Manifest NFV pathways can comprise the anterograde limb of wide-complex SVT but are quite rare. The purpose of this report is to highlight the electrophysiological properties and sites of ablation for manifest NFV pathways. METHODS: Eight patients underwent electrophysiology studies for wide-complex tachycardia (3), for narrow-complex tachycardia (1), and preexcitation (4). RESULTS: NFV was an integral part of the SVT circuit in 3 patients. Cases 1 to 2 were wide-complex tachycardia because of manifest NFV SVT. Case 3 was a bidirectional NFV that conducted retrograde during concealed NFV SVT and anterograde causing preexcitation during atrial pacing. NFV was a bystander during atrioventricular node re-entrant tachycardia, atrial fibrillation, atrial flutter, and orthodromic atrioventricular re-entrant tachycardia in 4 cases and caused only preexcitation in 1. Successful NFV ablation was achieved empirically in the slow pathway region in 1 case. In 5 cases, the ventricular insertion was mapped to the slow pathway region (2 cases) or septal right ventricle (3 cases). The NFV was not mapped in cases 5 and 7 because of its bystander role. QRS morphology of preexcitation predicted the right ventricle insertion sites in 4 of the 5 cases in which it was mapped. During follow-up, 1 patient noted recurrent palpitations but no documented SVT. CONCLUSIONS: Manifest NFV may be critical for wide-complex tachycardia/manifest NFV SVT, act as the retrograde limb for narrow-complex tachycardia/concealed NFV SVT, or cause bystander preexcitation. Ablation should initially target the slow pathway region, with mapping of the right ventricle insertion site if slow pathway ablation is not successful. The QRS morphology of maximal preexcitation may be helpful in predicting successful right ventricle ablation site.
Assuntos
Feixe Acessório Atrioventricular/fisiopatologia , Nó Atrioventricular/fisiopatologia , Fascículo Atrioventricular/fisiopatologia , Ablação por Cateter/métodos , Síndromes de Pré-Excitação/cirurgia , Taquicardia por Reentrada no Nó Atrioventricular/cirurgia , Feixe Acessório Atrioventricular/cirurgia , Adulto , Idoso , Nó Atrioventricular/cirurgia , Fascículo Atrioventricular/cirurgia , Criança , Eletrocardiografia , Feminino , Átrios do Coração/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , Síndromes de Pré-Excitação/fisiopatologia , Taquicardia por Reentrada no Nó Atrioventricular/fisiopatologia , Adulto JovemRESUMO
The famous quotation of Winston Churchill, made in his radio broadcast of 1939 regarding Russia's next move, specifically "A riddle wrapped up in a mystery, inside an enigma," perfectly fits the current understanding of unusual accessory atrioventricular pathways, including the variants producing ventricular pre-excitation. It was many decades after their original descriptions that we came better to begin to understand most of their structure-function relationships. Their mysterious pathophysiology was sometimes unveiled after invasive treatments, such as surgical ablation of the atrioventricular conduction axis instead of the accessory pathway itself. Speculations made on this basis have largely been validated by subsequent clinical experience. Most of the names suggested for description of the pathways have stood well the test of time. For some of them, however, this is not the case, with the initial names becoming confusing. In a series of reviews, we re-visit those accessory pathways producing ventricular pre-excitation other than classical Wolff-Parkinson-White syndrome. To set the scene, in this initial review, we describe the development and anatomy of the normal atrioventricular conduction axis, along with the insulating tissues of the atrioventricular junctions. We have sought to illustrate our explanations by using virtual dissection of computerized tomographic datasets, since they retain the intact heart within the setting of the body. These images illustrate well the value of attitudinally appropriate terminology. Thereafter, we discuss the electrophysiological manifestations of the abnormal anatomical pathways which provide the potential for both accessory atrioventricular and intraventricular conduction.
Assuntos
Nó Atrioventricular/anormalidades , Síndromes de Pré-Excitação/patologia , Terminologia como Assunto , Técnicas de Ablação , Potenciais de Ação , Nó Atrioventricular/fisiopatologia , Nó Atrioventricular/cirurgia , Frequência Cardíaca , Humanos , Síndromes de Pré-Excitação/classificação , Síndromes de Pré-Excitação/fisiopatologia , Síndromes de Pré-Excitação/cirurgia , PrognósticoRESUMO
The rising utilization of screening electrocardiograms has resulted in increased incidental identification of ventricular pre-excitation in pediatric patients. We compared accessory pathways of incidentally identified pre-excitation to Wolff-Parkinson-White Syndrome (WPW) with the aim to identify factors important in preprocedural counseling and planning. This single-center, retrospective study of patients ≤18 years without congenital heart disease identified 227 patients diagnosed with pre-excitation and referred for invasive electrophysiology study between 2008 and 2017. WPW Syndrome was diagnosed in 178 patients, while 49 patients had incidental identification of pre-excitation. Anterograde conduction of incidentally identified accessory pathways was not clinically different between the two cohorts at baseline or upon isoproterenol infusion. However, the proportion of accessory pathways meeting high-risk criteria was significantly lower than in patients diagnosed with WPW, 12% versus 28% (p < 0.05). Retrograde conduction at baseline of incidentally diagnosed accessory pathways was slower with a median block cycle length 365 milliseconds (IQR 260 to 450) versus 290 milliseconds (IQR 260 to 330, p < 0.01). In the incidentally identified cohort, right-sided, paraHisian, and fascicular pathways were more common with fewer attempted ablations (71% vs 94%, p < 0.001) and lower success rate (91% vs 97%, p < 0.001). A binomial logistic regression analysis further indicated patients incidentally identified with pre-excitation were associated with having lower rates of inducible supraventricular tachycardia, atrial fibrillation, and ablations performed, in addition, to having right-sided pathways. In conclusion, as patients with incidentally identified pre-excitation present more frequently for consideration of invasive electrophysiology study, these results impact procedural approaches, technical considerations, patient counseling, and outcome expectations.