Assuntos
Ablação por Cateter , Comunicação Interventricular , Taquicardia Ventricular , Humanos , Taquicardia Ventricular/cirurgia , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/fisiopatologia , Ablação por Cateter/efeitos adversos , Ablação por Cateter/métodos , Comunicação Interventricular/cirurgia , Masculino , Eletrocardiografia , Feminino , Pessoa de Meia-IdadeRESUMO
BACKGROUND: Symptomatic pulmonary cement embolism in patients undergoing thoracic transpedicular fenestrated screw placement is rare. Here, we have added a 64-year-old female undergoing transpedicular screw placement for a T11 fracture who developed a pulmonary cement embolism intraoperatively and add this case to 13 others identified in the literature. CASE DESCRIPTION: A 64-year-old female presented with a type "C", ASIA "E" T11 fracture. The thoracolumbar pedicle screw fixation was supplemented with bone cement due to her underlying severe osteoporosis. During the fluoroscopy-guided supplementation with bone cement, a leak through the paravertebral venous system was noted. Thirty minutes later, the patient acutely developed extreme respiratory failure and required mechanical ventilation for the next 2 days. The diagnosis of pulmonary embolism due to bone cement was confirmed on a contrast computed tomography study of the chest. CONCLUSION: Symptomatic pulmonary cement embolization supplementing transpedicular screws placement for osteoporotic bone is rare. Here, we present a 64-year-old female who during transpedicular fixation of a T11 fracture developed an acute pulmonary embolism from the bone cement resulting in the need for 2 days of postoperative artificial ventilation.
RESUMO
BACKGROUND: Interatrial septal tachycardias (IAS-ATs) following atrial fibrillation (AF) ablation or cardiac surgery are rare, and their management is challenging. OBJECTIVE: The purpose of this study was to investigate the electrophysiological features and outcomes associated with catheter ablation of IAS-AT. METHODS: We screened 338 patients undergoing catheter ablation of ATs following AF ablation or cardiac surgery. Diagnosis of IAS-AT was based on activation mapping and analysis of response to atrial overdrive pacing. RESULTS: Twenty-nine patients (9%) had IAS-AT (cycle length [CL] 311 ± 104 ms); 16 (55%) had prior AF ablation procedures (median 3; range 1-5), 3 (10%) had prior surgical maze, and 12 (41%) had prior cardiac surgery (including atrial septal defect surgical repair in 5 and left atrial myxoma resection in 1). IAS substrate abnormalities were documented in all patients. Activation mapping always demonstrated a diffuse early IAS breakout with centrifugal biatrial activation, and atrial overdrive pacing showed a good postpacing interval (equal or within 25 ms of the AT CL) only at 1 or 2 anatomically opposite IAS sites in all cases. Ablation was acutely successful in 27 patients (93%) (from only the right IAS in 2, only the left IAS in 9, both IAS sides with sequential ablation in 13, and both IAS sides with bipolar ablation in 3). After median follow-up of 15 (6-52) months, 17 patients (59%) remained free from recurrent arrhythmias. CONCLUSION: IAS-ATs are rare and typically occur in patients with evidence of IAS substrate abnormalities and prior cardiac surgery. Catheter ablation can be challenging and may require sequential unipolar ablation or bipolar ablation.
Assuntos
Fibrilação Atrial/cirurgia , Eletrofisiologia Cardíaca/métodos , Procedimentos Cirúrgicos Cardíacos/efeitos adversos , Ablação por Cateter/efeitos adversos , Frequência Cardíaca/fisiologia , Complicações Pós-Operatórias/etiologia , Taquicardia/etiologia , Idoso , Fibrilação Atrial/fisiopatologia , Septo Interatrial/cirurgia , Feminino , Seguimentos , Humanos , Masculino , Complicações Pós-Operatórias/diagnóstico , Complicações Pós-Operatórias/fisiopatologia , Estudos Retrospectivos , Taquicardia/fisiopatologia , Fatores de TempoRESUMO
AIMS: To develop quality indicators (QIs) that may be used to evaluate the quality of care and outcomes for adults with atrial fibrillation (AF). METHODS AND RESULTS: We followed the ESC methodology for QI development. This methodology involved (i) the identification of the domains of AF care for the diagnosis and management of AF (by a group of experts including members of the ESC Clinical Practice Guidelines Task Force for AF); (ii) the construction of candidate QIs (including a systematic review of the literature); and (iii) the selection of the final set of QIs (using a modified Delphi method). Six domains of care for the diagnosis and management of AF were identified: (i) Patient assessment (baseline and follow-up), (ii) Anticoagulation therapy, (iii) Rate control strategy, (iv) Rhythm control strategy, (v) Risk factor management, and (vi) Outcomes measures, including patient-reported outcome measures (PROMs). In total, 17 main and 17 secondary QIs, which covered all six domains of care for the diagnosis and management of AF, were selected. The outcome domain included measures on the consequences and treatment of AF, as well as PROMs. CONCLUSION: This document defines six domains of AF care (patient assessment, anticoagulation, rate control, rhythm control, risk factor management, and outcomes), and provides 17 main and 17 secondary QIs for the diagnosis and management of AF. It is anticipated that implementation of these QIs will improve the quality of AF care.
Assuntos
Fibrilação Atrial , Adulto , Comitês Consultivos , Fibrilação Atrial/diagnóstico , Fibrilação Atrial/terapia , Humanos , Indicadores de Qualidade em Assistência à Saúde , Fatores de Risco , Revisões Sistemáticas como AssuntoRESUMO
COVID-19 infection has shown rapid growth worldwide, and different therapies have been proposed for treatment, in particular, the combination of immune response modulating drugs such as chloroquine and hydroxychloroquine (antimalarials) alone or in combination with azithromycin. Although the clinical evidence supporting their use is scarce, the off label use of these drugs has spread very quickly in face of the progression of the epidemic and the high mortality rate in susceptible populations. However, these medications can pathologically prolong the QT interval and lead to malignant ventricular arrhythmias such that organized guidance on QT evaluation and management strategies are important to reduce morbidity associated with the potential large-scale use.
Assuntos
Antimaláricos/efeitos adversos , Infecções por Coronavirus/tratamento farmacológico , Eletrocardiografia , Síndrome do QT Longo/induzido quimicamente , Síndrome do QT Longo/diagnóstico por imagem , Pneumonia Viral/tratamento farmacológico , Guias de Prática Clínica como Assunto , Adulto , Idoso , Antimaláricos/administração & dosagem , Arritmias Cardíacas/induzido quimicamente , Arritmias Cardíacas/epidemiologia , Azitromicina/administração & dosagem , Azitromicina/efeitos adversos , COVID-19 , Cloroquina/administração & dosagem , Cloroquina/efeitos adversos , Infecções por Coronavirus/diagnóstico , Infecções por Coronavirus/epidemiologia , Relação Dose-Resposta a Droga , Feminino , Humanos , Hidroxicloroquina/administração & dosagem , Hidroxicloroquina/efeitos adversos , Incidência , Masculino , Pessoa de Meia-Idade , Pandemias/prevenção & controle , Pandemias/estatística & dados numéricos , Pneumonia Viral/diagnóstico , Pneumonia Viral/epidemiologia , Prognóstico , Medição de Risco , Tratamento Farmacológico da COVID-19RESUMO
COVID-19 is a rapidly evolving public health emergency that has largely impacted the provision of healthcare services around the world. The challenge for electrophysiology teams is double; on one side preventing disease spread by limiting all nonessential face-to-face interactions, but at the same time ensuring continued care for patients who need it. These guidelines contain recommendations regarding triaging in order to define what procedures, device checks and clinic visits can be postponed during the pandemic. We also discuss best practices to protect patients and healthcare workers and provide guidance for the management of COVID-19 patients with arrhythmic conditions.
Assuntos
Arritmias Cardíacas/cirurgia , Ablação por Cateter/estatística & dados numéricos , Infecções por Coronavirus/prevenção & controle , Atenção à Saúde , Técnicas Eletrofisiológicas Cardíacas/normas , Pandemias/prevenção & controle , Pneumonia Viral/prevenção & controle , Guias de Prática Clínica como Assunto , Argentina , Arritmias Cardíacas/diagnóstico , Brasil , COVID-19 , Eletrofisiologia Cardíaca/organização & administração , Ablação por Cateter/normas , Colômbia , Infecções por Coronavirus/epidemiologia , Procedimentos Cirúrgicos Eletivos/normas , Procedimentos Cirúrgicos Eletivos/estatística & dados numéricos , Técnicas Eletrofisiológicas Cardíacas/estatística & dados numéricos , Feminino , Humanos , Controle de Infecções/organização & administração , América Latina , Masculino , México , Pandemias/estatística & dados numéricos , Pneumonia Viral/epidemiologia , Gestão da Segurança/normas , Sociedades MédicasRESUMO
OBJECTIVES: This study describes the use of septal coronary venous mapping to facilitate substrate characterization and ablation of intramural septal ventricular arrhythmia (VA). BACKGROUND: Intramural septal VA represents a challenge for substrate definition and catheter ablation. METHODS: Between 2015 and 2018, 12 patients with structural heart disease, recurrent VA, and suspected intramural septal substrate underwent a septal coronary venous procedure in which mapping was performed by advancement of a wire into the septal perforator branches of the anterior interventricular vein. A total of 5 patients with idiopathic VA were also included as control subjects to compare substrate characteristics. RESULTS: Patients were 63 ± 14 years of age, and 11 (92%) were men. Most patients with structural heart disease had nonischemic cardiomyopathy (83%). Six patients underwent ablation for premature ventricular contractions (PVC) and 6 for ventricular tachycardia. All patients had larger septal unipolar voltage abnormalities than bipolar voltage abnormalities (mean area 35.3 ± 16.8 cm2 vs. 10.7 ± 8.4 cm2, respectively; p = 0.01), Patients with idiopathic VA had normal voltage. Septal coronary venous mapping revealed low-voltage, fractionated, and multicomponent electrograms in sinus rhythm in all patients with substrate compared to that in patients with idiopathic VA (amplitude 0.9 ± 0.9 mV vs. 4.4 ± 3.7 mV, respectively; p = 0.007; and duration 147 ± 48 ms vs. 92 ± 10 ms, respectively; p = 0.03). Ablation targeted early activation, pace map match, and/or good entrainment sites from intraseptal recording. Over a mean follow-up of 339 ± 240 days, the PVC and insertable cardioverter-defibrillator therapies burden were significantly reduced (from a mean of 22 ± 11% to 4 ± 8%; p = 0.005; and a mean 5 ± 2 to 1 ± 1; p = 0.001, respectively). Most patients (80%) with idiopathic VA remained arrhythmia free. CONCLUSIONS: In patients with suspected intramural septal VA, mapping of the septal coronary veins may be helpful to characterize the arrhythmia substrate, identify ablation targets, and guide endocardial ablation.
Assuntos
Ablação por Cateter/métodos , Técnicas Eletrofisiológicas Cardíacas/métodos , Septos Cardíacos/fisiologia , Taquicardia Ventricular/cirurgia , Complexos Ventriculares Prematuros/cirurgia , Idoso , Eletrocardiografia , Feminino , Septos Cardíacos/diagnóstico por imagem , Humanos , Masculino , Pessoa de Meia-Idade , Estudos RetrospectivosRESUMO
BACKGROUND: Imaging guidance for left atrial appendage (LAA) closure (LAAC) conventionally consists of transesophageal echocardiography (TEE) and fluoroscopy under general anesthesia (GA). Intracardiac echocardiography (ICE) can eliminate the need for GA, expedite procedural logistics, and reduce the patient experience to a simple venous puncture. OBJECTIVE: The purpose of this study was to define optimal ICE views and compare procedural parameters and cost of ICE vs TEE during LAAC with the Watchman device. METHODS: Optimal ICE views of the LAA for Watchman implant were delineated using Carto-Sound and 3-dimensional rendition of the LAA in 6 patients. Procedural and financial parameters of 104 consecutive patients with standard indications for LAAC undergoing Watchman implant using ICE guidance through a single transseptal puncture (n = 53 [51%]) were compared with those of TEE-guided implants (n = 51 [49%]) in 3 centers. RESULTS: Clinical characteristics were similar between the 2 groups. Total in-room, turnaround, and fluoroscopy times all were shorter using ICE (P <.05) under local anesthesia compared to the TEE group. Implant success was 100% in both groups without peri-device leaks or procedural complications. Follow-up TEE showed no significant peri-device leak in both groups. Total hospital charges for ICE with local anesthesia vs TEE were similar, as were total hospital direct and indirect costs. Professional fees were significantly lower with ICE and local anesthesia than with TEE because the charge of anesthesia staff was avoided. CONCLUSION: ICE-guided Watchman implant is safe, feasible, and comparable in cost to TEE during LAAC with a Watchman device but avoids GA and expedites procedure turnaround.
Assuntos
Apêndice Atrial/cirurgia , Fibrilação Atrial/cirurgia , Procedimentos Cirúrgicos Cardíacos/instrumentação , Ecocardiografia Transesofagiana , Custos de Cuidados de Saúde , Ultrassonografia de Intervenção , Idoso , Idoso de 80 Anos ou mais , Apêndice Atrial/diagnóstico por imagem , Fibrilação Atrial/diagnóstico por imagem , Cateterismo Cardíaco , Procedimentos Cirúrgicos Cardíacos/economia , Feminino , Humanos , Masculino , Pessoa de Meia-Idade , Estudos Retrospectivos , Resultado do TratamentoRESUMO
The indications for catheter-based structural and electrophysiological procedures have recently expanded to more complex scenarios, in which an accurate definition of the variable individual cardiac anatomy is key to obtain optimal results. Intracardiac echocardiography (ICE) is a unique imaging modality able to provide high-resolution real-time visualization of cardiac structures, continuous monitoring of catheter location within the heart, and early recognition of procedural complications, such as pericardial effusion or thrombus formation. Additional benefits are excellent patient tolerance, reduction of fluoroscopy time, and lack of need for general anesthesia or a second operator. For these reasons, ICE has largely replaced transesophageal echocardiography as ideal imaging modality for guiding certain procedures, such as atrial septal defect closure and catheter ablation of cardiac arrhythmias, and has an emerging role in others, including mitral valvuloplasty, transcatheter aortic valve replacement, and left atrial appendage closure. In electrophysiology procedures, ICE allows integration of real-time images with electroanatomic maps; it has a role in assessment of arrhythmogenic substrate, and it is particularly useful for mapping structures that are not visualized by fluoroscopy, such as the interatrial or interventricular septum, papillary muscles, and intracavitary muscular ridges. Most recently, a three-dimensional (3D) volumetric ICE system has also been developed, with potential for greater anatomic information and a promising role in structural interventions. In this state-of-the-art review, we provide guidance on how to conduct a comprehensive ICE survey and summarize the main applications of ICE in a variety of structural and electrophysiology procedures.
Assuntos
Técnicas Eletrofisiológicas Cardíacas , Arritmias Cardíacas/diagnóstico por imagem , Arritmias Cardíacas/cirurgia , Fibrilação Atrial/diagnóstico por imagem , Fibrilação Atrial/cirurgia , Átrios do Coração/anatomia & histologia , Átrios do Coração/diagnóstico por imagem , Comunicação Interatrial/diagnóstico por imagem , Comunicação Interatrial/cirurgia , Humanos , Substituição da Valva Aórtica Transcateter , Ultrassonografia de IntervençãoRESUMO
BACKGROUND: Chagasic cardiomyopathy (CC) is the most frequent nonischemic substrate causing left ventricular (LV) tachycardia in Latin America. Systematic characterization of the LV epicardial/endocardial scar distribution and density in CC has not been performed. Additionally, the usefulness of unipolar endocardial electroanatomic mapping to identify epicardial scar has not been assessed in this setting. METHODS AND RESULTS: Nineteen patients with CC undergoing detailed epicardial and endocardial LV tachycardia mapping and ablation were included. A total of 8494 epicardial and 6331 endocardial voltage signals and 314 epicardial/endocardial matched pairs of points were analyzed. Basal lateral LV scar involvement was observed in 18 of 19 patients. Bipolar voltage mapping demonstrated larger epicardial than endocardial scar and core-dense (≤0.5 mV) scar areas (28 [20-36] versus 19 [15-26] and 21 [2-49] versus 4 [0-7] cm2; P=0.049 and P=0.004, respectively). Bipolar epicardial and endocardial voltages within scar were low (0.4 [0.2-0.55] and 0.54 [0.33-0.87] mV, respectively) and confluent, indicating a dense/transmural scarring process in CC. The endocardial unipolar voltage value (with a newly proposed ≤4-mV cutoff) predicted the presence and extent of epicardial bipolar scar (P<0.001). CONCLUSIONS: CC causes a unique ventricular tachycardia substrate concentrated to the basal lateral LV, with marked epicardial predominance. The scar pattern is particularly dense and transmural as compared with the more erratic/patchy scar patterns seen in other nonischemic cardiomyopathies. Endocardial unipolar voltage mapping serves to characterize epicardial scar in this setting.
Assuntos
Potenciais de Ação , Cardiomiopatia Chagásica/complicações , Cicatriz/etiologia , Endocárdio/fisiopatologia , Mapeamento Epicárdico , Miocárdio/patologia , Pericárdio/fisiopatologia , Taquicardia Ventricular/diagnóstico , Idoso , Ablação por Cateter , Cardiomiopatia Chagásica/diagnóstico , Cicatriz/diagnóstico , Endocárdio/patologia , Feminino , Frequência Cardíaca , Humanos , Masculino , Pessoa de Meia-Idade , Pericárdio/patologia , Valor Preditivo dos Testes , Estudos Prospectivos , Taquicardia Ventricular/etiologia , Taquicardia Ventricular/fisiopatologia , Taquicardia Ventricular/cirurgiaAssuntos
Ablação por Cateter/métodos , Diagnóstico por Imagem/métodos , Técnicas de Diagnóstico Cardiovascular , Sistema de Condução Cardíaco/diagnóstico por imagem , Ventrículos do Coração/diagnóstico por imagem , Taquicardia Ventricular/fisiopatologia , Função Ventricular/fisiologia , Sistema de Condução Cardíaco/fisiopatologia , Ventrículos do Coração/fisiopatologia , Humanos , Taquicardia Ventricular/diagnóstico , Taquicardia Ventricular/terapiaRESUMO
Se comunica la ablación de un flúter auricular con una longitud de ciclo de 260 ms en un paciente de 28 años con isomerismoizquierdo y vena cava inferior izquierda interrumpida. Mediante encarrilamiento, demostramos la participación del istmo suprahepáticotricuspídeoen el circuito de macroreentrada. Realizamos líneas de ablación con radiofrecuencia que detuvieron la arritmia primaria yculminó en ritmo de escape noda.
We report the ablation of an atrial flutter with a 260 ms cycle length in a 28-year-old patient with left isomerism and interrupted leftinferior vena cava. We showed the participation of the suprahepatic tricuspid isthmus in the macro reentry circuit by the entrainmentmaneuver.
Assuntos
Humanos , Masculino , Adulto , Flutter Atrial , Cardiopatias Congênitas/complicações , Isomerismo , Veia Cava Inferior/patologia , Relatos de CasosRESUMO
La tormenta eléctrica postinfarto agudo de miocardio es una entidad amenazante de la vida y puede estar desencadenada por la isquemia activa secundaria a enfermedad no revascularizada. Adicionalmente la injuria miocárdica y sobre el sistema de conducción puede desencadenar la aparición de extrasístoles ventriculares, las cuales pueden participar como desencadenantes de arritmias ventriculares complejas. La adecuada identificación de las extrasístoles y otros posibles desencadenantes de la taquicardia ventricular son importantes para establecer las acciones terapéuticas que lleven a un adecuado control de la tormenta. Se presenta un caso de un paciente con tormenta arrítmica desencadenada por extrasístole ventricular frecuente con acoplamiento corto, la cual presentaba fenómeno de R en T, y era refractaria a manejo farmacológico, por lo que fue tratada exitosamente con ablación con catéter de radiofrecuencia.
The electric storm after acute myocardial infarction is a life-threatening entity which can be triggered by ischemia secondary to active coronary artery disease; however, myocardial and conduction system injury may trigger the onset of ventricular premature beats, which can be involved as triggers of complex ventricular arrhythmias. The proper identification of these, and other potential triggers of ventricular tachycardia, it is important to establish the correct treatment leading to proper control of the storm. A case of a patient with arrhythmic storm triggered by frequent ventricular extrasystoles with short coupling is presented. It showed R on T phenomenon, and was refractory to pharmacological management, which was successfully treated with radiofrequency catheter ablation.
Assuntos
Humanos , Masculino , Pessoa de Meia-Idade , Ablação por Cateter , Infarto do Miocárdio , Trombose , Taquicardia Ventricular , Ventrículos do CoraçãoRESUMO
Chagas disease, a chronic parasitosis caused by the protozoa Trypanosoma cruzi, is an increasing worldwide problem because of the number of cases in endemic areas and the migration of infected individuals to more developed regions. Chagas disease affects the heart through cardiac parasympathetic neuronal depopulation, immune-mediated myocardial injury, parasite persistence in cardiac tissue with secondary antigenic stimulation, and coronary microvascular abnormalities causing myocardial ischemia. A lack of knowledge exists for risk stratification, management, and prevention of ventricular arrhythmias in patients with chagasic cardiomyopathy. Catheter ablation can be effective for the management of recurrent ventricular tachycardia.
Assuntos
Arritmias Cardíacas , Cardiomiopatia Chagásica , HumanosRESUMO
Objetivo: evaluar a profundidad el efecto de la estimulación ventricular desde el tracto de salida del ventrículo derecho y el ápex, sobre la sincronía ventricular mecánica. Materiales y métodos: estudio analítico de cohorte, en el que se realizó ecocardiograma transtorácico pre y post implante de marcapaso a 20 pacientes (diez por cada grupo) con indicación de marcapaso definitivo, con implante del electrodo en el tracto de salida del ventrículo derecho y el ápex, sin cardiopatía estructural, fracción de eyección > 50 porciento; QRS y conducción aurículo-ventricular normal, con el fin de evaluar la asincronía ventricular mecánica (modo M y Doppler tisular) y los parámetros de implante y programación del dispositivo.Análisis estadístico: los resultados se presentan como promedios, desviación estándar o porcentajes. Las variables continuas se compararon utilizando prueba Chi cuadrado y ANOVA. Se consideró como estadísticamente significativa una p < 0,05.Resultados: en cinco pacientes (25 porciento), se encontró asincronía ventricular pre implante, en siete (70 porciento) asincronía ventricular post implante en el tracto de salida del ventrículo derecho y en cinco (50 porciento) en el ápex. El promedio del retraso interventricular post implante fue de 21,6 ms en el tracto de salida del ventrículo derecho y de 11,5 ms en el ápex (p=0,8). El promedio de retraso septum a pared lateral fue de 73 ms en el tracto de salida del ventrículo derecho y de 26 ms en el ápex (p=0,8). El del QRS post implante fue de 134 ms en el tracto de salida del ventrículo derecho y de 140 ms en el ápex (p=0,1). No hubo diferencias en parámetros de implante y programación del dispositivo. Conclusiones: se evidenció presencia de asincronía ventricular en pacientes con QRS normal y corazón con estructura sana. La estimulación ventricular con marcapaso desde el ápex o el tracto de salida del ventrículo derecho, sugiere asincronía ventricular aguda al menos en 60 porciento de los casos, sin diferencia estadísticamente significativa entre ambos grupos.
Assuntos
Estimulação Cardíaca Artificial , Vasos Coronários , Diagnóstico , Ecocardiografia , Marca-Passo ArtificialRESUMO
BACKGROUND: The purpose of this study is to determine whether initial vector force might best distinguish tachycardias arising from the right ventricular (RV) outflow tract (OT) versus aortic sinus cusps (ASCs). METHODS: Among 45 patients with OT tachycardia, we measured the time from the earliest QRS onset in any lead to local onset and to the first QRS peak/nadir in each surface leads during VT. We compared the earliest phase differences among patients with foci in RVOT (n = 32) and in ASCs (n = 13) (determined by ablation), using unpaired t-tests. We determined the optimum cut-points by analyzing the receiver-operator characteristics curves, and derived an algorithm to discriminate ASC from RVOT foci. RESULTS: Compared with an RVOT focus, origin in the ASC was associated with lower likelihood that the earliest lead of QRS activation was V2 (4/13 [12%] vs 29/32 [88%], P = 0.0001), later initial peak/nadir in III (110 +/- 19 vs 93 +/- 16 ms, P = 0.0026) and V2 (75 +/- 26 vs 42 +/- 19 ms, P < 0.0001). After determining the optimum cut-points for each, we found that the presence of any one of these findings discriminated well between RVOT and ASC foci (sensitivity 92%, specificity 88%, positive predictive value 75%, and negative predictive value 97%). The sensitivity and specificity using standard ECG criteria were inferior to the vector approach. CONCLUSIONS: The ECG phase differences during VT can distinguish the origin of OT-VT. Earliest onset or first peak/nadir in V2 and early initial peak/nadir in the inferior leads suggest a RVOT focus.