RESUMO
BACKGROUND: Right bundle branch block (RBBB) evident in the precordial ECG leads may be associated with evidence of left bundle branch involvement in the limb leads. Any of the components of the left bundle can be involved, and this complex interventricular conduction abnormality has previously been described in patients with underlying heart disease. OBJECTIVES: To analyze the electro-vectorcardiographic manifestations of RBBB with left middle septal fiber block (LMSFB), with or without left anterior fascicular block (LAFB) in premature atrial beats of patients without apparent structural heart disease. METHODS: Twelve patients (8 men/4 women; mean age: 32±8years) with premature atrial contractions with this conduction abnormality were included. Surface 12 simultaneous lead ECG recordings and the corresponding vectorcardiographic loops were analyzed. RESULTS: The QRS complexes with RBBB and also LMSFB persisted for between 150 and 190ms. There were no q waves in lead I. The maximum spatial vector (72-86ms) was directed posteriorly, superiorly, and leftward, and the terminal forces were oriented anteriorly, inferiorly and rightward. In 10 patients, small q waves were apparent in leads V1-V2 and the frontal QRS axis was -60° and -70°, with the 46ms vector located at -50°±5. All of these patients most probably had LAFB in addition to LMSFB. In two patients, the initial electrical forces were directed anteriorly, inferiorly, and leftward, and the 46ms vector axis in the frontal plane was 6° and 11°, respectively, indicating absence of LAFB. CONCLUSIONS: The combination of RBBB and LMSFB occurring in patients without apparent structural heart disease may be related to the simultaneous occurrence of block of conduction through these components of the Purkinje network. The anterior fascicle of the left bundle may also be involved.
Assuntos
Fascículo Atrioventricular/fisiopatologia , Bloqueio de Ramo/diagnóstico , Bloqueio de Ramo/fisiopatologia , Sistema de Condução Cardíaco/fisiopatologia , Septos Cardíacos/fisiopatologia , Vetorcardiografia/métodos , Adulto , Bloqueio de Ramo/classificação , Diagnóstico Diferencial , Reações Falso-Negativas , Feminino , Humanos , Masculino , Valores de Referência , Reprodutibilidade dos Testes , Sensibilidade e EspecificidadeRESUMO
INTRODUCTION AND OBJECTIVES: Doppler tissue imaging (DTI) enables regional myocardial function to be assessed irrespective of preload. Our aim was to determine the usefulness of DTI in healthy relatives of patients with familial hypertrophic cardiomyopathy. PATIENTS AND METHOD: We studied 47 first-degree relatives of patients with familial hypertrophic cardiomyopathy (group GI) and 47 normal subjects (group GII). Echocardiographic studies, including DTI, were performed in both groups. DTI was used to measure myocardial velocities during systole (S'), early diastole (E') and atrial contraction (A') at the mitral annulus, septum, and tricuspid annulus. Isovolumic relaxation and contraction times were corrected for heart rate. With DTI assessment of regional diastolic myocardial function and use of the E'/A' ratio, normal (i.e., E'/A'>1) and abnormal (i.e., E'/A'<1) diastolic function could be distinguished. RESULTS: There were no abnormalities in regional diastolic function in group GII (right E'/A' 1.78 (0.58), septum E'/A' 2.03 (0.53), and left E'/A' 2.55 (0.80). However, in group GI, two subgroup could be distinguished using E'/A' ratio values: group GIa comprised 37 first-degree relatives with normal diastolic function (right E'/A' 1.8 (0.44), septum E'/A' 2.07 (0.41), and left E/A 2.35 (0.6) who did not differ significantly from control subjects, and group GIb comprised 10 first-degree relatives with abnormal right diastolic function (right E'/A' 0.70 (0.28), P<.001) but with less significant differences at the septum (1.57 (0.49), P<.01) and mitral annulus (1.85 (0.53), P<.01). CONCLUSIONS: In 10 of 47 (21.3%) first-degree relatives of patients with familial hypertrophic cardiomyopathy, DTI enabled the detection of ventricular diastolic abnormalities, which were more evident in the right ventricle. They could be a preclinical manifestation of disease.
Assuntos
Cardiomiopatia Hipertrófica Familiar/genética , Diástole , Ecocardiografia Doppler de Pulso , Ventrículos do Coração/diagnóstico por imagem , Adolescente , Adulto , Criança , Diagnóstico Precoce , Feminino , Ventrículos do Coração/fisiopatologia , Humanos , MasculinoRESUMO
We present a 56-year-old man who was admitted to an emergency service after receiving an electric shock. The ECG showed a J point and ST segment elevation of up to 5 mm in leads V1 to V3, which normalized in 24 hours. The ajmaline test caused elevation of the J point and of the ST segment up to 12 mm in leads V1 to V3, QTc lengthening, and QTc and T wave alternans. These results denoted alterations in the duration of myocardial action potentials, a common finding in patients with Brugada syndrome and long QT syndrome.
Assuntos
Eletrocardiografia , Síndrome do QT Longo/diagnóstico , Ajmalina , Antiarrítmicos/uso terapêutico , Traumatismos por Eletricidade/complicações , Humanos , Síndrome do QT Longo/tratamento farmacológico , Síndrome do QT Longo/etiologia , Masculino , Pessoa de Meia-Idade , SíndromeRESUMO
Se seleccionaron en forma retrospectiva 12 registros de muerte súbita ambulatoria. Se analizaron las arritmias causantes de la muerte súbita, las alteraciones del ritmo y del electrocardioograma que la precedieron y las circunstancias en las que ocurrió. En diez pacientes (83,33 por ciento) la muerte súbita se debió a fibrilación ventricular, precedida en 6 por taquicardia ventricular sostenida, en 2 por torsades de pointes y en los otros 2 pacientes la fibrilación ventricular fue la única arritmia. Dos pacientes fallecieron en bradiarritmia (16,66 por ciento), uno en asistolia y el otro en disociación electromecánica. Las taquiarritmias ventriculares son la causa más común de muerte súbita ambulatoria
Assuntos
Humanos , Masculino , Feminino , Pessoa de Meia-Idade , Arritmias Cardíacas/etiologia , Morte Súbita Cardíaca/etiologia , Eletrocardiografia Ambulatorial , Frequência Cardíaca , Taquicardia Ventricular/mortalidadeRESUMO
Se seleccionaron en forma retrospectiva 12 registros de muerte súbita ambulatoria. Se analizaron las arritmias causantes de la muerte súbita, las alteraciones del ritmo y del electrocardioograma que la precedieron y las circunstancias en las que ocurrió. En diez pacientes (83,33 por ciento) la muerte súbita se debió a fibrilación ventricular, precedida en 6 por taquicardia ventricular sostenida, en 2 por torsades de pointes y en los otros 2 pacientes la fibrilación ventricular fue la única arritmia. Dos pacientes fallecieron en bradiarritmia (16,66 por ciento), uno en asistolia y el otro en disociación electromecánica. Las taquiarritmias ventriculares son la causa más común de muerte súbita ambulatoria (AU)