RESUMEN
BACKGROUND: Electrocardiogram is the initial test in the investigation of heart disease. Electrocardiographic changes in hypertrophic cardiomyopathy have no set pattern, and correlates poorly with echocardiographic findings. Cardiac magnetic resonance imaging has been gaining momentum for better assessment of hypertrophy, as well as the detection of myocardial fibrosis. OBJECTIVES: To correlate the electrocardiographic changes with the location of hypertrophy in hypertrophic cardiomyopathy by cardiac magnetic resonance. METHODS: This descriptive cross-sectional study evaluated 68 patients with confirmed diagnosis of hypertrophic cardiomyopathy by cardiac magnetic resonance. The patients' electrocardiogram was compared with the location of the greatest myocardial hypertrophy by cardiac magnetic resonance. Statistical significance level of 5% and 95% confidence interval were adopted. RESULTS: Of 68 patients, 69% had septal hypertrophy, 21% concentric and 10% apical hypertrophies. Concentric hypertrophy showed the greatest myocardial fibrosis mass (p < 0.001) and the greatest R wave size in D1 (p = 0.0280). The amplitudes of R waves in V5 and V6 (p = 0.0391, p = 0.0148) were higher in apical hypertrophy, with statistical significance. Apical hypertrophy was also associated with higher T wave negativity in D1, V5 and V6 (p < 0.001). Strain pattern was found in 100% of the patients with apical hypertrophy (p < 0.001). CONCLUSION: The location of myocardial hypertrophy by cardiac magnetic resonance can be correlated with electrocardiographic changes, especially for apical hypertrophy.
Asunto(s)
Cardiomiopatía Hipertrófica/diagnóstico por imagen , Cardiomiopatía Hipertrófica/fisiopatología , Adulto , Anciano , Anciano de 80 o más Años , Estudios Transversales , Ecocardiografía , Femenino , Humanos , Imagen por Resonancia Magnética , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Adulto JovenRESUMEN
diagnóstico concomitante de bloqueio de ramo esquerdo e bloqueio divisional ântero-superior esquerdo é motivo de controvérsias entre cardiologistas, principalmente quando há desvio do eixo vetorcardiográfico do coração para a esquerda. Em uma breve revisão da literatura, descrevemos a anatomia do feixe de His e sua natureza trifascicular, apresentamos a teoria tetrafascicular de Medrano e relembramos os critérios diagnósticos dessas duas entidades eletrocardiográficas. Concluímos que o bloqueio concomitante pode ser encontrado em casos de bloqueios pós-divisionais bifasciculares com maior acometimento do bloqueio divisional ântero-superior. Por outro lado, o cardiologista precisa ter em mente que existem outras causas de desvio do eixo para a esquerda em vigência de bloqueio de ramo esquerdo, entre elas: bloqueio de ramo esquerdo com infarto inferior, bloqueio de ramo esquerdo com infarto agudo do miocárdio ântero-septal e lateral, e vias acessórias atípicas
The concomitant diagnosis of left bundle branch block and anterosuperior hemi-block is controversial among cardiologists, especially when there is left vectorcardiographic axis deviation. In a brief literature review, we describe His bundle's anatomy and its trifascicular nature, we present Medrano's quadrifascicular theory and revise the diagnostic criteria of these two electrocardiographic entities. We conclude that concomitant block might be found in cases of post-divisional bifascicular blocks with greater involvement of the anterosuperior hemiblock. On the other hand, the cardiologist must keep in mind that there are other causes of left axis deviation in the presence of left bundle branch block, such as: inferior infarction, anterior-septal and lateral infarction, and atypical bypass tracts
Asunto(s)
Humanos , Bloqueo de Rama , Electrocardiografía/métodos , Vectorcardiografía/métodos , Nodo Atrioventricular , Fascículo Atrioventricular/anatomía & histología , Corazón , Ventrículos Cardíacos , Tabique InterventricularRESUMEN
Abstract Background: Electrocardiogram is the initial test in the investigation of heart disease. Electrocardiographic changes in hypertrophic cardiomyopathy have no set pattern, and correlates poorly with echocardiographic findings. Cardiac magnetic resonance imaging has been gaining momentum for better assessment of hypertrophy, as well as the detection of myocardial fibrosis. Objectives: To correlate the electrocardiographic changes with the location of hypertrophy in hypertrophic cardiomyopathy by cardiac magnetic resonance. Methods: This descriptive cross-sectional study evaluated 68 patients with confirmed diagnosis of hypertrophic cardiomyopathy by cardiac magnetic resonance. The patients' electrocardiogram was compared with the location of the greatest myocardial hypertrophy by cardiac magnetic resonance. Statistical significance level of 5% and 95% confidence interval were adopted. Results: Of 68 patients, 69% had septal hypertrophy, 21% concentric and 10% apical hypertrophies. Concentric hypertrophy showed the greatest myocardial fibrosis mass (p < 0.001) and the greatest R wave size in D1 (p = 0.0280). The amplitudes of R waves in V5 and V6 (p = 0.0391, p = 0.0148) were higher in apical hypertrophy, with statistical significance. Apical hypertrophy was also associated with higher T wave negativity in D1, V5 and V6 (p < 0.001). Strain pattern was found in 100% of the patients with apical hypertrophy (p < 0.001). Conclusion: The location of myocardial hypertrophy by cardiac magnetic resonance can be correlated with electrocardiographic changes, especially for apical hypertrophy.
Resumo Fundamentos: O eletrocardiograma é o exame inicial na investigação das cardiopatias. As alterações eletrocardiográficas na cardiomiopatia hipertrófica não possuem padrão definido, tendo baixa correlação com o ecocardiograma. A ressonância magnética cardíaca vem ganhando destaque pela melhor avaliação da hipertrofia, bem como pela detecção de fibrose miocárdica. Objetivos: Correlacionar as alterações eletrocardiográficas com a localização da hipertrofia na cardiomiopatia hipertrófica pela ressonância magnética cardíaca. Métodos: Trata-se de estudo descritivo com delineamento transversal que avaliou 68 pacientes com diagnóstico confirmado de cardiomiopatia hipertrófica pela ressonância magnética cardíaca. Comparou-se o eletrocardiograma dos pacientes com a localização de maior hipertrofia miocárdica pela ressonância magnética. Admitiram-se um nível de significância estatística de 5% e intervalo de confiança de 95%. Resultados: Dos 68 pacientes, 69% possuíam hipertrofia septal, 21% concêntrica e 10% apical. A massa de fibrose miocárdica foi maior na hipertrofia concêntrica (p < 0,001), assim como o tamanho da onda R em D1 (p = 0,0280). A amplitude das ondas R em V5 e V6 (p = 0,0391, p = 0,0148) foi maior na hipertrofia apical, com significância estatística. A hipertrofia apical também se relacionou com maior negatividade da onda T em D1, V5 e V6 (p < 0,001). O padrão strain foi encontrado em 100% dos pacientes com hipertrofia apical (p < 0,001). Conclusão: A localização da hipertrofia miocárdica pela ressonância magnética pode ser correlacionada com alterações eletrocardiográficas, principalmente para hipertrofia apical.