Miocarditis aguda primaria. Experiencia de diez años en el Instituto Nacional de Cardiología "Ignacio Chávez" / Primary Acute Myocarditis. A 10- years institutional experience at the National Institute of Cardiology "I. Chavez"

RESUMEN

La miocarditis aguda (MA) se asocia a infecciones virales Coxsackie B, ECHOvirus y otros. Mecanismos autoinmunes se suponen patogénicos. La clínica es variable. El beneficio de inmunosupresión clásica (prednisona-azatioprina) o inmunomodulación (IgG-monomérica) no ha sido confirmado. Objetivo: Revisar la incidencia y enfoque de estudio de la miocarditis. Material y métodos: De 1992-2003, aplicamos un cuestionario estándar a 49 pacientes consecutivos con diagnóstico establecido en forma independiente. Se excluyeron MA con causa identificable. Resultados: La MA ocurrió en 17 mujeres y 32 hombres, edad (mediana) 24 y 28 años. Predominaron disnea/ortopnea (70-47%), edema/plétora yugular (41-37%), dolor precordial y taquicardia (50%). En 22 (45%) la clase funcional era III-IV. El electrocardiograma mostró taquicardia sinusal (35%) y bloqueos de rama (24%). En 47 pacientes el ecocardiograma mostró FEVI 41% (promedio), DDVI 53 mm (promedio) y discinesia 89%. En 11 (22%) casos investigamos anticuerpos contra Coxsackie/ECHOvirus, 6 (54%) tenían anticuerpo reconocido. Veintinueve casos (61%) progresaron a miocardiopatía dilatada (MD), hubo tres defunciones (6%). No fue posible valorar tratamiento inmunomodulador, se estudió sólo a 12 casos. Conclusiones: La incidencia de MAes 1/1,000 ingresos/año. Es necesario estandarizar manejo diagnóstico y tratamiento, pues la progresión a MD y/o muerte en etapa aguda ocurre en 2/3 de los pacientes.

ABSTRACT

Acute myocarditis (AM) is associated with viral infections Coxsackie and ECHOviruses among others. Autoimmunity has been proposed as a pathogenic mechanism. Benefit of classic immunosuppression (prednisone-azathioprine) or immunomodulation (monomeric-human IgG) is still uncertain. Objective: To review incidence and clinical approach to AM at a Cardiology referral center. Material and methods: A 10-yeard period (1992-2003) is reviewed. A standard ques-tionary was applied to 49 consecutive patients referred by clinicians with a diagnosis of AM. Results: AM was found in 17 women and 32 men, median age 24 and 28 years, respectively. They presented heart failure with dyspnea/ortop-nea (70-47%), peripheral edema/jugular vein plethora (41-37%), chest pain, and tachycardia (50%), NYHA functional class was III-IV in 22. The EKG showed sinus tachycardia or conduction defects. Transthoracic echocardiograms in 47 cases showed EF (mean) of 41% with enlarged left ventricle diameter. Antivirus antibodies were present in 54% of those cases studied, Coxsackie or ECHOvirus were identified through a serologic assay. Twenty-nine (61%) of our cases developed dilated cardiomyopathy, three patients died. It is not possible to reach a conclusion regard to immunomodulation therapy, because it was applied to only 12 patients. Conclusions: At the Instituto Nacional de Cardiología "I. Chávez", AM depicts an incidence of 1/1,000 patients a year. It is necessary to standardize the clinical approach for diagnosis and treatment, progression to dilated cardiomyopathy and deadth during acute stage occurs in two-thirds of our patients.