A Case of Acute-Onset Heart Failure Derived from Infective Endocarditis Coinciding With H1N1 Influenza Myocarditis

Abstract

congestion derived from worse mitral valve regurgitation (MR) together with complete left bundle branch block (LBBB) and left ventricular (LV) dyssynchrony. As HF was relieved swiftly using pharmacological intervention and oxygen supplementation, MR was diminished and LBBB recovered to narrow QRS intraventricular conduction.Since cardiac resynchronization therapy (CRT) was introduced in July-2009, her clinical status has been stable without any cardiac events including HF hospitalization,and moreover, the enlarged and impaired LV has gradually reversed together with reduced MR. Although intermittent LBBB is caused by changes in the heart rate, autonomic nervous tone or myocardial ischemia,, there have been few reports concerning deteriorated HF of contributing the appearance of LBBB except in some cases of acute pulmonary embolism. LV dyssynchrony by sudden onset of LBBB could induce not only decrease contraction of LV but also increased MR through interfering with the proper closure of the mitral valve, leading to exacerbation of HF. CRT is a reliable, therapeutic option in cases with intermittent LBBB coincident with acutely-decompensated HF.