Predictability of the Left Ventricular Systolic and Diastolic Function according to the QRS Duration for Left Bundle Branch Block Patients

ABSTRACT

BACKGROUND AND OBJECTIVES: Left bundle branch block (LBBB) is an ECG finding that suggests a poor prognosis for patients suffering with cardiovascular disease. The aim of this study was to elucidate the relation between the QRS duration and the left ventricular function in the patients with LBBB. SUBJECTS AND METHODS: 95 patients (M : F=35 : 60, mean age: 69+/-13 yrs) with LBBB observed on ECG were recruited for this study. The relations among the QRS duration, the demographic.clinical findings and the conventional echocardiographic findings, including the LV systolic and diastolic function, were analyzed for these subjects. RESULTS: The QRS duration was closely related to the LV ejection fraction (r=-0.613, p or =158 msec showed a sensitivity of 73% and a specificity of 77% for predicting a LV EF <35%. CONCLUSION: The QRS duration is an important predictor that reflects the disease progression in patients with LBBB. Therefore, the QRS duration should be closely monitored in symptomatic patients with LBBB.