Brief Answer: require complete cardiac evaluation Detailed Answer: LBBB is cardiac conduction abnormality in which activation of the left ventricle is delayed, which causes the left ventricle to contract later than the right ventricle. Patients with LBBB require complete cardiac evaluation, and those with LBBB and syncope or near-syncope may require a pacemaker. In young, healthy people with LBBB, and even in older people with LBBB who may have mild heart disease, the drop-off in cardiac efficiency appears to be pretty trivial, and current evidence indicates that LBBB does not pose a problem in these people. Some patients with LBBB, a markedly prolonged QRS (usually > 150 ms), and systolic heart failure may benefit from a biventricular pacemaker, which allows for better synchrony of heart contractions. thanks

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