Introduction to indexes for cardiac resynchronization therapy (CRT) indication

摘要

It is widely accepted that cardiac resynchronization therapy (CRT) is effective as a treatment for advanced heart failure. Verifying the presence of dyssynchrony is important for making a decision regarding this therapy.AlthoughECGfindings of complete left bundle branch block and QRS width were originally regarded as being important, they are not sufficient to select CRT candidates: some patients with CRT may not respond to this therapy based on the current criteria. As an approach for addressing this issue, usefulness of echocardiography, especially tissue Doppler imaging, has often been reported to identify the presence of dyssynchrony. However, since these methods are not always reproducible and accurate, and because dyssynchrony is not the only determinant for successful therapy, a CRT indication cannot be made on the basis of a single index. Since various indexes have been designed and reported to solve this issue, it is important to select appropriate indexes and to provide explanations for their selection. Therefore, we, the Subcommittee for the Cardiac Area of the Terminology and Diagnostic Criteria Committee, Japan Society of Ultrasonics in Medicine, have created this ‘‘Introduction to Indexes for Cardiac Resynchronization Therapy (CRT) Indication.’’ The explanations in this introduction are made based on the knowledge and responsibility of the Subcommittee, and the evidence presented for each index, as well as the indexes themselves, have been chosen and explained based on various reports as of 2009.We will be pleased if these indexes are appropriately applied in clinical practice.