QRS Duration Alone Misses Cardiac Dyssynchrony in a Substantial Proportion of Patients with Chronic Heart Failure

A substantial proportion of patients have dyssynchrony by TSI, but do not have a prolonged QRS duration. These patients may benefit from cardiac resynchronization therapy but on traditional criteria would be excluded from the therapy. Expanding the criteria for cardiac resynchronization therapy to include echocardiographic parameters may extend the benefit of this technology to a greater population in need.