The Echocardiographic Assessment of Dyssynchrony: Insights from a Consecutive Series of General Cardiology Patients with Normal LVEF and Narrow QRS

Abstract

Prior studies have described the potential benefit of using echocardiographic rather than ECG techniques to help select the subgroup of heart failure patients that are most likely to benefit from cardiac resynchronization therapy (CRT). Currently, the most commonly used echocardiographic techniques to assess dyssynchrony include discrepancies in radial motion derived from M-mode and in longitudinal motion derived from tissue Doppler; however, there are little data available on the range of these measurements in the general cardiology population. A consecutive series of patients referred for a stress echocardiogram were screened for normal LV systolic function and normal QRS width. Fifty-one patients met inclusion criteria and underwent dyssynchrony measurements in addition to their baseline echo. Previously proposed cutoff values were applied. We observed 17% of study subjects were above the reported normal values for radial dyssynchrony and 41% were above the reported normal values for longitudinal dyssynchrony. However, when both criteria were required to be abnormal only 4% were classified as dyssynchronous. Echocardiographic indices in general cardiology patients appear most accurate when radial and longitudinal parameters are used in combination. While the ideal cutoff values remain to be determined, this combination may optimize patient selection for CRT response.