Longitudinal rotation: an unrecognised motion pattern in patients with dilated cardiomyopathy.

<bold>Background: </bold>Heart failure patients who are candidates for CRT frequently display longitudinal rotation (LR) - a swinging motion of the heart when imaged in a horizontal long-axis plane. <bold>Objectives: </bold>To identify the magnitude and predictors of LR in patients with ischaemic (ICM) and idiopathic dilated (DCM) cardiomyopathy, and to assess predictive value of LR in patients undergoing cardiac resynchronisation therapy (CRT). <bold>Design and Setting: </bold>A retrospective study in a tertiary heart care setting. <bold>Methods: </bold>Echocardiography was performed in 45 ICM and 41 DCM patients who were CRT candidates and 16 control subjects. Global LR, segmental strains and segmental LR were assessed from echocardiograms using speckle tracking. Repeat echocardiography >40 days after the beginning of CRT was performed in 64 patients. <bold>Results: </bold>While DCM patients with QRS duration of both <130 ms and > or =130 ms displayed significant clockwise LR (p<0.001 for both vs 0), ICM patients and control subjects had LR that did not differ from 0. The most significant LR predictor was end-diastolic volume (p<0.001) followed by the absence of ischaemia (p<0.001) and QRS duration (p = 0.05). DCM patients with prominent clockwise LR had lower septal but higher lateral strains than DCM patients with minimal LR, or ICM patients with counterclockwise LR. LR correlated with decrease of end-systolic volume in DCM (r = 0.49, p = 0.004), while no relationship was observed in ICM. <bold>Conclusion: </bold>Clockwise LR is linked to presence of DCM, with the small impact of QRS duration. LR is a moderately strong predictor of end-systolic volume decrease during CRT in DCM. [ABSTRACT FROM AUTHOR]