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Strain-time curve analysis by speckle tracking echocardiography in cardiac resynchronization therapy: Insight into the pathophysiology of responders vs. non-responders.

To AC, Benatti RD, Sato K, Grimm RA, Thomas JD, Wilkoff BL, Agler D, Popović ZB - Cardiovasc Ultrasound (2016)

Bottom Line: Global εlong was significantly lower in non-responders at pre CRT (p = 0.02) and only improved in responders (p = 0.04) after CRT.Pre CRT septal εlong -time curves in both groups showed early septal contraction with mid-systolic decrease, while lateral εlong showed early stretch followed by vigorous mid to late contraction.Lower εlong in the non-responders may account for their poor response to CRT.

View Article: PubMed Central - PubMed

Affiliation: Section of Cardiovascular Imaging, Department of Cardiovascular Medicine, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, USA.

ABSTRACT

Background: Patients with non-ischemic heart failure etiology and left bundle branch block (LBBB) show better response to cardiac resynchronization therapy (CRT). While these patients have the most pronounced left ventricular (LV) dyssynchrony, LV dyssynchrony assessment often fails to predict outcome. We hypothesized that patients with favorable outcome from CRT can be identified by a characteristic strain distribution pattern.

Methods: From 313 patients who underwent CRT between 2003 and 2006, we identified 10 patients who were CRT non-responders (no LV end-systolic volume [LVESV] reduction) with non-ischemic cardiomyopathy and LBBB and compared with randomly selected CRT responders (n = 10; LVESV reduction ≥15%). Longitudinal strain (εlong) data were obtained by speckle tracking echocardiography before and after (9 ± 5 months) CRT implantation and standardized segmental εlong-time curves were obtained by averaging individual patients.

Results: In responders, ejection fraction (EF) increased from 25 ± 9 to 40 ± 11% (p = 0.002), while in non-responders, EF was unchanged (20 ± 8 to 21 ± 5%, p = 0.57). Global εlong was significantly lower in non-responders at pre CRT (p = 0.02) and only improved in responders (p = 0.04) after CRT. Pre CRT septal εlong -time curves in both groups showed early septal contraction with mid-systolic decrease, while lateral εlong showed early stretch followed by vigorous mid to late contraction. Restoration of contraction synchrony was observed in both groups, though non-responder remained low amplitude of εlong.

Conclusions: CRT non-responders with LBBB and non-ischemic etiology showed a similar improvement of εlong pattern with responders after CRT implantation, while amplitude of εlong remained unchanged. Lower εlong in the non-responders may account for their poor response to CRT.

No MeSH data available.


Related in: MedlinePlus

Individual (a) and averaged (b) strain-time curve of basal lateral segment in the responders prior to cardiac resynchronization therapy. a Individual segmental strain-time curves, normalized for systolic duration, obtained from basal lateral segment in the responders group prior to start of cardiac resynchronization therapy. Systolic duration is defined as the time from the mitral valve closure to aortic valve closure. b Averaged normalized segmental strain-time curve (with error bars indicating standard error) obtained by averaging the data shown in Panel a. Arrows depict the time points corresponding to mid systole (50 %), end-systole (100 %) and post-systole (125 %). CRT, cardiac resynchronization therapy
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Fig2: Individual (a) and averaged (b) strain-time curve of basal lateral segment in the responders prior to cardiac resynchronization therapy. a Individual segmental strain-time curves, normalized for systolic duration, obtained from basal lateral segment in the responders group prior to start of cardiac resynchronization therapy. Systolic duration is defined as the time from the mitral valve closure to aortic valve closure. b Averaged normalized segmental strain-time curve (with error bars indicating standard error) obtained by averaging the data shown in Panel a. Arrows depict the time points corresponding to mid systole (50 %), end-systole (100 %) and post-systole (125 %). CRT, cardiac resynchronization therapy

Mentions: To better characterize segmental εlong profiles in both patient groups pre and post CRT, individual εlong curves were averaged to obtain a characteristic average εlong profile [8, 9]. Figure 2 shows individual εlong curves of the basal anterolateral segment (A), and corresponding group average εlong curve (B) obtained in CRT responders before pacing. Finally, global εlong was calculated by averaging segmental values.Fig 2


Strain-time curve analysis by speckle tracking echocardiography in cardiac resynchronization therapy: Insight into the pathophysiology of responders vs. non-responders.

To AC, Benatti RD, Sato K, Grimm RA, Thomas JD, Wilkoff BL, Agler D, Popović ZB - Cardiovasc Ultrasound (2016)

Individual (a) and averaged (b) strain-time curve of basal lateral segment in the responders prior to cardiac resynchronization therapy. a Individual segmental strain-time curves, normalized for systolic duration, obtained from basal lateral segment in the responders group prior to start of cardiac resynchronization therapy. Systolic duration is defined as the time from the mitral valve closure to aortic valve closure. b Averaged normalized segmental strain-time curve (with error bars indicating standard error) obtained by averaging the data shown in Panel a. Arrows depict the time points corresponding to mid systole (50 %), end-systole (100 %) and post-systole (125 %). CRT, cardiac resynchronization therapy
© Copyright Policy - OpenAccess
Related In: Results  -  Collection

License 1 - License 2
Show All Figures
getmorefigures.php?uid=PMC4835914&req=5

Fig2: Individual (a) and averaged (b) strain-time curve of basal lateral segment in the responders prior to cardiac resynchronization therapy. a Individual segmental strain-time curves, normalized for systolic duration, obtained from basal lateral segment in the responders group prior to start of cardiac resynchronization therapy. Systolic duration is defined as the time from the mitral valve closure to aortic valve closure. b Averaged normalized segmental strain-time curve (with error bars indicating standard error) obtained by averaging the data shown in Panel a. Arrows depict the time points corresponding to mid systole (50 %), end-systole (100 %) and post-systole (125 %). CRT, cardiac resynchronization therapy
Mentions: To better characterize segmental εlong profiles in both patient groups pre and post CRT, individual εlong curves were averaged to obtain a characteristic average εlong profile [8, 9]. Figure 2 shows individual εlong curves of the basal anterolateral segment (A), and corresponding group average εlong curve (B) obtained in CRT responders before pacing. Finally, global εlong was calculated by averaging segmental values.Fig 2

Bottom Line: Global εlong was significantly lower in non-responders at pre CRT (p = 0.02) and only improved in responders (p = 0.04) after CRT.Pre CRT septal εlong -time curves in both groups showed early septal contraction with mid-systolic decrease, while lateral εlong showed early stretch followed by vigorous mid to late contraction.Lower εlong in the non-responders may account for their poor response to CRT.

View Article: PubMed Central - PubMed

Affiliation: Section of Cardiovascular Imaging, Department of Cardiovascular Medicine, Cleveland Clinic, 9500 Euclid Avenue, Cleveland, OH, USA.

ABSTRACT

Background: Patients with non-ischemic heart failure etiology and left bundle branch block (LBBB) show better response to cardiac resynchronization therapy (CRT). While these patients have the most pronounced left ventricular (LV) dyssynchrony, LV dyssynchrony assessment often fails to predict outcome. We hypothesized that patients with favorable outcome from CRT can be identified by a characteristic strain distribution pattern.

Methods: From 313 patients who underwent CRT between 2003 and 2006, we identified 10 patients who were CRT non-responders (no LV end-systolic volume [LVESV] reduction) with non-ischemic cardiomyopathy and LBBB and compared with randomly selected CRT responders (n = 10; LVESV reduction ≥15%). Longitudinal strain (εlong) data were obtained by speckle tracking echocardiography before and after (9 ± 5 months) CRT implantation and standardized segmental εlong-time curves were obtained by averaging individual patients.

Results: In responders, ejection fraction (EF) increased from 25 ± 9 to 40 ± 11% (p = 0.002), while in non-responders, EF was unchanged (20 ± 8 to 21 ± 5%, p = 0.57). Global εlong was significantly lower in non-responders at pre CRT (p = 0.02) and only improved in responders (p = 0.04) after CRT. Pre CRT septal εlong -time curves in both groups showed early septal contraction with mid-systolic decrease, while lateral εlong showed early stretch followed by vigorous mid to late contraction. Restoration of contraction synchrony was observed in both groups, though non-responder remained low amplitude of εlong.

Conclusions: CRT non-responders with LBBB and non-ischemic etiology showed a similar improvement of εlong pattern with responders after CRT implantation, while amplitude of εlong remained unchanged. Lower εlong in the non-responders may account for their poor response to CRT.

No MeSH data available.


Related in: MedlinePlus