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Circumferential myocardial strain in cardiomyopathy with and without left bundle branch block.

Han Y, Chan J, Haber I, Peters DC, Zimetbaum PJ, Manning WJ, Yeon SB - J Cardiovasc Magn Reson (2010)

Bottom Line: Patterns of circumferential strain were analyzed.Time to peak systolic circumferential strain in each of the 6 segments in all three ventricular slices and the standard deviation of time to peak strain in the basal and mid ventricular slices were determined.Peak circumferential strain shortening was significantly reduced in all cardiomyopathy patients at the mid-ventricular level (LBBB 9 +/- 6%, non-LBBB 10 +/- 4% vs. healthy 19 +/- 4%; both p < 0.0001 compared to healthy), but was similar among the LBBB and non-LBBB groups (p = 0.20).

View Article: PubMed Central - HTML - PubMed

Affiliation: Departments of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. yhan@bidmc.harvard.edu

ABSTRACT

Background: Cardiac resynchronization therapy (CRT) has been shown to decrease mortality in 60-70% of advanced heart failure patients with left bundle branch block (LBBB) and QRS duration > 120 ms. There have been intense efforts to find reproducible non-invasive parameters to predict CRT response. We hypothesized that different left ventricular contraction patterns may exist in LBBB patients with depressed systolic function and applied tagged cardiovascular magnetic resonance (CMR) to assess circumferential strain in this population.

Methods: We determined myocardial circumferential strain at the basal, mid, and apical ventricular level in 35 subjects (10 with ischemic cardiomyopathy, 15 with non-ischemic cardiomyopathy, and 10 healthy controls). Patterns of circumferential strain were analyzed. Time to peak systolic circumferential strain in each of the 6 segments in all three ventricular slices and the standard deviation of time to peak strain in the basal and mid ventricular slices were determined.

Results: Dyskinesis of the anterior septum and the inferior septum in at least two ventricular levels was seen in 50% (5 out of 10) of LBBB patients while 30% had isolated dyskinesis of the anteroseptum, and 20% had no dyskinesis in any segments, similar to all of the non-LBBB patients and healthy controls. Peak circumferential strain shortening was significantly reduced in all cardiomyopathy patients at the mid-ventricular level (LBBB 9 +/- 6%, non-LBBB 10 +/- 4% vs. healthy 19 +/- 4%; both p < 0.0001 compared to healthy), but was similar among the LBBB and non-LBBB groups (p = 0.20). The LBBB group had significantly greater dyssynchrony compared to the non-LBBB group and healthy controls assessed by opposing wall delays and 12-segment standard deviation (LBBB 164 +/- 30 ms vs. non-LBBB 70 +/- 17 ms (p < 0.0001), non-LBBB vs. healthy 65 +/- 17 ms (p = 0.47)).

Conclusions: Septal dyskinesis exists in some patients with LBBB. Myocardial circumferential strain analysis enables detailed characterization of contraction patterns, strengths, and timing in cardiomyopathy patients with and without LBBB.

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All three types of septal contraction pattern can be observed in both ischemic (ICM) and non-ischemic (non-ICM) cardiomyopathy patients. In LBBB Type Ia, only the anteroseptum is dyskinetic. In LBBB Type Ib, both anteroseptum and inferoseptum are dyskinetic. In LBBB Type II, neither anteroseptum nor inferoseptum is dyskinetic. AS = anteroseptum, IS = inferoseptum.
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Figure 4: All three types of septal contraction pattern can be observed in both ischemic (ICM) and non-ischemic (non-ICM) cardiomyopathy patients. In LBBB Type Ia, only the anteroseptum is dyskinetic. In LBBB Type Ib, both anteroseptum and inferoseptum are dyskinetic. In LBBB Type II, neither anteroseptum nor inferoseptum is dyskinetic. AS = anteroseptum, IS = inferoseptum.

Mentions: We found no difference in time to peak εcc in ischemic and non-ischemic patients stratified by LBBB and non-LBBB. In three out of four patients with evidence for > 75% scar in the infarcted walls, there was no circumferential contraction (εcc ≈ 0). These three segments were excluded from timing analysis due to the absence of peak circumferential shortening. All remaining infarct segments were included in the analysis. One patient with ICM and non-LBBB had > 75% scar in the anteroseptum, but the εcc in that segment was not near 0. In Figure 4, we show side by side the εcc in the anteroseptum and inferoseptum of ICM and non-ICM patients with Type Ia, Type Ib, and Type II LBBB patterns.


Circumferential myocardial strain in cardiomyopathy with and without left bundle branch block.

Han Y, Chan J, Haber I, Peters DC, Zimetbaum PJ, Manning WJ, Yeon SB - J Cardiovasc Magn Reson (2010)

All three types of septal contraction pattern can be observed in both ischemic (ICM) and non-ischemic (non-ICM) cardiomyopathy patients. In LBBB Type Ia, only the anteroseptum is dyskinetic. In LBBB Type Ib, both anteroseptum and inferoseptum are dyskinetic. In LBBB Type II, neither anteroseptum nor inferoseptum is dyskinetic. AS = anteroseptum, IS = inferoseptum.
© Copyright Policy - open-access
Related In: Results  -  Collection

License
Show All Figures
getmorefigures.php?uid=PMC2806866&req=5

Figure 4: All three types of septal contraction pattern can be observed in both ischemic (ICM) and non-ischemic (non-ICM) cardiomyopathy patients. In LBBB Type Ia, only the anteroseptum is dyskinetic. In LBBB Type Ib, both anteroseptum and inferoseptum are dyskinetic. In LBBB Type II, neither anteroseptum nor inferoseptum is dyskinetic. AS = anteroseptum, IS = inferoseptum.
Mentions: We found no difference in time to peak εcc in ischemic and non-ischemic patients stratified by LBBB and non-LBBB. In three out of four patients with evidence for > 75% scar in the infarcted walls, there was no circumferential contraction (εcc ≈ 0). These three segments were excluded from timing analysis due to the absence of peak circumferential shortening. All remaining infarct segments were included in the analysis. One patient with ICM and non-LBBB had > 75% scar in the anteroseptum, but the εcc in that segment was not near 0. In Figure 4, we show side by side the εcc in the anteroseptum and inferoseptum of ICM and non-ICM patients with Type Ia, Type Ib, and Type II LBBB patterns.

Bottom Line: Patterns of circumferential strain were analyzed.Time to peak systolic circumferential strain in each of the 6 segments in all three ventricular slices and the standard deviation of time to peak strain in the basal and mid ventricular slices were determined.Peak circumferential strain shortening was significantly reduced in all cardiomyopathy patients at the mid-ventricular level (LBBB 9 +/- 6%, non-LBBB 10 +/- 4% vs. healthy 19 +/- 4%; both p < 0.0001 compared to healthy), but was similar among the LBBB and non-LBBB groups (p = 0.20).

View Article: PubMed Central - HTML - PubMed

Affiliation: Departments of Medicine (Cardiovascular Division), Beth Israel Deaconess Medical Center, Harvard Medical School, Boston, MA, USA. yhan@bidmc.harvard.edu

ABSTRACT

Background: Cardiac resynchronization therapy (CRT) has been shown to decrease mortality in 60-70% of advanced heart failure patients with left bundle branch block (LBBB) and QRS duration > 120 ms. There have been intense efforts to find reproducible non-invasive parameters to predict CRT response. We hypothesized that different left ventricular contraction patterns may exist in LBBB patients with depressed systolic function and applied tagged cardiovascular magnetic resonance (CMR) to assess circumferential strain in this population.

Methods: We determined myocardial circumferential strain at the basal, mid, and apical ventricular level in 35 subjects (10 with ischemic cardiomyopathy, 15 with non-ischemic cardiomyopathy, and 10 healthy controls). Patterns of circumferential strain were analyzed. Time to peak systolic circumferential strain in each of the 6 segments in all three ventricular slices and the standard deviation of time to peak strain in the basal and mid ventricular slices were determined.

Results: Dyskinesis of the anterior septum and the inferior septum in at least two ventricular levels was seen in 50% (5 out of 10) of LBBB patients while 30% had isolated dyskinesis of the anteroseptum, and 20% had no dyskinesis in any segments, similar to all of the non-LBBB patients and healthy controls. Peak circumferential strain shortening was significantly reduced in all cardiomyopathy patients at the mid-ventricular level (LBBB 9 +/- 6%, non-LBBB 10 +/- 4% vs. healthy 19 +/- 4%; both p < 0.0001 compared to healthy), but was similar among the LBBB and non-LBBB groups (p = 0.20). The LBBB group had significantly greater dyssynchrony compared to the non-LBBB group and healthy controls assessed by opposing wall delays and 12-segment standard deviation (LBBB 164 +/- 30 ms vs. non-LBBB 70 +/- 17 ms (p < 0.0001), non-LBBB vs. healthy 65 +/- 17 ms (p = 0.47)).

Conclusions: Septal dyskinesis exists in some patients with LBBB. Myocardial circumferential strain analysis enables detailed characterization of contraction patterns, strengths, and timing in cardiomyopathy patients with and without LBBB.

Show MeSH
Related in: MedlinePlus