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. 2017 Dec 13:18:81-85.
doi: 10.1016/j.ijcha.2017.11.005. eCollection 2018 Mar.

The interaction of QRS duration with cardiac magnetic resonance derived scar and mechanical dyssynchrony in systolic heart failure: Implications for cardiac resynchronization therapy

Tom Jackson  1 , Sana Amraoui  2 , Manav Sohal  1 , Eva Sammut  1 , Jonathan M Behar  1 , Simon Claridge  1 , Jessica Webb  1 , Ben Sienecwicz  1 , Reza Razavi  1 , Christopher Aldo Rinaldi  1   3 , Gerald Carr-White  3
Affiliations

The interaction of QRS duration with cardiac magnetic resonance derived scar and mechanical dyssynchrony in systolic heart failure: Implications for cardiac resynchronization therapy

Tom Jackson et al. Int J Cardiol Heart Vasc. .

Abstract

Background: Trials using echocardiographic mechanical dyssynchrony (MD) parameters in narrow QRS patients have shown a negative response to CRT. We hypothesized MD in these patients may relate to myocardial scar rather than electrical dyssynchrony.

Methods: We determined the prevalence of cardiac magnetic resonance (CMR) derived measures of MD in 130 systolic heart failure patients with both broad (≥ 130 ms - BQRS) and narrow QRS duration (< 130 ms - NQRS). We assessed whether late gadolinium enhancement derived scar might explain the presence of MD amongst narrow QRS patients. Dyssynchrony was calculated on the basis of a systolic dyssynchrony index (SDI).

Results: Fifty-nine patients (45%) had a NQRS and the remaining had QRS ≥ 130 ms (BQRS group). 25% of NQRS patients had MD based on SDI. In all narrow and broad QRS patients with MD there was a significantly lower scar volume than those without MD (7.4 ± 10.5% vs 13.7 ± 13.3% vs. p < 0.01). This was the case in the BQRS group with a significantly lower scar burden in patients with MD (5.0 ± 7.7% vs 15.4 ± 15.6%, p < 0.01). Notably in the NQRS group this difference was absent with an equal scar burden in patients with MD 13.3 ± 13.9% and without MD 12.5 ± 11%, p = 0.92.

Conclusions: 25% of patients with systolic heart failure and a NQRS (< 130 ms) have CMR derived mechanical dyssynchrony. Our findings suggest MD in this group may be secondary to myocardial scar rather than electrical dyssynchrony and therefore not amenable to correction by CRT. This may give insight into non-response and potential harm from CRT in this group.

Keywords: Cardiac magnetic resonance imaging; Cardiac resynchronization therapy; Dyssynchrony; Narrow QRS.

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Figures

Fig. 1
Fig. 1
A) Box plot of CMR-SDI (SDI 16%) for patients with a QRS < 130 ms and QRS ≥ 130 ms. Grey horizontal line represents mean for entire cohort. B) Scatter diagram of QRS duration (ms) and Systolic CMR-SDI (SDI 16%). with regression line of best fit and 95% confidence intervals (dashed lines); R = 0.38, p < 0.01.
Fig. 2
Fig. 2
Scatter diagrams of left ventricular scar volume (%age scar) plotted against CMR-SDI (SDI 16%) in A and QRS duration in B. Patients with no scar are represented with grey datapoints.
Fig. 3
Fig. 3
Box plots of left ventricular scar volume (Scar %) for those patients with and without mechanical dyssynchrony (MD). Plot A is all patients, B is narrow QRS patients (QRS < 130 ms), and C is Broad QRS patients (QRS ≥ 130 ms).
See this image and copyright information in PMC

References

    1. Kashani A., Barold S.S. Significance of QRS complex duration in patients with heart failure. J. Am. Coll. Cardiol. 2005;46(12):2183–2192. - PubMed
    1. Brignole M., Auricchio A., Baron-Esquivias G. 2013 ESC guidelines on cardiac pacing and cardiac resynchronization therapy: the Task Force on cardiac pacing and resynchronization therapy of the European Society of Cardiology (ESC). Developed in collaboration with the European Heart Rhythm Association (EHRA) Eur. Heart J. 2013;34(29):2281–2329. - PubMed
    1. Chung E.S., Leon A.R., Tavazzi L. Results of the predictors of response to CRT (PROSPECT) trial. Circulation. 2008;117(20):2608–2616. - PubMed
    1. Yu C.M., Lin H., Zhang Q., Sanderson J.E. High prevalence of left ventricular systolic and diastolic asynchrony in patients with congestive heart failure and normal QRS duration. Heart. 2003;89(1):54–60. - PMC - PubMed
    1. Bleeker G.B., Schalij M.J., Molhoek S.G. Frequency of left ventricular dyssynchrony in patients with heart failure and a narrow QRS complex. Am. J. Cardiol. 2005;95(1):140–142. - PubMed

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