Key result
Intermediate QRS prolongation after anterior myocardial infarction was associated with larger left ventricular end-diastolic volume (137.4 vs 87.9 ml, p=0.004) and lower ejection fraction.
Why the study?
Does intermediate QRS prolongation correlate with worse left ventricular volume and ejection fraction in patients with prior anterior myocardial infarction?
Observational (n=82)
Does intermediate QRS prolongation correlate with worse left ventricular volume and ejection fraction in patients with prior anterior myocardial infarction?
Absolute Event Rate: 137.4% vs 87.9%
p-value: p=.004
Intermediate QRS prolongation (≥100 ms without bundle branch block) is independently associated with larger left ventricular volumes and lower ejection fraction after anterior myocardial infarction.
Intermediate QRS prolongation may reflect adverse LV remodeling after anterior MI; leaves open independent prognostic value beyond imaging.
BACKGROUND: Even intermediate QRS prolongation without bundle branch block is associated with worse clinical outcome after myocardial infarction (MI). We assessed the association of QRS duration with left ventricular (LV) volume and ejection fraction after anterior MI by using quantitative gated single photon emission computed tomography (SPECT). METHODS: Eighty-two patients with prior anterior MI were enrolled. Intermediate QRS prolongation was defined as QRS duration ≥100 ms without bundle branch block. Quantitative analysis of thallium SPECT was performed on the redistribution image. LV end-diastolic volume (LVEDV), end-systolic volume (LVESV) and ejection fraction (LVEF) were obtained. RESULTS: There were 25 patients with intermediate QRS prolongation and 57 patients with normal QRS duation. Compared to patients with normal QRS duration, patients with intermediate QRS prolongation had larger LVEDV (137.4 ± 75.1 ml vs 87.9 ± 43.6 ml, p = .004), larger LVESV (89.9 ± 69.6 ml vs 49.2 ± 35.5 ml, p = .009) and lower LVEF (39.3 ± 14.6% vs 47.6 ± 12.0%, p = .02). QRS duration was positively associated with LVEDV (r = 0.49, p < .001) and LVESV (r = 0.47, p < .001), and was inversely associated with LVEF (r= -0.32, p < .001). Multivariate analysis showed that male sex (β = 0.22, p = .04), QRS duration (β = 0.34, p = .002) and number of abnormal Q waves (β = 0.37, p < .001) were associated with LVEDV. QRS duration (β= -0.32, p = .003) and number of abnormal Q waves (β = -0.40, p < .001) were associated with LVEF. CONCLUSIONS: Our results suggest that QRS duration as well as number of abnormal Q waves is independently associated with LV volume and ejection fraction after anterior MI.
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Kurisu et al. (2017) conducted an observational in anterior myocardial infarction (n=82). Intermediate QRS prolongation (≥100 ms without bundle branch block) vs. Normal QRS duration was evaluated on Left ventricular end-diastolic volume (LVEDV) (p=.004). Intermediate QRS prolongation after anterior myocardial infarction was associated with larger left ventricular end-diastolic volume (137.4 vs 87.9 ml, p=0.004) and lower ejection fraction.
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