Published in:
Open Access
01-12-2017 | Research article
Longitudinal shortening remains the principal component of left ventricular pumping in patients with chronic myocardial infarction even when the absolute atrioventricular plane displacement is decreased
Authors:
Daniel Asgeirsson, Erik Hedström, Jonas Jögi, Ulrika Pahlm, Katarina Steding-Ehrenborg, Henrik Engblom, Håkan Arheden, Marcus Carlsson
Published in:
BMC Cardiovascular Disorders
|
Issue 1/2017
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Abstract
Background
The majority (60%) of left ventricular (LV) stroke volume (SV) is generated by longitudinal shortening causing apical atrioventricular plane displacement (AVPD) in systole. The remaining SV is caused by radial inward motion of the epicardium both in the septal and the lateral wall. We aimed to determine if these longitudinal, septal and lateral contributions to LVSV are changed in patients with chronic myocardial infarction (MI).
Methods
Patients with a chronic (>3 months) ST-elevation MI in the left anterior descending (LAD, n = 20) or right coronary artery (RCA, n = 16) and healthy controls (n = 20) were examined with cardiovascular magnetic resonance (CMR). AVPD was quantified in long axis cine CMR images and LV volumes and dimensions in short axis cine images.
Results
AVPD was decreased both in patients with LAD-MI (11 ± 1 mm, p < 0.001) and RCA-MI (13 ± 1 mm, p < 0.05) compared to controls (15 ± 0 mm). However, the longitudinal contribution to SV was unchanged for both LAD-MI (58 ± 3%, p = 0.08) and RCA-MI (59 ± 3%, p = 0.09) compared to controls (64 ± 2%). The preserved longitudinal contribution despite decreased absolute AVPD was a results of increased epicardial dimensions (p < 0.01 for LAD-MI and p = 0.06 for RCA-MI). In LAD-MI the septal contribution to LVSV was decreased (5 ± 1%) compared to both controls (10 ± 1%, p < 0.01) and patients with RCA-MIs (10 ± 1%, p < 0.01). The lateral contribution was increased in LAD-MI patients (44 ± 3%) compared to both RCA-MI (35 ± 2%, p < 0.05) and controls (29 ± 2%, p < 0.001).
Conclusion
Longitudinal shortening remains the principal component of left ventricular pumping in patients with chronic MI even when the absolute AVPD is decreased.