Assessment of distribution and evolution of Mechanical dyssynchrony in a porcine model of myocardial infarction by cardiovascular magnetic resonance

Khaled Z. Abd-Elmoniem, Miguel Santaularia Tomas, Tetsuo Sasano, Sahar Soleimanifard, Evert Jan P. Vonken, Amr Youssef, Harsh Agarwal, Veronica L. Dimaano, Hugh Calkins, Matthias Stuber, Jerry L. Prince, Theodore P. Abraham, M. Roselle Abraham

Research output: Contribution to journalArticlepeer-review

Abstract

Background: We sought to investigate the relationship between infarct and dyssynchrony post- myocardial infarct (MI), in a porcine model. Mechanical dyssynchrony post-MI is associated with left ventricular (LV) remodeling and increased mortality. Methods. Cine, gadolinium-contrast, and tagged cardiovascular magnetic resonance (CMR) were performed pre-MI, 9 2 days (early post-MI), and 33 10 days (late post-MI) post-MI in 6 pigs to characterize cardiac morphology, location and extent of MI, and regional mechanics. LV mechanics were assessed by circumferential strain (eC). Electro-anatomic mapping (EAM) was performed within 24 hrs of CMR and prior to sacrifice. Results: Mean infarct size was 21 4% of LV volume with evidence of post-MI remodeling. Global eC significantly decreased post MI (-27 1.6% vs. -18 2.5% (early) and -17 2.7% (late), p < 0.0001) with no significant change in peri-MI and MI segments between early and late time-points. Time to peak strain (TTP) was significantly longer in MI, compared to normal and peri-MI segments, both early (440 40 ms vs. 329 40 ms and 332 36 ms, respectively; p = 0.0002) and late post-MI (442 63 ms vs. 321 40 ms and 355 61 ms, respectively; p = 0.012). The standard deviation of TTP in 16 segments (SD16) significantly increased post-MI: 28 7 ms to 50 10 ms (early, p = 0.012) to 54 19 ms (late, p = 0.004), with no change between early and late post-MI time-points (p = 0.56). TTP was not related to reduction of segmental contractility. EAM revealed late electrical activation and greatly diminished conduction velocity in the infarct (5.7 2.4 cm/s), when compared to peri-infarct (18.7 10.3 cm/s) and remote myocardium (39 20.5 cm/s). Conclusions: Mechanical dyssynchrony occurs early after MI and is the result of delayed electrical and mechanical activation in the infarct.

Original languageEnglish (US)
Article number1
JournalJournal of Cardiovascular Magnetic Resonance
Volume14
Issue number1
DOIs
StatePublished - 2012

ASJC Scopus subject areas

  • Radiological and Ultrasound Technology
  • Radiology Nuclear Medicine and imaging
  • Cardiology and Cardiovascular Medicine

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