Abstract 2210: Incremental Value of Strain Rate Analyses in Assessing Early and Serial Changes in Regional Left Ventricular Function Post-Myocardial Infarction in Streptozotocin-Induced Diabetic Minipigs
To determine the utility of tissue Doppler imaging (TDI) in detecting serial subclinical changes in left ventricular (LV) function post-myocardial infarction (MI) in streptozotocin (STZ)-induced diabetic (DM) minipigs. Thirteen DM and 13 normal pigs were subjected to occlusion of the mid left anterior descending artery and followed-up. Conventional echo and TDI (to assess regional myocardial functions) were performed at baseline, 30 min, 90 min, and 4 weeks after MI. Mortality rate was higher in DM vs controls (30.8% vs 7.7%, P<0.05). At baseline, LV enddiastolic volume (EDV: 24±4.5 vs 20±4.7ml, P=0.033) and mass (69±31 vs 37±10 g, P=0.003) were significantly greater in DM. After MI, LVEF significantly decreased and EDV increased within each group, though these were not signficant between the 2 groups (Fig⇓). At early post-MI (30 and 90 min) and 4 weeks, systolic velocity could neither differenciate between two groups, nor detect the difference between infarct vs non-infarct regions accurately. Similarly, no differences were observed in LV systolic strain between two groups at different time points, except at 4-weeks: DM pigs have lower strain (Infarct area: 15±4.5 vs 9±2.2%, P=0.005; Non-infarct: 23±5.6 vs 17±2.4%, P=0.025). In contrast, strain rates were significantly lower in DM than controls, both in infarct and non-infarct areas and were able to differentiate between the 2 groups at all time points, early and late (Fig⇓). DM is associated with higher degree of LV dysfunction and remodeling post-MI. Strain rate provides incremental value in evaluating early and subtle LV dysfunction in DM.