Abstract 16710: Evidence of Ischemic Memory From Strain Rate Analysis of Diastolic Function During/After Percutaneous Coronary Intervention
Introduction The ability to detect ischemia occurring prior to the time of examination (ischemic memory) would be of great clinical value. Studies have shown that abnormal left ventricular (LV) diastolic function may be a sensitive marker of myocardial ischemia.HypothesisWe hypothesized that analysis of diastolic function by strain imaging (SI) could detect abnormalities due to myocardial ischemia for some time after percutaneous coronary intervention (PCI).
Methods We performed echograms on 31 pts having angiography, 18 controls (CON) without obstructive CAD and 13 undergoing single vessel PCI (ISCH), at baseline, during balloon occlusion, and for 15, 30, and 60 minutes afterwards. SI analysis of the ischemic segment using speckle tracking was done in parasternal short axis views. The end systolic strain at the closure of the aortic valve (A) and at the time of one-third of diastole (B) were measured. A strain imaging diastolic index (SIDI) was calculated as A-B/Ax100% to examine diastolic performance.
Results (see Table)Baseline characteristics for CON were similar to ISCH: mean age 61 ±14 years, HR 70 ±12, BP 135/70 ±27/13mmHg, male 69%, DM 38%, HTN 100%. SIDI values for ISCH decreased during balloon occlusion and remained low at 60 minutes after reperfusion. SIDI values in CON did not change significantly from baseline for 60 minutes after the procedure. (A) for ISCH decreased from 30.5 ±4% at baseline to 11.4 ±2% at 15 minutes after balloon occlusion and improved slightly to 15.8 ±2% at 60 minutes after reperfusion. (A) values in CON were unchanged from 22.6 ±8% at baseline to 20.8 ±9% at 60 minutes after procedure.
Conclusions Abnormalities of systolic and diastolic strain (manifested by a decrease in SIDI values) occur in response to the induction of myocardial ischemia by PCI. As compared to the change in systolic strain, the change in SIDI values is of greater magnitude, is persistent at 60 minutes after reperfusion, and may be a useful marker of ischemic myocardial memory.
- © 2011 by American Heart Association, Inc.