Abstract 6136: ECG Strain Pattern is Related to Endo/Epimyocardial Radial Strain Ratio aCoronary Flow Velocity Reserve in Hypertensive Patients
Background: Hypertensive patients with ECG strain pattern have been reported to have lower survival rate in comparison with those without strain pattern. It remains unclear whether endo/epimyocardial radial strain ratio and coronary flow velocity reserve (CFVR) alter in hypertensive patients, especially in those with ECG strain pattern. We hypothesized that the presence of ECG strain pattern might be related to the changes of endo/epimyocardial radial strain ratio and CFVR in hypertensive patients.
Methods: We enrolled 36 patients with hypertension (mean age; 63+/−17 years old, 21 males) and excluded 5 patients with coronary artery disease, which were revealed by multi-sliced computed tomography and 2 patients with left bundle branch block. The remaining 29 patients were examined and divided into 2 groups, with (group S, n=14) or without (group NS, n=15) ECG strain pattern. Analysis of strain echocardiography was performed using images of the short-axis view at papillary muscle level. We divided images into 6 segments and determined endo/epimyoicardial radial strain ratio in each segment and averaged using 2D tracking software (Toshiba Medical Systems, Japan). CFVR was assessed by trans-thoracic Doppler echocardiography and calculated as the ratio of hyperemic, which was induced by intravenous adenosine tri-phosphate administration, to baseline coronary flow velocity of the left anterior descending coronary artery using Vivid 7 Dimension (GE Medical systems, Milwaukee, WI).
Results: Strain analysis and CFVR measurements were successfully performed in all the patients, Endo/epimyocardial radial strain ratio in group NS were greater than those in group S (1.6+/−0.6 vs. 1.1+/−0.3, p=0.03, respectively). CFVR in group S were also reduced in comparison with those in group NS (2.1+/−0.6 vs. 2.7+/−0.8, p=0.02, respectively). There was a significant correlation between endo/epimyocardial radial strain ratio and CFVR (r=0.45, p=0.02).
Conclusion: In hypertensive patients with ECG strain pattern, both endo/epimyocardial strain ratio and CFVR were reduced These findings might contribute to clarify the mechanisms of deterioration in cardiac function among hypertensive patients with ECG strain pattern.