Low diastolic wall strain is associated with raised post-exercise E/E' ratio in elderly patients without obvious myocardial ischemia.

BACKGROUND: It has been reported that the diastolic wall strain (DWS) inversely correlates with the myocardial stiffness constant. The ratio of early diastolic transmitral flow velocity to annulus velocity (E/E') correlates with the left ventricular (LV) filling pressure. Increased LV wall stiffness is thought be associated with increased LV filling pressure after exercise. The purpose of this study was to evaluate the correlation between the DWS and post-exercise E/E' in elderly patients without obvious myocardial ischemia.

METHODS: Fifty-eight elderly patients (age = 74 ± 6 years) who underwent treadmill stress echocardiography were studied. All patients had normal LV wall motion at rest, and patients with exercise-induced wall motion abnormality were excluded. The DWS was calculated as follows: DWS = (PWTs - PWTd)/PWTs, where PWTs is the LV posterior wall thickness at end-systole and PWTd is that at end-diastole. As previously reported, DWS ≤ 0.33 was defined as low DWS and E/E' ≥15.0 was defined as a marker of increased LV filling pressure.

RESULTS: Eighteen patients had low DWS. Patients with low DWS had greater post-exercise E/E' (17.9 ± 3.2 vs. 12.8 ± 3.3, p < 0.0001). The DWS was inversely and strongly correlated with post-exercise E/E' (r (2) = 0.534, p < 0.0001). Low DWS predicted the development of raised post-exercise E/E' ≥15.0 with a positive predictive value of 94 % and a negative predictive value of 85 %.

CONCLUSION: In elderly patients without obvious myocardial ischemia, the DWS correlates strongly and inversely with post-exercise E/E'. Patients with low DWS were likely to develop raised E/E' after exercise.