Systolic Wall Stress May Affect the Intramural Coronary Blood Flow Velocity in Myocardial Hypertrophy, Independently on the Left Ventricular Mass

AIM: We sought to evaluate the relationship between left ventricular systolic wall stress (LV-SWS) and coronary artery blood flow velocity in patients with LV hypertrophy (LVH). METHODS AND RESULTS: The study population comprised 38 patients, aged 66.7 +/- 12.7, who were divided into two groups based on the LV-SWS median value. Group A included 19 patients at "low-stress" (92.0 +/- 18.0 mmHg/cm2) and group B other 19 patients at "high-stress" (134.2 +/- 32.3 mmHg/cm2) (P < 0.002). Coronary blood flow velocities were measured both in the left anterior descending (LAD) and in the intramural (IM) arteries. There were no significant between-group differences in the main clinical and echocardiographic parameters. Diastolic velocity in the LAD was also comparable, while it was higher in the IM arterioles of patients from group B than from group A (peak velocity 110.9 +/- 35.2 cm/s vs 92.0 +/- 29.4 cm/s, P < 0.02; mean velocity 78.6 +/- 28.8 vs. 56.0 +/- 20.2 cm/s, P < 0.01, respectively). Overall, moderate, but significative, linear correlation was found between IM peak and mean diastolic velocity and LV-SWS (r = 0.41, P = 0.01, and r = 0.44, P = 0.007, respectively), whereas there was no correlation with wall thickening and LV mass. CONCLUSIONS: Main findings from the present study likely suggest that in patients with mild-to-moderate LVH, high blood flow velocity in the IM arterioles, but not in the LAD, may be related to an increase in LV-SWS, rather independent on the absolute LV mass.