Reduction of left ventricular ejection fraction on isometric hand grip and cold pressor in hypertensive patients with left ventricular hypertrophy

Sustained isometric handgrip (SIHG) and cold pressor (CP) tests are used to assess patients suspected of having coronary artery disease (CAD). The normal response to SIHG and CP is that the blood pressure (BP) increases and left ventricular (LV) ejection fraction (EF) either increases or remains unchanged. Both SIHG and CP tests have been shown to reduce LVEF in patients with CAD. We have assessed the effects of SIHG and CP using radionuclide angiography (RA) in hypertensive patients out of which 10 had left ventricular hypertrophy (LVH group) and 8 had no evidence of LVH (non-LVH group). All patients underwent exercice Thallium-201 (201Tl) imaging in order to rule out CAD. In the LVH group, the mean resting systolic BP (SBP) (210.5 +- 4.7 SE) and diastolic BP (DBP) (119.5 +- 2.3) < mean SBP (237 +- 7.3) and DBP (126 +- 3.1) on SIHG (P<0.0001 and <0.001, respectively). The mean resting EF in LVH group (67 +- 4.3) and the non-LVH group (70 +- 4.3) were similar (P=NS). However, on SIHG and CP the mean EF in LVH group decreased (54 +- 4.6) (P<0.0001) and (62 +- 4.3) (P<0.025) respectively. There were no significant changes in EF on SIHG and CP in the non-LVH group. This finding suggests that while screening patients for CAD using RA, reduction of EF on SIHG and CP may also be due to LVH, resulting in false positive tests for CAD, thus reducing specificity for detection of CAD by these tests