Absence of Myocardial Dysfunction during Cold Pressor Stress Echocardiography in Patients with Endothelial Dysfunction

Background: Several methods are available for the assessment of coronary endothelial function, but there are no reports to date regarding the usefulness of cold pressor stress echocardiography (CPSE). Objective: To assess regional systolic and diastolic left ventricular function using CPSE in patients with endothelial dysfunction. Methods: We studied 24 patients, of whom 10 were men, aged 27 to 68 years, who had coronary risk factors and a normal exercise MP-SPECT test. They were compared with 10 normal subjects (6 men), aged 21 to 44 years. All patients underwent a CPSE. Results: The cold pressor-MP-SPECT revealed myocardial ischemia in 10 patients (Group I) and was normal in 14 patients (Group II). All normal subjects (Group III) had normal cold pressor-MP-SPECT. The cold pressor test caused a significant increase in systolic BP in the three groups (baseline 117 ± 17 mmHg vs. postcold test 137 ± 16 mmHg, P < 0.05), without changes in heart rate, PR interval, or the corrected QT interval. During the CPSE, no patient developed WMA in 2D echo or changes in regional systolic or diastolic LV function in the pulsed Doppler tissue imaging. Conclusions: In patients with endothelial dysfunction and no known coronary artery disease, the ischemic response to the cold pressor-MP-SPECT is not accompanied by WMA or changes in regional systolic or diastolic LV function during CPSE. Such negative findings indicate that the amount of ischemia that occurs secondarily to endothelial dysfunction does not involve sufficient myocardial mass to cause contractile dysfunction.