Abnormal coronary reserve and left ventricular wall motion during cold pressor test in patients with previous left ventricular ballooning syndrome

Abstract
To investigate whether and how cold pressor test (CPT) could affect myocardial perfusion and left ventricular (LV) function in patients with previous LV ballooning syndrome (LVBS). Cold pressor test (3 min hand immersion in ice-water) was performed in 17 women with previous LVBS and in 7 age- and risk factor-matched women with chest pain and normal coronary arteries. At baseline and peak CPT, global and regional LV function, and myocardial perfusion were quantitatively assessed by real-time three-dimensional echocardiography (RT3DE) and myocardial contrast (SonoVue, Bracco) 2D echocardiography (MCE), respectively (Philips iE33 machine, X3-1 and S5-1 probes). Data were analysed off-line (QLab 6.0 software). Peripheral venous catecholamines were assayed by high performance liquid chromatography with electrochemical detection. Cold pressor test induced similar haemodynamic changes and catecholamine increase in controls and LVBS patients. Left ventricular ejection fraction decreased and transient new mid-ventricular and apical motion abnormalities developed in LVBS patients only (quantitative RT3D analysis), without corresponding perfusion defects (MCE). At peak CPT, coronary blood flow and velocity increased (quantitative MCE analysis) in control subjects only. Cold pressor test induced LV wall motion abnormalities unmatched to regional coronary flow reduction in LVBS patients only. The reduced coronary reserve in response to CPT suggests microvascular dysfunction in LVBS patients.