Assessment of Atrial Contribution to Left Ventricular Filling during Cold Pressor Test by M-mode Echocardiography in Patients with Coronary Artery Disease

ABSTRACT. To determine whether temporarily increased afterload causes changes in left ventricular (LV) diastolic properties, we examined 19 patients with coronary artery disease (CAD) and 14 healthy subjects by M-mode echocardiography during immersion of the left hand in ice water. The M-mode echocardiograms were digitized to assess the percentage of atrial contribution (%AC) to LV filling as a marker of diastolic properties. Six patients and 5 controls had to be excluded owing to inability to clearly define the endocardium in the left ventricle throughout the entire heart cycle. In the control situation, the %AC did not differ significantly between the two groups. During the cold pressor test, the mean %AC at peak systolic and peak diastolic pressures was significantly higher in the CAD group than in the control group (p < 0.05). Thus, by using M-mode echocardiography during the cold pressor test it is possible to document an increased atrial contribution to LV filling in patients with CAD. It is suggested that the mechanism is increased myocardial stiffness evoked by ischaemia with a resultant increased role of atrial contraction.