EFFECTS OF ADENOSINE INFUSION ON SYSTOLIC AND DIASTOLIC LEFT-VENTRICULAR FUNCTION AFTER CORONARY-ARTERY BYPASS-SURGERY - EVALUATION BY COMPUTER-ASSISTED QUANTITATIVE 2-D AND DOPPLER-ECHOCARDIOGRAPHY

The effects of adenosine on central hemodynamics, ST-segment changes, and left ventricular (LV) systolic and diastolic function, determined by transesophageal 2-D and Doppler echocardiography, were investigated in 20 patients shortly after coronary surgery. After control measurem ents, adenosine was infused at incremental infusion rates (30, 60, and 120 mu g.kg(-1).min(-1)). Adenosine caused dose-dependent increases i n heart rate (68.0 +/- 11.2-74.0 +/- 15.7 bpm), cardiac output (3.23 /- 0.76-4.17 +/- 0.67 L/min), and stroke volume (48.8 +/- 12.5-56.7 mL ), decreases in arterial pressure (84.8 +/- 16.6-63.3 +/- 15.2 mm Hg), and systemic and pulmonary vascular resistances (1994 +/- 510-1106 +/ - 309 and 209 +/- 54-116 +/- 58 dyne.s.cm(-5), respectively), but no c hanges in cardiac filling pressures. The mean ST segment was slightly but significantly depressed by adenosine (from 0.003 to 0.019 mV). Ana lysis of LV wall motion showed that adenosine caused no changes in the global area ejection fraction (GAEF), the segmental area ejection fra ction (SAEF), or in the SAEF/GAEF ratio, indicating that no regional w all motion abnormalities appeared. Maximum early and late diastolic fl ow rates (E(max), A(max)), determined by mitral Doppler analysis, incr eased (from 30.1 +/- 14.8 to 40.1 +/- 24.1 and from 37.8 +/- 15.7 to 4 6.4 +/- 31.3 cm/s, respectively), as did the deceleration slope of the early diastolic filling (from -151 +/- 67 to -210 +/- 107 cm/s(-2)), whereas no changes were found in the ratio between E(max) and A(max), the deceleration time of early diastolic filling, or the velocity time integrals of early or late diastolic filling. These changes in the Do ppler flow profile during adenosine infusion can be attributed to the increased heart rate and stroke volume. We conclude that adenosine may cause ischemia in some patients after coronary artery bypass surgery without causing obvious changes in regional LV wall motion or diastoli c function.