Quantitative beat-to-beat analysis of heart rate dynamics during dipyridamole echocardiographic test [ECG analysis]

The authors measured heart rate variability (HRV) during dipyridamole test (DET) in 36 patients with suspected coronary artery disease (CAD) who underwent coronary angiography for chest pain evaluation. The authors considered Group A: no CAD and negative DET results; Group B: CAD and negative DET; Group C: CAD and positive DET. After dipyridamole, in Group B and C, HRV measures of cardiac vagal control decreased and sympathetic activity increased; differently, in Group A all components of HRV decreased. Therefore, in CAD patients dipyridamole infusion induced a parasympathetic withdrawal with sympathetic predominance despite a negative DET. HRV analysis seems to be able to detect this autonomic disturbance, improving the diagnostic accuracy of DET in patients with suspected CAD.