Click on image to view larger version.

Figure 2 Electrocardiogram (upper panel) and finger plethysmographic recording (lower panel) after initiation of enhanced external counterpulsation (EECP). Enhanced external counterpulsation leads to an increase in diastolic pressure (diastolic augmentation) and a decrease in systolic pressure (systolic unloading). The magnitude of EECP-induced hemodynamic changes is commonly assessed by measuring the diastolic-to-systolic effectiveness ratio, which is calculated by dividing the peak diastolic amplitude by the peak systolic amplitude of the finger plethysmographic signal.