Towards refining of the proposed ECG-based index of coronary microvascular resistance (ECGMVR).

Assessment of the coronary microcirculation via noninvasive indices of coronary microvascular resistance (MVR), based on coronary angiography (AngioMVR) is currently implemented in patients undergoing coronary angiography, and it is employed by many laboratories. Recently, a proposal has been presented of a new index of MVR, based on the duration of the transient electrocardiogram repolarization and depolarization changes emerging during coronary angiography (ECGMVR). It is paramount that the ECGMVR, which does not require any special expertise, new equipment, additional personnel and costs, or prolongation of the catheterization procedure, undergoes correlation with currently utilized indices of AngioMVR, the TIMI frame count index, and the invasive indices assessing the coronary epicardial and microvasculature states, for its validation. Some additional insights are also included in the present communication for the refinement of ECGMVR implementation.