Autonomic neurocardiogenic syndrome is stonewalled by the universal definition of myocardial infarction

Myocardial infarction(MI)is defined as myocardial cell death due to prolonged myocardial ischemia.Clinically,troponin rise and/or fall have become the“defining feature of MI”according to the universal definition of MI(UD-MI).Takotsubo syndrome(TS)and TS-related disease conditions also cause troponin elevation with typical rise and/or fall pattern but through a mechanism other than coronary ischemia.By strict application of the clinical diagnostic criteria for type-1 MI,type-2 MI,type-3 MI,and MI with non-obstructive coronary arteries according to the UD-MI including the fourth one published recently,TS and most of the 26 other causes of troponin elevation mentioned in the fourth UD-MI may erroneously be classified as MI.The existing evidence argues for the case that TS by itself is not a MI.Hyper-activation of the autonomic-sympathetic nervous system including local cardiac sympathetic hyper-activation and disruption with nor-epinephrine churn and spillover is the most probable cause of TS.This autonomic neuro-cardiogenic(ANCA)mechanism results in myocardial“cramp”(stunning),the severity and duration of which depend on the degree of the sympathetic-hyperactivation and nor-epinephrine spillover.The myocardial cramp may squeeze the cytosolic free troponin pools causing mild to moderate troponin elevation in TS and TS-related disease conditions.This ANCA syndrome,which has hitherto been enveloped by the UD-MI over more than one decade,may occur in acute,recurrent,and chronic forms.In this critical review,the controversies of UD-MI,evidence for ANCA syndrome,and a hypothetical mechanism for the troponin elevation in ANCA syndrome are provided.

A Novel guide extension assisted stenting technique for coronary bifurcation lesions

A challenging technical scenario frequently encountered in a percutaneous coronary intervention of a coronary bifurcation lesion(CBL)is stent implantation of only the stenosed segment without compromising the other two normal segments in non-true bifurcation lesions.Another is precise stent implantation covering the side branch ostium without leaving excessive stent metal at the other two segments of a bifurcation lesion in complex true bifurcation lesions.The aim of this study was to describe a novel stenting technique for both non-true and true CBLs by using a guide extension catheter(GuideLiner).With the assistance of a guide extension catheter mounted on both the main and the side-branch guidewires and with its intubation down to the bifurcation carina,a stent can be implanted in the side branch segment or distal main segment of the bifurcation lesion appropriately without compromising the other two segments of the coronary bifurcation.Stent implantation is described in three bifurcation lesions in three cases and shown in detail with illustrative figures.The technique facilitates side-branch only stenting in side-branch mono-ostial(medina 0,0,1)CBL or only the distal main segment in distal mono-ostial(medina 0,1,0)CBL without compromising the other two remaining segments when using the onestent technique in non-true CBLs without leaving unnecessary excessive stent metal at the bifurcation site and when using a two-stent technique in complex true bifurcation lesions(tri-ostial or medina 1,1,1).Consequently,through optimizing stent deployment,the technique may have the potential to reduce the risk of subacute stent thrombosis and future in-stent restenosis.The most appropriate lesions suitable for the technique,and some other practical tips are also described.