Acute mitral isthmus block during catheter ablation with vein of Marshall ethanol infusion: Angiographic considerations.

BACKGROUND: Achieving bidirectional mitral isthmus block is still challenging. Conventional ablation methods involve radiofrequency applications on the endocardial aspect of the lateral mitral isthmus, and often epicardial applications inside the coronary sinus. AIM: To evaluate the impact of the systematic use of ethanol infusion in the vein of Marshall on the achievement of acute mitral isthmus block of additional epicardial component lesion. METHODS: We evaluated patients referred to two centres for long-standing persistent atrial fibrillation ablation or recurrent peri-mitral flutter. All patients had pulmonary vein isolation and mitral isthmus line using ethanol infusion in the vein of Marshall for the first procedure and additional radiofrequency ablation lesion if necessary. For redo procedures, additional ablations (atrial lines and complex fractionated atrial electrogram ablations, if needed) were also performed. RESULTS: We included 149 patients, and ethanol infusion in the vein of Marshall was not performed in 27 patients (18%). Among 122 patients, 115 had long-standing persistent atrial fibrillation (94.2%) and seven had peri-mitral flutter (5.8%). The mean duration of continuous atrial fibrillation was 53 months before ablation. Acute bidirectional mitral isthmus block was obtained in 115 (94.2%) of the 122 patients who received ethanol infusion in the vein of Marshall (77% when considering the total population). The mean radiofrequency delivery time to obtain mitral isthmus block was 2.6minutes for the endocardial mitral isthmus radiofrequency ablation and 2.6minutes for the epicardial mitral isthmus radiofrequency ablation. Failure to obtain mitral isthmus block was associated with increased mitral isthmus length and left atrial dilation. No major complications related to ethanol infusion in the vein of Marshall were observed. CONCLUSION: Ethanol infusion in the vein of Marshall, when feasible (82%), was a safe approach to obtaining a high success rate (94%) of acute bidirectional endocardial and epicardial mitral isthmus block.

Intracoronary administration of darbepoetin-alpha at onset of reperfusion in acute myocardial infarction: results of the randomized Intra-Co-EpoMI trial.

BACKGROUND: Several trials investigating erythropoietin as a novel cytoprotective agent in myocardial infarction (MI) failed to translate promising preclinical results into the clinical setting. These trials could have missed crucial events occurring in the first few minutes of reperfusion. Our study differs by earlier intracoronary administration of a longer-acting erythropoietin analogue at the onset of reperfusion. AIM: To evaluate the ability of intracoronary administration of darbepoetin-alpha (DA) at the very onset of the reperfusion, to decrease infarct size (IS). METHODS: We randomly assigned 56 patients with acute ST-segment elevation MI to receive an intracoronary bolus of DA 150 µg (DA group) or normal saline (control group) at the onset of reflow obtained by primary percutaneous coronary intervention (PCI). IS and area at risk (AAR) were evaluated by biomarkers, cardiac magnetic resonance (CMR) and validated angiographical scores. RESULTS: There was no difference between groups regarding duration of ischemia, Thrombolysis in Myocardial Infarction flow grade at admission and after PCI, AAR size and extent of the collateral circulation, which are the main determinants of IS. The release of creatine kinase was not significantly different between the two groups even when adjusted to AAR size. Between 3-7 days and at 3 months, the area of hyperenhancement on CMR expressed as a percentage of the left ventricular myocardium was not significantly reduced in the DA group even when adjusted to AAR size. CONCLUSION: Early intracoronary administration of a longer-acting erythropoietin analogue in patients with acute MI at the time of reperfusion does not significantly reduce IS.