Prehospital electrocardiogram shortens ischaemic time in patients with ST-segment elevation myocardial infarction.

INTRODUCTION: Total ischaemic time should be shortened as much as possible in patients with ST-segment elevation myocardial infarction (STEMI). This study evaluated whether prehospital 12-lead electrocardiogram (ECG) could shorten system delay in STEMI management. METHODS: From November 2015 to November 2017, 15 ambulances equipped with X Series Monitor/ Defibrillator (Zoll Medical Corporation) were used in the catchment area of Queen Mary Hospital, Hong Kong. Prehospital ECG was performed for patients with chest pain; the data were tele-transmitted to attending emergency physicians at the Accident and Emergency Department (AED) for rapid assessment. Data from patients with STEMI who were transported by these 15 ambulances were compared with data from patients with STEMI who were transported by ambulances without prehospital ECG or who used self-arranged transport. RESULTS: Data were analysed from 197 patients with STEMI. The median patient delay for activation of the emergency response system was 90 minutes; 12% of patients experienced a delay of >12 hours. There was a significant difference in delay between patients transported by ambulance and those who used self-arranged transport (P<0.001). For system delay, the use of prehospital ECG shortened the median time from ambulance on scene to first ECG (P<0.001). When performed upon ambulance on scene, prehospital ECG was available 5 minutes earlier than if performed in ambulance compartment before departure. Use of prehospital ECG significantly shortened AED door-to-triage time, AED door-to-first AED ECG time, AED door-to-physician consultation time, and length of stay in the AED (P<0.001 for all comparisons). CONCLUSION: Prehospital ECG shortened ischaemic time prior to hospital admission.

Triple wire technique for a bifurcation lesion and a subtotal occlusive lesion.

In a critical distal right coronary artery bifurcation lesion, the proximal course of the posterior descending artery was also subtotally occluded. The posterior descending artery gave rise to a small sidebranch just before the occlusion. In the subsequent revascularization procedure, the bifurcation lesion was double-wired. One wire was placed in the postero-lateral branch, and another wire was intended for placement in the posterior descending artery, but it repeatedly selected the sidebranch despite multiple shapings of the wire tip. While the second wire was deliberately kept in the sidebranch, a third wire was used and crossed the occlusive lesion without much difficulty. The second wire was then withdrawn and the revascularization procedure proceeded in the usual manner. The positioning of the second wire in the sidebranch significantly shortened the procedure.