PO-626-07 VALIDATION OF A PORTABLE DEVICE FOR HF-ECG IN ISCHEMIA DETECTION DURING CORONARY BALLOON INFLATION IN ANGIOPLASTY - BRINGING THE PHYSIOLOGY LAB TO THE BEDSIDE !

Abstract

High frequency QRS (HfQRS) analysis for rapid assessment of myocardial ischemia has never been evaluated owing to the logistical challenges of signal recording. We aim to evaluate, in a pilot study, the correlation between the HFQRS changes recorded on a novel wearable Sydäntek 12 lead ECG patch with balloon inflation induced ischaemia. To document utility of a portable device, Sydäntek, in ECG and HFECG during multiple balloon inflations. 10 patients (M:F = 8:2) undergoing coronary intervention for medically refractory chronic stable angina were screened for enrollment into the study ; 9/10 patients underwent the final recording. 1 patient was excluded owing to signal noise in the device due to reluctance in chest preparation. The mean recording time per case was 60+/-15 mins. ECG including HfQRS was recordable continuously during all intended times, using Sydäntek at 2k samples/secs. In 33 balloon inflation ischemia episodes , changes were seen on the HFQRS onset ∼ 10 secs, offset ∼45 secs after deflation . No significant changes were seen in the conventional ECG analysed for these upto ∼45 secs . Decrease in the amplitude of the HFQRS, and decrease in the real time RMS voltage of QRS in leads V2-V5 and the presence of RAZ ( reduced amplitude zone ) were considered to be changes suggestive of ischemia. RAZ disappeared ∼45 secs after the balloon deflation. The mean total ischemic was 1 +/-0.5 min per patient per balloon inflation. In this study , all 9 of the conventional ECGs were reported independently by 2 docs as not having significant ST-T changes of ischaemia. RAZ presence in HFQRS was seen in all 33 of complete coronary artery occlusion by balloon, in our study .There was reduction in the amplitude of HFQRS(mean 12+/-1 μV) and RMSv2-v5 (mean 7+/-0.5 μV) from the baseline during the inflation. Post intervention, both of the above parameters had a mean increase of 22+/-1 μV and 10+/-0.3 μV respectively. HFQRS measured using our novel, portable real time 12 lead ECG recording patch can reliably detect onset of coronary ischemia in a complete coronary occlusion even in absence of ST -T changes in 12 lead ECG . We submit this proof of concept for use in detecting ischemia in a variety of clinical situations including chest pain triage and post intervention monitoring.