Introduction Stent failure and particularly in-stent restenosis (ISR) remains a common presentation following percutaneous coronary intervention (PCI). Reported data suggests rates of up to 30% following bare metal stenting and 5–10% following drug eluting stents. A number of patient, procedure and stent characteristics are known to increase the risk of ISR. Little is known about ISR amongst patients in the Irish health care setting. We aimed to investigate the patient characteristics, management and outcomes for those presenting with ISR to a large tertiary referral centre. Methods We conducted a retrospective cohort study on consecutive patients presenting with ISR to our tertiary cardiology centre between 2020 to 2021. Patient demographics, type of percutaneous intervention performed and clinical outcomes were recorded in a dedicated database. Results Between 2020 and 2021, 134 cases of ISR were treated in our institution. The median time from index procedure to ISR treatment was 77 months (IQR 22–152). 82.8% of patients were male and mean age was 68.9 years (SD 10.1 years). Patients had a high rate of cardiovascular risk factors including, diabetes 35.1%, hypertension 91.8% and smoking 84.3%. Prior myocardial infarction was common 71.6% and 17.2% had a history of coronary artery bypass grafting. The original stent data was available on 63 patients (47%), all of which were implanted with drug eluting stents. Clinical presentation was with stable angina in 47%, non ST-elevation myocardial infarction 27.6%. ST-elevation myocardial infarction accounted for 11.2% (in the setting of acute stent thrombosis) and unstable angina 11.9%. The right coronary artery (RCA) was most commonly affected, accounting for 38.8% of presentations, the left anterior descending (LAD) was associated with 30.6% of cases, left circumflex artery (LCx) in 14.2%, 5% in saphenous vein grafts and 5.9% involving the left main stem (LMS). Mehran ISR classification was type IC (focal stenosis) in 37.3%, type II (diffuse intrastent) in 26.9%, type IV (occlusive) in 12.7%, type IB (stent margin) in 9.5%, type ID (multifocal intrastent) in 3.7% and type III (diffuse proliferative extending beyond stent margin) in 3%. Percutaneous coronary intervention of the ISR was guided by intracoronary imaging in 38.8%; with 38.5% of these using optical coherence tomography (OCT) and 61.5% using intravascular ultrasound (IVUS). Drug coated balloon application was the most common management strategy (69.4%), and further stenting with drug eluting stents was utilised in 25.4%. Median follow up was 16.6 months (IQR 4–22.9). At 1 year follow up there were 15 deaths (11.2%), 6 myocardial infarctions (4.5%) and 26 required further target lesion revascularisation (19.4%). Conclusion Instent restenosis continues to be common, and accounts for a large proportion of the cath lab workload. Similar to previous studies, a high prevalence of cardiovascular risk factors, particularly diabetes were found among our patients. Additionally, acute coronary syndrome was the presenting event in nearly half of the population, highlighting the non-benign nature of this disease. Despite imaging guided treatment of ISR, a high proportion of patients required further intervention on the ISR vessel and further work is required to identify risk factors for recurrent ISR.

Background Implantable Cardioverter Defibrillators (ICDs) have been proven to reduce the incidence of sudden cardiac death in both primary and secondary prevention populations. However, it is recognised that shock treatment can be negatively experienced by patients and there is recognition that this may be inappropriate in end-of-life and palliative care situations. Despite the fact that both Heart Rhythm Society and European Heart Rhythm Association Consensus documents both outline the appropriateness of deactivation of ICD shock therapy in these situations, research has shown that 27% of patients receive shock therapy in the last month of life (Goldstein et al 2004). Aim The aim of the study was report on the single centre experiences of a protocol for deactivation of ICDs and Cardiac Resynchronisation Therapy Defibrillators (CRT-Ds) in a large tertiary referral centre. Methods This large tertiary referral centre has had a protocol for Deactivation of ICDs in End-of-Life Situations since late 2009 (figure 1). ICD and CRT-D records for patients implanted in this centre were analysed for deaths which occurred between Jan 2010 and Dec 2018. Follow-up records were analysed for devices which were deactivated prior to death.Abstract 4 Figure 1 Protocol for deactivation of ICDs in end-of-life situations Protocol for deactivation of ICDs in end-of-life situations Results A total of 149 patients with ICDs or CRT-Ds died between Jan 2010 and Dec 2018 which represented 23.8% of the ICD and CRT-D population implanted in the centre. 44 patients had the shock therapy of their device deactivated prior to death. This represented 29.4% of the patients with ICDs or CRT-Ds who died during this period. The numbers of deactivations are showing an upward trend, from one deactivation in 2010 to twelve deactivations in 2018 (figure 2).Abstract 4 Figure 2 Number of device deactivations by year Number of device deactivations by year Of these 44 patients, device deactivation occurred in the following locations 79% in the implanting centre 11.9% in the patients home or nursing home 6.8% in hospice settings 2.3% in an outlying hospital It was noted that the family were present at the time of deactivation in 32% of cases. All deactivations occurred less than 7 days from the date of the patient’s death. All were carried out by Cardiac physiologists and performed in less than 24 hours. Where deactivation occurred in the community, the Cardiac Physiologist was met by a palliative care nurse or GP. In one case the hospital Heart Failure Nurse travelled with the Cardiac Physiologist. In two further cases, requests for deactivation were received but could not be acted upon before the patient’s death. Both of these cases were from the community. Conclusion Deactivation of shock therapy in ICDs and CRT-Ds in end-of life situations is increasing and this service can be delivered by Cardiac Physiologists. Whilst the vast majority of deactivations occur in the implanting centre, over one in five occur in other settings and services should be designed to meet this need. The fact that only 29.4% of patients with ICDs or CRT-Ds implanted had their device deactivated, coupled with the fact that all deactivations occurred less than 7 days prior to date of death, suggest that significant education around this issue with other healthcare providers needs to take place.

BackgroundImplantable Loop Recorders (ILRs) provide long term ECG monitoring for patients for a number of presentations. It has a Class I indication for investigation of recurrent syncope (ESC 2018 Syncope Guidelines) and a Class IIa indication for documenting silent atrial fibrillation in patients with a cryptogenic stroke (ESC 2016 Atrial Fibrillation Guidelines). The miniaturisation of ILRs and their “injectable” nature has increased their clinical use. The addition of remote monitoring with alert notification allows for early detection of significant events in these patients, however false activation of automatic detection algorithms results in inappropriate remote transmissions and unnecessary use of Cardiac Physiologist time.AimThe aim of the study was to look at the true and false activation rates from patients implanted with ILRs from a specific manufacturer, the number of those activations, and to classify the reason for those activations.MethodsThe transmissions from patients implanted with ILRs from a single manufacturer between Aug 2017 and Jun 2018 were analysed retrospectively. All transmissions from the date of implant to Jul 2019 were analysed. Where there was any doubt about the nature of a detection an opinion of a Cardiologist was sought. Data around indication for implant, the number and nature of true and false activations were recorded. For false activations, the reasons for these were also noted.Results41 ILRs were implanted in this period in 21 males and 20 females. Ages at time of implant ranges from 17.93–79.78 yrs (avg 49.41 yrs). 80% were implanted for investigation of syncope, 7% for palpitations, 5% for AF detection and 7% for other indications. The total number of monitoring days across the total patient population was 3185 days with the average monitoring period being 77.68 (range 10–224) days. 23 pts (56.1%) made a total of 93 patient activated events. Only two patients’ recordings showed significant findings, an SVT and a broad complex tachycardia. 6 pts’ (14.6%) ILRs automatically detected a total of 37 true arrhythmias, 26 AF, 1 pause and 10 SVT events 26 pts’ (63.4%) ILRs automatically detected a total of 46,604 false arrhythmia detections. This equated to 14.63 false transmissions per day of monitoring. The types and reasons for false activations are shown in table 1.ConclusionIn this analysis of episodes sent by ILRs on remote monitoring 91.8% of episodes were due to false triggering of automatic device detection. In 96.8% of these cases this was due to undersensing of the QRS complex by the ILR. This analysis highlights the significant burden of remote follow-up of ILRs, particularly that of false triggering of automatic device detection algorithms. It also highlights that over 96% of false triggering are due to undersensing, highlighting the importance of achieving good amplitude QRS signals at implant.

Introduction Cardiac implantable electronic devices (CIED) are associated with low rates of procedure-related complications but many of these complications are associated with significant morbidity and prolonged hospitalisations. The aim of this study was to perform a retrospective ‘real world’ review of CIED complication rates in a tertiary centre in the West of Ireland and compare rates to a multi-centre CIED complication registry, the REPLACE registry1. Methods All patients who received a new device implant (ICD, PPM, CRT) or revision of an existing implant from 01/01/2016 to 31/12/2016 at Galway University Hospital were included (table 1). Data on complications associated with the procedure were collected from patient records including electronic discharge summaries, cardiothoracic surgery records, catheterisation laboratory log book records, patient clinical files and the pacing registry G-Pace. Complication rates were compared to the REPLACE registry1 data using the same major and minor complication criteria (table 2). Results 373 patients were included in the analysis (male = 257 (69%), female = 116 (31%)) and were followed up for an average of 28.6±7.9 months. The mean age was 73±13 years at the time of the procedure. 106 (28%) patients were transfers from peripheral hospitals and 76 (20%) of these patients returned to their referring centre on the same day. 156 (42%) patients were electively admissions, the remaining 111 (30%) patients were acutely admitted. 73 patients developed (19.6%) complications in the follow up period. Of these, 30 (8%) were early (i.e. before discharge, range 0–4 days) and the remaining 43 (11.5%,) occurred post-discharge. 12 (3%) occurred at 0–1 months, 9 (2%) at 1–3 months, 13 (3%) at 3- 12 months, and 9 (2%) >12 months. The complications with the highest rates (>1%) included lead revision (n=23, 8.6%), pneumothorax (n=8, 4.8%), device infection (n=9, 2.4%) and haematoma/swelling (all n=9, 2.4%). One patient (0.3%) died from RV perforation. Conclusion Overall the CIED major complication rate at our centre is comparable to that of the REPLACE registry1. Major complications such as lead revisions, pneumothorax, infection and haematoma were numerically higher when compared to the same study. Our findings illustrate the risk and variety of complications that can occur with these procedures and highlights the need ongoing strategies to minimise the risks of these complications.

Background Cardiac telemetry plays an important role during acute hospitalisation for rhythm monitoring and the diagnosis of arrhythmias. However it requires infrastructure, telemetry units, monitoring staff and bed days with their associated costs. There can be significant delays in awaiting telemetry for low to moderate risk patients and due to demand telemetry periods may be sub-optimal. Alarm fatigue amongst monitoring nurses is also recognised. To address telemetry waits, our institution commenced a Rapid Ambulatory Physiologist-led Discharge facilitating or RAPID Monitoring service, using R-test4 monitors (Novacor UK) in Jan 2019. Patients can wear these for 72hrs and can be discharged with them on. They are analysed immediately on return with teams being informed of results. Aim This study reports on the usefulness of this alternative to inpatient telemetry. Methods Data was collected, and continues to be collected, prospectively including -indication -number and type of significant findings-number and type of contributing findings (potential cause of initial presentation) -representation/admission rate at 30 days -length of stay -time from referral to monitor being fitted. The following clinical presentations were indicated for the RAPID Monitoring service -syncope/presyncope-TIA-Stroke Work-up-Palpitations and indications below were excluded and referred for inpatient telemetry in line with AHA Guidelines -Chest pain and ACS -known acute ventricular arrhythmias-electrolyte imbalances-atrial fibrillation with rapid ventricular response. Results A total of 117 patients underwent RAPID monitoring between Jan and Mar 2019, representing 351 days of monitoring. The median time to fitting of the monitor from referral was 2.8 hours. Syncope/presyncope was the indication in 54% of cases, stroke and TIA accounting for 20% for referrals and palpitations being the reason in 16% of cases (figure 1) Significant findings on RAPID monitoring were seen in 26% of cases. These findings included atrial tachycardia (47%), atrial fibrillation or flutter (23%) and pauses >2.0s (23%). Contributing findings, a potential cause for the presentation, were found in 8% of cases. Of those patients, pauses were the most common finding (44%) followed by atrial tachycardia and atrial fibrillation, both 22% of findings (figure 2) Median and average length of stay were 2.0 and 5.3 days, respectively. Six patients represented acutely within 30 days (5.1%), 4 to ED, 2 to AMU with 2 requiring admission. (Note seven months of data will be available by October).Abstract 16 Figure 1 Rapid Monitoring Indications Rapid Monitoring IndicationsAbstract 16 Figure 2 Significant and contributing findings on RAPID monitoring Significant and contributing findings on RAPID monitoring Conclusion The diagnostic yield was acceptable with significant findings being seen in 26% of patients and potential diagnostic findings in 8%. This compares well with a 5% yield in unselected syncope patients (AHA Update to Practice Standards for Electrocardiographic Monitoring in Hospital Settings 2017). Monitors were fitted quickly (median wait of 2.8 hours) and provided 72hrs of monitoring. Patients who were seen in the RAPID service had a median and average LOS (2.0 and 5.3 days) which was less than nationally reported (3.0 and 7.1 days) in 2018. The 30 day acute readmission rate of 5.1% is 54.8% lower than the national average of 11.3% (HSE 2018 Performance Reports) A RAPID monitoring service is a viable and safe alternative to inpatient telemetry, reducing waits for and demands on this service and facilitating earlier discharge.

Background Cardiac arrest due to ischaemia is frequently the first manifestation of cardiovascular disease. We sought to describe the characteristics and outcomes of patients admitted to the Intensive Care Unit (ICU) with a diagnosis of cardiac arrest secondary to acute coronary syndrome (ACS).Methods We performed a retrospective analysis of patients admitted to the intensive care unit over a 4 year period. Baseline demographic characteristics, the use of therapeutic hypothermia, rates of percutaneous coronary intervention, co-morbidities and baseline left ventricular function were all documented. Outcomes included Glasgow Coma Scale (GCS) at time of discharge from the ICU, survival to hospital discharge, 6 months survival and left ventricular function at 6 months.Results We identified 31 admissions to the ICU following cardiac arrest due to ACS during the study period. 71 % of patients survived to hospital discharge and all of these were still alive at 6 months. 65 % had good neurological function (GCS[13) when discharged from ICU. Mean left ventricular ejection fraction remained stable at 6 months.Conclusions A significant proportion of patients admitted to the intensive care unit with a diagnosis of cardiac arrest secondary to acute coronary syndrome survive to hospital discharge with meaningful recovery in neurological and cardiac function.

The majority of cardiac arrests occur due to cardiovascular etiology. Targeted temperature management (TTM) (32–34 °C) is a part of the standard post arrest care. We hypothesized that lower body temperature may lead to reduced cardiac metabolic demand and potentially have a beneficial effect on myocardial function.

One aim of integrative neurophysiology is to understand the relationship between neuronal activity and normal evolution of other physiological parameters. In this respect, anaesthetics or paralyzing agents, that have been shown to have a significant effect on several vital physiological processes, can be seen as a real problem for the interpretation of observations. Eletrophysiological recording in awake animals avoids this problem. Recordings in forebrain areas are now used routinely but a number of specific difficulties have limited their application to the medullary areas. In this paper, we describe a preparation that allows us to simultaneously record neuronal activity in the dorsal brainstem and respiratory activity in awake rats, while applying different types of respiratory challenges.

Deformation of the upper airway (UA) by negative transmural pressure alters the activity of UA mechanoreceptors, causing a reflex increase in UA muscle activity. Topical anesthesia of the UA mucosa, which greatly reduces this reflex response, causes an increase in UA resistance during stage 2 sleep. We hypothesized that topical anesthesia of the UA mucosa would predispose to UA instability at sleep onset and, therefore, examined the effect of UA anesthesia on pharyngeal resistance (Rph) in stage 1 sleep. Eleven normal, healthy volunteers were instrumented to record standard polysomnographic variables, respiratory airflow, and UA pressure at the nasal choanae and the epiglottis. Subjects were permitted to sleep until stable stage 2 sleep was reached and were then awoken. This procedure was repeated three times to obtain reproducible wake-sleep transitions. The UA mucosa was then anesthetized with 10% lidocaine to the oropharynx and laryngopharynx, and the pharyngeal mechanics were studied during the subsequent wake-sleep transition. Three subjects were excluded because of failure to resume sleep postanesthesia. Rph was significantly higher after anesthesia during stage 1 sleep [2.88 +/- 0.77 cmH(2)O.l(-1).s (mean +/- SE)] compared with control (0.95 +/- 0.35 cmH(2)O.l(-1).s; P < 0.05), but there was no difference during wakefulness. Furthermore, there was a significant rise in Rph at wake-to-sleep transitions and a significant fall in Rph at sleep-to-wake transitions after anesthesia (P < 0.05) but not in the control condition. We conclude that sensory receptors in the UA mucosa contribute to the maintenance of UA patency at wake-sleep transition in normal humans.

Upper airway (UA) muscle activity is stimulated by changes in UA transmural pressure and by asphyxia. These responses are reduced by muscle relaxation. We hypothesized that this is due to a change in afferent feedback in the ansa hypoglossi and/or superior laryngeal nerve (SLN). We examined 1) the glossopharyngeal motor responses to UA transmural pressure and asphyxia and 2) how these responses were changed by muscle relaxation in animals where one or both of these afferent pathways had been sectioned bilaterally. Experiments were performed in 24 anesthetized, thoracotomized, artificially ventilated rats. Baseline glossopharyngeal activity and its response to UA transmural pressure and asphyxia were moderately reduced after bilateral section of the ansa hypoglossi (P < 0.05). Conversely, bilateral SLN section increased baseline glossopharyngeal activity, augmented the response to asphyxia, and abolished the response to UA transmural pressure. Muscle relaxation reduced resting glossopharyngeal activity and the response to asphyxia (P < 0.001). This occurred whether or not the ansa hypoglossi, the SLN, or both afferent pathways had been interrupted. We conclude that ansa hypoglossi afferents tonically excite and SLN afferents tonically inhibit UA motor activity. Muscle relaxation depressed UA motor activity after section of the ansa hypoglossi and SLN. This suggests that some or all of the response to muscle relaxation is mediated by alterations in the activity of afferent fibers other than those in the ansa hypoglossi or SLN.

The patency of the upper airway is dependent on the sustained activity of upper airway muscles, in particular the genioglossus (GG) muscles which act to protrude the tongue. Obstructive sleep apnea syndrome (OSAS) is a common and serious disorder in which this mechanism fails, resulting in frequent collapse of the airway during sleep. The properties of the upper airway muscles are therefore of interest in both normal and OSAS subjects, so that their role in the pathogenesis of OSAS can be better understood. Electromyography (EMG) is an important tool for assessing muscle activity and has been used in many GG studies. We have designed a new appliance incorporating a surface electrode array for GG EMG recording. The electrode configuration enables estimation of muscle fibre conduction velocity (CV), an important parameter for monitoring muscle fatigue, which has not been studied before in the GG. The appliance is also designed to provide accurate and repeatable placement of electrodes. Preliminary results presented demonstrate the performance of our appliance, which will now be used to measure GG CV in a range of fatiguing conditions.