Diagnostic Yield of Implantable Loop Recorders in Patients with Unexplained Syncope

Abstract

of patients in sinus rhythm at one and two year follow up. These results are comparable to international reports. Follow up at 12 months Follow up at ≥24 months Total (n= 65) Paroxysmal AF (n= 37) Nonparoxysmal AF (n= 28) Total (n= 36) Paroxysmal AF (n= 20) Nonparoxysmal AF (n= 16) Success without drugs Single procedure (%) 53.8 56.8 50.0 50.0 55.0 43.8 Success with or without drugs Single procedure (%) 58.5 59.5 57.1 50.0 55.0 43.8 Success without drugs ≥1 procedure (%) 69.2 67.6 71.4 69.4 70.0 68.8 Success with or without drugs ≥1 procedure (%) 89.2 91.9 85.7 86.1 90.0 81.3 http://dx.doi.org/10.1016/j.hlc.2012.03.098 Diagnostic Yield of Implantable Loop Recorders in Patients with Unexplained Syncope J. Swampillai ∗, R.F. Allen, S. Levings, M.R.Webber, C.M. Wade, M.K. Stiles, S.C. Heald Department of Cardiology, Waikato Hospital, Hamilton, New Zealand Background: The implantable loop recorder (ILR) is a subcutaneous, electrocardiographic monitoring device used for diagnosis in patients with recurrent, infrequent Use of Exercise Tolerance Test in Intermediate Risk nonST Elevation Acute Coronary Syndrome P. Tamuno ∗, J. Mazhar, J. Swampillai, V. Pera, A. Kerr, G. Devlin Department of Cardiology, Waikato Hospital, Hamilton, New Zealand Background: Exercise tolerance test (ETT) is recommended for initial risk stratification in patients with Non ST Elevation Acute Coronary Syndrome (NSTEACS) in the absence of high risk features. We reviewed current practice at Waikato Hospital, the regional tertiary centre. Methods:FromtheACUTEPREDICTregistrywe identified 716 patients admitted with NSTEACS and TIMI score 0–4 between January 2008 and January 2010. After excluding143patientswhoweremanagedmedically (20%)due to co-morbidities, the remaining 573 patients were analysed in two groups: Group A had ETT prior to angiography; Group B had angiography without ETT. Results: There were 244 (43%) patients in Group A (mean age 64± 12 years, 72% males) and 329 (57%) in Group B (mean age 64± 13 years, 66% males). Compared togroupA,GroupBhadmorepatientswithTIMI score 3–4 (63%vs. 53%,P= 0.02) andNSTEMI (66%vs. 44%,P≤ 0.01). Results are summarised in the tables below. Only 20% of patients risk-stratified by ETT did not undergo inpatient angiography (Tables 1 and 2). symptoms with a suspected arrhythmic aetiology. We aimed to establish the diagnostic yield of ILR in patients with unexplained syncope. Methods: We identified all patients who had an ILR implanted at Waikato Hospital from March 2007 to November 2011. Previous investigations, arrhythmias detected by the device and outcomes were recorded. Results: Thirty-one patients (17 men; mean age 46± 24 years) underwent ILR implantation. The mean number of cardiac investigations prior to ILR was 4± 1; duration of implant 16± 12 months. Arrhythmias were detected in 13 patients; eight tachycardias, five bradycardias. Time to diagnosis was 7± 6 months and specific treatment was guided by ILR analysis in these patients. Pacemakers were implanted in four patients, two received implantable cardioverter defibrillators, two were given anti-arrhythmic drugs, four had an electrophysiological study (two were normal and two underwent catheter ablation). Neurocardiogenic syncope was diagnosed in one patient and symptoms resolved. Sinus rhythm was documented during syncope in five patients. Death from non-arrhythmic causes occurred in twopatients (onemyocardial infarction and cardiogenic shock, one stroke). No arrhythmias have been detected so far in 11 patients remaining under follow up (mean implant duration 9± 7 months). Conclusion: More than half of patients had an arrhythmic causeof syncopediagnosed (13) or excluded (5) by ILR. This confirms their usefulness in selected patients with unexplained syncope despite normal preliminary investigations. http://dx.doi.org/10.1016/j.hlc.2012.03.099 Table 1. Summary of coronary interventions and outcomes. Group A N= 244 Group B N= 329 P value Inpatient angiogram 195 (80%) 329 (100%) <0.01 PCI 109 (45%) 180 (55%) 0.02 CABG 23 (9%) 24 (7%) NS Length of stay in days (mean±SD) 6.8± 6 6.1± 5 0.09 Stroke/TIA (in-hospital) 0 3 Death (in-hospital) 1 1 Table 2. Angiograms performed in relation to ETT results. Positive ETT N= 167 (68%) Negative ETT N= 42 (18%) Inconclusive ETT N= 35 (14%) In-patient angiogram, N (%) 159 (95%) 10 (24%) 26 (74%) Angiogram in 6-month F/U, N (%) 6 (4%) 7 (17%) 2 (6%) Conclusions: The majority of patients admitted with NSTEACS and TIMI score ≤4 underwent inpatient angiography regardless of the use of ETT as a risk stratification tool for intermediate risk scores. No difference was evident in early events. http://dx.doi.org/10.1016/j.hlc.2012.03.100