P2280Incidence and predictors of alarms in patients with wearable cardioverter defibrillator (WCD) - results of the Austrian WCD Registry

2019 ◽  
Vol 40 (Supplement_1) ◽  
Author(s):  
U Rohrer ◽  
M Manninger ◽  
T Odeneg ◽  
C Ebner ◽  
D Moertl ◽  
...  

Abstract Background The wearable cardioverter-defibrillator (WCD) is a treatment option for patients at high risk for ventricular arrhythmia, either if the risk is potentially reversible or if an implantable cardioverter defibrillator (ICD) implantation is currently not possible. Methods We performed a retrospective analysis of all alarms in the cohort of the Austrian WCD registry between 2010 and 2018. Type of arrhythmias was assessed by independent review of two cardiologists. Results 25.540 automatically recorded ECGs in 605 patients (68%) were analyzed. 1125 ECGs showed sustained ventricular arrhythmias in 117 patients, 65 ECGs showed non sustained VTs. 24.415 ECGs in 488 patients showed inadequate alarms Reasons for inadequate alarms were artefacts (97%), pacemaker or t-wave oversensing (0,3%) and in 2,3% atrial fibrillation or SVTs. 5860 manually recorded ECGs in 608 patients (68%) were analyzed. 298 (5%) of these ECGs showed following arrhythmias: atrial fibrillation (34,7%), SVTs (28%), sinustachycardia (10,7%), non sustained VTs (12%) and sustained VTs or sustained slow VTs (6,7%), premature ventricular beats or bradycardia was identified in 8%. The remaining 5562 ECGs (95%) showed normal sinus rhythm. Of the 895 patients (60±14 years, 20% female), 34 (3,8%) received a total of 65 automatically triggered shocks (median 2; range 1–5). 31/895 (3.5%) patients received 57 appropriate shocks (median 1, range 1–5) for 49 arrhythmic events, whereas 7/895 (0.8%) patients received 8 inappropriate shocks (median 1, range 1–2). 44 events were successfully terminated with the first shock (85,7%) and 4 events were terminated with the second shock. In one patient, a shock treatment for VF was not successful. The time from event onset to shock was median 60 [40; 1187] sec. The median time from WCD prescription to a shock event was 8 days [1–151]. 23/ 34 patients (68%) received their first WCD shock within 30 days. Seven patients (0.8%) received a total of nine inappropriate shocks due to different reasons: artefacts (2 inappropriate shocks), non-shockable rhythms (asystole, weak action, 3 shocks) and atrial fibrillation with a bundle branch block in two cases. In one patient VF terminated spontaneously before the WCD treatment was delivered. Conclusion The WCD is an effective treatment option in patients with a high SCD risk but it also triggers a significant amount of alarms. Although many inadequate alarms occurred, adequate alarms led to arrhythmia detection such as in VT/VF events which were successfully terminated by the WCD in 3,4% of patients.

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
J Ehmsen ◽  
H Keller ◽  
C Stoellberger

Abstract Background The use of the Wearable Cardioverter Defibrillator (WCD) is recommended in national, European and American guidelines. However, there are almost exclusively data from the manufacturer's own data network. Independent data on the experience with the WCD are rare. Objective The aim of the retrospective study from one cardiologic department was to record efficiency, safety and compliance of the WCD. Patients and methods The study included all patients, to whom a WCD was described between 1.11.2010 and 1.5.2018 at one cardiologic department. Clinical data were obtained from the patients' records and the data about the WCD from the information network of the manufacturer. Results This study enrolled 66 patients, 51 males (77%) and 15 females (23%). The median age was 55 years (IQR: 45–63). They suffered from ischemic cardiomyopathy (n=33; 49%), dilated cardiomyopathy (n=12; 18%), myocarditis (n=7; 11%), explantation of an implantable cardioverter/defibrillator (ICD; n=5; 8%) and other indications (n=6; 9%). The median wearing time of the WCD was 73 days (interquartile range-IQR: 39–126), with median daily use of 22.91 h (IQR: 19.58–23.61). Among 38 patients with LVEF ≤35%, LVEF improved to ≥35% in 19 patients (50%) during WCD therapy. Over 1600 times the WCD detected a VT falsely. Four patients (8%) suffered from 212 non-sustained VT. One patient was successfully shocked because of ventricular fibrillation (appropriate shock rate: 1.5%). There were no inappropriate shocks. All patients, who wore the WCD, survived and one patient died when he did not wear the WCD. At the end of therapy 32 patients (48%) received an ICD. In terms of wearing time and events (shocks, arrhythmias, artifacts) there were no significant differences between patients receiving ICD and those who did not receive an ICD. Patients who received an ICD had a significantly lower LVEF after 3 months than patients who did not receive an ICD. Conclusion Our data confirm, that the WCD is safe and that the patients, who wear a WCD, have a high adherence. More than half of the patients with reduced LVEF improved their systolic function during WCD therapy, thus obviating the need for ICD implantation. Questions about the effectiveness of the detection algorithm remained open. Funding Acknowledgement Type of funding source: None


EP Europace ◽  
2001 ◽  
Vol 2 (Supplement_1) ◽  
pp. A48-A48
Author(s):  
A Przybylski ◽  
M Sterliński ◽  
M Lewandowski ◽  
M Pytkowski ◽  
A Kurowski ◽  
...  

Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Madhurmeet Singh ◽  
Krishna Alluri ◽  
Andrew Voigt ◽  
Norman Wang ◽  
Sandeep Jain ◽  
...  

Introduction: The wearable cardioverter-defibrillator (WCD) is approved for prevention of sudden cardiac death in patients with newly diagnosed cardiomyopathy and LVEF < 35% who do not yet meet criteria for implantation of an implantable cardioverter-defibrillator (ICD). While there are some data supporting WCD use in patients with ischemic cardiomyopathy (ICM), data in patients with nonischemic cardiomyopathy (NICM) are lacking. Methods: This was a retrospective review of outcomes for all NICM patients prescribed a WCD at a large tertiary academic center from 6/2004 - 1/2014 for a newly diagnosed cardiomyopathy and no prior sustained ventricular arrhythmia. During this time period, 454 patients were prescribed a WCD, of whom we excluded 161 patients with ICM. Results: The 183 (40%) patients with NICM consisted of 70% men, aged 57 +/- 15 years old, with mean EF 23% +/- 8% and LV end-diastolic dimension 4.5 +/- 2.8 cm. DM and HTN were prevalent (20% and 51%, respectively). At NICM diagnosis, 21% had LBBB and 36% had known history of AF. Patients wore the WCD for 13,124 patient-days, each averaging 72 +/- 55 days and with fairly high compliance (18.3 +/- 5.7 hours/day). Medication use consisted of 90% beta-blockers, 88% ACE inhibitors, 85% diuretics, 16% digoxin, and 17% anti-arrhythmic drugs. NSVT was documented in 42% of patients prior to WCD prescription. During follow-up, 60 (33%) patients improved LVEF to > 35%, obviating an indication for ICD implantation, whereas 79 (43%) patients received an ICD. The remainder died (n=17), were lost to follow-up (n=20), refused ICD implant (n=5), or are still wearing the WCD (n=2). No appropriate WCD shocks were delivered in any NICM patient, yet 3 inappropriate shocks were delivered (1.6%). Based on estimated rental costs provided by the manufacturer, the total cost of WCD use in this population was $1,449,360. Conclusions: In this large, tertiary care center registry of patients with newly recognized NICM, no patient received an appropriate shock from the WCD whereas several inappropriate shocks were delivered, despite nearly one-half of patients having documented significant ventricular ectopy. Given the significant expense and inconvenience of the WCD, its use in this population requires prospective study.


Circulation ◽  
2020 ◽  
Vol 142 (Suppl_3) ◽  
Author(s):  
Lawrenshey Charles ◽  
Abdullah Al-Abcha ◽  
Tyler Kemnic ◽  
Zulfiqar Qutrio Baloch

Introduction: Short QT syndrome (SQTS) is a very rare genetic disease of the electrical system of the heart which is associated with an increase risk of abnormal cardiac rhythms and sudden cardiac death. First described in 2000 with the first genetic mutation associated with SQTS described in 2004. We present a case of Short QT syndrome in a 53 year old male. Case: A 53 year old male with a PMH of HTN, alcohol abuse, and tobacco dependence presented to the ED with palpitations. Patient endorsed that he was in his usual state of health the day prior to arrival. He went to bed after drinking alcohol and woke up suddenly pale and diaphoretic with dyspnea and a persistent feeling of impending doom. On arrival to the ED, he was tachypneic (26 breaths/min) with a heart rate of 163 bpm and a blood pressure of 100/80 mmHg. EKG showed atrial fibrillation with RVR. The patient converted to normal sinus rhythm after one dose of IV Cardizem 10 mg was administered for rate control. The next day he had multiple episodes of Torsades de Pointe and monomorphic ventricular tachycardia treated with synchronized cardioversion, 2g of magnesium, IV amiodarone and lidocaine drip. He was transferred to the ICU for further evaluation and monitoring. Repeat EKG showed normal sinus rhythm at 75 bpm and short QT (QT= 328). TTE showed normal biventricular size and function (LVEF 60-65%) with no valvular abnormalities. Dual chamber Implantable Cardioverter Defibrillator (ICD) was placed and outpatient genetic testing was scheduled. Discussion: SQTS is very rare with roughly 70 cases identified worldwide since the condition was discovered in 2000. It is a congenital channelopathy related to potassium channels and represented by a normal heart rate with accelerated cardiac repolarization. Normal QT range is 350-440 msec while SQTS range is 210-340 msec. Mutations in the KCNH2, KCNJ2, or KCNQ1 genes lead to enhanced flow of potassium ions across the membrane of cardiac muscle cells. Patients can present at any age with palpitations, syncope, atrial fibrillation, and sudden cardiac death. The cornerstone to diagnosing SQTS is an electrocardiogram. Patients with SQTS can be managed with ICD implantation, quinidine (especially with KCNH2 mutation), and sotalol (with other mutations other than KCNH2).


2015 ◽  
Vol 308 (2) ◽  
pp. H126-H134 ◽  
Author(s):  
Erin Harleton ◽  
Alessandra Besana ◽  
Parag Chandra ◽  
Peter Danilo ◽  
Tove S. Rosen ◽  
...  

Atrial fibrillation (AF) is a common arrhythmia with significant morbidities and only partially adequate therapeutic options. AF is associated with atrial remodeling processes, including changes in the expression and function of ion channels and signaling pathways. TWIK protein-related acid-sensitive K+ channel (TASK)-1, a two-pore domain K+ channel, has been shown to contribute to action potential repolarization as well as to the maintenance of resting membrane potential in isolated myocytes, and TASK-1 inhibition has been associated with the induction of perioperative AF. However, the role of TASK-1 in chronic AF is unknown. The present study investigated the function, expression, and phosphorylation of TASK-1 in chronic AF in atrial tissue from chronically paced canines and in human subjects. TASK-1 current was present in atrial myocytes isolated from human and canine hearts in normal sinus rhythm but was absent in myocytes from humans with AF and in canines after the induction of AF by chronic tachypacing. The addition of phosphatase to the patch pipette rescued TASK-1 current from myocytes isolated from AF hearts, indicating that the change in current is phosphorylation dependent. Western blot analysis showed that total TASK-1 protein levels either did not change or increased slightly in AF, despite the absence of current. In studies of perioperative AF, we have shown that phosphorylation of TASK-1 at Thr383 inhibits the channel. However, phosphorylation at this site was unchanged in atrial tissue from humans with AF or in canines with chronic pacing-induced AF. We conclude that phosphorylation-dependent inhibition of TASK-1 is associated with AF, but the phosphorylation site responsible for this inhibition remains to be identified.


Circulation ◽  
2014 ◽  
Vol 130 (suppl_2) ◽  
Author(s):  
Chingping Wan ◽  
Steven J Szymkiewicz

Introduction: The wearable cardioverter defibrillator (WCD) has been used to protect AMI patients with reduced LVEF (≤35%) until ICD evaluation is recommended. The rate of EF improvement (e.g. EF>35%) over the initial 8-12 weeks after AMI has not been reported. METHODS: The manufacturer-maintained registry was searched for AMI patients who received a WCD shock for VT/VF between 05/2008 and 02/2013. The treated group was matched (1: ~4) with event-free WCD patients by ICD-9 code (410.*), gender, age and prescription date. Chart notes were reviewed for clinical characteristics. Follow-up was assessed through the registry and Social Security Death Master File. RESULTS: There were 992 (age=63±12, female=20.2%) AMI patients included in the final analysis, 206 treated by WCD and 786 event-free patients. Median follow-up was 334 days. Mean length of WCD use was 67±506 (median=38) days. Subgroup clinical characteristics are presented in Table 1. In the event-free group, 289 (38.9%) patients showed EF improvement to >35%. Nine (4.5%) in the treated group continued wearing the WCD until EF recovery, while 125 (60.7%) received ICD. Absence of recorded heart failure and/or diabetes were associated with LVEF recovery (p<.0001). CONCLUSION: In our study, almost 40% of AMI patients with initial EF ≤35% had EF improvement in two months. The EF recovery group had lower rates of heart failure and diabetes. WCD allows time for left ventricular function recovery in low EF post MI patients, optimizing ICD implantation decisions.


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