scholarly journals Inappropriate shock caused by P, and T wave oversensing in a subcutaneous Implantable Cardiac Defibrillator in a patient in sinus rhythm

2020 ◽  
Author(s):  
Alexander R. Ochman ◽  
Matthew Riesbeck ◽  
Raffaele Corbisiero
Keyword(s):  
Sinus Rhythm ◽  
Implantable Cardiac Defibrillator ◽  
Inappropriate Shock ◽  
T Wave

Thinking about the future – data on adolescent patients with a subcutaneous ICD

2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
K Willy ◽  
F Reinke ◽  
B Rath ◽  
N Boegeholz ◽  
J Wolfes ◽  
...  
Keyword(s):  
Sudden Cardiac Death ◽  
Children And Adolescents ◽  
Cardiac Death ◽  
Inappropriate Therapy ◽  
Single Center ◽  
Inappropriate Shock ◽  
Shock Delivery ◽  
T Wave

Abstract Background Implantable cardioverter-defibrillator (ICD) systems are established for the prevention of sudden cardiac death. Long-term data on ICD function in children and adolescents is rare and has suggested higher rates of lead failure as well as oversensing, both leading to inappropriate therapy. The present study displays a long-term single-center follow-up of young patients having received an S-ICD. Methods and results The present study represents a single-center experience of patients younger than 25 years who received an S-ICD (n=49). Follow-up data included regular in-house follow-up as well as unscheduled hospitalisations in our center. Mean age at implantation was 19.2±4.1 years and 33 patients (67.4%) were male. In 21 patients (42.9%) electrical heart disease or idiopathic ventricular fibrillation represented the underlying condition of ICD implantation. 15 patients suffered from HCM (30.6%). Median follow-up duration was 2 years. No patient died during the observation period. Appropriate shocks occurred in 7 patients (14.3%). Inappropriate shock delivery was recorded in 6 patients (12.3%). T-wave oversensing was the main cause for inappropriate shock delivery (5/6 patients), in the other patient myopotentials were the reason for inappropriate therapy. In one patient, operative refixation of the subcutaneous lead was necessary due to hypermobility leading to oversensing. After modification of the sensing vector as well as activation of the SMART pass filter no further oversensing episodes occurred in any patient. Conclusion ICD therapy in children and adolescents is effective for prevention of sudden cardiac death. Every episode was terminated by the first therapy. The rate of appropriate shock as well as inappropriate therapies was quite high compared to typical ICD cohorts. In particular T-wave oversensing seems to be challenging for the S-ICD detection algorithms also in this cohort. Funding Acknowledgement Type of funding source: None

P1480French experience of SICD implantation

EP Europace ◽  
2020 ◽  
Vol 22 (Supplement_1) ◽  
Author(s):  
J Proukhnitzky ◽  
N Badenco ◽  
E Gandjbakhch ◽  
C Maupain ◽  
X Waintraub ◽  
...  
Keyword(s):  
Procedure Time ◽  
Inappropriate Shock ◽  
Subcutaneous Icd ◽  
T Wave ◽  
Kaplan Meier ◽  
French Experience ◽  
Shock Impedance ◽  
Appropriate Shocks ◽  
Implantation Success

Abstract OnBehalf GPUR Introduction The subcutaneous ICD prevents complications of transvenous leads. Its implantation needs a defibrillation test. Performing this test increases the time of procedures.. Purpose The aim of our study is to describe the experience of subcutaneous ICD of Assitance Publique des Hopitaux de Paris (AP-HP). Materials and Methods In a retrospective cohort we included patients who were involved in subcutaneous ICD treatment at the 5 hospitals of AP-HP from December 2012 to April 2018.Analysis used the Kaplan-Meier method and the Mann-Whitney U test. Results 162 patients were implanted. 76% of implantations were for secondary prevention before 2017, but only 49% after 2017. 126 (77%) tests were successful at first shock, 14 (8.6%) needed a second shock or more, 9 (5.5%) did not have a test. The shock impedance was significantly higher when the shock was not effective at the first test, 82 ohms CI 95% [68; 112] versus 66 ohms CI 95% [64; 70], p <0.05. 6 patients died (3.7%). Late follow up showed 23 (10%) appropriate shocks and 24 inappropriate shocks (11%) mainly due to T wave oversensing (37.5%). Conclusions This is the first french experience of SICD implantation. Success of defibrillation test was lower than expected. Caracteristics of implantation General anesthesia (%) 162 (100) Procedure time (min) Mean ± SD (median)Range 73± 24 (60)20-165 Cameron Health (%) Generator SQ-RX ® 1010 12 (7.4) Boston Scientific (%) Generator EMBLEM ® A209 100 (61.7) Generator EMBLEM ® A219 44 (27.2) VF time (sec) Mean ± SD (median)Range 16.5± 3.4(15)10-37 Shock Impedance (ohm) Mean ± SD (median) Range 72 ± 12.7 (68) 42-130 Success at 1st shock (%) 126 (77.7) Success at 2nd shock or more (%) 14 (8.6) No test performed (%) 12 (7.4) Implantation caracteristics and defibrillation testing. Impedance was significantly higher in patients without success at first shock : 82 ohms CI 95% [68 ;112] vs 66 ohms CI 95% [64 ;70], p < 0.05. Abstract Figure. Survival without inappropriate shock

Using Left-Ventricular–Only Pacing to Eliminate T-Wave Oversensing in a Biventricular Implantable Cardiac Defibrillator

2013 ◽  
Vol 29 (2) ◽  
pp. 254.e5-254.e7 ◽  
Author(s):  
Clarence Khoo ◽  
Matthew Bennett ◽  
Santabhanu Chakrabarti ◽  
John LeMaitre ◽  
Stanley K.K. Tung
Keyword(s):  
Left Ventricular ◽  
Implantable Cardiac Defibrillator ◽  
T Wave

RECURRENT VENTRICULAR TACHYCARDIA IN AN INFANT—USE OF HIGH VOLTAGE DC SHOCK THERAPY IN MANAGEMENT

PEDIATRICS ◽  
1964 ◽  
Vol 33 (6) ◽  
pp. 926-930
Author(s):  
Ramon V. Canent ◽  
Madison S. Spach ◽  
James J. Morris ◽  
Will L. London
Keyword(s):  
Ventricular Tachycardia ◽  
Drug Therapy ◽  
Sinus Rhythm ◽  
Cardiac Cycle ◽  
Normal Sinus Rhythm ◽  
Shock Therapy ◽  
Right Atrial ◽  
Qrs Complex ◽  
T Wave ◽  
Normal Sinus

The case of a 17-month-old infant with ventricular tachycardia has been presented. The diagnosis was confirmed by esophageal and right atrial electrocardiography. No cardiac abnormalities were demonstrated by bilane angiocardiography. Quinidine and steroid therapy were effective temporarily for conversion to normal sinus rhythm. Gradually, conversion became more difficult and sustained ventricular tachycardia became refractory to drug therapy. A Lown Cardioverter was employed with a single countershock discharge of 8 to 15 watt seconds (1,000 to 1,370 volts). The shock was electronically timed to occur at the peak of the QRS complex to avoid the vulnerable period of the cardiac cycle (T-wave), wherein the shock may initiate ventricular fibrillation. Normal sinus rhythm was established on five occasions with the administration of a single shock. Following this therapy, the patient remained well and maintained a normal sinus rhythm for ten months while on Quinaglute duratabs® and reserpine.

scholarly journals Electrocardiogram in Bitches Submitted to Unilateral Total Mastectomy

2019 ◽  
Vol 47 (1) ◽  
Author(s):  
Karen Suzane Fuchs ◽  
Helena Mondardo Cardoso ◽  
Ronise Tochetto ◽  
Felipe Comassetto ◽  
Luara Da Rosa ◽  
...  
Keyword(s):  
Sinus Rhythm ◽  
Respiratory Sinus Arrhythmia ◽  
Qt Interval ◽  
Companion Animals ◽  
Mammary Tumors ◽  
Paraneoplastic Syndromes ◽  
Sinus Arrhythmia ◽  
T Wave ◽  
Oncological Diseases ◽  
Electrocardiographic Changes

Background: The frequency of oncological diseases in companion animals has increased in recent years, mainly due to the longer longevity of dogs. The neoplasms are not only open by the presence of the tumor and its location, but also by paraneoplastic syndromes, which are disorders that occur due to the production of substances by the tumor that cause. In addition to causing local changes and damages, oncological diseases may also result in injuries at distant sites, such as paraneoplastic syndromes, which, if untreated, may result in death of animals. The present study aimed to investigate whether female dogs with mammary tumors demonstrate electrocardiographic changes, and if so, to investigate whether these cease after removal of the tumor, and to relate the type of tumor with the occurrence of arrhythmias. Materials, Methods & Results: Eighteen female dogs, aged between 4 and 14 years, underwent electrocardiogram 24 h prior to undergoing a total unilateral mastectomy. After removal of the tumor, electrocardiograms were again performed 24 (M24), 48 (M48), and 72 (M72), as well as 14 days (M14d) after surgery. Histological analysis of the neoplasms showed that 55% of the tumors were benign, with predominance of adenoma (38%), and 45% were malignant, with predominance of adenocarcinoma (22%). The following rhythms and arrhythmias were observed: normal sinus rhythm (37.2%), sinus arrhythmia (62.8%), wandering pacemaker (26%), 1st degree atrioventricular block (AVB; 5%), premature ventricular complex (PVC; 10%), and T-wave > 25% of R-wave (25%); more than one change could occur simultaneously. Out of the evaluated electrocardiographic parameters, a significant difference was observed in the QT interval between the following timepoints: M24 (204 ± 18), M48 (204 ± 22), and M72 (203 ± 23), as well as Mbasal (192 ± 15) and M14d (178 ± 43).Discussion: Regarding the observed rhythms, arrhythmias, and changes, respiratory sinus arrhythmia was the normal predominant rhythm, followed by sinus rhythm. Wandering pacemaker in conjunction with respiratory sinus arrhythmia is widely observed in dogs; these conditions occur due to vagal predominance, without hemodynamic consequences. PVC is the premature depolarization originating in ectopic foci of the ventricular tissue, and is considered the most common type of ventricular arrhythmia in small animals. Two animals demonstrated PVC, one in Mbasal and the other in M14d. The former presented with a tumor diagnosed as an adenocarcinoma, which could be related to the paraneoplastic syndrome. The later presented with a tumor diagnosed as an adenoma, indicating that PVC may have occurred due to stress at that time. The T-wave occurs after ventricular depolarization, and is usually up to 25% of the amplitude of the R-wave. This change was observed at all times for the animal that was histologically diagnosed as having mammary adenocarcinoma, and may have been related to the neoplasm or be an individual change. The 1st degree AVB occurred in Mbasal, and was therefore related to increased vagal tonus. The significant differences in the QT interval were negatively correlated with decreased heart rate (HR), i.e., the QT interval increased when HR decreased. This must have been related to the acclimatization of the animals to the tests. Owing to the high number of animals with early-stage mammary tumors in this study, the observed electrocardiographic changes could not be correlated with tumor presence and type.

scholarly journals Incidence, mechanisms, and clinical impact of inappropriate shocks in patients with a subcutaneous defibrillator

EP Europace ◽  
2020 ◽  
Vol 22 (5) ◽  
pp. 761-768
Author(s):  
Boris Rudic ◽  
Erol Tülümen ◽  
Fabian Fastenrath ◽  
Susanne Röger ◽  
Diana Goranova ◽  
...  
Keyword(s):  
First Generation ◽  
Automatic Gain Control ◽  
Gain Control ◽  
Primary And Secondary Prevention ◽  
Inappropriate Shock ◽  
Subcutaneous Defibrillator ◽  
Inappropriate Shocks ◽  
T Wave ◽  
Primary Vector

Abstract Aims Inappropriate shocks (IAS) remain a challenge for patients and physicians after implantation of the subcutaneous implantable cardioverter-defibrillator (S-ICD). The aims were to assess and characterize different patterns of IAS. Methods and results Two hundred and thirty-nine patients were implanted with an S-ICD between 2010 and 2018 for primary and secondary prevention. Follow-up data of at least 6 months were analysed. During a mean follow-up of 34.9 ± 16.0 months, a total of 73 shocks occurred in 38 patients (6%). Forty-three (59%) shocks were considered appropriate due to ventricular tachycardia/ventricular fibrillation, while 30 (41%) were inappropriate and occurred in 19 patients (8%). Myopotentials/noise was the most frequent cause of inappropriate shocks (n = 8), followed by T-wave oversensing (n = 6) and undersensing of the QRS, resulting in adaptation of the automatic gain control and inappropriate shock (n = 5). Seventy-four percent of all IAS occurred on the primary vector, while no IAS occurred on the alternate vector. In seven of eight patients (88%), IAS related to myopotentials have occurred on the primary sensing vector. Multivariate analysis identified taller patients, primary sensing vector and first-generation S-ICD device as predictors for IAS. SMART pass effectively reduced the occurrence of IAS in the second-generation S-ICD system. Conclusion Inappropriate therapies are less frequently observed on the alternate vector. The primary vector seems to be unfavourable with regard to oversensing caused by myopotentials. Inappropriate shocks were associated with an increased rate of rehospitalization but not mortality. These observations have implications for the prevention of inappropriate S-ICD shocks.

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