A case of withheld defibrillator treatment for 9 minutes of ventricular tachycardia (original) (raw)
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Pacing and Clinical Electrophysiology, 2013
inappropriate implantable cardioverter-defibrillator therapy, atrioventicular nodal re-entry tachycardia, supraventricular tachycardia Case Presentation A 71-year-old man with a dilated cardiomyopathy (left ventricular ejection fraction [LVEF] < 20%) received a biventricular implantable cardioverter-defibrillator (ICD) (Boston Scientific Cognis 100-D N107, Boston Scientific, Natick, MA, USA) for primary prevention and symptomatic heart failure with left bundle branch block. His right ventricular (RV) ICD lead was implanted in the RV apex, the right atrial (RA) lead in the RA appendage, and the left ventricular lead in a lateral coronary sinus branch. He presented to the emergency room following an episode of palpitations and an ICD shock from his device 6 months postimplant. The implant settings of his ICD were as follows: ventricular fibrillation zone ≥ 240 beats/min (≤250 ms), ventricular tachycardia (VT) zone ≥ 185 beats/min (≤324 ms). VT therapy was programmed as "scan" with three bursts of 10 pulses followed by ICD shocks. Detection enhancements (Rhythm ID) was turned "on" with the sustained rate duration set at 3 minutes. The atrial fibrillation rate threshold was programmed at 170 beats/min with stability at 20 ms. Interrogation of his ICD revealed two tachycardia episodes. Three bursts of antitachycardia pacing (ATP) were unsuccessful in terminating the first tachycardia episode, which progressed to a successful ICD shock. The first burst of ATP of the second tachycardia episode is shown (Figure 1). Three ICD electrogram channels are recorded We declare we have no conflicts of interest.
Failure of an Implantable Cardioverter Defibrillator to Terminate Ventricular Tachycardia: Why?
Pacing and Clinical Electrophysiology, 2010
A 69-year-old man with a history of coronary artery bypass grafting for severe three-vessel coronary artery disease underwent the implantation of a cardioverter defibrillator with cardiac resynchronization (CRT-D) for reduced left ventricular ejection fraction (LVEF) (EF 25%) associated with clinical signs of heart failure (New York Heart Association class III) in December 2005. A three-chamber implantable cardioverter defibrillator (ICD) (Insync Sentry 7298, Medtronic Inc., Minneapolis, MN, USA) was implanted and the improvement of heart failure occurred during the following months despite the development of permanent atrial fibrillation in October 2006. The device was programmed with a ventricular tachycardia (VT) zone of 171-188 beats/min (350-320 ms) and a ventricular fibrillation (VF) zone of 188-500 beats/min (320-120 ms). The counter for VT detection was set at 16 intervals and for VF at 12/16. In the VT zone, the programmed therapy consisted in two antitachycardia pacing protocols (burst and ramp +; three sequences each) followed by cardioversion with 35 J. In the VF zone, therapy consisted of defibrillation at 35 J. Criteria for supraventricular tachycardia discrimination were activated because of persistent atrial fibrillation; pacing mode was VVIR 70-120 beats/min; sequential biventricular pacing was programmed with left ventricular preexcitation of 20 ms. The patient was not taking any antiarryhthmic medication except for β-blockers.
An Appropriate Implantable Cardioverter-Defibrillator Shock Triggering Unusual Phenomenons
Pacing and Clinical Electrophysiology, 2010
CRT, Defibrillation-ICD Case Presentation A 57-year-old man with ischemic cardiomyopathy and a history of ventricular tachycardia (VT) 1 was admitted to the hospital after experiencing two consecutive implantable cardioverterdefibrillator (ICD) shocks. The patient had undergone placement of a biventricular pacemaker and defibrillator (Atlas TM +HF V-341, St. Jude Medical, Minneapolis, MN, USA) 18 months prior to admission. After implantation, the patient experienced frequent episodes of VT requiring ICD firing, and his medical therapy was optimized. However, episodes of VT continued to occur; these episodes were underdetected by the ICD due to the slow rate of VT (120 beats per minute [bpm]) resulting from the use of antiarrhythmic drugs. 2 During one clinic visit, the use of specific antitachycardia pacing (ATP) schemes resulted in the successful termination of VT; nonetheless, ablation of the clinical tachycardia was still attempted. Programmed electrical stimulation failed to induce clinical VT, but it induced up to six nonclinical, hemodynamically unstable VT morphologies. A substrate ablation procedure was performed and treatment with sotalol was then initiated. The device was reprogrammed with the slow VT detection zone starting at 110 bpm. On admission, a summary of programmed parameters included the following: pacing mode DDDR, base rate 60 bpm, max track rate 90 bpm (limited by slow VT detection zone programmed at 110 bpm), atrial sensitivity 0.6 mV, ventricular sensitivity automatic (maximum 0.3 mV), and ventricular sense refractory period 125 ms. P-and Conflict of Interest: None.
Catastrophic implantable cardioverter-defibrillator misclassification of ventricular tachycardia
European journal of case reports in internal medicine, 2024
Inappropriate therapy is a frequent adverse consequence of implantable cardioverter-defibrillator. Inappropriate therapy often occurs due to the misinterpretation of sinus tachycardia or atrial fibrillation/flutter with rapid atrioventricular conduction by the device. Current implantable cardioverter-defibrillator (ICD) mechanisms integrate various discriminators into algorithms to differentiate supraventricular tachycardia (SVT) from ventricular tachycardia (VT), to prevent such occurrences. A 40-year-old man suffered seizures and cardiac arrest abruptly, without prior complaints of chest pain. Without delay, he initiated cardiopulmonary resuscitation (CPR), resulting in the regaining of spontaneous circulation. The patient had previously received a single-chamber ICD due to recurring VT and a prior episode of cardiac arrest. The patient had a medical background of coronary artery disease with complete revascularisation and no previous occurrence of SVT. Interrogating the ICD revealed captured non-sustained ventricular tachycardia (NSVT) and SVT events but no VT episode or shock therapy. During the specified time period, the patient underwent an electrophysiological study, and no SVT was induced with the normal function of the atrioventricular and sinoatrial nodes. Various causes can lead to errors in morphology discrimination criteria in single-chamber ICDs. Extending the detection interval is highly recommended to avoid misclassification of ICDs.
Journal of the American College of Cardiology, 2000
This retrospective study was performed to provide data on ventricular tachycardias (VT) with a cycle length longer than the initially programmed tachycardia detection interval (TDI) in patients with implantable cardioverter defibrillators (ICDs). BACKGROUND It has been clinical practice to program a safety margin of 30 to 60 ms between the slowest spontaneous or inducible VT and the TDI. METHODS Baseline characteristics of 659 consecutive patients with ICDs were prospectively; follow-up information was retrospectively collected. RESULTS During a mean follow-up of 31 Ϯ 23 months, 377 patients (57.2%) had at least one recurrent VT or ventricular fibrillation; 47 patients (7.1%) suffered 61 VTs above the TDI. The risk of a VT above the TDI ranged between 2.7% and 3.5% per year during the first four years after ICD implantation. The difference between the cycle length of the slowest VT before ICD implantation, spontaneous or induced, and the first VT above TDI was 108 Ϯ 58 ms. Fifty-four VTs (88.5%) above the TDI were associated with significant clinical symptoms (angina or palpitation 63.9%, heart failure 6.6% and syncope 8.2%). Six patients (9.8%) had to be resuscitated. Kaplan-Meyer analysis identified New York Heart Association class II or III (p ϭ 0.021), ejection fraction Ͻ 0.40 (p ϭ 0.027), spontaneous (p Ͻ 0.001) or inducible (p Ͻ 0.001) monomorphic VTs and the use of class III antiarrhythmic drugs (amiodarone, p Ͻ 0.001; sotalol, p ϭ 0.004) as risk predictors of VTs above the TDI. The risk of recurrent VTs above TDI was 11.8%, 12.5% and 26.6% during the first, second and third year after first VT above TDI, respectively. CONCLUSIONS The risk of VTs above the TDI is significantly increased in some patients, and many VTs above TDI cause significant clinical symptoms. A larger safety margin between spontaneous or inducible VTs and the TDI seems to be necessary in selected patients. This is in conflict with an increased risk of inadequate episodes and demands highly specific and sensitive detection algorithms in these patients.
Circulation, 2001
for the AVID Investigators Background-Sustained ventricular tachycardia (VT) can be unstable, can be associated with serious symptoms, or can be stable and relatively free of symptoms. Patients with unstable VT are at high risk for sudden death and are best treated with an implantable defibrillator. The prognosis of patients with stable VT is controversial, and it is unknown whether implantable cardioverter-defibrillator therapy is beneficial. Methods and Results-Screening for the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial identified patients with both stable and unstable VT. Both groups were included in a registry, and their clinical characteristics and discharge treatments were recorded. Mortality data were obtained through the National Death Index. The mortality in 440 patients with stable VT tended to be greater than that observed in 1029 patients presenting with unstable VT (33.6% versus 27.6% at 3 years; relative risk [RR]ϭ1.22; Pϭ0.07). After adjustment for baseline and treatment differences, the RR was little changed (RRϭ1.25, Pϭ0.06). Conclusions-Sustained VT without serious symptoms or hemodynamic compromise is associated with a high mortality rate and may be a marker for a substrate capable of producing a more malignant arrhythmia. Implantable cardioverter-defibrillator therapy may be indicated in patients presenting with stable VT. (Circulation. 2001;103: 244-252.)