Hyperkalemia Induced T Wave Oversensing Leading to Loss of Biventricular Pacing and Inappropriate ICD Shocks

Koul, Ashok K.; Keller, Stuart; Clancy, Jude; Lampert, Rachel; Batsford, William P.; Rosenfeld, Lynda E.

doi:10.1111/j.1540-8159.2004.00509.x

Cited by 39 publications

(30 citation statements)

References 6 publications

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“…T-wave oversensing with large R waves is caused by an absolute increase in T-wave amplitude. Clinical correlates include pediatric patients, 22,23 hypertrophic cardiomyopathy, 24 long QT syndrome, 25,26 short QT syndrome, 27,28 hyperkalemia, 29 and, rarely, other drug and metabolic abnormalities. 30,31 In contrast, in the setting of small R waves, oversensed T waves usually have normal amplitude, such as in Brugada Syndrome 32,33 or advanced myocardial disease.…”

Section: T-wave Oversensing: Clinical Aspectsmentioning

confidence: 99%

Troubleshooting Implanted Cardioverter Defibrillator Sensing Problems I

Swerdlow

Asirvatham

Ellenbogen

et al. 2014

Circ: Arrhythmia and Electrophysiology

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electrograms from floating bipolar atrial electrodes on defibrillation leads. 12,13 The former requires a dual-coil lead and the latter a specialized lead. Evaluating Sensing From ICD ElectrogramsFilter settings may influence electrogram appearance (Figure 2). Wideband signals with minimal filtering reproduce QRS complexes accurately and retain the distinctive, rounded appearance of T waves. Highly filtered narrowband signals display the signal that is compared with the sensing threshold in the sensing process, but they alter signal amplitude and polarity, markedly reducing the amplitude of signals with prominent low-frequency components, such as T waves and some components of VF ( Figure I in the Data Supplement). Programmable filter settings (St. Jude Medical and Biotronik) permit assessing the effect of filtering on R-and T-wave amplitude.Sampling is the process of converting an analog signal into a digital sequence. It must be performed at ≥2× the source's signal frequency to reproduce the source's information content completely. ICD telemetry reproduces cardiac signals completely because it samples at 128 to 256 Hz per channel, but it may distort nonphysiological signals periodically (Figure II in the Data Supplement) 14 and it may not completely reproduce myopotentials that have frequency content >100 Hz. Stored Versus Real-Time ElectrogramsStored electrograms and their corresponding interval and episode data are the primary sources for diagnosing devicedetected tachycardias. Real-time electrograms are useful in troubleshooting reproducible oversensing: lead or connector problems in the pocket may be identified by pocket manipulation, pectoral or diaphragmatic myopotentials can be provoked by pectoral muscle contraction and straining or deep breathing, respectively (Figure III in the Data Supplement). Differential electrograms recorded simultaneously between 1 common electrode and 2 different electrodes are useful when lead or connector-related oversensing is suspected (Figure 3). Role of Additional Diagnostics, Alerts, and Remote MonitoringTrend plots of P-and R-wave amplitude, impedance measurements and trends, and algorithms that identify oversensing facilitate electrogram interpretation as discussed below. Alerts for suspected oversensing may notify the patient using audible tones or pulse generator vibration, may be transmitted via internet-based remote-monitoring networks, or both. Remote monitoring has transformed follow-up of sensing problems, permitting rapid determination of cause of an alert and implementation of a response plan, especially for devices with wireless telemetry.16,17 Troubleshooting Ventricular OversensingPresentation, Classification, and Recognition Clinical PresentationIn ICD patients, ventricular oversensing of rapid signals presents as oversensing alerts or inappropriate detection of VT/ VF, often resulting in inappropriate shocks. In pacemakerdependent patients it also presents as failure to deliver bradycardia pacing. ClassificationOversensing can be classified by electro...

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Section: T-wave Oversensing: Clinical Aspectsmentioning

confidence: 99%

Troubleshooting Implanted Cardioverter Defibrillator Sensing Problems I

Swerdlow

Asirvatham

Ellenbogen

et al. 2014

Circ: Arrhythmia and Electrophysiology

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“…While the intracardiac R and T waves remained stable during follow-up, the peak-topeak T wave amplitude at the time of admission had increased to 4.5 mV, and its slope was steeper (Fig. 3) (3,4). In the present patient, hyperkalemia was apparently induced by the combined effects of medications and dehydration during a minor illness.…”

Section: Case Reportmentioning

confidence: 48%

Correlation between Surface and Intracardiac Electrocardiogram in a Patient with Inappropriate Defibrillation Shocks Due to Hyperkalemia

et al. 2009

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“…Hyperkalemia-induced oversensing by ICDs has previously been reported (1,2). In both of these cases, hyperkalemia (6.7 mM and 6.1 mM, respectively) resulted in T wave oversensing, observed during paced rhythm in the first patient (1) and sinus rhythm in the second (2), with the latter patient receiving inappropriate therapy.…”

Section: Discussionmentioning

confidence: 98%

A case of appropriate inappropriate device therapy: Hyperkalemia-induced ventricular oversensing

Oudit

Cameron

Harris

2008

Canadian Journal of Cardiology

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A 56-year-old woman with a history of congenital heart disease, type 2 diabetes mellitus and heart failure received inappropriate, but potentially life-saving, therapy from her implantable cardioverter defibrillator (ICD). At five years of age, she underwent surgical repair of a sinus venosus atrial septal defect with redirection of the pulmonary veins. As an adult, an ICD was subsequently implanted for a history of syncope and sustained ventricular tachycardia in the setting of left ventricular dysfunction. A coronary angiogram during her index admission revealed normal coronary artery anatomy. Her clinical course was also complicated by the development of atrial flutter with poorly controlled ventricular response rates, requiring atrioventricular nodal ablation. Thereafter, she was pacemaker-dependent, with no evident escape rhythm. In February 2005, she received seven appropriate device therapies for polymorphic ventricular tachycardia in the setting of hypokalemia (plasma potassium concentration ([K + ])=2.1 mM) and a prolonged QT interval. Given this history of hypokalemia and torsade de pointes requiring therapy, she was maintained on oral potassium supplementation.She was readmitted to hospital in April 2006 with pleuritic chest pain, hypotension and leukocytosis. Her baseline 12-lead electrocardiogram (ECG) confirmed a ventricular paced rhythm of 80 beats/min ( Figure 1A). Her baseline plasma [K + ] was 4.1 mM and magnesium concentration was 0.89 mM on admission. Her medications on admission included furosemide, metolazone, acetylsalicylic acid, warfarin, candesartan, spironolactone, amiodarone, metformin, pantoprazole, and magnesium and potassium supplementation. Over the ensuing 24 h, it became apparent that she was septic. In association with this, she became progressively hypotensive, and her serum creatinine increased from a baseline value of 134 μM to 265 μM, in association with oliguria. Telemetry analysis revealed gradual widening of the paced QRS complex, T wave changes, delay in the pacing artifact to ventricular activation time ( Figure 1B) and, ultimately, intermittent loss of ventricular capture (Figure 2A). This was followed by the development of a slow sinusoidal ventricular tachycardia, at a rate of 100 beats/min to 125 beats/min (610 ms to 480 ms) ( Figure 2B), which was terminated by the delivery of device therapy. This tachycardia was below the programmed detection rate of the device, which was programmed to deliver defibrillation therapy for rates of or greater than 176 beats/min (340 ms). Interrogation of the ICD logs revealed fractionation of the intracardiac electrogram ( Figure 3A), coupled with T wave oversensing ( Figure 3B) during the slow ventricular tachycardia, resulting in ventricular oversensing and the delivery of inappropriate, but life-saving, therapy. Interrogation of the ICD revealed a total of six episodes of ventricular arrhythmia detected by the device, which occurred over a 13 min period (Table 1). Three of the detected tachyarrhythmias that resulted in delivered ...

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Hyperkalemia Induced T Wave Oversensing Leading to Loss of Biventricular Pacing and Inappropriate ICD Shocks

Cited by 39 publications

References 6 publications

Troubleshooting Implanted Cardioverter Defibrillator Sensing Problems I

Troubleshooting Implanted Cardioverter Defibrillator Sensing Problems I

Correlation between Surface and Intracardiac Electrocardiogram in a Patient with Inappropriate Defibrillation Shocks Due to Hyperkalemia

A case of appropriate inappropriate device therapy: Hyperkalemia-induced ventricular oversensing

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