RESUMEN
OBJECTIVE. An important application of late gadolinium enhancement (LGE) cardiac MRI is accurate assessment of myocardial scar before ablation. However, this is often limited in patients with cardiac implantable electronic devices (CIEDs) because of metal device-induced artifacts. The purpose of this study was to determine whether a modified wideband inversion recovery (IR) LGE MRI technique decreases artifact volume to allow the assessment of myocardial scar. SUBJECTS AND METHODS. Fifty patients (17 women and 33 men; mean age ± SD, 61 ± 12 years; mean ejection fraction ± SD, 35.9% ± 13.3%) with CIEDs underwent cardiac MRI using conventional and modified wideband IR LGE techniques before ablation. The volume of device-induced artifact was quantified and stratified by tertiles on mild, moderate, and severe. Ordinal logistic regression analysis assessed the association between artifact volume on conventional and wideband images adjusted for patients' demographics. RESULTS. Conventional LGE MRI resulted in device-induced hyperintense artifacts that obscured ventricular segments in 32 of 50 (64%) cases. Wideband LGE MRI significantly reduced severe artifact volume (p < 0.0001) and completely resolved all mild and most moderate artifacts. Overall, wideband techniques resulted in a 56% reduction in total artifact volume for the cohort (p < 0.0001). The wideband LGE MRI sequence minimized artifacts in the most commonly obscured segments on the conventional LGE MRI sequence, with persistent artifacts in seven, eight, and four of 32 cases at the basal anterior, midventricular anterior, and midventricular anteroseptal segments, respectively. CONCLUSION. The modified wideband IR technique completely resolves mild and moderate device-induced hyperintense artifacts and significantly reduces the volume of severe artifact to allow accurate identification of myocardial scar in patients with CIEDs before ablation.
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Artefactos , Cicatriz/diagnóstico por imagen , Desfibriladores Implantables , Imagen por Resonancia Magnética/métodos , Miocardio/patología , Marcapaso Artificial , Medios de Contraste , Femenino , Humanos , Masculino , Metales , Persona de Mediana Edad , Estudios ProspectivosRESUMEN
AIMS: Magnetic resonance imaging (MRI) has been reported to be safe in patients with cardiac implantable electronic devices (CIED) provided a specific protocol is followed. The objective of this study was to assess whether this is also true for patients excluded from published protocols. METHODS AND RESULTS: A total of 160 MRIs were obtained in 142 consecutive patients with CIEDs [106 patients had an implantable cardioverter defibrillator (ICD) and 36 had a pacemaker implanted] using an adapted, pre-specified protocol. A cardiac MRI was performed in 95 patients, and a spinal/brain MRI was performed in 47 patients. Forty-six patients (32%) had either abandoned leads (n = 10), and/or were pacemaker dependent with an implanted ICD (n = 19), had recently implanted CIEDs (n = 1), and/or had a CIED device with battery depletion (n = 2), and/or a component of the CIED was recalled or on advisory (n = 32). No major complications occurred. Some device parameters changed slightly, but significantly, right after or at 1-week post-MRI without requiring any reprogramming. In one patient with an ICD on advisory, the pacing rate changed inexplicably during one of his two MRIs from 90 to 50 b.p.m. CONCLUSION: Using a pre-specified protocol, cardiac and non-cardiac MRIs were performed in CIED patients with pacemaker dependency, abandoned leads, or depleted batteries without occurrence of major adverse events. Patients with devices on advisory need to be monitored carefully during MRI, especially if they are pacemaker dependent.
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Quemaduras por Electricidad/etiología , Contraindicaciones , Desfibriladores Implantables/efectos adversos , Falla de Equipo/estadística & datos numéricos , Reacción a Cuerpo Extraño/etiología , Imagen por Resonancia Magnética/efectos adversos , Marcapaso Artificial/efectos adversos , Quemaduras por Electricidad/prevención & control , Femenino , Reacción a Cuerpo Extraño/prevención & control , Humanos , Masculino , Persona de Mediana Edad , Reproducibilidad de los Resultados , Sensibilidad y EspecificidadRESUMEN
A formal communication process was established and evaluated for the management of patients with cardiac implantable electronic devices (CIEDs) receiving radiation therapy (RT). Methods to estimate dose to the CIED were evaluated for their appropriateness in the management of these patients. A retrospective, institutional review board (IRB) approved study of 69 patients with CIEDs treated with RT between 2005 and 2011 was performed. The treatment sites, techniques, and the estimated doses to the CIEDs were analyzed and compared to estimates from published peripheral dose (PD) data and three treatment planning systems(TPSs) - UMPlan, Eclipse's AAA and Acuros algorithms. When measurements were indicated, radiation doses to the CIEDs ranged from 0.01-5.06 Gy. Total peripheral dose estimates based on publications differed from TLD measurements by an average of 0.94 Gy (0.05-4.49 Gy) and 0.51 Gy (0-2.74 Gy) for CIEDs within 2.5 cm and between 2.5 and 10 cm of the treatment field edge, respectively. Total peripheral dose estimates based on three TPSs differed from measurements by an average of 0.69 Gy (0.02-3.72 Gy) for CIEDs within 2.5 cm of the field edge. Of the 69 patients evaluated in this study, only two with defibrillators experienced a partial reset of their device during treatment. Based on this study, few CIED-related events were observed during RT. The only noted correlation with treatment parameters for these two events was beam energy, as both patients were treated with high-energy photon beams (16 MV). Differences in estimated and measured CIED doses were observed when using published PD data and TPS calculations. As such, we continue to follow conservative guidelines and measure CIED doses when the device is within 10 cm of the field or the estimated dose is greater than 2 Gy for pacemakers or 1 Gy for defibrillators.
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Desfibriladores Implantables , Marcapaso Artificial , Radioterapia de Intensidad Modulada/métodos , Neoplasias Torácicas/radioterapia , Algoritmos , Análisis de Falla de Equipo , Humanos , Fotones/uso terapéutico , Radiometría , Dosificación Radioterapéutica , Estudios RetrospectivosRESUMEN
OBJECTIVES: To determine whether risk for implantable cardioverter-defibrillator (ICD) therapy varies by body mass index (BMI) in systolic heart failure (HF). BACKGROUND: It is unknown whether obesity increases sudden death risk in patients with systolic HF. METHODS: Secondary analysis of patients with HF, left ventricular ejection fraction ≤0.40 and ICD (N = 464) was performed using Cox regression modeling to assess risk for first delivered ICD therapy, with patients grouped by BMI (kg/m(2)): normal (18.5 to <25), overweight (25 to <30), and obese (≥30). RESULTS: Overweight patients, compared with patients with normal BMI, had greater adjusted risk for first ICD therapy (HR 1.66; 95% CI 1.02-2.71; P = 0.04), whereas obese BMI was not associated with risk for first ICD therapy. CONCLUSIONS: There was an inverted U-shaped relationship between BMI and risk for first ICD therapy among systolic HF patients, with highest risk in overweight BMI.
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Índice de Masa Corporal , Desfibriladores Implantables , Insuficiencia Cardíaca Sistólica/complicaciones , Sobrepeso/complicaciones , Anciano , Muerte Súbita Cardíaca/etiología , Femenino , Humanos , Masculino , Persona de Mediana Edad , Modelos de Riesgos Proporcionales , Factores de Riesgo , Disfunción Ventricular Izquierda/complicacionesRESUMEN
BACKGROUND: Radiation therapy's (RT's) effects on cardiac implantable electronic devices (CIEDs) such as implantable cardioverter-defibrillators (ICDs) and pacemakers (PMs) are not well established, leading to device removal or relocation in preparation for RT. OBJECTIVE: To determine the effect of scattered RT on CIED performance. METHODS: We analyzed 69 patients--50 (72%) with PMs and 19 (28%) with ICDs--receiving RT at the University of Michigan. Collected data included device model, anatomic location, and treatment beam energies, treatment type, and estimated dose to the device. Patients were treated with either high-energy (16-MV) and/or low-energy (6 MV) photon beams with or without electron beams (6-16 MeV). The devices were interrogated with pre- and post-RT and/or weekly with either in-treatment or home interrogation, depending on the patient's dependence on the device and the estimated or measured delivered dose. Outcomes analyzed were inappropriate ICD therapies, device malfunctions, or device-related clinical events. RESULTS: The PMs were exposed to 84.4 ± 99.7 cGy of radiation, and the ICDs were exposed to 92.1 ± 72.6 cGy of radiation. Two patients with ICDs experienced a partial reset of the ICD with the loss of historic diagnostic data after receiving 123 and 4 cGy, respectively. No device malfunction or premature battery depletion was observed at 6-month follow-up from RT completion. CONCLUSIONS: CIED malfunction due to indirect RT exposure is uncommon. Regular in-treatment or home interrogation should be done to detect and treat these events and to ensure that diagnostic data are preserved.
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Arritmias Cardíacas/terapia , Desfibriladores Implantables , Análisis de Falla de Equipo/métodos , Neoplasias/radioterapia , Marcapaso Artificial , Radiación Ionizante , Anciano , Arritmias Cardíacas/complicaciones , Falla de Equipo , Femenino , Estudios de Seguimiento , Humanos , Masculino , Neoplasias/complicaciones , Dosificación Radioterapéutica , Estudios RetrospectivosRESUMEN
More patients who are receiving therapy with a left ventricular assist device (LVAD) also have an implantable cardioverter-defibrillator (ICD). The aim of the present study was to describe the outcomes and device interactions of simultaneous therapy with an ICD and a LVAD. We evaluated 76 patients with class IV heart failure (age 52 + or - 12 years, left ventricular ejection fraction 0.13 + or - 0.05%, 88% men, 61% nonischemic cardiomyopathy) with both an ICD and a LVAD. The median follow-up with both devices was 156 days. A LVAD with a pulsatile and continuous flow pump was used in 53 (70%) and 23 (30%) patients, respectively. Of the 76 patients, 12 (16%) received a total of 54 ICD therapies. Of the ICD therapies, 88% were appropriate. Of the 76 patients, 55 (72%) underwent heart transplantation a median of 146 days after LVAD implantation. Twelve patients (16%) died during simultaneous ICD and LVAD therapy. Interactions between the LVAD and ICD occurred in 2 patients (2.7%) with continuous flow pumps (HeartMate II). In both cases, telemetry failure occurred after LVAD implantation with 2 different models of ICDs from the same manufacturer. No ICD therapies occurred because of device-related interactions. In conclusion, simultaneous ICD and LVAD therapy in patients with severe congestive heart failure is safe and clinically feasible. Interactions between the devices are uncommon and appear limited to specific models of ICDs.
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Desfibriladores Implantables , Insuficiencia Cardíaca/terapia , Corazón Auxiliar , Adulto , Desfibriladores Implantables/efectos adversos , Diseño de Equipo , Falla de Equipo , Análisis de Falla de Equipo , Estudios de Factibilidad , Femenino , Estudios de Seguimiento , Insuficiencia Cardíaca/mortalidad , Insuficiencia Cardíaca/fisiopatología , Insuficiencia Cardíaca/cirugía , Trasplante de Corazón , Corazón Auxiliar/efectos adversos , Humanos , Masculino , Michigan/epidemiología , Persona de Mediana Edad , Calidad de Vida , Estudios Retrospectivos , Medición de Riesgo , Análisis de SupervivenciaRESUMEN
BACKGROUND: Tachycardia detection in first-generation biventricular pacemaker-implantable cardioverter defibrillators (BiV ICD) occurs through both the right ventricular (RV) and left ventricular (LV) leads, creating the potential for inappropriate detection and therapies. Little is known regarding the prevalence and management of patients with BiV ICDs and inappropriate detection. METHODS AND RESULTS: A transvenous, first-generation BiV ICD was implanted in 77 consecutive patients (age 61 +/- 11 years) for drug-refractory heart failure. The mean New York Heart Association class, QRS duration, and ejection fraction were 3.1 +/- 0.4, 168 +/- 24 ms, and 0.19 +/- 0.07, respectively. Among the 77 patients, 17 (22%) experienced inappropriate detection at a mean of 154 +/- 140 days after implantation. Fifteen of the 17 patients (88%) experienced inappropriate ICD therapy. In 16 of the 17 (94%) patients, the cause of inappropriate detection was double counting during sinus (8) or atrial rhythm (3), and nonsustained ventricular tachycardia (5). Despite reprogramming of the ICD, 9 patients (53%) required an additional procedure because of inappropriate therapies, including an upgrade to a dedicated BiV ICD (5), revision of the LV lead (2), ablation of the atrioventricular junction (1), and repeat defibrillation threshold testing (2). CONCLUSIONS: Inappropriate detection in patients with a first-generation BiV ICD is common and often results in inappropriate ICD therapy. The most common mechanism of inappropriate detection is double counting that often creates the need for additional procedures. Although devices in which tachycardia detection occurs only through the RV lead now are available, close follow-up of the many patients who received a first-generation BiV ICD is necessary.
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Marcapaso Artificial , Taquicardia/diagnóstico , Taquicardia/terapia , Diseño de Equipo , Falla de Equipo , Femenino , Humanos , Masculino , Persona de Mediana Edad , Prevalencia , Estudios Retrospectivos , Taquicardia/epidemiologíaRESUMEN
Despite an array of treatment modalities, the overall prognosis for patients with severe heart failure remains bleak. Biventricular pacing, or cardiac resynchronization therapy, is gaining increasing acceptance as a compelling treatment for those individuals with advanced heart failure (New York Heart Association functional class III or IV). This article provides a brief description of the atrial and ventricular conduction disturbances common in patients with advanced heart failure. Current indications for therapy are outlined, as are recent results of cardiac resynchronization therapy trials. The implant procedure is described to provide a comprehensive overview of this innovative approach to re-establishing normal electromechanical activity and synchronous right and left ventricular contractions. Patient care, before and after device implant, is also summarized. The focus on patient education throughout this article may allow it to serve as a reference for health care providers involved in the care of patients with severe heart failure.