Three-year extraction experience of a novel substernal extravascular defibrillation lead in sheep.

BACKGROUND: The extravascular implantable cardioverter-defibrillator (EV ICD) with lead implantation in the substernal space may provide an alternative to transvenous and subcutaneous systems. This is the first-reported chronic extraction experience for EV ICD leads. The aim of the study is to evaluate the chronic encapsulation and extractability of EV ICD leads. METHODS: Two EV ICD leads and one transvenous lead were implanted in each of 24 mature sheep. A subset of animals was evaluated yearly for histology and lead extractability. Extractions were performed using simple traction or extraction tools. Histology evaluated the encapsulating tissue. RESULTS: At 1 year, extraction was performed successfully for two of five EV ICD leads with traction alone using ≤3.1 kg-force (kgf) and the remainder extracted successfully with extraction tools; no transvenous leads were removed with traction alone. At 2 years, no EV ICD or transvenous leads were extracted with traction alone, while at 3 years, one of eight EV ICD leads and two of four transvenous leads were extracted with traction (0.8 and ≤2.3 kgf, respectively). There was one observation of hemopericardium resulting in tamponade with EV ICD extraction but without injury to cardiovascular structures and related to the unique implant tract. Among transvenous leads, inversion of the ventricle with loss of cardiac output resulted in abandonment of traction for two animals. CONCLUSIONS: Chronic extraction of EV ICD leads from the substernal space was successfully performed using traction and simple tools through 3 years in sheep with one observation of hemopericardium that did not originate from cardiovascular injury.

Current practice in transvenous lead extraction in Latin America: Latin American Heart Rhythm Association survey.

BACKGROUND: Transvenous lead extraction (TLE) is standard of care for the management of patients with cardiac implantable electronic device infection or lead-related complications. Currently, objective data on TLE in Latin America is lacking. OBJECTIVE: To describe the current practice standards in Latin American centers performing TLE. METHODS: An online survey was sent through the mailing list of the Latin American Heart Rhythm Society. Online reminders were sent through the mailing list; duplicate answers were discarded. The survey was available for 1 month, after which no more answers were accepted. RESULTS: A total of 48 answers were received, from 44 different institutions (39.6% from Colombia, 27.1% from Brazil), with most respondents (82%) being electrophysiologists. Twenty-nine institutions (66%) performed <10 lead extractions/year, with 7 (16%) institutions not performing lead extraction. Although most institutions in which lead extraction is performed reported using several tools, mechanical rotating sheaths were cited as the main tool (66%) and only 13% reported the use of laser sheaths. Management of infected leads was performed according to current guidelines. CONCLUSION: This survey is the first attempt to provide information on TLE procedures in Latin America and could provide useful information for future prospective registries. According to our results, the number of centers performing high volume lead extraction in Latin America is smaller than that reported in other continents, with most interventions performed using mechanical tools. Future prospective registries assessing acute and long-term success are needed.

Altos umbrales de desfibrilación en un paciente con miocardiopatía hipertrófica con implante de catéter de desfibrilación subcutáneo. Reporte de un caso y revisión de la literatura / High defibrillation thresholds in a patient with hypertrophic cardiomyopathy that needed subcutaneous desfibrillation catheter

Presentamos un paciente joven con miocardiopatía hipertrófica y altos umbrales de desfibrilación que necesitó recambio de generador por agotamiento. Durante el procedimiento utilizando un desfibrilador de alta salida y luego de probar varios cambios de configuración no fue efectiva la terminación de la FV inducida por lo que requiere la colocación de un catéter de desfibrilación subcutáneo con lo que se lograron adecuados márgenes de seguridad. Se realiza una revisión de la literatura acerca de las opciones en casos de altos umbrales de desfibrilación

We present a young patient with hypertrophic cardiomyopathy and high defibrillation thresholds that needed a generatior replacement. During the procedure, a high-output defibrillator was not effective for the termination of induced ventricular fibrillation (FV), even after testing several configurations. Alternatively, safety margin were reached by placing a subcutaneous defibrillator catheter. A literature review is performed exploring options for cases where defibrillation thresholds are high

Breast cancer and pacemakers.

AIMS: The combination of breast cancer and the need for a pacemaker is infrequent, and device implantation under these circumstances may be a technical challenge with several treatment options, most of them complex. METHODS AND RESULTS: Eight patients, all women, with an average age of 69.62 ± 11.4 years. We present a technique for patients with bilateral breast cancer who need a pacemaker or those who had already implanted a device and developed a homolateral breast cancer. All the pacemakers were implanted in a neck pocket, as a first implantation or if they were moved from a prepectoral pocket to the neck. Seven patients had a good outcome and one had an infection. CONCLUSION: We suggest a simple alternative to lead extraction or epicardial approach in patients with coexisting breast cancer and the need for a rhythm control device consisting in placing the device in a neck pocket and preserving the existing leads by tunnelling them either above or below the clavicle.

Morbimortalidad de la endocarditis infecciosa asociada a dispositivos electrónicos implantables permanentes / Morbimortality of infective endocarditis associated with permanent cardiovascular implantable electronic devices

La endocarditis infecciosa (EI) asociada a dispositivos electrónicos implantables permanentes (DEIP) es una complicación de baja frecuencia pero alta mortalidad sin el tratamiento adecuado. El avance sobre el conocimiento de esta patología y el desarrollo de estrategias terapéuticas como el diagnóstico precoz, manejo de antibióticos, técnicas de extracción, entre otras, han mejorado el pronóstico de estos pacientes. Los objetivos de este estudio fueron evaluar la morbimortalidad intrahospitalaria y alejada y analizar algunos factores que justifican las diferencias con los datos de la mortalidad publicada. Se estudiaron en forma retrospectiva pacientes entre marzo/2002 y marzo/2011 con diagnóstico de EI asociada a DEIP. Se analizaron características basales, diagnósticas, terapéuticas, evolución intrahospitalaria y alejada. Se incluyeron 26 casos atendidos en nuestro hospital, 23 de los cuales fueron remitidos desde otros centros para su diagnóstico y tratamiento. La edad promedio fue de 67,5 años. Todos los pacientes recibieron antibióticos durante seis semanas y se les retiró el sistema en forma completa; en el 95% de los pacientes por vía percutánea y en 2 pacientes se requirió estereotomía mediana, atriotomía y colocación de marcapasos epicardíaco. La mortalidad fue del 4% y en el seguimiento fue nula. La morbilidad intrahospitalaria fue del 31%. En el seguimiento alejado no hubo reinfecciones u otra complicación. Como conclusión la EI es un cuadro grave que presenta una morbilidad elevada con estadías hospitalarias prolongadas, pero la mortalidad es baja. La explicación podría estar en las técnicas percutáneas, experiencia, extracción completa, el tiempo del reimplante del nuevo dispositivo y el tratamiento precoz, entre otros factores.

Infective endocarditis (IE) associated with permanent cardiovascular implantable electronic devices (CIEDs) is a complication of low frequency, but high mortality without adequate treatment. Progress on the knowledge of this disease and the development of therapeutic strategies such as early diagnosis, antibiotic management and better extraction techniques, among others, have improved the prognosis of these patients. The objectives of this study were to evaluate the in-hospital and out-of-hospital morbidity, and analyze some factors that explain the differences among the published mortality data. Patients diagnosed with IE associated with CIEDs were studied, retrospectively, between March/2002 and March/2011. We analyzed baseline, diagnostic and therapeutic characteristics, and in-hospital and out-of-hospital courses of the disease. We included 26 cases treated in our hospital, 23 of whom were referred from other centers for diagnosis and treatment. The average age of the patients was 67.5 years. All patients received antibiotics for six weeks and underwent complete removal of the device system, in 95% of patients by percutaneous extraction and 2 patients required a median sternotomy, atriotomy and epicardial pacemaker placement. Mortality was 4% and the follow up mortality was zero. The in-hospital morbidity was 31%. In the follow-ups there were no reinfections or other complications. In conclusion, IE is a serious condition that has a high morbidity with prolonged hospital stays, but with a low mortality. The explanation may lie in the use percutaneous extraction techniques, experience, complete extraction of the device system, the time of reimplantation of the new device and early treatment, among other factors.

The systolic index: a noninvasive approach for the assessment of cardiac function: implications for patients with DDD and CRT devices.

BACKGROUND: Our objective was to evaluate the systolic index (SI), the ratio between rate-corrected left ventricular ejection time (LVETc), and a preejection period surrogate (PEPsu), to assess cardiac function in patients with DDD and cardiac resynchronization therapy (CRT) pacemakers. METHODS: LVETc and PEPsu were automatically measured from electrocardiogram and finger photoplethismography. Atrioventricular (AV) and mode switch (CRT to DDD) were used as hemodynamic challenges. Performance of SI, beat-by-beat systolic blood pressure (SBP), and Doppler aortic velocity/time integral (AoVTI) were compared in 36 patients, and SI's detection of CRT to DDD mode switch in nine patients, responders to CRT. AVs were changed from 30 ms to 250 ms (20 ms steps) at constant paced heart rate, alternating with a reference AV (RefAV), to reduce hemodynamic drift. The coefficient of variation (standard deviation/mean) of SI, SBP, and AoVTI during all RefAVs were used as error marker. The percentage detection of hemodynamic changes during AV transitions was a marker of sensitivity. RESULTS: Fifty-five patients (males 62%, age 69.6 ± 17) were studied. SI detected 441 of 544 transitions (81%) versus 361 (66%) of SBP (P = 0.005). Error during RefAVs was smaller for SI (3.4%) as compared to AoVTI (7.8%, P = 0.015) and to SBP (5.7%, P = 0.005). SIs correlated with AoVTI (R from 0.71 to 0.98, all P < 0.001). SI detected all CRT to DDD changes (P < 0.001). CONCLUSION: The noninvasive SI obtained with a simple, observer-independent hemodynamic assessment procedure has higher accuracy than SBP and AoVTI and better sensitivity than SBP. It detects mechanical resynchronization in CRT and allows programming a suitable AV delay.

[Morbimortality of infective endocarditis associated with permanent cardiovascular implantable electronic devices]. / Morbimortalidad de la endocarditis infecciosa asociada a dispositivos electrónicos implantables permanentes.

Infective endocarditis (IE) associated with permanent cardiovascular implantable electronic devices (CIEDs) is a complication of low frequency, but high mortality without adequate treatment. Progress on the knowledge of this disease and the development of therapeutic strategies such as early diagnosis, antibiotic management and better extraction techniques, among others, have improved the prognosis of these patients. The objectives of this study were to evaluate the in-hospital and out-of-hospital morbidity, and analyze some factors that explain the differences among the published mortality data. Patients diagnosed with IE associated with CIEDs were studied, retrospectively, between March/2002 and March/2011. We analyzed baseline, diagnostic and therapeutic characteristics, and in-hospital and out-of-hospital courses of the disease. We included 26 cases treated in our hospital, 23 of whom were referred from other centers for diagnosis and treatment. The average age of the patients was 67.5 years. All patients received antibiotics for six weeks and underwent complete removal of the device system, in 95% of patients by percutaneous extraction and 2 patients required a median sternotomy, atriotomy and epicardial pacemaker placement. Mortality was 4% and the follow up mortality was zero. The in-hospital morbidity was 31%. In the follow-ups there were no reinfections or other complications. In conclusion, IE is a serious condition that has a high morbidity with prolonged hospital stays, but with a low mortality. The explanation may lie in the use percutaneous extraction techniques, experience, complete extraction of the device system, the time of reimplantation of the new device and early treatment, among other factors.

Transvenous extraction of pacemaker leads in infective endocarditis with vegetations ≥20 mm: our experience.

BACKGROUND: According to published evidence, treatment of infective endocarditis (IE) associated with cardiovascular implantable electronic devices (CIEDs) should include complete removal of the system. Several publications have shown that transvenous removal is an effective and safe nonthoracotomy approach in patients with large vegetations, but experiences with vegetations larger than 20 mm have rarely been reported. HYPOTHESIS: Our aim was to describe our experience in percutaneous removal of CIEDs in patients with IE with large vegetations. METHODS: The data were collected retrospectively and analyzed prospectively. We evaluated in-hospital morbidity and mortality related to percutaneous removal of vegetations ≥20 mm. This included 8 cases with a follow-up period of 20 months. We removed 100% of leads in the study population. RESULTS: Two patients experienced minor complications. No patient experienced subclavian vein laceration, hemothorax and lead fracture, or severe tricuspid regurgitation. After the removal procedure, 2 patients had symptoms compatible with pulmonary embolism. Both in-hospital mortality and mortality at follow-up were zero. CONCLUSIONS: Transvenous extraction of pacing leads with larger vegetations is a feasible technique. There was a tendency toward symptomatic pulmonary embolism in patients with vegetations larger than 20 mm; however, morbidity and mortality were not influenced. We agree with the consensus that this procedure is highly useful and that the selection of the removal techniques will depend not only on the size of vegetation but also on prior cardiopulmonary conditions, concomitant cardiac surgery, atrial septal defect with risk of paradoxical embolism, center experience, and the possibility of complete removal of the device.

Implante de cardiodesfibrilador por vía transauricular: descripción de un caso / Placement of an Implantable Cardioverter Defibrillator Thorough a Transatrial Approach: a Case Report

La trombosis de la vena cava superior es infrecuente, pero su aparición dificulta la vía de acceso para el implante de marcapasos y desfibriladores. Existen alternativas cuando no se puede utilizar la vía endovascular y la vía epicárdica es la de elección. Sin embargo, se describieron implantes de catéteres de desfibrilador por vía transauricular por toracotomía mínima con buenos resultados a largo plazo y con el logro de un umbral de desfibrilación adecuado. En esta presentación se describe el caso de un paciente con antecedentes de cardiopatía chagásica e implante de un marcapasos bicameral por enfermedad binodal que necesita un desfibrilador. Debido a que se trata de un paciente joven con accesos dificultosos se decidió utilizar la vía transauricular por toracotomía mínima conservando el catéter auricular para estimulación y sensado.

Thrombosis of the superior vena cava is an infrequent condition; yet, its presence prohibits placement of pacemakers and defibrillator devices. The epicardial approach is indicated when the venous access for lead placement is compromised. However, implantable cardioverter device placement using minithoracotomy has been described with favorable long-term outcomes, achieving an adequate defibrillation threshold. We describe the case of a patient with a history of Chagas cardiomyopathy and dual-chamber pacemaker placement due to coexisting sinus node and atrioventricular node dysfunction. We decided to use the transatrial approach via minithoracotomy leaving the atrial lead for sensing electrical activity and delivering stimulation pulses.

Pacemaker endocarditis: approach for lead extraction in endocarditis with large vegetations / Endocardite em marca-passo: abordagem na extração do cabo-eletrodo em endocardite com grandes vegetações

The presence of large lead vegetations poses additional difficulties for explantation because many methods cannot be used due to the potential hazard of embolism. We report two patients with large vegetation on the ventricular lead due to endocarditis and one of them with an atrial septal defect associated. It was applied a combined technique of transvenous lead removal and sternotomy with cardiopulmonary bypass for the complete removal of pacemaker wires. This procedure resolved the pacemakers endocarditis safely and subsequently a new transvenous device was placed on the opposite site.

A presença de grande crescimento vegetativo no eletrodo do marca-passo impõe dificuldades adicionais para a sua extração, pois alguns métodos não podem ser aplicados pelo risco potencial de embolismo. Reportamos dois pacientes com grande crescimento vegetativo no eletrodo ventricular, devido a endocardites, um deles com comunicação intraventricular associada. Foi aplicada uma técnica combinada de extração de eletrodo transvenosa e esternotomia com circulação extracorpórea para remoção completa dos cabos do marcapasso. Este procedimento resolveu a endocardite de marcapasso de maneira segura e, subsequentemente, foi colocado um novo dispositivo intravenoso no lado oposto.

Pacemaker endocarditis: approach for lead extraction in endocarditis with large vegetations.

The presence of large lead vegetations poses additional difficulties for explantation because many methods cannot be used due to the potential hazard of embolism. We report two patients with large vegetation on the ventricular lead due to endocarditis and one of them with an atrial septal defect associated. It was applied a combined technique of transvenous lead removal and sternotomy with cardiopulmonary bypass for the complete removal of pacemaker wires. This procedure resolved the pacemakers endocarditis safely and subsequently a new transvenous device was placed on the opposite site.

Transjugular approach for lead extraction.

AIMS: The purpose of this manuscript is to describe a transjugular extraction technique which permits the use of locking stylets and sheaths, for leads previously cut and retracted into the venous system and/or damaged during an extraction performed via the superior approach. METHODS AND RESULTS: A horizontal cervical incision is made over the sternocleidomastoid muscle to access the internal jugular vein between both fascicles of the muscle. The vein is ligated and through a phlebotomy a pig-tail catheter or the laparoscopic tool is introduced into the jugular vein. At the end of the procedure, a second ligature is also applied. This technique was utilized in 18 patients for the extraction of 22 leads with a mean implant duration of 91.8 months (range from 12 to 285 months). The age of the patients ranged from 19 to 87 years, (mean = 58.6 years). Out of the 22 leads extracted, 14 were ventricular pacemaker leads, 5 atrial pacemaker leads, 2 ICD leads, and 1 ventricular lead for VDD pacing. As regards the extractions, 18 were complete, 2 tips were abandoned (partial extractions), and 2 failed. CONCLUSION: This technique is especially useful if the leads to be extracted were previously cut and had retracted into the central circulation. Although our experience is based only on 18 patients and 22 leads, we can conclude that the success rate we have achieved was high and the complication rate was very low.

Doce años de extracciones de catéteres endocavitarios de marcapasos y desfibriladores en la Argentina / Twelve years of experience in pacemaker and defibrillator lead extraction in Argentina

La extracción de catéteres de marcapasos fue una práctica habitual desde que se implantó el primer marcapasos en 1958. Se presenta la experiencia sobre extracciones de catéteres por vía percutánea de 609 catéteres de marcapasos y desfibriladores, desde julio de 1993 hasta julio de 2005. La indicación más frecuente fue por infección (decúbitos y endocarditis bacteriana asociada con marcapasos). Se utilizaron distintas vías de abordaje: vena cava superior (la más frecuente), vena cava inferior, transyugular interna y transauricular. Los catéteres con mayor tiempo de implantados necesitaron del sistema de extracción con más frecuencia que los catéteres más nuevos. Los catéteres de desfibrilador tuvieron menos tiempo de implantados y requirieron el material de extracción un número mayor de veces. La eficacia fue superior al 99 por ciento. El procedimiento tiene riesgos de complicaciones que incluyen la muerte. Sin embargo, con un entrenamiento apropiado, material adecuado y experiencia en el procedimiento se puede llevar a cabo con una excelente tasa de éxito.

Doce años de extracciones de catéteres endocavitarios de marcapasos y desfibriladores en la Argentina / Twelve years of experience in pacemaker and defibrillator lead extraction in Argentina

La extracción de catéteres de marcapasos fue una práctica habitual desde que se implantó el primer marcapasos en 1958. Se presenta la experiencia sobre extracciones de catéteres por vía percutánea de 609 catéteres de marcapasos y desfibriladores, desde julio de 1993 hasta julio de 2005. La indicación más frecuente fue por infección (decúbitos y endocarditis bacteriana asociada con marcapasos). Se utilizaron distintas vías de abordaje: vena cava superior (la más frecuente), vena cava inferior, transyugular interna y transauricular. Los catéteres con mayor tiempo de implantados necesitaron del sistema de extracción con más frecuencia que los catéteres más nuevos. Los catéteres de desfibrilador tuvieron menos tiempo de implantados y requirieron el material de extracción un número mayor de veces. La eficacia fue superior al 99 por ciento. El procedimiento tiene riesgos de complicaciones que incluyen la muerte. Sin embargo, con un entrenamiento apropiado, material adecuado y experiencia en el procedimiento se puede llevar a cabo con una excelente tasa de éxito. (AU)

Automatic beat-to-beat left heart AV normalization: is it possible?

Programming the right heart AV interval to a normal value may cause a nonphysiological left heart AV due to interatrial and interventricular conduction delays, thus affecting cardiac performance. Since AV normalization at rest and exercise may be invalidated by pacing or sensing (mode) changes, the aim of this study was to (1) study the feasibility of a mode independent pacemaker (PM) algorithm for automatic beat-to-beat left AV normalization, (2) establish normal values for the time between mitral flow A wave (Af) and ventricular activation (Va), the AfVa interval, the mechanical surrogate of left AV, and (C) determine the range of values of the interatrial electromechanical delays (IAEMDs) and the effect of RA pacing. To pace with the proper right AV, the previously reported RV-paced interventricular electromechanical delay and the interatrial electromechanical delay, either P-sensed (IAEMDs) or atrial-paced (IAEMDp) are required inputs. Data were collected during diagnostic echo Doppler studies in 84 subjects divided in three groups: (1) control with narrow QRS and no structural heart disease (n = 33, age 50 +/- 21 years, 42% men); (2) patients in sinus rhythm with diverse cardiac pathologies except LBBB (n = 39, age 69 +/- 14 years, 56% men), and (3) DDD-paced patients (n = 12, mean age 71 +/- 6 years). Normal values of AfVa were established from the control group, while IAEMDs and IAEMDp and active atrial flow time (A-peak), in all subjects. The algorithm was tested by computer simulation under all possible modes with the following calculation: RAV = N + IAEMD - IVD, where RAV is the right AV, N is the desired normal AfVa value, IAEMD is either P-sensed or A-paced, and IVD is close to zero for intrinsic narrow QRS and biventricular pacing, or 79 ms for RV pacing. The results demonstrated (1) Normal (controls) AfVa: 85 +/- 15 ms (range 52-110 ms); (2) IAEMDs (All): 84 +/- 16 ms; (3) atrial pacing prolonged IAEMDs by 57 +/- 18 ms (from 93 +/- 15 to 150 +/- 25 ms, P < 0.0001); and (4) Computer simulation of rate and mode changes validated the normalization algorithm. An automatic, beat-to-beat left AV normalization algorithm to preserve a normal AfVa without a hemodynamic sensor is feasible. The normal value of AfVa is 85 +/- 15 ms.