Impact of routine right parasternal electrocardiographic screening in assessing eligibility for subcutaneous implantable cardioverter-defibrillator.

INTRODUCTION: Between 7% and 15% of patients with an indication for an implantable cardioverter-defibrillator (ICD) are not eligible for implantation of a subcutaneous implantable cardioverter-defibrillator (S-ICD) on the basis of the result of the conventional left parasternal electrocardiographic screening (LPES). Our objective was to determine the impact of systematically performing right parasternal electrocardiographic screening (RPES) in addition to conventional LPES, in terms of increasing both the total percentage of potentially eligible patients for S-ICD implantation and the number of suitable vectors per patient. METHODS AND RESULTS: Consecutive patients from the outpatient device clinic who already had an implanted ICD, and no requirement for pacing were enrolled. Conventional left parasternal electrode position and right parasternal electrode positions were used. The automatic screening tool was used to analyze the recordings. Screenings were performed in the supine and standing positions. Overall, 209 patients were included. The mean age was 63.4 ± 13 years, 59.8% had ischemic heart disease, mean QRS duration was 100 ± 31 ms, and 69.9% had a primary prevention ICD indication. Based on conventional isolated LPES, 12.9% of patients were not eligible for S-ICD compared with 11.5% based on RPES alone (P = .664). Considering LPES and RPES together, only 7.2% of patients were not eligible for S-ICD (P < .001). Moreover, the number of patients with more than one suitable vector increased from 66.5% with isolated LPES to 82.3% (23.7% absolute increase [P < .001]). CONCLUSION: Adding an automated RPES to the conventional automated LPES increased patient eligibility for the S-ICD significantly. Moreover, combined screening increased the number of suitable vectors per eligible patient.

A scoring algorithm for the accurate differential diagnosis of regular wide QRS complex tachycardia.

BACKGROUND: The differential diagnosis of regular wide QRS complex tachycardia (RWQRST) remains the subject of numerous publications, all of which aim at diagnosis during the acute phase. Although an accurate diagnosis is necessary to make long-term decisions, it often leads to invasive testing. METHODS: Criteria with high positive predictive values (PPVs) for diagnosis can be obtained by analyzing the electrocardiogram (ECG) data during RWQRST and comparing them with these data at baseline. By assigning points to these criteria, a scoring algorithm to accurately diagnose numerous patients can be obtained. A total of 352 consecutive patients with RWQRST were included. Two electrophysiologists blind to patient condition analyzed the 16 criteria considered as having high PPVs. RESULTS: A total of 149 (42.3%) cases were supraventricular tachycardia (SVT), and 203 (57.7%) cases were ventricular tachycardia (VT). A higher percentage of patients with VT had structural heart disease (86.7% vs 16.1%). Seven of the 16 criteria analyzed had PPVs > 95%, and each criterion was assigned a score. A final score of -1 was indicative of SVT (PPV 98%); a score of 1 was indicative of VT (PPV 98%); and a score of ≥2 was indicative of VT (PPV 100%). A score of ≠0 was obtained for 51.7% of all cases of tachycardia, making it possible to reach a highly accurate diagnosis in approximately half of all cases. No cases of VT scored -1, and no cases of SVT scored ≥2. CONCLUSIONS: The current scoring system stands out for its high PPV (98%) and specificity (98%), enabling an accurate diagnosis for more than half of the patients.

A regular wide QRS complex tachycardia: What is the mechanism?

A 14-year-old girl with a history of recurrent palpitations and documented wide QRS complex tachycardia was referred for electrophysiologic study and catheter ablation.

Resultados agudos y a largo plazo tras implante contemporáneo de desfibrilador subcutáneo: experiencia en un centro / Acute and long-term results after contemporary subcutaneous implantable cardioverter-defibrillator implantation: a single-center experience

Introducción y objetivos: El desfibrilador subcutáneo (S-ICD) surge como alternativa al transvenoso. La incidencia de complicaciones es similar, y los choques inapropiados (CI) son más frecuentes que lo observado con programaciones contemporáneas en los transvenosos. Tras aprobarse en 2009 en Europa, se han implementado diversas mejoras. Se expone el resultado en un centro con el implante de S-ICD, cuya experiencia se inició tardíamente, a finales de 2013. Métodos: Estudio prospectivo observacional con inclusión de pacientes consecutivos con indicación de desfibrilador y sin indicación de estimulación permanente o resincronización cardiaca, a los que se implantó un S-ICD. Se analizaron datos del implante y seguimiento a largo plazo. Resultados: Se implantó un S-ICD a 50 pacientes que habían superado el cribado electrocardiográfico pertinente. La media de edad era 46,9 ± 15 (15-78) años, y el 72% eran varones. El 38% presentaba una fracción de eyección del ventrículo izquierdo ≤ 35%, y la cardiopatía isquémica fue la más frecuente (34%), seguida de la miocardiopatía hipertrófica (18%). Se usó la técnica intermuscular, con 3 incisiones en el 10% y 2 en el 90%. Se indujo fibrilación ventricular a 49 pacientes, con eficacia del 100% en su conversión. Tras un seguimiento medio de 18,1 (2,3-44,8) meses, no se produjeron complicaciones tardías que requirieran revisión quirúrgica ni CI (0%), y 1 paciente (2%) recibió choques apropiados. Conclusiones: Las mejoras tecnológicas, de implante y programación, junto con una selección adecuada de pacientes, han permitido obtener unos excelentes resultados agudos y a largo plazo, especialmente por la ausencia de CI y complicaciones que requirieran revisión quirúrgica

Introduction and objectives: The subcutaneous implantable cardioverter-defibrillator (S-ICD) has emerged as an alternative to the transvenous defibrillator. The incidence of complications is similar, with inappropriate shocks (IS) being more frequent than those occurring with contemporary programming of transvenous defibrillators. Several improvements have been implemented after the S-ICD was approved for use in Europe in 2009. This study reports the results of S-ICD use in a single center, whose experience began late, at the end of 2013. Methods: Prospective observational study including consecutive patients with defibrillator indication and no indication for either permanent pacing or cardiac resynchronization who underwent S-ICD implantation. Implant data and long-term follow-up were analyzed. Results: An S-ICD was implanted in 50 patients who were deemed suitable after electrocardiographic screening. The mean age was 46.9 ± 15 (range, 15-78) years and 72% were male. Thirty eight percent had left ventricular ejection fraction ≤ 35%. The most frequent heart disease was ischemic heart disease (34%), followed by hypertrophic cardiomyopathy (18%). The intermuscular technique was used, with 3 incisions in 10% and 2 incisions in the remaining 90%. Ventricular fibrillation was induced in 49 patients, with 100% effectiveness in their conversion. After a mean follow-up of 18.1 (range, 2.3-44.8) months, there were no late complications requiring surgical revision, the rate of IS was 0%, and 1 patient (2%) experienced appropriate shocks. Conclusions: Improvements in technology, implant technique and device programming, along with appropriate patient selection, have led to outstanding acute and long-term results, especially regarding the absence of both IS and complications requiring surgical revision

Paradoxical preexcitation during cryoablation of a concealed parahisian accessory pathway.

A 16-year-old male presented with an orthodromic atrioventricular reentrant tachycardia over a concealed parahisian accessory pathway (AP). Cryoablation of the AP resulted in transient manifestation of a fully preexcited sinus rhythm of parahisian AP morphology. Potential causes for the paradoxical preexcitation include inadvertent atrioventricular nodal block, sourse-sink mismatch, as well as the activation of a dormant AP capable of anterograde conduction.

Anticoagulantes orales en pacientes con fibrilación auricular no valvular y con bajo riesgo / Oral anticoagulants in non-valvular atrial fibrillation and low-risk patients

Los pacientes con fibrilación auricular no valvular y puntuación CHA2D2-VASc 1 (un único factor clínico de riesgo) suponen un grupo significativo de pacientes en la práctica clínica, que plantean cierta dificultad en cuanto a la toma de decisiones sobre si iniciar y mantener de forma crónica un tratamiento anticoagulante oral. La dificultad deriva en que, clásicamente, se ha tenido la idea de que son pacientes de bajo riesgo tromboembólico, cuando parece tratarse de un grupo heterogéneo con un riesgo tromboembólico no despreciable. Por ello, es fundamental individualizar la decisión y tener presente que, pese a discrepancias entre distintas sociedades científicas, las guías de práctica clínica de la European Society of Cardiology recomiendan tratar con anticoagulante oral. Además, hay ciertos factores de la escala CHA2D2-VASc que conllevan un mayor riesgo tromboembólico y algunos pacientes pueden presentar otros factores de riesgo no incluidos en dicha escala, que contribuyen también a incrementar el riesgo tromboembólico. A la hora de iniciar un anticoagulante oral, su elección debe individualizarse atendiendo a las características propias de cada paciente, valorando el balance riesgo-beneficio de iniciar dicho tratamiento, resaltando que los anticoagulantes orales de acción directa presentan un perfil de riesgo más favorable que los antagonistas de la vitamina K, lo cual es especialmente interesante en estos pacientes de menor riesgo. En caso de pautar un anticoagulante oral de acción directa, se ha de tener presente cuándo deben realizarse ajustes de dosis en función del perfil renal, la edad o el peso, pues un inadecuado ajuste de la pauta se asocia con un aumento de los eventos isquémicos y hemorrágicos

Patients with non-valvular atrial fibrillation and a CHA2DS2-VASc score of 1, with only one clinical risk factor, are a significant group in daily clinical practice, who represent a challenge in therapeutic decision making, especially with regard to whether to start or maintain chronic oral anticoagulant therapy. The main difficulty stems from the fact that these patients were previously believed to have a low thromboembolic risk, whereas currently they seem to be a heterogeneous group with a significant thromboembolic risk. Therefore, it is very important to individualise treatment decisions in each patient and base the selected treatment option on the European Society of Cardiology clinical practice guidelines, which recommend oral anticoagulant therapy, despite discrepancies with other scientific societies. In addition, some risk factors in the CHA2DS2-VASc score involve greater thromboembolic risk than others and some patients have other risk factors not included in CHA2DS2-VASc score, which increase their risk. When starting an oral anticoagulant treatment, the choice of agent should be individualised, bearing in mind the characteristics of each patient, and assessing the benefit-risk profile of the treatment, given that direct-acting oral anticoagulants have a more favourable profile than vitamin K antagonists, which is particularly important in lower risk patients. Finally, an important key point with direct-acting oral anticoagulants is dose adjustment according to renal function, age or weight, because an inadequate dose substantially increases the bleeding and ischaemic event rate

Acute and Long-term Results After Contemporary Subcutaneous Implantable Cardioverter-defibrillator Implantation: A Single-center Experience.

INTRODUCTION AND OBJECTIVES: The subcutaneous implantable cardioverter-defibrillator (S-ICD) has emerged as an alternative to the transvenous defibrillator. The incidence of complications is similar, with inappropriate shocks (IS) being more frequent than those occurring with contemporary programming of transvenous defibrillators. Several improvements have been implemented after the S-ICD was approved for use in Europe in 2009. This study reports the results of S-ICD use in a single center, whose experience began late, at the end of 2013. METHODS: Prospective observational study including consecutive patients with defibrillator indication and no indication for either permanent pacing or cardiac resynchronization who underwent S-ICD implantation. Implant data and long-term follow-up were analyzed. RESULTS: An S-ICD was implanted in 50 patients who were deemed suitable after electrocardiographic screening. The mean age was 46.9±15 (range, 15-78) years and 72% were male. Thirty eight percent had left ventricular ejection fraction ≤ 35%. The most frequent heart disease was ischemic heart disease (34%), followed by hypertrophic cardiomyopathy (18%). The intermuscular technique was used, with 3 incisions in 10% and 2 incisions in the remaining 90%. Ventricular fibrillation was induced in 49 patients, with 100% effectiveness in their conversion. After a mean follow-up of 18.1 (range, 2.3-44.8) months, there were no late complications requiring surgical revision, the rate of IS was 0%, and 1 patient (2%) experienced appropriate shocks. CONCLUSIONS: Improvements in technology, implant technique and device programming, along with appropriate patient selection, have led to outstanding acute and long-term results, especially regarding the absence of both IS and complications requiring surgical revision.

Estimation of the effects of multipoint pacing on battery longevity in routine clinical practice.

Aims: Multipoint pacing (MPP) permits simultaneous multisite pacing of the left ventricle (LV); initial studies suggest haemodynamic and clinical benefits over conventional (single LV site) cardiac resynchronization therapy (CRT). The aim of this study was to estimate the impact of MPP activation on battery longevity in routine clinical practice. Methods and results: Patient (n = 46) and device data were collected from two centres at least 3 months after MPP-CRT device implantation. Multipoint pacing programming was based on the maximal possible anatomical LV1/LV2 separation according to three predefined LV pacing capture threshold (PCT) cut-offs (≤1.5 V; ≤4.0 V; and ≤6.5 V). Estimated battery longevity was calculated using the programmed lower rate limit, lead impedances, outputs, and pacing percentages. Relative to the longevity for conventional CRT using the lowest PCT (8.9 ± 1.2 years), MPP activation significantly shortened battery longevity for all three PCT cut-offs (≤1.5 V, -5.6%; ≤4.0 V, -16.9%; ≤6.5 V, -21.3%; P's <0.001). When compared with conventional CRT based on longest right ventricle-LV delay (8.3 ± 1.3 years), battery longevity was significantly shortened for the MPP ≤ 4.0 V and ≤6.5 V cut-offs (-10.8 and -15.7%, respectively; P's <0.001). Maximal LV1/LV2 spacing was possible in 23.9% (≤1.5 V), 56.5% (≤4.0 V), and 69.6% (≤6.5 V) of patients. Conclusion: Multipoint pacing activation significantly reduces battery longevity compared with that for conventional CRT configuration. When reasonable MPP LV vector PCTs (≤4.0 V) are achieved, the decrease in battery longevity is relatively small which may prompt the clinician to activate MPP.

Ablación con catéter de extrasístoles ventriculares del summit ventricular izquierdo / Catheter ablation of premature ventricular contractions from the left ventricular summit

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