Electrocardiogramas durante el tercer trimestre de embarazo: / Electrocardiography During the Third Trimester of Pregnancy:

RESUMEN Objetivo: Analizar las características electrocardiográficas en embarazadas sin patología cardiovascular. Material y métodos: Estudio de corte transversal, descriptivo, multicéntrico. Se incluyeron pacientes sin patología cardiovascular que cursaban el tercer trimestre de embarazo y que concurrieron a una evaluación cardiológica preparto entre abril y julio de 2020; todas ellas firmaron el consentimiento correspondiente. Resultados: Se analizaron 80 trazados. La mediana de la frecuencia cardíaca fue 82 lpm (RIC: 70-93 lpm). La mediana del eje QRS fue 54° (RIC: 39°-71°). Ondas q e infradesnivel del segmento ST en cara inferior y de V4 a V6 fueron hallazgos relativamente frecuentes. La mediana del QTc fue 422 mseg (RIC: 404 mseg-445 mseg). La mediana del tiempo del pico de la onda T a su fin fue 86 mseg (RIC: 74-95 mseg). Conclusión: Las alteraciones más frecuentes ocurrieron en DIII, DII, aVf y de V4 a V6. Las ondas q y el infraST fueron los cambios principales. Fueron infrecuentes las desviaciones del eje, la taquicardia sinusal o el QTc prolongado.

ABSTRACT Objective: The aim of this study was to analyze the electrocardiographic characteristics in pregnant women without cardiovascular disease. Methods: This was a descriptive, cross-sectional, multicenter study, including patients without cardiovascular disease in their third trimester of pregnancy, who underwent cardiac evaluation before delivery between April and July 2020. All patients signed the corresponding informed consent. Results: A total of 80 tracings were analyzed. Median heart rate was 82 bpm (IQR 70-93 bpm) and median QRS axis was 54° (IQR 39°-71°). Q waves and ST segment depression were relatively frequent in inferior leads and from V4 to V6. Median QTc was 422 msec (IQR 404-445 msec) and median time from T wave peak to T wave end was 86 msec (IQR 74-95 msec). Conclusion: The most common changes occurred in T wave peak to T wave end and from V4 to V6. Main changes included q waves and ST-segment depression. Axis deviations, sinus tachycardia or prolonged QTc were rare.

Resultados del primer registro de implante de cardiodesfibriladores y resincronizadores SAC (RENCARE) / Results of the First SAC Implantable Cardioverter-Defibrillator and Cardiac Resynchronization Therapy Registry (RENCARE)

RESUMEN Introducción: La prevención de la muerte súbita y el tratamiento de la insuficiencia cardíaca son temas de gran importancia. Para prevenir la muerte súbita y mejorar el pronóstico de la insuficiencia cardíaca se utilizan los cardiodesfibriladores y cardioresincronizadores. Objetivos: Evaluar la cantidad y tipo de dispositivos implantados en nuestro país, así como las características de los pacientes, las complicaciones agudas y las que se presentan en el seguimiento. Material y métodos: Se realizó un estudio observacional, prospectivo, multicéntrico en centros de salud con la capacidad de implantar cardiodesfibriladores y cardioresincronizadores. Se incluyeron pacientes a los que se les realizó implante de estos dispositivos desde enero del 2016 hasta enero de 2017, con un seguimiento de 12 meses. Resultados: Se incluyeron 249 pacientes (edad promedio de 64,8 ± 13,7 años, 73,9% de sexo masculino, 72,1% con Fey < 35%). La etiología subyacente de la miocardiopatía era isquémica en el 39,8%, dilatada 26,7% y chagásica en el 11,2% de los casos. El 58% de los implantes realizados fueron cardiodesfibriladores y el 39%, cardiodesfibriladores asociados con cardioresincronizadores. El 84% de los procedimientos fueron primoimplantes. La indicación más frecuente del implante fue por prevención primaria de muerte súbita (67,9%). La tasa de complicaciones menores fue del 4,4% y no se reportaron complicaciones mayores. Conclusiones: El siguiente registro evidenció una gran proporción de implantes en pacientes con cardiopatía isquémica, la indicación principal fue por prevención primaria de muerte súbita y la tasa de complicaciones fue similar a la reportada internacionalmente.

ABSTRACT Background: Prevention of sudden death and treatment of heart failure are very important topics. Implantable cardioverter-defibrillator and cardiac resynchronization devices are used to prevent sudden death and improve heart failure symptoms and prognosis. Objectives: The aim of this study was to evaluate the number, type of implanted devices, clinical characteristics of the patients and acute and follow-up complications. Methods: An observational, prospective, multicenter study was carried out in healthcare centers with the capacity to implant cardioverter-defibrillator and cardiac resynchronization devices. The study included all patients who underwent implantation of these devices from January 2016 to January 2017, with a 12-month follow-up. Results: A total of 249 patients (73.9% men) with mean age of 64.8±13.7 years, and 72.1% with ejection fraction <35%, were included in the study. The underlying cardiomyopathy etiology was ischemic in 39.8% of cases, dilated in 26.7% and chagasic in 11.2%. Fifty-eight percent of implants were implantable cardioverter-defibrillators and 39% were cardioverter-defibrillators associated with cardiac resynchronization devices. In 84% of cases, procedures were first implants. The most frequent indica-tion of implantation was for primary prevention of sudden death (67.9%). Minor complication rate was 4.4% and no major complications were reported. Conclusions: The present registry evidenced a large proportion of cardioverter-defibrillator and cardiac resynchronization implants in patients with ischemic heart disease. The main indication was for primary prevention of sudden death and the complication rate was similar to that reported internationally.

Safety and efficacy of cryoablation vs. radiofrequency ablation of septal accessory pathways: systematic review of the literature and meta-analyses.

Aims: Radiofrequency ablation (RFA) of septal accessory pathways (APs) is associated with a significant rate of first procedure failures and complications. Cryoablation is an alternative energy source but there are no studies comparing both ablation techniques. We aimed to systematically review the literature and compare the efficacy and safety of cryoablation vs. RFA of septal APs. Methods and results: We conducted two separate meta-analysis of cryoablation and RFA of septal APs and calculated the global estimates of the efficacy and safety. Sixty-four articles were included: 38 articles reporting RFA and 27 articles reporting cryoablation procedures. Additionally, we included the previously non-published cryoablation registry of septal APs performed at our institution. Overall, 4244 septal APs constitute our study population, 3495 in the RFA cohort and 749 in the cryoablation cohort. Acute procedural success rate of cryoablation was 86.0% (95% CI 81.6-89.4%) and RFA 89.0% (95% CI 86.8-91.0%). Recurrence rate of cryoablation was 18.1% (95% CI 14.8-21.8%) and RFA 9.9% (95% CI 8.2-12.0%). Long-term success rate after multiple ablation procedures of cryoablation was 75.9% (95% CI 68.2-82.3%) and RFA 88.4% (95% CI 84.7-91.3%). There were no reported cases of persistent atrioventricular block (AVB) with cryoablation and 2.7% (95% CI 2.2-3.4%) with RFA. Conclusion: Studies of RFA for treatment of septal APs report higher efficacy rates than do studies using cryoablation, but a significantly higher rate of AVB.

Differential Responses of the Septal Ventricle and the Atrial Signals During Ongoing Entrainment: A Method to Differentiate Orthodromic Reciprocating Tachycardia Using Septal Accessory Pathways From Atypical Atrioventricular Nodal Reentry.

BACKGROUND: Differential diagnosis between tachycardia mediated by septal accessory pathways (AP) and atypical atrioventricular nodal reentry can be challenging. We hypothesized that an immediate versus delayed pace-related advancement of the atrial electrogram, once the local septal parahisian ventricular electrogram (SVE) has been advanced, may help in this diagnosis. METHODS AND RESULTS: We focused on differential timing between SVE and atrial signals at the initiation of continuous right ventricular apical pacing during tachycardia. SVE advancement preceding atrial reset was defined as SVE advanced by the paced wave fronts while atrial signal continued at the tachycardia cycle. We analyzed 51 atypical atrioventricular nodal reentry (45% posterior type) and 80 AP tachycardias (anteroseptal [10], parahisian [18], midseptal [12], and posteroseptal [40]). SVE advancement preceding atrial reset was observed in 98% of atrioventricular nodal reentries during 4±1.1 cycles; this phenomena was observed in 6 (8%) of the atrioventricular reentrant tachycardia mediated by septal AP (P<0.001; sensitivity 98%; specificity 93%; positive predictive value 90%; negative predictive value 99%) and lasted 1 single cycle (P<0.001). Right posteroseptal AP tachycardias were distinctly characterized by atrial reset preceding SVE advancement (with ventricular fusion; specificity 100%; positive predictive value 100%). In 11 cases, it was impossible to achieve sustain entrainment. In all of them, the differential responses at the entrainment attempt allowed for appropriate diagnosis. CONCLUSIONS: The differential response of the SVE and the atrial electrogram at the initiation of continuous right ventricular apical pacing during tachycardia effectively distinguishes between atypical atrioventricular nodal reentry and atrioventricular reentrant tachycardia mediated by septal APs.

Seguridad del implante ambulatorio de desfibrilador automático implantable / Safety of outpatient implantation of the implantable cardioverter-defibrillator

Introducción y objetivos. Es importante desarrollar estrategias que reduzcan los costes sanitarios y mejoren la atención de los pacientes. El objetivo de nuestro estudio es analizar la seguridad del implante ambulatorio de desfibriladores automáticos implantables. Métodos. Se estudió retrospectivamente a 401 pacientes consecutivos a los que se implantó un desfibrilador automático implantable entre 2007 y 2012. Se comparó la tasa de complicaciones relacionadas con la intervención de los 232 (58%) pacientes cuyo implante se programó como ambulatorio frente a los 169 (42%) intervenidos durante ingreso hospitalario. Resultados. La media de edad era 62 ± 14 años; 336 (84%) pacientes eran varones. Los pacientes ambulatorios tuvieron, en comparación con los hospitalizados, menor fracción de eyección del ventrículo izquierdo y mayor porcentaje de indicación por prevención primaria de muerte súbita. Sólo 21 pacientes (9%) del grupo ambulatorio requirieron ingreso hospitalario. La tasa de complicaciones hasta el tercer mes tras el implante fue similar en los dos grupos (el 6,0% en ambulatorios frente al 5,3% en ingresados; p = 0,763). En el análisis multivariable, solo el tratamiento anticoagulante previo se relacionó con la presencia de complicaciones (odds ratio = 3,2; intervalo de confianza del 95%, 1,4-7,4; p < 0,01), principalmente por un incremento en la tasa de hematomas de la bolsa del dispositivo. Cada implante ambulatorio supuso un ahorro de 735 euros. Conclusiones. El implante ambulatorio de desfibrilador automático implantable es seguro y reduce los costes. En pacientes con tratamiento anticoagulante crónico, se incrementa el riesgo de complicaciones, por lo que debería recomendarse un control específico (AU)

Introduction and objectives. Strategies are needed to reduce health care costs and improve patient care. The objective of our study was to analyze the safety of outpatient implantation of cardioverter-defibrillators. Methods. A retrospective study was conducted in 401 consecutive patients who received an implantable cardioverter-defibrillator between 2007 and 2012. The rate of intervention-related complications was compared between 232 patients (58%) whose implantation was performed in the outpatient setting and 169 patients (42%) whose intervention was performed in the inpatient setting. Results. The mean age (standard deviation) of the patients was 62 (14) years; 336 (84%) were male. Outpatients had lower left ventricular ejection fraction and a higher percentage had an indication for primary prevention of sudden death, compared to inpatients. Only 21 outpatients (9%) required subsequent hospitalization. The rate of complications until the third month postimplantation was similar for outpatients (6.0%) and inpatients (5.3%); P = .763. In multivariate analysis, only previous anticoagulant therapy was related to the presence of complications (odds ratio = 3.2; 95% confidence interval, 1.4-7.4; P < .01), mainly due to an increased rate of pocket hematomas. Each outpatient implantation saved approximately €735. Conclusions. Outpatient implantation of implantable cardioverter-defibrillators is safe and reduces costs. Close observation is recommended for patients receiving chronic anticoagulation therapy due to an increased risk of complications (AU)

Safety of Outpatient Implantation of the Implantable Cardioverter-defibrillator.

INTRODUCTION AND OBJECTIVES: Strategies are needed to reduce health care costs and improve patient care. The objective of our study was to analyze the safety of outpatient implantation of cardioverter-defibrillators. METHODS: A retrospective study was conducted in 401 consecutive patients who received an implantable cardioverter-defibrillator between 2007 and 2012. The rate of intervention-related complications was compared between 232 patients (58%) whose implantation was performed in the outpatient setting and 169 patients (42%) whose intervention was performed in the inpatient setting. RESULTS: The mean age (standard deviation) of the patients was 62 (14) years; 336 (84%) were male. Outpatients had lower left ventricular ejection fraction and a higher percentage had an indication for primary prevention of sudden death, compared to inpatients. Only 21 outpatients (9%) required subsequent hospitalization. The rate of complications until the third month postimplantation was similar for outpatients (6.0%) and inpatients (5.3%); P = .763. In multivariate analysis, only previous anticoagulant therapy was related to the presence of complications (odds ratio = 3.2; 95% confidence interval, 1.4-7.4; P < .01), mainly due to an increased rate of pocket hematomas. Each outpatient implantation saved approximately €735. CONCLUSIONS: Outpatient implantation of implantable cardioverter-defibrillators is safe and reduces costs. Close observation is recommended for patients receiving chronic anticoagulation therapy due to an increased risk of complications.

Safety, long-term results, and predictors of recurrence after complete endocardial ventricular tachycardia substrate ablation in patients with previous myocardial infarction.

Conduction channels and electrograms with isolated component/late potentials are sensitive markers of the substrate of post-myocardial infarction sustained monomorphic ventricular tachycardia (VT). Ablation of all conduction channels and isolated component/late potentials (complete endocardial VT substrate ablation [CEVTSA]) during sinus rhythm could simplify and facilitate the ablation procedure, mainly in patients without references for clinical VT substrate identification. The aim of this study was to assess the safety, efficacy, and predictors of VT recurrence after CEVTSA. Electroanatomic mapping and CEVTSA were performed in 59 post-myocardial infarction patients (mean age 67 ± 9 years, mean left ventricular ejection fraction 30 ± 11%), 24 of whom did not have clinical VT substrate references. The mean areas of scar (≤1.5 mV) and dense scar (≤0.5 mV) were 76 ± 42 and 34 ± 24 cm(2), respectively; isolated component/late potentials and conduction channels were identified and ablated in 97% and 83% of patients (mean ablation area 14 ± 10 cm(2)). No life-threatening complications occurred during the procedure. After 1 year and at the end of follow-up (mean 39 ± 21 months), 81% and 58% of patients were free of VT. No differences were observed between patients with and without specific clinical VT substrate identification. Univariate analysis identified the left ventricular ejection fraction, VT cycle length (VTCL), infarct location (inferior vs anterior), and dense scar area as predictors of VT recurrence, and Cox analysis identified VTCL (hazard ratio 0.42, p <0.001) and dense scar area (hazard ratio 2.65, p <0.0006) as independent predictors. No patients with dense scar area ≤25 cm(2) and VTCL >350 ms had recurrences. In conclusion, CEVTSA is safe and effective, even in patients without clinical VT substrate identification. Scar area and VTCL are valuable predictors of VT recurrence.

Refining the indications of implantable cardioverter defibrillator in patients with left ventricular dysfunction.

Although clinical trials evaluating therapy with implantable cardioverter defibrillators (ICD) have had clear limitations, there are few interventions in which multiple trial settings over a long period have consistently produced a 20% to 30% reduction in total mortality in patients with left ventricular dysfunction. Substantial differences between the Guidelines on ICD implantation have resulted and the number of patients actually implanted following these recommendations remains relatively low. As well as this, different reasons have been proposed to explain why randomized trials of ICD versus control subjects implanted early after myocardial infarction do not show survival benefit. Moreover, many factors in addition to ejection fraction (EF) do influence the prognosis of patients with coronary disease. However, there are few tools to use this information to guide clinical decisions. Recent years have seen an ongoing debate on the further risk stratification of patients who will benefit most from ICD implantation and a combination of a few readily available clinical variables indicating advanced disease and comorbid conditions identifies ICD patients at high risk. In addition, the role of these devices in patients with nonischemic cardiomyopathies, in older patients and females, for prevention of sudden cardiac death (SCD), has long been debated. This review aims to summarize these criticisms and to refine the current indications of ICD implantation in patients with moderate-severe left ventricular dysfunction.