First in man right atrial appendage implantation of a Micra leadless pacemaker.

INTRODUCTION: Pacemaker implantation can be challenging in patients with congenital heart disease. METHODS AND RESULTS: In a patient with Ebstein disease and symptomatic sinus node dysfunction, despite multiple attempts, the Micra® pacemaker could not be implanted in the severely dilated right ventricle. In that context, and after iodine injection to confirm the appropriate location, the Micra® pacemaker was successfully implanted in the right appendage at the first attempt. CONCLUSION: Despite the recent development of dedicated dual-chamber leadless pacemaker, to the best of our knowledge, this case is the first off-label Micra® implantation in a right appendage.

Closed loop stimulation reduces the incidence of atrial high-rate episodes compared with conventional rate-adaptive pacing in patients with sinus node dysfunctions.

AIMS: Subclinical atrial fibrillation (AF) is associated with increased risk of progression to clinical AF, stroke, and cardiovascular death. We hypothesized that in pacemaker patients requiring dual-chamber rate-adaptive (DDDR) pacing, closed loop stimulation (CLS) integrated into the circulatory control system through intra-cardiac impedance monitoring would reduce the occurrence of atrial high-rate episodes (AHREs) compared with conventional DDDR pacing. METHODS AND RESULTS: Patients with sinus node dysfunctions (SNDs) and an implanted pacemaker or defibrillator were randomly allocated to dual-chamber CLS (n = 612) or accelerometer-based DDDR pacing (n = 598) and followed for 3 years. The primary endpoint was time to the composite endpoint of the first AHRE lasting ≥6 min, stroke, or transient ischaemic attack (TIA). All AHREs were independently adjudicated using intra-cardiac electrograms. The incidence of the primary endpoint was lower in the CLS arm (50.6%) than in the DDDR arm (55.7%), primarily due to the reduction in AHREs lasting between 6 h and 7 days. Unadjusted site-stratified hazard ratio (HR) for CLS vs. DDDR was 0.84 [95% confidence interval (CI), 0.72-0.99; P = 0.035]. After adjusting for CHA2DS2-VASc score, the HR remained 0.84 (95% CI, 0.71-0.99; P = 0.033). In subgroup analyses of AHRE incidence, the incremental benefit of CLS was greatest in patients without atrioventricular block (HR, 0.77; P = 0.008) and in patients without AF history (HR, 0.73; P = 0.009). The contribution of stroke/TIA to the primary endpoint (1.3%) was low and not statistically different between study arms. CONCLUSION: Dual-chamber CLS in patients with SND is associated with a significantly lower AHRE incidence than conventional DDDR pacing.

Sino-atrial nodal artery occlusion causing acute sinus node dysfunction after percutaneous coronary intervention: Case report and systematic review.

BACKGROUND: New antithrombotic medications and improved stent designs have reduced branch occlusion, although the sino-atrial nodal artery (SANA) may still be occluded after a percutaneous coronary intervention (PCI), causing sinus node dysfunction (SND). Ischemic sinus nodes are usually asymptomatic but can cause sinus arrest sometimes requiring pacemaker placement. In rare cases, junctional escape rhythms, a manifestation of sinus exit blocks after PCI, can predict cardiogenic shock. METHODS: We present a case study of a patient who underwent bifurcation PCI to the LMCA to the LCX but subsequently developed cardiogenic shock as a result of SND, a junctional escape rhythm required substantial inotropic support. This case offers an exemplification of a sparsely documented, yet infrequent manifestation of iatrogenic ischemic SND at an unorthodox site, the confluence of the LMCA-LCX. In addition, we conducted a comprehensive analysis of 22 scholarly works pertaining to the subject of sinus node dysfunction (SND) subsequent to PCI resulting from ischemia caused by stenosis or occlusion of the SANA. RESULTS: RCA was responsible for 96.1% of SND cases, whereas LCX was responsible for 3.9%. SND was asymptomatic in 49.3% of cases and junctional escape rhythm in 37.6% of symptomatic cases. 28% needed a temporary transvenous pacemaker, while 7.8% needed a permanent one. Interventional management recanalized the SANA in 5.2% of patients, restoring flow. CONCLUSION: Transient sino-atrial node ischemia after PCI can cause acute SND. Before stent implantation, doctors should consider SND. Complete plaque evaluation around the SANA is needed before choosing the best PCI procedure.

Transvenous lead advancement in pediatric pacing to overcome growth-induced lead straightening and stretching.

BACKGROUND: The stretching of the lead caused by somatic growth may lead to complications (dislodgement, fracture, failure) of transvenous leads implanted in pediatric patients. Atrial loop and absorbable ligatures may prevent it. Periodical lead advancement with lead pushing from the pocket may be an option to growth-induced stretching. Our aim was to analyze retrospectively the outcome of periodical transvenous lead advancement in children with pacemaker (PM). METHODS: A procedure of lead advancement was performed in patients with a single-chamber PM implanted for isolated congenital complete atrioventricular block or sinus node dysfunction with growth-induced lead straightening/stretching. The PM pocket was opened, the lead was released from subcutaneous adherences and was gently advanced to shape again a loop/semi-loop in the atrium without dislodging the tip. Lead data (threshold, sensing, impedance) were compared before and after the procedure. Data are described as median (25th-75th centiles). RESULTS: 14 patients with 13 VVIR and 1 AAIR PM implanted at 6.8 (5.9-8.0) years of age, 23 (19-26) kg, 118 (108-124) cm, underwent 30 advancement procedures, 1.5 (1.0-2.3) per patient, during follow-up [45 (35-63) months]. Delta between procedures was: 18 (14-25) months, 11 (7-13) cm, 6 (4-9) kg; 90% of leads were successfully advanced without complications. Three unsuccessful procedures occurred with longer times [30 (14-37) months]. Electrical lead parameters did not show significant differences pre-/post-procedures. CONCLUSION: the advancement of transvenous leads in children seems safe and effective. This procedure may be another possible choice to preserve transvenous lead position and function until growth has completed.

Transvenous Pacemaker Placement: A Review for Emergency Clinicians.

BACKGROUND: Transvenous pacemaker placement is an integral component of therapy for severe dysrhythmias and a core skill in emergency medicine. OBJECTIVE: This narrative review provides a focused evaluation of transvenous pacemaker placement in the emergency department setting. DISCUSSION: Temporary cardiac pacing can be a life-saving procedure. Indications for pacemaker placement include hemodynamic instability with symptomatic bradycardia secondary to atrioventricular block and sinus node dysfunction; overdrive pacing in unstable tachydysrhythmias, such as torsades de pointes; and failure of transcutaneous pacing. Optimal placement sites include the right internal jugular vein and left subclavian vein. Insertion first includes placement of a central venous catheter. The pacing wire with balloon is then advanced until electromechanical capture is obtained with the pacer in the right ventricle. Ultrasound can be used to guide and confirm lead placement using the subxiphoid or modified subxiphoid approach. The QRS segment will demonstrate ST segment elevation once the pacing wire tip contacts the endocardial wall. If mechanical capture is not achieved with initial placement of the transvenous pacer, the clinician must consider several potential issues and use an approach to evaluating the equipment and correcting any malfunction. Although life-saving in the appropriate patient, complications may occur from central venous access, right heart catheterization, and the pacing wire. CONCLUSIONS: An understanding of transvenous pacemaker placement is essential for emergency clinicians.

A Case of Empty Sella Syndrome with the First Clinical Manifestation of Sick Sinus Syndrome.

Empty sella syndrome (ESS) is characterized by the herniation of cerebrospinal fluid into the sella, which results in the enlargement of the sella and compression of the pituitary gland. ESS commonly accompanies pituitary dysfunction and abnormal secretion of one or more hormones, which manifests as symptoms like cold intolerance, fatigue, and memory impairment. However, the occurrence of sick sinus syndrome (SSS) in ESS has not been reported. A 66-year-old female patient was admitted to the hospital with complaints of dizziness and fatigue. Electrocardiogram (ECG) revealed sinus arrest, junctional escape rhythm, and a heart rate of 40 bpm. Then, the patient was diagnosed with SSS. Thyroid function test indicated decreased thyroxine levels and slightly elevated thyroid-stimulating hormone levels. Additionally, hyposecretion of cortisol and insulin-like growth factors was observed. Magnetic resonance imaging of the pituitary gland confirmed the diagnosis of ESS. The patient was treated with hydrocortisone and euthyrox, relieving the symptoms of dizziness and fatigue. Thyroid function tests during the follow-up period showed normal hormone levels, and ECG examination revealed no abnormalities.

Atrial Pacing Negatively Affects Left Atrial Morphological and Functional Parameters Similarly to Atrioventricular Dyssynchrony.

Background and Objectives: Atrioventricular (AV) dyssynchrony as well as atrial and ventricular pacing affect left atrial (LA) function. We conducted a study evaluating the effect of atrial and ventricular pacing on LA morphological and functional changes after dual-chamber pacemaker implantation. Materials and Methods: The study prospectively enrolled 121 subjects who had a dual-chamber pacemaker implanted due to sinus node disease (SND) or atrioventricular block (AVB). Subjects were divided into three groups based on indication and pacemaker programming: (1) SND DDDR 60; (2) AVB DDD 60 and (3) AVB DDD 40. Subjects were invited to one- and three-month follow-up visits. Three subsets based on pacing burden were analyzed: (1) high atrial (A) low ventricular (V); (2) high A, high V and (3) low A, high V. LA function was assessed from volumetric parameters and measured strains from echocardiography. Results: The high A, low V group consisted of 38 subjects; while high A, high V had 26 and low A, high V had 23. A significant decrease in reservoir and contractile LA strain parameters were only observed in the high A, low V pacing group after three months (reservoir 25.9 ± 10.3% vs. 21.1 ± 9.9%, p = 0.003, contractile -14.0 ± 9.0% vs. -11.1 ± 7.8, p = 0.018). While the re-established atrioventricular synchrony in the low A, high V group maintained reservoir LA strain at the baseline level after three months (21.4 ± 10.4% vs. 22.5 ± 10.4%, p = 0.975); in the high A, high V group, a further trend to decrease was noted (20.3 ± 8.9% vs. 18.7 ± 8.3%, p = 0.231). Conclusions: High atrial pacing burden independently of atrioventricular dyssynchrony and ventricular pacing impairs LA functional and morphological parameters. Changes appear soon after pacemaker implantation and are maintained.

Early Experience of Left Bundle Branch Pacing with Lumenless Lead in a Single Center: A Case Series.

Left bundle branch pacing (LBBP) has been subject to increasing interest over the last few years due to its capacity for physiological conduction and its advantages compared to His bundle pacing. His bundle pacing has certain limitations, such as a small pacing area for the His bundle, a high threshold that leads to battery depletion, a low R-wave amplitude that may result in atrial or His oversensing, and ventricular signal undersensing. In this case series, four patients (two female and two male) aged 62.2 ± 8.4 years old with symptomatic sick sinus disease and no scar tissue in the interventricular septum underwent LBBP. All LBBPs were done with standard LBBP using a lumenless SelectSecure 3830 lead (Medtronic®, Minneapolis, USA) with a fixed helix. The lead parameters showed a good R-wave amplitudes (13 ± 7.4 mV) and a low threshold  (0.77 ± 0.17 V @ 0.4 ms). All patients were discharged on the next day. During follow-up period of 13.3 ± 12.9 months, all patients were well and no complications were noted. In conclusion, LBBP may be as an alternative of novel conduction pacing techniques and can be done relatively easy and safe, even with limited experience center.

Sinus Node Dysfunction Triggered by Tonsillar Abscess: Effects of Vagal Nerve Compression.

BACKGROUND Compression of the vagus nerve by a pharyngeal mass is a well-documented condition that can result in sinus node dysfunction (SND). However, there is scarce literature on extrinsic vagal nerve compression from a tonsillar abscess. CASE REPORT A 59-year-old woman with a history of asthma and chronic throat discomfort presented to the Emergency Department with bradycardia, palpitations, and voice changes. Following a shellfish allergy hospitalization, an otolaryngology evaluation revealed an enlarged right tonsil, recommending tonsillectomy, but scheduling challenges persisted. The patient reported mild throat pain, dysphagia, hoarseness, rhinorrhea, and exertional dyspnea and was admitted for the evaluation of peritonsillar mass. She was found to be bradycardic with a heart rate of 47, with an electrocardiogram revealing SND. Albuterol and ipratropium nebulizers, as well as dexamethasone and pantoprazole, were initiated. With this treatment, the patient symptomatically improved with a new heart rate of 68. She was discharged with outpatient appointments, but was unfortunately lost to follow-up. CONCLUSIONS This case reveals sinus node dysfunction resulting from extrinsic vagal nerve compression by a tonsillar abscess. Pressure on the vagus nerve can trigger bradycardia and low blood pressure, possibly due to compensatory overfiring of afferent vagal nerve signals from local mass effect. Early recognition and antibiotic treatment are essential to prevent cardiac complications. Clinicians must remain vigilant for such extrinsic causes, particularly in patients with chronic sore throat and cardiac symptoms. Further research and case reports are needed to deepen our understanding of this rare yet significant association.

Atrial fibrillation ablation compared to pacemaker therapy in patients with tachycardia-bradycardia syndrome: A systematic review and updated meta-analysis.

BACKGROUND: Tachycardia-bradycardia syndrome (TBS) is a subtype of sick sinus syndrome characterized by prolonged sinus pause (≥3 s) following termination of tachyarrhythmias, primarily atrial fibrillation (AF). There is controversy regarding whether the long-term prognosis of AF ablation is superior to pacemaker implantation. This study aimed to compare the effects of AF ablation and pacemaker therapy in patients with TBS. METHODS: We conducted a comprehensive search of electronic databases, including PubMed, Cochrane, EmBase, Web of Science, and Chinese BioMedical, up until December 1, 2023. We included studies that reported the effects of AF ablation vs pacemaker therapy in patients with TBS. From this search, we identified 5 studies comprising 843 participants with TBS who underwent catheter AF ablation or pacemaker therapy. RESULTS: Our meta-analysis revealed that AF ablation and pacemaker therapy had similar effects on cardiovascular death (odds ratio [OR] = 0.62 and 95% confidence interval [CI]: 0.14-2.65), procedural complications (OR = 1.53 and 95% CI: 0.67-3.48), and cardiovascular rehospitalization (OR = 0.57 and 95% CI: 0.26-1.22). However, AF ablation provided greater benefits than pacemaker therapy in terms of all-cause mortality (OR = 0.37 and 95% CI: 0.17-0.82), thromboembolism (OR = 0.25 and 95% CI: 0.12-0.49), stroke (OR = 0.28 and 95% CI: 0.13-0.57), heart failure (OR = 0.27 and 95% CI: 0.13-0.56), freedom from AF (OR = 23.32 and 95% CI: 7.46-72.92), and prevention of progression to persistent AF (OR = 0.12 and 95% CI: 0.06-0.24). Furthermore, AF ablation resulted in a reduced need for antiarrhythmic agents (OR = 0.21 and 95% CI: 0.08-0.59). CONCLUSION: AF ablation can effectively reduce the risk of all-cause mortality, thromboembolism, stroke, heart failure, and progression to persistent AF in patients with TBS. Additionally, it may eliminate the need for further pacemaker therapy in most cases after ablation. Therefore, AF ablation is considered superior to pacemaker therapy in the management of patients with TBS.

Lead Extraction and Baffle Stenting in a Patient with Transposition of the Great Arteries.

This case report discusses a 42-year-old male with dextro-transposition of the great arteries (D-TGA) status post Mustard repair and sick sinus syndrome status post dual-chamber pacemaker implant, who developed symptomatic superior vena cava (SVC) baffle stenosis. He was treated with a combined pacemaker extraction and subsequent SVC baffle stenting. The case highlights the complexities of treating SVC baffle stenosis in the presence of cardiac implantable devices and demonstrates the efficacy of this combined approach. Furthermore, the authors delve into the intricacies of D-TGA, its surgical history, and the long-term complications associated with atrial switch procedures.

Transient Sinus Node Dysfunction Associated with Herpes Simplex Encephalitis.

Sinus arrest and inappropriate sinus bradycardia are sinus node dysfunction (SND), which cause loss of consciousness. Cardiac pacing is recommended in patients with symptoms, such as syncope or dizziness. Several conditions can induce these arrhythmias; however, whether or not intracranial infectious diseases, such as herpes simplex encephalitis (HSE), can cause secondary SND is unclear. We encountered a patient with sinus arrest and transient sinus bradycardia associated with HSE. Since cardiac pause was never monitored and the bradycardia improved after HSE treatment, HSE was suspected to be the cause of SND. Although the underlying mechanisms have not yet been completely elucidated, HSE may cause secondary SND.

Cardiomiopatia não compactada: doença do nó sinusal como manifestação inicial tratada com marcapasso / Noncompaction cardiomyopathy: sinus node disease as an initial manifestation treated with bicameral pacemaker

A cardiomiopatia não compactada é uma doença congênita, que resulta de falha da compactação do miocárdio na vida embrionária. Nesse processo, há a persistência de trabeculações e recessos profundos, que se comunicam com a cavidade ventricular e geram espessamento do miocárdio em duas camadas distintas. O aspecto clínico dessa doença tanto em crianças como em adultos é muito heterogêneo, variando desde a ausência de sintomas até a tríade composta por insuficiência cardíaca congestiva, arritmias e tromboembolismo sistêmico, porém bradicardias sintomáticas são muito raras. Relatamos o caso de uma paciente com doença do nó sinusal como manifestação inicial de cardiomiopatia não compactada

Noncompaction cardiomyopathy is a congenital disease that results frommyocardial compaction failure in embryonic life. In this process there is the persistence of deep trabeculations and recesses that communicate with the ventricular cavity, resulting in myocardial thickening in two distinct layers. The clinical aspect of this disease in both children and adults is very heterogeneous, ranging from absence of symptomatology to a triad including congestive heart failure, arrhythmias and systemic thromboembolism. However, symptomatic bradycardias are very rare. We report the case of a patient with sinus node disease as the initial manifestation of non-compaction cardiomyopathy

Tratamiento no farmacológico de la fibrilación auricular. Ablación, cardioversión eléctrica, marcapasos y cierre de la orejuela / Nonpharmacological treatment of atrial fibrillation: Ablation, electrical cardioversion, pacemakers, and left atrial appendage closure

En este artículo se hace una puesta al día sobre los tratamientos no farmacológicos de la fibrilación auricular. En primer lugar, se revisa el estado actual de la ablación repasando técnicas, indicaciones y resultados. En segundo lugar, se revisan las indicaciones, las precauciones y los resultados de la cardioversión eléctrica. Se analiza asimismo el papel de los marcapasos en pacientes con fibrilación auricular, tanto en el control de la frecuencia cardiaca de los pacientes con fibrilación auricular permanente y difícil control farmacológico como aquellos con fibrilación auricular paroxística y síndrome de bradicardia/taquicardia. Por último, se revisa el estado actual de los dispositivos de cierre de orejuela izquierda para pacientes con factores de riesgo tromoboembólico y limitaciones para el tratamiento con anticoagulantes orales (AU)

This article provides an update on the nonpharmacological treatment of atrial fibrillation. First, the current status of ablation, including indications, techniques and outcomes, is reviewed. Second, the indications for electrical cardioversion, the precautions that have to be taken and the outcomes achievable are summarized. In addition, there is a discussion of the role of pacemakers for heart rate control in two groups of patients with atrial fibrillation: those with permanent atrial fibrillation and those in whom pharmacological control is difficult, such as patients with paroxysmal atrial fibrillation or bradycardia- tachycardia syndrome. Finally, an overview is presented of the devices currently used for left atrial appendage closure in patients with a high thromboembolic risk and a contraindication to oral anticoagulants (AU)

Implante de marcapasso cardíaco definitivo por disfunção do nó sinusal, utilizando a veia cava superior, após angioplastia do trajeto em pós-operatório tardio de operação de Mustard e Senning / Permanent cardiac pacemaker implatation due to sinus node dysfunction, using the superior vena cava, after angioplasty in the late postoperative period of Mustard and Senning procedure

A síndrome do nó sinusal está comumente vinculada às lesões de células sinusais ou da junção sinoatrialou a afecções do tecido intersticial que circunda essas células. Nos casos avançados, o marcapasso cardíaco artificialé o tratamento mais difundido. O caso descrito relata a síndrome do nó sinusal de um paciente em evolução tardiado pós-operatório de operação de Mustard e Senning com complicações anatômicas, levando à necessidade deimplante de marcapasso definitivo, após angioplastia do trajeto, utilizando a veia cava superior.

Sick sinus syndrome is usually related to lesions of the sinus node and sinoatrial node cells or tocollagen tissue disease surrounding these cells. In advanced cases, pacemaker implantation is the most widespreadtreatment option. This is a case report of a patient with sick sinus syndrome in the late postoperative period ofMustard and Senning procedure with anatomical complications requiring definitive pacemaker implantationafter angioplasty through the superior vena cava.

Implante de marcapasso cardíaco definitivo em paciente com síndrome bradicardia-taquicardia, transplantado renal e com persistência de veia cava superior esquerda / Pacemaker implantation in a patient with bradycardia-tachycardia syndrome, kidney transplantation and persitent left superior vena cava

A persistência da veia cava superior esquerda é rara, principalmente quando associada a ausência da veiacava superior direita, e mais ainda quando associada a síndrome bradicardia-taquicardia. Relata-se o caso em queo diagnóstico dessa anomalia venosa foi feito durante o implante de marcapasso cardíaco artificial definitivo paratratamento de síndrome bradicardia-taquicardia. O paciente havia sido submetido a transplante renal e apresentavafunção renal limítrofe, razão pela qual se optou por não utilizar contraste para realização de venografia, dandopreferência à análise do trajeto do fio guia.

Persistent left superior vena cava is a rare anomaly, mainly when associated with absent right superiorvena cava, especially when associated with bradycardia-tachycardia syndrome. We report the case of a patient,whose diagnosis of venous anomaly was made during definitive artificial pacemaker implantation for treatment ofbradycardia-tachycardia syndrome. The patient had been submitted to a kidney transplantation and had borderlinerenal function, and therefore we chose not to use a guidewire instead of contrast media to perform venography.

Comportamiento de la estimulación cardiaca en Cienfuegos durante el quinquenio 2005-2009 / Cardiac pacing in Cienfuegos from 2005 to 2009

Introducción: la implantación de un marcapaso permanente mejora la función cardiaca y la calidad devida de los pacientes con necesidad de estimulación eléctrica cardiaca. Objetivo: describir las característicasde los pacientes sometidos a implante de marcapasos permanentes y sus resultados, en el quinquenio deenero de 2005 a diciembre de 2009 en el Hospital General Universitario Dr Gustavo Aldereguía Lima deCienfuegos. Métodos: se realizó un estudio descriptivo, retrospectivo a un total de 300 pacientes a quienes seles implantó marcapasos permanentes en el Servicio de Cardiología del Hospital General Universitario DrGustavo Aldereguía Lima de Cienfuegos, en el quinquenio 2005 2009. Se recogieron los datos generales de los pacientes, el diagnóstico que motivó laindicación, el modo de estimulación empleado, la vía de abordaje y las complicaciones presentadas.Resultados: el grupo de edad que predominó fue el de los ancianos mayores de 75 años, hubo predominio del sexo masculino. La principal intervención realizada fue lade un primer implante mediante disección de la vena cefálica. Las causas más frecuentes de implante fueron: los bloqueos de la conducción auriculoventricular y la enfermedad del nodo sinusal. El tipo de estimulaciónmás usado fue el VV-VVIR. Las principales complicaciones fueron: el desplazamiento del electrodo,el hematoma y el síndrome de marcapasos. Conclusión: en Cienfuegos se continúa incrementando el número de pacientes con necesidad de estimulación eléctrica cardíaca, con predominio en los pacientes ancianos y el tipo de estimulación monocameral, se hanobtenido buenos resultados con un bajo número de complicaciones(AU)

Introduction: permanent artificial pacemaker implantation improves cardiac function and life quality ofpatients requiring cardiac pacing. Objective: to describe the characteristics of patients undergoingpermanent artificial pacemaker implantation and their results, in the period from January 2005 to December2009 in the General University Hospital Dr Gustavo Aldereguía Lima. Methods: a descriptive study was conducted. The sample consisted of 300 patients whowere implanted with permanent artificial pacemakers in the Cardiology Service of the General University Hospital Dr Gustavo Aldereguía Lima in Cienfuegos, from 2005 to 2009. General data were collected from patients such as diagnosis, pacing mode used, surgical approach and complications. Results: the predominant age group was that of elderlies over 75 years old, and mostly males were predominant. The main action taken was that of a first implant using the cephalic vein dissection. The most common causes of implant were blocks theatrioventricular conduction and sinus node disease. The type of stimulation used was the VV-VVIR. Majorcomplications included displacement of the electrode, hematomas and the pacemaker syndrome. Conclusion:the number of patients requiring cardiac electrical stimulation continues to increase in Cienfuegos. Elderlypatients and the type of single-chamber pacing are predominant. Good results have been obtained with few complications(AU)

Implantation of lumenless pacing leads at the inter-atrial septum and right ventricular outflow tract with deflectable catheter-sheath / 华中科技大学学报（医学）（英德文版）

Current permanent right ventricular and right atrial endocardial pacing leads are implanted utilizing a central lumen stylet. Right ventricular apex pacing initiates an abnormal asynchronous electrical activation pattern, which results in asynchronous ventricular contraction and relaxation. When pacing from right atrial appendage, the conduction time between two atria will be prolonged, which results in heterogeneity for both depolarization and repolarization. Six patients with Class I indication for permanent pacing were implanted with either single chamber or dual chamber pacemaker. The SelectSecure 3830 4-French (Fr) lumenless lead and the SelectSite C304 8.5-Fr steerable catheter-sheath (Medtronic Inc., USA) were used. Pre-selected pacing sites included inter-atrial septum and right ventricular outflow tract, which were defined by ECG and fluoroscopic criteria. All the implanting procedures were successful without complication. Testing results (mean atrial pacing threshold: 0.87 V; mean P wave amplitude: 2.28 mV; mean ventricular pacing threshold: 0.53V; mean R wave amplitude: 8.75 mV) were satisfactory. It is concluded that implantation of a 4-Fr lumenless pacing lead by using a streerable catheter-sheath to achieve inter-atrial septum or right ventricular outflow tract pacing is safe and feasible.

Efeitos da associação da estimulação atrial dinâmica em duplo sítio atrial com atenolol na prevenção da fibrilação atrial recorrente / Effects of the association of dual-site dynamic atrial overdrive and atenolol in preventing recurrent atrial fibrillation

OBJETIVO: Avaliar os efeitos da estimulação atrial otimizada (EAO) (estimulação duplo-sítio atrial, freqüência acima da intrínseca e algoritmo funcional específico) e uso de atenolol, na prevenção da fibrilação atrial (FA) recorrente. Desfecho primário: quantificar a taxa de episódios de FA. Desfechos secundários: qualidade de vida, avaliação de sintomas específicos cardiovasculares, taxa de internações hospitalares, taxa de cardioversões elétricas e farmacológicas e eventos cardíacos adversos. MÉTODOS: Vinte e sete pacientes com FA paroxística recorrente e doença do nó sinusal foram submetidos ao implante de marcapasso duplo-sítio atrial e ventricular e iniciaram com atenolol 100 mg/dia, a seguir foram randomizados em dois grupos, grupo I (3 meses iniciais com EAO e algoritmo especifico ligado e mais 3 com o mesmo desligado) e grupo II (seqüência inversa do grupo I). O modo de estimulação foi DDDR e após 3 meses, foram submetidos à avaliação clínica e eletrônica do sistema de estimulação - mudança automática de modo (AMS), Holter de 24 horas, ecocardiograma e questionário SF-36. Em seguida, foram cruzados e após 6 meses, nova avaliação. RESULTADOS: Pacientes com EAO, quando comparados ao grupo com algoritmo desligado, apresentaram menores taxas de: FA/semana (p<0,001), ativações do AMS (p<0,01), hospitalizações (p<0,001), cardioversões (p<0,001), além de melhores índices dos componentes físico e mental da qualidade de vida. CONCLUSÃO: A terapêutica híbrida, EAO associada ao uso de atenolol, reduziu a taxa de recorrência de FA e proporcionou melhora clínico funcional de pacientes com bradiarritmias sintomáticas.

OBJECTIVE: Evaluate the effects of optimized atrial stimulation - OAS (dual-site atrial pacing, heart rate above the intrinsic rate, and specific functional algorithm), and the use of atenolol in preventing recurrent atrial fibrillation (AF). Primary endpoint: to quantify the rate of AF episodes. Secondary endpoints: assessment of quality of life, specific cardiovascular symptoms, rate of hospital admissions, rate of electrical and pharmacological cardioversions, and adverse cardiac events. METHODS: Twenty-five patients with recurrent episodes of paroxysmal AF and sinus node disease had dual-site atrial and ventricular pacemakers implanted, and were started on atenolol, 100 mg/day. Next, they were randomized to two groups: GROUP I: first three months with OAS and the specific pacing algorithm (DAO) turned on, and three more months with the algorithm off. GROUP II: the inverse sequence to GROUP I. The pacing mode chosen was DDDR, and after three months patients underwent clinical and electronic evaluations of the stimulation system by: automatic mode switch (AMS), 24-hour Holter monitoring, Doppler echocardiogram, and SF-36 questionnaire. Following, a crossover comparison took place, and a new assessment was performed six months later. RESULTS: When compared to the group with the algorithm turned off, OAS patients had lower rates of: AF/week (p < 0.001); AMS activations (p < 0.01); hospitalizations (p < 0.001); cardioversions (p < 0.001), and higher scores on the physical and mental components of quality of life. CONCLUSION: The hybrid therapy adopted, OAS associated with the use of atenolol, reduced the rate of recurrent AF and improved the clinical-functional status of patients with symptomatic bradyarrhythmias.

Implante de marcapasos a través de la vena cava superior izquierda persistente. Reporte de un caso / Pacemaker lead implant via the persistent left superior vena cava

Antecedentes: La persistencia de la vena cava superior izquierda (VCSIP) es una anomalía estructural infrecuente y asintomática, presente en el 0.5% de la población general. Habitualmente se descubre de forma incidental, y es durante el implante de marcapasos cuando adquiere relevancia anatómica. La vía de abordaje venoso para el implante de marcapasos definitivos más utilizada en la actualidad es a través de la subclavia izquierda; la VCSIP dificulta, aunque no imposibilita el implante del o los electrodos para la estimulación eléctrica auricular o ventricular. El presente reporte está enfocado como referencia práctica para el diagnóstico y consideraciones técnicas durante el implante. Presentación del caso: Mujer de 26 años de edad en quien se documentó enfermedad intrínseca del nodo sinusal sintomática, variedad paros sinusales. Durante el abordaje venoso, la clave diagnóstica que hizo sospechar la anomalía fue la trayectoria medial del electrodo, corroborándose por venografía la desembocadura de la VCSIP en el seno coronario y su drenaje al atrio derecho. Se avanzó sin dificultad un electrodo de fijación activa implantándolo en la pared libre anterosuperior de la aurícula derecha. Tras 24 meses de seguimiento no se han presentado complicaciones y la paciente cursa asintomática. Discusión: La VCSIP es una anomalia congénita rara. Además de relacionarse con otras malformaciones congénitas, podría tener implicaciones desde el punto de vista de su desarrollo morfológico en los trastornos de la formación y conducción del impulso cardíaco. La falta de regresión de la vena cardinal izquierda puede influir en gran medida en el desarrollo ontogénico del nodo sinusal, el nodo auriculoventricular y el haz de His, relacionándose por lo tanto con diversos trastornos del ritmo. En casos de difícil manipulación del electrodo a través del seno coronario, se recomienda el abordaje venoso derecho después de visualizar la vena cava por venografía o ecocardiografía pues su ausencia o hipolasia (defecto que se reporta hasta en el 10% de los casos) representa un obstáculo aún mayor y que debiera sugerir el implante epicárdico. Conclusión: Ahora que la mayoría de implantes de marcapasos definitivos se abordan vía vena subclavia izquierda, el operador debe conocer esta anomalía venosa, que puede plantear dificultades técnicas en el implante de los electrodos. El conocimiento de esta anomalía puede ser de utilidad para otras especialidades que requieran el implante de catéteres vasculares permanentes a través de la vena subclavia izquierda.

Background: Persistent left superiorvena cava (PLSVC) is a structural, asymptomatic and infrequent anomaly, present in 0.5% of the general population. Typically the diagnosis reveals itself unexpectedly at the time of pacemaker implantation, when it acquires anatomic relevancy. Several techniques are used forthetransvenous approach to enter the central venous circulation; the left subclavian vein has become a common access site for electrode implantation and, occasionally, one can find an anomalous venous structure such as a PLSVC. Placement of electrodes through this anomalous venous structure can prove challenging, if not impossible. The present report tries to explore aspects of transimplantation diagnosis from a practical point of view. It also address the knowledge of anatomy, implant technique and radiographic orientation. Case presentation: Twenty-six-year-old woman with confirmed Symptomatic Sick Sinus Syndrome variety Sinus Arrest. The diagnosis of PLSVC was discovered unexpectedly at the time of the transvenous approach. The tip for the diagnosis was the "unusually medial" position of the lead, and the venogram showed the venous traject towards the coronary sinus and drainage into the right atrium. An active-fixation screw-in electrode was positioned in the antero-superior margin of the free wall of the right atrium. After 24 months of successful placement of the pacemaker, the patient is asymptomatic. Discussion: PLSVC is a rare congenital vascular abnormality. Besides its association with congenital anomalies, its most relevant clinical implication is the association with disturbances of cardiac rhythm, impulse formation and conduction. The ontogenetic development of the sinus node, the atrioventricular node, and the His bundle might be heavily influenced by the lack of regression of the left cardinal vein. When isolated, the PLSVC is usually not recognized until left superior approach to the heart is required, when it becomes ...