New-onset tachycardia-bradycardia syndrome following acute non-medullary brainstem infarction.

Tachycardia-bradycardia syndrome (TBS) is a variant of sick sinus syndrome (SSS) characterized by alternating tachycardia and bradycardia. A few cases of SSS secondary to structural lesions in the medulla have been reported, but there has never been a reported case of the rare sign akin to TBS following acute non-medullary brainstem infarction. Furthermore, new-onset cardiac arrhythmias in stroke often presented in one continuous pattern - either as bradycardia or tachycardia, but instances of an alternating fashion have been rarely reported. We present the case of a 46-year-old female who developed severe dizziness with vomiting, diplopia, and slurred speech, which gradually worsened to quadriplegia, severe hypophonia, and dysphagia. Brain magnetic resonance imaging (MRI) demonstrated acute midbrain and pontine infarction. Except for neurological symptoms, the patient experienced unexpected TBS with the symptoms of excessive sweating, palpitations, and irritability without any other predisposing factors. The frequency of the episodes gradually declined until it spontaneously disappeared the 5th day after admission. Given the unpredictable nature of the tachycardia and bradycardia, it was challenging to manage the arrythmias with medications. A pacemaker was recommended, but financial reasons led the patient to reject this option. Two weeks after antithrombotic therapy and rehabilitation, she was discharged with residual symptoms of diplopia, moderate dysarthria, mild quadriplegia, and no cardiac symptoms. Our case highlighted the occurrence of TBS as a new-onset arrhythmia that can manifest during the acute phase of non-medullary brainstem infarcts. Further research into brainstem lesions contributing to TBS is warranted us to elucidate the underlying mechanisms.

Enlarged right atrium predicts pacemaker implantation after atrial fibrillation ablation in patients with tachycardia-bradycardia syndrome.

Introduction: Although catheter ablation (CA) of tachycardia-bradycardia syndrome (TBS) in patients with atrial fibrillation (AF) is considered to be an effective treatment strategy, pacemaker implantations (PMIs) are often required even after a successful CA. This study aimed to elucidate the clinical predictors of a PMI after CA. Methods: From 2011 to 2020, 103 consecutive patients diagnosed with TBS were retrospectively enrolled in the study. Among the 103 patients, 54 underwent a PMI and 49 CA of AF. During 47.4 ± 35.4 months after 1.4 ± 0.6 CA sessions, 37 (75.5%) of 49 patients were free from atrial arrhythmia recurrences. PMIs were performed in 11 patients (PMI group) and the remaining 38 did not receive a PMI (non-PMI group). Results: When comparing the PMI and non-PMI groups, there were no differences in the basic mean heart rate (P = 0.36), maximum pauses detected by 24-hour Holter-monitoring (P = 0.61), and other clinical parameters between the two groups while the right atrial area index was larger (42.1 ± 24.0 vs. 21.8 ± 8.4 cm2/m2 P = 0.002) in the PMI group than non-PMI group. The ROC curve analysis showed that the optimal cutoff point of the ratio of the right atrial area index to the left atrial area index for predicting a PMI following CA was 0.812 (Sensitivity 72.7%, specificity 71.1%, positive predictive value 42.1%, negative predictive value 90.0%, diagnostic accuracy 71.4%, AUC = 0.81). Conclusion: Right atrial enlargement prior to CA was considered to be one of the risk factors for a PMI after CA of AF.

Progression from paroxysmal to persistent atrial fibrillation in pacemaker patients with tachycardia-bradycardia syndrome: a multicenter study.

Progression from paroxysmal to persistent atrial fibrillation (AF) is occasionally encountered in patients with previous pacemaker implantation (PMI) for the treatment of tachycardia-bradycardia syndrome (TBS). We aimed to determine the rate of its incidence occurring within the early years after PMI and the predictors. We studied TBS patients who received PMI at 5 core cardiovascular centers. The end point was a conversion from paroxysmal to persistent AF. We extracted 342 TBS patients out of 2579 undergoing PMI. During 5 ± 3.1 years of follow-up, 114 (33.3%) reached the end point. The time to the end point was 2.9 ± 2.7 years. The event rates within a year and 3 years after the PMI were 8.8% and 19.6%, respectively. In the multivariate hazard analyses, hypertension (hazard ratio [HR] 3.2, P = 0.03) and congestive heart failure (HR 2.1, P = 0.04) were found to be independent predictors of the end point occurring within a year after the PMI. Congestive heart failure (HR 1.82, P = 0.04), left atrial diameter of ≥ 40 mm (HR 4.55, P < 0.001), and the use of antiarrhythmic agents (HR 0.58, P = 0.04) were independently associated with the 3-year end point. Prediction models including combinations of those 4 parameters for the 1- and 3-year incidence both exhibited a modest risk discrimination (both c-statistics 0.71). In conclusion, early progression from paroxysmal to persistent AF was less frequent than expected in the TBS patients with PMI. Factors related to atrial remodeling and no use of antiarrhythmic drugs may facilitate the progression.

Leadless pacemaker implantation in dextrocardia with situs viscerum inversus: A case report and literature review.

Leadless pacemaker implantation (LPI) has fewer device complications and reduced chance of infection compared to conventional pacemakers. Dextrocardia with situs viscerum inversus (DC+SVI) is a rare condition, which seldom leads to cardiac complications. However, its presence poses a challenge to operators in cardiac procedures. LPI reports in DC patients are scarce. We report a case of LPI in a DC+SVI patient, followed by a brief but comprehensive literature review.

Impact of atrial fibrillation ablation on long-term outcomes in patients with tachycardia-bradycardia syndrome.

Background: Reports of long-term outcomes after atrial fibrillation (AF) ablation for tachycardia-bradycardia syndrome (TBS) are limited. This study aimed to investigate the impact of radiofrequency catheter ablation (RFCA) on clinical outcomes in patients with TBS. Methods: Among 1669 patients who underwent AF ablation between January 2010 and April 2020, we retrospectively enrolled 53 patients (62.3% males; age, 67.1 ± 7.0 years) who had been diagnosed with TBS before RFCA for paroxysmal AF (TBS group). After 1:2 propensity score-matching based on age, gender, AF type, and left atrial dimension, 106 patients were assigned to the control group (non-TBS group). The atrial tachyarrhythmia (ATA) recurrence rate and rate of avoidance of permanent pacemaker implantation (PMI) were examined. Results: During a median follow-up period of 37.7 months, the ATA recurrence rate after a single ablation procedure was significantly higher in the TBS group than in the non-TBS group (51.0% vs. 38.5%; log-rank p = .008); however, the ATA recurrence rate after the final ablation procedure did not significantly differ between groups. In the TBS group, the rate of PMI avoidance after AF ablation was 92.5%. A Cox-regression multivariate analysis revealed that the presence of non-pulmonary vein/superior vena cava premature atrial contractions (odds ratio, 3.38; 95% confidence interval, 1.49-7.66; p = .004) was an independent predictor of ATA recurrence in the TBS group. Conclusions: Patients with TBS had higher ATA recurrence rates after the first ablation procedure compared to those without TBS. However, ATA recurrence after AF ablation did not necessarily result in PMI for TBS patients.

A 15-year follow-up study of radiofrequency catheter ablation for atrial fibrillation in patients with tachycardia-bradycardia syndrome.

INTRODUCTION: Catheter ablation for atrial fibrillation (AF) in patients with tachycardia-bradycardia syndrome (TBS) can be a major therapeutic option to replace permanent pacemaker implantation (PMI). However, the very long-term outcome of more than 15 years in these patients has not been elucidated. METHODS: From 2002 to 2008, 25 consecutive TBS patients (62 ± 7.9 years old, 68% male) with both AF and symptomatic sinus pauses (>3.0 s) were performed radiofrequency AF ablation. These patients were followed for 15 ± 2.7 years. RESULTS: The median longest sinus pause before the ablation procedure was 6.0 s (4.4-8.0). Following 1.6± 0.8 ablation procedures, 18 (72%) patients remained free from AF. Three (12%) patients died due to noncardiovascular causes, and seven (28%) patients underwent PMI due to symptomatic sinus pause after recurrent AF in five patients and progression of sinus node dysfunction in two patients. The median duration from the first AF ablation to PMI was 6.3 years (range: 9 days to 11.0 years). Five and two patients required PMI more than 5 and 10 years after the first ablation procedure, respectively. CONCLUSION: AF ablation prevented PMI in 72% of TBS patients for a 15-year follow-up. However, in consideration of the long duration of PMI, a continuous careful long-term follow-up was warranted.

Systemic sclerosis and tachycardia-bradycardia syndrome: a case report.

BACKGROUND: Systemic sclerosis is a multisystemic character autoimmune disease. It is characterized by vascular dysfunction and progressive fibrosis affecting mainly the skin but also different internal organs. All heart structures are commonly affected, including the pericardium, myocardium, and conduction system. However, tachycardia-bradycardia syndrome is not common in the literature as a cardiac complication of systemic sclerosis. Case presentation We report a case of tachycardia-bradycardia syndrome in a 46-year-old Moroccan woman followed for systemic sclerosis with cutaneous, vascular, and articular manifestations. The diagnosis was based mainly on patient-reported symptoms and electrocardiogram data. A permanent pacemaker was implanted, allowing the introduction of beta-blockers with good outcomes. CONCLUSIONS: This case aims to show that even minor electrocardiogram abnormalities should be monitored in this group of patients, preferably by 24-hour ambulatory electrocardiogram because they could be a good indicator of the activity and progression of cardiac fibrosis.

A Rare Presentation of Sick Sinus Syndrome: Generalized Seizures.

Cardiac and neurological disorders are the main broad etiologies for loss of consciousness. Ictal bradycardia syndrome refers to epileptic discharges that profoundly disrupt normal cardiac rhythm, resulting in cardiogenic syncope during the ictal event. Convulsive syncope is a well-described phenomenon in both adults and children in which abrupt cerebral hypoperfusion leads to brief extensor stiffening and non-sustained myoclonus. Sick sinus syndrome or tachycardia bradycardia syndrome is a common cause of arrhythmias in the elderly secondary to sinus node dysfunction. We present a case of a 91-year-old male who presented with generalized seizure with associated bradyarrhythmias with telemetry showing sinus rhythm, followed by severe bradycardia, followed by Ventricular tachycardia, followed by an episode of asystole, which likely precipitated seizures as a result of cerebral hypoperfusion. The patient had a permanent dual-chamber pacemaker. He was discharged on antiepileptics as his EEG was abnormal, which might indicate an underlying predisposition.

Risk Stratification for Atrial Fibrillation and Outcomes in Tachycardia-Bradycardia Syndrome: Ablation vs. Pacing.

Background: Catheter ablation of atrial fibrillation is an alternative treatment for patients with tachycardia-bradycardia syndrome (TBS) to avoid pacemaker implantation. The risk stratification for atrial fibrillation and outcomes between ablation and pacing has not been fully evaluated. Methods: This retrospective study involved 306 TBS patients, including 141 patients who received catheter ablation (Ablation group, age: 62.2 ± 9.0 months, mean longest pauses: 5.2 ± 2.2 s) and 165 patients who received pacemaker implement (Pacing group, age: 62.3 ± 9.1 months, mean longest pauses: 6.0 ± 2.3 s). The primary endpoint was a composite of call cause mortality, cardiovascular-related hospitalization or thrombosis events (stroke, or peripheral thrombosis). The second endpoint was progress of atrial fibrillation and heart failure. Results: After a median follow-up of 75.4 months, the primary endpoint occurred in significantly higher patients in the pacing group than in the ablation group (59.4 vs.15.6%, OR 6.05, 95% CI: 3.73-9.80, P < 0.001). None of deaths was occurred in ablation group, and 1 death occurred due to cancer. Cardiovascular-related hospitalization occurred in 50.9% of the pacing group compared with 14.2% in the ablation group (OR: 4.87, 95% CI: 2.99-7.95, P < 0.001). More thrombosis events occurred in the pacing group than in the ablation group (12.7 vs. 2.1%, OR 6.06, 95% CI: 1.81-20.35, P = 0.004). Significant more patients progressed to persistent atrial fibrillation in pacing group than in ablation group (23.6 vs. 2.1%, P < 0.001). The NYHA classification of the pacing group was significantly higher than that of the ablation group (2.11 ± 0.83 vs. 1.50 ± 0.74, P < 0.001). The proportion of antiarrhythmic drugs and anticoagulants used in the pacing group was significantly higher than that in the ablation group (41.2 vs. 7.1%, P < 0.001; 16.4 vs. 2.1%, P = 0.009). Conclusion: Catheter ablation for patients with TBS was associated with a significantly lower rate of a composite end point of cardiovascular related hospitalization and thromboembolic events. Furthermore, catheter ablation reduced the progression of atrial fibrillation and heart failure.

Long-term effect of catheter ablation on tachycardia-bradycardia syndrome: evidenced by 10 years follow up.

Background: Catheter ablation has been used for the treatment of tachycardia-bradycardia syndrome (TBS). However, data on its long-term effect of rhythm control and stroke are limited.Method and results: Patients with TBS admitted in the First Affiliated Hospital of Dalian Medical University from 2002 to 2013 were reviewed in the present study. A total of 150 patients were enrolled. Seventy-nine patients underwent catheter ablation (CA group) and 71 patients chose implantation of pacemaker (PM group). The two groups were followed up for 123.01 ± 29.68 and 120.67 ± 31.05 months respectively. The CA group underwent 1.2 ± 0.5 procedure. Of the CA group, 70.9% patients exhibited sinus rhythm without long pauses or the need of anti-arrhythmia drugs (AADs). In contrast, no patient in the PM group was free of atrial fibrillation (AF). A higher proportion in the PM group progressed to persistent AF than in that in the CA group (9.9% vs. 1.3%, p < .05). The incidence of new-onset stroke in the PM group was significantly higher than that in the CA group (15.4% vs. 5.1%, p < .05).Conclusions: Even for long-term following up, catheter ablation is effective for preventing both the tachycardia and bradycardia components for the majority of patients with TBS without the need for further pacemaker implantation. Furthermore, ablation can reduce the stroke incidence of TBS through eliminating AF and reducing the progression to persistent AF.

Clinical, echocardiographic, and pacing parameters affecting atrial fibrillation burden in patients with tachycardia-bradycardia syndrome.

BACKGROUND: The influence of various factors on atrial fibrillation (AF) development in the population of tachycardia-bradycardia syndrome (TBS) patients remains unclear. There are no data on the impact of different right ventricular pacing percentage (RVp%) profiles. AIM: The purpose of the study was to evaluate the relationship between the AF burden (AFB) and various clinical, echocardiographic, and pacing parameters in TBS patients. METHODS: We performed a prospective, one-year registry of TBS patients with documented AF referred for dual-chamber pacemaker (DDD) implantation. RESULTS: The data of 65 patients were analysed. The median 12-month RVp% and AFB was 9.4% and 1.0%, respectively. During the follow-up 14% of patients had no AF (p = 0.003), and the withdrawal of AF symptoms was observed in 49% of patients (p < 0.0001). The AFB was related to the left atrium diameter (r = 0.31, p = 0.02), especially in the subjects with left ventricular ejection fraction < 60% (r = 0.44, p = 0.04). Based on the relative change of RVp%, three groups of various RVp% profile were established: stable, decreasing, and increasing RVp%. In the stable RVp% group (n = 21) there was a quadratic correlation between the 12-month RVp% and AFB (r = 0.71, p = 0.0003). In the stable RVp% > 20% subgroup there was a significant increase of AFB in comparison to the RVp% ≤ 20% subgroup (ΔAFB 1.8% vs. 0.0%, p = 0.03, respectively). In the increasing RVp% group (n = 28) the AFB increased whereas in the decreasing RVp% (n = 16) it remained stable (ΔAFB 0.67% vs. 0.0%, p = 0.034, respectively). CONCLUSIONS: DDD implantation in TBS patients is related to a significant reduction in AF symptoms, and left atrial diameter correlates with cumulative AFB in the mid-term observation. Stable RVp% > 20% is associated with AF progression whereas lower stable RVp% may stabilise AF development. Increasing RVp% may be associated with the AFB increase in comparison to the decreasing RVp% subgroup in which AFB remains stable.

Bradyarrhythmias: Clinical Presentation, Diagnosis, and Management.

Bradyarrhythmias are common clinical findings consisting of physiologic and pathologic conditions (sinus node dysfunction and atrioventricular [AV] conduction disturbances). Bradyarrhythmias can be benign, requiring no treatment; however, acute unstable bradycardia can lead to cardiac arrest. In patients with confirmed or suspected bradycardia, a thorough history and physical examination should include possible causes of sinoatrial node dysfunction or AV block. Management of bradycardia is based on the severity of symptoms, the underlying causes, presence of potentially reversible causes, presence of adverse signs, and risk of progression to asystole. Pharmacologic therapy and/or pacing are used to manage unstable or symptomatic bradyarrhythmias.

Abordagem prática dos distúrbios de ritmo em pediatria / A practical approach to rhythm disorders in pediatrics

As arritmias podem ser causadas por alterações na geração do estímulo elétrico cardíaco, na propagação deste estímulo através do coração ou pela combinação de ambas. Normalmente, não se espera que o pediatra geral seja capaz de identificar e tratar todas as arritmias cardíacas, ficando essa tarefa para o cardiologista. Entretanto, é função do pediatra saber identificar e tratar as arritmias que se manifestam como urgênciaou emergência, ou seja, as que levam à instabilidade hemodinâmica ou choque, pois, nesses casos, a vida do paciente depende da rapidez com que as medidas terapêuticas são tomadas. Visa-se, neste artigo, demonstrar pontos básicos para facilitar a avaliação e abordagem primária das principais arritmias cardíacas pediátricas e orientar os primeiros e principais passos do tratamento.

Arrhythmias may be caused by changes in the generation of cardiac electrical stimulus, in stimulus conduction through the heart, or by a combination of both. The general pediatrician it is not usually expected to be able to identify and treat all cardiac arrhythmias, referring to the cardiologist for this task. However, pediatrician are expected to be able to identify and treat arrhythmias manifested in urgent or emergency care, i.e. those that lead to hemodynamic instability or to shock, given that, in such cases, the patient's life depends on how fast the therapeutic measures are taken. In this article we aim to demonstrate some basic pointers that facilitate the assessment and primary approach to the main pediatric cardiac arrhythmias and to guide in the first and main steps of treatment.

Preexcitation syndrome with tachycardia-bradycardia syndrome:Clinical analysis / 中国实用内科杂志

Objective To investigate the association between syncope and transient suppression of sinoatrial node in patients with preexcitation syndrome and paroxysmal supraventricular tachycardia (PSVT).Methods Twelve patients (male 8,female 4;age range:19-49 years) were enrolled due to WPW(Wolff-Parkinson-White) syndrome and syncope when the tachycardia terminated.The function of sinoatrial node was evaluated with clinical electrophysiologic study,and then radiofrequency catheter ablation (RFCA) or antitachycardia pacemaker were optimized for the patients with a follow-up of 2 to 5 years.Results Electrocardiographic features of the 12 patients were: ventricular preexcitation (type A in 7 and type B in 5) and long pause when tachycardias ended up.Electrophysiologic study revealed the function of sinoatrial node was normal.Four patients received antitachycardia pacing therapy,5 underwent RFCA,and 3 received both.The 2 to 5 years follow-up found no relapse of PSVT associated syncope.Conclusion Transient suppression of sinoatrial node might explain the mechanism of syncope with preexcitation and PSVT.However,the reason why such a small group of patients differ from the majority of preexcited cases in clinical course remains to be unsettled.The first choice of prevention and treatment for these patients should be eliminating PSVT.Conventional pacemaker implantation for preventing syncope seems to be unnecessary.