Holter monitoring represents a valuable diagnostic tool to document intermittent arrhythmias in the work-up of, for example, syncope, presyncope, collapse, falls, dizziness, stroke, palpitations, and a rapid heartbeat. In addition, it may help in the diagnosis of intermittent ischemia and channelopathies, particularly in the form of 12-lead Holter monitoring. Continuous ECG registration typically lasts from 24-48 h. The use of Holter monitoring is limited in patients with rare symptoms (< 1 × per month) and in recordings full of artifacts. The interpretation of a Holter recording combines an automatic analysis with a manual reassessment. The clinical relevance of many arrhythmias can only be considered together with symptoms and activity of the patient at the time of the event. Therefore, a patient diary accompanying the ECG recording is crucial. Systematic assessment of the ECG recording and knowledge about a number of pitfalls in Holter monitoring can optimize the interpretation of the recording.
UNASSIGNED: Das Langzeit-EKG stellt ein wertvolles Diagnostikum zur Dokumentation intermittierender Arrhythmien in der Abklärung von z. B. Synkopen, Präsynkopen, Kollaps, unklaren Stürzen, Schwindel, Schlaganfallursachen, Palpitationen und Herzrasen dar. Auch in der Diagnostik von Ischämie und Kanalerkrankungen kann es hilfreich sein, v. a. als 12-Kanal-Langzeit-EKG. Die Dauer des kontinuierlich aufzeichnenden Langzeit-EKGs liegt meist zwischen 24 und 48 h. Limitiert ist die Aussagekraft des Langzeit-EKGs bei seltenen Symptomen (< 1-mal pro Monat) und bei artefaktreicher Aufzeichnung. Die Auswertung erfolgt optimalerweise mittels manueller Kontrolle einer automatischen Voranalyse. Die Bedeutung vieler Arrhythmien kann erst im Zusammenhang mit der Symptomatik und vor dem Hintergrund der Aktivität des Patienten eingeschätzt werden, weshalb ein parallel zur EKG-Aufzeichnung geführtes Patiententagebuch essenziell ist. Eine systematische Befundung und die Berücksichtigung zahlreicher Fallstricke optimieren die Interpretation eines Langzeit-EKGs.

We report two clinical cases assessed in our minor ailment service presenting with symptoms suggestive of common digestive disorders. Both patients were treated with narrow therapeutic index drugs (lithium carbonate and digoxin, respectively). In both cases, medication analysis revealed that referred symptoms might be elicited by these drugs: abdominal discomfort is a frequent adverse reaction in long term treatments with lithium carbonate while in the case of digoxin symptomatology was found to be accompanied by bradycardia. Thus, we propose two different pharmaceutical interventions, one being an urgent general practitioner referral. Pharmacotherapy assessment during minor ailment service, focused on narrow therapeutic index drugs, is a key point in discriminating minor ailments from potential life-threatening situations.

Neonatal lupus may be associated with severe cardiac conduction problems, including high-degree or complete atrioventricular (AV) block, necessitating immediate pacemaker implantation during the neonatal period. However, cardiac manifestations of neonatal lupus may extend beyond AV block. Our case was a full-term female neonate, who presented with fetal arrhythmia and bradycardia with a heart rate of approximately 70-75 beats per minute after birth. Neonatal lupus was diagnosed later due to positive maternal and neonatal anti-SSA/Ro antibody. High-degree AV block was considered initially but bigeminy premature atrial contractions (PACs) with block was confirmed through a detailed evaluation of an electrocardiogram, which demonstrated unfixed PP intervals and fixed RR intervals. Atrial tachycardia (AT) developed when the neonate was 23 days old. The key point that differentiates high-degree AV block from PACs with block is the PP interval. The PP interval is fixed in high-degree AV block and unfixed in PACs with block. Careful differential diagnosis is required in neonates with bradycardia because it may lead to very different management. Our case presents a good illustration of why these arrhythmias need to be differentiated. Furthermore, our case may be the first of neonatal lupus with AT.

UNASSIGNED: Observational studies have shown that heart rate (HR), heart rate variability (HRV), P-wave terminal force, P-wave duration, T-wave amplitude and PR interval are associated with risk factors for atrial fibrillation (AF) or bradycardia. Arrhythmias are associated with many causes of hospitalization. However, observational studies are susceptible to confounding factors that have not yet been identified. The objective of this study was to clarify the causal relationships by Mendelian randomization analysis.
UNASSIGNED: We conducted a two-sample and multivariate Mendelian randomization (MVMR) analysis using genome-wide association study (GWAS) data from a European population to assess the total and direct causal effects of HR, three HRV traits, P-wave terminal force, P-wave duration, T-wave top amplitude in five-lead modes, and the PR interval on the risk of AF (N=191,205), bradycardia (N=463,010), and supraventricular tachycardia (SVT) (N=463,010).
UNASSIGNED: The results of the univariate MR analysis revealed the following significant causal effects: the higher the genetically predicted PR interval, the lower the risk of AF; the higher the HR and T-wave top amplitude (aVR leads and V3 + V4 + aVL leads), the lower the risk of bradycardia; and the higher HR and the lower PR interval, the higher the risk of SVT. The multivariate MR results indicated that the HRV_standard deviation of the normal-to-normal (SDNN) interval had an independent causal effect on the risk of AF [odds ratio (OR): 0.515; 95% confidence interval (CI): 0.278-0.954; P=0.03], and the T-wave top amplitude in the aVR leads (OR: 0.998; 95% CI: 0.996-0.999; P<0.001) and the HRV_SDNN (OR: 0.988; 95% CI: 0.976-1.000; P=0.045) had independent causal effects on the risk of bradycardia.
UNASSIGNED: The HRV_SDNN had an independent causal effect on AF, while the HRV_SDNN and T-wave top amplitude in the aVR leads had independent causal effects on bradycardia, which suggests that some of the electrocardiographic parameters have preventive effects on the incidence of AF and bradycardia.

The impact of age (≥ 85 vs < 85 years) on clinical outcomes and pacemaker performance of conduction system pacing (CSP) compared to right ventricular pacing (RVP) were examined. Consecutive patients from a prospective, observational, multicenter study with pacemakers implanted for bradycardia were studied. The primary endpoint was a composite of heart failure (HF)-hospitalizations, pacing-induced cardiomyopathy requiring cardiac resynchronization therapy or all-cause mortality. Secondary endpoints were acutely successful CSP, absence of pacing-complications, optimal pacemaker performance defined as pacing thresholds < 2.5 V, R-wave amplitude ≥ 5 V and absence of complications, threshold stability (no increases of > 1 V) and persistence of His-Purkinje capture on follow-up. Among 984 patients (age 74.1 ± 11.2 years, 41% CSP, 16% ≥ 85 years), CSP was independently associated with reduced hazard of the primary endpoint compared to RVP, regardless of age-group (< 85 years: adjusted hazard ratio [AHR] 0.63, 95% confidence interval [CI] 0.40-0.98; ≥ 85 years: AHR 0.40, 95% CI 0.17-0.94). Among patients with CSP, age did not significantly impact the secondary endpoints of acute CSP success (86% vs 88%), pacing complications (19% vs 11%), optimal pacemaker performance (64% vs 69%), threshold stability (96% vs 96%) and persistent His-Purkinje capture (86% vs 91%) on follow-up (all p > 0.05). CSP improves clinical outcomes in all age-groups, without compromising procedural safety or pacemaker performance in the very elderly.

Anti-N-methyl-D-aspartate receptor (anti-NMDAR) encephalitis is the most common form of autoimmune encephalitis, presenting with various psychiatric manifestations, including behavioral and cognitive impairments, movement disorders, decreased consciousness, dysphasia, seizures, and autonomic dysfunction. Autonomic dysfunction may involve hyperthermia, apnea, hypotension, tachycardia, and life-threatening manifestations of sinus node dysfunction (SND), such as bradycardia, sinus pause or arrest, and asystole. The severity and significance of SND are critical, as it is not uncommon for these patients to progress into asystolic cardiac arrest, potentially contributing to morbidity and mortality. Accordingly, we present the case of an 18-year-old female with anti-NMDAR encephalitis who experienced multiple episodes of sinus pause/arrest and asystolic cardiac arrest, achieving a return of spontaneous circulation after successful CPR in all instances, ultimately requiring permanent pacemaker implantation. Additionally, we performed a literature review and analyzed 23 similar anti-NMDAR encephalitis cases with SND manifestations, including sinus pause/arrest or asystolic cardiac arrest, to identify common risk factors and describe management strategies and outcomes. Moreover, we investigated the potential association between teratoma and permanent pacemaker use in SND.

BACKGROUND: Fludarabine is a chemotherapeutic agent with lymphodepleting effects that is increasingly used as part of a conditioning regimen prior to allogeneic stem cell transplantation. Fludarabine is generally considered a relatively safe medication with only rare cases of cardiotoxic side effects.
METHODS: Here, we present a case of a 30-year-old woman who was undergoing conditioning for a haploidentical cell transplantation for treatment of Fanconi anemia with a 5-day course of daily fludarabine infusion. After her second fludarabine infusion, she was noted to have ectopic atrial bradycardia that resolved with supportive therapy and completion of fludarabine infusion.
CONCLUSIONS: We report the first case of ectopic atrial bradycardia associated with fludarabine. Although rare and transient, clinicians should recognize this rare cardiotoxic side effect of fludarabine.

A primigravida at 36 weeks with gestational diabetes mellitus and hypothyroidism and no prior chronic medical illness was admitted for safe confinement. A cesarean section was required to deliver the baby with breech presentation complicated by a slow progression of labor. Asymptomatic sinus bradycardia with a heart rate of 40 per minute was observed during the induction of anesthesia. Before bupivacaine administration for spinal anesthesia, she was administered pantoprazole 40 mg and ondansetron 4 mg intravenously. ECG recording showed a type 1 Mobitz second-degree heart block. Follow-up ECG showed progression of heart block to type 2 Mobitz second-degree heart block. The second-degree heart block persisted for 16 hours, during which the patient was asymptomatic, and the ventricular rate was maintained at a range of 60-80 per minute. After normalization of rhythm, the patient was observed in the ICU. She received another dose of ondansetron 4 mg intravenously for vomiting, and the heart block recurred. The rhythm disturbance was attributed to ondansetron. Her rhythm normalized after 36 hours, and she was subsequently discharged home three days later.

UNASSIGNED: Bradycardia is more common among well-trained athletes than in the general population, but the association with pacemaker implantations is less known. We investigated associations of endurance training with incidence of bradycardia and pacemaker implantations, including sex differences and long-term outcome, in a cohort of endurance trained individuals.
UNASSIGNED: All Swedish skiers who completed >1 race in the cross-country skiing event Vasaloppet between 1989 and 2011 (n=209 108) and a sample of 532 290 nonskiers were followed until first event of bradycardia, pacemaker implantation, or death, depending on end point. The Swedish National Patient Register was used to obtain diagnoses. Cox regression was used to investigate associations of number of completed races and finishing time in Vasaloppet with incidence of bradycardia and pacemaker implantations. In addition, Cox regression was used to investigate associations of pacemaker implantations with death in skiers and nonskiers.
UNASSIGNED: Male skiers had a higher incidence of bradycardia (adjusted hazard ratio [aHR], 1.19 [95% CI, 1.05-1.34]) and pacemaker implantations (aHR, 1.17 [95% CI, 1.04-1.31]) compared with male nonskiers. Those who completed the most races and had the best performances exhibited the highest incidence. For female skiers in Vasaloppet, the incidence of bradycardia (aHR, 0.98 [95% CI, 0.75-1.30]) and pacemaker implantations (aHR, 0.98 [95% CI, 0.75-1.29]) was not different from that of female nonskiers. The indication for pacemaker differed between skiers and nonskiers, with sick sinus syndrome more common in the former and third-degree atrioventricular block in the latter. Skiers had lower overall mortality rates than nonskiers (aHR, 0.16 [95% CI, 0.15-0.17]). There were no differences in mortality rates by pacemaker status among skiers.
UNASSIGNED: In this study, male endurance skiers had a higher incidence of bradycardia and pacemaker implantations compared with nonskiers, a pattern not seen in women. Among male skiers, those who completed the most races and had the fastest finishing times had the highest incidence of bradycardia and pacemaker implantations. Within each group, mortality rates did not differ in relation to pacemaker status. These findings suggest that bradycardia associated with training leads to a higher risk for pacemaker implantation without a detrimental effect on mortality risk.

To study the complications and effectiveness of the treatment of chronic arrhythmias with cardiac Ganglion Plexus (GP) ablation, and to explore the value of the treatment of chronic arrhythmias with GP ablation.
This study was a one-arm interventional study of patients from the first hospital of Xinjiang Medical University and the People\'s Hospital of Xuancheng City admitted (09/2018-08/2021) because of bradyarrhythmia. The left atrium was modeled using the Carto3 mapping system. The ablation endpoint was the absence of a vagal response under anatomically localized and high-frequency stimulation guidance. Postoperative routine follow-up was conducted. Holter data at 3-, 6-, and 12-months were recorded.
Fifty patients (25 male, mean age 33.16 ± 7.89 years) were induced vagal response by either LSGP, LIGP, RAGP, or RIGP. The heart rate was stable at 76 bpm, SNRT 1.092s. DC, DR, HR, SDNN, RMSSD values were lower than that before ablation. AC, SSR, TH values were higher than those before ablation, mean heart rate and the slowest heart rate were significantly increased. There were significant differences in follow-up data between the preoperative and postoperative periods (all p < 0.05). All the patients were successfully ablated, and their blood pressure decreased significantly. No complications such as vascular damage, vascular embolism and pericardial effusion occurred.
Left Atrial GP ablation has good long-term clinical results and can be used as a treatment option for patients with bradyarrhythmia.