Atrioventricular synchronous leadless pacing: Micra AV.

Since the arrival of leadless pacemakers (LPs), they have become a cornerstone in remedial treatment of bradycardia and atrioventricular (AV) conduction disorders, as an alternative to transvenous pacemakers. Even though clinical trials and case reports show indisputable benefits of LP therapy, they also bring some doubts. Together with the positive results of the MARVEL trials, AV synchronization has become widely available in LPs, presenting a significant development in leadless technology. This review presents the Micra AV (MAV), describes major clinical trials, and introduces the basics of AV synchronicity obtained with the MAV and its unique programming options.

Outcomes for patients with implanted cardioverter-defibrillators admitted to the Emergency Department due to electrical shock during the pre-pandemic and COVID-19 era.

BACKGROUND: Implantable cardioverter-defibrillators (ICD)/cardiac resynchronization therapy with defibrillation (CRT-D) recipients may be susceptible to the arrhythmic effects of severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) infection. AIMS: We aimed to evaluate characteristics and outcomes of patients hospitalized for ICD/CRT-D shocks during the pandemic compared to the pre-pandemic period. METHODS: This retrospective study analyzed medical records of patients hospitalized for ICD/CRT-D shock in the pre-pandemic (January 1, 2018-December 31, 2019) and pandemic periods (March 4, 2020-March 3, 2022). Survival data were obtained on October 24, 2022. RESULTS: In total, 198 patients (average age 65.6 years) had 138 pre-pandemic and 124 pandemic visits. Of these patients, 115 were hospitalized during pre-pandemic, 108 during the pandemic, and 25 in both periods. No significant differences were noted in age, sex, number of shocks, or appropriateness of therapy between these periods. During the pandemic, during 14 hospital stays of patients with SARS-CoV-2, 8 (57.1%) received electrical shocks, compared to 12 (10.9%) with negative SARS-CoV-2 tests (P <0.001). The in-hospital mortality rate was 2 of 115 patients hospitalized during the pre-pandemic and 7 of 108 during pandemic periods (4 patients with and 3 without SARS-CoV-2 [P = 0.10]). During the follow-up, there were 66 deaths. Cox regression analysis showed that survival decreased with age and heart failure decompensation in medical history but increased with higher ejection fraction. The pandemic alone was not a survival predictor. However, SARS-CoV-2 infection, older age, and heart failure decompensation in medical history predicted worse outcomes during the pandemic period. CONCLUSIONS: The pandemic did not increase the number of hospital visits due to ICD/CRT-D discharges. SARS-CoV-2 infection predicts increased mortality in patients with ICD/CRT-D shocks.

Implantation of a Leadless Pacemaker after Incomplete Transvenous Lead Extraction in a 90-Year-Old Pacemaker-Dependent Patient.

Transluminal lead extraction (TLE) is a well-established procedure for the removal of damaged or infected pacing systems. Despite its high efficacy, the procedure is associated with significant risks, some of which may contribute to severe life-threatening complications. Herein, we present the case of a 90-year-old female who was 100% pacemaker-dependent (PM-dependent) and had ventricular lead fragmentation after the TLE procedure. In this elderly patient, after taking into account the whole clinical context-age, frailty syndrome, infection, and high peri- and postprocedural risks-we decided on MICRA VR implantation as well as leaving the remains of the ventricular lead in the right heart chambers. A Leadless pacemaker (LP) is an excellent alternative to PM-dependent individuals, in whom implantation of permanent transvenous PM is precluded due to multiple infectious and non-infectious issues.

Predictors of mortality in emergency department patients with chest pain without cardiovascular emergencies.

BACKGROUND: Chest pain is one of the most frequent symptoms in patients seeking treatment at emergency departments (ED). These patients differ according to the cause of their reported symptoms and resultant mortality. OBJECTIVES: Evaluation of the influence of hospitalization and biochemical parameters on mortality rates in patients admitted to the ED with chest pain, in whom no cardiovascular emergencies were established. MATERIAL AND METHODS: The study group consisted of 243 patients with chest pain admitted to the ED in the Wroclaw Medical University Clinical Hospital, Poland, between January 1 and March 31, 2015, in whom no specific diagnosis was made at discharge. A retrospective analysis was carried out based on medical documentation, and 60-day and 1-year survival was assessed. RESULTS: In the study group, the 60-day mortality rate was 0.8% (2 persons) while the 1-year mortality rate was 6.6% (16 persons). The stepwise multivariable logistic regression analysis revealed that 1-year mortality was related to increased level of D-dimer (odds ratio (OR) = 8.5, 95% confidence interval (95% CI) = 21.9-37.5, p < 0.005), age (OR (per year) = 1.10, 95% CI = 1.03-1.18, p < 0.03) and lower than 12 g/dL hemoglobin concentration (OR = 18.5, 95% CI = 4.2-80.4, p < 0.001). Troponin I (TNI) levels and hospitalization were not related independently to mortality when other clinical factors were considered. CONCLUSIONS: Hospitalization of patients with chest pain who were not diagnosed with cardiac emergencies is not related with better survival than of those discharged home from the ED. The 60-day mortality is very low and occurs in older patients with numerous comorbidities. In multivariate analysis, survival of the 1-year period depends on the patient's age, hemoglobin levels and D-dimer levels. Risk of death in patients admitted to the ED due to chest pain in whom the cause of the chest pain was not due to cardiovascular emergencies depends on the presence of old age and comorbidities.

Bachmann's Bundle Pacing not Only Improves Interatrial Conduction but Also Reduces the Need for Ventricular Pacing.

BACKGROUND: Patients treated for sick sinus syndrome may have interatrial conduction disorder leading to atrial fibrillation. OBJECTIVES: This study was aimed to assess the influence of the atrial pacing site on interatrial and atrioventricular conduction as well as the percentage of ventricular pacing in patients with sick sinus syndrome implanted with atrioventricular pacemaker. MATERIAL AND METHODS: The study population: 96 patients (58 females, 38 males) aged 74.1 ± 11.8 years were divided in two groups: Group 1 (n = 44) with right atrial appendage pacing and group 2 (n = 52) with Bachmann's area pacing. We assessed the differences in atrioventricular conduction in sinus rhythm and atrial 60 and 90 bpm pacing, P-wave duration and percentage of ventricular pacing. RESULTS: No differences in baseline P-wave duration in sinus rhythm between the groups (102.4 ± 17 ms vs. 104.1 ± 26 ms, p = ns.) were noted. Atrial pacing 60 bpm resulted in longer P-wave in group 1 vs. group 2 (138.3 ± 21 vs. 106.1 ± 15 ms, p < 0.01). The differences between atrioventricular conduction time during sinus rhythm and atrial pacing at 60 and 90 bpm were significantly longer in patients with right atrial appendage vs. Bachmann's pacing (44.1 ± 17 vs. 9.2 ± 7 ms p < 0.01 and 69.2 ± 31 vs. 21.4 ± 12 ms p < 0.05, respectively). The percentage of ventricular pacing was higher in group 1 (21 vs. 4%, p < 0.01). CONCLUSIONS: Bachmann's bundle pacing decreases interatrial and atrioventricular conduction delay. Moreover, the frequency-dependent atrioventricular conduction lengthening is much less pronounced during Bachmann's bundle pacing. Right atrial appendage pacing in sick sinus syndrome patients promotes a higher percentage of ventricular pacing.