Atrial fibrillation induced by inappropriate reactive antitachycardia pacing due to far field R wave oversensing: A case report.

An 89-year-old man with an intermittent 2:1 second-degree atrioventricular block received a permanent pacemaker (Medtronic Azure XT DR; Medtronic Inc., Minneapolis, MN, USA). Reactive antitachycardia pacing (ATP) was engaged in all transmissions 3 weeks later. Intracardiac recordings revealed a far-field R wave (FFRW) oversensing, occurring between atrial waves and premature atrial contractions. This event triggered the delivery of reactive ATP, which induced atrial fibrillation. A 79-year-old man underwent permanent pacemaker implantation for an intermittent complete atrioventricular block. One month after implantation, reactive ATP was initiated. The atrial electrogram of intracardiac recordings revealed one being a spontaneous P wave and the other an oversensed R wave. The criterion for an atrial tachycardia was fulfilled, and the device initiated reactive ATP. As a result, atrial fibrillation was induced by inappropriate reactive ATP. It was difficult to completely avoid inappropriate reactive ATP. Finally, we discontinued reactive ATP. The two cases presented in this study demonstrate the possibility of inappropriate reactive ATP due to FFRW oversensing, with the inappropriate reactive ATP inducing atrial fibrillation. All patients treated with reactive ATP should be carefully assessed for the presence of FFRW oversensing during pacemaker implantation and during the follow-up period. Learning objective: We present two cases of inappropriate reactive ATP caused by far-field R-wave oversensing. Inappropriate reactive ATP has not been previously reported. Therefore, we suggest that all patients provided with a DDD pacemaker should be carefully assessed for the presence of FFRW oversensing during pacemaker implantation and during the follow-up period. Remote monitoring enables very early detection of inappropriate reactive ATP delivery for rapid implementation of preventive measures.

Demographic Trends and Changes in the Pre- and In-Hospital Medical Management of Acute Myocardial Infarction During the First 12 Months of the COVID-19 Pandemic in Mie Prefecture　- Report From the Mie ACS Registry.

Background: Even though hospital admissions for acute myocardial infarction (AMI) decreased globally during the COVID-19 pandemic in early 2020, limited information is available on subsequent demographic trends in the number of cases and management of AMI through the first 12 months of the COVID-19 pandemic. Methods and Results: We assessed demographic trends, patient characteristics, and AMI outcomes (n=730) during the first 12 months of the COVID-19 pandemic and compared them with corresponding months during the control period (February 2016-January 2020; n=2,742) using data from the Mie ACS Registry. Although a 25.8% reduction in hospitalizations for AMI was observed in the 3 months following the declaration of a state of emergency (47.7 vs. 64.3/month; P=0.002), the total number of AMI patients was similar between the 12-month COVID-19 and control periods (60.8 vs. 57.2/month; P=0.58). The number of patients requiring direct ambulance transport was lower in the first half of the COVID-19 than control period (44.4% vs. 51.5; P=0.028). In-hospital mortality was higher in the second half of the COVID-19 than control period (8.9% vs. 5.8%; P=0.032). Conclusions: Through the first 12 months of the COVID-19 pandemic, the number of AMI cases was similar to that in previous years. The COVID-19 pandemic changed the behavior of AMI patients and both pre- and in-hospital medical management, which significantly affected the severity and prognosis of AMI.

Endovascular Treatment for Lower-extremity Arterial Thrombosis in a Patient with Congenital Afibrinogenemia and a History of Bleeding Complications.

Congenital afibrinogenemia is a rare autosomal recessive blood disorder that accompanies thrombotic complications and is associated with bleeding tendency. The management of these opposing complications remains a challenge. Endovascular treatment (EVT) for peripheral arterial thrombosis has not been described in previous studies. A 57-year-old man with congenital afibrinogenemia developed back pain and left lower leg pain. The cause of the pain was confirmed to be renal infarction and lower extremity arterial thrombosis by Doppler ultrasound and contrast-enhanced computed tomography. He was treated with EVT for the lower extremity arterial thrombosis, leading to an excellent short-term improvement without bleeding.

Predictors of post-extubation stridor in patients on mechanical ventilation: a prospective observational study.

The cuff leak test (CLT) has been widely accepted as a simple and noninvasive method for predicting post-extubation stridor (PES). However, its accuracy and clinical impact remain uncertain. We aimed to evaluate the reliability of CLT and to assess the impact of pre-extubation variables on the incidence of PES. A prospective observational study was performed on adult critically ill patients who required mechanical ventilation for more than 24 h. Patients were extubated after the successful spontaneous breathing trial, and CLT was conducted before extubation. Of the 191 patients studied, 26 (13.6%) were deemed positive through CLT. PES developed in 19 patients (9.9%) and resulted in a higher reintubation rate (8.1% vs. 52.6%, p < 0.001) and longer intensive care unit stay (8 [4.5-14] vs. 12 [8-30.5] days, p = 0.01) than patients without PES. The incidence of PES and post-extubation outcomes were similar in patients with both positive and negative CLT results. Compared with patients without PES, patients with PES had longer durations of endotracheal intubation and required endotracheal suctioning more frequently during the 24-h period prior to extubation. After adjusting for confounding factors, frequent endotracheal suctioning more than 15 times per day was associated with an adjusted odds ratio of 2.97 (95% confidence interval, 1.01-8.77) for PES. In conclusion, frequent endotracheal suctioning before extubation was a significant PES predictor in critically ill patients. Further investigations of its impact on the incidence of PES and patient outcomes are warranted.

Pathological Q-Waves With Coronary Artery Spasm.

This case highlights the diagnostic challenge associated with myocarditis, especially when accompanied by coronary spasm. Any coronary spasm with hemodynamic instability and/or an inexplicable widespread electrocardiogram should alert the clinician to the possibility of fulminant myocarditis and the necessity of endomyocardial biopsy for treatment decisions. (Level of Difficulty: Beginner.).

Adsorption and desorption behaviors of cetylpyridinium chloride on hydroxyapatite nanoparticles with different morphologies.

Application of hydroxyapatite (HAp) nanoparticles to repair damaged enamel has attracted recent attention. In this study, HAp nanoparticles with various morphologies (spherical, short-rod, long-rod and fiber morphologies) were synthesized via chemical precipitation methods without the addition of template molecules, and the adsorption/desorption behaviors of a cationic antibacterial agent, cetylpyridinium chloride (CPC), on the HAp nanoparticles were evaluated. The adsorption of CPC on each HAp nanoparticle showed Langmuir-type adsorption, and the short-rod/long-rod HAp nanoparticles showed thermodynamically more stable adsorption of CPC than that with the spherical/fiber HAp nanoparticles. The desorption rate of CPC from the short-rod/long-rod HAp nanoparticles was slower than that of the spherical/fiber HAp nanoparticles. The HAp nanoparticles with different CPC release profiles presented here have potential applications as nanoparticulate enamel repair agents with antibacterial properties.

Perioperative fluid balance affects staging of acute kidney injury in postsurgical patients: a retrospective case-control study.

BACKGROUND: Although Acute Kidney Injury Network (AKIN) staging is widely used, it has been suggested that classification using serum creatinine levels, which fluctuate because of fluid balance, is not always appropriate for acute kidney injury (AKI) detection. We hypothesized that some patients are misdiagnosed as having no AKI due to dilution resulting from intraoperative infusion, and have worse outcomes than typical patients with no AKI. METHODS: We retrospectively selected patients who did not fulfill the AKI criteria from those who underwent cardiac surgery and remained in an intensive care unit (ICU) for ≥7 days. The patients were divided into two groups: those with AKI (AKI group) and those without AKI (no-AKI group), classified using serum creatinine levels adjusted for fluid balance during the perioperative period. We compared the characteristics and outcomes of the two groups. RESULTS: After adjustment for serum creatinine, 7 of 26 patients were categorized as having AKI. The AKI group had significantly fewer ventilator-free days during a 28-day period and significantly longer ICU stays than the no-AKI group (5.86 ± 10.0 days vs. 15.6 ± 9.71 days, respectively, P = 0.050; 36.4 ± 20.6 days vs. 14.9 ± 10.7 days, respectively, P = 0.033). CONCLUSION: Adjustment of creatinine level for perioperative fluid balance could improve the accuracy of AKI diagnosis after cardiac surgery.

Sol-gel synthesis of low-dimensional silica within coordination nanochannels.

Sol-gel condensation of tetramethoxysilane (TMOS) inside the channels of a coordination pillared layer structure [Cu2(pzdc)2(dpe)]n (1a; pzdc = pyrazine-2,3-dicarboxylate, dpe = 1,2-di(4-pyridyl)ethylene) produced subnanosized silica dispersed within the host framework. In this system, the growth of silica is effectively constrained, and the resultant silica shows a drastic decrease of its crystallization temperature because of its minute size.

[Anesthesia for a woman with triplet pregnancy presenting with acute abdomen after the recent epidural blood patch].

We report a case of primipara with triplet pregnancy who underwent combined spinal and epidural anesthesia 10 weeks after epidural blood patch. At 15 weeks of gestation, a woman with triplet gestation underwent Shirodkar operation under spinal anesthesia and subsequent epidural blood patch as a treatment of post-dural puncture headache. At 26 weeks she presented with acute abdomen and laparotomy was scheduled. Spinal anesthesia was selected with an epidural catheter inserted in case of prolonged operation and for postoperative pain control. The placement of an epidural catheter was without problem. Laparotomy revealed right paraovarian cyst torsion and the right salpingo-paraoophocystectomy was performed. Patient-controlled analgesia with epidural bupivacaine and fentanyl was effectively continued for two days. Postoperative course was uneventful and the triplets were delivered by cesarean section at 35 weeks.