Reactive granulopoiesis depends on T-cell production of IL-17A and neutropenia-associated alteration of gut microbiota.

Granulopoiesis in the bone marrow adjusts cellular output as demand for neutrophils changes. Reactive granulopoiesis is induced by profound neutropenia, but its mechanism remains to be clarified. We herein explored its mechanisms using mouse models of syngeneic hematopoietic stem cell transplantation (SCT) and 5-fluorouracil-induced neutropenia. After SCT, T cell production of IL-17A was up-regulated. Neutrophil recovery was significantly delayed in IL-17A-deficient or T cell-deficient RAG1-/- mice, and adoptive transfer of wild-type (WT) T cells facilitated neutrophil engraftment. Gut decontamination with oral antibiotics suppressed T cell production of IL-17A and impaired neutrophil recovery. Transplantation of fecal microbiota collected from neutropenic, not naive, mice promoted neutrophil recovery in these mice, suggesting that neutropenia-associated microbiota had a potential to stimulate reactive granulopoiesis. Our study uncovered a cross talk between gut microbiota and neutropenia after SCT and chemotherapy.

Iatrogenic vertebral artery injury during catheter ablation treated using coil embolization.

The internal jugular vein (IJV) is occasionally used for blood access during catheter ablation. Additionally, accidental injury of the vertebral artery during an IJV puncture is a rare complication that can result in catastrophic events, such as death. However, vascular access complications cannot be completely prevented despite the introduction of ultrasound-guided punctures. Here, we present a case of a patient with symptomatic paroxysmal atrial fibrillation that required catheter ablation.

The relationship between spino-pelvic-hip mobility and quality of life before and after total hip arthroplasty.

INTRODUCTION: Total hip arthroplasty (THA) can significantly improve quality of life (QOL) in patients with hip osteoarthritis. A relationship exists between activity levels and postoperative QOL, but its determinants are not well known. The aim of this work was to investigate the relationship between hip, pelvis and lumbar spine mobility and alignment before and after THA with QOL. MATERIAL AND METHODS: Consecutive patients with hip arthrosis and an indication for THA were included prospectively between July 2019 and December 2020, and they underwent lateral radiographs in free-standing, extension, relaxed- and flexed-seated position. Spinopelvic and hip parameters were measured, as well as their changes between positions to assess hip, pelvis and lumbar spine mobility. Patients were also administered QOL questionnaires. Data were collected preoperatively and 6 and 12 months postoperatively. RESULTS: Seventy patients were included; QOL significantly increased 6 months after THA (from 18 [10; 27] to 61 [48; 72], p < 0.001). QOL further increased by 10 points or more after 6 months in 18% of patients, while it decreased in 16%. The latter showed higher pelvic range of motion (between flexion and extension) than the former. CONCLUSIONS: This study confirmed that QOL is significantly improved by THA, and that spinopelvic alignment and function can play a role. Future work should elucidate how to better predict postoperative QOL from preoperative patient characteristics to improve patient treatment and establish early postoperative physical therapy for patients who could benefit from postoperative improvement of activity-related QOL.

Prevalence of glucose metabolism disorders and its association with left atrial remodelling before and after catheter ablation in patients with atrial fibrillation.

AIMS: To investigate the exact prevalence of glucose metabolism disorders, and their impact on left atrial (LA) remodelling and reversibility in patients with atrial fibrillation (AF). METHODS AND RESULTS: We examined 204 consecutive patients with AF who underwent their first catheter ablation (CA). Oral glucose tolerance test was used to evaluate glucose metabolism disorders in 157 patients without known diabetes mellitus (DM). Echocardiography was performed before and 6 months after CA. Oral glucose tolerance test identified abnormal glucose metabolism in 86 patients [11 with newly diagnosed DM, 74 with impaired glucose tolerance (IGT) and 1 with impaired fasting glucose (IFG)]. Ultimately, 65.2% of patients had abnormal glucose metabolism. Diabetes mellitus group had the worst LA reservoir strain and LA stiffness (both P < 0.05), while there was no significant difference in baseline LA parameters between normal glucose tolerance (NGT) group and IGT/IFG group. The prevalence of LA reverse remodelling (≥15% decrease in the LA volume index at 6 months after CA) was significantly higher in NGT group compared with IGT/IFG and DM group (64.1 vs. 38.6 vs. 41.5%, P = 0.006). Both DM and IFG/IGT carry a significant risk of lack of LA reverse remodelling independent of baseline LA size and AF recurrence. CONCLUSION: Approximately 65% of patients with AF who underwent their first CA had abnormal glucose metabolism. Patients with DM had significantly impaired LA function compared with non-DM patients. Impaired glucose tolerance/IFG as well as DM carries significant risk of unfavourable LA reverse remodelling. Our observations may provide valuable information regarding the mechanisms and therapeutic strategies of glucose metabolism-related AF.

CT-based analysis of sagittal and coronal lumbar endplate morphology: multivariate analysis of factors associated with endplate depth.

PURPOSE: Lumbar endplate morphology varies in individuals; thus, custom-made implants are sometimes more useful than standardized implants. This study aimed to analyze endplate morphology and factors associated with endplate depth using computed tomography (CT) in a non-symptomatic population. METHODS: In total, 118 lumbar CT images of non-symptomatic individuals without severe degenerative change (aged 20-79 years) were retrospectively reviewed. The following radiographic parameters were measured in each lumbar vertebral segment (T12-S1) to determine endplate depth: superior/inferior endplate depth in the midsagittal and midcoronal planes, disk angle, and height. The relationship between baseline demographics (age, sex, body mass index [BMI], Hounsfield unit of the L1 vertebral body, and pelvic incidence [PI]) and endplate depth was analyzed. RESULTS: Toward the caudal level, the superior endplate depth increased, sagittal inferior depth decreased, and coronal inferior depth increased. Multivariate analysis revealed that endplate depth was significantly associated with age (p < 0.001), while inferior endplate depth was associated with PI (p = 0.01). Superior endplate depth was associated with female sex (sagittal: p = 0.005, coronal: p = 0.002). Endplate depth, except for the inferior coronal region, was associated with low BMI (sagittal superior: p = 0.005; coronal superior and sagittal inferior: p = 0.02). CONCLUSION: Endplate depths tend to be larger toward the caudal level, particularly in the superior endplate. Surgeons should thoroughly evaluate the preoperative CT image because various endplate morphologies require attention to cage shape when performing lumbar interbody fusion, especially in patients who are older, are female, have low BMI, and have large PI. LEVEL OF EVIDENCE I: Diagnostic: individual cross-sectional studies with consistently applied reference standard and blinding.

Cerebral swelling caused by deep venous thrombosis immediately after cranioplasty.

Recently, different groups have reported a rare, unexplained complication of sudden death with massive cerebral oedema immediately after cranioplasty.Case presentation: A 34-year-old woman underwent decompressive hemicraniectomy after traumatic brain injury. She was reportedly on oral contraceptives. She developed massive cerebral swelling immediately after an uneventful cranioplasty. After surgery, her pupils became fixed and dilated, and brain MRI revealed massive brain oedema. Magnetic resonance venography displayed occlusion in the deep venous sinus. The oedema was believed to be caused by venous sinus thrombosis. The patient's family declined to avail any surgical and medical treatment, and the patient died on the second postoperative day.Conclusions: Fatal massive cerebral oedema is an uncommon complication after cranioplasty in patients who had previously undergone decompressive craniectomy. Our patient was using oral contraceptives and was thus susceptible to the development of venous sinus thrombosis. Neurosurgeons must be aware of the complications associated with venous sinus thrombosis and discuss it with the patients and their families.

Sagittal alignment in patients with flexion contracture of the hip before and after total hip arthroplasty.

INTRODUCTION: In hip osteoarthritis, hip flexion contracture can severely alter the patient's alignment, and, therefore, affect the patient's quality of life (QOL). Hip contracture is not well-studied, partly because of the difficulties of its diagnosis. The aim of this study was to propose a quantitative definition of hip flexion contracture, and to analyse sagittal alignment in these patients compared to non-contracture ones, before and 12 months after total hip arthroplasty (THA). MATERIALS AND METHODS: Consecutive patients with hip arthrosis and an indication for THA were included (N = 123). Sagittal full-body radiographs were acquired in free standing position and in extension. QOL questionnaires were administered before and after surgery. Spinopelvic parameters were measured, including the pelvic-femur angle (PFA). Patients with low pelvic incidence (< 45°) were included in the hip contracture group if PFA > 5°, or PFA > -5° when pelvic incidence ≥ 45°. RESULTS: 29% of patients were in the hip flexion contracture group, and they showed lower pelvic tilt than the no-contracture group (p < 0.001), larger lumbar lordosis (LL) and smaller PI-LL (p < 0.001), as well as a forward position of the head. 16% of patients still had hip contracture 12-months postop. Contracture patients showed higher QOL scores after surgery. CONCLUSIONS: The proposed method to diagnose hip contracture group allowed to define a group of patients who showed a specific pattern of sagittal spinopelvic alignment. These patients improved their alignment and quality of life postoperatively, but their hip mobility was not always restored. Diagnosing these patients is a first step toward the development of more specific surgical approaches, aiming to improve their surgical outcome.

Hip Function Was Not Associated with the Incidence of Preoperative Deep Vein Thrombosis in Patients Undergoing Primary Total Hip Arthroplasty.

The prevalence of preoperative deep vein thrombosis (DVT) has been reported to be relatively high in patients undergoing total hip arthroplasty. We investigated the prevalence of DVT, the association between hip function and preoperative DVT, and the effect of a history of surgery in patients who underwent primary total hip arthroplasty. We retrospectively analyzed the cases of the patients who underwent primary total hip arthroplasty between April 2013 and February 2020 at our institution. We evaluated the prevalence of preoperative DVT based on the results of the patients' ultrasound screening. We performed univariate and multivariate analyses to investigate the association between the incidence of DVT and patient factors including age, sex, hip function, medical histories, and American Society of Anesthesiologists Physical Status classification. We analyzed 451 patients (494 hips). The prevalence of DVT was 14.2% (64 patients). The multivariate analysis demonstrated that increased age was an independent significant risk factor for DVT. The prevalence of preoperative DVT was relatively high among patients who underwent primary total hip arthroplasty. Preoperative DVT tended to be more prevalent in older patients. Hip function was not associated with the incidence of DVT.

Prediction of Atrial Fibrillation Being Asymptomatic at First Onset by Cardiac Pacing.

Asymptomatic or silent atrial fibrillation (AF) has long been a clinical problem due to the incidence of ischemic stroke. A method is needed to predict the development of silent AF before the occurrence of ischemic stroke. This study was focused on the symptoms of AF, especially palpitation, in pacemaker patients. We assessed the hypothesis that absence of palpitation during rapid ventricular pacing could be a predictor of future onset AF being asymptomatic.In this study, we assessed the presence of symptoms during RV pacing and AF symptoms on 145 pacemaker patients at the outpatient clinic by VVI pacing at 120 ppm. The relationship between symptoms during RV pacing and symptom during AF was assessed. The predictive value of absence of symptom during RV pacing on AF being asymptomatic was assessed.Of 145 patients, 74 had previous AF episode. Among the AF patients, absence of symptom during VVI pacing was associated with AF being asymptomatic.Of 145 patients, 71 had no previous AF events. There were 14 patients who had new-onset AF or atrial flutter (AFL) after the device implantation. Four of the 14 patients (28.6%) were symptomatic during first AF/AFL episode, and 10 (71.4%) were asymptomatic during first-onset AF. All ten patients who were asymptomatic during cardiac pacing test were asymptomatic during their initial episodes of AF as well.This study showed that absence of symptoms during rapid ventricular pacing was associated with first-onset AF being asymptomatic.

Pseudo-elevation of conduction system pacing threshold through parallel connection of an intracardiac electrogram recording system.

Parallel connection of an electrophysiology recording system (EP system) to equipment for conduction system pacing (CSP) has been widely used for fine monitoring of intracardiac electrograms and pacing evaluation. We experienced a case showing unexpected pacing threshold exacerbation under specific conditions when the EP system was connected in parallel. We evaluated the underlying mechanism using an ex vivo model. An ex vivo pacing and intracardiac electrogram monitoring model was generated using an oscilloscope, pacing system analyzer (PSA), EP system, and simulated heart. The discrepancy between expected output at the PSA and the actual measured output value at the simulated heart was measured under various conditions and using various combinations of pacing equipment. Parallel connection of the EP system was associated with reduced electrical output from the PSA as recorded at the simulated heart. The unexpected adverse effects were particularly noticeable when using an RMC-5000 EP system with the pacing function on. The trouble is completely resolved by simply turning off the pacing function of the system. There is a possibility that the EP system might increase the pacing threshold in CSP when the PSA and EP system is are deployed in parallel. The issue may provoke pseudo failure of CSP due to the high pacing threshold. When the RMC-5000 is used for conduction system pacing in parallel with a PSA for the pacing test, the pacing function of RMC-5000 should be turned off.

Sacroiliac joint degeneration is common in patients with end-stage hip osteoarthritis secondary to unilateral developmental dysplasia of the hip: Factors associated with its severity and laterality.

BACKGROUND: The etiology of sacroiliac joint (SIJ) degeneration has not been fully elucidated, and there has been almost no report on the relevance between SIJ degeneration and hip osteoarthritis secondary to developmental dysplasia of the hip (DDH). We investigated factors associated with SIJ degeneration, specifically its laterality in patients with end-stage hip osteoarthritis secondary to unilateral DDH. METHODS: We included 152 patients with end-stage unilateral hip osteoarthritis secondary to DDH who underwent primary THA between January 2008 and November 2015. SIJ degeneration was classified (type 0, no degenerative change, to type 3, ankyloses) using preoperative axial computed tomography. SIJ degeneration of the DDH (shorter leg) and contralateral (longer leg) sides was compared; differences in patient demographics and radiological parameters between SIJ degeneration of type 0 or 1 versus type 2 or 3 for the shorter and longer leg sides were analyzed. RESULTS: SIJ on the longer leg side showed more degenerative changes (p < 0.001). Substantial SIJ degeneration or ankylosis (type 2 or 3) was observed on 62.5% of longer leg sides and 33.6% of shorter leg sides. Factors significantly associated with SIJ degeneration severity were percent hip subluxation and leg length discrepancy for the longer leg side and body weight and body mass index (BMI) for the shorter leg side. Patients with worse degeneration on the shorter leg side (9.9%) had significantly larger BMI and longer sagittal vertical axis, whereas patients with worse degeneration on the longer leg side (46.7%) had significantly longer leg length discrepancy. CONCLUSION: Severe SIJ degeneration was common in patients with end-stage hip osteoarthritis secondary to unilateral DDH. Patients with worse SIJ degeneration on the longer leg side had more hip subluxation, whereas patients with worse SIJ degeneration on the shorter leg (DDH) side tended to have sagittal spinal imbalance and greater body weight with larger BMI.

Disease progression-associated alterations in fecal metabolites in SAMP1/YitFc mice, a Crohn's disease model.

INTRODUCTION: Crohn's disease (CD) is a chronic, relapsing inflammatory bowel disease affecting the gastrointestinal tract. Although its precise etiology has not been fully elucidated, an imbalance of the intestinal microbiota has been known to play a role in CD. Fecal metabolites derived from microbiota may be related to the onset and progression of CD OBJECTIVES: This study aimed to clarify the transition of gut microbiota and fecal metabolites associated with disease progression using SAMP1/YitFc mice, a model of spontaneous CD METHODS: The ileum tissues isolated from SAMP1/YitFc mice at different ages were stained with hematoxylin-eosin for histologic characterization with CD progression. Feces from control, Institute of Cancer Research (ICR; n = 6), and SAMP1/YitFc (n = 8) mice at different ages were subjected to microbial analysis and 1H nuclear magnetic resonance (NMR) analysis to investigate fluctuations in gut microbiota and fecal metabolites with CD progression RESULTS: Relative abundance of the Lachnospiraceae, Ruminococcaceae, Bacteroidaceae, and Bacteroidales S24-7 at family-level gut microbiota and fecal metabolites, such as short-chain fatty acids, lactate, glucose, xylose, and choline, dramatically fluctuated with histologic progression of intestinal inflammation in SAMP1/YitFc mice. Unlike the other metabolites, fecal taurine concentration in SAMP1/YitFc mice was higher than ICR mice regardless of age CONCLUSION: The fecal metabolites showing characteristic fluctuations may help to understand the inflammatory mechanism associated with CD, and might be utilized as potential biomarkers in predicting CD pathology.

Cervical spinal computed tomography utilizing model-based iterative reconstruction reduces radiation to an equivalent of three cervical X-rays.

PURPOSE: To evaluate radiation dose and image quality of cervical spinal computed tomography scanned with low-radiation dose (LD-CT) utilizing model-based iterative reconstruction (MBIR). METHODS: We retrospectively examined 14 patients (65.5 ± 13.9 years) who underwent both standard-radiation-dose CT (SD-CT) reconstructed with hybrid iterative reconstruction and LD-CT of cervical spine. The radiation dose, objective image quality indicator, which includes signal-to-noise and contrast-to-noise, and subjective image quality score of the anatomical landmarks in the SD-CT and LD-CT were statistically compared. In addition, the measurement errors of the length of C3 vertebrae (height, anteroposterior length, inner and outer pedicle diameters) between SD-CT and LD-CT were analyzed. RESULTS: Radiation dose of LD-CT was reduced to one-sixth of the dose of SD-CT. The objective image quality indicator of LD-CT was significantly better than that of SD-CT. The subjective image quality of LD-CT was relatively worse than that of SD-CT but generally graded as clinically accepted or higher. There was no remarkable difference between SD-CT and LD-CT in the measurement value of height and anteroposterior length. Inner pedicle diameter was significantly (0.21 ± 0.13 mm) smaller, and outer pedicle diameter was (0.24 ± 0.14 mm) larger on LD-CT than on SD-CT. CONCLUSION: Cervical spinal LD-CT that utilized MBIR enabled radical decrease in radiation dose and provided sufficient image quality for clinical use. This scanning protocol can be a good alternative for protecting patients from exposure to unnecessary radiation, especially when a patient requires multiple CT scans.

Developmental potential of somatic and germ cells of hybrids between Carassius auratus females and Hemigrammocypris rasborella males.

The cause of hybrid sterility and inviability has not been analyzed in the fin-fish hybrid, although large numbers of hybridizations have been carried out. In this study, we produced allo-diploid hybrids by cross-fertilization between female goldfish (Carassius auratus) and male golden venus chub (Hemigrammocypris rasborella). Inviability of these hybrids was due to breakage of the enveloping layer during epiboly or due to malformation with serious cardiac oedema around the hatching stage. Spontaneous allo-triploid hybrids with two sets of the goldfish genome and one set of the golden venus chub genome developed normally and survived beyond the feeding stage. This improved survival was confirmed by generating heat-shock-induced allo-triploid hybrids that possessed an extra goldfish genome. When inviable allo-diploid hybrid cells were transplanted into goldfish host embryos at the blastula stage, these embryos hatched normally, incorporating the allo-diploid cells. These allo-diploid hybrid cells persisted, and were genetically detected in a 6-month-old fish. In contrast, primordial germ cells taken from allo-diploid hybrids and transplanted into goldfish hosts at the blastula stage had disappeared by 10 days post-fertilization, even under chimeric conditions. In allo-triploid hybrid embryos, germ cells proliferated in the gonad, but had disappeared by 10 weeks post-fertilization. These results showed that while hybrid germ cells are inviable even in chimeric conditions, hybrid somatic cells remain viable.

Long-term outcome of cemented total hip arthroplasty with the Charnley-type femoral stem made of titanium alloy.

BACKGROUND: Total hip arthroplasty is a successful treatment for hip diseases including osteoarthritis, osteonecrosis of the femoral head, and rheumatoid arthritis. Various designs of cemented femoral stems made of stainless steel and titanium alloy have been used. Among them, Charnley-type femoral stems made of stainless steel have often been reported to have good long-term outcome. However, the long-term outcome of the Charnley-type femoral stem made of Ti alloy is yet to be reported. We conducted a retrospective study to assess the long-term outcome of cemented primary total hip arthroplasty with the Charnley-type femoral stem made of Ti alloy. METHODS: Between October 1988 and February 1997, 341 cemented primary total hip arthroplasties with the Charnley-type femoral stem made of Ti alloy were consecutively performed in our hospital. Among these, 164 patients (211 hips) who underwent this procedure were followed up for more than 12 years, and the surgical hips were analysed clinically and radiologically. The mean follow-up period was 20.6 years. Kaplan-Meier survival analyses were performed to assess femoral component survival. Factors affecting stem revision for aseptic loosening were also investigated using log-rank tests. RESULTS: In the functional assessment, the preoperative Japanese Orthopaedic Association score significantly improved from 47.2 points preoperatively to 79.0 points at the final follow-up. Eventually, 33 femoral stems were revised, of which 12 were revised for aseptic loosening. In the Kaplan-Meier survival analysis, the 20-year survival rates with stem revision for aseptic loosening and radiological stem loosening at the end points were 95.9% and 97.1%, respectively. Original diagnosis (non-osteoarthritis) was the only significant factor for aseptic loosening of the femoral stem. CONCLUSIONS: Cemented primary total hip arthroplasty with the Charnley-type femoral stem made of Ti alloy showed excellent outcomes for more than 20 years.

Deep Venous Thrombosis with Decreased Cerebral Blood Flow to the Thalamus was Completely Restored by Factor Xa Inhibitor.

BACKGROUND: Cerebral venous thrombosis is rare and an uncommon cause of stroke and has diverse etiologies and varied clinical presentations. Here, we report 2 cases of deep cerebral venous thrombosis. CASE DESCRIPTION: A 64-year-old woman presented with cerebral venous thrombosis due to a hypercoagulable state associated with ovarian tumor. On initial fluid-attenuated inversion recovery and diffusion-weighted imaging, there was a diffuse high-intensity lesion in the bilateral thalamus. Computed tomography angiography showed occlusion of the straight sinus, vein of Galen, and internal cerebral vein. Single-photon emission computed tomography showed decreased cerebral blood flow in the bilateral thalamus. After 3 weeks of factor Xa inhibitor therapy, the patient's consciousness gradually improved and eventually became clear enough to leave the hospital. She had no neurological deficit. Another patient was a 47-year-old man who presented with splitting headache and drowsiness. Magnetic resonance venography confirmed deep thrombosis of the vein of Galen. He completely recovered after 4 weeks of factor Xa inhibitor therapy. CONCLUSIONS: This study reports on 2 rare cases of decreased cerebral blood flow in the bilateral thalamus on single-photon emission computed tomography, which improved following the administration of factor Xa inhibitor.

Periprocedural Complications in Patients Undergoing Catheter Ablation of Atrial Fibrillation Without Discontinuation of a Vitamin K Antagonist and Direct Oral Anticoagulants.

BACKGROUND: Periprocedural anticoagulation is important in catheter ablation (CA) of atrial fibrillation (AF) and there is increasing evidence that uninterrupted vitamin K antagonist (VKA) therapy is superior to interrupted anticoagulation strategies. Since the emergence of direct oral anticoagulants (DOACs), numerous studies have shown promising results for their use in uninterrupted strategies. However, further studies are needed to further define the efficacy and safety of performing AF ablation with uninterrupted factor XA inhibitors or direct thrombin inhibitors.Methods and Results:We have performed CA of AF without discontinuation of either VKA or DOAC therapy since April 2014. A total of 376 patients with AF underwent CA including pulmonary vein isolation. All of the patients were divided into 2 groups (uninterrupted VKA or uninterrupted DOACs). Anticoagulation with DOACs was associated with fewer complications than uninterrupted VKA therapy (P=0.04). There were significant differences between groups in the rates of congestive heart failure, left ventricular ejection fraction, body weight, and estimated glomerular filtration rate and of the CHADS2, CHA2DS2-VASc and HAS-BLED scores. Therefore, we also analyzed the results using the propensity score-matching method. We found no significant difference in periprocedural complications between uninterrupted VKA or DOACs therapy (P=0.65). CONCLUSIONS: CA of AF without discontinuation of DOACs is not inferior to CA without discontinuation of a VKA, with regard to ischemic or hemorrhagic complications.

A Case of a Cardiac Resynchronization Therapy-Defibrillator Exhibiting a Lower and Alternately Variable Basic Rate.

A cardiac resynchronization therapy defibrillator (CRT-D) (Medtronic Inc. Protecta XT) was implanted in a 67-year-old man who had cardiac sarcoidosis with extremely low cardiac function. He had ventricular tachycardia which was controlled by catheter ablation, medication and pacing. The programmed mode was DDI, lower rate was 90 beats/minute, paced AV delay was 150 ms, and the noncompetitive atrial pacing (NCAP) function was programmed as 300 ms.After his admission for pneumonia and heart failure, we changed his DDI mode to a DDD mode because he had atrial tachycardia, which led to inadequate bi-ventricular pacing. After a while, there were cycle lengths which were longer than his device setting and alternately varied. We were able to avoid this phenomenon with AV delay of 120 ms and NCAP of 200 ms.NCAP is an algorithm which creates a gap above a certain period after the detection of an atrial signal during the postventricular atrial refractory period of the pacemaker. This is to prevent atrial tachycardia and repetitive non-reentrant ventriculoatrial (VA) synchrony in the presence of retrograde VA conduction. But in this case, NCAP algorithm induced much lower rate than the programmed basic lower rate. This situation produced some arrhythmias and exacerbated symptoms of heart failure. This had to be paid attention to, especially when the device was programmed at high basic heart rate.