Circulating intermediate CD14++CD16+monocytes are increased in patients with atrial fibrillation and reflect the functional remodelling of the left atrium.

AIMS: A recent large clinical study demonstrated the association between intermediate CD14++CD16+monocytes and cardiovascular events. However, whether that monocyte subset contributes to the pathogenesis of atrial fibrillation (AF) has not been clarified. We compared the circulating monocyte subsets in AF patients and healthy people, and investigated the possible role of intermediate CD14++CD16+monocytes in the pathophysiology of AF. METHODS AND RESULTS: This case-control study included 44 consecutive AF patients without systemic diseases referred for catheter ablation at our hospital, and 40 healthy controls. Patients with systemic diseases, including structural heart disease, hepatic or renal dysfunction, collagen disease, malignancy, and inflammation were excluded. Monocyte subset analyses were performed (three distinct human monocyte subsets: classical CD14++CD16-, intermediate CD14++CD16+, and non-classical CD14+CD16++monocytes). We compared the monocyte subsets and evaluated the correlation with other clinical findings. A total of 60 participants (30 AF patients and 30 controls as an age-matched group) were included after excluding 14 AF patients due to inflammation. Atrial fibrillation patients had a higher proportion of circulating intermediate CD14++CD16+monocytes than the controls (17.0 ± 9.6 vs. 7.5 ± 4.1%, P < 0.001). A multivariable logistic regression analysis demonstrated that only the proportion of intermediate CD14++CD16+monocytes (odds ratio: 1.316; 95% confidence interval: 1.095-1.582, P = 0.003) was independently associated with the presence of AF. Intermediate CD14++CD16+monocytes were negatively correlated with the left atrial appendage flow during sinus rhythm (r= -0.679, P = 0.003) and positively with the brain natriuretic peptide (r = 0.439, P = 0.015). CONCLUSION: Intermediate CD14++CD16+monocytes might be closely related to the pathogenesis of AF and reflect functional remodelling of the left atrium.

The Relationship Between Cardiac Vulnerability and Restitution Properties of the Ventricular Activation Recovery Interval.

INTRODUCTION: The restitution of the action potential duration (APD) is an important contributor to ventricular fibrillation (VF) initiation by a single critically timed ectopic beat. We hypothesized that a steep slope of the activation recovery interval restitution curve was related to the upper limit of vulnerability (ULV). METHODS AND RESULTS: Fifty-four consecutive patients with implantable cardioverter defibrillators (ICDs) implanted between April 2012 and July 2013 were included. At the implantation, pacing from the right ventricular (RV) coil to an indifferent electrode inserted in the ICD pocket was performed, and the unipolar electrograms from the RV coil were simultaneously recorded. We assessed the standard restitution by introducing extra-stimuli, while measuring the activation recovery interval (ARI). Our protocol for the vulnerability test consisted of delivering three 15 J shocks on the T-peak and within ±20 milliseconds of it. If VF was not induced by that procedure, a ULV of ≤15 J was defined. The relationship between the ULV and maximum slope of the restitution curve was analyzed. A restitution curve could finally be obtained in a total of 40 patients. The background characteristics were similar between the two groups. The maximum slope of the restitution curve was steeper in the ULV > 15 J group than ULV ≤ 15 J group (1.55 ± 0.45 vs. 0.91 ± 0.64, P < 0.05). A maximum slope exceeding 1.0 was the optimal point for discriminating patients with a ULV > 15 J from a ULV ≤ 15 J (sensitivity 61.5% and specificity 96.3%). CONCLUSION: The maximum slope of the restitution curve was significantly related to the ULV. High defibrillation threshold patients could be detected by the ARI dynamics.

Reduction in coronary microvascular resistance through cardiac resynchronization and its impact on chronic reverse remodelling of left ventricle in patients with non-ischaemic cardiomyopathy.

AIMS: Left bundle branch block (LBBB) induces mechanical dyssynchrony, thereby compromising the coronary circulation in non-ischaemic cardiomyopathy. We sought to examine the effects of cardiac resynchronization therapy (CRT) on coronary flow dynamics and left ventricular (LV) function. METHODS AND RESULTS: Twenty-two patients with non-ischaemic cardiomyopathy (New York Heart Association class, III or IV; LV ejection fraction, ≤35%; QRS duration, ≥130 ms) were enrolled. One week after implantation of the CRT device, coronary flow velocity and pressure in the left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCx) were measured invasively, before and after inducing hyperemia by adenosine triphosphate administration, with two programming modes: sequential atrial and biventricular pacing (BiV) and atrial pacing in patients with LBBB or sequential atrial and right ventricular pacing in patients with complete atrioventricular block (Control). We assessed hyperemic microvascular resistance (HMR, mean distal pressure divided by hyperemic average peak velocity) and the relationship between the change in HMR and mid-term LV reverse remodelling. Hyperemic microvascular resistance was lower during BiV than during Control (LAD: 1.76 ± 0.47 vs. 1.54 ± 0.45, P < 0.001; LCx: 1.92 ± 0.42 vs. 1.73 ± 0.31, P = 0.003). The CRT-induced change in HMR of the LCx correlated with the percentage change in LV ejection fraction (R = -0.598, P = 0.011) and LV end-systolic volume (R = 0.609, P = 0.010) before and 6 months after CRT. CONCLUSION: Cardiac resynchronization therapy improves coronary flow circulation by reducing microvascular resistance, which might be associated with LV reverse remodelling.

Crista Terminalis as the Anterior Pathway of Typical Atrial Flutter: Insights from Entrainment Map with 3D Intracardiac Ultrasound.

BACKGROUND: The precise location of truly active reentry circuits of typical atrial flutter (AFL) has not been well identified. The purpose of this study was to verify our hypothesis that the posterior block line is located along the posteromedial right atrium (PMRA) and the crista terminalis (CT) is the anterior pathway of AFL, with real-time intracardiac echo (ICE). METHODS: The entire right atrium (RA) three-dimensional activation and entrainment mapping were evaluated during AFL in 18 patients using CARTO sound. RESULTS: The CT was clearly visualized by ICE and the local electrograms along the CT were single potentials in all the patients. The CT was recognized as the truly active anterior pathway based on entrainment mapping in all patients. Double potentials were recorded along the PMRA. Entire RA entrainment mapping could be performed in 16 patients. The reentry circuits were separated into three passages. The first was around the tricuspid annulus (TA), the second the anterior superior vena cava (SVC; AFL waves passed between the anterior SVC and RA appendage), and the last the posterior SVC (between the posterior SVC and upper limit of the PMRA). All three of these passages were active in four, around the TA and anterior SVC in eight, around the TA and posterior SVC in three, and around only the anterior SVC in one patient. CONCLUSIONS: The CT functions as the anterior pathway of typical AFL, and the posterior block line was located along the PMRA. Dual or triple circuits were recognized in the majority of AFL patients.

Upper limit of vulnerability during defibrillator implantations predicts the occurrence of appropriate shock therapy for ventricular fibrillation.

BACKGROUND: The utility of the upper limit of vulnerability (ULV) test in patients undergoing defibrillator implantation has been reported, so the purpose of this study was to evaluate the difference in the clinical outcomes between patients with ULV ≤15 J or >15 J. METHODS AND RESULTS: A total of 165 patients receiving an implantable cardioverter-defibrillator underwent a vulnerability test. At the time of the implantation, we delivered a 15-J shock on the T-peak and ±20 ms later to cover the most vulnerable part of the cardiac cycle. The clinical outcomes were prospectively analyzed. A 15-J shock induced ventricular fibrillation (VF) in 30 patients (ULV >15 J) and did not in 135 (ULV ≤15 J). The characteristics of the 2 groups were comparable. After a mean follow-up of 757 days, Kaplan-Meier curve analysis showed that the ULV ≤15 J group experienced less VF than the ULV >15 J group (log-rank P=0.003). The occurrence of ventricular tachycardia was similar between the 2 groups (P=0.140). Furthermore, the effectiveness of ATP was comparable. After adjusting for other known predictors of shock therapy, a ULV >15 J was independently associated with the occurrence of VF (hazard ratio: 6.25; 95% confidence interval: 1.913-20.40; P<0.01). CONCLUSIONS: A high ULV value was associated with a high incidence of VF, which suggests that cardiac vulnerability to electrical shock may be linked to electrical instability.

Visualization of the antegrade fast and slow pathway inputs in patients with slow-fast atrioventricular nodal reentrant tachycardia.

INTRODUCTION: Mapping of the antegrade fast pathway (A-FP) exact sites and antegrade slow pathway (A-SP) input locations has not been well described. METHODS: In 56 patients with slow-fast atrioventricular nodal reentrant tachycardia (SF-AVNRT), pacing during sinus rhythm and entrainment pacing during SF-AVNRT were performed at various sites in the triangle of Koch and coronary sinus (CS) to identify the A-FP and A-SP inputs. User-defined three-dimensional electro-anatomical mapping of the stimulus-His potential (St-H) interval and anatomical location was performed. The A-FP input was defined as the site of the shortest St-H interval, and A-SP input as the site of the shortest St-H interval and with a postpacing-interval equal to the tachycardia cycle length. The locations of the A-FP and A-SP inputs were mapped as a ratio of the distance between the His bundle (HB) and CS orifice (CSO), and the HB-CSO axis was divided into three zones: superior-, mid-, and inferior septum. The distance between the A-SP and A-FP inputs was calculated using the distance from each input to the HB and HB-CSO axis. RESULTS: Only 30 patients were included in this study because the A-SP mapping failed in 26. The A-SP input was distributed to the superior septum in four, mid- or inferior septum in 25, and CS in one. An A-SP input which was located less than 10 mm from the A-FP input was observed in one of four patients with a superior septum A-SP. CONCLUSIONS: An A-SP input at the superior septum seemed to be a potential risk for atrioventricular nodal injury during ablation.

Discrepancy between electrical and mechanical dyssynchrony in patients with heart failure and an electrical disturbance.

BACKGROUND: Cardiac resynchronization therapy (CRT) improves the survival rates of patients with heart failure, but 30-40% of them do not respond to CRT, partially because of the position of the left ventricular (LV) lead. The relationship between the electrical and mechanical activation of the left ventricle is unknown. The aim of this study was to compare the electrical and mechanical dyssynchrony. METHODS: We inserted electrode catheters into the coronary sinus (CS) and venous branches of the CS during CRT implantations and constructed electroanatomical contact maps in 16 patients using the EnSite NavX™ system. Mechanical activation was evaluated by speckle-tracking echocardiography and the latest mechanical and electrical sites were compared. The degrees of the electrical and mechanical delays of the implanted LV lead were also compared. RESULTS: The electroanatomical maps revealed that the latest electrical sites were anterior in one, anterolateral in five, lateral in eight, and posterolateral in two. Echocardiographic imaging revealed that the latest mechanical sites were anteroseptal in two, anterior in four, lateral in five, posterior in two, and inferior in three. The latest electrical and mechanical sites matched in only three patients. The degree of the local mechanical delay for the LV lead was significantly larger in the responders than nonresponders, whereas the local electrical delay did not differ. CONCLUSION: A discrepancy between the electrical and mechanical dyssynchrony might affect an adequate LV lead positioning.

A case of cough syncope diagnosed by the Valsalva maneuver and cough induction test under invasive arterial pressure measurement.

Following the loss of consciousness during the Valsalva maneuver and cough induction test, real-time arterial pressure measurement could clarify the significant blood pressure decrease in a patient with cough syncope.

Time-dependent effect of cardiac resynchronization therapy on ventricular repolarization and ventricular arrhythmias.

AIMS: Cardiac resynchronization therapy (CRT) improves the clinical status of patients with congestive heart failure, although left ventricular epicardial pacing may increase transmural dispersion of repolarization (TDR). The aim of this study was to investigate the time-dependent effect of CRT on ventricular repolarization and ventricular arrhythmia at mid-term follow-up. METHODS AND RESULTS: The study group consisted of 84 patients treated with CRT. Twelve-lead electrocardiogram was digitally recorded and Tpeak-to-Tend interval (Tp-e) was measured at baseline, 1 week, 1 month, and 3, 6, and 12 months after device implantation. We determined the time-dependent changes in Tp-e, ventricular tachycardia and ventricular fibrillation (VT/VF) during 12 months of follow-up, in both CRT responders and non-responders. Seventeen of 84 patients (20%) had VT/VF during first year. Six of those 17 patients (35%) experienced VT/VF within 1 month of implantation and diminished over time. Tp-e decreased significantly at 6 and 12 months after implantation compared with 1 week [108 ± 14 ms at 1 week vs. 97 ± 21 ms at 6 months (P = 0.03) and 95 ± 19 ms at 12 months (P = 0.01)]. Responders demonstrated a greater time-dependent reduction of Tp-e at 6 and 12 months of CRT and had a lower rate of VT/VF compared with non-responders (log-rank test, P = 0.004). CONCLUSION: Transmural dispersion of repolarization and the number of patients with VT/VF decreased over time after CRT. Patients with reverse remodelling demonstrated a lower rate of VT/VF and a greater time-dependent reduction of TDR.

Optimal strength and number of shocks at upper limit of vulnerability testing required to predict high defibrillation threshold without inducing ventricular fibrillation.

BACKGROUND: The upper limit of vulnerability (ULV) closely correlates with the defibrillation threshold (DFT). The aim of this study was to establish the optimal protocol for using the ULV test to predict high DFT (>20 J) without inducing ventricular fibrillation (VF). METHODS AND RESULTS: The 10-J and 15-J ULV test with 3 coupling intervals (-20, 0, and +20 ms to the peak of T-wave) and the DFT test were performed in 96 patients receiving implantable cardioverter defibrillator. ULV ≤ 10 J was confirmed in 47 (49%). ULV ≤ 15 J was confirmed in 70 (77%) of 91 patients (15-J ULV test could not be done in 5). The sensitivity and negative predictive value of both ULV >10 J and >15 J for predicting high DFT were 100%. The specificity and positive predictive value of ULV >15 J were higher than those for ULV >10 J (85% vs. 55%, 43% vs. 22%, respectively). The rate of VF inducibility for confirming ULV ≤ 15 J was lower than that for ULV ≤ 10 J (23% vs. 51%, P<0.0001). On analysis of single 15-J ULV test only at the peak of T-wave, VF was not induced in 79 of 91 patients, but 4 of these had high DFT. CONCLUSIONS: The 15-J ULV test with 3 coupling intervals could correctly identify high-DFT patients and reduce the necessity for VF induction at defibrillator implantation.

Pacemaker implantation for persistent sinus node dysfunction in a patient with COVID-19.

A 46-year-old woman was admitted with coronavirus disease-2019 infection. Symptomatic sinus bradycardia occurred, followed by congestive heart failure. Therapeutics such as isoproterenol, theophylline, and cilostazol could not safely improve her symptoms. She underwent pacemaker implantation 53 days after admission. Atrial pacing remained was at 60% after 6 months.

Biomechanical Analysis of Serious Neck Injuries Resulting from Judo.

To establish a basis for initial diagnosis and for proposing preventive measures for the serious neck injuries occasionally experienced by judo practitioners, the biomechanical mechanisms of these injuries were analyzed. Two male judo experts repeatedly threw an anthropomorphic test device (POLAR dummy) using three throwing techniques (Seoi-nage, Osoto-gari, and Ouchi-gari). The dummy's kinematic data were captured using a high-speed digital camera, and the load and moment of the neck were measured with load cells. The neck injury criterion (Nij) and beam criterion were also calculated. In Seoi-nage, the anterior and parietal regions of the dummy's head contacted the tatami (judo mat). Subsequently, most of the body weight was applied, with the neck experiencing the highest compression. However, in Osoto-gari and Ouchi-gari, the occipital region of the dummy's head contacted the tatami. Significantly higher values of both Nij (median 0.68) and beam criterion (median 0.90) corresponding to a 34.7% to 37.1% risk of neck injury with an abbreviated injury scale score ≥2 were shown in Seoi-nage than in either Ouchi-gari or Osoto-gari. In judo, when thrown by the Seoi-nage technique, serious neck injuries can occur as a result of neck compression that occurs when the head contacts the ground.

[Successful management of a patient with myotonic dystrophy under total intravenous anesthesia with propofol, remifentnil and rocuronium bromide, combined with epidural anesthesia].

In general anesthesia for a patient with dystrophia myotonica (DM), respiratory depression and muscle weakness by opioid, as well as prolongation of the effect of muscle relaxant are seen postoperatively. Therefore it is desirable to choose agents with short duration of action and to dose these medicines to the minimum. We report a case of a 45-year-old woman with DM who underwent laparotomy for uterine cancer under general anesthesia combined with epidural anesthesia. Epidural catheter was placed from T 11-12, and anesthesia was inducted with propofol and remifentanil (RF). We administered rocuronium bromide (RB) 5 mg while watching TOF ratio with a muscle relaxation monitor (TOF-Watch). T1 became 0 after giving a dose of 10 mg, and intubation was performed. We maintained anesthesia by propofol and RF combined with epidural anesthesia. TOF ratio was restored to around 80% 90 minutes after RB administration, but we did not give supplemental doses because the operation went well smoothly. Recovery was smooth and fast. The respiratory depression and the muscle spasm were not noticed. RB and RE both with short duration of action, are useful in anesthesia management in DM cases.

Differences in severity of injuries between motorcyclist and bicyclist fatalities in single vehicle collisions.

To understand the injury severity of bicyclists and motorcyclists in single vehicle collisions, we performed a retrospective analysis of forensic autopsy cases of 25 motorcyclists and 14 bicyclists performed from 1999 to 2018. Collision details, injury characteristics, and involvement of alcohol were examined. The injury severity between bicyclists and motorcyclists was compared. The average age of victims was 62.3 years. All motorcyclists and no bicyclists wore a helmet. Motorcyclists had more severe injuries than bicyclists (mean Injury Severity Score of 42 and 27, respectively). The motorcyclists had more severe chest injuries but fewer severe facial injuries than bicyclists, owing to the difference in collision velocity or rate of helmet use (p < 0.05). Alcohol was present in the blood of 52.0% of bicyclists but no motorcyclists. The mean blood alcohol concentration of these bicyclists was 1.59 mg/mL. The bicyclists under the influence of alcohol had more severe injuries to neck and upper extremities than non-drunken bicyclists (p < 0.05). Our results may be useful for determining the cause of death and reconstructing the mechanisms of fatal injuries in bicyclists and motorcyclists.

Trans-aortic pulmonary vein isolation using magnetic navigation system for paroxysmal atrial fibrillation in a patient with dextrocardia, situs inversus, and inferior vena cava continuity with azygos vein.

A 51-year-old male with dextrocardia and situs inversus underwent catheter ablation for paroxysmal atrial fibrillation. Because the procedure through the trans-septal approach was impossible due to the inferior vena cava continuity with azygos vein, we performed pulmonary vein isolation using magnetic navigation system through the retrograde trans-aortic approach. Superior and inferior left-sided and superior right-sided pulmonary veins could be isolated which was confirmed by the ablation catheter. The patient was free from atrial fibrillation episode at the 12 months follow-up except only one palpitation episode lasting nearly 12 hours at 9 months after the ablation.

Impact of esophageal temperature monitoring guided atrial fibrillation ablation on preventing asymptomatic excessive transmural injury.

BACKGROUND: Even with the use of a reduced energy setting (20-25 W), excessive transmural injury (ETI) following catheter ablation of atrial fibrillation (AF) is reported to develop in 10% of patients. However, the incidence of ETI depends on the pulmonary vein isolation (PVI) method and its esophageal temperature monitor setting. Data comparing the incidence of ETI following AF ablation with and without esophageal temperature monitoring (ETM) are still lacking. METHODS: This study was comprised of 160 patients with AF (54% paroxysmal, mean: 24.0±2.9 kg/m(2)). Eighty patients underwent ablation accompanied by ETM. The primary endpoint was defined as the occurrence of ETI assessed by endoscopy within 5 d after the AF ablation. The secondary endpoint was defined as AF recurrence after a single procedure. If the esophageal temperature probe registered >39 °C, the radiofrequency (RF) application was stopped immediately. RF applications could be performed in a point-by-point manner for a maximum of 20 s and 20 W. ETI was defined as any injury that resulted from AF ablation, including esophageal injury or periesophageal nerve injury (peri-ENI). RESULTS: The incidence of esophageal injury was significantly lower in patients whose AF ablation included ETM compared with patients without ETM (0 [0%] vs. 6 [7.5%], p=0.028), but not the incidence of peri-ENI (2 [2.5%] vs. 3 [3.8%], p=1.0). AF recurrence 12 months after the procedure was similar between the groups (20 [25%] in the ETM group vs. 19 [24%] in the non-ETM group, p=1.00). CONCLUSIONS: Catheter ablation using ETM may reduce the incidence of esophageal injury without increasing the incidence of AF recurrence but not the incidence of peri-ENI.

Prophylactic catheter ablation of ventricular tachycardia before cardioverter-defibrillator implantation in patients with non-ischemic cardiomyopathy: Clinical outcomes after a single endocardial ablation.

BACKGROUND: Outcomes related to prophylactic catheter ablation (PCA) for ventricular tachycardia (VT) before implantable cardioverter-defibrillator (ICD) implantation in non-ischemic cardiomyopathy (NICM) are not well characterized. We assessed the efficacy of single endocardial PCA in NICM patients. METHODS: We retrospectively analyzed 101 consecutive NICM patients with sustained VT. We compared clinical outcomes of patients who underwent PCA (ABL group) with those who did not (No ABL group). Successful PCA was defined as no inducible clinical VT. We also compared the clinical outcomes of patients with successful PCA (PCA success group) with those of the No ABL group. Endpoints were appropriate ICD therapy (shock and anti-tachycardia pacing) and the occurrence of electrical storm (ES). RESULTS: PCA was performed in 42 patients, and it succeeded in 20. The time to ES occurrence was significantly longer in the ABL group than in the No ABL group (p=0.04). The time to first appropriate ICD therapy and ES occurrence were significantly longer in the PCA success group than in the No ABL group (p=0.02 and p<0.01, respectively). CONCLUSION: Single endocardial PCA can decrease ES occurrence in NICM patients. However, high rates of VT recurrence and low success rates are issues to be resolved; therefore, the efficacy of single endocardial PCA is currently limited.

The effectiveness of cardiac resynchronization therapy for patients with New York Heart Association class IV non-ambulatory heart failure.

BACKGROUND: We reviewed the effectiveness and safety of cardiac resynchronization therapy (CRT) for patients with New York Heart Association (NYHA) class IV non-ambulatory heart failure (NAHF). METHODS: From 2006 to 2011, 310 patients underwent CRT at Kobe University Hospital and Himeji Cardiovascular Center because of heart failure. Of these, 29 NAHF patients were retrospectively analyzed. The control group comprised 21 age- and ejection fraction-matched patients with NAHF who did not undergo CRT from the ICU database of Kobe University Hospital. The primary endpoint was all-cause death and hospitalization for heart failure. Response was defined as a >15% reduction in left ventricular end-systolic volume (LVESV). RESULTS: CRT was performed successfully without serious complications in all patients. Twenty-three patients (79%) were discharged 19±15 days after CRT implantation, while 6 (21%) died during their hospital stay due to progressive heart failure. Compared with the control group, patients in the CRT group showed significant improvements in the primary endpoint (log-rank p=0.04). Six patients (21%) were defined as responders and the Kaplan-Meier curve showed that responders experienced a better outcome than non-responders (log-rank p=0.029). LV dyssynchrony before implantation was significantly related to the occurrence of the primary endpoint (p=0.02). CONCLUSIONS: CRT can be safely used in patients with NAHF and can improve long-term patient outcomes, especially in treatment responders.