Feasibility of a novel atrial mechanical sensing method for leadless atrioventricular synchronous pacing.

INTRODUCTION: Few studies have demonstrated a high degree of atrioventricular (AV) synchrony with a new leadless pacemaker called Micra AV. Our group previously reported a new and unique sensing method. We believe that this novel sensing method, "Simplified A3 method," might facilitate better AV synchrony than a conventional sensing method in almost all cases with Micra AV implantation. METHODS: We conducted a non-randomized retrospective study comparing the two pacing methods at two centers. From December 1, 2021 to October 31, 2022, Micra AV was implanted for 32 patients at the two centers. Twenty of the 32 patients with sinus rhythm and complete AV block were included in this study. In Group 1, the conventional setting was programmed as follows: auto A3 threshold, auto A3 window-end (WE), and auto A4 threshold turned on during hospitalization. In Group 2, the "Simplified A3 method" was programmed as follows: auto A3 threshold and auto A3WE turned off. Instead, an intentionally prolonged A3WE (850-1000 ms) and low A3 threshold (A3 signal amplitude + 0.5-1.0 m/s2) were programmed. RESULTS: Twenty patients were analyzed. In Group 2, AV synchrony (%AMVp) was significantly higher at the first outpatient clinic (63.0 ± 5.7% vs 81.0 ± 4.2%, p = .03). A3 threshold was significantly lower in Group 2 (5.9 ± 0.7 m/s2, p < .05 vs 2.3 ± 0.5 m/s2, p < .05). CONCLUSION: Our novel sensing method might be a more feasible sensing method for obtaining higher AV synchrony than the conventional algorithm.

A case of cardiac sarcoidosis mimicking acute phase of takotsubo cardiomyopathy evaluated by multimodality cardiac imaging.

The patient was a 68-year-old woman who experienced loss of consciousness owing to a seizure while walking and bruised her face. Twelve­lead electrocardiography displayed a complete atrioventricular block. Transthoracic echocardiography displayed hypokinesis from the middle to apex of the myocardium. Emergency coronary angiography displayed no clear stenosis of the coronary arteries, and left ventriculography displayed takotsubo-like abnormal left ventricular wall motion. 99mTc-sestamibi/123I-beta-methyl iodophenyl pentadecanoic acid dual single-photon emission computed tomography displayed a perfusion/metabolism mismatch in the left apex, anterior segment, and inferior segment of the myocardium in the acute phase, which improved in the chronic phase. Similar mismatch findings were observed in the ventricular septum, which persisted in the chronic phase. Blood biomarkers of sarcoidosis were positive. Myocardial delayed enhancement was observed in the mid layer of the basal septum and inferior wall on cardiac magnetic resonance imaging. Fluorodeoxyglucose-positron emission tomography displayed signal accumulation in the basal septum. The clinical course of the patient suggested the possibility of cardiac sarcoidosis combined with takotsubo cardiomyopathy. This is a valuable case in which changes over time were detected by multimodality cardiac imaging. Learning objective: Cardiac manifestations of both takotsubo cardiomyopathy and sarcoidosis are similar, with both causing abnormal left ventricular wall motion. The co-occurrence of these conditions has been seldomly reported to date. The similarity of the characteristics of each condition poses a challenge in the diagnostic process. The utilization of multimodality cardiac imaging techniques, as demonstrated in the present case, is an effective means of establishing a diagnosis.

Pediatric hypertrophic cardiomyopathy caused by a novel TNNI3 variant.

TNNI3 is a gene that causes hypertrophic cardiomyopathy (HCM). A 14-year-old girl who was diagnosed with nonobstructive HCM presented with cardiopulmonary arrest due to ventricular fibrillation. Genetic testing revealed a novel de novo heterozygous missense variant in TNNI3, NM_000363.5:c.583A>T (p.Ile195Phe), which was determined to be the pathogenic variant. The patient exhibited progressive myocardial fibrosis, left ventricular remodeling, and life-threatening arrhythmias. Genetic testing within families is useful for risk stratification in pediatric HCM patients.

Second Micra leadless pacemaker implantation by using intracardiac echocardiography.

The strategy after battery depletion was not established in Micra leadless pacemaker system (Micra). There are still some concerns in the 2nd Micra implantation, such as the mechanical interaction between both devices. The position of the 2nd Micra should be placed apart from the 1st Micra. We present a case of 1st Micra battery depletion who successfully underwent the 2nd Micra implantation under the intracardiac echo guidance. In our case, intracardiac echo was a very effective tool for confirming the location of Micra implantation.

Nutritional Status and Sleep Quality Are Associated with Atrial Fibrillation in Patients with Obstructive Sleep Apnea: Results from Tokyo Sleep Heart Study.

The prevalence of obstructive sleep apnea (OSA) in patients with atrial fibrillation (AF) has been observed to be much higher than in control participants without AF. Limited data exist regarding the prevalence of AF in patients with OSA. The clinical characteristics, nutritional status, and sleep parameters associated with AF in patients with OSA remain unclear. In this study, we aimed to determine the prevalence and factors associated with AF in patients with OSA from a large Japanese sleep cohort (Tokyo Sleep Heart Study). This was a single-center explorative cross-sectional study. Between November 2004 and June 2018, we consecutively recruited 2569 patients with OSA who underwent an overnight full polysomnography at our hospital. They were assessed using a 12-lead ECG and echocardiography. The clinical characteristics, sleep parameters, and medical history were also determined. Of the OSA patients, 169 (6.6%) had AF. Compared with the non-AF patients, OSA patients with AF were older and male, and they had higher prevalence of a history of alcohol consumption, hypertension, chronic kidney disease, and undernutrition, as well as a reduced ejection fraction. With regard to the sleep study parameters, OSA patients with AF had reduced slow-wave sleep and sleep efficiency, as well as higher periodic limb movements. There were no significant differences in the apnea-hypopnea index or hypoxia index between the two groups. The logistic regression analysis demonstrated that age (OR = 4.020; 95% CI: 1.895-8.527; p < 0.001), a history of alcohol consumption (OR = 2.718; 95% CI: 1.461-5.057; p = 0.002), a high CONUT score (OR = 2.129; 95% CI: 1.077-4.209; p = 0.030), and reduced slow-wave sleep (OR = 5.361; 95% CI: 1.505-19.104; p = 0.010) were factors significantly related to AF. The prevalence of AF in patients with OSA was 6.6%. Age, a history of alcohol consumption, undernutrition, and reduced sleep quality were independent risk factors for the presence of AF in patients with OSA, regardless of the severity of OSA.

A case of short-coupled variant of Torsade de Pointes with bystander early repolarization in inferior leads.

The presence of J waves in cases of ventricular fibrillation (VF) is known to be a risk for sudden cardiac death. Recently, the effectiveness of radiofrequency catheter ablation (RFCA) for early repolarization syndrome (ERS) has been reported.The patient is a 30-year-old male with elevated J waves of 0.1 mV in the inferior leads, who had previously developed VF and undergone implantable cardioverter defibrillator (ICD) implantation. Because the VF from short coupled premature ventricular contraction (PVC) was presented, the RFCA of the triggered PVC was attempted. But it was unsuccessful due to no inducibility of the triggered PVC. After that, despite anti-arrythmia drug treatment, appropriate ICD shock for VF was observed. Although we decided to do a second ablation and evaluated epicardial arrhythmia substrate, no specific findings of early repolarization syndrome were found in the electrophysiological study. Finally, we considered that the cause of VF was short-coupled variant of Torsade de Pointes, and PVC ablation was performed. VF has not occurred since. We consider that this is a rare case to evaluate the epicardial arrhythmogenic substrate of J wave. Learning objective: Ablation of the epicardial arrhythmogenic substrate in patients with early repolarization syndrome (ERS) has been shown to be effective, but the relationship between abnormal epicardial potentials and the pathophysiology is unclear. In this case, J-wave and epicardial delayed potentials were not considered to represent obvious arrhythmogenic substrates. Ablation of the triggered premature ventricular contraction may be effective in ERS without apparent abnormal potentials.

Registry for Evaluating Healthy Life Expectancy and Long-Term Outcomes after Catheter Ablation of Atrial Fibrillation in the Very Elderly (REHEALTH AF) study: rationale and design of a prospective, multicentre, observational, comparative study.

INTRODUCTION: Data are lacking on the extent to which patients with non-valvular atrial fibrillation (AF) who are aged ≥80 years benefit from ablation treatment. The question pertains especially to patients' postablation quality of life (QoL) and long-term clinical outcomes. METHODS AND ANALYSIS: We are initiating a prospective, registry-based, multicentre observational study that will include patients aged ≥80 years with non-valvular AF who choose to undergo treatment by catheter ablation and, for comparison, such patients who do not choose to undergo ablation (either according to their physician's advice or their own preference). Study subjects are to be enrolled from 52 participant hospitals and three clinics located throughout Japan from 1 June 2022 to 31 December 2023, and each will be followed up for 1 year. The planned sample size is 660, comprising 220 ablation group patients and 440 non-ablation group patients. The primary endpoint will be the composite incidence of stroke/transient ischaemic attack (TIA) or systemic embolism (SE), another cardiovascular event, major bleeding and/or death from any cause. Other clinical events such as postablation AF recurrence, a fall or bone fracture will be recorded. We will collect standard clinical background information plus each patient's Clinical Frailty Scale score, AF-related symptoms, QoL (Five-Level Version of EQ-5D) scores, Mini-Mental State Examination (optional) score and laboratory test results, including measures of nutritional status, on entry into the study and 1 year later, and serial changes in symptoms and QoL will also be secondary endpoints. Propensity score matching will be performed to account for covariates that could affect study results. ETHICS AND DISSEMINATION: The study conforms to the Declaration of Helsinki and the Ethical Guidelines for Clinical Studies issued by the Ministry of Health, Labour and Welfare, Japan. Results of the study will be published in one or more peer-reviewed journals. TRIAL REGISTRATION NUMBER: UMIN000047023.

Effect of Catheter Ablation for Atrial Fibrillation in Heart Failure With Mid-Range or Preserved Ejection Fraction　- Pooled Analysis of the AF Frontier Ablation Registry and Hokuriku-Plus AF Registry.

BACKGROUND: A recent randomized trial demonstrated that catheter ablation for atrial fibrillation (AF) in patients with heart failure with reduced ejection fraction (EF) is associated with a reduction in death or heart failure. However, the effect of catheter ablation for AF in patients with heart failure with mid-range or preserved EF is unclear.Methods and Results: We screened 899 AF patients (72.4% male, mean age 68.4 years) with heart failure and left ventricular EF ≥40% from 2 Japanese multicenter AF registries: the Atrial Fibrillation registry to Follow the long-teRm Outcomes and use of aNTIcoagulants aftER Ablation (AF Frontier Ablation Registry) as the ablation group (525 patients who underwent ablation) and the Hokuriku-Plus AF Registry as the medical therapy group (374 patients who did not undergo ablation). Propensity score matching was performed in these 2 registries to yield 106 matched patient pairs. The primary endpoint was a composite of cardiovascular death and hospitalization for heart failure. At 24.6 months, the ablation group had a significantly lower incidence of the primary endpoint (hazard ratio 0.32; 95% confidence interval 0.13-0.70; P=0.004) than the medical therapy group. CONCLUSIONS: Compared with medical therapy, catheter ablation for AF in patients with heart failure and mid-range or preserved EF was associated with a significantly lower incidence of cardiovascular death or hospitalization for heart failure.

The Utility of a Lewis Lead for Distinguishing Atrioventricular Reentrant Tachycardia from Typical Atrioventricular Nodal Reentrant Tachycardia.

Objective The Lewis lead configuration is an alternative bipolar chest lead and it can help detect atrial activity. The utility of the Lewis lead to distinguish orthodromic atrioventricular reentrant tachycardia (AVRT) from typical atrioventricular nodal reentrant tachycardia (AVNRT) by visualizing the apparent retrogradely conducted P waves was investigated. Methods Forty-four patients with paroxysmal supraventricular tachycardia (PSVT) were included in this study. All patients had PSVT documented by an electrocardiogram (ECG) and underwent an electrophysiological study (EPS). During tachycardia, an ECG recording was performed using a Lewis lead with the electrode on the right aspect of the sternum at the second intercostal space instead of the right arm and the electrode on the fourth intercostal space instead of the left arm. The ECG parameters during tachycardia were compared between AVRT and AVNRT. Results Fourteen patients were diagnosed with AVRTs and 30 with typical AVNRTs on EPS. The positive P wave could be seen in the Lewis lead configuration in 9 of 14 patients with AVRTs and 21 of 30 patients with AVNRTs. P waves were more often visible in the Lewis lead configuration than in the standard leads (66% vs. 45%). The RP interval was significantly longer for AVRTs than for AVNRTs (88±17 vs. 154±34 ms, p<0.001), which yields 89% sensitivity and 71% specificity for distinguishing these 2 tachyarrhythmias with a cut-off point of 100 ms. Conclusion A Lewis lead configuration may help to make an accurate diagnosis among the reentrant supraventricular tachycardias prior to procedures, owing to its ability to locate P waves.

Impact of sinus rhythm maintenance on major adverse cardiac and cerebrovascular events after catheter ablation of atrial fibrillation: insights from AF frontier ablation registry.

The impact of catheter ablation for atrial fibrillation (AF) on cardiovascular events and mortality is controversial. We investigated the impact of sinus rhythm maintenance on major adverse cardiac and cerebrovascular events after AF ablation from a Japanese multicenter cohort of AF ablation. We investigated 3326 consecutive patients (25.8% female, mean age 63.3 ± 10.3 years) who underwent catheter ablation for AF from the atrial fibrillation registry to follow the long-term outcomes and use of anti coagulants after ablation (AF frontier ablation registry). The primary endpoint was a composite of stroke, transient ischemic attack, cardiovascular events, and all-cause death. During a mean follow-up of 24.0 months, 2339 (70.3%) patients were free from AF after catheter ablation, and the primary composite endpoint occurred in 144 (4.3%) patients. The AF nonrecurrence group had a significantly lower incidence of the primary endpoint (1.8 per 100 person-years) compared with the AF recurrence group (3.0 per 100 person-years, p = 0.003). The multivariate analysis revealed that freedom from AF (hazard ratio 0.61, 95% confidence interval 0.44-0.86, p = 0.005) was independently associated with the incidence of the composite event. In the multicenter cohort of AF ablation, sinus rhythm maintenance after catheter ablation was independently associated with lower rates of major adverse cardiac and cerebrovascular events.

Different Determinants of the Recurrence of Atrial Fibrillation and Adverse Clinical Events in the Mid-Term Period After Atrial Fibrillation Ablation.

BACKGROUND: It is unclear whether there are differences in the clinical factors between atrial fibrillation (AF) recurrence and adverse clinical events (AEs), including stroke/transient ischemic attack (TIA), major bleeding, and death, after AF ablation.Methods and Results:We examined the data from a retrospective multicenter Japanese registry conducted at 24 cardiovascular centers between 2011 and 2017. Of the 3,451 patients (74.1% men; 63.3±10.3 years) who underwent AF ablation, 1,046 (30.3%) had AF recurrence and 224 (6.5%) suffered AEs (51 strokes/TIAs, 71 major bleeding events, and 36 deaths) over a median follow-up of 20.7 months. After multivariate adjustment, female sex, persistent and long-lasting persistent AF (vs. paroxysmal AF), and stepwise increased left atrial diameter (LAd) quartiles were significantly associated with post-ablation recurrences. A multivariate analysis revealed that an age ≥75 years (vs. <65 years), body weight <50 kg, diabetes, vascular disease, left ventricular (LV) ejection fraction <40% (vs. ≥50%), Lad ≥44 mm (vs. <36 mm), and creatinine clearance <50 mL/min were independently associated with AE incidences, but not with recurrences. CONCLUSIONS: This study disclosed different determinants of post-ablation recurrence and AEs. Female sex, persistent AF, and enlarged LAd were determinants of post-ablation recurrence, whereas an old age, comorbidities, and LV and renal dysfunction rather than post-ablation recurrence were AEs determinants. These findings will help determine ablation indications and post-ablation management.

Clinical outcomes of ablation versus non-ablation therapy for atrial fibrillation in Japan: analysis of pooled data from the AF Frontier Ablation Registry and SAKURA AF Registry.

Whether ablation for atrial fibrillation (AF) is, in terms of clinical outcomes, beneficial for Japanese patients has not been clarified. Drawing data from 2 Japanese AF registries (AF Frontier Ablation Registry and SAKURA AF Registry), we compared the incidence of clinically relevant events (CREs), including stroke/transient ischemic attack (TIA), major bleeding, cardiovascular events, and death, between patients who underwent ablation (n = 3451) and those who did not (n = 2930). We also compared propensity-score matched patients (n = 1414 in each group). In propensity-scored patients who underwent ablation and those who did not, mean follow-up times were 27.2 and 35.8 months, respectively. Annualized rates for stroke/TIA (1.04 vs. 1.06%), major bleeding (1.44 vs. 1.20%), cardiovascular events (2.15 vs. 2.49%) were similar (P = 0.96, 0.39, and 0.35, respectively), but annualized death rates were lower in the ablation group than in the non-ablation group (0.75 vs.1.28%, P = 0.028). After multivariate adjustment, the risk of CREs was statistically equivalent between the ablation and non-ablation groups (hazard ratio [HR] 0.89, 95% confidence interval [CI] 0.71-1.11), but it was significantly low among patients who underwent ablation for paroxysmal AF (HR 0.68 [vs. persistent AF], 95% CI 0.49-0.94) and had a CHA2DS2-VASc score < 3 (HR 0.66 [vs. CHA2DS2-VASc score ≥ 3], 95% CI 0.43-0.98]). The 2-year risk reduction achieved by ablation may be small among Japanese patients, but AF ablation may benefit those with paroxysmal AF and a CHA2DS2-VASc score < 3.

Clinical Outcomes of Off-Label Underdosing of Direct Oral Anticoagulants After Ablation for Atrial Fibrillation.

Direct oral anticoagulants (DOACs) are sometimes prescribed at off-label under-doses for patients who have undergone ablation for atrial fibrillation (AF). This practice may be an attempt to balance the risk of bleeding against that of stroke or AF recurrence.We examined outcomes of 1163 patients who continued use of a DOAC after ablation. The patients were enrolled in a large (3530 patients) multicenter registry in Japan. The study patients were classified as 749 (64.4%) appropriate standard-dose DOAC users, 216 (18.6%) off-label under-dose DOAC users, and 198 (17.0%) appropriate low-dose DOAC users.Age and CHA2DS2-VASc scores differed significantly between DOAC dosing regimens, with patients given an appropriate standard-dose being significantly younger (63.3 ± 9.4 versus 64.8 ± 9.5 versus 73.2 ± 6.8 years, P < 0.0001) and lower (2.1 ± 1.5 versus 2.4 ± 1.6 versus 3.4 ± 1.4, P < 0.0001) than those given an off-label under-dose or an appropriate low-dose. During the median 19.0-month follow-up period, the AF recurrence rate was similar between the appropriate standard-dose and off-label under-dose groups but relatively low in the appropriate low-dose group (42.5% versus 41.2% versus 35.4%, P = 0.08). Annualized rates of thromboembolic events, major bleeding, and death from any cause were 0.47%, 0.70%, and 0.23% in the off-label under-dose group, while those rates were 0.74%, 0.73%, and 0.65% in the appropriate standard-dose, and 1.58%, 2.12%, and 1.57% in the appropriate low-dose groups.In conclusion, the clinical adverse event rates for patients on an off-label under-dose DOAC regimen after ablation, predicated on careful patient evaluations, was not high as seen with that of patients on a standard DOAC dosing regimen.

Efficacy of combined estrogen-progestin hormone contraception therapy for refractory coronary spastic angina in very young women.

Coronary spastic angina (CSA) in premenopausal women is rare, but has also been suggested to be associated with estrogen decline during the menstrual cycle. In this report, we describe the case of a young premenopausal patient with refractory CSA. She presented with ventricular fibrillation (VF) at the age of 15 years and was diagnosed as having CSA. She underwent implantation of an Implantable Cardioverter Defibrillator (ICD), and despite receiving systemic drug therapy at the maximum doses, she experienced a total of four appropriate ICD shocks over the subsequent six years. Based on careful history-taking, it was suspected that the angina episodes were closely related to the phase of the menstrual cycle. We started the patient on continuous combined estrogen-progestin hormone contraception therapy so as to prevent the reduction of the blood estrogen levels just prior to and during menstruation. After the start of this treatment, the patient became completely free of angina episodes. Although there are a few reports of the efficacy of hormone replacement therapy in premenopausal women with CSA, this is the first report of the efficacy of this therapy in a woman as young as 22 years old. .