Propensity-score matched comparison of renal and neurohormonal effects of catheter ablation for frequent premature ventricular contractions in patients with and without systolic dysfunction.

Background: Catheter ablation (CA) for premature ventricular contractions (PVCs) restores cardiac and renal functions in patients with reduced left ventricular ejection fraction (LVEF); however, its effects on preserved EF remain unelucidated. Methods: The study cohort comprised 246 patients with a PVC burden of >10% on Holter electrocardiography. Using propensity matching, we compared the changes in B-type natriuretic peptide (BNP) levels and estimated glomerular filtration rate (eGFR) in patients who underwent CA or did not. Results: Postoperative BNP levels were decreased significantly in the CA group, regardless of the degree of LVEF, whereas there was no change in those of the non-CA group. Among patients who underwent CA, BNP levels decreased from 44.1 to 33.0 pg/mL in those with LVEF ≥50% (p = .002) and from 141.0 to 87.9 pg/mL in those with LVEF <50% (p < .001). Regarding eGFR, postoperative eGFR was significantly improved in the CA group of patients with LVEF ≥50% (from 71.4 to 74.7 mL/min/1.73 m2, p = .006), whereas it decreased in the non-CA group. A similar trend was observed in the group with a reduced LVEF. Adjusted for propensity score matching, there was a significant decrease in the BNP level and recovery of eGFR after CA in patients with LVEF >50%. Conclusions: This study showed that CA for frequent PVCs decreases BNP levels and increases eGFR even in patients with preserved LVEF.

Higher power achieves greater local impedance drop, shorter ablation time, and more transmural lesion formation in comparison to lower power in local impedance guided radiofrequency ablation of atrial fibrillation.

BACKGROUND: Since the local impedance (LI) of the ablation catheter reflects tissue characteristics, the efficacy of higher power (HP) compared to lower power (LP) in LI-guided ablation may differ from other index-guided ablations. OBJECTIVE: This study aimed to assess the efficacy of HP ablation in LI-guided ablation of atrial fibrillation (AF). METHODS: A prospective observational study was conducted, enrolling patients undergoing de novo ablation for AF. Pulmonary vein isolation was performed using point-by-point ablation with a RHYTHMIA HDxTM Mapping System and an open-irrigated ablation catheter with mini-electrodes (IntellaNav MIFI OI). Ablation was stopped when the LI drop reached 30 ohms, three seconds after the LI plateaued, or when ablation time reached 30 s. To balance the baseline differences, a unique method was used in which the power was changed between HP (45 W to anterior wall/40 W to posterior wall) and LP (35 W/30 W) alternately for each adjacent point. RESULTS: A total of 551 ablations in 10 patients were analyzed (HP, n = 276; LP, n = 275). The maximum LI drop was significantly larger (HP: 28.3 ± 5.4 vs. LP: 24.8 ± 6.3 ohm), and the time to minimum LI was significantly shorter (HP: 15.0 ± 6.3 vs. LP: 19.3 ± 6.6 s) in the HP setting. The unipolar electrogram analysis of three patients revealed that the electrogram indicating transmural lesion formation was observed more frequently in the HP setting. CONCLUSION: In LI-guided ablation, the HP could achieve a larger LI drop and shorter time to minimum LI, which may result in more transmural lesion formation compared to a LP setting.

The angle of the tines before the pull and hold test predicts engagement of the tines in Micra leadless pacemaker implantation.

Background: Micra leadless pacemaker is secured to the myocardium by engagement of at least 2/4 tines confirmed with pull and hold test. However, the pull and hold test is sometimes difficult to assess. This study was performed to evaluate whether the angle of the tines before the pull and hold test predicts engagement of the tines in Micra leadless pacemaker implantation. Methods: We retrospectively enrolled 93 consecutive patients (52.7% male, age 82.4 ± 9.4 years), who received Micra implantation from September 2017 to June 2020 at our institution. After deployment and before the pull and hold test, the angle of the visible tines to the body of the pacemaker was measured using the RAO view of the fluoroscopy image. The engagement of the tines was then confirmed with the pull and hold test. Results: A total of 326 tines were analyzed. The angle of the engaged tines was significantly lower than the non-engaged tines (9.2 degrees [4.0-14.0] vs. 16.6 degrees [14.2-18.8], p < .0001). All tines with angles <10 degrees were engaged. In higher angles, engagement could not be predicted. Conclusion: A low angle of the tines before the pull and hold test can predict engagement of the tines in Micra leadless pacemaker implantation. The tines which are already open after deployment may be presumed that they are engaged.

Leadless pacemaker implantation sites confirmed by computed tomography and their parameters and complication rates.

BACKGROUND: Implantations of leadless pacemakers in the septum lower the risk of cardiac perforation. However, the relationship between the implantation site and the success rate, complication rate, and pacemaker parameters are not well-investigated. METHODS: Patients who underwent leadless pacemaker implantation with postprocedural computed tomography (CT) between September 2017 and November 2020 were analyzed. Septum was targeted with fluoroscopic guidance with contrast injection. We divided patients into two groups based on the implantation site confirmed by CT: septal and non-septal, which included the anterior/posterior edge of the septum and free wall. We compared the complication rates and pacemaker parameters between the two groups. RESULTS: A total of 67 patients underwent CT after the procedure; among them, 28 were included in the septal group and 39 were included in the non-septal group. The non-septal group had significantly higher R wave amplitudes (6.5 ± 3.3 vs. 9.7 ± 3.9 mV, p = .001), lower pacing threshold (1.0 ± 0.94 vs. 0.63 ± 0.45 V/0.24 ms, p = .02), and higher pacing impedance (615 ± 114.1 vs. 712.8 ± 181.3 ohms, p = .014) after the procedure compared to the septal group. Cardiac injuries were observed in four patients (one cardiac tamponade, one possible apical hematoma, two asymptomatic pericardial effusion), which were only observed in the non-septal group. CONCLUSIONS: Leadless pacemaker implantation may be technically challenging with substantial number of patients with non-septal implantation when assessed by CT. Septal implantation may have a lower risk of cardiac injury but may lead to inferior pacemaker parameters than non-septal implantation.

Should fast pathway ablation be reconsidered in typical atrioventricular nodal re-entrant tachycardia?

INTRODUCTION: Atrioventricular nodal re-entry tachycardia (AVNRT) is the most common, regular narrow-complex tachycardia. The established treatment is catheter ablation of the AV nodal slow pathway (SP). However, in a select group of patients with long PR intervals in sinus rhythm, SP ablation can lead to AV block due to the absence of robust anterograde conduction through the fast pathway (FP). This report aims to demonstrate that AV nodal FP ablation is a reasonable approach in patients with AVNRT and poor or absent anterograde FP conduction. METHODS AND RESULTS: Standard electrophysiology study techniques were used in the electrophysiology laboratory. Catheter ablations were performed using radiofrequency energy. Mapping of intracardiac activation was performed with electroanatomical mapping systems. Outcomes were assessed acutely during the procedure and during routine clinical follow-up. Six patients with first-degree AV block and recurrent AVNRT who underwent ablation of their tachycardia at our institution are presented. One patient underwent ablation of AV nodal SP resulting in high-degree AV block necessitating pacemaker implantation. The remaining five patients underwent ablation of the AV nodal FP guided by electroanatomical mapping of the earliest atrial activation in tachycardia. These five had successful treatment of the tachycardia with preservation of anterograde AV nodal conduction. Mapping and ablation approach to eliminate retrograde FP conduction are described. CONCLUSION: In select patients with AVNRT and poor anterograde FP conduction, retrograde FP ablation is reasonable and is less likely to result in AV block and pacemaker dependency.

Remote Monitoring for Chronic Disease Management: Atrial Fibrillation and Heart Failure.

This review aims to cover the latest evidence of remote monitoring of cardiac implantable electronic devices for the management of atrial fibrillation and heart failure. Remote monitoring is useful for early detection for device-detected atrial fibrillation, which increases the risk of thromboembolic events. Early anticoagulation based on remote monitoring potentially reduces the risk of stroke, but optimal alert setting needs to be clarified. Multiparameter monitoring with automatic transmission is useful for heart failure management. Improved adherence to remote monitoring and an optimal algorithm for transmitted alerts and their management are warranted in the management of heart failure.

The effects of intravenous anesthetics on QT interval during anesthetic induction with desflurane.

INTRODUCTION: This study aimed to determine the effects of the interaction between intravenous anesthetics and desflurane on the QT interval. METHODS: Fifty patients who underwent lumbar spine surgery were included. The patients received 3 µg/kg fentanyl and were randomly divided into two groups: group P patients received 1.5 mg/kg propofol and group T patients received 5 mg/kg thiamylal 2 min after fentanyl injection. All patients received rocuronium and desflurane (6% inhaled concentration) after loss of consciousness. Tracheal intubation was performed 3 min after rocuronium injection. Heart rate (HR), mean arterial pressure (MAP), bispectral index score (BIS), and the heart rate-corrected QT (QTc) interval on a 12-lead electrocardiograms were recorded before fentanyl injection (T1), 2 min after fentanyl injection (T2), 1 min after propofol or thiamylal injection (T3), immediately before intubation (T4), and 2 min after intubation (T5). RESULTS: There were no significant intergroup differences in patient characteristics. BIS and MAP decreased after anesthesia induction in both groups. MAP values at T3, T4, and T5 in group T were higher than those in group P. HR did not change over time or differ between the groups. The QTc intervals at T4 and T5 in group T were longer than those at T1. In group P, the QTc interval at T3 was significantly shorter than that at T1. The QTc intervals at T3, T4, and T5 in group T were significantly longer than those in group P. CONCLUSIONS: A propofol injection could counteract the QTc interval prolongation during desflurane anesthesia induction. TRIAL REGISTRATION: UMIN Clinical Trials Registry database reference number: UMIN000023707 . This study was registered on August 21, 2016.

Feasibility, safety, and potential demand of emergent brain magnetic resonance imaging of patients with cardiac implantable electronic devices.

BACKGROUND: The feasibility, safety, and potential demand of emergent magnetic resonance imaging (MRI) of patients with a cardiac implantable electronic device (CIED) in emergency situations are unknown. METHODS: We retrospectively compared emergent and scheduled MRI orders for patients with CIEDs at Kameda General Hospital, a tertiary hospital in Japan, from October 2012 to September 2016. RESULTS: We identified 11 emergent MRI orders via the emergency room and 38 scheduled MRI orders. Although the baseline characteristics were similar between the two groups, brain scanning was predominant in emergent scanning (p=0.002). The reasons for MRI and physicians who ordered it were also significantly different between the two groups (p<0.001, p=0.03, respectively). Among the emergent orders via the emergency room, 10 out of 11 were brain scans. Nine out of 10 patients underwent successful emergent brain MRI. The time from arrival at the emergency room to MRI was 144±29 min, and the time from the MRI order made by the cardiologist to its actual performance was 60±10 min. Four out of 9 patients had a diagnosis of acute stroke confirmed by emergent MRI, and two had emergent thrombolysis with a complete neurological recovery. All emergent scanning was conducted safely with no complications. CONCLUSIONS: Our study found the potential demand of brain MRI of patients with CIEDs in emergency situations compared with scheduled scanning, which was shown to be feasible and safe for the diagnosis and treatment of an acute stroke.

Remote monitoring to Improve long-term prognosis in heart failure patients with implantable cardioverter-defibrillators.

INTRODUCTION: Strong evidence exists for the utility of remote monitoring in cardiac implantable electronic devices for early detection of arrhythmias and evaluation of system performance. The application of remote monitoring for the management of chronic disease such as heart failure has been an active area of research. Areas covered: This review aims to cover the latest evidence of remote monitoring of implantable cardiac defibrillators in terms of heart failure prognosis. This article also updates the current technology relating to the method and discusses key factors to be addressed in order to better use the approach. PubMed and internet searches were conducted to acquire most recent data and technology information. Expert commentary: Multiparameter monitoring with automatic transmission is useful for heart failure management. Improved adherence to remote monitoring and an optimal algorithm for transmitted alerts and their management are warranted in the management of heart failure.

Histological examination of the right atrial appendage after failed catheter ablation for focal atrial tachycardia complicated by cardiogenic shock in a post-partum patient.

A 26-year-old woman in her first pregnancy presented with persistent atrial tachycardia (AT). AT was resistant to medications, cardioversions, and the first attempt of catheter ablation. Two months after delivery she developed severe systolic dysfunction and circulatory collapse. Emergent catheter ablation was performed with the support of percutaneous cardiopulmonary bypass and intraaortic balloon pump. The AT originated in the apex of the right atrial appendage (RAA). Repeated attempts at ablation were unsuccessful, prompting surgical RAA resection, which terminated the tachycardia and improved the cardiac function. Histological examination of resected RAA provided insights into mechanism of resistance to catheter ablation.

Moderate vasomotor response to acetylcholine provocation test as an indicator of long-term prognosis.

The acetylcholine (ACh) provocation test (ACh-test) is used for the diagnosis of vasospastic angina (VSA). However, subjects often show a moderate spasm (MS) response for which diagnosis of VSA is not definitive, and the clinical significance of this response is unknown. We assessed moderate coronary vasomotor response to the ACh test as an indicator of long-term prognosis. A total of 298 consecutive patients who underwent the ACh test for suspected VSA were retrospectively investigated. Coronary spasm severity after intracoronary administration of isosorbide dinitrate was evaluated by measuring epicardial coronary artery diameter reduction after ACh injection. Patients were divided into three groups according to the diameter reduction during the ACh test: severe spasm (SS) showing ≥75 % diameter reduction, MS showing ≥50 % diameter reduction, and others (N). In Kaplan-Meier analysis, the major adverse cardiac event (MACE) rates with a median follow-up of 4.6 years were significantly worse in SS (11.1 %) and MS (8.5 %) than N (1.9 %), (SS vs N; P = 0.009, MS vs N; P = 0.029). Significant difference in MACE rates was not observed between SS and MS (P = 0.534). Cox regression analysis revealed that MS remained an independent predictor of MACE after adjustment for other confounders (HR: 7.18, 95 % CI 1.42-36.4, P = 0.017). Patients with MS by ACh test had a cardiac event rate comparable with that of patients with SS and significantly worse than that of patients with normal vasomotor responses.

Prognostic implications of chronic kidney disease and anemia after percutaneous coronary intervention in acute myocardial infarction patients.

Anemia is a common complication of chronic kidney disease (CKD), and a few studies suggest that both CKD and anemia have a marked impact on the prognosis of patients with cardiovascular disease. We retrospectively analyzed the prevalence of CKD and anemia in 312 patients with acute myocardial infarction (AMI). The patients were divided into four groups according to the presence of CKD and anemia. Chronic kidney disease was defined as estimated glomerular filtration rate <60 ml/min/1.73 m(2), and anemia was defined according to the World Health Organization definition. Of 312 AMI patients, 166 (53.2%) had CKD and 87 (27.8%) had anemia. A powerful relationship was observed between both CKD and anemia and major adverse cardiac and cerebrovascular events (MACCE) or death by any cause. After adjustment for comorbidities, the hazard ratio (HR) for MACCE was significantly higher in the anemia-only group (HR 5.42, 95% confidence interval (CI) 1.38-21.27, P = 0.015), the CKD-only group (HR 6.4, 95% CI 2.09-19.58, P = 0.001), and the CKD and anemia group (HR 11.61, 95% CI 3.65-36.89, P < 0.001). With respect to death by any cause, the HR was significantly higher in the CKD-only group (HR 2.68, 95% CI 1.02-7.02, P = 0.045) and the CKD and anemia group (HR 4.40, 95% CI 1.56-12.43, P = 0.005). One-half of the patients with AMI had CKD as well. Furthermore, when anemia coexisted with CKD, these conditions had a multiplicative amplification effect on the risk of MACCE and death by any cause in patients with AMI.

Prevalence and prognostic implications of pre-diabetic state in patients with heart failure.

BACKGROUND: Diabetes mellitus (DM) is a risk factor of poor prognosis in patients with heart failure (HF). The prevalence and prognostic impact of the pre-diabetic state, however, are not well understood. METHODS AND RESULTS: One hundred and thirty-six consecutive patients admitted due to HF were included in this prospective study. The 75-g oral glucose tolerance test (OGTT) was performed in all patients without known DM, and patients were classified into normal glucose tolerance (NGT), impaired fasting glucose (IFG), impaired glucose tolerance (IGT), and DM groups. Forty-two of the 136 patients had previously been diagnosed with diabetes. Of the remaining 94 patients without known diabetes, 35 (37.2%) patients were classified as NGT, 9 (9.6%) as having IFG, 37 (39.4%) were classified as having IGT, and 13 (13.8%) were newly diagnosed with DM. During follow-up, patients with DM or IGT had significantly lower major adverse cardiac and cerebrovascular event (MACCE)-free rates than NGT patients (P=0.006, P=0.036, respectively). IFG, however, was not significantly related to increased MACCE risk. The presence of IGT (hazard ratio [HR], 4.51; P=0.011) and DM (HR, 4.74; P=0.005) were independent predictors of MACCE even after multivariate analysis. CONCLUSIONS: IGT and DM contribute to adverse prognosis in patients with HF. It is feasible to perform diabetes screening using OGTT in patients with HF for risk stratification.

Endothelial dysfunction in paroxysmal atrial fibrillation as a prothrombotic state. Comparison with permanent/persistent atrial fibrillation.

AIM: Atrial fibrillation (AF), regardless of subtype, is associated with a prothrombotic state, which is related to endothelial dysfunction (ED).We hypothesized that paroxysmal atrial fibrillation (PAF) patients have endothelial dysfunction, and this may partially explain the high thromboembolic risk and poorer outcome in this category of patients. METHODS: The study population consisted of 100 consecutive outpatients with AF (mean age 65.9±7.9 years; 68 (68%) male) and 21 characteristics and comorbidity matched control subjects (mean age 64.8±7.0 years; 13 (61.9%) male). AF patients were divided into the PAF group (n=50) and permanent/persistent AF (PeAF) group (n=50).Reactive hyperemia pulse amplitude tonometry index (RHI) was measured to evaluate endothelial function. RESULTS: RHI was significantly lower in the PAF (1.67±0.30) and PeAF (1.63±0.28) groups in comparison with control subjects (2.12±0.40, both p< 0.001). There was no significant difference in RHI between the PAF and PeAF groups (p= 0.88). On linear regression analysis, both PeAF and PAF are significant independent predictors of RHI. CONCLUSIONS: In conclusion, ED in PAF patients was comparable to PeAF patients, and the presence of PAF itself is a contributing factor for ED independent of other coexisting comorbidities. This may provide a mechanism explaining why the risk of thromboembolism in PAF is comparable with PeAF patients.