Ablation index-guided high-power vs. moderate-power cavotricuspid isthmus ablation.

Ablation index (AI)-guided ablation is useful for pulmonary vein isolation (PVI) and cavotricuspid isthmus (CTI) ablation. However, the impact of radiofrequency (RF) application power on CTI ablation with a fixed target AI remains unclear. One-hundred-thirty drug-refractory atrial fibrillation and/or atrial flutter patients who underwent AI-guided CTI ablation with or without PVI between July 2020 and August 2021 were randomly assigned to high-power (45 W) and moderate-power (35 W) groups. We performed CTI ablation with the same target AI value in both groups: 500 for the anterior 1/3 segments and 450 for the posterior 2/3 segments. In total, first-pass conduction block of the CTI was obtained in 111 patients (85.4%), with 7 patients (5.4%) showing CTI reconnection. The rate of first-pass conduction block was significantly higher in the 45 W group (61/65, 93.8%) than in the 35 W group (50/65, 76.9%, P = 0.01). CTI ablation and CTI fluoroscopy time were significantly shorter in the 45 W group than in the 35 W group (CTI ablation time: 192.3 ± 84.8 vs. 319.8 ± 171.4 s, P < 0.0001; CTI fluoroscopy time: 125.2 ± 122.4 vs. 171.2 ± 124.0 s, P = 0.039). Although there was no significant difference, steam pops were identified in two patients from the 45 W group at the anterior segment of the CTI. The 45 W ablation strategy was faster and provided a higher probability of first-pass conduction block than the 35 W ablation strategy for CTI ablation with a fixed AI target.

Prediction of atrioventricular conduction disturbance after ablation of persistent atrial fibrillation.

The prevalence of atrioventricular conduction disturbance (AVCD) in patients with persistent atrial fibrillation (AF) has not yet been fully investigated. We sought to identify the predictors of AVCD in patients with AF by analyzing the relationship between pre-ablation heart rate during AF and the PR interval in sinus rhythm after ablation. We analyzed pre-ablation 24-h Holter electrocardiogram (ECG) and 12 lead ECG 12 months after ablation of 121 consecutive patients with persistent AF who underwent their first ablation procedure and maintained sinus rhythm at 12 months. AVCD was defined as a first-degree atrioventricular block (AVB), second-degree AVB, high-degree AVB, or third-degree AVB observed on ECG at 12 months after ablation. Seventeen out of 121 patients (14.0%) had AVCD at 12 months. In the group with AVCD, total heartbeat (THB) and maximum heart rate (Max HR) were significantly lower, and the prevalence of concomitant Cavo-tricuspid isthmus-dependent atrial flutter before ablation and the appearance of macro reentrant atrial tachycardia (AT) during the procedure were significantly higher than those in the group without AVCD. Multiple regression analysis revealed that maximum HR and macro reentrant AT were significant predictors of AVCD. Receiver operating characteristic curve analysis revealed that Max HR of <165.0 bpm predicts AVCD with a sensitivity of 76.47% and a specificity of 74.00%. In patients with persistent AF, low Max HR and the presence of macro reentrant AT during the ablation procedure were predictors of AVCD.

One-year outcome after percutaneous coronary intervention in nonagenarians: Insights from the J-PCI OUTCOME registry.

BACKGROUND: Nonagenarian patients who undergo percutaneous coronary intervention (PCI) are increasing, and a few previous studies have reported their long-term outcomes. However, differences in their long-term outcomes between generations remain unclear. This study aimed to investigate 1-year all-cause and cardiovascular (CV) mortality, and major adverse cardiovascular events (MACE; cardiovascular death, myocardial infarction, and stroke) of nonagenarian patients who underwent PCI compared with the other elder patients, using a nationwide registration system. METHODS: The patient-level data registered between January 2017 and December 2017 was extracted from the J-PCI OUTCOME Registry endorsed by the Japanese Association of Cardiovascular Intervention and Therapeutics (CVIT). The one-year all-cause and cardiovascular (CV) mortality, MACE, and major bleeding events were identified. RESULTS: Out of 40,722 patients over 60 years of age, 880 (2.1%) were nonagenarians. For nonagenarians, the 1-year mortality rate was substantial (13.5%). The MACE and CV death rates were also high (8.1%, and 6.8%, respectively) for nonagenarians, and these event rates were approximately 1.5 times higher in nonagenarians than octogenarians. Multivariate regression analysis showed that presentation with cardiogenic shock [hazard ratio (HR) 2.32; 95 confidence intervals (CI): 1.22-4.41], or cardiac arrest (HR 2.91; 90% CI: 1.28-6.62), and use of oral anticoagulants (HR 2.10; 90% CI: 1.07-4.12) were the predictors of 1-year MACE. CONCLUSIONS: Even in the contemporary era, nonagenarians who have undergone PCI still face a considerably increased risk for adverse cardiovascular events that reduces long-term survival. In addition to having poorer lesion characteristics, adverse events, including death, MACEs, and major bleeding, occurred 1.5 times more frequently in nonagenarians than in octogenarians.

Prolongation of QT interval after pulmonary vein isolation for paroxysmal atrial fibrillation.

INTRODUCTION: Pulmonary vein isolation (PVI) affects the ganglionated plexi (GP) around the atrium leading to a modification of intrinsic cardiac autonomic system (ANS). In animal models, GP ablation has the potential risk of QT prolongation and ventricular arrhythmias. However, the impact of PVI on QT intervals in human remains unclear. METHODS AND RESULTS: We analyzed electrocardiograms of 117 consecutive patients with paroxysmal atrial fibrillation (AF) who underwent their first PVI procedures and maintained sinus rhythm without antiarrhythmic drugs at all evaluation points (4 h, 1 day, 1 month, and 3 months after PVI). Heart rate significantly increased at 4 h, 1 day, and 1 month. Raw QT interval prolonged at 4 h (417.1 ± 41.6 ms, p < .001) but shortened at 1 day (376.4 ± 34.1 ms, p < .001), 1 month (382.2 ± 31.5 ms, p < 0.001), and 3 months (385.1 ± 32.8 ms, p < 0.001) compared with baseline (391.6 ± 31.4 ms). Bazett-corrected QTc intervals were significantly prolonged at 4 h (430.8 ± 27.9 ms, p < .001), 1 day (434.8 ± 22.3 ms, p < .001), 1 month (434.8 ± 22.3 ms, p < .001), and 3 months (420.1 ± 21.8 ms, p < .001) compared with baseline (404.9 ± 25.2 ms). Framingham-corrected QTc intervals significantly prolonged at 4 h (424.1 ± 26.6 ms, p < .001) and 1 day (412.3 ± 29.3 ms, p < .01) compared with baseline (399.2 ± 22.7 ms). Multiple regression analysis revealed that female sex is a significant predictor of raw QT and QTc interval increase at 4 h after PVI. CONCLUSION: Raw QT and QTc were prolonged after PVI, especially in the acute phase. Female sex is a risk factor for QT increase.

Coronary sinus catheter placement via left cubital vein for phrenic nerve stimulation during pulmonary vein isolation.

Phrenic nerve (PN) stimulation is essential for the elimination of PN palsy during balloon-based pulmonary vein isolation (PVI). Although ultrasound-guided vascular access is safe, insertion of a PN stimulation catheter via central venous access carries a potential risk of the development of mechanical complications. We evaluated the safety of a left cubital vein approach for positioning a 20-electrode atrial cardioversion (BeeAT) catheter in the coronary sinus (CS), and the feasibility of right PN pacing from the superior vena cava (SVC) using proximal electrodes of the BeeAT catheter. In total, 106 consecutive patients who underwent balloon-based PVI with a left cubital vein approach for BeeAT catheter positioning were retrospectively assessed. The left cubital approach was successful in 105 patients (99.1%), and catheter insertion into the CS was possible for 104 patients (99.0%). Among these patients, constant right PN pacing from the SVC was obtained for 89 patients (89/104, 85.6%). In five patients, transient loss of right PN capture occurred during right pulmonary vein ablation. No persistent right PN palsy was observed. Small subcutaneous hemorrhage was observed in eight patients (7.5%). Neuropathy, pseudoaneurysm, arteriovenous fistula, and perforations associated with the left cubital approach were not detected. Body mass index was significantly higher in the right PN pacing failure group than in the right PN pacing success group (26.2 ± 3.2 vs. 23.8 ± 3.8; P = 0.025). CS catheter placement with a left cubital vein approach for right PN stimulation was found to be safe and feasible. Right PN pacing from the SVC using a BeeAT catheter was successfully achieved in the majority of the patients. This approach may prove to be preferable for non-obese patients.

Evaluation of the risk factors for ventricular arrhythmias secondary to QT prolongation induced by papaverine injection during coronary flow reserve studies using a 4 Fr angio-catheter.

Estimation of the fractional flow reserve (FFR) is considered to be an established method by which to assess stable coronary artery stenosis. Induction of maximal coronary hyperemia is important during the FFR procedure. Papaverine has been reported to increase the risk of ventricular arrhythmia (VA). The purpose of the present study was to discover predictors of papaverine-induced VAs developing during FFR measurement. A total of 213 clinically stable patients were included in the study. FFRs were determined after intracoronary papaverine administration (12 mg into the left and 8 mg into the right coronary arteries). We compared patients in whom VA did and did not develop in terms of clinical and electrocardiogram characteristics. FFR measurements were performed on 244 lesions (133 in the left anterior descending arteries, 43 in the left circumflex arteries, and 68 in the right coronary arteries). We found that the QTc interval was prolonged in all patients after papaverine administration (average post-administration QTc interval = 569 ± 89 ms; average ΔQTc interval = 144 ± 80 ms). VA developed in three patients with significantly prolonged QT intervals (average post-administration QTc interval = 639 ± 19 ms, average ΔQTc interval = 220 ± 64 ms, p < 0.02) and transitioned from torsade de pointes to ventricular fibrillation. Bradycardia (< 50 beats/min), hypokalemia (serum K < 3.5 mEp/L), and low left ventricular function (ejection fraction (EF) < 50%) were associated with VA (bradycardia, p < 0.01; hypokalemia, p < 0.01; low left ventricular function, p < 0.01). Three-vessel disease was significantly predictive of VA (p < 0.003). In the three-vessel group, the complications of low left ventricular function, hypokalemia, and bradycardia were significantly associated with VA (p < 0.045). Three-vessel disease is a predictor of the development of VA during FFR measurement performed with the aid of papaverine, especially if accompanied by one or more of the following: low left ventricular function, hypokalemia, or bradycardia.

Preclose Versus Postclose Using Suture-Mediated Vascular Closure System for Catheter Ablation With Femoral Vein Access.

BACKGROUND: Differences in the efficacy and safety between the preclose and postclose suture-mediated vascular closure systems for femoral vein access have not been adequately studied. OBJECTIVES: This study aimed to evaluate the efficacy and safety of these 2 suturing techniques in femoral vein access. METHODS: Patients subjected to elective catheter ablation via the femoral vein using a sheath of 8- to 13-F inner diameter (n = 282) were randomized to the preclose or postclose groups for the single-suture technique using ProGlide/ProStyle (Abbott Vascular). Duplex ultrasound was performed on days 1 and 90 after the procedure to evaluate vascular complications. The primary efficacy endpoint was rebleeding requiring recompression, and the primary safety endpoint was any major complication occurring within 90 days. The secondary efficacy endpoints included time to hemostasis and time to ambulation, and the secondary safety endpoint was any minor complication occurring within 90 days. RESULTS: The preclose group demonstrated a significantly lower rebleeding rate (5 of 141 [3.5%] vs 15 of 141 [10.6%]; P = 0.03) and shorter time to hemostasis (254.0 ± 120.4 seconds vs 299.8 ± 208.2 seconds; P = 0.02) compared with the postclose group. Five patients in each group were lost to follow-up at 90 days. Incidence of major complications were similar in both groups (1 of 136 [0.7%]; P = 1.00), whereas minor complications were observed in 18 of 136 (13.2%) and 21 of 136 (15.4%) patients in the preclose and postclose groups, respectively, without a significant difference (P = 0.73). CONCLUSIONS: In femoral vein access using the single-suture technique with ProGlide/ProStyle, the preclose technique presented a higher hemostasis rate than the postclose technique, without compromising safety.

Detection of Epicardial Connection Through Intercaval Bundle Involving Right Pulmonary Veins After Ipsilateral Circumferential Ablation by Intra-Atrial Activation Sequence Pacing From the Right Pulmonary Vein.

BACKGROUND: An epicardial connection (EC) through the intercaval bundle (EC-ICB) between the right pulmonary vein (RPV) and right atrium (RA) is one of the reasons for the need for carina ablation for PV isolation and may reduce the acute and chronic success of PV isolation. We evaluated the intra-atrial activation sequence during RPV pacing after failure of ipsilateral RPV isolation and sought to identify specific conduction patterns in the presence of EC-ICB. METHODS AND RESULTS: This study included 223 consecutive patients who underwent initial catheter ablation of atrial fibrillation. If the RPV was not isolated using circumferential ablation or reconnected during the waiting period, an exit map was created during mid-RPV carina pacing. If the earliest site on the exit map was the RA, the patient was classified into the EC-ICB group. The exit map, intra-atrial activation sequence, and RPV-high RA time were evaluated. First-pass isolation of the RPV was not achieved in 36 patients (16.1%), and 22 patients (9.9%) showed reconnection. Twelve and 28 patients were classified into the EC-ICB and non-EC-ICB groups, respectively, after excluding those with multiple ablation lesion sets or incomplete mapping. The intra-atrial activation sequence showed different patterns between the 2 groups. The RPV-high RA time was significantly shorter in the EC-ICB than in the non-EC-ICB group (69.2±15.2 versus 148.6±51.2 ms; P<0.001), and RPV-high RA time<89.0 ms was highly predictive of the existence of an EC-ICB (sensitivity, 91.7%; specificity, 89.3%). CONCLUSIONS: An EC-ICB can be effectively detected by intra-atrial sequencing during RPV pacing, and an RPV-high RA time of <89.0 ms was highly predictive.

Successful revascularization with percutaneous coronary intervention using a combination of the subintimal transcatheter withdrawal technique and coronary artery fenestration for spontaneous coronary artery dissection.

The combination of the STRAW technique and coronary artery fenestration using a cutting balloon could be effective in SCAD patients, especially with dissection to the distal end of the coronary artery.

Torsade de Pointes Due to QT Prolongation after Pulmonary Vein Isolation for Persistent Atrial Fibrillation.

We herein report a 60-year-old woman with long-standing persistent atrial fibrillation (AF) who developed QT prolongation and torsade de pointes (TdP) after pulmonary vein isolation (PVI). When electrical cardioversion was performed three months before PVI, prominent QT prolongation was not observed. QT prolongation emerged after PVI and was sustained until AF recurrence on the third day after ablation, and TdP disappeared along with AF recurrence. PVI affects the ganglionated plexi around the atrium, leading to modification of the intrinsic cardiac autonomic system. This case indicates that PVI has the potential risk of inducing lethal ventricular arrhythmias due to QT prolongation.

Altered firing pattern of single-unit muscle sympathetic nerve activity during handgrip exercise in chronic heart failure.

Sympathetic activation in chronic heart failure (CHF) is greatly augmented at rest but the response to exercise remains controversial. We previously demonstrated that single-unit muscle sympathetic nerve activity (MSNA) provides a more detailed description of the sympathetic response to physiological stress than multi-unit nerve recordings. The purpose of this study was to determine whether the reflex response and discharge properties of single-unit MSNA are altered during handgrip exercise (HG, 30% of maximum voluntary contraction for 3 min) in CHF patients (New York Heart Association functional class II or III, n = 16) compared with age-matched healthy control subjects (n = 13). At rest, both single-unit and multi-unit indices of sympathetic outflow were augmented in CHF compared with controls (P < 0.05). However, the percentage of cardiac intervals that contained one, two, three or four single-unit spikes were not different between the groups. Compared to the control group, HG elicited a larger increase in multi-unit total MSNA (Delta1002 +/- 50 compared with Delta636 +/- 76 units min(-1), P < 0.05) and single-unit MSNA spike incidence (Delta27 +/- 5 compared with Delta8 +/- 2 spikes (100 heart beats)(-1)), P < 0.01) in the CHF patients. More importantly, the percentage of cardiac intervals that contained two or three single-unit spikes was increased (P < 0.05) during exercise in the CHF group only (Delta8 +/- 2% and Delta5 +/- 1% for two and three spikes, respectively). These results suggest that the larger multi-unit total MSNA response observed during HG in CHF is brought about in part by an increase in the probability of multiple firing of single-unit sympathetic neurones.

Impact of intravascular ultrasound-guided minimum-contrast coronary intervention on 1-year clinical outcomes in patients with stage 4 or 5 advanced chronic kidney disease.

This study aims to elucidate 1-year clinical outcomes using this technique for patients with stage 4 or 5 advanced chronic kidney disease (CKD). Research has proven that imaging-guided percutaneous coronary intervention (PCI) reduces contrast volume significantly; however, only short-term clinical benefits have been reported. Minimum-contrast (MINICON) studies are based on the registry design pattern to enroll PCI results in patients with advanced CKD stage 4 or 5 comorbid with coronary artery disease. We excluded cases of emergency PCI or maintenance dialysis from this study. In this study, we compared the intravascular ultrasound (IVUS)-guided MINICON PCI group (n = 98) with the angiography-guided standard PCI group (n = 86). Enrollment of the MINICON studies started in 2006. Before 2012, IVUS-guided MINICON PCI was performed only in 14% (stage 1), but it was 100% after 2012 (stage 2). The enrollment finished in 2016. The IVUS-guided MINICON PCI group exhibited a significantly reduced contrast volume (22 ± 20 vs. 130 ± 105 mL; P < 0.0001) and contrast-induced acute kidney injury (CI-AKI; 2% vs. 15%; P = 0.001). The PCI success rate was similarly high (100% vs. 99%; P = 0.35). At 1 year (follow-up rate, 100%), we observed less induction of renal replacement therapy (RRT; 2.7% vs. 13.6%; P = 0.01), but all-cause mortality or myocardial infarction was similar in both groups. The IVUS-guided MINICON PCI reduces CI-AKI significantly and induction of RRT at 1 year in patients with stage 4 or 5 advanced CKD.

Altered interaction between plasminogen activator inhibitor type 1 activity and sympathetic nerve activity with aging.

BACKGROUND: It has been reported that sympathetic nerve activity (SNA) is associated with fibrinolysis, but the interaction between SNA and the fibrinolytic system with aging has not been elucidated in humans. The purpose of this study was to examine the effect of age-related SNA on the activity of plasminogen activator inhibitor type 1 (PAI-1) and tissue plasminogen activator (tPA) using muscle SNA (MSNA). METHODS AND RESULTS: This study included 16 young subjects (mean age 26.1 years) and 10 aged subjects (mean age 56.9 years). Lower body negative pressure (LBNP) was performed at -40 mmHg for 30 min. LBNP significantly increased both tPA and PAI-1 activity (from 5.2+/-0.5 to 7.3+/-1.2 IU/ml and from 2.85+/-0.68 to 4.06+/-0.73 U/ml, p<0.01, respectively) in the aged group. In the young group, tPA activity tended to increase, whereas PAI-1 activity was unchanged. There was a correlation between MSNA and PAI-1 activity in the aged group (r=0.47, p<0.01). CONCLUSIONS: SNA in an aging subject leads to an increase in the activity of PAI-1, which indicates that an altered interaction between SNA and PAI-1 activity contributes to increased cardiovascular events in the elderly population.

The activity of a single muscle sympathetic vasoconstrictor nerve unit is affected by physiological stress in humans.

Recording of neural firing from single-unit muscle sympathetic nerve activity (MSNA) is a new strategy offering information about the frequency of pure sympathetic firing. However, it is uncertain whether and when single-unit MSNA would be more useful than multiunit MSNA for analysis of various physiological stresses in humans. In 15 healthy subjects, we measured single-unit and multiunit MSNA before and during handgrip exercise at 30% of maximum voluntary contraction for 3 min and during the Valsalva maneuver at 40 mmHg expiratory pressure for 15 s. Shapes of individual single-unit MSNA were proved to be consistent and suitable for further evaluation. Single-unit and multiunit MSNA exhibited similar responses during handgrip exercise. However, acceleration of neural firing determined from single-unit MSNA became steeper than multiunit MSNA during the Valsalva maneuver. During the Valsalva maneuver, unlike handgrip exercise, the distribution of multiunit burst between 0, 1, 2, 3, and 4 spikes was significantly shifted toward multiple spikes within a given burst (P < 0.05). These results indicated that evaluation of single-unit MSNA could provide more detailed and accurate information concerning the role and responses of neuronal discharges induced by various physiological stresses in humans, especially amid intense sympathetic activity.