Demonstration of an adjacent conduction gaps-derived left atrial and pulmonary vein flutter by high-density mapping

A useful reassuring sign for performing a safe second transseptal puncture

Radiotherapy for patients with cardiovascular implantable electronic devices: an 11-year experience Abstract Purpose As cardiovascular implantable electronic devices (CIEDs) are increasingly indicated in older patients, and the burden of cancer is rising with the aging population, the management of patients with CIEDs who require radiotherapy (RT) is a timely concern. The objective of the study was to evaluate the management of, and malfunctions in, patients with CIEDs undergoing RT. Methods A retrospective study of patients with CIEDs receiving RT at Kingston Health Sciences Center from March 2007–April 2018 was conducted. Data on demographics, RT, devices, and management were compared for the primary outcome of device malfunction. Results Of the 189 patients with CIEDs receiving a total of 297 courses of RT, 4 patients (2.1%) experienced device malfunctions. Higher beam energy was associated with a malfunction (p < 0.05). Patients with malfunctions received a lower dose of radiation per fraction (267 ± 93 cGy vs. 477 ± 282 cGy; p < 0.05) and were significantly younger (71.4 ± 2.2 years vs. 77.8 ± 9.8 years; p < 0.01) compared to patients without malfunctions. Conclusion RT-induced device malfunctions are rare, but given the potential complications, a better understanding of the potential predictors of malfunction and the development of evidence-based guidelines will help optimize patient safety.

Long-term performance of right ventricular pacing leads: risk factors associated with permanent right ventricular pacing threshold increase Abstract Purpose Right ventricular pacing threshold (RVPT) may rise over time accompanied by the increased use of implantable cardiac pacemakers. However, risk factors for permanent RVPT increase are not fully clarified in patients without definite lead fracture and dislodgment. We aimed to evaluate the long-term performance of RV pacing leads and identify risk factors associated with the occurrence of permanent RVPT increase in this population. Methods Patients with first implantation of cardiac pacemakers from January 2008 to June 2016 were consecutively enrolled. Follow-up for RVPT increase was until December 2017. The clinical data, specific data on the pacemaker implantation, and routine follow-up were retrieved. Results During a follow-up duration of 5.4 ± 2.1 years, permanent RVPT increase (except lead fracture and dislodgment) was found in 8.4% (87/1033) patients. Patients with permanent RVPT increase had higher prevalence of myocardial infarction (MI), diabetes, and the use of amiodarone. The risk factors independently associated with permanent RVPT increase were MI (HR = 1.094, 95% CI 1.014–1.180, p = 0.031), diabetes (HR = 2.804, 95% CI 1.064–3.775, p = 0.003). MI patients with RVPT increase had higher prevalence of multivessel disease and atrioventricular block. Diabetic patients with RVPT increase exhibited higher serum fasting blood glucose (FBG) and hemoglobin A1c (HbA1c) levels, which were correlated with the maximum RVPT (p < 0.001). Conclusions Our data showed that permanent RVPT increases (except lead fracture and dislodgement) during long-term follow-up after pacemaker implantation. The likely risk factors predisposing to chronic permanent RVPT increase are MI and diabetes with higher FBG and HbA1c levels.

The modified ablation index: a novel determinant of acute pulmonary vein reconnections after pulmonary vein isolation Abstract Background Although pulmonary vein isolation (PVI) guided by the ablation index (AI) has been well-developed, acute PV reconnections (PVRs) still occur. This study aimed to compare the prognostic performance of the modified AI and its optimal cut-off value for the prediction of acute PVRs to ensure durable PVI. Methods Three-dimensional left atrium (LA) voltage maps created before an extensive encircling PVI in 64 patients with atrial fibrillation (AF) (45 men, 62 ± 10 years) were examined for an association between electrogram voltage amplitude recorded from the PV–LA junction and acute post-PVI PVRs (spontaneous PVRs and/or ATP-provoked dormant PV conduction). Results Acute PVRs were observed in 22 patients (34%) and 33 (3%) of the 1012 PV segments. Acute PVRs were significantly associated with segments with higher bipolar voltage zones (3.23 ± 1.17 vs. 1.97 ± 1.20 mV, P < 0.0001), lower mean AI values (449 [428–450] vs. 460 [437–486], P = 0.05), and radiofrequency lesion gaps ≥ 6 mm (48 vs. 32%, P = 0.04), but not with contact force, force–time integral, or power. We created the modified AI calculated as AI/LA bipolar voltage, and found it to be significantly lower in areas with acute PVRs than in those without (152 [109–185] vs. 256 [176–413] AU/mV, P < 0.0001). Univariate analysis showed the prognostic performance of the modified AI, with an area under the curve of 0.801 (0.775–0.825), to be the highest of all the significant parameters. Conclusions Low values of the novel modified AI on the PV-encircling ablation line were strongly associated with acute PVRs.

Irreversible electroporation for catheter-based cardiac ablation: a systematic review of the preclinical experience Abstract Introduction Irreversible electroporation (IRE) utilizing high voltage pulses is an emerging strategy for catheter-based cardiac ablation with considerable growth in the preclinical arena. Methods A systematic search for articles was performed from three sources (PubMed, EMBASE, and Google Scholar). The primary outcome was the efficacy of tissue ablation with characteristics of lesion formation evaluated by histologic analysis. The secondary outcome was focused on safety and damage to collateral structures. Results Sixteen studies met inclusion criteria. IRE was most commonly applied to the ventricular myocardium (n = 7/16, 44%) by a LifePak 9 Defibrillator (n = 9/16, 56%), NanoKnife Generator (n = 2/16, 13%), or other custom generators (n = 5/16, 31%). There was significant heterogeneity regarding electroporation protocols. On histological analysis, IRE was successful in creating ablation lesions with variable transmurality depending on the electric pulse parameters and catheter used. Conclusion Preclinical studies suggest that cardiac tissue ablation using IRE shows promise in delivering efficacious, safe lesions.

Heart failure progression and mortality in atrial fibrillation patients with preserved or reduced left ventricular ejection fraction Abstract Background Atrial fibrillation (AF) worsens cardiovascular (CV) outcomes of heart failure (HF) and vice versa. The impact of rate or rhythm control strategies on HF progression and survival remains unclear. Methods We examined the risk of HF progression in AF patients (pts) with a prior HF event and minimal or no HF burden (NYHA class 0 or 1). They were stratified into HF with a preserved left ventricular ejection fraction (≥ 40%, pEF) or reduced EF (< 40%, rEF). HF subgroups from the Rate and Rhythm arm were compared for the primary outcome of worsening HF or death (WHFD), total mortality, cardiovascular mortality, and cardiovascular hospitalizations. Results Four hundred ninety-two AF pts (HFpEF = 349, HFrEF = 143) were analyzed. Baseline characteristics were generally comparable in the Rate and Rhythm arms of the two subgroups. Over a median follow-up of 4 years, HF recurred and worsened in 66.6% and 41.2% of pts by ≥ 1 and ≥ 2 NYHA classes, respectively. HF progression by even 1 NYHA class increased the mortality risk in HFpEF (hazard ratio (HR) 2.06; 95% confidence intervals (CI) 1.25–3.4; p = 0.004) and HFrEF (HR 1.9; 95% CI 0.99–3.66; p = 0.054). Cardiovascular hospitalization (CVH) increased in HFpEF (HR 3.67; 95% CI 2.56, 5.25; p < 0.0001) and HFrEF (HR 2.8; 95% CI 1.53–5.14; p = 0.0009). HF progression by 2 or more NYHA classes or death was significantly worse in pts with HFrEF with the Rate control strategy compared with the Rhythm control (HR 1.62; 95% CI 1.03–2.53; p = 0.036) but similar in pts with HFpEF (HR 0.88; 95% CI 0.64–1.21; p = 0.440).The time to first AF recurrence was longer in the Rhythm arms of both HF subgroups as compared with Rate (Figure, p < 0.05). Conclusions (1) HF progression in AF pts with a prior HF event confers significant mortality and CVH risk in both HFrEF and HFpEF populations. (2) HF progression is more pronounced with a Rate control strategy in AF pts with HFrEF, but is comparable to Rhythm control in AF pts with HFpEF. (3) A Rhythm control strategy may be desirable to reduce HF progression in pts with HFrEF and AF. Prospective clinical trials appear warranted to examine HF progression by treatment strategy in HFpEF and HFrEF populations with AF.

Effect of early pendulum exercise on shoulder function after cardiac rhythm management device implantation Abstract Purpose Patients who are post-implantation of cardiac rhythm management devices (CRMDs) are commonly instructed to restrict ipsilateral arm movement to reduce risk of lead dislodgement. This immobilization practice increases risk of shoulder-related pain leading to limited shoulder function. We aimed to assess effect of pendulum exercise on shoulder function in patients after CRMD implantation. Methods This study was a prospective, randomized, open-blinded end point study conducted with 200 patients undergoing CRMD implantation. They were randomized into two groups, standard care (control) and pendulum exercise (experimental) groups. The shoulder function was assessed using QuickDASH-TH scores and measurement of the range of motion (ROM) of shoulder abduction and flexion before and 1 month after implantation. Results Baseline characteristics did not differ between the two groups. The lower incidence of shoulder ROM reduction after CRMD implantation was demonstrated in the pendulum exercise group compared to the control group in both flexion (16.8% vs. 40.4%, P < 0.001) and abduction (9.9% vs. 32.3%, P < 0.001). A lower disability of shoulder function after implantation assessed by QuickDASH-TH scores was also noted in the exercise group compared to control (15.2 ± 16.4 vs. 23.4 ± 18.1, P = 0.001). Two patients in the control group and one in the exercise group had atrial lead dislodgement on the day following the procedure. Conclusions Early pendulum exercise with ipsilateral arm after CRMD implantation was safe and resulted in lower incidence of limited shoulder ROM and less disability of shoulder function compared to control group. Trial registration The study was registered in clinicaltrials.in.th, and the identification number is TCTR20180612003.

Cryoballoon ablation of atrial fibrillation is effectively feasible without previous imaging of pulmonary vein anatomy: insights from the 1STOP project Abstract Background Pulmonary vein isolation by cryoablation (PVI-C) is a standard therapy for the treatment of atrial fibrillation (AF); however, PVI-C can become a challenging procedure due to the anatomy of the left atrium and pulmonary veins (PVs). Importantly, the utility of imaging before the procedure is still unknown regarding the long-term clinical outcomes following PVI-C. The aim of the analysis is to evaluate the impact of imaging before PVI-C on procedural data and AF recurrence. Methods Patients with paroxysmal AF underwent an index PVI-C. Data were collected prospectively in the framework of 1STOP ClinicalService® project. Patients were divided into two groups according to the utilization of pre-procedural imaging of PV anatomy (via CT or MRI) or the non-usage of pre-procedural imaging. Results Out of 912 patients, 461 (50.5%) were evaluated with CT or MRI before the PVI-C and denoted as the imaging group. Accordingly, 451 (49.5%) patients had no pre-procedural imaging and were categorized as the no imaging group. Patient baseline characteristics were comparable between the two cohorts, but the ablation centers that comprised the imaging group had fewer PVI-C cases per year than the no imaging group (p < 0.001). The procedure, fluoroscopy, and left atrial dwell times were significantly shorter in the no imaging cohort (p < 0.001). The rates of complications were significantly greater in the imaging group compared to the no imaging group (6.9% vs. 2.7%; p = 0.003); this difference was attributed to differences in transient diaphragmatic paralysis. The 12-month freedom from AF was 76.2% in the imaging group and 80.0% in the no imaging group (p = 0.390). Conclusions In our analysis, PVI-C was effective regardless of the availability of imaging data on PV anatomy.

Prognostic impact of left ventricular ejection fraction in patients with electrical storm Abstract Objectives The study sought to assess retrospectively the prognostic impact of left ventricular ejection fraction (LVEF) in patients with electrical storm (ES). Background Data regarding the prognostic impact of impaired LVEF in ES patients is rare. Methods Consecutive patients presenting with ES from 2002 to 2016 were included retrospectively. Patients with LVEF ≤ 35% were compared to patients with LVEF > 35%. The primary prognostic endpoint was long-term all-cause mortality, and secondary endpoints were rates of in-hospital mortality, rehospitalization, major adverse cardiac events (MACE), and ES recurrences (ES-R) at long-term follow-up. Results A total of 80 patients with ES were included at 2.5 years of follow-up. 69% of patients suffered from LVEF ≤ 35%. ES patients with LVEF ≤ 35% were associated with higher rates of the primary endpoint of all-cause mortality (53% versus 8%, log-rank p = 0.0001; HR 8.524; 95% CI 2.030–35.793, p = 0.003), as well as the secondary endpoints of MACE (53% versus 20%; log rank p = 0.011; HR 3.213, 95% CI 1.241–8.316, p = 0.016) and ES-R (35% versus 8%; log rank p = 0.019; HR 4.821, 95% CI 1.122–20.706, p = 0.034). Furthermore, ES patients with LVEF ≤ 35% showed higher rates of rehospitalization due to acute heart failure (24% versus 8%, statistical trend p = 0.096). Notably, ES patients with LVEF > 35% were associated with increased rates of rehospitalization due to ventricular tachycardia (36% versus 18%, statistical trend p = 0.083). Conclusions ES patients with LVEF ≤ 35% were associated with increased rates of all-cause mortality, MACE, ES-R and heart failure-related rehospitalization at long-term follow-up. Condensed abstract This study evaluated retrospectively the prognostic impact of LVEF in patients with ES. LVEF ≤ 35% was associated with increased long-term all-cause mortality (53% versus 8%; HR 8.524; 95% CI 2.030–35.793, p = 0.003), MACE (53% versus 20%; HR 3.213, 95% CI 1.241–8.316, p = 0.016), and ES recurrences (35% versus 8%; HR 4.821, 95% CI 1.122–20.706, p = 0.034), while trends were observed for higher rates of heart-failure related rehospitalization (24% versus 8%, p = 0.096) and MACE (49% versus 28%; p = 0.081).