scholarly journals Relationship Between Fractionated Signal Areas in the Atrial Muscle During Sinus Rhythm and Atrial Pacing and Non-Pulmonary Vein Foci

Author(s):  
Jun Hirokami ◽  
Kenichi Hiroshima ◽  
Kyohei Yamaji ◽  
Kengo Korai ◽  
Michio Nagashima ◽  
...  
Author(s):  
Husam H. Balkhy ◽  
Margot E. Vloka ◽  
Peter D. Chapman ◽  
Christopher C. Peters

Objective Recent trials show that in patients with atrial fibrillation (AF), pulmonary vein isolation performed with bipolar surgical ablation clamps using small bilateral thoracotomies is more effective than pulmonary vein isolation using standard catheter ablation. This improved efficacy comes with higher invasiveness including difficulty in execution and potentially more acute complications. Monopolar “loop” devices overcome these drawbacks but at the potential cost of decreased efficacy. Technology that has bipolar effectiveness but with improved access and safety profiles, capable of being deployed endoscopically on a beating heart, would be desirable. We evaluated an ablation system that may have all of these characteristics. Methods Between May 2012 and May 2013, 30 patients were treated surgically for AF using a right-sided endoscopic approach with robotic assistance. In each patient, a “box” ablation lesion set was created around all pulmonary veins with a new linear suction-applied dual-mode (monopolar and bipolar) radiofrequency (RF) ablation device that was looped around the pulmonary veins. Temperature-controlled RF was applied for 60 seconds, with a set temperature of 70°C, first in the bipolar mode and then in a separate RF ablation for 60 seconds at 70°C in the monopolar mode. Acute effectiveness of the procedure was assessed using conduction block testing and by attempting to induce sustained AF with rapid atrial pacing. The left atrial appendage (LAA) was occluded in all patients with multiple ENDOLOOP snares using a left video-assisted thoracoscopic surgery approach under transesophageal echocardiography guidance, after which the tip of the LAA was incised to empty the LAA of blood. All patients were seen clinically at 30, 90, and 180 days with routine electrocardiography monitoring: at 6 months, 24-hour Holter monitoring was performed. Results Acute conduction block was achieved in 93% the of patients, and sustained AF could not be induced by rapid atrial pacing after the surgical ablation procedure in 90% of the patients. At 3- and 6-month follow-up, 88% and 81% of the patients, respectively, were in sinus rhythm. Of 16 the patients seen at 12-month follow-up, 14 (88%) were in sinus rhythm with 44% still on antiarrhythmic medications. Conclusions The newly introduced bipolar/monopolar RF ablation device can be easily positioned using a right endoscopic approach. Robotic assistance enables effective fat removal for accurate and easy placement of the device around the pulmonary veins. With the use of this approach, the device is safe and effective in electrically isolating the pulmonary veins.


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
O Yasin ◽  
A Sugrue ◽  
M Van Zyl ◽  
A Ladejobi ◽  
J Tri ◽  
...  

Abstract Background Slowing electrical conduction by cooling the myocardium can be used for defibrillation. We previously demonstrated the efficacy of a small cold device placed in oblique sinus (OS) in terminating atrial fibrillation (AF). However, the parameters needed to achieve effective atrial defibrillation are unknown. Purpose Assess effect of the size of cooled myocardium on frequency of AF termination in acute canine animal models. Methods Sternotomy was performed under general anesthesia in 10 acute canine experiments. AF was induced using rapid atrial pacing and intra-myocardial epinephrine and acetylcholine injections. Once AF sustained for at least 30s, either a cool (7–9°C) or placebo (body temperature) device was placed in the OS. Four device sizes were tested; ½X½, ¾X¾, and 1X1 inch devices and two ¾X¾ inch devices placed side by side simultaneously. Time to AF termination was recorded. Chi-squared or Fisher's exact test were used to compare the frequency of arrhythmia termination with cooling versus placebo. Results A total of 166 applications were performed (89 cool vs 77 placebo) in 10 animal experiments. Overall, AF terminated in 82% of the cooling applications vs. 67.5% of placebo (P=0.03, Figure 1). For the ½X½ inch device 88% of cold applications restored sinus rhythm vs. 63.6% for placebo (P=0.05). The frequency of sinus restoration for cold ¾X¾, 1X1 and two ¾X¾ side by side devices was 86.7%, 83.3% and 70% respectively. Time to sinus restoration when achieved was within three minutes was also not significantly changed. Conclusion Placing a cool device in the oblique sinus can terminate AF and efficacy is not affected by the size of device. Funding Acknowledgement Type of funding source: Private grant(s) and/or Sponsorship. Main funding source(s): MediCool Technologies


2020 ◽  
Vol 41 (Supplement_2) ◽  
Author(s):  
N Harlaar ◽  
M.A.P Oudeman ◽  
S.A Trines ◽  
G.S De Ruiter ◽  
M Khan ◽  
...  

Abstract Background Catheter ablation in patients with long-standing persistent AF (LSPAF) remains challenging and often requires repeated procedures with variable results. We report long-term outcomes of a bipolar thoracoscopic pulmonary vein and left atrial posterior wall ablation for LSPAF, and compare continuous and interval rhythm monitoring. Methods Seventy-seven LSPAF patients who underwent thoracoscopic pulmonary vein and box isolation between 2009–2017 in two Dutch centers were included. Follow-up consisted of continuous rhythm monitoring using an implanted loop recorder or 24-h Holter at 3/6/12/24/60 months. Results Mean age was 59±8 years with a median AF duration of 3.8 [1.2–6.3] years. In the total cohort, at 2-year follow-up, 86.0% of patients were in sinus rhythm, 12.3% were in paroxysmal AF and 1.6% in persistent AF. At 5 years, 62.9% of patients were in sinus rhythm, 20.0% in paroxysmal AF, 14.3% in persistent AF and 2.9% was experiencing atrial flutter. Continuous rhythm monitoring was performed in 46% of patients. Comparing continuous and interval rhythm monitoring, freedom from any atrial arrhythmia episode at 2- and 5 years was 60.0% and 49.9% in the continuous group and 93.8% and 51.9% in the interval monitoring group, respectively (p=0.02, Breslow-Wilcoxon test). In patients with continuous rhythm monitoring the mean atrial arrhythmia burden was reduced from 99.1% preoperatively to 0.1% at the end of the blanking period and 7.3% at 2-year follow-up. Conclusions Thoracoscopic box ablation is highly effective in restoring sinus rhythm at medium term follow-up. However, it is not a curative treatment as demonstrated by the 50% arrhythmia-free survival at long-term follow-up. Whether this is due to the progressive nature of AF needs further investigation. Continuous rhythm monitoring shows earlier recurrence detection with a potential early treatment adaptation. Funding Acknowledgement Type of funding source: None


Author(s):  
Martin Eichenlaub ◽  
Bjoern Mueller-Edenborn ◽  
Jan Minners ◽  
Martin Allgeier ◽  
Heiko Lehrmann ◽  
...  

Abstract Background Relevant atrial cardiomyopathy (ACM), defined as a left atrial (LA) low-voltage area ≥ 2 cm2 at 0.5 mV threshold on endocardial contact mapping, is associated with new-onset atrial fibrillation (AF), higher arrhythmia recurrence rates after pulmonary vein isolation (PVI), and an increased risk of stroke. The current study aimed to assess two non-invasive echocardiographic parameters, LA emptying fraction (EF) and LA longitudinal strain (LAS, during reservoir (LASr), conduit (LAScd) and contraction phase (LASct)) for the diagnosis of ACM and prediction of arrhythmia outcome after PVI. Methods We prospectively enrolled 60 consecutive, ablation-naive patients (age 66 ± 9 years, 80% males) with persistent AF. In 30 patients (derivation cohort), LA-EF and LAS cut-off values for the presence of relevant ACM (high-density endocardial contact mapping in sinus rhythm prior to PVI at 3000 ± 1249 sites) were established in sinus rhythm and tested in a validation cohort (n = 30). Arrhythmia recurrence within 12 months was documented using 72-h Holter electrocardiograms. Results An LA-EF of < 34% predicted ACM with an area under the curve (AUC) of 0.846 (sensitivity 69.2%, specificity 76.5%) similar to a LASr < 23.5% (AUC 0.878, sensitivity 92.3%, specificity 82.4%). In the validation cohort, these cut-offs established the correct diagnosis of ACM in 76% of patients (positive predictive values 87%/93% and negative predictive values 73%/75%, respectively). Arrhythmia recurrence in the entire cohort was significantly more frequent in patients with LA-EF < 34% and LASr < 23.5% (56% vs. 29% and 55% vs. 26%, both p < 0.05). Conclusion The echocardiographic parameters LA-EF and LAS allow accurate, non-invasive diagnosis of ACM and prediction of arrhythmia recurrence after PVI. Graphic abstract


2020 ◽  
Vol 9 (17) ◽  
Author(s):  
Daniel N. Silverman ◽  
Mehdi Rambod ◽  
Daniel L. Lustgarten ◽  
Robert Lobel ◽  
Martin M. LeWinter ◽  
...  

Background Increases in heart rate are thought to result in incomplete left ventricular (LV) relaxation and elevated filling pressures in patients with heart failure with preserved ejection fraction (HFpEF). Experimental studies in isolated human myocardium have suggested that incomplete relaxation is a result of cellular Ca 2+ overload caused by increased myocardial Na + levels. We tested these heart rate paradigms in patients with HFpEF and referent controls without hypertension. Methods and Results In 22 fully sedated and instrumented patients (12 controls and 10 patients with HFpEF) in sinus rhythm with a preserved ejection fraction (≥50%) we assessed left‐sided filling pressures and volumes in sinus rhythm and with atrial pacing (95 beats per minute and 125 beats per minute) before atrial fibrillation ablation. Coronary sinus blood samples and flow measurements were also obtained. Seven women and 15 men were studied (aged 59±10 years, ejection fraction 61%±4%). Patients with HFpEF had a history of hypertension, dyspnea on exertion, concentric LV remodeling and a dilated left atrium, whereas controls did not. Pacing at 125 beats per minute lowered the mean LV end‐diastolic pressure in both groups (controls −4.3±4.1 mm Hg versus patients with HFpEF −8.5±6.0 mm Hg, P =0.08). Pacing also reduced LV end‐diastolic volumes. The volume loss was about twice as much in the HFpEF group (controls −15%±14% versus patients with HFpEF −32%±11%, P =0.009). Coronary venous [Ca 2+ ] increased after pacing at 125 beats per minute in patients with HFpEF but not in controls. [Na + ] did not change. Conclusions Higher resting heart rates are associated with lower filling pressures in patients with and without HFpEF. Incomplete relaxation and LV filling at high heart rates lead to a reduction in LV volumes that is more pronounced in patients with HFpEF and may be associated with myocardial Ca 2+ retention.


2013 ◽  
Vol 106 (10) ◽  
pp. 501-510 ◽  
Author(s):  
Frederic A. Sebag ◽  
Najia Chaachoui ◽  
Nick W. Linton ◽  
Sana Amraoui ◽  
James Harrison ◽  
...  

2018 ◽  
Vol 4 (11) ◽  
pp. 553-555
Author(s):  
Marina Arai ◽  
Seiji Fukamizu ◽  
Rintaro Hojo ◽  
Masayasu Hiraoka

2004 ◽  
Vol 286 (6) ◽  
pp. H2072-H2077 ◽  
Author(s):  
Angela M. Park ◽  
Chung-Chuan Chou ◽  
Paul C. Drury ◽  
Yuji Okuyama ◽  
Anish Peter ◽  
...  

The thoracic vein hypothesis of chronic atrial fibrillation (AF) posits that rapid, repetitive activations from muscle sleeves within thoracic veins underlie the mechanism of sustained AF. If this is so, thoracic vein ablation should terminate sustained AF and prevent its reinduction. Six female mongrel dogs underwent chronic pulmonary vein (PV) pacing at 20 Hz to induce sustained (>48 h) AF. Bipolar electrodes were used to record from the atria and thoracic veins, including the vein of Marshall, four PVs, and the superior vena cava. Radio frequency (RF) application was applied around the PVs and superior vena cava and along the vein of Marshall until electrical activity was eliminated. Computerized mapping (1,792 electrodes, 1 mm resolution) was also performed. Sustained AF was induced in 30.6 ± 6.5 days, and ablation was done 17.3 ± 8.5 days afterward. Before ablation, the PVs had shorter activation cycle lengths than the atria, and rapid, repetitive activations were observed in the PVs. All dogs converted to sinus rhythm during ( n = 4 dogs) or within 90 min of completion of RF ablation. Rapid atrial pacing afterward induced only nonsustained (<60 s) AF in all dogs. Average AF cycle lengths after reinduction were significantly ( P = 0.01) longer (183 ± 31.5 ms) than baseline (106 ± 16.2 ms). There were no activation cycle length gradients after RF application. We conclude that thoracic vein ablation converts canine sustained AF into sinus rhythm and prevents the reinduction of sustained AF. These findings suggest that thoracic veins are important in the maintenance of AF in dogs.


Open Heart ◽  
2021 ◽  
Vol 8 (2) ◽  
pp. e001718
Author(s):  
Bart A Mulder ◽  
Meelad I H Al-Jazairi ◽  
Federico T Magni ◽  
Hessel F Groenveld ◽  
Robert G Tieleman ◽  
...  

IntroductionPulmonary vein isolation (PVI) is an important treatment for atrial fibrillation (AF). However, many patients need more than one procedure to maintain long-term sinus rhythm. Even after two PVIs some may suffer from AF recurrences. We aimed to identify characteristics of patients who fail after two PVI procedures.Methods and resultsWe included 557 consecutive patients undergoing a first PVI procedure with a second-generation 28 mm cryoballoon. Follow-up procedures were performed using radiofrequency ablation targeting reconnected PVs only. Recurrent AF was defined as any episode of AF lasting >30 s on ECG or 24 hour Holter monitoring performed at 3, 6 and 12 months post procedure. Mean age was 59.1±10.2 years, 383 (68.8%) were male, 448 (80.4%) had paroxysmal AF and the most common underlying condition was hypertension (36.6%). A total of 140/557 (25.1%) patients underwent redo procedure with PVI only. Of these patients 45 (32.4%) had recurrence of AF. These patients were comparable regarding age and sex to those in sinus rhythm after one or two procedures. Multivariate logistic regression showed that non-paroxysmal AF (OR 1.08 (95% CI 1.01 to 1.15), estimated glomerular filtration rate (OR 0.96, 95% CI 0.94 to 0.99), bundle branch block (OR 4.17, 95% CI 1.38 to 12.58), heart failure (OR 4.17, 95% CI 1.38 to 12.58) and Left Atrium Volume Index (OR 1.04, 95% CI 1.01 to 1.08) were associated with AF recurrence after two PVIs. The area under the curve for the identified risk factors was 0.74.ConclusionsUsing a PVI-only approach, recurrence of AF after two AF ablation procedures is associated with more advanced underlying disease and persistent types of AF.


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