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JACC. Clinical Electrophysiology Apr 2023QDOT MICRO (QDM) is a novel contact force-sensing catheter optimized for temperature-controlled radiofrequency (RF) ablation. The very high-power short-duration (vHPSD)...
BACKGROUND
QDOT MICRO (QDM) is a novel contact force-sensing catheter optimized for temperature-controlled radiofrequency (RF) ablation. The very high-power short-duration (vHPSD) algorithm modulates power, maintaining target temperature during 90 W ablations for ≤4 seconds.
OBJECTIVES
This study aims to evaluate safety and 12-month effectiveness of the QDM catheter in paroxysmal atrial fibrillation (AF) ablation using the vHPSD mode combined with conventional-power temperature-controlled (CPTC) mode.
METHODS
In this prospective, multicenter, nonrandomized study, patients with drug-refractory, symptomatic paroxysmal AF underwent pulmonary vein (PV) isolation with QDM catheter with vHPSD as primary ablation mode, with optional use of the CPTC mode (25 to 50 W) for PV touch-up or non-PV ablation. The primary safety endpoint was incidence of primary adverse events within ≤7 days of ablation. The primary effectiveness endpoint was freedom from documented atrial tachyarrhythmia recurrence and acute procedural, repeat ablation, and antiarrhythmic drug failure.
RESULTS
Of 191 enrolled participants, 166 had the catheter inserted, received RF ablation, and met eligibility criteria. Median procedural, RF application for ablating PVs, and fluoroscopy times were 132.0, 8.0, and 9.1 minutes, respectively. The primary adverse event rate was 3.6%. Imaging conducted in a subset of participants (n = 40) at 3 months did not show moderate or severe PV stenosis. The Kaplan-Meier estimated 12-month rate for primary effectiveness success was 76.7%; freedom from atrial tachyarrhythmia recurrence was 82.1%; clinical success (freedom from symptomatic recurrence) was 86.0%; and freedom from repeat ablation was 92.1%.
CONCLUSIONS
Temperature-controlled paroxysmal AF ablation with the novel QDM catheter in vHPSD mode (90 W, ≤4 seconds), alone or with CPTC mode (25 to 50 W), is highly efficient and effective without compromising safety. (Evaluation of QDOT MICRO Catheter for Pulmonary Vein Isolation in Subjects With Paroxysmal Atrial Fibrillation [Q-FFICIENCY]; NCT03775512).
Topics: Humans; Atrial Fibrillation; Temperature; Prospective Studies; Treatment Outcome; Catheter Ablation; Radiofrequency Ablation
PubMed: 36752484
DOI: 10.1016/j.jacep.2022.10.019 -
Journal of Arrhythmia Jun 2021Coronary injury presenting as ST segment elevation (STE) during ablation procedures for different arrhythmias is a rare and most feared complication. There have been... (Review)
Review
Coronary injury presenting as ST segment elevation (STE) during ablation procedures for different arrhythmias is a rare and most feared complication. There have been multiple reports on STE during various ablation procedures in the recent past. Herein, we review various mechanisms, presentations, and management of STE observed during various ablations, including atrial fibrillation ablation cavotricuspid isthmus and ablation, supraventricular tachycardia ablations, coronary sinus ablation, and ventricular arrhythmia ablations.
PubMed: 34141005
DOI: 10.1002/joa3.12526 -
International Journal of Hyperthermia :... Oct 2019A growing body of evidence is being published regarding the safety and efficacy of minimally invasive image-guided ablation techniques. While clinical applications of... (Review)
Review
A growing body of evidence is being published regarding the safety and efficacy of minimally invasive image-guided ablation techniques. While clinical applications of these techniques are increasing, international societies have started to publish treatment guidelines and to make efforts to standardize both terminology and reporting criteria for image-guided thyroid ablations. Laser ablation and radiofrequency ablation (RFA) are among the most common ablation techniques either for benign and malignant thyroid nodules. Unlike laser ablation and RFA in the treatment of benign thyroid nodules, where safety and efficacy have been widely demonstrated, evidence regarding local tumor control of thyroid malignancies is still limited. However, preliminary results are encouraging and image-guided thermal ablation techniques can be considered a valid alternative to surgery for the treatment of benign thyroid nodules and recurrent thyroid cancers. This review evaluates the basic concept of RFA and laser ablations, their techniques, clinical outcomes, and complications based on the suggestions of several society guidelines. Multidisciplinary collaboration remains critical to identify patients which may benefit from minimally invasive image-guided thermal ablations, especially if surgery or radioiodine therapy are not feasible options.
Topics: Catheter Ablation; Humans; Laser Therapy; Thyroid Neoplasms; Treatment Outcome
PubMed: 31537159
DOI: 10.1080/02656736.2019.1622795 -
International Journal of Hyperthermia :... Dec 2017Papillary thyroid carcinoma (PTC) is the most common subtype of thyroid malignancy and has a good prognosis and low mortality rate. Surgery is the standard treatment for... (Review)
Review
Papillary thyroid carcinoma (PTC) is the most common subtype of thyroid malignancy and has a good prognosis and low mortality rate. Surgery is the standard treatment for patients with primary and recurrent thyroid cancer. Although patients with PTC usually exhibit excellent treatment outcome, the incidence of recurrence in the neck ranges from 20% to 59%. When a patient with thyroid cancer is contraindicated for surgery, ultrasound (US)-guided ablation techniques, including ethanol ablation (EA) and thermal ablations, are suggested alternatives. In this review, we evaluated the indications, devices, techniques, clinical outcomes, and complications associated with US-guided EA and thermal ablations based on available scientific evidence and expert opinions regarding the use of ablation for primary and recurrent thyroid cancers.
Topics: Ablation Techniques; Ethanol; Humans; Thyroid Neoplasms
PubMed: 28797186
DOI: 10.1080/02656736.2017.1361048 -
Arrhythmia & Electrophysiology Review Aug 2018Techniques to ablate persistent atrial fibrillation (AF) continue to evolve. Recent technological and strategic innovations have included a focus on mapping and ablating... (Review)
Review
Techniques to ablate persistent atrial fibrillation (AF) continue to evolve. Recent technological and strategic innovations have included a focus on mapping and ablating AF sources. These attempts have not yet yielded a consistent improvement in clinical outcomes following AF ablation. Advancements in these techniques in the next few years, however, may enhance our ability to map and ablate AF as well as further our understanding of the mechanisms behind AF initiation, perpetuation, and recurrence.
PubMed: 30416729
DOI: 10.15420/aer:2018:25:2 -
International Journal of Cardiology.... Sep 2015In light of recent reports showing high incidence of silent cerebral infarcts and organized atrial arrhythmias following radiofrequency (RF) atrial fibrillation (AF)... (Review)
Review
In light of recent reports showing high incidence of silent cerebral infarcts and organized atrial arrhythmias following radiofrequency (RF) atrial fibrillation (AF) ablation, a review of its safety aspects is timely. Serious complications do occur during supraventricular tachycardia (SVT) ablations and knowledge of their incidence is important when deciding whether to proceed with ablation. Evidence is emerging for the probable role of prophylactic ischemic scar ablation to prevent VT. This might increase the number of procedures performed. Here we look at the various complications of RF ablation and also the methods to minimize them. Electronic database was searched for relevant articles from 1990 to 2015. With better awareness and technological advancements in RF ablation the incidence of complications has improved considerably. In AF ablation it has decreased from 6% to less than 4% comprising of vascular complications, cardiac tamponade, stroke, phrenic nerve injury, pulmonary vein stenosis, atrio-esophageal fistula (AEF) and death. Safety of SVT ablation has also improved with less than 1% incidence of AV node injury in AVNRT ablation. In VT ablation the incidence of major complications was 5-11%, up to 3.4%, up to 1.8% and 4.1-8.8% in patients with structural heart disease, without structural heart disease, prophylactic ablations and epicardial ablations respectively. Vascular and pericardial complications dominated endocardial and epicardial VT ablations respectively. Up to 3% mortality and similar rates of tamponade were reported in endocardial VT ablation. Recent reports about the high incidence of asymptomatic cerebral embolism during AF ablation are concerning, warranting more research into its etiology and prevention.
PubMed: 28785694
DOI: 10.1016/j.ijcha.2015.04.011 -
The Journal of Innovations in Cardiac... Jun 2018Catheter ablation is widely utilized for the management of atrial fibrillation (AF), particularly in patients who are refractory to medical therapy. The left atrium... (Review)
Review
Catheter ablation is widely utilized for the management of atrial fibrillation (AF), particularly in patients who are refractory to medical therapy. The left atrium appears to play a dominant role in the condition of most patients with AF and, in particular, the posterior wall and pulmonary veins frequently harbor sources of fibrillation. Currently, the role of posterior wall isolation during catheter ablation of AF is controversial. In this review, we will examine the mechanistic role of the posterior left atrium, discuss the technical challenges of ablating in the posterior wall and the evolution of strategies to achieve isolation with catheter approaches, and review the relevant literature to date.
PubMed: 32477812
DOI: 10.19102/icrm.2018.090602 -
World Journal of Gastrointestinal... Feb 2019Malignant biliary strictures are usually linked to different types of tumors, mainly cholangiocarcinoma, pancreatic and hepatocellular carcinomas. Palliative measures... (Review)
Review
Malignant biliary strictures are usually linked to different types of tumors, mainly cholangiocarcinoma, pancreatic and hepatocellular carcinomas. Palliative measures are usually adopted in patients with nonresectable or borderline resectable biliary disease. Stent placement is a well-known and established treatment in patients with unresectable malignancy. Intraductal radiofrequency ablation (RFA) represents a procedure that involves the use of a biliary catheter device, an endoscopic approach. Indications for biliary RFA described in literature are: Palliative treatment of malignant biliary strictures, avoiding stent occlusion, ablating ingrowth of blocked metal stents, prolonging stent patency, ablating residual adenomatous tissue after endoscopic ampullectomy. In this mini-review we addressed focus on technical success defined as deployment of the RF catheter, virtually succeeded in all patients included in the studies. About efficacy, three main outcome measures have been contemplated: Biliary decompression and stent patency, survival. Existing studies suggest a beneficial effect on survival and stent patency with RFA, but current impression is limited because most of studies have been performed using a retrospective design, on diminutive and dissimilar cohorts of patients.
PubMed: 30788028
DOI: 10.4253/wjge.v11.i2.95 -
IEEE Transactions on Ultrasonics,... Sep 2021A 34-mm aperture transducer was designed and tested for proof of concept to ablate tissues using an endocavity histotripsy device. Several materials and two drivers were...
A 34-mm aperture transducer was designed and tested for proof of concept to ablate tissues using an endocavity histotripsy device. Several materials and two drivers were modeled and tested to determine an effective piezoelectric-matching layer combination and driver design. The resulting transducer was fabricated using 1.5 MHz porous PZT and PerFORM 3-D printed acoustic lenses and was driven with a multicycle class-D amplifier. The lower frequency, compared to previously developed small form factor histotripsy transducers, was selected to allow for more efficient volume ablation of tissue. The transducer was characterized and tested by measuring pressure field maps in the axial and lateral planes and pressure output as a function of driving voltage. The axial and lateral full-width-half-maximums of the focus were found to be 6.1 and 1.1 mm, respectively. The transducer was estimated to generate 34.5-MPa peak negative focal pressure with a peak-to-peak driving voltage of 1345 V. Performance testing was done by ablating volumes of bovine liver tissues ( n = 3 ). The transducer was found to be capable of ablating tissues at its full working distance of 17 mm.
Topics: Acoustics; Animals; Cattle; Equipment Design; High-Intensity Focused Ultrasound Ablation; Liver; Transducers
PubMed: 33507869
DOI: 10.1109/TUFFC.2021.3055138 -
Cardiovascular Research Jun 2021Modern cardiac electrophysiology has reported significant advances in the understanding of mechanisms underlying complex wave propagation patterns during atrial... (Review)
Review
Modern cardiac electrophysiology has reported significant advances in the understanding of mechanisms underlying complex wave propagation patterns during atrial fibrillation (AF), although disagreements remain. One school of thought adheres to the long-held postulate that AF is the result of randomly propagating wavelets that wonder throughout the atria. Another school supports the notion that AF is deterministic in that it depends on a small number of high-frequency rotors generating three-dimensional scroll waves that propagate throughout the atria. The spiralling waves are thought to interact with anatomic and functional obstacles, leading to fragmentation and new wavelet formation associated with the irregular activation patterns documented on AF tracings. The deterministic hypothesis is consistent with demonstrable hierarchical gradients of activation frequency and AF termination on ablation at specific (non-random) atrial regions. During the last decade, data from realistic animal models and pilot clinical series have triggered a new era of novel methodologies to identify and ablate AF drivers outside the pulmonary veins. New generation electroanatomical mapping systems and multielectrode mapping catheters, complimented by powerful mathematical analyses, have generated the necessary platforms and tools for moving these approaches into clinical procedures. Recent clinical data using such platforms have provided encouraging evidence supporting the feasibility of targeting and effectively ablating driver regions in addition to pulmonary vein isolation in persistent AF. Here, we review state-of-the-art technologies and provide a comprehensive historical perspective, characterization, classification, and expected outcomes of current mechanism-based methods for AF ablation. We discuss also the challenges and expected future directions that scientists and clinicians will face in their efforts to understand AF dynamics and successfully implement any novel method into regular clinical practice.
Topics: Action Potentials; Animals; Atrial Fibrillation; Catheter Ablation; Heart Atria; Heart Rate; Humans; Recurrence; Treatment Outcome
PubMed: 33744913
DOI: 10.1093/cvr/cvab108