Radiofrequency Energy Research Articles

Efficient rectifier with wide input power range for 5G applications

This article presents three efficient rectifiers for radio frequency energy harvest-ing (RFEH) systems operating at the fifth generation (5G) band (3.5 GHz). Eachrectifier operates at various input power levels (high, low, and across a widepower range). The high and low-power rectifiers feature a single serial topologyusing HSMS-2860 and SMS-7630 Schottky diodes, respectively, along with mi-crostrip lines to implement the input and output filters and the impedance match-ing network. At an radio frequency (RF) power level of 15 dBm, the high-powerrectifier harvests 67.4% to direct current (DC) power with a 300Ωload resistorand an output voltage of 2.5V. The low-power rectifier achieves its maximumpower conversion efficiency (PCE) at -2 dBm, reaching 45% efficiency with a1200Ωload. The rectifier with a extended input power range comprises twobranches of subrectifiers functioning at both high and low power levels. De-pending on the power level, the considered subrectifier harvests radio frequencypower into DC power, while the other subrectifier is deactivated. Across a powerspan of 32.5 dB (ranging from -13 to 19.5 dBm), the rectifier maintains an effi-ciency above 30%. The proposed rectifiers are efficient and suitable for imple-mentation in 5G-enabled RFEH systems.

Review of Sharp Recanalization Techniques in Central Venous Occlusions.

Benign central venous occlusions are frequently associated with long-term central venous access. Most of these occlusions can be recanalized with conventional endovascular technique. When conventional technique fails, sharp recanalization techniques (SRTs) can increase technical success. The SRTs include single low-profile needles, needle coaxial systems, re-entry catheter, the back end of stiff guidewires, and systems that can deliver radiofrequency energy or laser. This review on SRTs presents technical details and outcomes of the most common techniques used in central venous recanalization.

Efficacy and safety of a novel temperature-controlled catheter for cavotricuspid isthmus ablation.

Maintaining an adequate temperature at the target site is essential for effective ablation. We hypothesized that a tissue temperature-controlled (T-Con) catheter for cavotricuspid isthmus (CTI) ablation could improve the procedural ablation parameters. To evaluate the efficacy and safety of the T-Con (DiamondTemp™) catheter for CTI ablation compared with non-irrigation (Non-Irri) and irrigation (Irri) catheters. We analyzed 150 patients who underwent prophylactic CTI ablation combined with pulmonary vein isolation. The Non-Irri, Irri, and T-Con catheter groups comprised 50 patients each, and the ablation procedural parameters and complications were compared between these groups. There were no significant differences in clinical background characteristics among the three groups. The Kruskal-Wallis and post hoc tests demonstrated that the T-Con group showed the lowest total radiofrequency energy delivery time among the three groups (median [25 and 75 percentiles]: 340 [209, 357], 147 [100, 199], and 83 [61, 109] s, respectively in the Non-Irri, Irri, and T-Con groups; T-Con versus Non-Irri, p < .01; T-Con versus Irri, p < .01). The total procedural time and acute reconnection rate in the T-Con group (264 s and 4%, respectively) were lower than those in the Non-Irri group (438 s and 24%) but were similar to those in the Irri group (268 s and 6%). No significant complications were observed in any group. The T-Con catheter achieved a short energy delivery time and a low acute reconnection rate, indicating its potential as an alternative catheter for CTI ablation.

Stabilizing Schottky junction in conjugated polymer diodes enables long-term reliable radio-frequency energy harvesting on plastic

Due to their inherent flexibility, solution-processable conjugated polymers are increasingly being considered for the cost-effective production of thin-film semiconductor devices used in Internet of Everything (IoE) applications. With considerable improvements in charge carrier mobilities, the final challenge impeding the commercialization of conjugated polymers may be improving their environmental and electrical stabilities. Recent studies have improved the stability of computing devices (i.e., transistors) by eliminating interface traps and water molecules within conjugated polymers. However, the stability issue of Schottky diodes, which play a crucial role in configuring thin-film IoE devices used in wireless communication and energy harvesting, has been largely overlooked. This study reveals that aluminum, which is commonly used as a cathode metal in polymer Schottky diodes, creates a nonstoichiometric effect when deposited on conjugated polymers, thereby leading to the formation of charge traps over time, which reduces the rectification ratio of the Schottky diodes and induces a significant bias stress effect during operation. To address this issue, we introduce a zinc-oxide sacrificial interlayer between the conjugated polymer and cathode. This interlayer effectively eliminates the penetrated Al metal or ionized Al-induced nonstoichiometric effect without reducing the charge injection efficiency, achieving exceptional environmental and operational stability. The printed polymer Schottky diodes demonstrate consistent rectifying operation at 13.56 MHz for several months with negligible changes in electrical characteristics.

A metasurface antenna with beam steering capabilities for radio frequency energy harvesting

Limited control over parameters within the realm of design complexity, it is noted that there are incomplete unit cells displaying slightly lower transmittance in transmissive metasurface antennas. However, traditional methods require time-consuming iterative processes to select unit cells with multiple variables. Therefore, a novel approach is proposed for designing metasurface superstrates on patch antennas operating at 12.5 GHz, focusing on achieving beam steering capabilities and Radio Frequency (RF) energy harvesting functionality. It utilizes a Skeleton-based Attentions Neural Network (SANN) to aid in the complex metasurface unit cell design, enhancing the antenna's flexibility and potential applications. This network is trained to generate patterns for the metasurface unit cell, facilitating accurate and efficient design. The key feature of this antenna is beam steering in multiple directions. Steering is achieved by rotating the metasurface plane in an anti-clockwise direction. Experimental results show that by rotating the metasurface plane at different angles, the beam is directed towards specific directions, such as 10°, 15°, 18°, 21°, and 23°. A load resistance of 8kᾨ and a full wave rectifier with a Positive-Intrinsic-Negative (PIN) diode are utilized to obtain a Direct Current (DC) output voltage of 1.1 V in the proposed rectifier. Copper material is used for the metasurface plane, and the antenna is measured using RT duriod.

Catheter ablation for focal atrial tachycardias during pregnancy: A systematic review

ObjectivePregnancy can trigger maternal tachycardias, and the onset of recurrent or incessant focal atrial tachycardia (AT) can lead to tachycardia-induced cardiomyopathy. Medical interventions are commonly employed, but they carry potential fetal and maternal risks. Catheter ablation (CA), particularly with non-fluoroscopic navigation systems, may be considered as an alternative. This systematic review aims to explore the feasibility and outcomes of CA for focal AT during pregnancy. MethodsA thorough literature search was conducted until September 30th, 2023, on PubMed, Embase, and Cochrane databases. Included articles described maternal focal ATs diagnosed through electrophysiological studies and treated with CA. Data derived from these studies were organized into tables and subsequently analyzed. ResultsOut of 278 papers reviewed, 15 articles involving 24 patients were retrieved. CA, utilizing radiofrequency energy achieved acute success in 95.8% of cases. Sixteen patients (66.7%) underwent complete fluoroless procedures, with two adverse events directly related to the procedure reported. Long-term follow-up revealed minimal AT recurrences, with a 0.06% arrhythmia burden in one case. ConclusionFocal ATs during pregnancy can be incessant and refractory to medical intervention, precipitating an acute decline in left ventricular ejection fraction. In this setting, CA emerges as an efficacious treatment modality, particularly in cases of tachycardia-induced cardiomyopathies. Whenever feasible, it is advisable to perform these procedures with minimal or no fluoroscopy guidance. Larger studies are needed to establish the safety and the efficacy of CA for focal ATs during pregnancy, as current research consists of case reports or small case series.

Pulmonary vein isolation using pulsed field ablation vs. high-power short-duration radiofrequency ablation in paroxysmal atrial fibrillation: efficacy, safety, and long-term follow-up (PRIORI study).

Pulsed field ablation (PFA) is a novel, non-thermal, cardiac tissue-selective ablation modality. To date, radiofrequency (RF)-guided high-power short-duration (HPSD) ablation represents the gold standard besides cryo-ablation for pulmonary vein isolation (PVI). This single-centre, retrospective study investigated the efficacy of PFA-PVI vs. HPSD-RF PVI in terms of single-procedure arrhythmia-free outcome and safety in a real-world setting. Consecutive, paroxysmal atrial fibrillation (AF) patients who underwent PVI using PFA or HPSD-RF were enrolled. In group PFA, PVI was performed using a pentaspline PFA catheter. The ablation procedure in group HPSD-RF was performed with RF energy (45 W, ablation index). A total of 410 patients (group PFA, 201; group HPSD-RF, 209) were included. There was no difference between both groups regarding age, gender, and CHA2DS2-VASc score. The procedure time was significantly shorter in group PFA [61 (44-103) vs. 125 (105-143) min; P < 0.001]; fluoroscopy time and dose area product were significantly higher in group PFA [16 (13-20) vs. 4 (2-5) min; P < 0.01 and 412 (270-739) vs. 129 (58-265) μGym2; P < 0.01]. The overall complication rates were 2.9% in group PFA and 6.2% in group HPSD (P = 0.158). There was one fatal stroke in the PFA group. The 1-year Kaplan-Meier estimated freedom from any atrial tachyarrhythmia was 85% with PFA and 79% with HPSD-RF (log-rank P = 0.160). In 56 repeat ablation procedures, the PV reconnection rate was 30% after PFA and 38% after HPSD-RF (P = 0.372). Both PFA and HPSD-RF were highly efficient and effective in achieving PVI in paroxysmal AF patients. The arrhythmia-free survival is comparable. The PV reconnection rate was not different.

Dual-band low-power RF-to-DC signal converter circuits for energy harvesting

This article presents dual-band low-power, high-sensitive radio-frequency (RF)-to-direct current (DC) signal converter circuits, operating at 2.45 and 5.5 GHz bands, for radio frequency energy harvesting applications. In particular, it focuses on the lumped element and microstrip transmission line model circuits. The lumped element RF-to-DC converter circuit is composed of a dual-band impedance matching circuit, voltage-doubler rectifier, and DC-pass filter with a resistive load of 5 kΩ. This converter circuit gives a DC output voltage of 48 mV at 2.45 GHz and 25 mV at 5.5 GHz on −25 dBm input power. Maximum conversion efficiency is 47% at the 2.45 GHz band and 27% at the 5.5 GHz band when the input power is set to −10 dBm. Circuit design steps, matching conditions, performance parameters, and so on, are presented using Advanced Design System simulation. To validate the concept of the lumped element model, a microstrip transmission line RF-to-DC converter model is simulated and fabricated. It also composes of a dual-band matching network, voltage-doubler, and DC-pass filter with a load resistance of 5 kΩ. At a low input power of −18 dBm, it gives an output voltage of 21 mV in measurement. An appropriate match between the simulation and measurement is noted.

Accuracy of Different Surface Electrocardiogram Algorithms for Localization of Accessory Pathway in Comparison to Invasive Electrophysiological Localization: An Observational Study

Introduction: Detection of accessory pathway (AP) on surface ECG in sinus rhythm helps in the diagnosis of Wolff-Parkinson-White Syndrome (WPW Syndrome), Catheter ablation of AP was indicated in symptomatic patients with preexcitation. Pre-ablation AP localization inferred from the 12-lead surface electrocardiogram (ECG) facilitates a tailored ablation strategy; there by specific risk can be properly assessed. As they are based on pre-excitation in the basal state, available algorithms can lead to complex and ambiguous analysis, mostly due to the variable influence of the AP over QRS morphology. Though various algorithms on surface ECG are available to predict the site of AP on surface ECG, but none of them are accurate. So, we have compared the accuracy of different algorithms in predicting the AP localization in comparison to electrophysiological study (EPS) diagnosis. Methodology: This retrospective observational study cohort consisted of 100 consecutive patients above 15 years of age presented to the tertiary care center with the history of palpitations or for assessment of a manifest AP. Accessory pathways were identified according to the site where successful radiofrequency energy was applied. Arruda algorithm, Milstein algorithm, Fitzpatrick algorithm and Pambrun algorithm were applied on a sinus rhythm manifest preexcited ECG to predict the AP localization by two independent investigators who are unaware of site of successful catheter ablation. Then those were compared with the EPS localization to test the accuracy of individual algorithm. Then Cohen’s Kappa was run to determine if there was agreement between any of the four different algorithms with EPS using SPSS version 20.0. Results: In the study population of 100 patients, male to female ratio of study population was 1.6:1, with a mean age of presentation 43.86 ± 11.4 years with the most common age group of 31 to 45 year. when the AP locations were categorized based on EP Study 56 percent of the AP were found on the left side while 43 percent of the AP were found on right side, 77 percent of the AP were septal pathways. Among the leftsided pathways, left anteroseptal constitutes majority followed by left posteroseptal pathway. On right side majority were in right posteroseptal location in our study. Based on 4 surface ECG algorithms AP was localized and each algorithm was compared with invasive EPS localization for accuracy using Cohen’s Kappa agreement analysis. As per agreement analysis the kappa value for Milstein, Pambrun algorithm, Fitzpatrik and Arruda were 0.188, 0.343, 0.441, and 0.645 respectively. It was found that Arruda algorithm had moderate strength of agreement with the findings of EPS (κ = 0.645). This is the proportion of agreement over and above chance agreement and which was statistically significant and the strongest among all the four algorithms. Conclusion: Our study has compared the accuracy of 4 surface ECG algorithms in predicting the accessory pathway localization with the EPS; it has demonstrated that the Arruda algorithm is more precise and accurate among the available algorithms followed by Fitzpatrik, Pambrun algorithm and Milstein algorithm, Knowing the pathway prior to ablation allows for optimal procedure preparation, mapping pathways that are difficult to find and finally may lessen the catheter-related injury and shortens the procedural time.

Advances in radiofrequency ablation: mechanism of action and technology.

Radiofrequency ablation (RFA) is a minimally invasive treatment modality that utilizes high-frequency alternating current to destroy targeted tissues through thermal ablation. This manuscript provides an overview of the advancements in RFA, focusing on its mechanism of action and technological innovations. RFA technology was first introduced in the early 1900's, and its use has expanded and evolved, especially in its current utility in the treatment of painful conditions. As the technology has evolved, new techniques, applications and modalities have expanded its use and improved its efficacy. RFA works by applying radiofrequency energy through specialized electrodes, leading to resistive heating and coagulation necrosis. Its advantages include precise tissue targeting, minimal invasiveness, reduced complications, and faster recovery compared to traditional surgical interventions. Technological advancements in RFA have led to improved treatment outcomes. Multi-electrode systems allow for larger ablation zones. Image-guided RFA improves treatment planning and minimizes damage to healthy tissues. Cooled-tip and perfusion electrodes address limitations such as heat sink effects, enhancing RFA's efficacy in challenging anatomical regions. These developments have expanded RFA's applications to liver tumors, lung tumors, renal tumors, cardiac arrhythmias, and chronic pain syndromes. In conclusion, RFA has emerged as a safe and effective thermal ablation technique. Understanding its mechanism of action and integrating advanced technologies have significantly enhanced treatment outcomes. Continued research and innovation in RFA hold immense potential for further improving patient care and outcomes.

Kinerja Sistem Hybrid Radio Frequency Energy Harvesting Pada Sistem Komunikasi V2V

This article investigates the impact of hybrid Radio Frequency Energy Harvesting (RF-EH) techniques on cooperative Vehicle-to-Vehicle (V2V) communications systems. The energy harvesting (EH) process is carried out in the vehicle or vehicle transmitter as a source using the Time Switching (TS) protocol and in the vehicle or relay vehicle using the Power Splitting (PS) protocol. The transmitter or source vehicle obtains the RF signal for the EH process from the base station (BS), while the relay vehicle obtains the RF signal from the transmitter or source vehicle. System performance is presented with Outage Probability (OP) values ​​for different EH parameters, namely, time switching factor, α and power splitting factor â. From the simulation results, all parameters influence the OP value. The higher the value of the RF-EH parameters (α and â) results in a lower OP value. For noise power, N_0 = -100 dBm, the best OP value for α = 0.7 is 0.1214 and the best OP value for â = 0.8 is 0.1557.

Research progress and clinical application of cooled radiofrequency ablation

Radiofrequency ablation (RFA) is a minimally invasive clinical treatment that uses radiofrequency energy to generate heat, resulting in the thermal necrosis of targeted tissues. To enhance the therapeutic benefits of traditional RFA, cooled RFA (CRFA) technology has been developed. CRFA incorporates cooling technology to prevent thermal damage and rapid impedance changes caused by tissue overheating. This review article provides a comprehensive overview of various types of cooling electrode needles used in CRFA, as well as an evaluation of their efficacy and clinical applications. We discuss the advantages of CRFA, including its minimally invasive nature, improved safety profile, and highly effective treatment outcomes. Nevertheless, certain problems and limitations are also addressed to optimize the potential of CRFA as a clinical treatment option. Overall, CRFA has promising prospects. With continued advancements in technology and further research, this innovative treatment modality is expected to significantly impact the treatment of a wide range of medical conditions.

Lesion durability found during mandated percutaneous catheter ablation after surgical cryo-ablation for treatment of non-paroxysmal atrial fibrillation

ObjectivesCurrent recommendations support surgical treatment of atrial fibrillation (AF) in patients indicated for cardiac surgery. These procedures are referred to as concomitant and may be carried out using radiofrequency energy or cryo-ablation. This study aimed to assess the electrophysiological findings in patients undergoing concomitant cryo-ablation.MethodsPatients with non-paroxysmal AF undergoing coronary artery bypass grafting and/or valve repair/replacement were included in the trial if concomitant cryo-ablation was part of the treatment plan according to current guidelines. The patients reported in this study were assigned to undergo staged percutaneous radiofrequency catheter ablation (PRFCA), i.e., hybrid treatment, as a part of the SURHYB trial protocol.ResultsWe analyzed 103 patients who underwent PRFCA 105 ± 35 days after surgery. Left and right pulmonary veins (PVs) were found isolated in 65 (63.1%) and 63 (61.2%) patients, respectively. The LA posterior wall isolation and mitral isthmus conduction block were found in 38 (36.9%) and 18 (20.0%) patients, respectively. Electrical reconnections (gaps) in the left PVs were more often localized superiorly than inferiorly (57.9% vs. 26.3%, P = 0.005) and anteriorly than posteriorly (65.8% vs. 31.6%, P = 0.003). Gaps in the right PVs were more equally distributed anteroposteriorly but dominated in superior segments (72.5% vs. 40.0%, P = 0.003). There was a higher number of gaps on the roof line compared to the inferior line (131 (67.2%) vs. 67 (42.2%), P < 0.001). Compared to epicardial cryo-ablation, endocardial was more effective in creating PVs and LA posterior wall isolation (P < 0.05). Cryo-ablation using nitrous oxide (N20) or argon (Ar) gas as cooling agents was similarly effective (P = NS).ConclusionsThe effectiveness of surgical cryo-ablation in achieving transmural and durable lesions in the left atrium is surprisingly low. Gaps are located predominantly in the superior and anterior portions of the PVs and on the roof line. Endocardial cryo-ablation is more effective than epicardial ablation, irrespective of the cooling agent used.

Evaluation of Recycled Cardboard Paper as an Eco-Friendly Substrate for Rectenna and Ambient Radio Frequency Energy Harvesting Application

Developers of electronics for the Internet of Things are considering nonstandard substrate materials like recyclable, low-cost, and eco-friendly cardboard paper. From this perspective, this article reviews the design and experimental results of a 2D-rectenna for scavenging radio-frequency energy at 2.45 GHz on various cardboard paper substrates for both the antenna and rectifier. Four types of recycled cardboard material, each with different thicknesses, air gaps, and surface roughness, are selected for characterization. A linearly polarized rectangular microstrip patch antenna with microstrip transmission feeding is adopted for ease of fabrication. At 2.45 GHz, the antenna has a simulated and measured global gain of 2.98 dB and 2.53 dB, respectively, on a 2.2 mm thick cardboard material. The rectifying element consists of a voltage-doubler configuration connected through a T-matching network to the antenna. At low RF input power (−10 dBm), the maximum available DC output power is experimentally evaluated at 1.73 μW, 7.5 μW, and 8.5 μW for HSMS-2860, HSMS-2850, and SMS7306-079L diodes, respectively. The respective rectifiers with diodes SMS7306-079L, HSMS-2850, and HSMS-2860 exhibit optimal load values of 2 kΩ, 2.6 kΩ, and 8 kΩ. The rectifier designed using the SMS7306-079L diode experimentally reaches a maximum power conversion efficiency (PCE) of 14.2% at −5 dBm input power when the optimal load value is 1.5 kΩ.

Ambient nano RF-Energy driven self-powered wearable multimodal real-time health monitoring

As the trend of population aging intensifies, the demand for continuous and efficient health monitoring for solitary elderly individuals and those with limited self-care capabilities is growing. Traditional wearable health monitoring devices primarily rely on battery power, which not only incurs high maintenance costs but also risks interruption of monitoring due to battery depletion. To address these issues, this paper introduces a self-powered flexible wearable monitoring device utilizing far-field Radio Frequency Energy Harvesting (RFEH) technology. This device powers integrated sensors and Bluetooth by harvesting RF energy from ambient Wi-Fi and other wireless signals, enabling real-time monitoring of the wearer's physical behaviour and health status with immediate feedback via mobile terminals. Under conditions of 100 cm distance and a power intensity of 0.8 dBm, the system can charge a 220 μF capacitor to 4.12 V within just 23.24 seconds, ensuring stable operation of the device. Moreover, the monitoring device is equipped with a low-power wireless sensor system capable of sampling up to 100 Hz, which accurately and promptly tracks and analyzes key health indicators such as walking, physiological activities, and respiratory status. This technology provides a reliable health monitoring solution for elderly individuals living alone and those with difficulties in self-care, significantly enhancing the effectiveness of remote medical services, improving their quality of life, and reducing the occurrence of emergency medical events. This research not only advances wearable device technology but also paves new paths for health management in an aging society.

Drone Shaped Fractal Antenna with Defected Ground Structure for RF Energy Harvesting Applications

A proposed multiband drone shaped fractal antenna (Antenna-1) is introduced in this paper that targets the most required frequencies used for radio frequency energy harvesting applications, including WLAN-2.4G, WLAN-5G, WLAN-6G, Mobile DCS1700, Mobile LTE and WIMAX services. A novel fractal shape is designed and combined with a standard square geometrical shape in order to implement the front patch of the antenna. The antenna is simulated with CST Studio Suite software and fabricated on FR-4 substrate. Different antenna stages with parametric study and optimization were implemented to get the best performance from the drone shape fractal antenna. The multiband (Antenna-1) supports six resonate frequencies (1.7155 GHz, 2.424 GHz, 3.36 GHz, 3.789 GHz, 5.843 GHz, 6.886 GHz) with peak gain of (2.83 dBi) at the frequency 2.45 GHz and a maximum bandwidth of (0.4281 GHz) at the frequency 5.8 GHz that make it a suitable antenna for radio frequency energy harvesting applications.

Coblation Versus Surgical Debridement Against MRSA Infection in Wounds With Shrapnel: A Preliminary Study.

Debridement plays a critical role in wound management. In addition to removing necrotic tissue, debridement can eliminate bacteria frequently harbored within the tissue. This study evaluated a novel debridement method that uses plasma-based radiofrequency technology to remove tissue and bacteria. Coblation is a technology that uses radiofrequency energy to excite the electrolytes in a conductive medium, such as saline, to create a precisely focused plasma. This plasma field contains highly energized particles that possess sufficient energy to break tissue molecular bonds, causing the tissue to dissolve at relatively low temperatures (typically 40 °C to 70 °C). Eighteen deep dermal wounds measuring 22 mm × 22 mm × 3 mm deep were created on pigs. Wounds were inoculated with methicillin-resistant Staphylococcus aureus USA300 (MRSA USA300) in combination with shrapnel and then covered with a polyurethane dressing for 24 hours. Wounds were then randomly assigned to one of the 3 treatment groups: (1) Coblation, (2) surgical debridement, and (3) no debridement. Wounds were biopsied on days 0, 5, 9, and 12, and specimens were processed for MRSA counts using selective media. Statistical analysis was performed using IBM SPSS statistics 27 using one-way ANOVA. Comparison between coblation and surgical debridement showed a decrease in bacterial count in all assessment times. The lowest bacterial count in all assessment times was observed in wounds debrided with coblation showing a statistically significant (P ≤ .05) decrease in more than 2 Log CFU/g on days 0, 5, and 9 compared to no debridement. On day 12, coblation-debrided wounds exhibited 6.10 ± 0.22 Log CFU/g, and this value represents 99.99% of reduction compared with non-debrided wounds (P ≤ .05). More than 96% of reduction (P ≤ .05) resulted in wounds treated with coblation compared with surgically debrided. Reducing MRSA bacterial infection counts, especially of biofilm-associated organisms, in combination with shrapnel may have important clinical implications, especially for the military personnel. Further research into the use of this technology in wound management is warranted.

Comparison between cryotherapy and radiofrequency energy sources for parahisian accessory pathway percutaneous ablation.

Catheter ablation of parahisian accessory pathways (PHAP) are challenging due to their proximity to the normal conduction system. Retrospective studies suggest that cryoablation has a better safety profile but a higher recurrence rate when compared to radiofrequency ablation (RFCA). The objective of this study was to compare the results of parahisian AP ablation performed by electrophysiologists with experience in both technologies. Prospective single-center, non-blinded and 1:1 model was used. Patients included had parahisian AP confirmed by an electrophysiological study and referred for radiofrequency or cryotherapy ablation according to current guidelines, under fluoroscopic guidance. No electroanatomic mapping was used. A total of 30 patients (mean age of 25±9.4 years; 90% male) were enrolled between Oct/2018 to Feb/2020. Acute success rate between RFCA and CRYO were similar (93% vs. 87%, p = 0.54). A nonsignificant reduction in short-term recurrence rate for RFCA (14% vs. 30%, p = 0.3) and mechanical trauma (6% vs. 20%; p = 0.28) was observed. Long-term recurrence rate and event-free survival time were similar in both groups after 1-year follow-up (p = 0.286). No persistent complete AV block or conduction disturbance was also observed. Considering the limitation of a small sample size and the lack of use of electroanatomic mapping for RFCA, the efficacy and safety profile of parahisian AP ablation with RFCA was not different from CRYO, when performed by experienced electrophysiologists. No cases of permanent complete AV block were reported with either energy modalities.

State-of-the-art pulsed field ablation for cardiac arrhythmias: ongoing evolution and future perspective.

Pulsed field ablation (PFA) is an innovative approach in the field of cardiac electrophysiology aimed at treating cardiac arrhythmias. Unlike traditional catheter ablation energies, which use radiofrequency or cryothermal energy to create lesions in the heart, PFA utilizes pulsed electric fields to induce irreversible electroporation, leading to targeted tissue destruction. This state-of-the-art review summarizes biophysical principles and clinical applications of PFA, highlighting its potential advantages over conventional ablation methods. Clinical data of contemporary PFA devices are discussed, which combine predictable procedural outcomes and a reduced risk of thermal collateral damage. Overall, these technological developments have propelled the rapid evolution of contemporary PFA catheters, with future advancements potentially impacting patient care.

Is Renal Denervation Effective in Treating Resistant Hypertension?

Resistant hypertension is diagnosed in patients whose blood pressure target is unmet despite the use of three or more antihypertensive medications. Systemic sympathetic hyperactivation is associated with the development of resistant hypertension. As the kidney is largely pervasive of the sympathetic nervous system renal denervation procedure was developed to control blood pressure by attenuating the renal and systemic sympathetic hyperactivity. Renal denervation is a minimally invasive procedure that uses radiofrequency or ultrasound energy waves to reduce the activity of the renal artery nerves. Previous clinical trials have shown conflicting results regarding the efficacy of the procedure. Symplicity HTN-1 and -2 trials showed effective blood pressure lowering results in the renal denervation group with a good safety profile. However, the Symplicity HTN-3 trial showed no difference in blood pressure lowering effect between the renal denervation and control Sham procedure groups. Notwithstanding, some recent clinical trials with Sham control and meta-analysis showed clinical benefits of renal denervation. Other clinical benefits of renal denervation include glucose control, cardiovascular protective effect, reduction of obstructive sleep apnea, and neuralgia control. A subset of patients with satisfactory blood pressure control response to the procedure may experience improved glucose control due to the overall reduced sympathetic activity and insulin resistance. Sympathetic activity control after renal denervation has cardioprotective effects, especially for those with arrhythmia and left ventricular hypertrophy. Also, renal denervation could be helpful in renalorigin pain control. Renal denervation is an effective, safe, non-invasive procedure with many clinical benefits beyond blood pressure control. Further development in the procedure technique and selection of target patients are needed for wider clinical use of renal denervation in resistant hypertension.