New Technologies in Atrial Fibrillation Ablation

Genomic insights into heart health: Exploring the genetic basis of cardiovascular disease

Cardiovascular diseases (CVDs) are considered as the leading cause of death worldwide. CVD continues to be a major cause of death and morbidity despite significant improvements in its detection and treatment. Therefore, it is strategically important to be able to precisely characterize an individual's sensitivity to certain illnesses. The discovery of genes linked to cardiovascular illnesses has benefited from linkage analysis and genome-wide association research. The last 20 years have seen significant advancements in the field of molecular genetics, particularly with the development of new tools like genome-wide association studies. In this article we explore the profound impact of genetic variations on disease development, prognosis, and therapeutic responses. And the significance of genetics in cardiovascular risk assessment and the ever-evolving realm of genetic testing, offering insights into the potential for personalized medicine in this domain. Embracing the future of cardiovascular care, the article explores the implications of pharmacogenomics for tailored treatments, the promise of emerging technologies in cardiovascular genetics and therapies, including the transformative influence of nanotechnology. Furthermore, it delves into the exciting frontiers of gene editing, such as CRISPR/Cas9, as a novel approach to combat cardiovascular diseases. And also explore the potential of stem cell therapy and regenerative medicine, providing a holistic view of the dynamic landscape of cardiovascular genomics and its transformative potential for the field of cardiovascular medicine.

The shape of the left lateral ridge as a predictor of long-term outcome of catheter ablation for atrial fibrillation based on clinical and experimental data

BACKGROUND

The left lateral ridge (LLR) is an important structure for ablation of atrial fibrillation (AF). This study assessed how the LLR shape is associated with the long-term outcomes of AF ablation and investigated the relationship with radiofrequency (RF) lesion formation.

METHODS AND RESULTS

Clinical study - we assessed multi-detector computed tomography (MDCT) images in 247 patients who underwent AF ablation. Patients were classified into two groups according to the shape of the LLR: Narrow LLR group (n = 116; 47%) and Wide LLR group (n = 131; 53%). After a follow-up period 475 ± 245 days, the AF-free rate was significantly higher in the wide LLR than Narrow LLR group (83.2% vs. 62.9%, p = 0.0004). A multivariate analysis showed that the shape of the LLR was an independent predictor of AF recurrence after ablation (hazard ratio 2.58; 95% confidential interval = 1.48-4.51, p = 0.001). Experimental study - Two types of the ridge models were made with porcine atrial tissues: "Narrow ridge(4.2 ± 0.9 mm)" and "Wide ridge(9.7 ± 1.8 mm)" RF ablation was performed on each ridge model using a contact force (CF)-sensing catheter. The mean CF and the RF lesion volume of the narrow ridge were significantly less than those of the wide ridge model (5.42 ± 3.13 g vs. 10.37 ± 3.98 g, p = 0.001; 19.8 ± 9.9 mm³ vs. 44.2 ± 13.6 mm³, p < 0.001, respectively).

CONCLUSIONS

AF recurrence after ablation was more frequent in patients with a narrow LLR. LLR shape as assessed using MDCT is associated with long-term outcomes after AF ablation. CF and lesion formation data using the porcine atrial tissue model support our clinical results.

Nanotechnology, an alternative with promising prospects and advantages for the treatment of cardiovascular diseases

Cardiovascular diseases (CVDs) are one of the most important causes of mortality and affecting the health status of patients. At the same time, CVDs cause a huge health and economic burden to the whole world. Although a variety of therapeutic drugs and measures have been produced to delay the progress of the disease and improve the quality of life of patients, most of the traditional therapeutic strategies can only cure the symptoms and cannot repair or regenerate the damaged ischemic myocardium. In addition, they may bring some unpleasant side effects. Therefore, it is vital to find and explore new technologies and drugs to solve the shortcomings of conventional treatments. Nanotechnology is a new way of using and manipulating the matter at the molecular scale, whose functional organization is measured in nanometers. Because nanoscale phenomena play an important role in cell signal transduction, enzyme action and cell cycle, nanotechnology is closely related to medical research. The application of nanotechnology in the field of medicine provides an alternative and novel direction for the treatment of CVDs, and shows excellent performance in the field of targeted drug therapy and the development of biomaterials. This review will briefly introduce the latest applications of nanotechnology in the diagnosis and treatment of common CVDs.

Iterative Jacobian-Based Inverse Kinematics and Open-Loop Control of an MRI-Guided Magnetically Actuated Steerable Catheter System

This paper presents an iterative Jacobian-based inverse kinematics method for an MRI-guided magnetically-actuated steerable intravascular catheter system. The catheter is directly actuated by magnetic torques generated on a set of current-carrying micro-coils embedded on the catheter tip, by the magnetic field of the magnetic resonance imaging (MRI) scanner. The Jacobian matrix relating changes of the currents through the coils to changes of the tip position is derived using a three dimensional kinematic model of the catheter deflection. The inverse kinematics is numerically computed by iteratively applying the inverse of the Jacobian matrix. The damped least square method is implemented to avoid numerical instability issues that exist during the computation of the inverse of the Jacobian matrix. The performance of the proposed inverse kinematics approach is validated using a prototype of the robotic catheter by comparing the actual trajectories of the catheter tip obtained via open-loop control with the desired trajectories. The results of reproducibility and accuracy evaluations demonstrate that the proposed Jacobian-based inverse kinematics method can be used to actuate the catheter in open-loop to successfully perform complex ablation trajectories required in atrial fibrillation ablation procedures. This study paves the way for effective and accurate closed-loop control of the robotic catheter with real-time feedback from MRI guidance in subsequent research.

Reduction of Fluoroscopy Time and Radiation Dosage During Catheter Ablation for Atrial Fibrillation

Radiofrequency catheter ablation has become the treatment of choice for atrial fibrillation (AF) that does not respond to antiarrhythmic drug therapy. During the procedure, fluoroscopy imaging is still considered essential to visualise catheters in real-time. However, radiation is often ignored by physicians since it is invisible and the long-term risks are underestimated. In this respect, it must be emphasised that radiation exposure has various potentially harmful effects, such as acute skin injury, malignancies and genetic disease, both to patients and physicians. For this reason, every electrophysiologist should be aware of the problem and should learn how to decrease radiation exposure by both changing the setting of the system and using complementary imaging technologies. In this review, we aim to discuss the basics of X-ray exposure and suggest practical instructions for how to reduce radiation dosage during AF ablation procedures.

Atrial fibrillation ablation in the era of cryoballoon and force-sensing catheters: freeze or burn?

OPINION STATEMENT

Atrial fibrillation can adversely affect the quality of life for many patients. Though antiarrhythmic drug therapy remains an option for the treatment of atrial fibrillation, the drugs are associated with numerous side effects. Atrial fibrillation ablation has been shown to be as efficacious as antiarrhythmic drug therapy. The field of atrial fibrillation ablations has evolved over time from utilizing radiofrequency energy to using cryoenergy. Newer technologies are being developed with efforts to improve outcomes in patients undergoing atrial fibrillation ablations. This article will highlight two such technologies: cryoballoon ablation catheters and contact force-sensing catheters. These novel catheters appear to be further revolutionizing this young field in electrophysiology.

New Ablation Technologies and Techniques

Catheter ablation is an established treatment strategy for a range of different cardiac arrhythmias. Over the past decade two major areas of expansion have been ablation of atrial fibrillation (AF) and ventricular tachycardia (VT) in the context of structurally abnormal hearts. In parallel with the expanding role of catheter ablation for AF and VT, multiple novel technologies have been developed which aim to increase safety and procedural success. Areas of development include novel catheter designs, novel navigation technologies and higher resolution imaging techniques. The aim of the present review is to provide an overview of novel developments in AF ablation and VT ablation in patients with of structural cardiac diseases.

Atrial fibrillation

Atrial fibrillation is the most common arrhythmia affecting patients today. Disease prevalence is increasing at an alarming rate worldwide, and is associated with often catastrophic and costly consequences, including heart failure, syncope, dementia, and stroke. Therapies including anticoagulants, anti-arrhythmic medications, devices, and non-pharmacologic procedures in the last 30 years have improved patients' functionality with the disease. Nonetheless, it remains imperative that further research into AF epidemiology, genetics, detection, and treatments continues to push forward rapidly as the worldwide population ages dramatically over the next 20 years.

Visual, tactile, and contact force feedback: which one is more important for catheter ablation? Results from an in vitro experimental study

BACKGROUND

During radiofrequency ablation, effective contact is crucial in determining lesions efficacy.

OBJECTIVE

The purpose of this study was to compare operators' ability to assess contact pressure using visual and tactile feedbacks together or alone in an experimental model.

METHODS

In a in vitro experimental setup replicating manual catheter manipulation and recording the applied force, evaluators were asked to identify three levels of force (first, ablation, and maximum contact) as the catheter contacted the tissue model using (1) visual feedback only by fluoroscopy, "blinded" to touch; (2) tactile feedback only, blinded to fluoroscopy; and (3) both tactile and visual feedback together. The latter was regarded as reference. The experiment was repeated using a catheter force sensing technology during robotic navigation.

RESULTS

During manual navigation, tighter association was shown for the visual method than for the tactile method: median difference with reference: first contact -1 (P = .97) vs -2 (P = .90); ablation contact 2 (P = .1) vs -7 (P = .03); maximum contact 2 (P = .06) vs -28 (P = .02). Bland-Altman plot and Deming regression confirmed for the visual method the good agreement with reference and the absence of bias at any level and showed for the tactile higher values and proportional bias that reached statistical significance at ablation and maximum contact. During robotic navigation, agreement was higher for the tactile than for the visual only method.

CONCLUSION

During manual navigation, visual feedback alone is in better agreement with the reference compared to the tactile only approach. During robotic navigation, agreement is looser for the visual only approach. More objective feedback of contact pressure during ablation procedures is desirable.

The burden of atrial fibrillation in the Netherlands

BACKGROUND

Atrial fibrillation (AF) is the most common sustained atrial arrhythmia and it is independently associated with an increased morbidity and mortality. As a result of the high prevalence of AF, the economic and clinical impact of the disease is substantial. This study describes the economic and clinical impact of AF in the Netherlands.

METHODS

Epidemiological data on AF in the Netherlands were projected on population estimates of the Netherlands in 2009 and combined with data on the cost of AF and its interventions.

RESULTS

Overall prevalence of AF in the Netherlands is 5.5% in the population over 55 years, corresponding to about 250,000 AF patients. The prevalence increases with age, and the mean age of AF patients is 69.3 years. Incidence of AF in the Netherlands varies with age, from 1188 new cases in the age group of 55 to 59 up to 7074 new cases in the age group 75 to 79. Total new cases amounts to 45,085 patients per year in the Netherlands. Total costs of AF in the Netherlands are <euro> 583 million, of which the majority (70%) were accounted for by hospitalisations and in-hospital procedures. Pharmacotherapeutic management of AF totalled <euro> 17 million in the Netherlands in 2009.

DISCUSSION

AF is a serious disease with a high clinical and economic burden, especially due to hospitalisations as a result of cardiovascular events. The number of patients with AF in the Netherlands is considerable and will increase with the ageing population in the future.

Remote magnetic navigation in atrial fibrillation

Atrial fibrillation (AF) is of profound public health importance and is largely a disease of aging and is responsible for increased morbidity- and mortality-related healthcare expenditures. Catheter ablation to isolate the pulmonary veins has become the therapy of choice for treatment of drug-refractory AF. Procedures can be very challenging and multiple difficulties must be overcome in order to achieve a successful outcome. The magnetic navigation system (MNS) has advantages in catheter maneuverability, stability and reproducibility. Due to the catheter design safety and efficacy of AF, ablation has increased. New developments are being made to allow fully remote ablation procedures in combination with the MNS. However, new technologies are still necessary to improve MNS ablation for AF.

Radiofrequency ablation for treatment of atrial fibrillation

INTRODUCTION

Atrial Fibrillation (AF) is the most common cardiac arrhythmia which represents a major public health problem. The main purpose of this research is to evaluate the Radiofrequency (RF) ablation effects in the patients with chronic AF scheduled for cardiac surgery because of different heart diseases.

METHODS

The descriptive and prospective study was conducted on 60 patients with AF scheduled for surgery along with RF ablation. The data were collected by questionnaire and included: patients' age, sex, NYHA class, operation type, past medical history, type and cause of valvular heart disease, preoperative ECG (electrocardiogram), duration of surgery, clamping time, cardiopulmonary bypass, and RF ablation time. RF ablation was followed by the main operation. The follow up examination, ECG, and echocardiography were performed 3 and 6 months after operation.

RESULTS

The mean age of patients was 48±10 years (18-71 years). Forty one patients had permanent AF and 19 had the persistent AF. The left ventricular ejection fraction was 48.27±9.75 percent before operation, and reached to 56.27±7.87 percent after the surgery (P<0.001). The mean NYHA class before the surgery was 2.83±0.68 which decreased to 1.34±0.46 6 months after the surgery with RF ablation (P<0.001). One patient (1.6%) died after surgery. Complete relief and freedom from AF recurrence was observed in 70% of patients in the mean follow up in 7 months after the surgery. The sinus rhythm with efficient atrial contraction was established in 100% of discharged patients.

CONCLUSION

RF ablation is an effective procedure to cure atrial fibrillation in patients undergoing cardiac surgeries.

A novel radiofrequency ablation catheter using contact force sensing: Toccata study

OBJECTIVES

The aim of this multicenter study was to evaluate the device- and procedure-related safety of a novel force-sensing radiofrequency (RF) ablation catheter capable of measuring the real-time contact force (CF) and to present CF data and its possible implications on patient safety.

BACKGROUND

The clinical outcome of RF ablation for the treatment of cardiac arrhythmias may be affected by the CF between the catheter tip and the tissue. Insufficient CF may result in an ineffective lesion, whereas excessive CF may result in complications.

METHODS

Seventy-seven patients (43 with right-sided supraventricular tachycardia [SVT] and 34 with atrial fibrillation [AF]) received percutaneous ablation with the novel studied catheter. The CF applied and safety events related to the procedure were reported.

RESULTS

CF values at mapping ranged from 8 ± 8 to 60 ± 35 g and from 12 ± 10 to 39 ± 29 g in the SVT group and the LA group, respectively, showing a significant interinvestigator variability (P < .0001). High transient CFs (>100 g) were noted in 27 patients (79%) of the LA group. One device-related complication (tamponade, 3%) occurred in the AF group.

CONCLUSIONS

Catheter ablation using real-time CF technology is safe for the treatment of SVT and AF. High CFs may occur during catheter manipulation and not just during ablation, suggesting that measuring CF may provide additional useful information to the operator for safe catheter manipulation. In the future, CF-sensing catheters may also increase the effectiveness of RF ablations by allowing better control of the RF lesion size.