Performance of an Irrigated Bipolar Radiofrequency Ablation Clamp on Explanted Human Hearts

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society (HRS), the Asia Pacific HRS, and the Latin American HRS.

Efficacy of a surgical cardiac ablation clamp using nanosecond pulsed electric fields: An acute porcine model

OBJECTIVE

To examine the effectiveness of a recently developed nonthermal technology, nanosecond pulse-field ablation (nsPFA), for surgical ablation of the atria in a beating heart porcine model.

METHODS

Six pigs underwent sternotomy and ablation using an nsPFA parallel clamp. The ablation electrodes (53 mm long) were embedded in the jaws of the clamp. Nine lesions per pig were created in locations chosen to be representative of the Cox-maze procedure. Four lesions were intended to electrically isolate parts of the atrium: the right atrial appendage, left atrial appendage, right pulmonary veins, and left pulmonary veins. For these lesions, exit block testing was performed both after ablation and before euthanasia; the time between the 2 tests was 3.3 ± 0.5 hours (range, 2-4 hours). Using purse string sutures, 5 more lesions were created up to the superior vena cava, down to the inferior vena cava, across the right atrial free wall, and at 2 distinct locations on the left atrial free wall. The clamp delivered a train of nanosecond duration pulses, with a total duration of 2.5 seconds, independent of tissue thickness. The heart tissue was stained with 1% triphenyltetrazolium chloride after a dwelling period of 2 hours. Subsequently, each lesion was cross sectioned at 5-mm intervals to assess the ablation depth and transmurality. In some sections, transmurality could not be established on the basis of triphenyltetrazolium chloride staining alone; for these lesions, Gomori-trichrome stains were used, and the histologic sections were evaluated for transmurality.

RESULTS

The ablation time was 2.5 seconds per lesion, for a total of only 22.5 seconds ablation time to create 9 lesions. A total of 53 lesions were created, resulting in 388 separate histologic sections. Transmurality was established in 386 sections (99.5%). Mean tissue thickness was 3.1 ± 1.5 mm (range, 0.2-8.6 mm). Exit block was confirmed in 23 of the 24 lesions (96%) postablation and 23 of 24 (96%) before the animals were humanely killed. Over the course of the procedure, neither pulse-induced arrhythmias nor any other complications were noted.

CONCLUSIONS

The novel nsPFA clamp device was effective in creating acute conduction block and transmural lesions in both the right and left atria in an acute porcine model. This nonthermal energy source has great potential to both shorten procedural time and enable effective ablation in the beating heart.

2024 European Heart Rhythm Association/Heart Rhythm Society/Asia Pacific Heart Rhythm Society/Latin American Heart Rhythm Society expert consensus statement on catheter and surgical ablation of atrial fibrillation

In the last three decades, ablation of atrial fibrillation (AF) has become an evidence-based safe and efficacious treatment for managing the most common cardiac arrhythmia. In 2007, the first joint expert consensus document was issued, guiding healthcare professionals involved in catheter or surgical AF ablation. Mounting research evidence and technological advances have resulted in a rapidly changing landscape in the field of catheter and surgical AF ablation, thus stressing the need for regularly updated versions of this partnership which were issued in 2012 and 2017. Seven years after the last consensus, an updated document was considered necessary to define a contemporary framework for selection and management of patients considered for or undergoing catheter or surgical AF ablation. This consensus is a joint effort from collaborating cardiac electrophysiology societies, namely the European Heart Rhythm Association, the Heart Rhythm Society, the Asia Pacific Heart Rhythm Society, and the Latin American Heart Rhythm Society .

Performance of a non-irrigated bipolar radiofrequency ablation clamp on beating human hearts

OBJECTIVE

This study is intended to examine the efficacy of a non-irrigated bipolar RF clamp and explore the factors that can influence its performance on beating human hearts using the electrophysiology mapping method.

METHODS

A total of 83 atrial fibrillation (AF) patients were included in this study. Based on the Body mass index (BMI, kg/m2), the AF patients were divided into the normal group (18.5 ≤ BMI < 25) and the overweight or obese group (BMI ≥ 25). They all underwent a stand-alone surgical ablation through our off-pump biatrial mini-maze procedure. After we completed each time of ablation, the achievement of PV isolation was checked using the electrophysiology mapping method. The number of ablation times to achieve the PV isolation on the left and right PVs was recorded respectively.

RESULTS

86.7% (72/83) PV isolation on the LPV and 72.3% (60/83) PV isolation on the RPV could be achieved respectively after performing a single time of surgical ablation. Three times of ablations resulted in 100.0% PV isolation on the left and right PVs. In the normal BMI group, the ratio of patients who achieved a complete PV isolation after a single time of ablation was 83.7% (36/43), which was higher than the 60.0% (24/40) in the overweight or obese group.

CONCLUSIONS

Performing three times of ablations resulted in 100% PV isolation on the left and right PVs. The bipolar RF clamp had a better performance on the LPV than on the RPV. The patients' BMI also influenced the Atricure clamp' s performance.