Pierre Cheng Qian

Background: Very high‐power short‐duration (vHPSD) radiofrequency ablation (RFA) is an alternative strategy for pulmonary vein isolation. However, rapid temperature rises may cause complications. The QDOT Micro is designed to detect temperature rises for automatic power and irrigation flow adjustments. We compared how differences in ablation electrode design between three RFA catheters impact vHPSD lesions. Methods: vHPSD RFA was performed within a validated gel tank model. Four‐second ablations were delivered with stable contact force using the QDOT, SmartTouch, and TactiFlex SE at 60, 70, 80, and 90 watts, positioned perpendicular (90°), oblique (45°), and parallel (0°) to the ablation target, utilizing 0.9% and 0.45% “half‐normal” saline (HNS) irrigation. The SmartTouch and TactiFlex were operated in power‐controlled mode, and each configuration was repeated three times, with images captured every second to characterize lesions. Results: In total, 216 vHPSD lesions were delivered. At 90 W, 90°, and 0.9% saline, the QDOT produced lesions with a mean depth of 1.93 mm. The TactiFlex produced shallower lesions, with a mean depth of 1.88 mm ( p = 0.02), and the SmartTouch produced the deepest, with a mean depth of 2.37 mm ( p < 0.001). The mean diameter of QDOT lesions, at 4.63 mm, was comparable to TactiFlex lesions (4.58 mm, p  = 0.8), whilst the SmartTouch lesions were significantly wider than both the QDOT and TactiFlex (6.04 mm, p < 0.001). Steam‐pop risk, based on lesion temperature, was lowest for the TactiFlex. Conclusion: vHPSD lesions produced with the QDOT achieved greater dimensions and temperatures than those with the TactiFlex under controlled conditions, suggesting a difference in the cooling profile of the ablation electrodes. vHPSD with the SmartTouch or 0.45% HNS are likely to increase the risk of steam pops.

Background: Very high short duration radiofrequency catheter ablation can rapidly achieve pulmonary vein isolation, however safety to the esophagus during posterior left atrial ablation is uncertain. This study looked to characterise lesion formation and esophageal thermal effects with very high-power short duration (vHPSD), and to compare it with high power short duration (HPSD) and low power long duration (LPLD) radiofrequency ablation, using esophageal heating and esophageal temperature probe (ETP) measurements. Methods: A thermochromic gel phantom model of posterior left atrial wall with an embedded ETP was used to assess heating kinetics during radiofrequency ablation (RFA). RFA was performed at 30W/20s (LPLD), 50W/5s (HPSD), 90W/3 and 90W/4s (vHPSD). Continuous ETP temperature was recorded, and thermal mapping of esophageal temperature was performed. Results: 90W/3s (5.17 ± 0.01 mm) and 90W/4s (5.62 ± 0.06 mm) produced broader lesions than 50W/5s (4.17 ± 0.11 mm, p < 0.0001) and 30W/20 s (3.95 ± 0.38 mm, p < 0.01), with similar depth. The ETP underestimated the peak esophageal temperature across all ablation settings with the highest temperature disparity in 30W/20s (3.70 ± 0.60 °C, p = 0.0007), 90W/3s (2.87 ± 0.06 °C, p < 0.0001) and 90W/4s (2.53 ± 0.25 °C, p = 0.0016) groups. Thermal latency was greatest in 90W/4s, followed by 90W/3s, 50W/5s and 30W/20s. Consecutive applications of RFA energy led to heat accumulation and greater esophageal heating, most marked with 90W/4s (41.13 ± 0.12 °C), and 30W/20s (40.90 ± 0.10 °C). Conclusion: vHPSD produces broader lesions with comparable depth which may result in improved PVI lesion contiguity, however, repeated successive applications with vHPSD may lead to greater esophageal heating and inaccurate ETP monitoring due to temperature disparities and thermal latency.

Background: The HeartHealth program is a 6-month SMS text messaging–based support program offered to patients with a recent cardiovascular hospitalization or recent cardiovascular clinic visit in Western Sydney, Australia. Its customized content focuses on cardiovascular risk factors, lifestyle, treatments, and general heart health information. Objective: This study aimed to evaluate the implementation of the HeartHealth program. Methods: A mixed methods study was conducted assessing program reach, effectiveness, implementation, and maintenance using program data, participant feedback surveys, and staff focus group discussions. Consecutive adult patients who had attended cardiology clinics or had been discharged from cardiology hospitalization at Westmead Hospital, between April 2020 and April 2024, were included in the analysis. Content analysis was used to interpret the qualitative data. Results: A total of 23,095 patients were invited, 8804 (38.1%) enrolled into the program, and 7964 out of 8804 (90.5%) completed the 6-month duration. Participants enrolled in the HeartHealth program had a mean age of 58.6 years, 60.3% (5302/8788) were male, and 62.4% (5382/8624) were recruited from an outpatient clinic setting. A total of 851,058 SMS text messages were sent, with 99.41% (846,009/851,058) delivered successfully. A total of 3533 out of 7964 (44.4% of program completers) participants completed the postintervention survey, and 4 HeartHealth staff members participated in a focus group discussion. Among the participants who completed the survey, 60.5% (2137/3533) reported that the program improved the healthiness of their diet, 53.6% (1894/3533) reported improved physical activity levels, and 56.1% (1982/3533) reported that it helped remind them to take their medications. Content analysis of participant feedback identified that the program was effective in prompting participants to change their diet, providing emotional support, reminding them of the importance of behavior change, improving their confidence in managing their health, and keeping participants focused. Key barriers included limited personalization, language options, and SMS text messaging scheduling flexibility. Recommended adaptations focused on enhancing personalization, greater engagement by local clinical teams, and expanding program dissemination. Conclusions: The program had a broad reach, translated to improved patient-reported health behaviors, and provided participants with needed support at low cost and low resource requirements. This analysis highlights the successful implementation and scalability of the HeartHealth program and provides key learnings for health systems that are looking to implement similar programs in the future.

Background: Very high short duration radiofrequency catheter ablation can rapidly achieve pulmonary vein isolation, however safety to the esophagus during posterior left atrial ablation is uncertain. This study looked to characterise lesion formation and esophageal thermal effects with very high-power short duration (vHPSD), and to compare it with high power short duration (HPSD) and low power long duration (LPLD) radiofrequency ablation, using esophageal heating and esophageal temperature probe (ETP) measurements. Methods: A thermochromic gel phantom model of posterior left atrial wall with an embedded ETP was used to assess heating kinetics during radiofrequency ablation (RFA). RFA was performed at 30W/20s (LPLD), 50W/5s (HPSD), 90W/3 and 90W/4s (vHPSD). Continuous ETP temperature was recorded, and thermal mapping of esophageal temperature was performed. Results: 90W/3s (5.17±0.01 mm) and 90W/4s (5.62±0.06 mm) produced broader lesions than 50W/5s (4.17± 0.11 mm, p<0.0001) and 30W/20 s (3.95±0.38 mm, p<0.01), with similar depth. The ETP underestimated the peak esophageal temperature across all ablation settings with the highest temperature disparity in 30W/20s (3.70±0.60°C, p=0.0007), 90W/3s (2.87±0.06°C, p<0.0001) and 90W/4s (2.53±0.25°C, p=0.0016) groups. Thermal latency was greatest in 90W/4s, followed by 90W/3s, 50W/5s and 30W/20s. Consecutive applications of RFA energy led to heat accumulation and greater esophageal heating, most marked with 90W/4s (41.13±0.12°C), and 30W/20s (40.90±0.10°C). Conclusion. vHPSD produces broader lesions with comparable depth which may result in improved PVI lesion contiguity, however, repeated successive applications with vHPSD may lead to greater esophageal heating and inaccurate ETP monitoring due to temperature disparities and thermal latency.

Introduction: Atrio‐esophageal fistula is a rare but devastating complication from thermal esophageal injury during pulmonary vein isolation (PVI). Modifying ablation energy delivery and placement of esophageal temperature probes (ETPs) have been employed to mitigate the risk of thermal esophageal injury. Our study sought to compare the effects of return electrode location, insulation of the ETP, and use of high‐power short‐duration (HPSD) ablation on esophageal temperature, ETP temperature measurement, and thermal lesion dimensions. Methods: A myocardial phantom gel model using thermochromic material was used to approximate the atrio‐esophageal environment. Irrigated ablations were performed at 30 W/20 s (low‐power long duration [LPLD]) and 50 W/5 s (HPSD) with variation of return electrode position and insulation of the ETP. Temperatures were continuously logged, and digital photography with in‐house software was performed to examine lesion dimensions. Results: Distant placement of a return electrode compared to proximal placement decreased peak esophageal temperature ( T _Peak ) across LPLD (41.73°C ± 0.12°C vs. 39.23°C ± 0.15°C; p < 0.0001) and HPSD ablations (39.17°C ± 0.06°C vs. 38.13°C ± 0.06°C; p < 0.0001). Insulation of the ETP reduced T _Peak across LPLD (39.13°C ± 0.25°C vs. 41.73°C ± 0.12°C; p < 0.0001) and HPSD ablation (39.17°C ± 0.06°C vs. 38.27°C ± 0.06°C; p < 0.0001). HPSD ablation produced lower mean T _Peak than LPLD regardless of the location of the return electrode location or insulation of the ETP. Conclusion: HPSD settings, insulation of the ETP, and a distant return electrode placement minimized esophageal heating. These strategies may reduce thermal injury to the esophagus during radiofrequency ablation.