Atrial Arrhythmias in Patients With Pulmonary Hypertension.

TOPIC IMPORTANCE: Atrial arrhythmia (AA) are common in patients with pulmonary hypertension (PH) and contribute to morbidity and mortality. Given the growing PH population, understanding the pathophysiology, clinical impact, and management of AA in PH is important. REVIEW FINDINGS: AA occurs in PH with a 5-year incidence of 10% to 25%. AA confers a higher morbidity and mortality, and restoration of normal sinus rhythm improves survival and functionality. AA is thought to develop because of structural alterations of the right atrium caused by changes to the right ventricle (RV) due to elevated pulmonary artery pressures. AA can subsequently worsen RV function. Current guidelines do not provide comprehensive recommendations for the management of AA in PH. Robust evidence to favor a specific treatment approach is lacking. Although the role of medical rate or rhythm control, and the use of cardioversion and ablation, can be inferred from other populations, evidence is lacking in the PH population. Much remains to be determined regarding the optimal management strategy. We present here our institutional approach and discuss areas for future research. SUMMARY: This review highlights the epidemiology and pathophysiology of AA in patients with PH, describes the relationship between AA and RV dysfunction, and discusses current management practices. We outline our institutional approach and offer directions for future investigation.

Hybrid Endo-Epicardial Therapies for Advanced Atrial Fibrillation.

Atrial fibrillation (AF) is a growing health problem that increases morbidity and mortality, and in most patients progresses to more advanced diseases over time. Recent research has examined the underlying mechanisms, risk factors, and progression of AF, leading to updated AF disease classification schemes. Although endocardial catheter ablation is effective for early-stage paroxysmal AF, it consistently achieves suboptimal outcomes in patients with advanced AF. Identification of the factors that lead to the increased risk of treatment failure in advanced AF has spurred the development and adoption of hybrid ablation therapies and collaborative heart care teams that result in higher long-term arrhythmia-free survival. Patients with non-paroxysmal AF, atrial remodeling, comorbidities, or AF otherwise deemed difficult to treat may find hybrid treatment to be the most effective option. Future research of hybrid therapies in advanced AF patient populations, including those with dual diagnoses, may provide further evidence establishing the safety and efficacy of hybrid endo-epicardial ablation as a first line treatment.

Practicality and Safety of Electrical Pulmonary Vein Isolation and Left Atrial Appendage Ligation in Lung Transplant Recipients With Pretransplant Atrial Fibrillation.

Background: Lung transplant surgery creates surgical pulmonary vein isolation (PVI) as a routine part of the procedure. However, many patients with pretransplant atrial fibrillation continue to have atrial fibrillation at 1 y. We hypothesized that the addition of electrical PVI and left atrial appendage isolation/ligation (LAL) to the lung transplant procedure restores sinus rhythm at 1 y in patients with pretransplant atrial fibrillation. Methods: We retrospectively reviewed all adult lung transplant recipients at the University of California Los Angeles from April 2006 to August 2021. All patients with pretransplant atrial fibrillation underwent concomitant PVI/LAL and were compared with lung transplant recipients without preoperative atrial fibrillation. In-hospital outcomes; 1-y survival; and the incidence of stroke, cardiac readmissions, repeat ablations, and sinus rhythm (composite endpoint) were examined at 1 y for the PVI/LAL cohort. Results: Sixty-one lung transplant recipients with pretransplant atrial fibrillation underwent concomitant PVI/LAL. No patient in the PVI/LAL cohort required cardiac-related readmission or catheter ablation for atrial fibrillation within 1 y of transplantation. Freedom from the composite endpoint of death, stroke, cardiac readmission, and repeat ablation for atrial fibrillation at 1 y was 85% (95% confidence interval, 73%-92%) for lung transplant recipients treated with PVI/LAL. Conclusions: The addition of PVI/LAI to the lung transplant operation in patients with pretransplant atrial fibrillation was safe and effective in maintaining sinus rhythm and baseline risk of stroke at 1 y.

Feasibility and Acceptability of Web-Based Structured Oral Examinations for Postgraduate Certification: Mixed Methods Preliminary Evaluation.

BACKGROUND: The COVID-19 pandemic disrupted postgraduate certification examinations globally. The Colleges of Medicine of South Africa continued hosting certification examinations through the pandemic. This was achieved by effecting a rapid transition from in-person to web-based certification examinations. OBJECTIVE: This formative evaluation explored candidates' acceptability of web-based structured oral examinations (SOEs) hosted via Zoom (Zoom Communications Inc). We also reported the audiovisual quality and technical challenges encountered while using Zoom and candidates' overall experience with these examinations conducted during the early part of the COVID-19 pandemic. Additionally, performance in web-based certification examinations was compared with previous in-person certification examinations. METHODS: This mixed methods, single-arm evaluation anonymously gathered candidates' perceptions of web-based SOE acceptability, audiovisual quality, and overall experience with Zoom using a web-based survey. Pass rates of web-based and previous in-person certification examinations were compared using chi-square tests, with a Yates correction. A thematic analysis approach was adopted for qualitative data. RESULTS: Between June 2020 and June 2021, 3105 candidates registered for certification examinations, 293 (9.4%) withdrew, 2812 (90.6%) wrote, and 2799 (99.9%) passed, and 1525 (54.2%) were invited to a further web-based SOE. Examination participation was 96.2% (n=1467). During the first web-based examination cycle (2020), 542 (87.1%) of 622 web-based SOE candidates completed the web-based survey. They reported web-based SOEs as fair (374/542, 69%) and adequately testing their clinical reasoning and insight (396/542, 73.1%). Few would have preferred real patient encounters (173/542, 31.9%) or in-person oral examinations (152/542, 28%). Most found Zoom acceptable (434/542, 80%) and fair (396/542, 73.1%) for hosting web-based SOEs. SOEs resulted in financial (434/542, 80%) and time (428/542, 79%) savings for candidates. Many (336/542, 62%) supported the ongoing use of web-based certification examinations. Only 169 technical challenges in using Zoom were reported, which included connectivity-related issues, poor audio quality, and poor image quality. The thematic analysis identified 4 themes of positive and negative experiences related to web-based SOE station design and content, examination station environment, examiner-candidate interactions, and personal benefits for candidates. Our qualitative analysis identified 10 improvements for future web-based SOEs. Candidates achieved high pass rates in web-based certification examinations in 2020 (1583/1732, 91.39%) and 2021 (850/1067, 79.66%). These were significantly higher (2020: N=8635; χ21=667; P<.001; 2021: N=7988; χ21=178; P<.001) than the previous in-person certification examination pass rate of 58.23% (4030/6921; 2017-2019). CONCLUSIONS: Web-based SOEs conducted by the Colleges of Medicine of South Africa during the COVID-19 pandemic were well received by candidates, and few technical difficulties were encountered while using Zoom. Better performance was observed in web-based examinations than in previous in-person certification examinations. These early findings support the ongoing use of this assessment method.

"We just don't have the resources": Supervisor perspectives on introducing workplace-based assessments into medical specialist training in South Africa.

BACKGROUND: South Africa (SA) is on the brink of implementing workplace-based assessments (WBA) in all medical specialist training programmes in the country. Despite the fact that competency-based medical education (CBME) has been in place for about two decades, WBA offers new and interesting challenges. The literature indicates that WBA has resource, regulatory, educational and social complexities. Implementing WBA would therefore require a careful approach to this complex challenge. To date, insufficient exploration of WBA practices, experiences, perceptions, and aspirations in healthcare have been undertaken in South Africa or Africa. The aim of this study was to identify factors that could impact WBA implementation from the perspectives of medical specialist educators. The outcomes being reported are themes derived from reported potential barriers and enablers to WBA implementation in the SA context. METHODS: This paper reports on the qualitative data generated from a mixed methods study that employed a parallel convergent design, utilising a self-administered online questionnaire to collect data from participants. Data was analysed thematically and inductively. RESULTS: The themes that emerged were: Structural readiness for WBA; staff capacity to implement WBA; quality assurance; and the social dynamics of WBA. CONCLUSIONS: Participants demonstrated impressive levels of insight into their respective working environments, producing an extensive list of barriers and enablers. Despite significant structural and social barriers, this cohort perceives the impending implementation of WBA to be a positive development in registrar training in South Africa. We make recommendations for future research, and to the medical specialist educational leaders in SA.

Cryothermal energy demonstrates shorter ablation time and lower complication rates compared with radiofrequency in surgical hybrid ablation for recurrent ventricular tachycardia.

BACKGROUND: Recurrent ventricular tachycardia (VT) after prior endocardial catheter ablation(s) presents challenges in the setting of prior cardiac surgery where percutaneous epicardial access may not be feasible. OBJECTIVE: The purpose of this study was to compare the outcomes of cryothermal vs radiofrequency ablation in direct surgical epicardial access procedures. METHODS: We performed a retrospective study of consecutive surgical epicardial VT ablation cases. Surgical cases using cryothermal vs radiofrequency ablation were analyzed and outcomes were compared. RESULTS: Between 2009 and 2022, 43 patients underwent either a cryothermal (n = 17) or a radiofrequency (n = 26) hybrid epicardial ablation procedure with direct surgical access. Both groups were similarly matched for age, sex, etiology of VT, and comorbidities with a high burden of refractory VT despite previous endocardial and/or percutaneous epicardial ablation procedures. The surgical access site was lateral thoracotomy (76.5%) in the cryothermal ablation group compared with lateral thoracotomy (42.3%) and subxiphoid approach (38.5%) in the radiofrequency group, with the remainder in both groups performed via median sternotomy. The ablation time was significantly shorter in those undergoing cryothermal ablation vs radiofrequency ablation (11.54 ± 15.5 minutes vs 48.48 ± 23.6 minutes; P < .001). There were no complications in the cryothermal ablation group compared with 6 patients with complications in the radiofrequency group. Recurrent VT episodes and all-cause mortality were similar in both groups. CONCLUSION: Hybrid surgical VT ablation with cryothermal or radiofrequency energy demonstrated similar efficacy outcomes. Cryothermal ablation was more efficient and safer than radiofrequency in a surgical setting and should be considered when surgical access is required.

Clinical predictors and implications of cardiac inflammation detected on positron emission tomography (PET) in patients referred for premature ventricular complex (PVC) ablation.

BACKGROUND: Positron emission tomography computed tomography (PET-CT) is not routinely used for premature ventricular complexes (PVCs). Whether specific clinical factors are associated with abnormal PET-CT results is not clear. METHODS: The treatment courses and baseline characteristics of consecutive patients in a single center between 2012 and 2021, age > 18 years old, and who received 18F-fluorodeoxyglucose (FDG) PET-CT imaging for evaluation of PVCs were retrospectively analyzed. RESULTS: A total of 102 patients was included. Of these, 27 patients (26.4%) had abnormal PET-CT and 61 (59.8%) had normal imaging. Abnormal PET-CT findings were associated with non-sustained ventricular tachycardia (NSVT) (95.2% vs. 52.6%, p = 0.001), higher number of PVC morphologies (2.29 ± 0.7 vs. 1.31 ± 0.6, p < 0.001), greater PVC coupling interval dispersion (72.47 ± 66.4 ms vs. 13.42 ± 17.9 ms, p < 0.001), and greater likelihood of fast heart rate dependent PVCs (78.5% vs. 38.2%, p = 0.017). Fourteen (51.8%) patients had an abnormal PET-CT and abnormal late gadolinium enhancement (LGE). Patients with abnormal PET-CT were more frequently treated with immunosuppression (81.4% vs. 3.2%, p < .0001) than with catheter ablation (11.1% vs. 45.9%, p = 0.002) compared to the normal PET-CT group. Over a median follow-up of 862 days (IQR 134, 1407), PVC burden decreased in both groups [from 23 ± 16% to 9 ± 10% (p < 0.001) in abnormal PET-CT group and from 21 ± 15% to 7 ± 10% (p < 0.001) in normal PET-CT group]. CONCLUSIONS: Abnormal PET-CT findings were more commonly associated with NSVT, multiform PVCs, greater PVC coupling interval dispersion, and fast heart rate dependent PVCs. LGE was not sensitive for detecting inflammation. Immunosuppression was effective in managing PVCs with abnormal PET-CT.

Perceived knowledge of scheme members and their satisfaction with their medical schemes: a cross-sectional study in South Africa.

BACKGROUND: South Africa has a dual healthcare system comprising of private and public sectors covering 16% and 84% of the population, respectively. Medical schemes are the primary source of health insurance in the private sector. The aim of this study was to assess members of medical schemes' perceived knowledge and satisfaction with their medical schemes. METHODS: A cross-sectional survey was conducted using a stratified systematic sample of members of 22 open medical schemes. Medical schemes members completed an online questionnaire on knowledge and satisfaction with their medical schemes. We calculated a composite perceived knowledge and satisfaction score. Descriptive, bivariate and multivariate analysis was conducted. RESULTS: A total of 336 members of medical schemes participated in this study. Respondents generally perceived themselves to have good knowledge of their medical schemes. Eighty-one percent of participants were satisfied with the quality of services received from their designated service providers (DSPs), however, only 9% were satisfied with accessibility of doctors under their DSP arrangement. Twenty-five percent of respondents were satisfied with scheme contributions and only 46% were satisfied with the prescribed minimum benefit package. CONCLUSION: Medical schemes remain a key element of private healthcare in South Africa. The analysis shows that medical schemes, should put more effort into the accessibility of general practitioner under their designated service providers. Furthermore, the prescribed minimum benefits should be reviewed to provide a comprehensive benefits basket without co-payment for members as recommended by the Medical Schemes Act Amendment Bill of 2018.

Detection of inflammation using cardiac positron emission tomography for evaluation of ventricular arrhythmias: An institutional experience.

BACKGROUND: The use of cardiac positron emission tomography-computed tomography (PET-CT) is increasingly used for the detection of underlying inflammation in patients with ventricular arrhythmias (ventricular tachycardia/ventricular fibrillation [VT/VF]), but the role of PET-CT remains undefined, particularly for patients who do not meet Task Force criteria for sarcoidosis. OBJECTIVE: The purpose of this study was to determine the utility of PET-CT for clinical evaluation of VT/VF in patients with nonischemic cardiomyopathy. METHODS: Consecutive patients with nonischemic cardiomyopathy and VT/VF who underwent cardiac PET-CT to detect inflammation between 2012 and 2019 were analyzed for baseline demographic characteristics, imaging results, and outcomes. Patients with known sarcoidosis or other conditions requiring immunosuppressive therapy were excluded. RESULTS: PET-CT was performed in 133 patients with mean age 56.3 ± 13.5 years and left ventricular ejection fraction 43% ± 16.1%, with evidence of myocardial inflammation detected in 32 (23.5%). Patients with myocardial inflammation were managed conservatively with medical therapy including immunosuppressive agents. Ten patients with myocardial inflammation ultimately required catheter ablation for ongoing arrhythmias. There was no significant difference in arrhythmia recurrence between PET-positive and PET-negative groups (37.5% vs 32.4%; P = .43) or in time to recurrence (P = .26), in spite of the disparate management strategies. Gadolinium-enhanced cardiac magnetic resonance imaging was performed in 96 patients (72%); however, magnetic resonance imaging did not detect 31% of cases with active inflammation that were otherwise detected on PET-CT. CONCLUSION: The use of PET-CT significantly improves the detection of underlying myocardial inflammation contributing to ventricular arrhythmias. Management of these patients with immunosuppressive medical therapy is effective for arrhythmia control and may obviate the need for invasive ablation procedures in some patients.

Neuroscientific therapies for atrial fibrillation.

The cardiac autonomic nervous system (ANS) plays an integral role in normal cardiac physiology as well as in disease states that cause cardiac arrhythmias. The cardiac ANS, comprised of a complex neural hierarchy in a nested series of interacting feedback loops, regulates atrial electrophysiology and is itself susceptible to remodelling by atrial rhythm. In light of the challenges of treating atrial fibrillation (AF) with conventional pharmacologic and myoablative techniques, increasingly interest has begun to focus on targeting the cardiac neuraxis for AF. Strong evidence from animal models and clinical patients demonstrates that parasympathetic and sympathetic activity within this neuraxis may trigger AF, and the ANS may either induce atrial remodelling or undergo remodelling itself to serve as a substrate for AF. Multiple nexus points within the cardiac neuraxis are therapeutic targets, and neuroablative and neuromodulatory therapies for AF include ganglionated plexus ablation, epicardial botulinum toxin injection, vagal nerve (tragus) stimulation, renal denervation, stellate ganglion block/resection, baroreceptor activation therapy, and spinal cord stimulation. Pre-clinical and clinical studies on these modalities have had promising results and are reviewed here.

Pulmonary vein and left atrial posterior wall isolation for the treatment of atrial fibrillation: Comparable outcomes for adults with congenital heart disease.

INTRODUCTION: Optimal treatment strategies for ACHD with AF are unknown. This study sought to assess outcomes of pulmonary vein isolation (PVI) ± left atrial (LA), posterior wall isolation (PWI) for adults with congenital heart disease (ACHD), and atrial fibrillation (AF). METHODS: A retrospective review of all cryoballoon (CB) PVI ± PWI procedures at a single center over a 3-year period were performed. Clinical characteristics and outcomes for patients with and without ACHD were compared. The primary outcome was the occurrence of atrial tachyarrhythmia at 12-months postablation after a 90-day blanking period. RESULTS: Three-hundred and sixteen patients (mean: 63 ± 12 years, [63% male]) underwent CB PVI ± PWI during the study, including 31 (10%) ACHD (simple 35%, moderate 39% complex 26%; nonparoxysmal AF in 52%). ACHD was younger (51 vs. 64 years; p < .001) with a lower CHADS2 DS2 -VASc score (1.2 vs. 2.1; p = .001) but had a greater LA diameter (4.9 vs. 4.0 cm; p < .001) and a number of prior cardioversions (0.9 vs. 0.4; p < .001) versus controls. 12-month freedom from recurrent AF was similar for ACHD and controls (76% vs. 80%; p = .6) and remained nonsignificant in multivariate analysis (hazard ratio: 1.8, 95% confidence interval: 0.7-5.1; p = .22). At 12-months postablation, 75% of ACHD versus 93% of control patients were off antiarrhythmic drug therapy (p = .07). CONCLUSION: This study demonstrates younger age and lower conventional stroke risk, yet clinically advanced AF for ACHD relative to controls. CB PVI ± PWI was an effective strategy for the treatment of AF among all forms of ACHD with similar 12-month outcomes as compared to controls.

Arrhythmic Risk Profile and Outcomes of Patients Undergoing Cardiac Sympathetic Denervation for Recurrent Monomorphic Ventricular Tachycardia After Ablation.

Background Cardiac sympathetic denervation (CSD) has been used as a bailout strategy for refractory ventricular tachycardia (VT). Risk of VT recurrence in patients with scar-related monomorphic VT referred for CSD and the extent to which CSD can modify this risk is unknown. We aimed to quantify arrhythmia recurrence risk and impact of CSD in this population. Methods and Results Adjusted competing risk time to event models were developed to adjust for risk of VT recurrence and sustained VT/implantable cardioverter-defibrillator shocks after VT ablation based on patient comorbidities at the time of VT ablation. Adjusted VT and implantable cardioverter-defibrillator shock recurrence rates were estimated for the subgroup who subsequently required CSD after ablation. The expected adjusted recurrence rates were then compared with the observed rates after CSD. Data from 381 patients with scar-mediated monomorphic VT who underwent VT ablation were analyzed, excluding patients with polymorphic VT. Sixty eight patients underwent CSD for recurrent VT. CSD reduced the expected adjusted VT recurrence rate by 36% (expected rate of 5.61 versus observed rate of 3.58 per 100 person-months, P=0.01) and the sustained VT/implantable cardioverter-defibrillator shock rates by 34% (expected rate of 4.34 versus observed 2.85 per 100 person-months, P=0.03). The median number of sustained VT/implantable cardioverter-defibrillator shocks in the year before versus the year after CSD was reduced by 90% (10 versus 1, P<0.0001). Conclusions Patients referred for CSD for refractory scar-mediated monomorphic VT are at a higher risk of VT recurrence after ablation as compared with those not requiring CSD, mostly because of their cardiac comorbidities. CSD significantly reduced both the expected risk of recurrences and VT burden.

Left atrial posterior wall isolation in conjunction with pulmonary vein isolation using cryoballoon for treatment of persistent atrial fibrillation (PIVoTAL): study rationale and design.

BACKGROUND: There is growing evidence in support of pulmonary vein isolation (PVI) with concomitant posterior wall isolation (PWI) for the treatment of patients with symptomatic persistent atrial fibrillation (persAF). However, there is limited data on the safety and efficacy of this approach using the cryoballoon. OBJECTIVE: The aim of this multicenter, investigational device exemption trial (G190171) is to prospectively evaluate the acute and long-term outcomes of PVI versus PVI+PWI using the cryoballoon in patients with symptomatic persAF. METHODS: The PIVoTAL is a prospective, randomized controlled study ( ClinicalTrials.gov : NCT04505163) in which patients with symptomatic persAF refractory/intolerant to ≥ 1 class I-IV antiarrhythmic drug, undergoing first-time catheter ablation, will be randomized to PVI (n = 183) versus PVI+PWI (n = 183) using the cryoballoon in a 1:1 fashion. The design will be double-blind until randomization immediately after PVI, beyond which the design will transform into a single-blind. PVI using cryoballoon will be standardized using a pre-specified dosing algorithm. Other empiric ablations aside from documented arrhythmias/arrhythmias spontaneously induced during the procedure will not be permitted. The primary efficacy endpoint is defined as AF recurrence at 12 months, after a single procedure and a 90-day blanking period. Arrhythmia outcomes will be assessed by routine electrocardiograms and 7-14 day ambulatory electrocardiographic monitoring at 3, 6, and 12 months post-ablation. CONCLUSION: The PIVoTAL is a prospective, randomized controlled trial designed to evaluate the outcomes of PVI alone versus PVI+PWI using the cryoballoon, in patients with symptomatic persAF. We hypothesize that PVI+PWI will prove to be superior to PVI alone for prevention of AF recurrence.

Non-invasive stereotactic body radiation therapy for refractory ventricular arrhythmias: an institutional experience.

BACKGROUND: Initial studies have reported excellent safety and efficacy for stereotactic body radiation therapy (SBRT) in patients with refractory ventricular tachycardia (VT). METHODS: This is a single-center retrospective analysis of eight consecutive patients who underwent SBRT for refractory, scar-related VT. The anatomic target for radioablation was defined based on surface 12-lead ECG VT morphology, cardiac magnetic resonance imaging, and electroanatomic mapping data when available. The target volume treated and the prescribed radiation dose (15-25 Gy) was based on the combined clinical assessment of the cardiac electrophysiologist and radiation oncologist. Ventricular arrhythmias, radiation-related outcomes, and adverse events were monitored at follow-up. RESULTS: Eight patients underwent nine SBRT sessions. All patients were male with an average age of 75 ± 7.3 years and mean ejection fraction of 21 ± 7%. SBRT was performed with delivery of an average of 22.2 ± 3.6 Gy in a single session with a procedure time of 18.2 ± 6.0 min. All but one session was performed on an inpatient basis. No acute complications occurred. During a median follow-up of 7.8 months (IQR 4.8, 9.9), ICD therapies decreased from median 69.5 (43.5, 115.8) pre-SBRT to 13.3 (IQR 7.7, 35.8) post-SBRT (p = 0.036). There were three patient deaths in the follow-up period, unrelated to SBRT. Apparent clinical benefit occurred 33% of the time after SBRT. CONCLUSIONS: The patients experienced overall reduction in VT burden following SBRT, though not with the immediate effect seen in other patient series. Further studies (basic, translational, and clinical) are essential to determine the benefit of SBRT and if so, the optimal protocols and patient selection.