Patient experience of very high power short duration radiofrequency ablation for atrial fibrillation under mild conscious sedation.

BACKGROUND: Very high power short duration (vHPSD) radiofrequency ablation (RFA) may reduce ablation times and improve patient tolerability, permitting pulmonary vein isolation (PVI) under mild conscious sedation (mCS) and promoting same day discharge (SDD). METHODS: First, a retrospective feasibility study was performed at 2 tertiary cardiac centres in the UK. Consecutive cases of first-time PVI using vHPSD ablation with 90 W lesions for up to 4 s were compared against cases performed using standard RF (sRF) and cryoballoon (Cryo) therapy. Subsequently, a prospective study of patients who had vHPSD or Cryo exclusively under mCS was undertaken. Questionnaires based on Likert and visual analogue scales (VAS) were used to measure anxiety, discomfort and pain. RESULTS: In total, 182 patients (59 vHPSD, 62 sRF and 61 Cryo) were included in the retrospective study, with 53 (90%) of vHPSD cases successfully performed under mCS. PVI ablation time in the vHPSD group (5.8 ± 1.7 min) was shorter than for sRF (16.5 ± 6.3 min, p < 0.001) and Cryo (17.5 ± 5.9 min, p < 0.001). Fifty-one vHPSD and 52 Cryo patients were included in the prospective study. PVI ablation time in the vHPSD group was shorter than for the Cryo group (6.4 ± 2.9 min vs 17.9 ± 5.7 min, p < 0.001), but overall procedure duration was longer (121 ± 39 min vs 95 ± 20 min, p < 0.001). There were no differences in the patient experience of anxiety, discomfort or pain. SDD rates were the same in both groups (61% vs 67%, p = 0.49). CONCLUSIONS: vHPSD RFA for PVI can be performed under mCS to achieve SDD rates comparable to cryoablation, without compromising patient experience.

Automatic Extraction of Recurrent Patterns of High Dominant Frequency Mapping During Human Persistent Atrial Fibrillation.

Purpose: Identifying targets for catheter ablation remains challenging in persistent atrial fibrillation (persAF). The dominant frequency (DF) of atrial electrograms during atrial fibrillation (AF) is believed to primarily reflect local activation. Highest DF (HDF) might be responsible for the initiation and perpetuation of persAF. However, the spatiotemporal behavior of DF remains not fully understood. Some DFs during persAF were shown to lack spatiotemporal stability, while others exhibit recurrent behavior. We sought to develop a tool to automatically detect recurrent DF patterns in persAF patients. Methods: Non-contact mapping of the left atrium (LA) was performed in 10 patients undergoing persAF HDF ablation. 2,048 virtual electrograms (vEGMs, EnSite Array, Abbott Laboratories, USA) were collected for up to 5 min before and after ablation. Frequency spectrum was estimated using fast Fourier transform and DF was identified as the peak between 4 and 10 Hz and organization index (OI) was calculated. The HDF maps were identified per 4-s window and an automated pattern recognition algorithm was used to find recurring HDF spatial patterns. Dominant patterns (DPs) were defined as the HDF pattern with the highest recurrence. Results: DPs were found in all patients. Patients in atrial flutter after ablation had a single DP over the recorded time period. The time interval (median [IQR]) of DP recurrence for the patients in AF after ablation (7 patients) decreased from 21.1 s [11.8 49.7 s] to 15.7 s [6.5 18.2 s]. The DF inside the DPs presented lower temporal standard deviation (0.18 ± 0.06 Hz vs. 0.29 ± 0.12 Hz, p < 0.05) and higher OI (0.35 ± 0.03 vs. 0.31 ± 0.04, p < 0.05). The atrial regions with the highest proportion of HDF region were the septum and the left upper pulmonary vein. Conclusion: Multiple recurrent spatiotemporal HDF patterns exist during persAF. The proposed method can identify and quantify the spatiotemporal repetition of the HDFs, where the high recurrences of DP may suggest a more organized rhythm. DPs presented a more consistent DF and higher organization compared with non-DPs, suggesting that DF with higher OI might be more likely to recur. Recurring patterns offer a more comprehensive dynamic insight of persAF behavior, and ablation targeting such regions may be beneficial.

Disparity in implantable cardioverter defibrillator therapy among minority South Asians in the United Kingdom.

OBJECTIVE: There are large geographical differences in implantable cardioverter defibrillator (ICD) implantation rates for reasons not completely understood. In an increasingly multiethnic population, we sought out to investigate whether ethnicity influenced ICD implantation rates. METHODS: This was a retrospective, cohort study of new ICD implantation or upgrade to ICD from January 2006 to February 2019 in recipients of Caucasian or South Asian ethnicity at a single tertiary centre in the UK. Data were obtained from a routinely collected local registry. Crude rates of ICD implantation were calculated for the population of Leicestershire county and were age-standardised to the UK population using the UK National Census of 2011. RESULTS: The Leicestershire population was 980 328 at the time of the Census, of which 761 403 (77.7%) were Caucasian and 155 500 (15.9%) were South Asian. Overall, 2650 ICD implantations were performed in Caucasian (91.9%) and South Asian (8.1%) patients. South Asians were less likely than Caucasians to receive an ICD (risk ratio (RR) 0.43, 95% CI 0.37 to 0.49, p<0.001) even when standardised for age (RR 0.75, 95% CI 0.74 to 0.75, p<0.001). This remained the case for primary prevention indication (age-standardised RR 0.91, 95% CI 0.90 to 0.91, p<0.001), while differences in secondary prevention ICD implants were even greater (age-standardised RR 0.49, 95% CI 0.48 to 0.50, p<0.001). CONCLUSION: Despite a universal and free healthcare system, ICD implantation rates were significantly lower in the South Asian than the Caucasian population residing in the UK. Whether this is due to cultural acceptance or an unbalanced consideration is unclear.

Consideration for primary prevention implantable cardioverter defibrillators differ between specialities.

PURPOSE: Implantable cardioverter defibrillator (ICD) implantation rates remain variable despite established guideline recommendations. This study aims to assess whether being managed by a cardiologist has an impact on whether patients are considered for an ICD for primary prevention of sudden cardiac death. DESIGN/METHODS: Single-centre, retrospective, observational study of patients identified to have severe left ventricular systolic dysfunction (LVSD) on echocardiography (n = 129) between 1 and 30 June 2016 with cross-sectional assessment at 1 year. An assessment of ICD consideration at 1 year following the echocardiogram was documented, in addition to the specialty of the managing physician (group 1-electrophysiologist/heart failure specialist; group 2-all other cardiologists; group 3-non-cardiologist). RESULTS: 129/1173 (11%) transthoracic echocardiographies (s) were identified to have severe LVSD. 52 (40%), 37 (29%) and 40 (31%) were managed by group 1, group 2 and group 3, respectively. Mean age was 74.7 (±12.6) years with a predominance of male gender (70.5%). An ICD was not considered in 47.3%. Those managed by a cardiologist were more likely to be considered for an ICD than a non-cardiologist (63.9% vs 30.0%; OR 4.0, 95% CI 1.8 to 8.8, p = 0.001) with a greater survival at 1 year (89.9% vs 52.5%, OR 8.1 95% CI 3.2 to 20.4, p < 0.001). Group 1 were more likely to consider ICD than group 2 cardiologists (75.0% vs 45.9%; OR 3.5; 95% CI 1.4 to 8.7, p = 0.005). CONCLUSION: There is significant variation between cardiologists and non-cardiologists, as well as within different cardiology subspecialists, when considering the option of ICD therapy for primary prevention.

Postural orthostatic tachycardia syndrome (POTS).

Postural orthostatic tachycardia syndrome (POTS) is a heterogeneous group of conditions characterised by autonomic dysfunction and an exaggerated sympathetic response to assuming an upright position. Up till recently, it was largely under-recognised as a clinical entity. There is now consensus about the definition of POTS as a greater than 30/min heart rate increase on standing from a supine position (greater than 40/min increase in 12-19-year-old patients) or an absolute heart rate of greater than 120/min within 10 min of standing from a supine position and in the absence of hypotension, arrhythmias, sympathomimetic drugs or other conditions that cause tachycardia. We present two cases of POTS, followed by a discussion of its pathogenesis, pathophysiology, epidemiology and management.

Is this an exacerbation of asthma? A cautionary tale.

Asthma exacerbations are a fairly common presentation to emergency departments. However, a careful history, clinical examination and interpretation of investigations may uncover a more serious pathology. We present an interesting case of a 44-year-old man with symptoms suggestive of an asthma exacerbation, who was found to have Churg-Strauss vasculitis/eosinophilic granulomatosis with polyangitis. He had clinical features of a vasculitis, ECG changes and a troponin T level of 7562 ng/L. Renal biopsy confirmed Churg-Strauss vasculitis. Cardiac involvement in Churg-Strauss Syndrome (CSS) is one of the leading causes of mortality. We describe the successful diagnosis and management of a patient with CSS.