2023 Cardiac Society of Australia and New Zealand Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation.

Catheter ablation for atrial fibrillation (AF) has increased exponentially in many developed countries, including Australia and New Zealand. This Expert Position Statement on Catheter and Surgical Ablation for Atrial Fibrillation from the Cardiac Society of Australia and New Zealand (CSANZ) recognises healthcare factors, expertise and expenditure relevant to the Australian and New Zealand healthcare environments including considerations of potential implications for First Nations Peoples. The statement is cognisant of international advice but tailored to local conditions and populations, and is intended to be used by electrophysiologists, cardiologists and general physicians across all disciplines caring for patients with AF. They are also intended to provide guidance to healthcare facilities seeking to establish or maintain catheter ablation for AF.

Left atrial, pulmonary vein, and left atrial appendage anatomy in Indigenous individuals: Implications for atrial fibrillation.

BACKGROUND: Indigenous Australians experience a greater burden of AF. Whether this is in-part due to differences in arrhythmogenic structures that appear to contribute to AF differences amongst other ethnicities is not known. METHODS: We studied forty individuals matched for ethnicity and other AF risk factors. Computed tomography imaging was used to characterise left atrial (LA), pulmonary vein (PV), and left atrial appendage (LAA) anatomy. RESULTS: There were no significant differences in LA diameters or volumes between Indigenous and non-Indigenous Australians. Similarly, we could not detect any consistent differences in PV number, morphology, diameters, or ostial characteristics according to ethnicity. LAA analyses suggested that Indigenous Australians may have a greater proportion of non chickenwing LAA type, and a tendency for eccentric, oval-shaped LAA ostia; however, there were no other differences seen with regards to LAA volume or depth. Indexed values for LA, PV and LAA anatomy corrected for body size were broadly similar. CONCLUSIONS: In a cohort of individuals matched for AF risk factors, we could find no strong evidence of ethnic differences in LA, PV, and LAA characteristics that may explain a predisposition of Indigenous Australians for atrial arrhythmogenesis. These findings, in conjunction with our previous data showing highly prevalent cardiometabolic risk factors in Indigenous Australians with AF, suggest that it is these conditions that are more likely responsible for the AF substrate in these individuals. Continued efforts should therefore be directed towards risk factor management in an attempt to prevent and minimise the effects of AF in Indigenous Australians.

Assessment of ablation catheter contact on valve annulus: Implications on accessory pathway ablation.

BACKGROUND: Catheter-tissue contact force is an important factor influencing lesion size and efficacy and thereby potential for arrhythmia recurrence following accessory pathway (AP) radiofrequency ablation. We aim to evaluate adequacy and perception of catheter contact on the tricuspid and mitral annuli. METHODS: Data were collected from 42 patients undergoing catheter ablation. Operators were blinded to contact force information and reported perceived contact (poor, moderate, or good) while positioning the catheter at four tricuspid annular sites (12, 9, 6 and 4 o'clock positions; abbreviated as TA12, TA9, TA6 and TA4) and three mitral annular sites (3, 5 and 7 o'clock positions; abbreviated as MA3, MA5 and MA7) through long vascular sheaths. RESULTS: The highest and lowest mean contact forces were obtained at MA7 (13.3 ±â€¯1.7 g) and TA12 (3.6 g ±â€¯1.3 g) respectively. Mean contact force on tricuspid annulus (6.1 g ±â€¯0.9 g) was lower than mitral annulus (9.8 ±â€¯0.9 g) locations (p = 0.0036), with greater proportion of sites with <10 g contact force (81.7% vs 60.4%; p = 0.0075). Perceived contact had no impact on measured mean contact force for both mitral and tricuspid annular positions (p = 0.959 and 0.671 respectively). There was correlation of both impedance and atrial electrogram amplitude with contact force, though insufficient to be clinically applicable. CONCLUSION: A high proportion of annular catheter applications have low contact force despite being performed with long vascular sheaths in the hands of experienced operators. In addition, there was no impact of operator perceived contact force on actual measured contact force. This may carry implications for success of AP ablation.

Prescribers' practice of assessing arrhythmia risk with QT-prolonging medications.

AIMS: This study aimed to assess prescribers' monitoring for arrhythmic risk with QT-prolonging medications (LQT drugs). METHODS: Over a 6-month period, all inpatients under the care of Cardiologists (Cohort A) and General Physicians (Cohort B) at Aberdeen Royal Infirmary who were prescribed drugs with known risk of Torsades de Pointes (TdP) were identified. Admission and repeat electrocardiograms (ECG) after 48 h of commencing a LQT drug were examined. Actions taken if QTc was prolonged and drug-drug interactions were examined. A risk estimate on the UK hospital population was calculated. RESULTS: Of the 4133 patients admitted during the study period, 234 (6%) patients were prescribed a LQT drug. There were 100 (43%) patients in Cohort A and 134 (57%) patients in Cohort B. Of those admitted with a pre-existing LQT drug prescription, an ECG was performed in 167 (96%) of patients and QTc prolongation was identified in 59 (34%). Of those who received a new prescription of LQT drug, 23 (38%) had QTc prolongation and more patients in Cohort A than Cohort B had a repeat ECG within 48 h (84% vs. 11%, P < 0.0001). QTc prolongation was only recognized in 6 (14%) and 2 (5%) patients in cohorts A and B, respectively. Only one patient at risk of drug interaction had QTc prolongation. None of our patients had documented TdP in hospital. Extrapolating these findings to the UK hospital population, at least 204 and <17-175 patients on cardiac and noncardiac LQT drugs, respectively, might be expected to have TdP each year. CONCLUSION: Recognition of acquired QTc prolongation is poor. Clinician education and an electronic prescribing system may improve this situation.

Cardiac sarcoid or arrhythmogenic right ventricular cardiomyopathy: a role for positron emission tomography (PET)?

We present a case of cardiac sarcoidosis of insidious onset mimicking arrhythmogenic right ventricular cardiomyopathy. Our patient initially presented with systemic sarcoidosis but later developed palpitations. The similarity in clinical presentation and cardiac magnetic resonance findings in both conditions posed a challenge in differentiating between the two in the absence of histological diagnosis. We highlighted the role of positron emission tomography in aiding a diagnosis.

Complication rates of colonic polypectomy in relation to polyp characteristics and techniques: a district hospital experience.

BACKGROUND: Colonic polypectomy reduces the subsequent rate of development of colonic cancer but is not without its risks. We aimed to examine our complication rates in relation to the characteristics of polyps and techniques employed. METHODS: A database for all colonic polypectomies performed over a 3½-year period between 2006 and 2009 was matched against all patients readmitted after an endoscopy. Serious complications post-polypectomy were defined as events leading to readmission within 14 days. RESULTS: We performed 2106 polypectomies on 1252 patients in this period. Fourteen patients or 24 (1.1%) polypectomies experienced complications. Two patients (0.09%) experienced perforation, 10 (0.47%) had bleeding and 3 (0.14%) had post-polypectomy syndromes. Our bleeding rate was 1:211, lower than the national standard of 1:100. No deaths were reported. Complication rates rose from 1% in the smallest group (1-10 mm) to 4.9% in the largest (>31 mm) but the difference was not statistically significant (p=0.067). Right-colon polypectomies had a higher tendency of developing post-polypectomy syndrome and bleeding (p=0.002). Complication rates in snare polypectomies were not significantly different from that of hot biopsies (p=0.64). However, endoscopic mucosal resections (EMR) had significantly more complications compared to snares (p=0.045) and hot biopsies (p=0.026). CONCLUSION: We achieved lower bleeding rates than that published nationally. Hot biopsies did not carry a higher risk unlike EMRs. Although polyp size may be an important risk factor, statistical significance was not met. Ascending and transverse colon polypectomies carried the highest risks of complications.

The impact of NICE (UK) recommendations on outcomes of cardiac pacemaker implantations--a single-centre, district hospital experience.

AIMS: The National Institute for Health and Clinical Excellence (NICE) recommends the use of dual-chamber pacemakers for all patients with bradycardia with a few exceptions. We aimed to evaluate our compliance to the guidelines and the implications of different pacing modalities on follow-up outcomes. METHODS: We conducted two retrospective studies involving a total of 316 patients. The first study conducted over a 36-month period examined our performance prior to the introduction of the NICE guidance. The more recent second study conducted over a 12-month period examined our compliance to the NICE guidance upon its introduction and adoption. Data were analysed in separate groups according to pacemaker types. Symptom control and mortality were measures on follow-up outcomes. RESULTS: Our compliance to the guidance increased from 72% in the former study to 78% in the latter study (P = 0.17). Symptom control and mortality were not significantly different between the two studies. Combining both studies, fewer NICE-compliant patients complained of persisting symptoms after 1 year (P = 0.36). Although fewer deaths were observed in the compliant group, this again was not statistically significant (P = 0.10). Although age was not a criteria in selecting a device, younger patients were more likely to receive a pacemaker according to NICE recommendations (P = 0.001). CONCLUSIONS: We achieved a near 80% level of compliance to NICE guidance. Our non-NICE-compliant patients did not have a poorer outcome than those who were compliant. The decision to insert single- or dual-chamber pacemakers is often multifactorial and individual doctors may have different practices.

Experience of atrial fibrillation ablation in a new cardiac centre using three-dimensional mapping and multielectrode duty-cycled radiofrequency ablation.

BACKGROUND: Catheter ablation is widely used to treat symptomatic atrial fibrillation (AF) refractory to drug therapy; and can be facilitated by a number of different techniques. AIMS: To evaluate our performance as a new centre for AF ablation and to evaluate the efficacy of different AF ablation techniques. METHODS: We employed three techniques in AF ablations; the three-dimensional (3D) mapping approaches (CARTO or Ensite NavX) or multielectrode catheter duty-cycled radiofrequency ablation (pulmonary vein ablation catheter [PVAC]). The immediate restoration of sinus rhythm was considered as acute success; while success at 6 months was determined by the maintenance of sinus rhythm on Holter monitoring. RESULTS: Between March 2008 and March 2010, 109 patients underwent AF ablations (mean age: 58 years; 72% male). Six-month success rates did not differ significantly between CARTO and NavX (40% vs 38%; P=0.81), but the PVAC group achieved greater success than the two 3D-mapping groups combined (68% vs 39%; P=0.004). Paroxysmal AF patients demonstrated greater 6-month success than persistent AF patients (P=0.005); and although the ratio of paroxysmal to persistent AF patients was slightly higher among the PVAC group, logistic regression confirmed PVAC and paroxysmal AF as predictors of success. Single-procedure success at 6 months was 48%. Including redo-ablations, some performed beyond the study period, our overall success rate at 6 months was 65%. Four patients experienced complications, but there were no deaths. CONCLUSION: Despite being a new centre with relative inexperience, we achieved success rates comparable to those of established tertiary centres. PVAC performed significantly better than the two 3D-mapping approaches.

Menstruation angina: a case report.

INTRODUCTION: Menstruation is commonly associated with migraine and irritable bowel but is rarely correlated with angina or myocardial ischaemia. Only a small number of cases have been reported suggesting a link between menstruation and myocardial ischaemic events. CASE PRESENTATION: A case of menstruation angina is reported in order to raise awareness of this association. A 47-year-old South Asian woman presented with recurrent chest pains in a monthly fashion coinciding with her menstruations. Each presentation was associated with troponin elevation. Angioplasty failed to resolve her symptoms but she eventually responded to hormonal therapy. CONCLUSIONS: The possibility of menstruation angina should always be taken into account in any female patients from puberty to menopause presenting with recurrent chest pains. This can allow an earlier introduction of hormonal therapy to arrest further myocardial damage.