A retrospective evaluation of catheter ablation in atrial flutter post cardiac transplantation.

BACKGROUND: Atrial flutter is the most common arrhythmia post cardiac transplantation. Observational studies in the non-transplant population have shown prognostic benefit with catheter ablation; however, there are no data in the heart transplant population. OBJECTIVES: This study evaluated the experience of catheter ablation in atrial flutter post cardiac transplantation. METHODS: A retrospective review of experience of late onset atrial flutter at the Freeman Hospital, Newcastle-upon-Tyne, UK, between 1985 and January 2020. RESULTS: Sixty eight of the 722 patients who survived 6 months post cardiac transplantation developed late atrial flutter giving an incidence of 9.4%. Thirty-two patients were managed with ablation with treatment largely determined by time of flutter onset. Kaplan Meier estimates for arrhythmia free survival post first ablation for organized atrial arrhythmias was 83.3% at 1 year. Kaplan-Meier estimates for median survival post onset of atrial arrhythmias treated with ablation was 11.34 years (95% CI 8.00-14.57), compared to 5.79 years in patients managed medically (95%CI 2.26-9.32) (P = .026). CONCLUSIONS: Atrial flutter is an important late complication of cardiac transplantation. Patients treated with ablation in the modern era had increased survival compared to a historical cohort.

Syncope in the Older Person.

Syncope in the older person carries a high morbidity, mortality, and health economic burden. While neurally mediated disorders and orthostatic hypotension account for the majority of syncopal episodes in this age group, around a third of causes are cardiac, predominantly arrhythmic. Clinicians need to be aware of the management of potential comorbid issues such as osteoporosis and cognitive impairment and if not in a position to act on them, ensure that appropriate specialist help is sought. Further work is needed to understand the pathophysiology and hence the management of syncope in the older patient, with ongoing studies helping to tease out some of the treatment controversies.

Update on the role of pacemaker therapy in vasovagal syncope and carotid sinus syndrome.

Vasovagal syncope (VVS) and carotid sinus syndrome (CSS) are related, neurally mediated disorders with different clinical features and treatment implications. Pacemaker intervention studies in both syndromes are hampered by a dearth of randomized, controlled (particularly with placebo) studies, unfortunate premature termination of studies, and variation in both the clinical presentation and cardiovascular profile of patients enrolled. Given this relatively limited evidence base, pacing therapy in VVS should be reserved for older sufferers with relatively frequent symptoms and spontaneous asystole documented during real-life monitoring. The long term course of patients paced for vasovagal syncope needs clarification, both in terms of symptom and device-related burden, while a comprehensive health economic evaluation of the costs and benefits of such an invasive approach for this usually benign condition is essential. It will also be important to determine the efficacy of closed loop stimulation pacing in an adequately powered study, including a comparison with standard pacing. Pacing should be considered in those with unexplained syncope with reproduction of symptoms during a cardio-inhibitory or mixed response to carotid sinus massage (asystole >3 s), though the evidence base for this recommendation is firmly in the consensus rather than pragmatic randomized controlled trial camp. Patients presenting with unexplained falls and drop attacks, particularly where injuries are prominent and where patients cannot give a clear account of their fall ("I just ended up on the floor, didn't slip or trip"), should also be considered for pacing. Pacing is not recommended for the vasodepressor sub-type of CSS.

Interatrial rupture of a non-coronary sinus of Valsalva aneurysm: a rare presentation of a rare disorder.

A 65-year-old male was referred to our team after the incidental finding of a large non-coronary sinus of Valsalva aneurysm on computed tomography (CT)-scan of the thorax. Further imaging with transesophageal echocardiography (TOE) excluded intracardiac shunting. Unusually, the aneurysm had ruptured into the interatrial septum and was seen to be compressing both atria. At operative intervention, a 20 mm defect which had replaced the non-coronary sinus was repaired using a patch graft. An aneurysm of an aortic sinus is a rare disorder, and a rupture of a non-coronary sinus typically results in the formation of a fistulous tract in the right atrium. These images highlight an unusual case of a non-coronary sinus of Valsalva aneurysm which ruptured into the interatrial septum (IAS), and demonstrate the benefit of multi-modality cardiac imaging in guiding surgical repair.

Do implantable cardioverter defibrillators improve survival in patients with severe left ventricular systolic dysfunction after coronary artery bypass graft surgery?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question addressed was whether implantable cardioverter defibrillators (ICD) improve survival in patients with severe left ventricular systolic dysfunction (LVSD) after coronary artery bypass graft (CABG) surgery. ICDs are designed to terminate potentially fatal cardiac tachyarrhythmias. A right ventricular lead is mandatory for detection, pacing and defibrillation capabilities. Dual chamber ICDs have an additional right atrial lead and are used for patients with conventional atrioventricular pacing indications. More sophisticated, biventricular devices exist to provide cardiac resynchronisation therapy (CRT) in addition to defibrillation (CRT-D). ICDs have been extensively investigated in patients with LVSD post myocardial infarction and in patients with non-ischaemic cardiomyopathy for both secondary prevention (history of ventricular arrhythmias) and primary prevention (deemed high risk for ventricular arrhythmias). This best evidence topic aims to review the evidence and its applicability to patients post CABG. Nine hundred and sixteen papers were identified using the search method outlined. Eight randomised controlled trials, two meta-analyses, and one non-randomised trial, in addition to international guidelines presented the best evidence to answer the clinical question. The current evidence base and guidelines suggest that ICDs should be considered for all patients with LVSD [ejection fraction (EF) ≤30-40%] receiving optimal pharmacological management, who are ≥40 days post MI [four weeks for National Institute for Health and Clinical Excellence (NICE)] and in New York Heart Association (NYHA) class I-III. UK NICE guidelines require in addition; non-sustained ventricular tachycardia (NSVT) on a Holter monitor and inducible ventricular tachycardia at electrophysiological study for EF between 30 and 35%; or a QRS >120 ms if EF <30%. The North American guidelines recommend EF <30% as a threshold for those with NYHA class I symptoms. The evidence is applicable to patients post CABG, provided all the other criteria are met. European Society of Cardiology (ESC) guidelines recommend waiting at least three months (consensus opinion) after revascularisation prior to assessment for an ICD, to allow time for potential recovery of ventricular function.

In patients undergoing aortic valve replacement, what factors predict the requirement for permanent pacemaker implantation?

A best evidence topic in cardiac surgery was written according to a structured protocol. The question was to determine what preoperative, perioperative and postoperative factors influence the requirement for permanent pacemaker (PPM) implantation postisolated aortic valve replacement (AVR). Transcatheter aortic valve intervention was not included in this analysis. Using the reported search method outlined below, 705 papers were found. No randomised controlled trials, meta-analyses or registries were identified. Seven single-centre retrospective observational studies represent the best evidence on the subject. The author, journal, date and country of publication, level of evidence, patient group studied, study type, outcomes and results were tabulated. The incidence of PPM implantation following AVR varied from 3.0% to 11.8% (mean 7.0%, median 7.2%). Current best available evidence suggests that baseline evidence of conducting system disease - first degree atrioventricular block (AVB), left anterior hemiblock, right bundle branch block (RBBB) or left bundle branch block (LBBB) is the most powerful independent predictor of PPM requirement following AVR. Other important predictors are surgery for aortic regurgitation, preoperative myocardial infarction and longer perioperative cardiopulmonary bypass time. No consistent postoperative factors were identified. The mean time to PPM implant postAVR ranged from 6 to 13 days in the four studies that reported it. Current European Society of Cardiology guidelines recommend a period of seven days of persistent AVB postsurgery prior to PPM implantation.

Postoperative permanent pacemaker implantation in patients undergoing trans-catheter aortic valve implantation: what is the incidence and are there any predicting factors?

A best evidence topic was written according to a structured protocol. The issue was to determine the incidence and predictors of postoperative permanent pacemaker (PPM) implantation in patients undergoing trans-catheter aortic valve implantation (TAVI) for symptomatic calcific aortic stenosis and to compare this to the known risks of this complication following surgical aortic valve replacement (AVR). Using the reported search method 3071 articles were identified, of which 94 were relevant to the procedure of TAVI and 14 were deemed to represent the best evidence. All 14 studies, including both multi-centre registries and single-centre retrospective case series containing ≥30 patients, reported incidence of postoperative PPM implantation. Five of these studies also assessed predictors of the need for postoperative PPM implantation. The author, journal, date and country of publication, study type, level of evidence, patient group, outcomes and results were tabulated for these studies. We conclude that the current best available evidence suggests that the mean incidence of PPM implantation following TAVI is 14.2% (range 0-34%, median 9.7%), although this appears higher with the CoreValve prosthesis (five studies, mean 20.8%, range 9.3-30.0%) than with the Edwards-Sapien prosthesis (six studies, mean 5.4%, range 0-10.1%). The mean incidences of PPM implantation overall and when using the CoreValve prosthesis are higher than the mean incidence of 7.0% (range 3-11.8%, median 7.2%) following conventional AVR and may be explained by distinct differences between the patient groups involved and the procedure performed. Indications for PPM implantation appear to occur early in the postoperative period following TAVI and there is little evidence of recovery following atrioventricular block (AVB). New onset persistent left bundle branch block is common following TAVI but the significance and follow-up required is unclear. Independent predictors of PPM requirement following TAVI include use of the CoreValve prosthesis and evidence of conduction system dysfunction, either pre-existing right bundle branch block or AVB at the time of TAVI. All patients should be made aware of the high risk of PPM implantation with TAVI.

Implantable loop recorders in the investigation of unexplained syncope: a state of the art review.

Since its introduction 15 years ago, the implantable loop recorder (ILR) has become the investigative tool of choice in recurrent unexplained syncope following negative initial investigations. This is based on very few randomised controlled clinical trials and modestly sized observational studies. Further controlled data are required to inform clinical practice with attention focused on empowering ILR-guided diagnosis, establishing the optimal timing of ILR use in syncope and embracing new technological advancements.