Stephen P. Page

Maintenance of sinus rhythm with an ablation strategy in patients with atrial fibrillation is associated with a lower risk of stroke and death

Objective To investigate whether catheter ablation of atrial fibrillation (AF) reduces stroke rate or mortality. Methods An international multicentre registry was compiled from seven centres in the UK and Australia for consecutive patients undergoing catheter ablation of AF. Long-term outcomes were compared with (1) a cohort with AF treated medically in the Euro Heart Survey, and (2) a hypothetical cohort without AF, age and gender matched to the general population. Analysis of stroke and death was carried out after the first procedure (including peri-procedural events) regardless of success, on an intention-to-treat basis. Results 1273 patients, aged 58±11 years, 56% paroxysmal AF, CHADS2 score 0.7±0.9, underwent 1.8±0.9 procedures. Major complications occurred in 5.4% of procedures, including stroke/TIA in 0.7%. Freedom from AF following the last procedure was 85% (76% off antiarrhythmic drugs) for paroxysmal AF, and 72% (60% off antiarrhythmic drugs) for persistent AF. During 3.1 (1.0–9.6) years from the first procedure, freedom from AF predicted stroke-free survival on multivariate analysis (HR=0.30, CI 0.16 to 0.55, p<0.001). Rates of stroke and death were significantly lower in this cohort (both 0.5% per patient-year) compared with those treated medically in the Euro Heart Survey (2.8% and 5.3%, respectively; p<0.0001). Rates of stroke and death were no different from those of the general population (0.4% and 1.0%, respectively). Conclusion Restoration of sinus rhythm by catheter ablation of AF is associated with lower rates of stroke and death compared with patients treated medically.

A Randomized Controlled Trial of Catheter Ablation Versus Medical Treatment of Atrial Fibrillation in Heart Failure (The CAMTAF Trial)

Background—Restoring sinus rhythm in patients with heart failure (HF) and atrial fibrillation (AF) may improve left ventricular (LV) function and HF symptoms. We sought to compare the effect of a catheter ablation strategy with that of a medical rate control strategy in patients with persistent AF and HF. Methods and Results—Patients with persistent AF, symptomatic HF, and LV ejection fraction <50% were randomized to catheter ablation or medical rate control. The primary end-point was the difference between groups in LV ejection fraction at 6 months. Baseline LV ejection fraction was 32±8% in the ablation group and 34±12% in the medical group. Twenty-six patients underwent catheter ablation, and 24 patients were rate controlled. Freedom from AF was achieved in 21/26 (81%) at 6 months off antiarrhythmic drugs. LV ejection fraction at 6 months in the ablation group was 40±12% compared with 31±13% in the rate control group (P=0.015). Ablation was associated with better peak oxygen consumption (22±6 versus 18±6 mL/kg per minute; P=0.014) and Minnesota living with HF questionnaire score (24±22 versus 47±22; P=0.001) compared with rate control. Conclusions—Catheter ablation is effective in restoring sinus rhythm in selected patients with persistent AF and HF, and can improve LV function, functional capacity, and HF symptoms compared with rate control. Clinical Trial Registration—URL: http://www.clinicaltrials.gov. Unique identifier: NCT01411371

Catheter Ablation for Atrial Fibrillation on Uninterrupted Warfarin: Can It Be Done Without Echo Guidance?

AF Ablation on Uninterrupted Warfarin. Introduction: Catheter ablation for atrial fibrillation is an effective treatment for symptomatic patients who have failed drug therapy. Recent studies using intracardiac echocardiography have demonstrated that ablation can be performed safely on uninterrupted warfarin and may be superior to bridging low molecular weight heparin (LMWH). We sought to assess the safety of an uninterrupted warfarin protocol using a simplified ablation protocol in a prospective controlled study.

Impact of variant pulmonary vein anatomy and image integration on long-term outcome after catheter ablation for atrial fibrillation.

AIMS To investigate the impact of variant pulmonary vein (PV) anatomy and the use of three-dimensional image integration (3D-II) on long-term efficacy of catheter ablation for atrial fibrillation (AF). METHODS Consecutive procedures from 2002 to 2007 were analysed from a prospective database. All patients underwent wide area circumferential ablation, with linear lesions added and complex fractionated electrograms targeted for persistent AF. Imaging was segmented on Carto to assess PV anatomy. RESULTS Three hundred and fifty patients underwent 1.9 ± 0.9 procedures. The mean age was 57 ± 11 years, 73% males, and 55% paroxysmal AF. Freedom from AF/atrial tachycardia was 42% for paroxysmal AF and 20% for persistent AF at 3.1 years after the first procedure, or 86 and 66%, respectively, at 2.5 years after the last procedure. The Kaplan-Meier analysis showed a trend towards improved single-procedure efficacy with 3D-II (8.9% difference, P = 0.087) and a reduction in the number of procedures per patient from 2.1 ± 1.1 to 1.8 ± 0.9 (P < 0.0001). The use of 3D-II improved single-procedure efficacy with Carto (13.3% difference, P = 0.018), but not with Ensite NavX. Variant PV anatomy was identified in 28% and was associated with a lower single-procedure efficacy (10.0% difference, P = 0.024) but with no effect on final outcome. Multivariate analysis confirmed the impact of 3D-II [hazard ratio (HR) for recurrence of AF 0.67, P = 0.020] and variant PV anatomy (HR 1.37, P = 0.044). CONCLUSION The use of 3D-II improves single-procedure efficacy of PV isolation for AF. Variant PV anatomy was associated with a lower single-procedure success rate.

Long-term benefits of pacing in obstructive hypertrophic cardiomyopathy

Hypertrophic cardiomyopathy (HCM), the most common inherited cardiac disorder, is defined by unexplained left ventricular hypertrophy. HCM is associated with a range of clinical expressions, including severe limitation, premature sudden death and asymptomatic survival to advanced age.1 A subset of people have left ventricular (LV) outflow tract obstruction (LVOTO), where systolic anterior motion of the mitral valve results in mitral regurgitation and mitral-septal contact that impedes LV ejection. Approximately 25% have obstruction evident at rest and many others have obstruction provoked by exercise. Although not all patients with obstruction are symptomatic, many are limited by chest pain, breathlessness, dizziness and syncope; LVOTO is an important therapeutic target. Initial treatment with negative inotropes such as β blockers, verapamil and disopyramide often fails to control symptoms or is associated with intolerable side effects.1 Surgical left ventricular myectomy (LVM) was adopted as the first effective treatment for symptom relief2; with short atrioventricular (AV) delay pacing3 and alcohol septal ablation (ASA)4 subsequently developed as less invasive options. Following observations of a potentially beneficial haemodynamic effect of pacing, placebo-controlled studies in the late 1990s divided expert opinion and pacing failed to gain widespread acceptance.5–7 Re-examination of the role of pacing in HCM is desirable for several reasons. First, the efficacy of ASA and LVM remain untested by randomised trial. Second, the randomised trials of pacing therapy have important limitations. Third, new device technology introduces novel treatment opportunities. Fourth, some patients are unsuitable for either ASA or LVM. Finally, recent data have demonstrated long-term symptomatic benefit from pacing in as many as 80% of patients.8–10 In obstructive HCM, right ventricular (RV) pacing reduces LVOTO acutely and chronically. The history of the development of DDD pacing for this indication and its likely mechanisms of action have been expertly summarised …

Improved Electrogram Attenuation during Ablation of Paroxysmal Atrial Fibrillation with the Hansen Robotic System

Background: Robotic catheter ablation aims to improve outcomes after ablation of atrial fibrillation (AF) through improved lesion quality. This study examined electrogram attenuation as a measure of efficacy in response to robotic (ROB) and manual (MAN) ablation.

Epicardial catheter ablation for ventricular tachycardia in heparinized patients

AIMS In patients undergoing epicardial catheter ablation of ventricular tachycardia (VT), current guidelines recommend obtaining pericardial access prior to heparinization to minimize bleeding complications. Consequently, access is obtained before endocardial mapping (leading to unnecessary punctures) or during an additional procedure. We present our experience of obtaining pericardial access during the index procedure in heparinized patients. METHODS AND RESULTS Patients undergoing catheter ablation of VT in whom pericardial access was performed after heparinization were included. Clinical and procedural data and complications were recorded. Electrocardiograms (ECGs) were analysed for published criteria suggesting an epicardial ablation target and compared with patients (matched for substrate) undergoing successful endocardial ablation. Seventeen patients (13 males, age 58 ± 16 years, 8 (47%) ischaemic) were evaluated. Pericardial access was achieved in 16 (94%), including 2 patients with prior epicardial ablation. The mean activated clotting time was 273 ± 36 s. No bleeding complications occurred. In three patients, inadvertent puncture of the right ventricle caused no adverse consequences. An epicardial ablation target was found in nine of which three (33%) had ECG criteria, suggesting an epicardial circuit. In comparison 5 of 17 patients undergoing successful endocardial ablation had at least one ECG criterion suggesting an epicardial ablation target. CONCLUSION Obtaining pericardial access for epicardial catheter ablation for VT appears to be safe in heparinized patients. Electrocardiogram criteria suggesting an epicardial ablation target lack the sensitivity and specificity accurately to predict which patients might need epicardial ablation. Performing pericardial access in heparinized patients therefore may reduce unnecessary punctures and reduce the number of additional procedures in some patients.

Ischemic Ventricular Tachycardia Presenting as a Narrow Complex Tachycardia

This report describes a patient presenting with a narrow complex tachycardia in the context of prior myocardial infarction and impaired ventricular function. Electrophysiological studies confirmed ventricular tachycardia and activation and entrainment mapping demonstrated a critical isthmus within an area of scar involving the His-Purkinje system accounting for the narrow QRS morphology. This very rare case shares some similarities with upper septal ventricular tachycardia seen in patients with structurally normal hearts, but to our knowledge has not been seen previously in patients with ischemic heart disease.

THE PREVALENCE OF LEFT ATRIAL APPENDAGE THROMBUS IN PATIENTS UNDERGOING CATHETER ABLATION FOR ATRIAL FIBRILLATION MAINTAINED ON WARFARIN

Introduction Reports of the prevalence of left atrial appendage (LAA) thrombus among patients undergoing catheter ablation for atrial fibrillation (AF) vary and may depend on the anticoagulation regime used prior to the procedure. Methods We undertook transoesophageal echocardiograms (TOE) in 586 patients (age 59.9±0.4 years old, mean±SE, 64.5% male) undergoing catheter ablation for AF who were anti-coagulated on warfarin (international normalised ratio 2–3) for at least 3 consecutive weeks prior to procedure and maintained on warfarin for the procedure itself. Results LAA thrombus was identified in 3 patients from 586 (0.5%) despite all 3 having therapeutic INRs (2.2, 2.2 and 3.3 respectively). None of the remaining patients had a peri-procedural stroke. The three patients with LAA thrombus had CHADS2 scores of ≥1 and CHA2DS2-VASc scores of ≥2. All three patients had impaired left ventricular systolic function (LVSF), and LAA emptying velocities of <40 cm/s (23, 29 and 31 cm/s). Patients with LAA emptying velocities <40 cm/s on TOE (n=111) had significantly (p<0.05) higher CHADS2 (0.9±0.1 vs 0.7±0.001) and CHA2DS2-VASc scores (1.7±0.1 vs 1.4±0.1), and larger LA diameter (4.95±0.09 vs 4.38±0.05 cm, OR for LA >4.6 cm: 2.4, 95% CI 2.13 to 5.41), and were more likely to have impaired LVSF (OR: 2.66, 95% CI 1.52 to 4.66) compared to those with higher velocities on multivariate analysis. Conclusions The prevalence of LAA thrombus using our anticoagulation regime is extremely low. Providing patients have been therapeutically anti-coagulated, pre-operative TOE need only be performed in patients with a CHADS2 score of ≥1/CHA2DS2-VASc score of ≥2 or when LA diameter is >4.6 cm. This criteria has the highest sensitivity (84%) for identifying LAA velocities of <40 cm/s as well as having a sensitivity of 100% for identifying thrombus and also would reduce the number of TOEs performed by 27.7%.

Chest pain and ST elevation

A 53 year old Vietnamese man developed chest pain at rest and dialled the emergency services. The ambulance service identified ST elevation on 12 lead electrocardiography (ECG) and according to local protocol brought him direct to our cardiac centre with a suspected ST elevation myocardial infarction. On arrival he reported a three hour history of central chest pain without radiation or associated symptoms. He was a current smoker but had no other risk factors for coronary artery disease. Examination was unremarkable and an ECG was performed on arrival. In lead V1 there was 2 mm of coved J point elevation, with an inverted T wave. In V2 there was 4 mm of J point elevation, with a saddle shaped ST segment and an upright T wave. In V3 the J point, ST segment, and T wave were within normal limits. He underwent immediate coronary angiography, which showed mild atheroma in the left anterior descending artery, but no obstructive lesions, and transthoracic echocardiography showed normal cardiac structure with good biventricular function. Overnight he developed a productive cough associated with a fever. Serial ECGs were recorded while he was febrile and showed 3 mm of coved J point elevation in lead V1 and 5 mm of coved J point elevation in V2, with associated T wave inversion. On further questioning he admitted to a history of well tolerated intermittent palpitations of up to an hour’s duration. His father had died suddenly and unexpectedly by falling from a bridge, but …