Catheter ablation in highly symptomatic Brugada patients: a Dutch case series.

AIMS: In the past few years, promising results were described in targeting the arrhythmogenic substrate of the epicardial right ventricular outflow tract (RVOT) region in patients with Brugada syndrome (BrS). In this report, we describe our experience with endo- and epicardial substrate mapping and ablation in a series of highly symptomatic BrS patients. METHODS: This case series consists of seven patients with clinical BrS diagnosis who underwent catheter ablation in two Dutch hospitals (Isala hospital Zwolle; and Amsterdam University Medical Centre, location AMC, Amsterdam) and Hamad Heart Hospital in Qatar between 2013 and 2017. All patients had an ICD and recurrent ventricular arrhythmia (VA) episodes. All patients underwent endo-and epicardial mapping of the RVOT region. Elimination of all abnormal potentials and disappearance of BrS ECG pattern during the ablation procedure was the aimed endpoint. RESULTS: The study group consisted of seven patients with mean age 45.6 ± 16.9 years. Five patients had SCN5A mutations. One patient was excluded from analysis, since ablation could not be performed due to a very large low-voltage area and was later diagnosed with arrhythmogenic right ventricular cardiomyopathy, associated with an SCN5A mutation. One patient underwent both endo- and epicardial ablation to eliminate VA. During a mean follow-up of 3.6 ± 1.5 years, 5/6 patients remained VA free with two patients continuing quinidine. CONCLUSION: In patients with BrS and drug-refractory VA, ablation of the arrhythmogenic substrate in the RVOT region was associated with excellent long-term VA-free survival. The majority of these highly symptomatic BrS patients had an SCN5A mutation and also low-voltage areas epicardially.

Effective contact and outcome after pulmonary vein isolation in novel circular multi-electrode atrial fibrillation ablation.

INTRODUCTION: Pulmonary vein (PV) reconnection is frequently the cause of recurrence of atrial fibrillation (AF) after ablation. The second-generation gold multi-electrode ablation (Gold-MEA) catheter has a new design possibly resulting in improved lesion formation compared with its predecessor. We aimed to determine the association between effective radiofrequency applications with the Gold-MEA catheter and outcome after AF ablation. METHODS: 50 consecutive patients with paroxysmal AF underwent Gold-MEA (PVAC GOLDTM, Medtronic Inc.) ablation. The Gold-MEA catheter was navigated to the PV ostium by fluoroscopy. Duty-cycled radiofrequency ablations were performed at all PV ostia. Lesions were considered transmural when electrode temperature was >50 °C and power >3 W for >30 seconds. After the ablation procedure, patients visited the outpatient clinic at 3­month intervals including 24-hour Holter ECGs. RESULTS: Mean age was 56 years. All PVs were acutely isolated with the Gold-MEA catheter. Procedure time was 111 ± 22 minutes, ablation time was 24 ± 6.7 minutes and fluoroscopy time was 20 ± 8.1 minutes. No procedure-related complications were observed. One year after ablation, 60 % of patients were still free of arrhythmia recurrences after a single PV isolation attempt. The number of transmural lesions was associated with arrhythmia-free survival: 25.0 % in <72 transmural lesions, 64.3 % in 72-108 transmural lesions and 71.4 % in >108 transmural lesions (p = 0.029). CONCLUSION: PV isolation can be performed successfully with the Gold-MEA catheter, with a favourable safety profile. Transmurality of lesions was associated with ablation success and may improve AF ablation success.

Characteristics of cardiac device infections in the Isala Hospital; a large volume tertiary care cardiology centre.

AIMS: To determine the frequency, characteristics and risk factors of cardiac device infections in the Isala Hospital. METHODS: We retrospectively studied all patients who underwent cardiac device procedures performed in the cardiac catheterisation lab and the operating room from 2010 to 2012. All patients who developed a cardiac device infection were reviewed for its characteristics. RESULTS: 31/2026 patients developed a cardiac device infection (1.5 %). One (3.2 %) patient died within 30 days of hospitalisation. Device infection rates for procedures in the catheterisation lab and operating room were similar (p = 0.60). Positive cultures were present in 27/31 (87 %) cases. These consisted predominantly of micro-organisms that are part of the skin flora (84 %). The mean time between device procedure and infection was 14 ± 21 months (range 0-79). Cardiac device infection was significantly associated with device revision, (65 % were revisions in patients with device infection vs. 30 % revisions in patients without device infection, p = 0.011) and placement of a left ventricular lead in pacemaker implantations (59 % of patients with vs. 51 % of patients without device infection, p < 0.001). CONCLUSION: The frequency of cardiac device infection was 1.5 % with a mortality of 3.2 % within 30 days, which is lower compared with other registries. Cardiac device infections were associated with device revisions and placement of left ventricular leads in pacemaker implantations.

Association of apical rocking with super-response to cardiac resynchronisation therapy.

BACKGROUND: Super-responders to cardiac resynchronisation therapy (CRT) show an exceptional improvement in left ventricular ejection fraction (LVEF). Previous studies showed that apical rocking was independently associated with echocardiographic response to CRT. However, little is known about the association between apical rocking and super-response to CRT. OBJECTIVES: To determine the independent association of LV apical rocking with super-response to CRT in a large cohort. METHODS: A cohort of 297 consecutive heart failure patients treated with primary indication for CRT-D were included in an observational registry. Apical rocking was defined as motion of the left ventricular (LV) apical myocardium perpendicular to the LV long axis. 'Super-response' was defined by the top quartile of LVEF response based on change from baseline to follow-up echocardiogram. Best-subset regression analysis identified predictors of LVEF super-response to CRT. RESULTS: Apical rocking was present in 45 % of patients. Super-responders had an absolute mean LVEF increase of 27 % (LVEF 22.0 % ± 5.7 at baseline and 49.0 % ± 7.5 at follow-up). Apical rocking was significantly more common in super-responders compared with non-super-responders (76 and 34 %, P < 0.001). In univariate analysis, female gender (OR 2.39, 95 % CI 1.38-4.11), lower LVEF at baseline (OR 0.91 95 % CI 0.87-0.95), non-ischaemic aetiology (OR 4.15, 95 % CI 2.33-7.39) and apical rocking (OR 6.19, 95 % CI 3.40-11.25) were associated with super-response. In multivariate analysis, apical rocking was still strongly associated with super-response (OR 5.82, 95 % CI 2.68-12.61). Super-responders showed an excellent clinical prognosis with a very low incidence of heart failure admission, cardiac mortality and appropriate ICD therapy. CONCLUSION: Apical rocking is independently associated with super-response to CRT.

First Dutch experience with the endoscopic laser balloon ablation system for the treatment of atrial fibrillation.

INTRODUCTION: The endoscopic laser balloon ablation system (EAS) is a relatively novel technique to perform pulmonary vein isolation (PVI) in the treatment of atrial fibrillation (AF). The present study aimed to report the results of the first 50 patients treated in the Netherlands with the EAS in terms of procedural characteristics and AF-free survival. METHODS: Fifty patients successfully underwent EAS PVI. Median follow-up was 17 months. Mean age was 56 years, 82 % had paroxysmal AF. RESULTS: 99 % of the pulmonary veins were successfully isolated with the EAS. Mean procedure time was 171 min and mean fluoroscopy time was 36 min. One procedure was complicated by a temporary phrenic nerve palsy (2 %). During follow-up, 58 % of patients remained free of AF without the use of antiarrhythmic drugs. CONCLUSION: PVI with EAS is associated with a low risk of complications and a medium-term AF-free survival comparable with other PVI techniques.

Incidence of lead dislodgement, malfunction and perforation during the first year following device implantation.

BACKGROUND: The number of cardiac rhythm device implantations has been growing fast due to expanding indications and ageing of the population. Complications of implantation were rare in the trials. However, these involved small numbers and selected patients. Prospective real-life data are necessary to assess cardiac device implantation procedure-related risks. OBJECTIVE: To determine the incidence and predictors of lead-related re-intervention in a Dutch high-volume teaching hospital. METHODS: Data from all patients who underwent cardiac rhythm device implantation between January 2010 and December 2011 were collected in a prospective registry. At least 1 year of follow-up regarding re-intervention was available for all patients. Lead-related reasons for re-intervention were categorised into lead dislodgement, malfunctioning or perforation. RESULTS: One thousand nine hundred twenty-nine devices including 3909 leads were implanted. In 595 patients (30.8 %) a CRT-D/P was implanted. Lead-related re-intervention was necessary in 86 (4.4 %) patients; it was more common in younger and male patients, and due to either lead dislodgement (66 %), malfunctioning (20 %) or perforation (18 %). Coronary sinus lead dislodgement or malfunctioning was 1.4 %. Right atrial dislodgement (1.9 %, p < 0.001) or ICD lead dislodgement (1.8 %, p = 0.002) was more common than right ventricular dislodgement (0.3 %). The incidence of lead malfunctioning was higher (0.8 %) in ICD leads. An apical position of the right ventricular lead and lateral wall position of the right atrial lead were related to cardiac perforation. CONCLUSIONS: The incidence of lead-related re-intervention was comparable with the literature. The majority of re-interventions were due to lead dislodgements, particularly with right atrial and ICD leads. Re-intervention due to coronary sinus lead dislodgement was rare.

Clinical cardiology consultation at non-cardiology departments: stepchild of patient care?

BACKGROUND: Although patient care in cardiology departments may be of high quality, patients with cardiac disease in other departments tend to receive less attention from cardiologists. Driven by the shorter duration of admission nowadays and the fact that consultations are often performed in between the daily work schedules, the amount of cardiac disease as well as the impact on the daily workload can be underestimated. We determined characteristics, prevalence of cardiac disease and in-hospital mortality of patients in whom cardiology consultation was requested. METHOD: In this prospective, observational study, individual data of all consecutive patients admitted to non-cardiology departments in whom cardiology consultation was requested were registered. RESULTS: During the study period, 264 patients were included. Mean age was 70 years. Most patients were admitted to the internal medicine ward (37 %), followed by the surgical ward (30 %). The most common reasons for cardiology consultation were: suspected heart failure (20 %), suspected infective endocarditis (15 %), suspected rhythm abnormalities (14 %) and suspected acute coronary syndrome (13 %). In 29 % of all consultations a cardiac diagnosis was found. Hospital mortality was 9.0 %. CONCLUSION: Patients who are admitted to a non-cardiology department and who need cardiology consultation are particularly elderly people with a high prevalence of cardiac disease and high in-hospital mortality. For these reasons cardiology consultation is an important part of clinical cardiology deserving a structured approach.

Sex-Based Differences in Cardiac Arrhythmias, ICD Utilisation and Cardiac Resynchronisation Therapy.

Many important differences in the presentation and clinical course of cardiac arrhythmias are present between men and women that should be accounted for in clinical practice. In this paper, we review published data on gender differences in cardiac excitable properties, supraventricular tachycardias, ventricular tachycardias, sudden cardiac death, and the utilisation of implantable defibrillators and cardiac resynchronisation therapy. Women have a higher heart rate at rest, and a longer QT interval than men. They further have a narrower QRS complex and lower QRS voltages on the 12-lead ECG with more often non-specific repolarisation abnormalities at rest. Supraventricular tachycardias, such as AV nodal reentrant tachycardia, are twice as frequent in women compared with men. Atrial fibrillation, however, has a 1.5-fold higher prevalence in men. The triggers for idiopathic right ventricular outflow tract tachycardia (VT) initiation are gender specific, i.e. hormonal changes play an important role in the occurrence of these VTs in women. There are clear-cut gender differences in acquired and congenital LQTS. Brugada syndrome affects men more commonly and severely than women. Sudden cardiac death is less prevalent in women at all ages and occurs 10 years later in women than in men. This may be related to the later onset of clinically manifest coronary heart disease in women. Among patients who receive ICDs and CRT devices, women appear to be under-represented, while they may benefit even more from these novel therapies.

Characteristics of Sprint Fidelis lead failure.

Background. The Medtronic Sprint Fidelis ICD lead is prone to failure and the rate of failure seems to be increasing. The aim of this study was to investigate the rate of Sprint Fidelis lead failure, the characteristics, the mode of presentation and possible predictors of lead failure.Methods and Results. The rate, characteristics and presentation of Sprint Fidelis lead failure was assessed in this single-centre survey. 619 Sprint Fidelis ICD leads were implanted at our centre between December 2004 and August 2007. The mean follow-up was 32+/-10 (range 22-60) months; 35 patients (5.7%) required a lead re-implantation because of failure of the pace-sense conductor. Mean duration of lead survival was 23+/-12 (2-46) months and the rate of failure did not stabilise during follow-up. The mode of presentation was inappropriate shocks in 16 patients (45.7%), alarm alert in 12 patients (34.3%), and detection at routine follow-up in seven patients (20%). In 31 patients (89%), interrogation data revealed a sudden rise in impedance and/or frequent short VV intervals prior to lead failure and in five patients an isolated decrease of R wave (<2.5 mV). The interrogation data were not different from patients with shocks compared with patients without shocks. The interrogation data at routine follow-up in the first three months after implant were normal and stable.Conclusion. The rate of Sprint Fidelis lead failure reaches 5.7% at a mean follow-up duration of 32 months. The rate of failure does not seem to stabilise. Routine follow-up can not predict lead failure or prevent inappropriate shocks. (Neth Heart J 2010;18:12-7.).

Electrical storms in Brugada syndrome successfully treated with isoproterenol infusion and quinidine orally.

Brugada syndrome is an inherited cardiac disease and is associated with a peculiar pattern on the electrocardiogram and an increased risk of sudden death. Electrical storm is a malignant but rare phenomenon in symptomatic patients with Brugada syndrome. We describe a patient who presented with repetitive ICD discharges during two episodes of recurrent VF. After the initiation of isoproterenol infusion and oral quinidine, the ventricular tachyarrhythmias were successfully suppressed. (Neth Heart J 2007;15:151-4.).

Cardioverter defibrillator implantation in a patient with absent right superior vena cava.

Left-sided superior vena cava (LSVC) is the most common venous thoracic anomaly. Absence of the right superior vena cava (RSVC) on the other hand is very rare. We describe a patient with this abnormal venous system, who was admitted to our centre for an implantation of a cardioverter defibrillator (ICD).

Radiofrequency modified maze in patients with atrial fibrillation undergoing concomitant cardiac surgery.

OBJECTIVE: In the majority of patients with chronic atrial fibrillation the arrhythmia will persist after correction of the underlying structural abnormality. The maze procedure is an effective surgical method to eliminate atrial fibrillation and to restore atrial contractility. METHODS: In this study we used radiofrequency energy to create lines of conduction block in both atria during cardiac surgery as a modification of the maze III procedure. One hundred twenty-two patients with atrial fibrillation for at least 1 year and structural heart disease underwent open heart operation and a radiofrequency modified maze procedure. RESULTS: In 108 (89%) of 122 patients mitral valve surgery was performed, and in this group 86 patients (80%) underwent 121 concomitant procedures. Fourteen patients (11%) underwent cardiac surgery not involving the mitral valve. The additional crossclamp time required for the left atrial part of the radiofrequency modified maze procedure was 14 +/- 3 minutes. The in-hospital mortality rate was 4.1%. The overall 39-month survival was 90%, and freedom of atrial flutter or atrial fibrillation was 78.5% +/- 5.1%. Eighty-nine survivors with sinus, atrial rhythm, or atrioventricular sequential pacemaker had Doppler echocardiography, and right atrial transport function was documented in 83% and left atrial transport function in 77% of patients. CONCLUSION: We concluded that the radiofrequency modified maze procedure as an adjunctive procedure is safe, time-sparing, and effective in eliminating atrial fibrillation and restoring atrial transport function.

The radiofrequency modified maze procedure. A less invasive surgical approach to atrial fibrillation during open-heart surgery.

OBJECTIVE: Patients with mitral valve disease and suffering of atrial fibrillation of more than 1 year's duration have a low probability of remaining in sinus rhythm after valve surgery alone. Intraoperative radiofrequency ablation was used as an alternative to simplify the surgical maze procedure. METHODS: Seventy-two patients with mitral valve disease, aged 63+/-11 years ranging from 31 to 80 years, underwent valve surgery and radiofrequency energy applied endocardially, based on the maze III procedure to eliminate the arrhythmia. The right-sided maze was performed on the beating heart and the left-sided maze during aorta cross-clamping. RESULTS: Surgical procedures included mitral valve repair (n=38) or replacement (n=34) and in addition tricuspid valve repair (n=42), closure of an atrial septal defect (n=2) and correction of cor triatriatum (n=1). The left-sided maze needed 14+/-3 min extra ischemic time. There were two in-hospital deaths (2.7%) and three patients (4.2%) died during follow-up of 20+/-15 months. Among 67 surviving patients, 51 patients (76%) were in sinus rhythm, two patients (3%) had an atrial rhythm and eight patients (12%) had persistent atrial fibrillation or atrial flutter. Four patients had a pacemaker implanted, in one patient because of sinus node dysfunction. Doppler echocardiography in 64 patients demonstrated right atrial contractility in 89% and left atrial transport in 91% of patients. CONCLUSIONS: Intraoperative radiofrequency ablation of atrial fibrillation is an effective and less invasive alternative for the original maze procedure to eliminate atrial fibrillation.

Multisite atrial pacing: an option for atrial fibrillation prevention? Preliminary results of the Dutch Dual-site Right Atrial Pacing for Prevention of Atrial Fibrillation study.

Multisite pacing is a novel concept for the prevention of recurrent drug-refractory atrial fibrillation (AF). Two different pacing methods have been described, biatrial pacing and dual-site right atrial stimulation. The use of multisite pacing as preventive therapy for recurrences of atrial fibrillation is still under investigation. We conducted a prospective, randomized, crossover study in patients with recurrent drug-refractory AF without or with minimal structural heart disease. After implantation of a DDD pacemaker, patients were randomized to either dual-site pacing first (Group I) or single-site (high right atrium) pacing first (Group II) and, after 6 months of treatment, the device was reprogrammed to the other pacing mode. Preliminary results of 13 patients in each group are presented. Clinical characteristics of patients in both groups with respect to age, sex, left atrial dimension, left ventricular function, and New York Heart Association (NYHA) functional class were comparable. Pacing therapy was combined with antiarrhythmic drug treatment. After completion of the study protocol, the arrhythmia-free interval was not remarkably different in either group. However, the endpoint free interval (i.e., the need for electrical cardioversion because of recurrent AF lasting >24 hours, was less during dual-site pacing in Group II. Within 6 months, 43 patients enrolled in this study will have completed the protocol.

Surgical treatment of atrial fibrillation.

Surgical therapy has been applied in the treatment of atrial fibrillation for almost two decades. At present, the most commonly used approach is the maze operation developed by Cox. In this operation, atrial fibrillation is prevented by critically located incisional lines. Currently, these lines also are drawn during operation using cryoablation or radiofrequency current. To document the value of the maze operation, randomized studies, not only on arrhythmia prevention but also on atrial transport function and thromboembolic complications, should be performed.