Ventricular fibrillation triggered by cavotricuspid isthmus radiofrequency ablation with a dual-energy lattice-tip catheter in a patient with an implantable cardioverter-defibrillator

POSTER PRESENTATIONS

Atrial tachyarrhythmias cause highly symptomatic conditions and have a negative impact on the patients’ quality of life (QoL). In the management of such patients, it is particularly important to consider not only objective indicators, but also the subjective well-being of patients and their everyday life. The patho-specific questionnaire for assessing the QoL is the ASTA symptom scale. The aim of the work was to conduct a patho-specific assessment of the QoL using the ASTA protocol after radiofrequency ablation (RFA) for atrial tachyarrhythmias on the example of performed cavo-tricuspid isthmus (CTI) RFA among patients with typical atrial flutter. Materials and methods. In total, 135 patients from the National Amosov Institute of Cardiovascular Surgery were asked to complete the ASTA questionnaire before CTI RFA and during two follow-up visits in the period from 2014 to 2021. To assess the patients’ QoL, a statistical analysis was performed in accordance with the 6th part of chapters 2 and 3. Results. When analyzing complaints, statistically significant changes were found in all aspects compared to the initial state (p < 0.05). The most noticeable changes were related to the anxiety level and heart failure manifestations, in particular, dyspnea on exertion and at rest, weakness and exhaustion (p < 0.0001). The least but also statistically significant changes were associated with comorbid pathologies. Analyzing the third chapter, positive statistically significant dynamics were observed in all characteristics during the control period. After RFA, the patients reported improvements in their QoL, decreased level of depression and restored physical activity (p < 0.0001). There was also a significant improvement in social life, as there were no more restrictions in spending time with relatives and friends (p < 0.0001). In addition, there was an improvement in the ability to concentrate and in the working capacity (p < 0.0001). Conclusions. Atrial tachyarrhythmias significantly affect the QoL of patients, including their emotional, physical state and social integration, worsening the daily lives of the study participants.

ORAL PRESENTATION

heart failure in Emery-Dreifuss muscular dystrophy can progress quickly unless the previously stable condition. The use of correct regimens of immunosuppression therapy provides good long-term results of the heart transplantation.

Sudden cardiac death (SCD) is a major public health problem in North America, responsible for approximately 400 000 deaths annually.1,2 Most episodes of SCD in ambulatory populations result from ventricular tachyarrhythmias,3 whereas bradyarrhythmias may be important in some populations, notably hospitalized patients with advanced heart failure4 (Figure 1). A prior article in this series by Zipes and Wellens2 provides a detailed review of the pathogenesis of SCD, its underlying causes, and treatment strategies. Figure 1. Mechanisms of SCD in ambulatory persons. Most SCDs result from ventricular fibrillation. VT, bradyarrhythmias, and other mechanisms account for the remainder. ### ICD Therapy The availability of a therapy that reliably terminates the vast majority of life-threatening tachyarrhythmic and bradyarrhythmic events has tremendous clinical appeal. The implantable cardioverter defibrillator (ICD) represents such a therapy. Despite its appeal, the ICD is imperfect. Currently, systems are costly, have a limited life expectancy, and are subject to complications in the long term.5,6 Furthermore, many patients at risk for SCD are at risk of dying from causes that the ICD would not alter. The impact of ICD shocks also merits consideration. Evidence links multiple shocks with myocardial injury7 and fibrosis,8 and sporadic shocks are associated with significant, independent reductions in quality of life. Compared with patients not having shocks, patients in the Antiarrhythmics Versus Implantable Defibrillators (AVID) trial who had ≥1 shocks in the initial year of follow-up had significant declines in self-perceived physical functioning and mental well-being, independent of ejection fraction (EF), social circumstances, and medication use. The reduction in quality of life associated with shocks was of a magnitude similar to clinically important adverse effects from amiodarone.9 Cost-efficacy is a vital issue in settings of limited or restricted health care resources6 and is particularly relevant as ICD use is expanded to …

Disorders of the cardiac muscle or cardiomyopathies are a broad, yet collectively common, group of conditions. Despite the heterogeneous etiologies, mode of death from these conditions is remarkably similar - progressive decline in cardiac function leading to intractable heart failure (HF) and sustained ventricular arrhythmias resulting in sudden cardiac death (SCD). Nearly 50% of patients die within 5 years of a HF diagnosis.1 Indeed, in the United States, HF alone is thought to cause 55,000 deaths per year2 and further contribute to 1 in 9 deaths overall.1 However, while advanced HF and the risk of SCD were once thought to be untreatable, technological advances has seen the emergence of device therapies as viable treatment options. Specifically, implantable cardioverter-defibrillator (ICD) therapy for treatment of ventricular arrhythmias, cardiac resynchronization therapy (CRT) for restoring cardiac synchrony and mechanical efficiency, and ventricular assist device (VAD) therapy to temporarily or permanently replace the function of the failing heart, have all emerged as highly efficacious therapies. The expanding use of device therapies, however, poses many challenges. First, while the indications for these devices are well summarized in clinical guidelines,3,4 considerable hurdles remain in ensuring eligible patients receive these therapies.5 By the same token, establishing the safety and effectiveness of these therapies in populations that are found in clinical practice, yet commonly excluded from trials, such as the elderly6 and uncommon forms of cardiomyopathies,7 is a high priority. Second, rapid dissemination of technologies frequently results in disparities in care. Indeed, age, gender, and racial disparities, in both receipt of these devices and outcomes following implantation, have been well documented. Whether these disparities have persisted, and the potential causative mechanisms underlying these disparities, however, are uncertain.8,9 Third, these devices are not without significant untoward effects; understanding …

Implantable Cardioverter Defibrillator

Although radiofrequency ablation of the cavotricuspid isthmus (CTI), responsible for sustaining atrial flutter, is a highly effective procedure, in extended patient observations following this procedure, more than 10% becomeunsuccessful. Therefore, this study was aimed at providing helpful information about the anatomy of the CTI in transthoracic echocardiography, which could aid better planning of CTI radiofrequency ablation in patients with typical atrial flutter. 56 patients with typical atrial flutter after radiofrequency ablation were evaluated at the end of a 24-month observation period. With substernal modified transthoracic echocardiographic (mTTE) evaluation, we identified four main anatomical obstacles impeding radiofrequency ablation: tricuspid annular plane systolic excursion, cavotricuspid isthmus length, cavotricuspid isthmus morphology, and the presence of a prominent Eustachian ridge/Eustachian valve. All intraprocedural radiofrequency ablation data was collected for analysis and correlated with anatomical data. Over a 24-month observation period, freedom from atrial flutter was 67.86%. The mean length of the isthmus was 30.34 ± 6.67 mm. The isthmus morphology in the 56 patients was categorised as flat (n = 27; 48.2%), concave (n = 10; 17.85%), or pouch (n = 19, 33.9%). A prominent Eustachian ridge was observed in 23 patients (41.1%). Lack of anatomical obstacles in mTTE evaluation resulted in 100% efficacy, while the presence of at least two obstacles significantly increased the risk of unsuccessful ablation with more than two (OR 12.31 p = 0.01). Generally, 8 mm electrodes were the most effective for non-difficult CTI, while 3.5 mm electrodes used with a 3D system had highest performance forcomplex CTI. Notably, ageing was the only factor that worsened the long-term outcome (OR 1.07 p = 0.044). Preoperative use of mTTE evaluation helps predict difficulty in cavotricuspid isthmus radiofrequency ablation, thus allowing better planning of the radiofrequency ablation strategy using the most accurate radiofrequency ablation electrode.

The “modern” era of the treatment of ventricular tachyarrhythmias with device-based therapy may have begun in 1899, when Prevost and Battelli noted, almost as an afterthought, that direct current shock could terminate ventricular fibrillation (VF) in dogs.1 Three decades later, pioneering work in the field of defibrillation concluded that the passage of electrical current across the heart can both initiate and terminate VF.2,3 Still, little attention was paid to this phenomenon, as evidenced by Paul Dudley White’s Heart Disease , which devoted less than half a page to VF and characterized the arrhythmia as “a condition of little importance so far as we know now.”4 In 1947, the thoracic surgeon Claude Beck saved the first human life by the successful use of cardiac defibrillation in a 14-year-old boy who developed VF during a thoracic surgical procedure and went on to achieve a full recovery.5 These early accomplishments provided the foundation for the landmark work of Mirowski and Mower that ultimately led to the development of the implantable cardioverter-defibrillator (ICD) and its introduction in humans in 1980.6 Pacing may prevent sudden cardiac death due to bradyarrhythmias and in certain circumstances such as torsade de pointes associated with congenital long-QT syndrome (LQTS) and pause-dependent ventricular tachycardia (VT). Although no controlled studies exist, retrospective analyses suggest that recurrent torsade de pointes in patients with LQTS may be prevented by continuous pacing.7 Early clinical data on small numbers of patients suggested that the combination of β-adrenergic blockade plus continuous pacing reduced the number of syncopal events and the anticipated rate of sudden death in high-risk LQTS patients.8 The beneficial effects of pacing may be limited to patients with LQT2 and LQT3, in which the transmural dispersion of repolarization worsens steeply during bradycardia.9 Genotype-phenotype correlation confirms that …

The implantable cardioverter-defibrillator (ICD) was devised to satisfy the unmet need for an effective, instantaneous therapy to prevent sudden cardiac death (SCD) due to ventricular fibrillation (VF) in at-risk, ambulatory patients. That therapy was a high-voltage electric shock delivered directly into the heart muscle. More than 3 decades later, shocks are still the defining operating characteristic of ICDs, and no other instantaneously effective therapy for VF exists. This elite status was clinched by large randomized clinical trials1,2 which demonstrated that ICDs improved mortality in patients with reduced left ventricular ejection fraction, regardless of pathogenesis or accompanying symptoms of heart failure (HF), by primary prevention of SCD due to ventricular tachyarrhythmia (VTA). Like bradycardia pacemakers for asystole, the ICD resides as a therapy genre of one, with no peer, and no competitor on the horizon. These sibling therapies for lethal heart rhythm disturbances will stand prominently among the greatest medical achievements of the 20th century. The ICD is a mature technology, and neither the technique nor the tools have changed much for several decades. Despite a certain evolutionary elegance of the operating system, the ICD is still a blunt instrument. Although it is true that some innovation has occurred, it is still a matter of a shock delivered by insulated metal conductors residing somewhere in direct proximity to the heart. No innovation beyond the fundamental of a timed shock for VF has proven to enhance mortality benefit. The basic design persists simply because no one can think of a suitable alternative and the self-satisfying aphorism that “shocks save lives.” Yet there is a growing intellectual dissatisfaction with the unintended consequences of this powerful, irreplaceable therapy. The stimulus for this self-inspection is an awareness of the very high morbidity risk overhead borne by the primary prevention patient, in particular, …

Sudden cardiac death (SCD) accounts for >300 000 deaths in the United States annually.1 Although the majority of these deaths occur in low-risk populations2 in which aggressive interventions are not practical, some higher-risk populations have been established in whom intervention with an implantable cardioverter-defibrillator (ICD) has been shown in randomized trials to reduce mortality.3–7 Additionally, there is a population of patients who may benefit from automatic emergency cardioversion-defibrillation but are not deemed appropriate candidates for ICD implantation at the time of presentation. This group is defined by 2 populations. The first subgroup comprises those who are at perceived risk but for whom there may be optimism for clinical improvement (eg, patients soon after revascularization or those with a recent diagnosis of myocardial infarction [MI] or cardiomyopathy). Alternatively stated, the optimal management of these patients at risk (or perceived risk) during the waiting period before an ICD is indicated remains unknown. The second subgroup includes those who have a clear indication for ICD but also have a contraindication to immediate ICD placement (eg, active infection or unknown prognosis). The wearable cardioverter-defibrillator (WCD) is a device designed for patients at risk of SCD who are not immediate candidates for ICD therapy. By providing automatic therapy, the WCD does not depend on a second person to defibrillate, as required with a manual or automated external defibrillator (AED). Unlike the ICD (including both transvenous and subcutaneous devices), the WCD requires no surgical operation, can be provided for a short period of time, is temporary, and is easily removed. These characteristics of the WCD, along with safety and efficacy data presented to the US Food and Drug Administration (FDA), resulted in approval in the United States in 2002.8 Because of the increasing use of the WCD and uncertainty of indications …

Sex differences have the potential to impact diagnostic and therapeutic interventions in a wide variety of medical conditions, and cardiac arrhythmias are no exception.1 Studies evaluating pathophysiology, disease course, and therapeutic options for cardiac arrhythmias have been performed predominantly in male patients. However, catheter and device-based therapies coupled with landmark clinical trials have contributed to an improved understanding of this important aspect. The objective of this review is to present the current state of knowledge on sex differences in cardiac arrhythmias with a focus on clinical management, while highlighting gaps in knowledge that would benefit from future investigation. ### Atrial Fibrillation and Atrial Flutter #### Disease Burden Atrial fibrillation (AF) and atrial flutter (AFL) are the most commonly encountered tachyarrhythmias in clinical practice, with significant implications for public health and healthcare costs. Stroke, hospitalization, and loss of productivity are the major consequences of AF.2 The incidence of AF (per 1000 person-years) is reported to be between 1.6 and 2.7 in women and between 3.8 and 4.7 in men.2 The age-adjusted incidence and prevalence of AF is lower in women compared with that in men, and accordingly, the lifetime risk of AF from the Framingham Heart Study at 40 years of age was higher in men (26.0% for men versus 23.0% for women).3 Another analysis from the Framingham Heart Study demonstrated no significant sex differences in the risk of developing AFL.4 The prevalence of AF continues to rise among both men and women. In a study investigating the global burden of disease from 1980 to 2010, there was not only an increase in overall burden, incidence, and prevalence of AF, but most importantly an increase in AF-associated mortality in both men and women (Figure 1).5 The age-adjusted mortality for women was consistently higher compared with that for men from 1990 to 2010 (Figure …

The first successful implant of an automated internal defibrillation system was described in 19801. Since then the number of indications for implantable cardioverter defibrillator (ICD) therapy has grown and the number of implants has risen rapidly2. As a result, growing numbers of patients with ICD's are presenting for surgery, potentially giving rise to uncertainty about device management, especially in emergency settings. We have collated manufacturers' recommendations, professional guidance and the relevant literature to provide support for surgical decision-making when faced with a patient with an ICD (figure). Electromagnetic interference (EMI) is the main safety concern that arises when patients with ICD's undergo surgery. Theoretically EMI from diathermy devices can interfere with ICD sensing which may result in spurious detection of a ventricular arrhythmia (oversensing) and delivery of a defibrillator shock. Other potential risks to the ICD include reprogramming, temporary inhibition of pacing functions or irreversible damage to the internal circuitry3. Two types of surgical diathermy are in common use: monopolar and bipolar of which the former is more widely used in practice. Monopolar electrical current enters the patient via an active electrode. The current travels through the patient and returns to the generator via a dispersing ground electrode. The active electrode usually discharges current through a surgical instrument. If the diathermy unit is activated prior to contact between the active electrode and the surgical instrument, the electric current may arc through the air toward the instrument and demodulate the electronic signal. Such a signal may be over sensed by the ICD resulting in an inappropriate discharge. Bipolar diathermy involves the flow of current between two tips of a bipolar forceps. Current passes from the active electrode at one tip through the patient (but only at the diathermy site) to the dispersive electrode at the other forceps tip. Therefore the theoretical risk of EMI associated with bipolar is substantially less than with monopolar diathermy. Diathermy is not the only potential medical source of EMI; others include magnetic resonance scanners, radiofrequency ablation, lithotripsy, radiation therapy and transcutaneous electronic nerve stimulation (TENS) units3. Non-medical sources include anti-theft surveillance devices, slot machines, electric razors, showering and even household items such as washing machines. Interference with ICD functions has been described with all of these aforementioned technologies but studies that have addressed specifically the interaction between surgical diathermy and ICD's found no evidence of oversensing, reprogramming or device damage. This is a limited evidence base, the largest series involving 45 patients undergoing a variety of elective surgical and interventional procedures4 and no studies have been performed in the emergency setting. Nonetheless it may be concluded that as a result of progressive refinements in ICD design (titanium shielding, signal filtering, interference rejection circuits and noise rejection functions) the risk of a harmful interaction between surgical diathermy and an ICD is very small. Chest X-Ray appearances of a dual chamber ICD. Green arrow: battery and pulse generator. Red arrow: right atrial appendage lead (bradycardia sensing and pacing). White arrow: right ventricular lead (bradycardia sensing and pacing, anti-tachycardia pacing and defibrillation). When a patient with an ICD comes for elective surgery, pre-procedural planning can be undertaken to minimise the risk to the patient, operators and device3,5–7 (Table). Reprogramming to monitor mode involves deactivation of the ICD's ability to sense and treat ventricular tachycardia and ventricular fibrillation. It allows electrical signals to be recorded throughout the procedure but no action will be taken should they be interpreted as a ventricular arrhythmia. Clearly under such circumstances arrhythmias should be treated as they would in a patient who does not have an ICD. Arrhythmic precipitants (hypoxia, hypotension, metabolic derangements) should be corrected and standard cardiopulmonary resuscitation measures should be implemented in the event of cardiac arrest. If external defibrillation is required the risk of damage to the ICD and myocardial injury will be minimized if an antero-posterior (A-P) pad position is adopted. If this is not possible, the pads should be placed at least 10–15 cm from the ICD. Table Perioperative ICD management recommendations7 If a patient presents with a life-threatening surgical emergency7, preoperative ICD interrogation and reprogramming may not be available. This should not be interpreted as a contraindication to emergency surgery. Rather, the diathermy precautions outlined in the Table should be followed. As previously mentioned the risk of a harmful interaction between surgical diathermy and ICD's appears to be largely theoretical and a much greater risk is likely to be caused by delay or deferral of potentially life-saving surgery in patients with surgical emergencies. Despite the exponential increase in ICD implants, there is limited expert guidance about the best perioperative management of patients with ICD's, especially in emergency settings. However the available published information suggests that surgical diathermy poses a substantially smaller hazard than many other medical and indeed non-medical electromagnetic sources.

Do elderly patients benefit from implantable-cardioverter defibrillators?

Rhetorical Strategies Used in the Reporting of Implantable Defibrillator Primary Prevention Trials