Drug-Induced Atrial Fibrillation / Atrial Flutter

Drug-induced atrial fibrillation / flutter (DIAF) is a serious and potentially life-threatening complication of pharmacotherapy. Purpose of the work: systematization and analysis of scientific literature data on drugs, the use of which can cause the development of DIAF, as well as on epidemiology, pathophysiological mechanisms, risk factors, clinical picture, diagnosis and differential diagnosis, treatment and prevention of DIAF. Analysis of the literature has shown that many groups of drugs can cause the development of DIAF, with a greater frequency while taking anticancer drugs, drugs for the treatment of the cardiovascular, bronchopulmonary and central nervous systems. The mechanisms and main risk factors for the development of DIAF have not been finally established and are known only for certain drugs, therefore, this section requires further study. The main symptoms of DIAF are due to the severity of tachycardia and their influence on the parameters of central hemodynamics. For diagnosis, it is necessary to conduct an electrocardiogram (ECG) and Holter monitoring of an ECG and echocardiography. Differential diagnosis should be made with AF, which may be caused by other causes, as well as other rhythm and conduction disturbances. Successful treatment of DIAF is based on the principle of rapid recognition and immediate discontinuation of drugs (if possible), the use of which potentially caused the development of adverse drug reactions (ADR). The choice of management strategy: heart rate control or rhythm control, as well as the method of achievement (medication or non-medication), depends on the specific clinical situation. For the prevention of DIAF, it is necessary to instruct patients about possible symptoms and recommend self-monitoring of the pulse. It is important for practitioners to be wary of the risk of DIAF due to the variety of drugs that can potentially cause this ADR.

LONG-TERM AMBULATORY ECG MONITORING AN ESSENTIAL DIAGNOSTIC TOOL FOR CURRENT TIMES

Ambulatory ECG (AECG) monitoring with diary correlation of symptoms has been proven to provide significant diagnostic, therapeutic and prognostic benefit with an arrhythmic cause of symptoms. Arrhythmias can range from premature atrial and ventricular complexes (APCs/ PVCs usually benign), to Atrial and Ventricular Fibrillation which causes significant morbidity and mortality. Symptoms such as palpitations, shortness of breath, chest pain and syncope are common during arrhythmias and their frequency determines the choice of investigation needed to diagnose the arrythmia. Arrhythmias can be a manifestation of many cardiac and non-cardiac diseases. These also include congenital diseases and are often missed due to inadequate monitoring. Since most arrhythmias are intermittent they are more likely to be detected during extended ECG monitoring. Other uses of ambulatory ECG devices include ST segment analysis, heart rate variability, signal averaged ECGs, diurnal QT and QTc analysis (including patients with long QT) (1) obstructive sleep apnea and vectorcardiography (2). These factors have been shown to have relation to significant cardiovascular diseases aiding the diagnosis of various arrhythmias. Syncope although mostly benign, could potentially be a consequence of a life-threatening arrhythmia in up to 20% patients(3). Nonetheless syncope poses a significant cause of disturbance in a patients’ life and definitive diagnosis is necessary to ensure patients well-being. ESC Guidelines on Syncope (2018) recommend further testing with AECG via Holter monitoring, wearable patch recorder, external and internal loop recorders etc. depending on the frequency after initial examination is negative for a definite cause. Atrial Fibrillation (AF) increases risk of stroke more than five times. Atrial Fibrillation diagnosed after stroke is an important hallmark of recurrent stroke risk. (7) Many studies have demonstrated post stroke AECG increases the chances of detecting AF (15% vs 5%) when compared to standard monitoring. An increase incidence in atrial arrythmias (atrial high rate episodes AHRE) has been seen in patients with Permanent Pacemakers which should be documented by AECG to be treated accordingly.(4). Uses can be prognostic if rate was to be monitored in AF to assess efficacy of rate control treatment and offer adequate anticoagulation according to the 2020 ESC atrial fibrillation guidelines. (8) Some limitations of twenty-four hours Holter monitoring have recently been overcome by improvements in hardware and software technology including adhesive patches and wireless telemetry. Newer adhesive patches are softer, waterproof and electrode free monitors which offer unprecedented mobility and ease of carrying out daily routine by the patient. They operate as either recorders or wireless streaming devices (5). These devices were safe and effective during the pandemic even when delivered home through mail to critically ill patients.(6) The advent of smart phones has added endless potential for recording through wireless Bluetooth transmission. Smart devices like the OMSHIRTtm have the added advantage of being comfortable to wear. Newer devices for example Cardiostat has been shown to offer equal quality tracings when compared to standard Holter monitoring, often up to the 99% sensitivity and specificity through better designed R wave (QRS) detection algorithms(7) (8)Studies have shown these newer devices to be easily operable and can even be mailed to patients homes for self-attachment with an equal efficacy to hospital applied machine (6). Many studies have shown a preference over intra cardiac monitors (ICM) due to these above mentioned advantages (9). The effectiveness of even longer recordings through Implantable Loop Recorder has also been satisfactory when following patients after Ablation therapy leading to practice updating guideline changes in rhythm management(10). A recent review article summarized that although physicians in the US had knowledge of how and when to offer monitoring devices based on the frequency of symptoms, they were often seen prescribing Holter monitoring due to familiarity. Data also showed that in case the initial investigation was inconclusive, the physician would still repeat the same investigation(3). In a country like Pakistan where there are limited resources, diagnosis and management of arrythmias still has a long way to go. This article sheds light on the need of utilizing the recommended available devices.

Clinical and functional characteristics of children with ventricular arrhythmias depending on the ectopic focus localization

Aim. To determine the prevalence of ventricular arrhythmias (VA) among children with cardiac arrhythmias and to assess the clinical, functional, and electrophysiological characteristics of VA, depending on the localization of the ectopic focus.Methods. The study included 260 children, 153 (58,8%) boys, the mean age of patients was 13.4±3.1years. Based on clinical and anamnestic data, ECG, Holter monitoring, echocardiography, dosed exercise test, invasive electrophysiological study (EPS), radiofrequency ablation (RFA) a comparative assessment of the clinical and functional features of the most frequently diagnosed localizations of the ectopic focus in children with VA was carried out according to the data of invasive EPS, RFA.Results. According to invasive EPI, the most frequent localization of VA in children is the right ventricle outflow tract (RVOT) - 144 (55%), less often - the Valsalva sinuses - 52 (20%) and the RV free wall - 47 (18%). In most cases (255 children, 98%) there was a focal arrhythmia (trigger activity). The localization of ectopia in the RV free wall is characterized by the predominance of single ventricular premature beats (VPB) or in combination with a paired VPB (78,7%) and polymorphism of ventricular complexes (30%). The peculiarity of ventricular tachycardia in this localization is its stable character (17,0%) and low heart rate in volleys (idioventricular rhythm) (12,8%). When the focus was localized in the RVOT, as well as when it was localized in the RV free wall, single VPB or in combination with paired VPB prevailed (84,7%), but polymorphism of ventricular complexes was less often observed (10,4%). Differences in myocardial contractility at the sinus rhythm in right ventricular arrhythmias were revealed. Thus, the ejection fraction at the localization of the lesion in the RV free wall was significantly lower than in the RVOT (63.4±5.5% and 65.8±5.9%, respectively; p<0.01). Hemodynamic significance is characteristic for RV arrhythmias (21.3% and 16.0% of patients) and was practically not observed at the left-sided localization of the arrhythmogenic focus (3.8%; p<0.01). VA in patients without structural heart disease, regardless of the localization of the arrhythmic focus in children, is asymptomatic and is detected, in most cases, within the framework of clinical examination 206 patients, 79.2%. The prevalence of syncope in children with idiopathic VA is 15.8% (41 patients), and in most cases, they are of vaso-vagal origin. In most children (178, 70%), idiopathic VA is dependent on the level of parasympathetic influences on the heart, disappearing or significantly decreasing during exercise, which is revealed during the stress test confirming the high role of autonomic influences on the regulation of heterotopic rhythm in children with VA.Conclusion. VA is a common arrhythmia in children. Depending on the localization of the arrhythmogenic focus, characteristic features of the structure and density of the heart, as well as differences in the contractile function of the myocardium on the sinus rhythm and on the ectopic complex were revealed.

Samples of standard operating procedures performed by mid-level workers in departments and rooms of functional diagnostics

As an example standard operating procedures performed by nurses in functional diagnostics departments are given. Methods of registration of electrocardiogram, electroencephalogram, spirogram, setting of recorders for Holter monitoring and blood pressure monitoring are considered.

Successful ablation of bifocal PVCs from both left bundle branches triggering polymorphic VT in LQTS 2—A case report

Background A 19-year-old woman with an established diagnosis of long QT syndrome (LQTS) 2 and underlying KCNH2-mutation was referred to our centre for recurrent polymorphic ventricular tachycardia (VT) and ventricular fibrillation (VF) refractory to medical therapy and bilateral thoracic sympathectomy. Case summary Holter monitoring revealed a relevant PVC burden of two different morphologies. One PVC was originating from the left anterior fascicle, the other from the left posterior fascicle. Radiofrequency ablation resulted in complete suppression of both spontaneous PVC morphologies with a favourable clinical course over the next 2 years. Discussion This case presents two interesting insights: Firstly, the consistent bigeminal pattern of the torsade de pointes triggering PVC. These were retrieved from the device interrogation and correlated with the pattern that was seen at the time of the procedure. Secondly, PVC morphologies suggested an origin from both the left ventricular (posterior and anterior) fascicles, which has not been described so far. This was confirmed by the preceding Purkinje potentials seen at the successful ablation sites in sinus rhythm and during PVC. Ablation of triggering PVCs causing recurrent VT/VF in LQT 2 syndrome is feasible and effective over a mid-term Follow-up.

Initial Experience with Fractionation Mapping in the Identification of Vagal Ganglionated Plexus During Cardioneuroablation

This is a series case report of five symptomatic patients presented with diagnosis of sinus bradycardia, first and second degrees atrioventricular (AV) blocks, that were referred to pacemaker implantation. During the screening, a functional cause for the bradycardia and AV blocks were documented by treadmill stress test, 24-hour Holter monitoring and atropine test. After the confirmation of the diagnosis, patients were submitted to cardioneuroablation on an anatomical basis supported by a tridimensional electroanatomical fractionation mapping software. The technique and the acute and short-term results of the cardioneuroablation are described.

Identifying patients with atrial fibrillation recurrences after two pulmonary vein isolation procedures

IntroductionPulmonary vein isolation (PVI) is an important treatment for atrial fibrillation (AF). However, many patients need more than one procedure to maintain long-term sinus rhythm. Even after two PVIs some may suffer from AF recurrences. We aimed to identify characteristics of patients who fail after two PVI procedures.Methods and resultsWe included 557 consecutive patients undergoing a first PVI procedure with a second-generation 28 mm cryoballoon. Follow-up procedures were performed using radiofrequency ablation targeting reconnected PVs only. Recurrent AF was defined as any episode of AF lasting >30 s on ECG or 24 hour Holter monitoring performed at 3, 6 and 12 months post procedure. Mean age was 59.1±10.2 years, 383 (68.8%) were male, 448 (80.4%) had paroxysmal AF and the most common underlying condition was hypertension (36.6%). A total of 140/557 (25.1%) patients underwent redo procedure with PVI only. Of these patients 45 (32.4%) had recurrence of AF. These patients were comparable regarding age and sex to those in sinus rhythm after one or two procedures. Multivariate logistic regression showed that non-paroxysmal AF (OR 1.08 (95% CI 1.01 to 1.15), estimated glomerular filtration rate (OR 0.96, 95% CI 0.94 to 0.99), bundle branch block (OR 4.17, 95% CI 1.38 to 12.58), heart failure (OR 4.17, 95% CI 1.38 to 12.58) and Left Atrium Volume Index (OR 1.04, 95% CI 1.01 to 1.08) were associated with AF recurrence after two PVIs. The area under the curve for the identified risk factors was 0.74.ConclusionsUsing a PVI-only approach, recurrence of AF after two AF ablation procedures is associated with more advanced underlying disease and persistent types of AF.

787 Ablation of the ventricular ectopic foci: a therapeutic option for dilated cardiomyopathy due to arrhythmic MVP

Aims A subset of patients with mitral valve prolapse (MVP) are affected by a still not well understood condition characterized by frequent ventricular arrhythmias (mostly originating from papillary muscles) and sudden cardiac death (SCD). It is called MVP malignant syndrome (MVP MS). In these patients, the high arrhythmic burden may lead to left ventricular (LV) dyssynchrony and dysfunction, determining a tachycardia-induced cardiomyopathy (TIC). Reduction in arrhythmic burden determines LV recovery and ejection fraction improvement and interrupts LV progressive dilatation. Methods and reports We report the case of a 52-year-old woman with MVP and family history of both MVP and SCD who was referred to our department for symptomatic extrasystoles and dyspnoea during exercise. Palpitations begun 11 years before: in that occasion she performed a 3-lead-ECG-Holter monitoring which documented 3457 ventricular extrasystoles. Transthoracic echocardiography (TTE) showed normal LV dimension and function and a myxomatous mitral valve with prolapse of both leaflets. At that time beta-blocker therapy was introduced, but soon suspended because of patient’s clinical intolerance (bradycardia and hypotension). Since then she was lost at follow-up for years, until symptoms worsened. When she came to our attention, TTE showed dilated and hypokinetic LV (ejection fraction was 38%, S2 wave at TDI was 6.4 cm/s and global longitudinal strain value was −13%). CMR was performed and confirmed TTE findings. Mitral-annulus disjunction was described in anterior, lateral, and posterior wall and late gadolinium enhancement analyses showed subendocardial fibrosis in correspondence of the posterior papillary muscle (PM) and in the mid-inferior wall. Holter monitoring enlightened a high arrhythmic burden with 24 065 premature ventricular complexes (PVCs) of two morphologies (right bundle branch block-like and −120° axis and right bundle branch block-like and −75° axis). During stress test, PVCs increased as the heart rate increased, resulting in bigeminism at peak exercise. Considering all these features, we hypothesized a case of MVP MS in which the high ventricular arrhythmic burden resulted in TIC. Any available pharmacological attempt to reduce arrhythmias failed. Transcatheter (TC) ablation of PVCs was then proposed. Electrophysiological study identified the inner part of the posterior papillary muscle implantation region and the antero-lateral basal wall as PVCs sites of origin. Radiofrequency ablation was performed in both sites. After the procedure, despite an incomplete suppression of the posterior PM focus, 12-lead 24-h Holter monitoring and TTE performed during the hospitalization showed a consistent arrhythmic burden reduction and LV function improvement. At 6 months from the procedure, symptoms improved and Holter monitoring showed 7515 PVCs with a 54% arrhythmic burden reduction compared with the presentation. TE showed lower LV end-diastolic volume and an increase in ejection fraction up to 47%; global longitudinal strain was −17% and TDI showed a S2 wave on lateral wall of 11 cm/s, confirming left ventricle improvement after the arrhythmic burden reduction. Conclusions Complete suppression of PMs PVCs with TC ablation is difficult to obtain, especially when the focus is in the inner part of the PM and TC ablation of ventricular arrhythmias in MVP patients has not yet demonstrated his efficacy in reducing SCD. Nevertheless, it should be taken into consideration to obtain at least PVCs reduction in patients with high arrhythmic burden leading to TIC.

245 Arrhythmogenic cardiomyopathy in children according to ‘padua criteria’: single paediatric centre experience

Aims Arrhythmogenic cardiomyopathy (ACM) is a rare disease in children. The purpose of this study is to describe the main features of our paediatric patients with ACM providing a contribution for diagnostic work-up and therapeutic decisions. Methods and results Eligibility criteria of the study was ACM diagnosed at age &lt;18 years old. We enrolled 21 patients (mean age at diagnosis 13.9 ± 2 years). Holter monitoring showed premature ventricular complexes (PVCs) burden of 7.9 ± 10% (range: 1–35%). Exercise testing showed suppression of PVCs during exercise in most patients (44.4%). Cardiac magnetic resonance was performed in 17/21 (81%) patients. Right ventricular (RV) dilatation, segmental wall motion abnormalities, and late gadolinium enhancement of both ventricles were the predominant features. Genetic results were available in 19/21 patients. 3/19 (15.8%) had compound heterozygous variants, 3/19 (15.8%) digenic variants, and 6/19 (31.6%) a single variant. EPS was performed in 15/21 (75%). Ventricular tachycardia was inducible in 3/15 (20%) and ventricular fibrillation occurred in 1/15 (6.7%). Implantable cardiac defibrillators (ICDs) were implanted in 15 patients (71.4%). ICD therapies were released in two patients during follow-up (2009–2021). No patients died suddenly. Conclusions Paediatric ACM can be diagnosed in the majority of cases secondary to: incidental finding of minor arrhythmias or due to positive family history. PVCs burden is not elevated and exercise-induced arrhythmias occur in a minority of patients. ICD may be indicated in most patients even if follow-up during the paediatric age can be reassuring. Multicentric observation is highly needed to derive conclusions in children.