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, Single-Centre Observation of Patients with Cardiac Implantable Electronic Devices

Background and Objectives: Electrotherapy is a valuable treatment method for patients with heart rhythm disturbances. There are very few observations of long-term patients treated with these techniques. There is a particular lack of this type of study conducted in Eastern European countries. The aim of this single-centre analysis was to evaluate the long-term survival (from 2010 to 2018) of patients treated with electrotherapy devices, taking into account clinical factors facilitating the prognosis of these patients. Materials and Methods: The patients (N = 2071) subsequently included in the study were subjected to the implementation or replacement of cardiac pacemakers. The medical records of all the patients were analysed. Data concerning death, made available by the State Systems Department of the Ministry of Administration and Digitization, were used. Results: The patients with VVI pacemakers had the worst prognosis after the replacement of the devices. Male patients had a worse prognosis, regardless of the kind of device implanted. Advanced atrioventricular conduction disturbances, chronic kidney disease, and hypothyroidism with reduced left ventricular ejection fraction were among the most significant coexisting diseases. Conclusions: The long-term prognosis of patients under different forms of electrotherapy remains poor. Despite the more straightforward technique, a single-chamber device (VVI/AAI) or generator replacement leads to the worst prognosis. The complexity of the clinical picture that stems from coexisting diseases and advanced age is of the utmost importance.

Predictors of Conduction Disturbances after Transcatheter Aortic Valve Implantation with Balloon-expandable Valve for Bicuspid Aortic Valve Stenosis

Objective: The implantation depth and membranous septum (MS) length are established as the predictors of new-onset conduction disturbance (CD) after transcatheter aortic valve replacement (TAVR) for tricuspid aortic valve (TAV) stenosis. However, little is known about the predictors with bicuspid aortic valve (BAV). This study investigated the role of MS length and implantation depth in predicting CD following TAVR with a balloon-expandable valve in patients with BAV. Methods and results: This retrospective study analyzed 169 patients who underwent TAVR for BAV with balloon-expandable valve, and TAV cohort was established as a control group using propensity score (PS) matching. The primary endpoint was in-hospital new-onset CD (new-onset left bundle branch block or new permanent pacemaker implantation). New-onset CD developed in 37 patients (21.9%). Multivariate analysis revealed severe LVOT calcification (Odds ratio [OR]: 5.83, 95% confidence interval [CI]: 1.08 – 31.5, p = 0.0407) and implantation depth – MS length (OR: 1.30, 95% CI: 1.12 – 1.51, p = 0.0005) as the predictors of new-onset CD within BAV cohort. The matched comparison between BAV and TAV groups showed similar MS length (3.0 vs 3.2mm, p = 0.5307), but valves were implanted deeper in BAV than TAV group (3.9 vs 3.0mm, p < .0001). New-onset CD was more frequent in patients having BAV (22.3% vs 13.9%, p = 0.0458). Conclusion: The implantation depth - MS length, and severe LVOT calcification predicted new-onset CD following TAVR in BAV with balloon-expandable valve. High implantation technique could be considered to avoid new-onset CD in BAV anatomy.

398 Right ventricular cardiogenic shock induced by propafenone intoxication: a case report

Aims Propafenone is a Class 1C antiarrhythmic drug recommended in the treatment of supraventricular or ventricular tachycardia and paroxysmal atrial fibrillation (AF). Most common cardiological features associated with propafenone intoxication include heart failure and conduction disturbances while other clinical findings range from nausea and vomiting to seizures and coma. Methods We report a case of atypical presentation of propafenone intoxication occurred in 88-year-old woman who presented at Emergency Department with severe ECG abnormalities and prevalent acute right ventricular with massive tricuspidalic regurgitation and cardiogenic shock. The patient underwent urgent coronary angiography that revealed a stable 90% coronary plaque that was treated with a single stent and then brought to Intensive Care Unit where she was successfully treated with inotropic and mechanical circulatory support (intra-aortic balloon pump, IABP). Results The patient progressively achieved hemodynamic stability with complete ECG normalization and biventricular function recovery. Conclusions Our case further expands the vast spectrum of presentations of Class 1c antiarrhythmic drugs overdose. In an emergency setting it is difficult to rule out other causes of cardiogenic shock but propafenone toxicity needs to be suspected in every case of hemodynamic instability in patients in chronical treatment. Patients in chronical treatment with propafenone who have kidney or liver dysfunction might be at higher risk of drug accumulation: in such cases, the real utility of propafenone must be evaluated before therapy initiation.

Analysis of Indications for Electrotherapy Using Classification Trees

Electrotherapy is a dynamically developing method of treatment of sinus node dysfunction and atrioventricular conduction disturbances. It is an extremely important method used in the treatment of heart failure. The aim of this paper was to use classification trees for the differentiation between patients implanted with one of the three electrotherapy devices, i.e. SC-VVI/AAI, DC-DDD, ICD/CRT. The analysed data concerned 2071 patients who underwent implantation or device replacement procedures in the years 2010–2018, hospitalized in a coronary care unit. CART-type classification trees with 5-fold cross-validation were used for the analysis. The decision concerning the choice of a particular electrotherapy device is always made based on the latest guidelines and the patient’s clinical condition. The used classification trees may enable verification of the state of implementation of guidelines in real-life therapeutic decisions.

The Predictors of Conduction Disturbances Following Transcatheter Aortic Valve Replacement in Patients With Bicuspid Aortic Valve: A Multicenter Study

Objective: To evaluate the predictors of new-onset conduction disturbances in bicuspid aortic valve patients using self-expanding valve and identify modifiable technical factors.Background: New-onset conduction disturbances (NOCDs), including complete left bundle branch block and high-grade atrioventricular block, remain the most common complication after transcatheter aortic valve replacement (TAVR).Methods: A total of 209 consecutive bicuspid patients who underwent self-expanding TAVR in 5 centers in China were enrolled from February 2016 to September 2020. The optimal cut-offs in this study were generated from receiver operator characteristic curve analyses. The infra-annular and coronal membranous septum (MS) length was measured in preoperative computed tomography. MSID was calculated by subtracting implantation depth measure on postoperative computed tomography from infra-annular MS or coronal MS length.Results: Forty-two (20.1%) patients developed complete left bundle branch block and 21 (10.0%) patients developed high-grade atrioventricular block after TAVR, while 61 (29.2%) patients developed NOCDs. Coronal MS &lt;4.9 mm (OR: 3.08, 95% CI: 1.63–5.82, p = 0.001) or infra-annular MS &lt;3.7 mm (OR: 2.18, 95% CI: 1.04–4.56, p = 0.038) and left ventricular outflow tract perimeter &lt;66.8 mm (OR: 4.95 95% CI: 1.59–15.45, p = 0.006) were powerful predictors of NOCDs. The multivariate model including age &gt;73 years (OR: 2.26, 95% CI: 1.17–4.36, p = 0.015), Δcoronal MSID &lt;1.8 mm (OR: 7.87, 95% CI: 2.84–21.77, p &lt; 0.001) and prosthesis oversizing ratio on left ventricular outflow tract &gt;3.2% (OR: 3.42, 95% CI: 1.74–6.72, p &lt; 0.001) showed best predictive value of NOCDs, with c-statistic = 0.768 (95% CI: 0.699–0.837, p &lt; 0.001). The incidence of NOCDs was much lower (7.5 vs. 55.2%, p &lt; 0.001) in patients without Δcoronal MSID &lt;1.8 mm and prosthesis oversizing ratio on left ventricular outflow tract &gt;3.2% compared with patients who had these two risk factors.Conclusion: The risk of NOCDs in bicuspid aortic stenosis patients could be evaluated based on MS length and prosthesis oversizing ratio. Implantation depth guided by MS length and reducing the oversizing ratio might be a feasible strategy for heavily calcified bicuspid patients with short MS.

Electrophysiological Consequences of Cardiac Fibrosis

For both the atria and ventricles, fibrosis is generally recognized as one of the key determinants of conduction disturbances. By definition, fibrosis refers to an increased amount of fibrous tissue. However, fibrosis is not a singular entity. Various forms can be distinguished, that differ in distribution: replacement fibrosis, endomysial and perimysial fibrosis, and perivascular, endocardial, and epicardial fibrosis. These different forms typically result from diverging pathophysiological mechanisms and can have different consequences for conduction. The impact of fibrosis on propagation depends on exactly how the patterns of electrical connections between myocytes are altered. We will therefore first consider the normal patterns of electrical connections and their regional diversity as determinants of propagation. Subsequently, we will summarize current knowledge on how different forms of fibrosis lead to a loss of electrical connectivity in order to explain their effects on propagation and mechanisms of arrhythmogenesis, including ectopy, reentry, and alternans. Finally, we will discuss a histological quantification of fibrosis. Because of the different forms of fibrosis and their diverging effects on electrical propagation, the total amount of fibrosis is a poor indicator for the effect on conduction. Ideally, an assessment of cardiac fibrosis should exclude fibrous tissue that does not affect conduction and differentiate between the various types that do; in this article, we highlight practical solutions for histological analysis that meet these requirements.