Complex Tachycardia Research Articles

Utility of smart watches for identifying arrhythmias in children

BackgroundArrhythmia symptoms are frequent complaints in children and often require a pediatric cardiology evaluation. Data regarding the clinical utility of wearable technologies are limited in children. We hypothesize that an Apple Watch can capture arrhythmias in children.MethodsWe present an analysis of patients ≤18 years-of-age who had signs of an arrhythmia documented by an Apple Watch. We include patients evaluated at our center over a 4-year-period and highlight those receiving a formal arrhythmia diagnosis. We evaluate the role of the Apple Watch in arrhythmia diagnosis, the results of other ambulatory cardiac monitoring studies, and findings of any EP studies.ResultsWe identify 145 electronic-medical-record identifications of Apple Watch, and find arrhythmias confirmed in 41 patients (28%) [mean age 13.8 ± 3.2 years]. The arrythmias include: 36 SVT (88%), 3 VT (7%), 1 heart block (2.5%) and wide 1 complex tachycardia (2.5%). We show that invasive EP study confirmed diagnosis in 34 of the 36 patients (94%) with SVT (2 non-inducible). We find that the Apple Watch helped prompt a workup resulting in a new arrhythmia diagnosis for 29 patients (71%). We note traditional ambulatory cardiac monitors were worn by 35 patients (85%), which did not detect arrhythmias in 10 patients (29%). In 73 patients who used an Apple Watch for recreational or self-directed heart rate monitoring, 18 (25%) sought care due to device findings without any arrhythmias identified.ConclusionWe demonstrate that the Apple Watch can record arrhythmia events in children, including events not identified on traditionally used ambulatory monitors.

Hidden in plain sight: complex tachycardias in a young thalassaemia patient

Click to increase image sizeClick to decrease image size Disclosure statementNo potential conflict of interest was reported by the author(s).

Kardiotoksičnost doksorubicina - uzroci, dijagnostika, posledice i mogućnosti prevencije

Introduction: Doxorubicin is an antibiotic from the anthracycline group, with clinical use limited by adverse reactions, primarily cardiotoxicity. Material and Methods: This article provides an overview of therapeutic and toxic doses of doxorubicin, the mechanism of side effects, markers for early detection as well as currently available preparations for preventing its toxicity. We searched PubMed, Google Scholar, SCIndex, Dimension, Scopus and Google for English and Serbian language abstracts, using the searching terms "doxorubicin", "cardiotoxicty", "carotenoids", "oncology", "oxidative stress", "DNA damage" and "biomarkers". Topic: The mechanism of side effects is still unclear and is considered to be multifactorial including ROS overproduction, reducing levels of endogenous antioxidants, DNA damage, large drug accumulation in cardiac tissue, calcium overload, histamine release, and impairment of autoimmune regulation of cardiac function Manifestations of cardiotoxicity are mainly acute (appear inside 24h atypical changes of ST segment, decrease in QRS complex voltage, tachycardia and supraventricular extrasystoles are observed, but can also be subacute and chronic (cardiomyocyte edema, disorganzation, fibroblast proliferation, necrosis). Diagnosis of cardiotoxicity is based on ECG, ECHO, and biochemical markers, among which the most important are troponins, while pathohistological verification is necessary for the final diagnosis. Some medications (carvedilol, atorvastatin) have showed some level of cardioprotection against DOX, but there is no overall agreement on their administration solely for this purpose. An increasing number of studies have tested various dietary supplements and natural preparations (already in the human diet) in order to discover those that could completely prevent or reduce the toxic effects of doxorubicin, with special focus on carotenoids. Conclusion: Cardiotoxicity is the leading side effect of doxorubicin, and therefore there is an active search for either new biomarkers and/or diagnostic protocols that would detect toxicity in time, as well as substances able to prevent the occurrence or alleviate DOXinduced cardiotoxicity.

Successful high-resolution left atrial mapping and catheter ablation of a complex supraventricular tachycardia with transseptal passage through an atrial shunt device

Successful high-resolution left atrial mapping and catheter ablation of a complex supraventricular tachycardia with transseptal passage through an atrial shunt device

Avaliação de arritmias em cavalos atletas com baixo desempenho

O objetivo deste estudo foi correlacionar a importância de arritmias em cavalos de corrida Puro Sangue Inglês com baixo desempenho. Foram avaliados 16 equinos (10 machos e 6 fêmeas), com idade entre 2 e 6 anos e pesando 474,5 ± 39,4kg. Estes foram selecionados de acordo com a ocorrência ou não de baixo desempenho, em grupos: grupo baixo desempenho (BD) e grupo controle (CTL). Procedeu-se ao exame eletrocardiográfico contínuo (Holter), sendo avaliados em repouso e em exercício, padronizado para todos. Foram observadas arritmias em ambos os grupos, classificadas como bloqueio atrioventricular de segundo grau (BAV2), bloqueio sinusal (BS), complexo pré-ventricular prematuro (CPVP), complexo ventricular prematuro (CVP) e taquicardia ventricular (TV). BAV2 foi a arritmia mais frequente com média de 1,91 BAV2/h no grupo BD e 3,8 BAV2/h no grupo CTL. Quanto a ocorrência de BS, a média foi 0,76 BS/h no grupo BD e 0,72 BS/h no grupo CTL. Complexo pré-ventricular prematuro obteve média 0,12 CPVP/h no grupo CTL e 0,21 CPVP/h no grupo BD. A comparação de ocorrência de BAV2, BS, CPVP e DVP em ambos os grupos, não obteve diferença estatística significativa. Os resultados sugerem que não houve influência dessas arritmias no baixo desempenho dos animais avaliados.

First experience and validation of the extended early meets late (EEML) tool as part of the novel CARTO software HD COLORING.

With CARTO HD COLORING, a new enhanced software-based map visualization is available to highlight among others potential areas of conduction block in complex arrhythmias (extended early meets late (EEML)). The ideal settings of thresholds are still unclear and are examined here by studying 12 left atrial arrhythmias. Ten patients with left atrial tachycardia underwent high-density activation mapping of the left atrium. Areas of local conduction block were visualized with different extended early meets late (EEML) thresholds (75/25%; 80/20%; 85/15%; 90/10%) and compared with ripple maps for verification. Settings of 80/20% or 85/15% were more accurate than the default settings of 75/25% in displaying the actual amount of conduction block as assessed by ripple maps. HD COLORING leads to further insights into complex tachycardias through a new Voxel Map Surface Concept and color-based visualization of local conduction block. It can be assumed that individual adaption of extended early meets late (EEML) thresholds should be applied for a more accurate visualization of local conduction block.

P5757Mapping and ablation of complex left atrial tachycardia using an automated high resolution mapping algorithm

P5757Mapping and ablation of complex left atrial tachycardia using an automated high resolution mapping algorithm

Use of panoramic body surface electrocardiographic for mapping of tachyarrhythmias in adult patients with congenital heart disease

Introduction: In patients with congenital heart disease the complex underlying anatomy and dilatation of the cardiac chambers demands extensive invasive intracardiac mapping. We assessed the clinical utility of a novel noninvasive, single beat simultaneous electrocardiographic mapping system (ECVUE™) in diagnosing complex and/or multiple tachycardias in this population. Methods: Consecutive patients with congenital heart disease and previous endocardial ablation procedures were selected. Noninvasive body surface ECVUE™ simultaneous spatial mapping was performed both pre- and intra-procedurally to localize the arrhythmia origin and to guide ablation. Results: Six patients (4 female) with a median age of 28 years were studied. Patients' anatomical background included left atrial isomerism, DTGA post arterial switch, pulmonary atresia, surgically repaired partial AVSD, pulmonary stenosis with Waterston shunt and Ebstein's anomaly. Non-invasive ECVUE™ evaluated 13 arrhythmias across the 6 patients (2.17 arrhythmias/patient) and correctly diagnosed the region of interest in 12 of 13 (92%) arrhythmias. Median procedure duration and fluoroscopy time were 233 min and 14 min, respectively. Remote magnetic navigation was used in 2 procedures. Acute ablation success was achieved in 5 of 6 patients, and in 11 of 13 arrhythmias. ![Figure][1] Figure 1 Conclusions: Non-invasive panoramic mapping, via ECVUE™, is a novel tool for evaluating complex arrhythmias, particularly helpful in patients with congenital anomalies and previously failed ablation. It can be used in conjunction with other technologies such as remote magnetic navigation, facilitates ablation of multiple arrhythmias in single procedure, with no longer than expected procedure length or fluoroscopy time. [1]: pending:yes

Epicardial and endocardial mapping determine most successful site of ablation for ventricular tachyarrhythmias originating from left ventricular summit

A 34-year-old woman presented with idiopathic premature ventricular complex (PVC) and ventricular tachycardia (VT) originating from the area called the left ventricular summit. Radiofrequency (RF) application both through the coronary sinus and to the epicardial surface transiently suppressed the VT/PVC. Radiofrequency with sufficient energy was only applicable from the endocardial site, and the VT/PVC was successfully eliminated.

Evidence-based guidelines address peri-arrest arrhythmias

In Brief Revised guidelines provide treatments for commonly occurring peri-arrest arrhythmias, including narrow-complex tachycardia, wide- (broad-) complex tachycardia, and bradycardia.

Relation between exercise-induced ventricular arrhythmias and myocardial perfusion abnormalities in patients with intermediate pretest probability of coronary artery disease.

The significance of exercise-induced ventricular arrhythmias (VAs) is largely dependent on the clinical characteristics of the studied population. The relation between exercise-induced VAs and myocardial perfusion abnormalities has not yet been evaluated in a homogeneous patient population with intermediate probability of coronary artery disease (CAD). We studied 302 patients (mean age 54+/-9 years, 152 men and 150 women) with intermediate pretest probability of CAD (range=0.25-0.80, mean=0.43+/-0.20) by upright bicycle exercise stress test in conjunction with technetium-99m single-photon emission tomography (SPET) imaging. Exercise-induced VAs (frequent or complex premature ventricular contractions or ventricular tachycardia) occurred in 65 patients (22%). No significant difference was found between patients with and patient without VAs regarding the pretest probability of CAD (0.45+/-0.21 vs 0.43+/-0.20). Patients with exercise-induced VAs had a higher prevalence of perfusion abnormalities (52% vs 26%, P=0.002) and ischaemic electrocardiographic changes (31% vs 16%, P<0.05) compared to patients without VAs. A higher prevalence of perfusion abnormalities in patients with VAs was observed in both men (67% vs 35%, P<0.01) and women (38% vs 16%, P<0.05). However, the positive predictive value of exercise-induced VAs for the presence of myocardial perfusion abnormalities was higher in men than in women (67% vs 38%, P<0.05). The presence of abnormal myocardial perfusion was the only independent predictor of exercise-induced VAs (OR 2.2; 95% CI, 1.2-4.2) by multivariate analysis of clinical and stress test variables. It is concluded that in patients with intermediate pretest probability of CAD, exercise-induced VAs are predictive of a higher prevalence of myocardial perfusion abnormalities in both men and women. However, the positive predictive value of exercise-induced VAs for perfusion abnormalities is higher in men. Because of the underestimation of ischaemia by electrocardiographic changes, exercise-induced VAs should be interpreted as a marker of a higher probability of CAD.

Adenosine in Wide-Complex Tachycardia

The use of adenosine as a therapeutic and diagnostic tool in wide- complex tachycardia is suggested in the current Advanced Cardiac Life Support (ACLS) guidelines. The ACLS guidelines are now 4 years old, and new information on the safety and efficiency of adenosine in wide-complex tachycardia is available. We review the ACLS recommendations in light of the current available literature. In general, the ACLS recommendations remain reasonable with some important caveats. [Herbert ME, Votey SR: Adenosine in wide-complex tachycardia. Ann Emerg Med January 1997;29:172-174.]