Narrow Complex Research Articles

Role of Ultrasound-Guided Evaluation of Dyspnea in the Coronavirus Disease 2019 Pandemic

Role of Ultrasound-Guided Evaluation of Dyspnea in the Coronavirus Disease 2019 Pandemic

Inadvertent triggering of supraventricular tachycardia during pacemaker interrogation: Time to lose the magnet?

A 22-year-old male had a dual chamber permanent pacemaker (PPM) implanted for complete heart block following aortic valve replacement for Shone’s syndrome 3 months previously. He presented with acute shortness of breath due to severe para-valvular leak with aortic valve dehiscence following a motor vehicle accident. He was scheduled for redo sternotomy and a pre-operative PPM check was undertaken. A programmer wand (Model 2067, Medtronic Inc., Minneapolis, MN, USA) was applied to the patient's PPM site to perform interrogation. During initialization, asynchronous DOO pacing at the magnet rate of 85 bpm was initiated with evidence of both atrial and ventricular capture. Competition from intrinsic rhythm resulted in functional loss of capture. Competitive pacing initiated a narrow complex supraventricular tachycardia at 180 bpm. The tachycardia persisted to result in clinical deterioration until reversion with urgent intravenous metoprolol. Programmer wands from Medtronic (Model 2067 & Encore) and Biotronik (Renamic, Biotronik Inc., Berlin, Germany) have in-built magnets that can cause asynchronous pacing during initialization of interrogation. Removing the magnet in future iterations of PPM programmer wands will mitigate inadvertent arrhythmia induction.<Learning objective: Some pacemaker programmer wands contain in-built magnets that can initiate asynchronous pacing when placed over a cardiac implantable electronic device. This could result in asynchronous pacing and inadvertent triggering of arrhythmia. This risk can be minimized by placing the wand after the programmer is booted up to reduce the duration of asynchronous pacing. Device manufacturers should consider redesigning their products to make magnets redundant in future models of programming wands.>

Using Eye-Tracking to Understand Human Responses to Traditional Neighborhood Designs

ABSTRACT New research in brain and cognitive science is changing how we understand how people perceive and experience the built environment, offering key opportunities for urban planning, urban design, and architecture. Sixty-three college students looked at different scenes of New York City public buildings in a set up with an eye tracker in front of a monitor displaying images. Half of the images had design characteristics exemplary of traditional neighborhood design (TND) (like narrow streets, complex facades, and bilateral symmetry). Subjects tended to show greater eye fixation on building fenestration in TND environments, as opposed to the non-TND environments.

Case Report: Exercise-Induced Supraventricular Tachycardia in a 16-Year-Old Boy with Tricuspid Regurgitation

Supraventricular tachycardia (SVT) is a tachydysrhythmia that is often found in pediatric patients which requires treatment. In contrast to sinus tachycardia, SVT is not a normal compensatory response to physiologi-cal stress. This article discusses the case of supraventricular tachycardia in a 16-year-old boy, which appear during strenuous exercise. In this case a guide was also provided in identifying SVT, excluding the differential diagnosis for narrow complex tachycardia, followed by guidelines for the management of pediatric tachycardia based on the Pediatric Advanced Life Support algorithm.

DISORDERS OF CARDIAC RHYTHM IN PATIENTS WITH PRE-EXCITATION SYNDROME OF VENTRICLES AND THEIR PHARMACOLOGICAL CORRECTION

The aim of the research was to analyze the possibility of using different antiarrhythmic agents in patients with pre-excitation syndrome and disorders of cardiac rhythm. Most typical disorders of cardiac rhythm in patients with pre-excitation syndrome are orthodromic reciprocating supraventricular tachycardia, antidromic supraventricular tachycardia, atrial fibrillation and atrial fibrillation. During attack of tachycardia in patients with syndrome of pre-excitation, different clinical symptoms can be observed. They can range from mild palpitation to syncope. This tachycardia can be even reason of sudden cardiac death. Main its mechanism is macroreentrant circuit involving the AV-node, the additional pathway, the atria, the ventricles. To arrest the attacks of atrioventricular reciprocating tachycardia in patients with WPW syndrome and with narrow complexes QRS, calcium channel blocker verapamil has efficacy in 95% of patients. However, for treatment this arrhythmia with wide complexes QRS verapamil is contraindicated. Besides, it should be taken in account that treatment with this type of cardiac arrhythmia cardiac glycosides is also forbidden. Verapamil and cardiac glycosides are contraindicated for termination of arrhythmia in patients with WPW syndrome and such disorders of cardiac rhythm as atrial fibrillation (flutter). For therapy of atrial fibrillation (flutter) in patients with WPW syndrome antiarrhythmic agents of agents of І A subclass (quinidine, procainamide, disopyramide, propafenone) and ІІІ class (amiodarone, sotalol) can be useful. For interruption of paroxysmal tachycardia in patients with pre-excitation syndrome antiarrhythmical preparations of plant origin (gilurytmal and allapinin) have high efficacy. Termination of paroxysmal tachycardia in patients with premature excitation of ventricles can be achieved after administration of antiarrhythmic agents of ІС subclass, in particular after using of propafenone and encainide. However, treatment with the help of these agents quite often leads to appearance of arrhythmogenic action. In pre-excitation syndrome and cardiac arrhythmias, it is impossible to use drugs, which cause the acceleration of conductivity of nerve impulses in additional pathways (cardiac glycosides, β-blocker agents, for example propranolol). In patients with paroxysmal atrioventricular reciprocating (circular) tachycardia digitalis and calcium channel blockers should be avoided. Such agents as digoxin and verapamil in this arrhythmia can turn out to be dangerous in WPW syndrome, since they raise the conductivity through additional conductive pathways.

Approach to narrow complex tachycardia: non-invasive guide to interpretation and management

### Learning objectives Narrow QRS complex tachycardia (NCT) represents an umbrella term for any rapid cardiac rhythm greater than 100 beats per minute (bpm) with a QRS duration of less...

Transient narrowing of a wide QRS tachycardia. What is the mechanism?

Electrocardiogram showing a regular wide QRS tachycardia with left branch block (LBBB) like in morphology at 200 beats per minute (bpm). During electrophysiology study, it suddenly gets narrow and faster. What is the mechanism of the switch from a broad complex to a narrow complex tachycardia?

THE NARROW YET NOT SO NARROW VENTRICULAR TACHYCARDIA

Ventricular tachycardia (VT) usually refers to a three or more consecutive premature ventricular complexes at a rate greater than 100 beats per minute. The prevalence of VT is 9% in men and 8% in women. VTs can sometimes be narrow complex and are often misdiagnosed as Supraventricular tachycardias (

THE DEVIL’S IN THE RATES: ADENOSINE CONVERTING ATRIAL FLUTTER WITH 1:1 CONDUCTION INTO A WIDE COMPLEX TACHYCARDIA

Flecainide can reduce the rate of Atrial Flutter (AFL) which allows for 1:1 conduction through the AtrioVentricular (AV) node. A 57-year-old male with a history of atrial fibrillation (AF) on flecainide, presented with narrow complex tachycardia. He received adenosine 12 mg IV which resulted in

NARROW COMPLEX TACHYCARDIA IS NOT ALWAYS SUPRAVENTRICULAR

Narrow complex tachycardia (NCT) represents rapid, synchronous, biventricular activation that is only achieved by conduction over an intact His-Purkinje system. Not all NCT is supraventricular tachycardia (SVT). An 87 year old man with idiopathic pulmonary fibrosis and coronary artery disease

Wide complex tachycardia cycle length shorter than the narrow complex tachycardia. What is the mechanism?

15-Year-old man's cardiac event monitor showed an episode of wide complex tachycardia which transitioned into narrow complex tachycardia. The tachycardia cycle length was shorter during wide complex tachycardia compared with narrow complex tachycardia. He underwent electrophysiology study in which an orthodromic atrioventricular reentrant tachycardia (wide and narrow complex tachycardia) utilizing left posterolateral bypass tract was induced. We propose the mechanism for shorter tachycardia cycle length during wide complex tachycardia compared with narrow complex tachycardia.

Incidence, clinical, electrophysiological characteristics and outcomes of patients with Wolff-Parkinson-White syndrome and atrial fibrillation

Aims and objectivesAtrial fibrillation (AF) with preexcitation can be life threatening. Our study evaluated the incidence, clinical features, electrophysiologic characteristics and outcomes of patients presenting with AF and fast ventricular rates associated with an antegrade conducting accessory pathway. MethodsHospital data of patients who had undergone electrophysiology study and radiofrequency ablation for AF and Wolff-Parkinson-White (WPW) syndrome was retrospectively evaluated over 10 years and prospective data was further collected over 1 year. Out of 2876 patients undergoing electrophysiology study, 320 patients had manifest preexcitation on ECG. Forty one patients who had presented with AF and fast ventricular rates were included in the study. ResultsForty one (12.8%) patients out of 320 patients of WPW syndrome patients presented with AF and fast ventricular rates. Mean age of presentation was 38.5 ± 12.3 yrs. Twenty nine (72.5%) were male. Most common presenting features were palpitations, presyncope and syncope. Twenty eight (71.1%) patients were electrically cardioverted on presentation, of which two patients having narrow complex tachycardia, when given adenosine, developed AF and fast ventricular rates and had to be electrically cardioverted. Intravenous amiodarone converted AF to sinus rhythm in 11 (28.9%) patients. Right postero-septal pathway (33.3%) followed by coronary sinus epicardial pathway (22.9%) were the most commonly located pathways associated with AF. Five (12.2%) patients had multiple pathways. CS diverticulum was seen in 6 (14.7%) patients. Ablation was done during AF in 6 (14.7%) patients. All except one had immediate successful ablation. One patient had a recurrence of preexcitation on follow up and successfully ablated during redo procedure. ConclusionAF with WPW syndrome is not uncommon. AF is commonly associated with posteriorly located accessory pathways, CS diverticulum and multiple pathways. Radiofrequency ablation has good outcomes.

A Study on Challenges of Tax Revenue Assessment and Collection in Ethiopia with Reference to Custom and Revenue Authority

Tax is a compulsory payment for the government without the expectation of direct benefit or return from tax payers. The world country’s tax revenue is characterizing by high tax rates and narrow tax base, complex and outdated tax law, unrevised and weak tax administration this leads to challenges on the assessment and collection of tax. Tax system complexity has been an issue of concern for stakeholders in developing and advanced countries (Misrak Tesfaye 2014). This paper focuses on to identify on challenges of tax revenue assessment and collection in Ethiopia with reference to custom and revenue authority. The study was employed by using both descriptive and explanatory research design with quantitative and qualitative methods. The quantitative aspect of the data focused on description of socio- economic variables, tax and business related variables and analysis of relationship among the dependent and explanatory variables of the authority. Explanatory research study is most appropriate because it is more efficient, economical and flexible enough to minimize bias and maximize reliability of the collected data. From this study it is found that the factors regarding the tax collector’s the major one, that faced is lack of experience, lack of motivation, unfairness, partiality, and corruption are some of them(Identified through questionnaire). Regarding tax payers were lack of motivation, lack of adequate knowledge, confidence, willingness, are the major ones. Also the model shows the relationship among the dependent and independent variables are significant.

Ivabradine as an Adjunct for Refractory Junctional Ectopic Tachycardia Following Pediatric Cardiac Surgery: A Preliminary Study.

Junctional ectopic tachycardia (JET) is a relatively common narrow complex rhythm typically characterized by atrioventricular dissociation or retrograde atrial conduction in a 1:1 pattern. Junctional ectopic tachycardia can be a life-threatening disorder, causing severe hemodynamic compromise and increased morbidity and mortality. The treatment of refractory JET can be very difficult, even with multimodal therapeutic interventions. The purpose of this study was to assess the role of ivabradine in cases of JET refractory to amiodarone and esmolol. A total of 480 congenital heart surgeries were carried out at our center in 2017. Twenty (4.16%) patients had postoperative JET. Among these, five infants, aged 7 to 12 months (median: 8 months), had refractory JET. These patients (three tetralogy of Fallot, one ventricular septal defect, one complete atrioventricular septal defect) were treated with oral ivabradine in the dose range of 0.1 to 0.2 mg/kg/12 h as an adjunct to amiodarone. All five patients achieved rate reduction and eventual conversion to sinus rhythm. Mean duration to achieve heart rate of <140 bpm after initiation of ivabradine therapy was 16.8 hours (±7.2 hours), while mean duration to achieve sinus rhythm was 31.6 hours (±13.6 hours). No patient had any recurrence of JET. No patient exhibited any hemodynamic derangement nor side effects attributable to oral ivabradine. Oral ivabradine has the potential to be used as an adjunct to amiodarone in the treatment of JET in infants after surgery for congenital heart disease.

Narrow Absorption Lines Complex. III. Gradual Transition from Type S to Type N Broad Absorption Line

Abstract We study the relationship between the broad absorption lines (BALs) that can be decomposed into multiple narrow absorption lines and those that cannot (hereafter Type N and Type S BAL, respectively), based on the analysis of three BAL systems (systems A, B, and C) in two-epoch spectra of quasar SDSS J113009.40+495247.9 (hereafter J1130+4952). As the velocity decreases (from systems A to C), these three BAL systems show a gradual transition from Type S to Type N BAL, and their equivalent widths (EWs) and profile shapes vary in a regular way. We ascribe the absorption line variability in J1130+4952 to the ionization change as a response to the fluctuation of the ionizing continuum based on several factors: (1) coordinated EW strengthening over a wide range in systems A and B, (2) the system B shows an obvious change in Si iv but no significant change in C iv BAL, and (3) asynchronized variability between the continuum and absorption lines. Based on the analysis of the variation mechanism, location, ionization state, and structure of systems A, B, and C, we hold the view that the Type S and Type N BALs in J1130+4952 probe the same clumped outflow, with the Type S BALs originating from the inner part of the outflow with a relatively higher ionization state, smaller column density, and more clumpy structures, while the Type N BALs originate from the outer part of the outflow with relatively lower ionization state, larger column density, and fewer clumpy structures.

Research and design of live maintenance robot for substation equipment

This paper focuses on the reform of the live working mode in substation and the urgent need for the development of safe live working equipments. A multi-agent live maintenance automatic robot has been designed. On the basis of satisfying insulation safety protection requirements, it has flexible operation characteristics, and can independently implement typical live maintenance and detection projects for substation equipments. The robot is appropriate for narrow space and complex working conditions with high precision. Through design, manufacturing, simulation test, field application and other methods, the research and prototype development of this live maintenance robot for substation are carried out from the aspects of operational requirements, structural design and key component design.

Simultaneous cardio-cerebral embolization associated with atrial fibrillation: a case report

BackgroundSimultaneous cerebral and myocardial infarction is called cardiocerebral infarction (CCI), and is rarely encountered. Because of the narrow time window and complex pathophysiology, CCI is challenging to immediately diagnose and treat.Case presentationA 73-year-old woman suddenly developed right hemiplegia and severe aphasia. Twelve-lead electrocardiography showed tachycardic atrial fibrillation without any significant ST-T change. Magnetic resonance imaging revealed a proximal middle cerebral artery occlusion. She was immediately treated with alteplase at the dosage approved for ischemic stroke followed by mechanical thrombectomy as bridging therapy, and complete recanalization was achieved. Aphasia improved and she began to complain of chest pain, and reported that she had experienced chest discomfort just prior to right limb weakness. Coronary angiography showed a partial filling defect in the right coronary artery with rapid and adequate distal flow, for which percutaneous coronary intervention was not required. Alteplase was suggested to have effectively resolved the coronary emboli. The occlusions of the cerebral and coronary arteries were assumed to have occurred nearly simultaneously and cardiogenic embolism due to atrial fibrillation was considered as the most likely etiology.ConclusionsAs seen in the present case, CCI may benefit from immediate treatment with intravenous tissue plasminogen activator (IV-tPA). Although which of percutaneous coronary intervention or cerebral thrombectomy should be performed first remains unclear, we must decide whether to rescue the brain or heart first in each patient within a limited window of time. This dilemma has recently become evident in this era with mechanical thrombectomy strongly established as an effective intervention for acute ischemic stroke. Close cooperation between stroke physicians and cardiologists is becoming more important.

Knowledge of and attitudes to emergency tachyarrhythmia treatment among paramedics and nurses

INTRODUCTION: Supraventricular tachycardia (SVT) is a wide term used to describe tachycardia with atri- al and/or ventricular rates exceeding 100 bpm at rest. The underlying mechanism involves His bundle or tissue lying above. As the diagnosis of SVT is often made in the prehospital settings or in an emergency department, the relevant knowledge of all medical personnel, including paramedics, on the diagnosis and treatment procedures is crucial for the patient’s outcome. It is essential to quickly assess the patient’s clinical condition and make decisions based on both electrocardiographic records and the occurrence of adverse symptoms. Some procedures and pharmacological treatments can be implemented by the paramedic on their own, some require a physician’s supervision. The aim of the study was to assess paramedics’ and nurs- es’ knowledge concerning emergency management in tachycardia. METHODS: The study was conducted in January 2019 in south-western Poland among paramedics and nurses working in the Polish National Emergency Medical System (EMS). All participants received information on the study objectives and voluntarily took part in the questionnaire survey. The questionnaire was developed by the authors and included 22 questions referring to gender, age, work experience, type of work in EMS, number of inhabitants in the workplace area, latest training in advanced life support, adverse events in hemodynamically unstable patients, vagal manoeuvres, European Resuscitation Council 2015 guidelines for narrow and broad complex tachycardia in stable and unstable patients with regular and irregular rhythms, indications for synchronized electrical cardioversion, performing synchronized electrical cardioversion in the past, concerns about cardioversion and self-assessed level of experience in tachyarrhythmia treatment. RESULTS: Overall, 200 paramedics and 50 nurses were asked to participate in the study. The final question- naire return rate was 84.5%. The mean age of the participants equalled as 37.90 ± 11.44 years; 50 (29.59%) were female; the mean work experience was 12.07 ± 10.39 years. The correct treatment in a stable patient with narrow QRS tachyarrhythmia (including vassal manoeuvres and adenosine administration) was pro- posed by 88.17% of the participants. The correct treatment in an unstable patient with broad QRS tachyar- rhythmia was proposed by 84.60% of the participants. Overall, 56.80% indicated correct treatment with a beta-blocker in a stable patient with irregular narrow complex tachyarrhythmia with a duration of over 48 hours; 87.57% knew the role of magnesium sulphate in torsade de pointes treatment. Only 34.91% had conducted electrical cardioversion in the past. According to the subjects, the main problems associated with the procedure of electrical cardioversion were: analgosedation and airway management (52.66%), the risk for sudden cardiac arrest as a result of electrical cardioversion (53.25%), and the risk of a stroke (38.46%). The proper number of electrical cardioversions in unstable patients was proposed by 73.37% of the partic- ipants; 66.86% knew the correct dose of amiodarone when the correct electrical cardioversion sequence does not restore the sinus rhythm and the patient remains unstable. Only 43.79% knew the correct initial biphasic energy for electrical cardioversion in unstable broad complex tachyarrhythmia (120–150 J), while most responders indicated energy up to 120 J. The mean self-assessed level of experience in tachyarrhythmia treatment was 6.00 ± 1.76 in a scale of 0–10, where 0 meant lack of experience and 10 stood for experience ensuring proper performance of the procedure. CONCLUSIONS: The knowledge of Polish paramedics and nurses concerning the emergency treatment of tach- yarrhythmia is unsatisfactory in many aspects. Better undergraduate and postgraduate training on advanced life support guidelines should be recommended.

Safety and Efficacy of Prehospital Diltiazem for Atrial Fibrillation with Rapid Ventricular Response.

Atrial fibrillation (AFIB) with rapid ventricular response (RVR) is a common tachydysrhythmia encountered by Emergency Medical Services (EMS). Current guidelines suggest rate control in stable, symptomatic patients. Little is known about the safety or efficacy of rate-controlling medications given by prehospital providers. This study assessed a protocol for prehospital administration of diltiazem in the setting of AFIB with RVR for provider protocol compliance, patient clinical improvement, and associated adverse events. This was a retrospective, cohort study of patients who were administered diltiazem by providers in the Orange County EMS System (Florida USA) over a two-year period. The protocol directed a 0.25mg/kg dose of diltiazem (maximum of 20mg) for stable, symptomatic patients in AFIB with RVR at a rate of &gt;150 beats per minute (bpm) with a narrow complex. Data collected included patient characteristics, vital signs, electrocardiogram (ECG) rhythm before and after diltiazem, and need for rescue or additional medications. Adverse events were defined as systolic blood pressure &lt;90mmHg or administration of intravenous fluid after diltiazem administration. Clinical improvement was defined as a heart rate decreased by 20% or less than 100bmp. Original prehospital ECG rhythm interpretations were compared to physician interpretations performed retrospectively. Over the study period, 197 patients received diltiazem, with 131 adhering to the protocol. The initial rhythm was AFIB with RVR in 93% of the patients (five percent atrial flutter, two percent supraventricular tachycardia, and one percent sinus tachycardia). The agreement between prehospital and physician rhythm interpretation was 92%, with a Kappa value of 0.454 (P &lt;.001). Overall, there were 22 (11%) adverse events, and 112 (57%) patients showed clinical improvement. When diltiazem was given outside of the existing protocol, the patients had higher rates of adverse events (18% versus eight percent; P = .033). Patients who received diltiazem in adherence with protocols were more likely to show clinical improvement (63% versus 46%; P = .031). This study suggests that prehospital diltiazem administration for AFIB with RVR is safe and effective when strict protocols are followed.Rodriguez A, Hunter CL, Premuroso C, Silvestri S, Stone A, Miller S, Zuver C, Papa L. Safety and efficacy of prehospital diltiazem for atrial fibrillation with rapid ventricular response. Prehosp Disaster Med. 2019;34(3):297-302.

Accurate reconstruction of electric field of ultrashort laser pulse with complete two-step phase-shifting

This paper presents a complete two-step phase-shifting (TSPS) spectral phase interferometry for direct electric-field reconstruction (SPIDER) to improve the reconstruction of ultrafast optical fields. Here, complete TSPS acts as a balanced detection that can not only remove the effect of the dc term of the interferogram, but also reduce measurement noises, and thereby improve the capability of SPIDER to measure the pulses with narrow spectra or complex spectral structures. Some prisms are chosen to replace some environment-sensitive optical components, especially reflective optics to improve operating stability and improve signal-to-noise ratio further. Our experiments show that the available shear can be decreased to 1.5% of the spectral width, which is only about $1/3$ compared with traditional SPIDER.