Case Of Flutter Research Articles

Result and technique consideration of radiofrequency catheter ablation of tachycardia in patients with dextrocardia

Patients with tachycardia, in the context of pre-existing dextrocardia, could benefit from catheter ablation. However, anatomical complexities hinder effective conduct of this procedure. We aimed to retrospectively summarize the clinical characteristics and the safety and efficiency, and recommended the technique considerations. Twenty-one cases from 19 patients with tachycardia and dextrocardia, who underwent catheter ablation between 2009 and 2021, were enrolled. All patients underwent echocardiography and computed tomography (CT) to confirm the anatomical malformations. Transseptal puncture was guided by fluoroscopy or intracardiac echocardiography when left atrial access was necessary and the ablation process was guided by three-dimensional (3D) mapping. Six cases exhibited situs solitus while nine cases exhibited situs inversus. Fourteen cases had atrial fibrillation, seven had atrial flutter, and two had atrioventricular reentrant tachycardia (AVRT); two cases had combined atrial fibrillation and atrial flutter. Acute success was achieved in 18 cases (85.7%, 18/21). The 3D mapping system was not employed in the three cases which failed. During long-term follow-up (20.71 ± 21.86 months), eight cases (72.7%, 8/11) of atrial fibrillation with dextrocardia successfully attained sinus rhythm. None of AVRT cases had recurrence. Half of the atrial flutter cases with dextrocardia, especially those with a history of surgical correction for cardiac malformations, underwent recurrence. One case had cardiac tamponade. Catheter ablation for tachycardia patients with dextrocardia is safe, efficient, and feasible. It is imperative to integrate echocardiography, cardiac computer tomography, and 3D mapping, and apply 3D reconstruction to facilitate the success of catheter ablation.

New right bundle branch block after selective HIS bundle pacing, Two methods for correction

HIS Bundle Pacing (HBP) is considered the most physiologic pacing technique as it generates a physiological activation of both ventricles through synchronous ventricular depolarization of His bundle– Purkinje conduction system. Permanent HBP and Atrioventricular Node (AVN) ablation in patients with heart failure and atrial fibrillation were found to have an improvement in cardiac function and reduction of left ventricular dimensions [1]. We present case of paroxysmal atrial fibrillation and atypical atrial flutter that underwent HBP and AVN ablation. The patient developed a Right Bundle Branch Block (RBBB) following his AVN ablation with widening of QRS duration to 148 msec. We managed to correct this and restore a narrow QRS by two different mechanisms: 1. Programming the Interventricular (VV) delay to 20 msec (His pacing first followed by septal RV pacing through a back-up lead, 2. Unipolar pacing of the HIS lead with different configuration. By both methods, QRS duration was reduced to 108-110 msec with restoration of physiologic biventricular pacing. To the best of our knowledge, this has not been reported before. Keywords: atrial fibrillation; his bundle pacing; ablate; pace.

Elevator Tab Model and Aerodynamic Hinge Moment Variation Effect on Flutter Analysis of a Small Commuter Aircraft

Investigation of flutter instability analysis is an important process during design phase and certification of an aircraft. Without proper analysis, the effect of modification at later stage of design process could come at high cost and risk. The present work examines detailed elevator tab model which could result in a more critical tab flutter speed. The present investigation of aerodynamic hinge moment variation effect on flutter analysis also shows a significant decrease in the flutter speeds. Three configurations involving elevator trim tab and balance tab fixed/free mechanism are investigated. Investigation of flutter sensitivity to tab rotational frequency and tab bending/torsion frequency was performed to determine the minimum tab rotational frequency requirement, so that it can be used as reference in design process. Variation of Mach number (for Configuration 1) and elevator aerodynamic hinge moment (all configurations) are performed. It is found that the aerodynamic variation takes effect when the mode involves both trim and balance tabs and tab elastic modes (e.g., tab torsion). It is found also that the most critical flutter case is for Configuration 3 where the trim and balance tabs are not fixed (independent). The result suggests that control surface tabs need to be modelled from the early design process, so that if any critical flutter appears and needs to be responded by a change in design, it can be implemented earlier and therefore avoid any costly risk.

Anaesthetic and Perioperative Management of Elderly Female with Post Covid ARDS with Comorbities Undergoing Emergency Laparotomy for Obstructed Umbilical Hernia

Elderly female with chronic hypertension, known case of atrial flutter on rate control medication who recently treated for COVID-19 pneumonia on oxygen support(PFR=190) came to emergency room with complaints of abdominal mass and pain associated with vomiting, not passing stools. Diagnosed to have obstructed umbilical hernia with extensive secondary bacterial pneumonia with ARDS (ASA-4E). COVID-19 RTPCR test negative. Taken up for emergency laparotomy under combined spinal and epidural anaesthesia (CSEA). Post operatively patient was managed in intensive care unit for 5days with oxygen, invasive lines, vasopressor support and epidural infusion. Post covid patients presenting for emergency surgery requires evaluation of surgical illness and post covid sequels like oxygen dependency, cytokine storm, secondary bacterial infection, ARDS, lung fibrosis renal and liver dysfunction. Atrial flutter in perioperative period may lead to haemodynamic instability and thromboembolic events resulting in significant morbidity and mortality. Laparotomy in these patient is challenge. Needs better analgesia perioperative period to prevent further respiratory deterioration.

Numerical Investigation of Aeroelastic Characteristics of Grid Fin

Grid fin is widely used in the field of aerospace because of its unique advantages in the aerodynamic and structural performance. Meanwhile, the aerodynamic and structural characteristics of the grid fin are quite different from those of the conventional rudder. Deep understanding of the aeroelastic characteristics and mechanism of the grid fin is of great reference value for the fine design of grid fin. In this paper, an efficient reduction-order-method-based aeroelastic analysis method is established, and the method is verified by the flutter case of AGARD 445.6 wing. Finally, based on this method, the flowfield characteristics and the variation of flutter characteristics with Mach number are studied in detail. The results show that in the subsonic region, the transonic flutter “dip” of the grid fin occurs earlier than that of the conventional wing due to the acceleration effect of the grid fin on the airflow. In the transonic region, when the flowfield is characterized by a bow shock wave, the critical flutter speed increases slightly with the increase of Mach number. However, in the supersonic region, when the flowfield is characterized by an oblique shock wave, the flutter critical velocity increases substantially with the increase of Mach number. It is found that the variation law of the flutter boundary with Mach number is very similar to that of the normal force and the pitching moment with Mach number, and there is a close relationship between them. The ratio of flutter speed of the grid fin to the freestream velocity will reach the minimum value near . At the same time, it is discovered that the flutter instability of the grid fin is mainly caused by the coupling of the bending mode and torsional mode of the grid fin, and the instability mode is the torsional mode. Meanwhile, it should be noted that the flutter coupling characteristics of the grid fin differ greatly from those of the conventional rudder surface due to the great difference in structural characteristics and unsteady aerodynamic characteristics.

Atrial flutter in newborns

Objective. To describe a case of atrial flutter in a newborn.Results. The child in the maternity hospital was found to have a heart rhythm disorder of the type: atrial flutter, constant form. Examination revealed an atrial septal defect and an increase in the level of natriuretic peptide. Subsequently, the child was diagnosed with atrial flutter, constant form. NK 0-1. Open oval window. Treatment with drugs from the group of antiarrhythmics, antioxidants and cardiac glycosides made it possible to avoid pronounced hemodynamic disorders.Conclusion. The presented case demonstrates that timely diagnosis and medical correction prevent possible complications.

Тахиаритмия у новорожденных. Клинический случай трепетания предсердий у новорожденного

Актуальность. Тахиаритмии — это наиболее опасное нарушение ритма у новорожденных и детей грудного возраста. Редкой формой тахиаритмии, не характерной для новорожденных, является трепетание предсердий (ТП). ТП у новорожденных встречается с частотой 1 : 50 000 и составляет 3 % от всех нарушений ритма у новорожденных. Цель заключается в исследовании тахиаритмии новорожденных на примере клинического случая трепетания предсердий у новорожденного. Материалы и методы. В этой статье был рассмотрен клинический случай сложного нарушения ритма у новорожденного мальчика, а именно: трепетание предсердий 2 : 1, 3 : 1 с рецидивирующими приступами пароксизмальной наджелудочковой тахикардии, частыми желудочковыми экстрасистолами и пониженной сократимостью миокарда. Для исследования трепетания предсердий были использованы следующие методы: ЭКГ, 2D допплер-ЭхоКГ. Результаты. Медикаментозное лечение данного нарушения ритма состояло в следующем: АТФ в/в болюсно, повторно — неэффективно, инфузия кордарона 15 мг/кг/сут, седация. В связи с нарастанием сердечной недостаточности и низкой сократительной способностью миокарда была добавлена инотропная терапия (дигоксин 20 мкг/кг). В результате синусовый ритм был восстановлен в течение суток. Продлена инфузия кордарона в дозе 10 мг/кг/сут в течение 5 дней с переходом на 5 мг/кг/сут. Таким образом, в динамике по данным ЭхоКГ: уменьшились размеры камер сердца, внутрисердечных аномалий не было обнаружено. Кровоток в нисходящем отделе аорты пульсирующий, улучшилась сократительная способность миокарда: ФВ возросла — 45–50–62–66 %. Более того, на ЭКГ в динамике наблюдалось восстановление синусового ритма с ЧСС 130 уд/мин, без признаков гипертрофии миокарда и нарушений проводимости. Выводы. В нашем случае лечения эпизода ТП новорожденного —восстановление синусового ритма — достигнуто путем медикаментозной терапии. Альтернативным методом лечения ТП у новорожденных является синхронизированная электрическая кардиоверсия 0,5–1,0 Дж/кг [5, 6].

Association between human immunodeficiency virus serostatus and the prevalence of atrial fibrillation.

Atrial fibrillation (AF) leads to increased risk for stroke. Human immunodeficiency virus (HIV) is associated with cardiovascular disease (CVD), although it is unclear if HIV is associated with AF. The purpose of this study was to evaluate the association between HIV serostatus and the prevalence of AF in the Multicenter AIDS Cohort Study.A cross sectional study was conducted among 1674 HIV-infected (HIV+) and uninfected (HIV–) men who completed resting 12-lead electrocardiograms, and/or ambulatory electrocardiogram monitoring. Multivariable logistic regression was used to evaluate the association between AF, defined as the presence of either AF or atrial flutter, and HIV+ serostatus. Associations were adjusted for demographic variables, and then also for CVD risk factors.HIV+ men were younger than HIV– men (median 55.5 vs 61.7 years, P < .001) and were more frequently African-American (30.5% vs 17.8%, P < .001). Most HIV+ men (81%) had undetectable viral load. The age and race adjusted prevalence of AF was 3.0% in HIV+ and 3.3% in HIV– men. There was only 1 case of AF among African-American men. There were no associations between AF and HIV serostatus after adjusting for demographic factors (odds ratio 0.76; 95% CI 0.37 to –1.58; P = .47) or after further adjustment for CVD risk factors (odds ratio 0.84; 95% CI 0.39 to –1.81; P = .66).We found no association between HIV and AF in this cohort in which viral replication among the HIV+ men is generally suppressed. The overall prevalence of AF was low and was rare in African-American men.

Unusual Presentation of Atrial Flutter With Slow Ventricular Response

Atrial flutter is usually associated with tachycardia with a ventricular rate of 150 beats per minute. Less commonly, it may be associated with a slow ventricular response (SVR). This is typically seen in patients taking atrioventricular (AV) nodal blocking agents such as beta-blockers. In the absence of these drugs, atrial flutter with SVR may suggest intrinsic AV nodal disease, electrolyte disturbances, or atrial disease. We present a case of atrial flutter with SVR in a patient who was not receiving AV nodal blocking agents.

The effect of patient characteristics to the acute procedural success and long term outcome of atrial tachycardia and atrial flutter cases undergoing catheter ablation

Objective: In the present study we aimed to demonstrate clinical characteristics, predictors of procedural success and long term recurrence of atrial tachyarrhythmia patients undergoing catheter ablation (CA). Patients and Methods: Consecutive patients who had undergone CA due to an atrial tachyarrhythmia in a single centre arrhythmia unit between 2012 – 2020 were screened. Predictors of procedural success and recurrence were analysed by logistic regression. Results: Study population consisted of 299 consecutive patients (95 [31.8 %] atrial tachycardia, 204 [68.2 %] atrial flutter cases);163 ( 54.5 % ) were male; median age was 54 ( IQR; 42-64). Median follow up was 330 (IQR; 90 – 810) days. Atrial flutter patients were older and had more co-morbidities. Acute procedural success rate was 82.1 % vs. 77.0 % (p= 0.313) and recurrence was 9.3 % vs. 21.6 % (p=0.022) in atrial tachycardia (AT) and atrial flutter (AFL) cases respectively. History of valvular or congenital heart disease surgery, left atrium diameter and age were found to be independent predictors of failed ablation, recurrence and post-procedural atrial fibrillation. Conclusion: Age, left atrium diameter, valvular or congenital heart disease surgery are independent predictors for acute procedural success, recurrence and post-procedural atrial fibrillation in AT and AFL patients who undergo catheter ablation.

Management of Atrial Flutter in Thyroid Storm

Introduction: Thyroid storm, life-threatening hyperthyroidism, commonly presents with tachyarrhythmias. We present a case of hyperthyroid-induced atrial flutter, refractory to beta-blockade, successfully treated with electrical cardioversion (CV) while biochemically hyperthyroid. Case Description: A 49-year-old female with history of asthma and no family or personal history of thyroid disease presented with new-onset atrial flutter and heart failure. The patient endorsed weight loss, hot flashes, anxiousness, tremors, and palpitations. She denied gastrointestinal symptoms or visual changes. She was afebrile with normal mentation. Heart rate was found to be 260 beats per minute (bpm) in atrial flutter. Exam demonstrated bilateral lower extremity edema, and profound exophthalmos. Labs were remarkable for thyroid stimulating hormone (TSH) <0.01 [ref: 0.27-4.2] uIU/mL, free T4 4.5 [ref: 0.8-1.8] ng/dL, free T3 15.5 [ref: 2.0-4.4] pg/mL, thyroid stimulating immunoglobulin (TSI) of 379 [ref: <140] % and a thyroid receptor antibody (TRab) of 10.02 [ref:<=2.0] IU/L. White blood cell count and liver function tests were normal. Chest x-ray (CXR) showed bilateral pulmonary edema and ultrasound showed an enlarged heterogeneous hypervascular thyroid gland. The patient was initially started on Methimazole 30 mg daily and Metoprolol 25 mg every six hours but on day two, the patient was transitioned to Propylthiouracil (PTU) 250 mg every 6 hours given continued atrial flutter and concern for thyroid storm given Burch-Wartofsky score was 50. She was also given potassium iodide for three days. Cardioversion was deferred, as it was felt that the severity of thyrotoxicosis would limit success. On day six, TFTs were improved with a free T4 of 2.2, free T3 3.6. On day 8, because of continued tachycardia >130 bpm with limitation of beta-blockade due to hypotension, she underwent a cardioversion which was successful. On discharge, free T4 was 1.7 and she was transitioned to Methimazole 40 mg daily. Discussion: Thyroid storm has a mortality rate of 10-20%, often related to tachyarrhythmias which can be difficult to treat during a hyperthyroid state. Tachycardia should initially be treated with beta-blockade and antithyroid therapy. Amiodarone is avoided due to concern for worsening hyperthyroidism. A literature review suggests that electrical CV should not be attempted until a patient is euthyroid for four months, as a majority will spontaneously revert once thyroid levels normalize. Conversely, other studies have found that the rate of recurrence of atrial fibrillation between clinically hyperthyroid and euthyroid patients was not statistically significant, suggesting CV should not be delayed until a patient is euthyroid. This suggests that further studies need to be completed to better elucidate appropriate timing in hyperthyroid patient’s refractory to pharmacologic treatment alone.

A Man with Unexplained Cause of Rapid Regular Wide QRS Complex Tachycardia: An Unusual Case Report of Atrial Flutter

Objective: To report an unusual case of atrial flutter with 1:1 atrioventricular (AV) conduction with unclear precipitating factors. Case Report: A 67-year-old Thai male patient presented with diarrhea and palpitation. The electrocardiogram showed a rapid regular wide QRS complex tachycardia (WCT). The tachycardia was spontaneously slow down during saline infusion. The atrial flutter with 2:1 AV conduction was demonstrated. The diagnosis of regular WCT was atrial flutter with 1:1 AV conduction. The precipitating cause could not be identified. The catheter ablation was successfully performed under EnSite Precision Cardiac Mapping System. The atrial flutter was suddenly terminated during catheter ablation along cavotricuspid isthmus. The patient remained sinus rhythm after eight months. Conclusion: The present case was an unusual case of atrial flutter with 1:1 AV conduction with unclear precipitating factors. Although some possible causes were demonstrated, clear precipitating causes in the present patient should be investigated in the future. Keywords: Atrial flutter with 1:1 AV conduction, Catheter ablation, Regular wide QRS complex tachycardia, Supraventricular tachycardia, Ventricular tachycardia

Recurrent Atrial Flutter Requiring Multiple Cardioversions in a Preterm Infant

We describe the first case of atrial flutter requiring multiple cardioversions in a preterm infant. Direct current cardioversion is one of the best-understood treatment options, with a first-time success rate higher than 96%. The electrocardiograms provided reveal a second run of atrial flutter occurring after successful cardioversion. (Level of Difficulty: Intermediate.)

A generalized eigenvalue solution to the flutter stability problem with true damping: The p-L method

An alternative solution to the flutter equation with a true damping representation is presented. The p-L method transforms the nonlinear eigenvalue problem into a linear generalized eigenvalue formulation by interpolating the nonlinear aerodynamic term with help of the Loewner and shifted-Loewner matrices, avoiding any kind of approximation. Subsequently an equivalent generalized state-space formulation in the time-domain is obtained, which stability can be determined by solving a standard generalized eigenvalue problem. The proposed method is shown to describe the aerodynamic term throughout the complex plane by analytic continuation of the interpolating rational functions over the imaginary axis, whereas expansions based on polynomial basis functions have a limited validity for excursions outside it. Further, the p-L method matches the generalized aeroelastic analysis method (GAAM) framework representing true damping but requiring only samples of the aerodynamic term along the imaginary axis, avoiding additional computations for non-zero damping. Unlike methods which solve the nonlinear eigenvalue problem whereby some roots of the flutter equation may be missed, the p-L method is able to find all roots at once. The method is applied to well-known flutter benchmark cases from the literature, namely, several two-dimensional flutter cases and the AGARD 445.6 wing aeroelastic benchmark case.

Algorithm for cavo-tricuspid isthmus flutter on surface ECGs: the ACTIONS study

ObjectiveCavo-tricuspid isthmus atrial flutter (CTI-AFL) is an important arrhythmia to recognise because there is a highly effective and relatively low-risk ablation strategy. However, clinical experience has demonstrated that providers often...

A general modal frequency-domain vortex lattice method for aeroelastic analyses

The generalized aerodynamic force (GAF) matrix is derived for the Unsteady Vortex Lattice Method (UVLM) without the assumption of out-of-plane dynamics. As a result, the approach naturally includes in-plane motion and forces unlike the doublet lattice method (DLM). The derived UVLM GAF is therefore applicable to industry-standard techniques for aeroelastic stability analyses, such as the p–k method. In this work, the fluid–structure interpolation is performed with radial basis functions for surface interpolation. The generalized aerodynamic forces computed with the UVLM are verified against the DLM from NASTRAN on a simple flat plate configuration. The ability of the UVLM to include steady loads is verified with a T-tail flutter case and the results confirm the importance of including steady loads for T-tail flutter analysis. The modal frequency domain VLM therefore provides the same level of efficiency and accuracy than the DLM, but without the restrictions and with the ability to handle complex geometries. It is therefore a viable replacement to the DLM.

An efficient coupled-mode flutter analysis method for turbomachinery

An efficient aeroelastic eigenvalue method based on time domain system identification has been developed to analyze coupled-mode flutter in turbomachinery. The aeroelastic stability problem is transformed into a generalized eigenvalue problem (GEP) by incorporating the aeroelastic equation and an aerodynamic modal force model. The aerodynamic modal force model correlates the generalized aerodynamic modal force with generalized motion variables by influence coefficient matrices which are calculated through a time domain system identification method. The aerodynamic damping ratios and the corresponding eigenfrequencies for all interblade phase angles (IBPA) can be obtained conveniently from a single time domain aerodynamic computation. The proposed method has been validated and demonstrated by presenting results for NASA Rotor 67 flutter cases in this paper.

Epicardial bridge via the coronary sinus musculatures revealed by ultra-high-definition mapping

Mapping and ablation of perimitral flutter, a macro-reentrant tachycardia, can be sometimes challenging. We describe a case of perimitral atrial flutter following the pulmonary vein isolation in which mitral isthmus ablation failed to terminate the arrhythmia due to epicardial-endocardial breakthrough via the muscle fibers of coronary sinus. Ultra-high-definition mapping system was utilized to locate the epicardial bridge, and spot ablation of the lesion subsequently terminated the arrhythmia.

RECURRENT ATRIAL FLUTTER IN A 37 WEEK GESTATION FEMALE NEONATE

Though rare, atrial flutter is the second most common type of arrhythmia that affects fetuses and newborns. Most cases of neonatal flutter can be converted to sinus rhythm via electrical cardioversion or medical management. A 37 + 5 week gestation neonate presented on the first day of life with

Short- and mid-term results of thoracoscopic atrial fibrillation ablation

Aim. Evaluation of short- and mid-term (up to one year) results of aт atrial fibrillation thoracoscopic radiofrequency ablation (TRFA) combined with left atrial appendage resection.Methods. 10 patients with persistent AF were included in the study. In 5 cases surgical ablation was performed as the primary intervention and in 5 cases surgery were preceded by two unsuccessful catheter procedures. Age of the patients was 54.4 (41; 63) years, duration of arrhythmic anamnesis – 5.6 (4.8; 6.8) years, anteroposterior size of the left atrium – 4.7 (45; 51 mm), LV ejection fraction – 63 (58; 68) %. TRFA included an isolation of right and left pulmonary veins, ablation lines along the roof and base of posterior wall of the left atrium, left atrial appendage resection.Results. In all cases of TRFA exit-block from the pulmonary veins was achieved. Among 10 procedures, a stable sinus rhythm was documented in 6 patients. In the remaining 4 patients AF was observed only in one case, and the other three demonstrated atypical atrial flutter, that given us a reason to repeat catheter procedures. In three cases of left atrial flutter, catheter ablation led to sinus rhythm restoration, and in case of AF and total sclerosis of left atrium a decision to refuse RF ablation was made. Complications were presented by a single case of bilateral phrenic nerve palsy, which required plication of the diaphragm, and two spontaneously resolved pulmonary atelectasis.Conclusion. The efficacy of atrial fibrillation thoracoscopic radiofrequency ablation during the follow-up period of one year was 90% regarding selective hybrid approach (thoracoscopic + catheter procedure). Procedure safety of TRFA was much lower than that of catheter ablation: the total number of small and big complications was 30%.