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Introduction: There is a lack of studies in the literature directly investigating the relationship between atrial tachycardia (AT) and left atrial (LA)/left atrial appendage (LAA) thrombus, and current guidelines do not provide strong recommendations regarding the use of transesophageal echocardiography (TEE) before AT catheter ablation. This study aims to elucidate the relationship between AT and the presence of LA/LAA thrombus and contribute to the literature on the use of TEE before AT catheter ablation. Methods: This single‐center retrospective observational study screened patients who underwent TEE between February 10, 2019, and February 10, 2023. Patients were assigned to the AT patient and control groups. TEE was conducted to exclude thrombus in the AT ablation group. The control group included patients who underwent TEE for interatrial septum evaluation and had LA imaging during TEE but did not have atrial arrhythmia. To mitigate bias between the AT patient group and the control group, they were randomized 1:1 using propensity‐score matching (PSM). Following randomization, each group consisted of 49 patients. Results: All analyses were conducted after PSM. There were no statistically significant differences between the AT patient and control groups in terms of baseline clinical characteristics and echocardiographic features. Additionally, no significant differences were found between the blood viscosities calculated at low and high shear rates in both groups. The study revealed a significant difference between the two groups in the presence of LA spontaneous echo contrast (SEC) (24.5% in AT group vs 0% in Control group, p =.001), but not in the presence of thrombi (8.2% in AT group vs 0% in Control group, p =.117). Conclusion: Compared to the control group, the presence of SEC was significantly higher in the AT patient group. The increased frequency of SEC in AT patients suggests the hypothesis that AT may contribute to LA stasis. The routine use of TEE before AT catheter ablation remains controversial, despite the presence of LA thrombus and SEC in the AT patient group. The clinical assessment of thrombus presence before the procedure must be conducted on a patient‐specific basis. [ABSTRACT FROM AUTHOR]

The article presents a case study of a 38-year-old woman with recurrent palpitations and no structural heart disease, who presented with a documented wide QRS complex tachycardia (WCT) with negative precordial concordance. It discusses the differential diagnosis of the tachycardia mechanism and the management approach, including electrophysiologic study and radiofrequency ablation.

The article describes the case of a 67-year-old diabetic man with ischemic cardiomyopathy presented with a recurrent defibrillator shock. Topics discussed include medical history of the patient, importance of the introduction of premature ventricular complexes (PVC) during wide complex tachycardias (WCT), and ventriculoatrial (V-A0 responses of the tachycardia.

The article presents a case of a 58-year-old male experiencing recurrent episodes of paroxysmal palpitation to discuss the mechanism of a wide QRS tachycardia with short and long ventriculoatrial interval in the presence of atriofascicular (AF) accessory pathway (AP). Also cited are the patient's spontaneous sustained wide complex tachycardia (WCT) with left bundle branch block (LBBB) morphology, and the differential diagnosis of regular WCT like atrial flutter or atrial tachycardia (AT).

The article presents a case of a 29-year-old female with repeated paroxysms of palpitations due to rapid narrow QRS complex tachycardia (NCT) to discuss the dynamic changes in atrial activation sequence during supraventricular tachycardia and the mechanism of the tachycardia. Other topics include left atrial tachycardia (AT), premature ventricular complex (PVC), and atrioventricular nodal reentrant tachycardia (AVNRT).

The article presents a case study of a 75-year-old man with history of ischemic cardiomyopathy with an ejection fraction referring for ablation of recurrent ventricular tachycardia (VT). Topics include electroanatomic mapping of the endocardium revealing extensive dense scar extending from the base toward the apex along the inferior and lateral walls; and Decanav catheter recording a local V‐shaped diastolic activation pattern.

The article presents a case study of a 28-year-old woman undergoing an electrophysiology study (EPS). Topics include episodes of palpitations with documented narrow (NCT) and wide QRS complex tachycardia (WCT); and dissociation of HB potential from ongoing tachycardia favor AVNRT with BBB aberrancy.

The article presents a case study of a 38-year-old woman with recurrent episodes of tachycardia in the absence of structural heart disease and documented with narrow QRS complex tachycardia (NCT). Topics include first tachycardia diagnosed as typical atrioventricular (AV) nodal reentrant tachycardia (AVNRT) and the radiofrequency ablation of the slow pathway; and attributable to a retrograde atrial activation by the last ventricular stimulus in contrast to ventricular entrainment.

The article presents a case of a 21-year-old male who was rushed to a clinic due to regular palpitations and narrow complex tachycardia (NCT) and wide complex tachycardia (WCT) to discuss the mechanism of tachycardia and the transition from two WCT to narrow QRS tachychardia. Also cited are the observation of two WCTs with both right bundle branch block (RBBB) and left BBB (LBBB) in the patient, and the differential diagnosis of short RP NCT like atrial tachycardia (AT).

The article describes the case of a 20-year-old male with an implantable cardioverter-defibrillator (ICD) that had been implanted seven years ago due to recurrent and failed ablation for fascicular left ventricular tachycardia. Topics include results of electrophysiological study and differential diagnosis of narrow complex tachycardia (NCT) with ventriculoatrial (VA) dissociation or variable block to the atrium.

The article presents a case study of a 59-year-old man who had rapid palpitations and documented supraventricular tachycardia (SVT) unresponsive to metoprolol therapy. He was diagnosed with an accessory pathway (AP) conduction, with the pathway being a bystander, and as orthodromic tachycardia (ORT) with posteroseptal AP. Also noted is the possibility of resetting even if no change in subsequent cycle length is seen during tachycardia.

The article describes the case of a 52-year-old man presented with repeated paroxysms of palpitations resulting from a rapid narrow and wide QRS complex tachycardia. Highlights include decremental ventriculoatrial conduction shown by right ventricular pacing, the importance of recognizing a His bundle potential for the differentiation, and the termination response to a single atrial extra stimulus from the high right atrium at the time of his refractoriness.

The article present a case study of a 33-year old woman with regular palpitations and documented a shortRP narrowQRS complex tachycardia. Topics discussed include the retrograde conduction was decremental and concentric with the earliest activation site at the His bundle region; the presence of anterograde dual AV nodal pathways; and origin of atrial tachycardia (AT) from near the AV node.

The article presents a case study of a 34-year-old man with palpitations and a narrow QRS complex tachycardia. It states that atrial (AT) and atrioventricular reentrant (AVRT) tachycardias were excluded due to the majority presence of ventricular activations. Also noted is the elimination of tachycardia induction via the performance of a slow pathway modification.

A 32‐year‐old woman underwent radiofrequency catheter ablation of narrow QRS tachycardia that was terminated with intravenous adenosine. [ABSTRACT FROM AUTHOR]

The article describes the case of a 40-year-old female diagnosed with dual tachycardia with 1:2 tachycardia and atrioventricular (AV) nodal reentrant tachycardia with retrograde 1:2 response. Topics include twelve-lead electrocardiogram during sinus rhythm, the possibility of dual AV nodal pathways with simultaneous fast and slow conduction, and the relationship between the His potentials of the fast and slow pathways.

The article presents a case study of a 63-year-old man suffering from ischemic ventricular tachycardias (VTs) with recurrent implantable cardioverter-defibrillator (ICD) shocks despite the use of amiodarone, underwent endocardial VT ablation. Using an activation map, an isthmus was located and targeted in the middle of the anteroseptal area of the left ventricle.

The article presents a case study of a 28-year-old woman underwent radiofrequency catheter ablation of narrow QRS tachycardia (NQT) that was terminated with intravenous adenosine. Topics include the main differential diagnosis of an irregular arrhythmia is between the AV nodal reentrant tachycardia (AVNRT) and perinodal atrial tachycardia (AT); and spontaneous changes in the measured intracardiac intervals during tachycardia are useful in determining the mechanism of arrhythmia.

The article presents a case of a 22-year-old male with recurrent episodes of tachycardia who underwent an electrophysiological assessment that induced narrow complex tachycardia (NCT) to discuss the potential mechanism of the transient changes to his QRS morphology during NCT. Also cited are the differential diagnosis of NCT with V-A dissociation including atrioventricular nodel reentrant tachycardia (AVNRT) with block in the upper common pathway (UCP).

Background The autonomic nervous system (ANS) is a potentially potent modulator of the initiation and perpetuation of atrial fibrillation (AF), whereas the presence of AF can activate and alter the ANS. The catheter ablation of AF (AFCA) may cause the cardiac ANS dysfunction, whereas restoration of sinus rhythm or sympathovagal imbalance by AFCA can reverse this process. Our principal goal was to investigate the short-term effect of AFCA on ANS functions evaluated by noninvasive chronotropic (CI), resting heart rate (RHR), and heart rate recovery (HRR) indices. Method A total of 45 patients were enrolled with symptomatic, drug refractory paroxysmal AF undergoing first cryoballoon (CB) pulmonary vein antrum isolation (PVAI) with one 28-mm CB using single 3-minute freeze techniques without bonus applications. All patients underwent symptom-limited exercise treadmill testing to evaluate noninvasive parameters of ANS before PVAI. For those patients who remained in sinus rhythm, an additional exercise test was repeated after 1 and 3 months after discharge. Results The autonomic CI and RHR/HRR indices were impaired after PVAI and persisted post-PVAI 3 months. However, these parameters were not different in patients with and without recurrence. Conclusion This study demonstrated that the successful AFCA might concurrently impair the ANS parameters. The autonomic imbalance between the sympathetic and parasympathetic activity after AFCA could either become antiarrhythmic and/or proarrhythmic based on which of the two components was going to prevail after successful AFCA. The impaired ANS balance after PVAI might also be another hypothetical mechanism for AF recurrence particularly in the absence of PV reconnection. [ABSTRACT FROM AUTHOR]

Entrainment is an important tool for the diagnosis and location of reentry. The usefulness of this maneuver requires that, prior to cessation of ventricular pacing, the atrial rate accelerates to the ventricular pacing rate. Moreover, it is important to verify the continuation of the tachycardia following cessation of entrainment. The recognizing the last entrained atrial beat is utmost important to avoid erroneous A–A–V labeling. [ABSTRACT FROM AUTHOR]

In this study, the efficacy of creating cellular hydrogel coatings on warm tissue surfaces through the minimally invasive, sprayable delivery of thermoresponsive liquid solutions was investigated. Poly( N-isopropylacrylamide)-based (pNiPAAm) thermogelling macromers with or without addition of crosslinking polyamidoamine (PAMAM) macromers were synthesized and used to produce in situ forming thermally and chemically gelling hydrogel systems. The effect of solution and process parameters on hydrogel physical properties and morphology was evaluated and compared to poly(ethylene glycol) and injection controls. Smooth, fast, and conformal hydrogel coatings were obtained when pNiPAAm thermogelling macromers were sprayed with high PAMAM concentration at low pressure. Cellular hydrogel coatings were further fabricated by different spraying techniques: single-stream, layer-by-layer, and dual stream methods. The impact of spray technique, solution formulation, pressure, and spray solution viscosity on the viability of fibroblast and osteoblast cells encapsulated in hydrogels was elucidated. In particular, the early formation of chemically crosslinked micronetworks during bulk liquid flow was shown to significantly affect cell viability under turbulent conditions compared to injectable controls. The results demonstrated that sprayable, in situ forming hydrogels capable of delivering cell populations in a homogeneous therapeutic coating on diseased tissue surfaces offer promise as novel therapies for applications in regenerative medicine. © 2016 Wiley Periodicals, Inc. J Biomed Mater Res Part A: 104A: 2383-2393, 2016. [ABSTRACT FROM AUTHOR]

The termination of tachycardia may provide important clues toward the mechanism of the tachycardia and that close vigilance may clinch the diagnosis before proceeding to other pacing maneuvers. [ABSTRACT FROM AUTHOR]

ABSTRACT In this study, the effect of solvents on the morphology and conductivity of poly(3,4-ethylenedioxythiophene):poly(styrenesulfonate)(PEDOT:PSS) nanofibers is investigated. Conductive PEDOT:PSS nanofibers are electrospun by dissolving a fiber-forming polymer, polyvinyl alcohol, in an aqueous dispersion of PEDOT:PSS. The conductivity of PEDOT:PSS nanofibers is enhanced 15-fold by addition of DMSO and almost 30-fold by addition of ethylene glycol to the spinning dopes. This improvement is attributed to the change in the conformation of the PEDOT chains from the coiled benzoid to the extended coil quinoid structure as confirmed by Raman spectroscopy, X-ray diffraction, and differential scanning calorimetry. Scanning electron microscopy images show that less beady and more uniform fiber morphology could be obtained by incorporation of ethylene glycol in the spinning dopes. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci. 2014, 131, 40305. [ABSTRACT FROM AUTHOR]

The focus of this article is to develop a surface plasmon resonance (SPR) nanosensor to determine chloramphenicol (CAP) using the molecularly imprinted nanoparticles. The CAP imprinted nanoparticles were prepared by miniemulsion polymerization method. Then, the nanoparticles were attached onto the SPR nanosensor surface via temperature-controlled evaporation. Surface characterization studies were performed with atomic force microscopy and contact angle measurements. Kinetic studies were performed with CAP solutions in the concentration range of 0.155-6.192 n M. Florphenicol (FLP) and thiamphenicol (TAP) having similar chemical structures to the template (i.e., CAP) were chosen as competitors to determine selectivity of the nanoparticles. Selectivity constants were observed as 8.86 for CAP/TAP and 8.36 for CAP/FLP. The detection limit was calculated as 40 ng/kg honey sample. In the light of these results, it was emphasized that the SPR nanosensor is able to recognize CAP selectively and has a potential for real-time CAP detection in honey sample. © 2013 Wiley Periodicals, Inc. J. Appl. Polym. Sci., 2013 [ABSTRACT FROM AUTHOR]

The article describes the case of a 21-year-old woman who underwent radiofrequency catheter ablation of narrow QRS tachycardia that was terminated with intravenous adenosine. Highlights include the mechanisms of the unexpected ventriculoatrial block response to the parahisian pacing (PHP) maneuver, demonstration of a retrograde nodal activation pattern during PHP, and the administration of slow pathway ablation to eliminate atrioventricular nodal tachycardia from the patient.

Transseptal catheterization has become part of the interventional electrophysiologist׳s technical armamentarium since the development of left atrial catheter ablation and percutaneous technologies for treating mitral and aortic valve disease. Although frequently performed, the procedure׳s most feared complication is aortic root penetration. Focal atrial tachycardia has been described as the most common late sequela of surgical valve replacements. We present a complicated case involving the inadvertent delivery of an 8 French sheath across the noncoronary cusp during radiofrequency catheter ablation for left atrial tachycardia originating from the mitral annulus in a patient with prior mitral valve replacement. [ABSTRACT FROM AUTHOR]