[Transvenous lead extraction at the University of Szeged: 10-year experience]

Bevezetés: A cardialis implantálható elektromos eszközökhöz kapcsolódó egyes komplikációk időnként részleges vagy teljes rendszereltávolítást, azaz transzvénás elektróda extrakciót igényelnek. A beavatkozások komplexitására és kimenetelére vonatkozó megfigyelések nemzetközi regiszterekből származnak, a kezelt betegcsoportok jellemzői azonban jelentős eltéréseket mutatnak. Célkitűzés: Az intézetünkben 2012 óta szisztematikusan működő extrakciós program eredményeinek összefoglalása és nemzetközi adatokkal való összehasonlítása. Módszerek: Retrospektív módon elemeztük a 2012 és 2022 között extrakcióban részesült betegek klinikai jellemzőit, a beavatkozások indikációit, technikáit és kimenetelét, összevetve ezeket a legnagyobb átfogó európai regiszter (ELECTRa) adataival. Vizsgáltuk továbbá a sikerarányt a „lépcsőzetes eszközbevetés” különböző szintjein. Eredmények: A vizsgálatba 200 beteget (65 ± 14,3 év, 74,5% férfi) vontunk be. Az extrakció indikációja dominálóan infekció volt, melynek aránya jóval meghaladta az ELECTRa-ban közöltet (87,5% vs. 52,8%, p<0,001). Az elektródák implantációs ideje szintén magasabb tendenciát mutatott tanulmányunkban (7,8 ± 6,2 vs. 6,4 ± 5,4 év), továbbá a passzív fixációs elektródák száma is szignifikánsan nagyobbnak bizonyult (62,2% vs. 46,6%, p<0,001). Betegeink egyötöde előzőleg már átesett egy sikertelen extrakciós kísérleten. A beavatkozások alatt nagyobb arányban volt szükség „locking styletek” (81,9% vs. 71,1%, p<0,001) és aktív extrakciós hüvelyek (71,8% vs. 27,1%, p<0,001) használatára. Major komplikáció 4,5%-ban, beavatkozáshoz köthető halál 4 esetben (2%) fordult elő. Procedurális sikert 88,2%-ban értünk el, mely alacsonyabbnak bizonyult az ELECTRa-ban közölt 95,7%-hoz képest. A lépcsőzetes eszközbevetés vizsgálata során a kumulatív klinikai sikerarány 24,8% volt „locki-ng stylettel” végzett húzással, 74,2% a primer aktív hüvellyel, 91,3% magas szintű extrakciós technikákkal (módozatváltás, femoralis extrakció), valamint 96,6%-ban nem sürgősségi szívsebészeti extrakcióval. Megbeszélés és következtetés: A Szegedi Tudományegyetem Elektrofiziológiai Részlegén sikeres, korszerű technikákon alapuló elektróda extrakciós program épült fel az elmúlt 10 évben. A kezelt betegek rizikóstatusa, valamint a beavatkozások komplexitása jóval meghaladja a nemzetközi regiszterek ilyen irányú jellemzőit. Az optimális sikerarány érdekében elengedhetetlen a különböző extrakciós technikák elérhetősége és az azokban való jártasság, valamint az implantálócentrumokkal folytatott szoros oktatási és referálási együttműködés. Orv Hetil. 2023; 164(49): 1954–1964.

Phenogrouping and risk stratification of patients undergoing cardiac resynchronization therapy upgrade using topological data analysis

Choosing the optimal device during cardiac resynchronization therapy (CRT) upgrade can be challenging. Therefore, we sought to provide a solution for identifying patients in whom upgrading to a CRT-defibrillator (CRT-D) is associated with better long-term survival than upgrading to a CRT-pacemaker (CRT-P). To this end, we first applied topological data analysis to create a patient similarity network using 16 clinical features of 326 patients without prior ventricular arrhythmias who underwent CRT upgrade. Then, in the generated circular network, we delineated three phenogroups exhibiting significant differences in clinical characteristics and risk of all-cause mortality. Importantly, only in the high-risk phenogroup was upgrading to a CRT-D associated with better survival than upgrading to a CRT-P (hazard ratio: 0.454 (0.228-0.907), p = 0.025). Finally, we assigned each patient to one of the three phenogroups based on their location in the network and used this labeled data to train multi-class classifiers to enable the risk stratification of new patients. During internal validation, an ensemble of 5 multi-layer perceptrons exhibited the best performance with a balanced accuracy of 0.898 (0.854-0.942) and a micro-averaged area under the receiver operating characteristic curve of 0.983 (0.980-0.986). To allow further validation, we made the proposed model publicly available ( https://github.com/tokmarton/crt-upgrade-risk-stratification ).

Baseline clinical characteristics of heart failure patients with reduced ejection fraction enrolled in the BUDAPEST-CRT Upgrade trial

AIMS

The BUDAPEST-CRT Upgrade study is the first prospective, randomized, multicentre clinical trial investigating the outcomes after cardiac resynchronization therapy (CRT) upgrade in heart failure (HF) patients with intermittent or permanent right ventricular (RV) pacing with wide paced QRS. This report describes the baseline clinical characteristics of the enrolled patients and compares them to cohorts from previous milestone CRT studies.

METHODS AND RESULTS

This international multicentre randomized controlled trial investigates 360 patients having a pacemaker (PM) or implantable cardioverter defibrillator (ICD) device for at least 6 months prior to enrolment, reduced left ventricular ejection fraction (LVEF ≤35%), HF symptoms (New York Heart Association [NYHA] functional class II-IVa), wide paced QRS (&gt;150 ms), and ≥20% of RV pacing burden without having a native left bundle branch block. At enrolment, the mean age of the patients was 73 ± 8 years; 89% were male, 97% were in NYHA class II/III functional class, and 56% had atrial fibrillation. Enrolled patients predominantly had conventional PM devices, with a mean RV pacing burden of 86%. Thus, this is a patient cohort with advanced HF, low baseline LVEF (25 ± 7%), high N-terminal pro-B-type natriuretic peptide (NT-proBNP) levels (2231 pg/ml [25th-75th percentile 1254-4309 pg/ml]), and frequent HF hospitalizations during the preceding 12 months (50%).

CONCLUSION

When compared with prior CRT trial cohorts, the BUDAPEST-CRT Upgrade study includes older patients with a strong male predominance and a high burden of atrial fibrillation and other comorbidities. Moreover, this cohort represents an advanced HF population with low LVEF, high NT-proBNP, and frequent previous HF events.

CLINICAL TRIAL REGISTRATION

ClinicalTrials.gov NCT02270840.

Atrial Remodeling in Atrial Fibrillation. Comorbidities and Markers of Disease Progression Predict Catheter Ablation Outcome

Atrial fibrillation is the most common supraventricular arrhythmia affecting an increasing proportion of the population in which mainstream therapy, i.e. catheter ablation, provides freedom from arrhythmia in only a limited number of patients. Understanding the mechanism is key in order to find more effective therapies and to improve patient selection. In this review, the structural and electrophysiological changes of the atrial musculature that constitute atrial remodeling in atrial fibrillaton and how risk factors and markers of disease progression can predict catheter ablation outcome will be discussed in detail.

European Heart Rhythm Association (EHRA) international consensus document on how to prevent, diagnose, and treat cardiac implantable electronic device infections-endorsed by the Heart Rhythm Society (HRS), the Asia Pacific Heart Rhythm Society (APHRS), the Latin American Heart Rhythm Society (LAHRS), International Society for Cardiovascular Infectious Diseases (ISCVID), and the European Society of Clinical Microbiology and Infectious Diseases (ESCMID) in collaboration with the European Association for Cardio-Thoracic Surgery (EACTS)

Pacemakers, implantable cardiac defibrillators, and cardiac resynchronization therapy devices are potentially lifesaving treatments for a number of cardiac conditions but are not without risk. Most concerning is the risk of a cardiac implantable electronic device (CIED) infection, which is associated with significant morbidity, increased hospitalizations, reduced survival, and increased health care costs. Recommended preventive strategies such as administration of intravenous antibiotics before implantation are well-recognized. Uncertainties have remained about the role of various preventive, diagnostic, and treatment measures such as skin antiseptics, pocket antibiotic solutions, antibacterial envelopes, prolonged antibiotics post-implantation, and others. When compared with previous guidelines or consensus statements, the present consensus document gives guidance on the use of novel device alternatives, novel oral anticoagulants, antibacterial envelopes, prolonged antibiotics post-implantation, as well as definitions on minimum quality requirements for centres and operators and volumes. The recognition that an international consensus document focused on management of CIED infections is lacking, the dissemination of results from new important randomized trials focusing on prevention of CIED infections, and observed divergences in managing device-related infections as found in an European Heart Rhythm Association worldwide survey, provided a strong incentive for a Novel 2019 International State-of-the-art Consensus document on risk assessment, prevention, diagnosis, and treatment of CIED infections.

Limitations of ventricular pacing maneuvers to differentiate orthodromic reciprocating tachycardia from atrioventricular nodal reentry tachycardia

PURPOSE

Various ventricular pacing maneuvers have been developed to differentiate orthodromic reciprocating tachycardia (ORT) from atrioventricular nodal reentry tachycardia (AVNRT). We aimed to evaluate the diagnostic value of ventricular pacing maneuvers in patients undergoing catheter ablation for AVNRT/ORT.

METHODS

Sixty patients with supraventricular tachycardia (SVT) undergoing invasive EP study were included (ORT: 31, typical AVNRT: 18, atypical AVNRT: 11). Ventricular overdrive pacing (VOP) and resetting by premature ventricular stimulation (PVS) during SVT were analyzed by 3 independent observers blinded to the ultimate diagnosis. We determined intraclass correlation coefficient (ICC) for interobserver agreement and the diagnostic accuracy of consensual results.

RESULTS

Although specificity of all parameters was high (96-100%) for ORT, semi-quantitative parameters of VOP (requiring the recognition of specific ECG patterns) had lower interobserver reliability (ICC: 0.32-0.66) and sensitivity (16.1-77.4%). In contrast, most quantitative measurements of VOP and PVS showed good reproducibility (ICC: 0.93-0.95) and sensitivity (74.2-89.3%), but post-pacing interval after VOP needed correction with AV nodal conduction slowing. False negative results for diagnosing ORT were more common with left free wall vs. right free wall or septal, and slowly vs. fast-conducting septal APs. False positivity was only seen with a bystander, concealed nodo-fascicular/nodo-ventricular (NF/NV) AP in a case of AVNRT.

CONCLUSIONS

No single maneuver is 100% sensitive for ORT. Semi-quantitative features have limited reproducibility and all parameters can be misleading in the case of rate-dependent delay during VOP/PVS, ORT circuits remote from the pacing site, or a bystander, concealed NF/NV AP.

Ultrasound guidance for femoral venous access in electrophysiology procedures-systematic review and meta-analysis

PURPOSE

The most common complications of electrophysiology (EP) procedures are related to vascular access. Our study aims to conduct a meta-analysis comparing ultrasound (US)-guided vs. palpation-based technique for femoral venous access in EP procedures.

METHODS

Electronic databases were searched and systematically reviewed for studies comparing femoral vein puncture with/without US in EP procedures. The primary outcome was the rate of major vascular complications; secondary outcomes were minor vascular complications, inadvertent artery puncture, postprocedural groin pain, and puncture time. Predefined subgroup analysis was conducted separately for patients undergoing pulmonary vein isolation procedure (PVI). A random-effects model was used to derive risk ratios (RR) with 95% confidence interval (CI).

RESULTS

Nine studies involving 8232 patients met our inclusion criteria. Compared with the standard technique, the use of US reduced major vascular complications (from 2.01 to 0.71%, p < 0.0001). The rate of minor vascular complications (RR = 0.30, 95% CI, 0.14-0.62, p = 0.001) and inadvertent artery puncture were lower with US-guided puncture (RR = 0.31, 95% CI, 0.17-0.58, p = 0.0003). Puncture time was shorter (mean difference = - 92.1 s, 95% CI, - 142.12 - - 42.07 s, p = 0.0003) and postprocedural groin pain was less frequent (RR = 0.57, 95% CI, 0.41-0.79, p = 0.0008) in the US group. Subgroup analysis of patients undergoing PVI also showed significant reduction of major vascular complications (RR = 0.27, 95% CI, 0.12-0.64, p = 0.003) and inadvertent artery puncture (RR = 0.35, 95% CI, 0.21-0.59, p < 0.0001).

CONCLUSION

Real-time US-guidance of femoral vein puncture in EP procedures is beneficial: it reduces major and minor vascular complications, inadvertent artery puncture, postprocedural groin pain, and puncture time.

18F-fluoro-dezoxi-glükóz pozitronemissziós tomográfia/komputertomográfia (18F-FDG-PET/CT) képalkotás a kardiológiában

Abstract:

Over the past decades, 18F-FDG-PET/CT imaging has been recognized as an indispensable tool in the diagnosis, staging and treatment monitoring of cancer. This modern imaging technique combining functional and morphologic information has approved indications not only in oncology but in clinical cardiology as well. In the current review we discuss the specific requirements of patient preparation and image acquisition protocol for cardiac 18F-FDG-PET/CT. We review the literature in some cases highlighted by our own examinations of well-known “gold standard” viability and onco-cardiology examinations while placing special emphasis on inflammatory disorders involving the heart. This relatively newer class of indications includes prosthetic valve endocarditis, cardiac implantable device infection, myocardial inflammation of varying origin such as sarcoidosis where 18F-FDG-PET/CT appears to be particularly useful in the differential diagnosis of cases where standard investigation is non-diagnostic or equivocal. Orv Hetil. 2019; 160(26): 1015–1024.

A jobb pitvari fülcse echokardiográfiás vizsgálata és annak klinikai jelentősége

Abstract:

In case of atrial fibrillation, there is a higher risk of thrombus formation, which could affect the right heart as well. Visualization of the right atrial appendage is difficult; the aim of the present review was to demonstrate the role of routine echocardiographic techniques and to show related clinical data. Orv Hetil. 2019; 160(12): 443–447.

Isolated left atrial posterior wall tachycardia

A case of macroreentry tachycardia of the isolated posterior left atrium is presented after surgical and subsequent catheter ablation.

A bal pitvari fülcse echokardiográfiás vizsgálata – transoesophagealis, transthoracalis és intracardialis lehetőségek

Abstract:

Left atrial appendage is a cardiac chamber in variable shapes and sizes. Its condition is associated with atrial arrhytmias and the presence of a thrombus. Due to its difficult visualisation, the present review aimed to demonstrate the role of different echocardiographic methods in its assessment. Orv Hetil. 2018; 159(9): 335–345.

Primary cardiac angiosarcoma: A case report

Cardiac angiosarcomas are the most common primary malignant cardiac tumors in adults. The diagnosis is often delayed due to nonspecific clinical symptoms at presentation. The cornerstones of diagnosis are echocardiography and the histological evaluation of the cardiac biopsy. The knowledge on the treatment is limited; the outcomes of chemotherapy, radiotherapy, complete surgical removal, and heart transplantation are controversial. We report a 38-year-old woman with a primary heart tumor which infiltrated the right atrial wall and the pericardium and caused pericardial effusion. Angiosarcoma was verified histologically. The surgical excision could not be radical, and the patient died 3 months from diagnosis.

Comparison of the effects of IK,ACh, IKr, and INa block in conscious dogs with atrial fibrillation and on action potentials in remodeled atrial trabeculae

Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia and a major cause of morbidity and mortality. Traditional antiarrhythmic agents used for restoration of sinus rhythm have limited efficacy in long-term AF and they may possess ventricular proarrhythmic adverse effects, especially in patients with structural heart disease. The acetylcholine receptor-activated potassium channel (I_K,ACh) represents an atrial selective target for future AF management. We investigated the effects of the I_K,ACh blocker tertiapin-Q (TQ), a derivative of the honeybee toxin tertiapin, on chronic atrial tachypacing-induced AF in conscious dogs, without the influence of anesthetics that modulate a number of cardiac ion channels. Action potentials (APs) were recorded from right atrial trabeculae isolated from dogs with AF. TQ significantly and dose-dependently reduced AF incidence and AF episode duration, prolonged atrial effective refractory period, and prolonged AP duration. The reference drugs propafenone and dofetilide, both used in the clinical management of AF, exerted similar effects against AF in vivo. Dofetilide prolonged atrial AP duration, whereas propafenone increased atrial conduction time. TQ and propafenone did not affect the QT interval, whereas dofetilide prolonged the QT interval. Our results show that inhibition of I_K,ACh may represent a novel, atrial-specific target for the management of AF in chronic AF.

Should the Aortic Root Be the Preferred Route for Ablation of Focal Atrial Tachycardia Around the AV Node?: Support From Intracardiac Echocardiography

OBJECTIVES

The purpose of this study was to determine the optimal approach to focal atrial tachycardia originating from around the atrioventricular node.

BACKGROUND

Focal atrial tachycardia (FAT) demonstrating earliest activation around the atrioventricular (AV) node during right atrial (RA) mapping has been eliminated by ablation at the RA para-Hisian region, from the left atrium (LA) or the noncoronary aortic cusp (NCC). However the optimal approach has not been determined.

METHODS

We conducted a retrospective analysis of a consecutive series of 148 patients undergoing catheter ablation for FAT between 2006 and 2014 in our institution.

RESULTS

Earliest activation was recorded in the peri-AV nodal region during RA mapping in 34 patients (23%). Of these, 7 patients (20.5%) had successful ablation at the RA septum, using either radiofrequency (n = 4) or cryoenergy (n = 3). Seven FATs (20.5%) were ablated from the LA at the region of the aortomitral continuity, and 20 patients (59%) had successful ablation in the NCC, including 1 patient with a recurrence after a temporarily successful cryoablation from the RA. The proportion of the 3 approaches in this series showed a significant temporal evolution and overall frequency favoring ablation in the NCC (p = 0.011 for time trend and 0.013 for actual vs. expected frequencies). Intracardiac echocardiography proved superior catheter stability with the NCC approach. There were 2 cases of atrioventricular block and 1 recurrence after RA ablation versus no complications or recurrent FAT with NCC and LA approaches.

CONCLUSIONS

Most peri-AV nodal FATs can be safely and effectively ablated from the NCC. The strategy of preferential NCC approach avoids RA para-Hisian ablation with the accompanying risk of AV block.

Very Long-Term Results Of Atrial Fibrillation Ablation Confirm That This Therapy Is Really Effective

Catheter ablation -in general- is a highly effective and "curative" intervention for a broad spectrum of supraventricular and ventricular arrhythmias. After a successful procedure eliminating a simple arrhythmia substrate, the recurrence rate is low and the short term success correlates well with the long term freedom from the arrhythmia.

Atrial tachycardias following atrial fibrillation ablation

One of the most important proarrhythmic complications after left atrial (LA) ablation is regular atrial tachycardia (AT) or flutter. Those tachycardias that occur after atrial fibrillation (AF) ablation can cause even more severe symptoms than those from the original arrhythmia prior to the index ablation procedure since they are often incessant and associated with rapid ventricular response. Depending on the method and extent of LA ablation and on the electrophysiological properties of underlying LA substrate, the reported incidence of late ATs is variable. To establish the exact mechanism of these tachycardias can be difficult and controversial but correlates with the ablation technique and in the vast majority of cases the mechanism is reentry related to gaps in prior ablation lines. When tachycardias occur, conservative therapy usually is not effective, radiofrequency ablation procedure is mostly successful, but can be challenging, and requires a complex approach.

Three-dimensional speckle tracking echocardiography-derived left atrial strain parameters are reduced in patients with atrial fibrillation (results from the MAGYAR-path study)

OBJECTIVE

Three-dimensional (3D) speckle tracking echocardiography (3DSTE) is a novel imaging modality for assessing cardiac function. We aimed to analyze left atrial (LA) function using 3DSTE in patients with atrial fibrillation (AF).

METHODS

3DSTE was performed in 20 patients prior to their pulmonary vein isolation for AF. Every patient underwent a complete two-dimensional echocardiographic study at the same time. 3DSTE-derived circumferential (CS), longitudinal (LS), radial (RS), 3D (3DS), and area strain (AS) values were measured in the basal (b), mid (m), and superior (s) regions of the LA. 3DSTE-defined maximal (LAmax ) and minimal LA volumes (LAmin ) and LA total emptying fraction were calculated automatically. Eleven randomly selected age- and gender-matched healthy volunteers served as controls.

RESULTS

Patients with AF had significantly larger LAmax and LAmin and reduced LS, RS and CS.3DS and AS were significantly lower throughout the LA in cases with AF (3DS-b, -m, -s [AF patients vs. controls]: -18 ± 8% vs. -29 ± 8%, P = 0.001; -14 ± 6% vs. -22 ± 7%, P = 0.002; -10 ± 7% vs. -20 ± 9%, P = 0.002; AS-b, -m, -s [AF patients vs. controls]: 35 ± 15% vs. 52 ± 13%, P = 0.004; 50 ± 21% vs. 72 ± 19%, P = 0.009; 31 ± 21% vs. 65 ± 27%, P < 0.0001, respectively).

CONCLUSIONS

3DSTE-derived "uni-dimensional" LS, RS, CS, as well as novel strain parameters (3DS, AS) are significantly reduced in patients with AF compared to matched controls. 3DS and AS might be new strain parameters providing further insights into the alterations of LA function in patients developing AF.

Role of triggering pulmonary veins in the maintenance of sustained paroxysmal atrial fibrillation

BACKGROUND

Triggers from thoracic veins have been implicated not only in the initiation, but also in the perpetuation of paroxysmal atrial fibrillation (PAF). To investigate their role we studied the distribution and stability of dominant frequencies (DFs) during PAF and the response to isolation of the triggering pulmonary vein (PV).

METHODS AND RESULTS

Triggering structures inducing PAF were identified during isoproterenol challenge in 26 patients (15 males, 55 ± 8.5 years). During sustained PAF, sequential recordings were made with a decapolar circular mapping catheter from each PV and the left atrial posterior wall (LAPW), together with coronary sinus (CS) and right atrium (RA) recordings. DF was determined using fast Fourier transformation. Recordings were repeated after ≥15 minutes of PAF. Radiofrequency ablation was directed first at the triggering PVs. PAF initiated from the PVs in 24 patients and from RA in two. There was a significant frequency gradient from the triggering structure to the PVs, CS, LAPW, and RA (P < 0.0001). During the second recording, DF decreased at all sites (P < 0.02), but the frequency gradient remained unchanged. Despite isolation of the triggering PV, PAF continued in 53% of patients, although DF measured in the CS was lower. AF termination occurred with contralateral PV isolation in half of the remaining patients and further AF slowing was noted in the rest.

CONCLUSIONS

Triggering structures harbor the fastest activity during sustained PAF pointing to their leading role in arrhythmia perpetuation. However, nontriggering PVs also seem to contribute to PAF maintenance.

Surgical technique and the mechanism of atrial tachycardia late after open heart surgery

INTRODUCTION

Diverse atrial tachycardias (ATs) can develop after open heart surgery. The aim of our study was to examine the determinants of the mechanism of postoperative AT.

METHODS AND RESULTS

One hundred patients with AT occurring at least 3 months after open heart surgery were studied. Patients were grouped according to the atrial incision applied at the time of surgery. During 127 electrophysiology procedures, 151 ATs were studied. Eighty-eight patients had cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL), 49 patients had at least one non-CTI-dependent AFL and 11 patients had focal AT. While CTI-dependent AFL was equally prevalent across groups, the finding of a non-CTI-dependent AFL was progressively more common as more extensive atriotomy was applied (p < 0.001). Among patients who had right atrial (RA) operations, RA incisional tachycardia was the most common non-CTI-dependent circuit, while the finding of perimitral or left atrial (LA) roof-dependent AFL was associated with LA atriotomy (p = 0.002 and p = 0.041, respectively). After adjustment for possible confounders, surgical group remained independent predictor of non-CTI-dependent AFLs (p < 0.001). No predictor was identified for focal AT, which originated from typical predilection sites and in 36% from the vicinity of surgical scar. Radiofrequency ablation was highly effective for all ATs, but the recurrence rate of AFL and atrial fibrillation was high at 22% and 27%, respectively, during 19 ± 15 months of follow-up.

CONCLUSION

While CTI-dependent AFL is the most common AT late after open heart surgery, atypical AFL becomes progressively more common with more extensive atriotomy. Right atrial incisional tachycardia is the dominant non-CTI-dependent AFL after opening of the RA, while a perimitral or roof-dependent LA circuit can be expected after LA operations.

Coexistent right- and left-sided slow pathways participating in distinct AV nodal reentrant tachycardias

We report a patient with two distinct atrioventricular (AV) nodal slow pathways, participating in two different AV nodal reentrant tachycardias--one eliminated from the right, the other only after ablation on the left side of the posterior septum. The case provides support for the concept of the posterior AV nodal extensions--a biatrial structure in most hearts--representing the anatomic basis of slow pathway conduction.

Ablation of posteroseptal and left posterior accessory pathways guided by left atrium-coronary sinus musculature activation sequence

INTRODUCTION

While some posteroseptal and left posterior accessory pathways (APs) can be ablated on the tricuspid annulus or within the coronary venous system, others require a left-sided approach. "Fragmented" or double potentials are frequently recorded in the coronary sinus (CS), with a smaller, blunt component from left atrial (LA) myocardium, and a larger, sharp signal from the CS musculature.

METHODS AND RESULTS

Forty patients with posteroseptal or left posterior AP were included. The LA-CS activation sequence was determined at the earliest site during retrograde AP conduction. Eleven APs (27.5%) were ablated on the tricuspid annulus (right endocardial), 9 (22.5%) inside the coronary venous system (epicardial), and 20 (50%) on the mitral annulus (left endocardial). A "fragmented" or double "atrial" potential was recorded in all patients inside the CS at the earliest site during retrograde AP conduction. Sharp potential from the CS preceded the LA blunt component (sharp/blunt sequence) in all patients with an epicardial AP, and in 10 of 11 (91%) patients with a right endocardial AP. Therefore, 18 of 19 (95%) APs ablated by a right-sided approach produced this pattern. The reverse sequence (blunt/sharp) was recorded in 19 of 20 (95%) patients with a left endocardial AP.

CONCLUSION

During retrograde AP conduction, the sequence of LA-CS musculature activation-as deduced from analysis of electrograms recorded at the earliest site inside the CS-can differentiate posteroseptal and left posterior APs that require left heart catheterization from those that can be eliminated by a totally venous approach.

Unusual case of orthostatic tachycardia

Bevezetés: Az orthostasis intolerancia, az orthostaticus tachycardia gyakran jelez hypovolemiát, gyógyszermellékhatást vagy autonóm elégtelenséget. Az orthostasisszal provokálható tachyarrhythmia ritka jelenség, emelt fejvégű billenőasztal vizsgálatsorozatokban csak elvétve fordul elő. Célkitűzés: A szerzők egy olyan beteget mutatnak be, akinek AV-csomó reentry tachycardiás paroxysmusait függőleges testhelyzet provokálta. Módszer: Vagusmanőverekkel az anterográd lassú pálya vezetésének blokkolása révén sikeresen szüntették a tachycardiát. Eredmények: Figyelemre méltó, hogy a vagusmanőverek csak vízszintes testhelyzetben bizonyultak hatásosnak. Következtetés: Ez a megfigyelés felhívja a figyelmet a manőverek pontos kivitelezésének fontosságára.

[Wenckebach AV block, as part of vasovagal syncope]

Vasovagal syncope or common faint is the most frequent form of syncopes. With regard to the different involvement of the efferent mechanisms, several forms of the neurally mediated syncope syndromes are recognized. The authors present a case of mixed type vasovagal syncope, diagnosed by tilt table testing. The efferent mechanisms of syncope included Wenckebach type atrioventricular block due to increased vagal tone, and sympathetic withdrawal, reflected by sudden drop in the blood pressure. The significance and interrelationship of these factors are discussed.

Oxidative stress and antioxidant defense mechanism in glomerular diseases

The changes in red blood cell (RBC) lipid peroxidation [measured via the malonyl dialdehyde (MDA) concentration], reduced (GSH), and oxidized glutathione (GSSG) levels, hemoglobin (Hb) oxidation and antioxidant enzyme [catalase (Cat), glutathione peroxidase, and superoxide dismutase (SOD)] activities were studied in 45 pediatric patients with various glomerular diseases [minimal change nephrotic syndrome (MCNS) in relapse or in remission, lupus nephropathy (SLE), poststreptococcal glomerulonephritis (APSGN), IgA nephropathy (IGA gn)], and in 20 adult patients with IGA gn and also in 15 pediatric and 14 adult controls. The in vitro effects of hydrogen peroxide [acetyl phenylhydrazine (APH) test] on the GSH and Hb metabolisms were likewise investigated. There was an increased oxidative stress in MCNS with relapse, IGA gn, SLE gn, and APSGN, which could be detected in the GSH and Hb oxidation and in the lipid peroxidation on the peripheral RBC-s. The RBC SOD and Cat activities were significantly lower in all patients than in the controls. The RBC GSSG level was significantly elevated in all patients, with the exception of MCNS in remission. This stimulated a compensatory GSH production in MCNS with relapse and in IGA gn, but not in SLE or APSGN. The regeneration of GSH from GSSG was reduced in MCNS with relapse, SLE, and IGA gn, but not in APSGN. In remission, the GSH-GSSG redox system normalizes, but in vitro the APH test stimulates an intensive Hb oxidation. In conclusion, there is a correlation between the presence of active glomerular disease and the evidence of oxidative changes in the various parameters measured in peripheral RBCs.