Acute and Long-Term Scar Characterization of Venous Ethanol Ablation in the Left Ventricular Summit.

BACKGROUND: Venous ethanol ablation (VEA) can be effective for ventricular arrhythmias from the left ventricular summit (LVS); however, there are concerns about excessive ablation by VEA. OBJECTIVES: The purpose of this study was to delineate and quantify the location, extent, and evolution of ablated tissue after VEA as an intramural ablation technique in the LVS. METHODS: VEA was performed in 59 patients with LVS ventricular arrhythmias. Targeted intramural veins were selected by electrograms from a 2F octapolar catheter or by guide-wire unipolar signals. Median ethanol delivered was 4 mL (IQR: 4-7 mL). Ablated areas were estimated intraprocedurally as increased echogenicity on intracardiac echocardiography (ICE) and incorporated into 3-dimensional maps. In 44 patients, late gadolinium enhancement cardiac magnetic resonance (CMR) imaged VEA scar and its evolution. RESULTS: ICE-demonstrated increased intramural echogenicity (median volume of 2 mL; IQR: 1.7-4.3) at the targeted region of the 3-dimensional maps. Post-ethanol CMR showed intramural scar of 2.5 mL (IQR: 2.1-3.5 mL). Early (within 48 hours after VEA) CMR showed microvascular obstruction (MVO) in 30 of 31 patients. Follow-up CMR after a median of 51 (IQR: 41-170) days showed evolution of MVO to scar. ICE echogenicity and CMR scar volumes correlated with each other and with ethanol volume. Ventricular function and interventricular septum remained intact. CONCLUSIONS: VEA leads to intramural ablation that can be tracked intraprocedurally by ICE and creates regions of MVO that are chronically replaced by myocardial scar. VEA scar volume does not compromise septal integrity or ventricular function.

Dependence of the Atrioventricular Conduction Time on the Conduction through the Atrioventricular Node and His-Purkinje System.

The electrical depolarization of the heart passes through various structures of the cardiac conduction system, which modify its conduction to different extents. In this study, we investigated the relationship between the atrioventricular conduction time (AV interval) and its contributors, the atrioventricular node (AVN) and the His-Purkinje system (HPS), as represented by the AH and HV intervals, respectively. We also compared sex differences in these intervals and their relations. Resting intracardiac tracings lasting 5 min were obtained from 64 patients (33 women) during an invasive electrophysiological study. The aforementioned intervals were measured for all consecutive beats. The mean AH interval was 85.9 ms, HV 43.7 ms, and AV 129.6 ms. Men had longer AH (80.0 vs. 65.9 ms), HV (38.4 vs. 35.3 ms), and AV intervals (124.7 vs. 108.5 ms) than women. The AV intervals were linearly correlated with AH intervals in all patients (r2 = 0.65). No significant correlation was found between AV and HV intervals in all patients (r2 = 0.05). There were no sex differences in these associations. Our results suggest that the atrioventricular conduction time depends mainly on the conduction through the AVN and less on the HPS. These relations are similar in both sexes, although men had longer conduction times through the AVN, HPS, and total atrioventricular conduction time.

Intramural Venous Ethanol Infusion for Refractory Ventricular Arrhythmias: Outcomes of a Multicenter Experience.

OBJECTIVES: The aim of this study was to assess the long-term efficacy and outcomes of retrograde venous ethanol ablation in treating ventricular arrhythmias (VAs). BACKGROUND: Retrograde coronary venous ethanol ablation (RCVEA) can be effective for radiofrequency ablation (RFA)-refractory VAs, particularly those arising in the LV summit (LVS). METHODS: Patients with drug and RFA-refractory VAs were considered for RCVEA after RF failure attempts. Intramural coronary veins (tributaries of the great cardiac, anterior interventricular, lateral cardiac, posterolateral, and middle cardiac) were mapped using an angioplasty wire. Ethanol infusion was delivered in veins with appropriate signals. RESULTS: Of 63 patients (age 63 ± 14 years; 60% men) with VAs (71% extrasystole, 29% ventricular tachycardia, 76% LVS origin), RCVEA was performed in 56 patients who had suitable vein branches. These were defined as those amenable to cannulation and with intramural signals that preceded those mapped in the epicardium or endocardium and had better matching pace maps or entrainment responses. Seven patients had no suitable veins and underwent RFA. In 38 of 56 (68%) patients, the VAs were successfully terminated exclusively with ethanol infusion. In 17 of 56 (30%) patients, successful ablation was achieved using ethanol with adjunctive RFA in the vicinity of the infused vein due to acute recurrence or ethanol-induced change in VA morphology. Overall, isolated or adjuvant RCVEA was successful in 55 of 56 (98%) patients. At 1-year follow-up, 77% of patients were free of recurrent arrhythmias. Procedural complications included 2 venous dissections that led to pericardial effusions. CONCLUSIONS: RCVEA offers a significant long-term effective treatment for patients with drug and RF-refractory VAs.

Islets of heterogeneous myocardium within the scar in cardiac magnetic resonance predict ventricular tachycardia after myocardial infarction.

INTRODUCTION: We assessed findings in cardiac magnetic resonance (CMR) as predictors of ventricular tachycardia (VT) after myocardial infarction (MI), which could allow for more precise identification of patients at risk of sudden cardiac death. METHODS: Forty-eight patients after prior MI were enrolled and divided into two groups: with (n = 24) and without (n = 24) VT. VT was confirmed by electrophysiological study and exit site was estimated based on 12-lead electrocardiogram. All patients underwent CMR with late gadolinium enhancement. RESULTS: The examined groups did not differ significantly in clinical and demographical parameters (including LV ejection fraction). There was a significant difference in the infarct age between the VT and non-VT group (15.8 ± 8.4 vs 7.1 ± 6.7 years, respectively; P = .002), with the cut-off point at the level of 12 years. In the scar core, islets of heterogeneous myocardium were revealed. They were defined as areas of potentially viable myocardium within or adjacent to the core scar. The number of islets was the strongest independent predictor of VT (odds ratio [OR], 1.42; confidence interval [CI], 1.17-1.73), but total islet size and the largest islet area were also significantly higher in the VT group (OR, 1.04; CI, 1.02-1.07 and OR, 1.16; CI, 1.01-1.27, respectively). Myocardial segments with fibrosis forming 25%-75% of the ventricular wall were associated with a higher incidence of VT (7.5 ± 2.1 vs 5.7 ± 2.6; P = .014). Three-dimension CMR reconstruction confirmed good correlation of the location of the islets/channels with VT exit site during electroanatomical mapping in five cases. CONCLUSIONS: The identification and quantification of islets of heterogeneous myocardium within the scar might be useful for predicting VT in patients after MI.

Double atrial potentials in left-sided accessory pathways are associated with paroxysmal atrial fibrillation.

INTRODUCTION: Muscular connections between the coronary sinus (CS) and left atrium probably impact distribution of electrical activity. Double atrial potentials (DP) may be their presentation. The aim was to investigate the presence of DP in CS recordings during atrioventricular reentrant tachycardia (AVRT) and its contribution to the occurrence of paroxysmal atrial fibrillation (AF). METHODS: A group of 247 patients with accessory pathways (AP) were screened for DP. The patients with DP during AVRT were compared to those without DP. RESULTS: DP during AVRT were found only among the left-sided AP (AP-L). Patients with AP-L were divided into Group 1 (n  =  17) with DP during AVRT and Group 2 (n  =  108) without DP. Patients in Group 1 had higher incidence of AF in history (47.1% vs. 23.1%; P  =  0.0376), AF induced during electrophysiological (EP) study (70.6% vs. 25%; P  =  0.0002). Group 1 had higher heart rate (HR) during AVRT in the EP study (197.2 ± 27 vs. 175.1 ± 26.3 bpm; P  =  0.0019), but HR of clinical AVRT (208.5 ± 30.8 vs. 191.6 ± 27.8 bpm) was not significant different (P  =  ns). Additionally, electrical alternans of QRS amplitude during AVRT in the EP study was more frequent in Group 1 (52.9 vs. 20.4 %; P  =  0.0048). CONCLUSION: Patients with DP and AP-L were more prone to develop AF. The presence of DP was associated with faster AVRT rate. The direction of atrium depolarization during AVRT may be different in the presence of DP and probably plays a role in development of AF in this group of patients.

The Management of Supraventricular Tachyarrhythmias in Patients with Pulmonary Arterial Hypertension.

BACKGROUND: Atrial remodelling in pulmonary arterial hypertension (PAH) may lead to higher incidence of supraventricular arrhythmias (SVA). The purpose of this study was to evaluate the efficiency and safety of various methods for treatment of SVA in this group. METHODS: This was a single centre study. Forty-eight patients (33 women and 15 men) aged 19-77 years (median 49 years) were enrolled. There were 30 patients with idiopathic PAH, 10 had PAH associated with connective tissue disease, and eight with congenital heart disease. A retrospective analysis was performed to estimate the prevalence and type of supraventricular arrhythmias, as well as efficiency and safety of treatment methods. Mean follow-up period was 28.8±17.7 months. RESULTS: Supraventricular arrhythmias occurred in 17 patients (35%) and appeared to be atrial fibrillation, flutter or tachycardia. Supraventricular arrhythmias coexisted with elevated mean right atrial pressure in 75%. Four patients had more than one type of SVA. A flutter-like macro-reentrant form of atrial tachycardia dependent on cavo-tricuspid isthmus was found in four cases. The treatment of SVA included typical methods: antiarrhythmic drugs, direct current cardioversion (DCC), and radiofrequency (RF) ablation. All of the therapeutic methods were effective in managing acute arrhythmia. Three patients required re-ablation. Overall mortality: 14 patients (29%) in the whole study group, including six in SVA group (35%) and eight without SVA (26%). CONCLUSIONS: In patients with PAH DCC, pharmacological cardioversion and RF ablation can be applied safely and effectively. Flutter-like macro-reentrant atrial tachycardia dependent on cavo-tricuspid isthmus is observed in this group. It is more challenging, but possible, to successfully treat this arrhythmia with RF ablation.

Unresectable cardiac pseudoneoplasms causing ventricular tachycardia.

Cardiac pseudoneoplasms are rare and benign. According to World Health Organization, they are classified as tumor-like lesions. We report two patients with recurrent ventricular tachycardia (VT) in whom magnetic resonance imaging revealed a pathological mass occupying a large part of the left ventricle. The localization of both tumors precluded the possibility of resection; thus, only surgical biopsy was performed. After deducting the prospect of malignancy of the tumors, we treated both patients with amiodarone and implantation of a cardioverter-defibrillator [implanted cardioverter/defibrillator (ICD)]. VT is one of many probable symptoms indicating a tumor within the heart; therefore, treatment with an ICD should only be considered after a more thorough diagnosis.

Asymmetry of the variability of heart rate and conduction time between atria and ventricles.

BACKGROUND: Heart rate asymmetry is caused by an unequal contribution of heart rate decelerations and accelerations to heart rate variability. This study evaluates the asymmetric properties of the variability of the AA, HH, VV, AH and HV intervals. METHODS AND RESULTS: We recorded 50 1-min intracardiac ECG tracings from 10 patients (18-66 years old; 8 females) during a routine electrophysiological study. Standard descriptors of variance asymmetry were calculated for all intervals. Nonparametric tests were used for statistical comparisons. The prolongations of VV (P=0.0297), AH (P=0.0133) and HV (P=0.0004) intervals contributed significantly more than their shortenings to their short-term variance. The proportion of recordings with a larger contribution of prolongations than shortenings was significantly different from random for VV (0.66, P=0.0328), AH (0.68, P=0.0154) HV (0.74, P=0.0009). CONCLUSIONS: In addition to heart rate asymmetry (VV interval), the conduction from the atria, through the atrioventricular node, His-Purkinje system to ventricles shows asymmetric properties in 1-min tracings.

[Unusual epicardial location of ventricular ectopy in left ventricular outflow tract, cured with RF ablation from the great cardiac vein]. / Nietypowa, epikardialna lokalizacja dodatkowych skurczów komorowych z drogi odplywu lewej komory, leczona ablacja RF z obszaru zyly wielkiej serca.

The case report refers to a 54-year-old woman with a drug-refractory premature ventricular contractions (total number of ventricular ectopy: 40,851 beats/24 h) where an ectopy focus was localised in epicardial part of the left ventricular outflow tract. Successful radiofrequency ablation with the open-irrigated-tip catheter was performed at the site of earliest activation in the great cardiac vein.

[Unusual picture of pacemaker leads in patient after Senning procedure]. / Nietypowy uklad elektrod stymulatora u pacjenta po operacji Senninga.

We present a case of a 21-year-old man after Senning operation admitted to our hospital for transvenous implantation of a dual chamber pacemaker. The presence of persistent left superior vena cava enabled us to implant the desired dual chamber pacemaker. It is an extremely unusual situation when two pacemaker leads utilise two different routes to the heart: superior caval vein - atrial baffle - ventricle and persistent left superior caval vein - atrium.

[ST segment elevation typical for Brugada syndrome after intracoronary acetylocholine injection with retrosternal pain in history]. / Zmiany ST−T o typie zespolu Brugadów po podaniu dowiencowym acetylocholiny u mlodego mezczyzny z bólami w klatce piersiowej.

Chest pain is mainly linked with acute coronary syndrome, but sometimes it can be the only manifestation of ventricular tachycardia. We present a case of a young man who was diagnosed with Brugada syndrome after intracoronary acetylocholine injection, with negative test with flecanaide. First manifestation of a disease was a chest pain.

[Contribution of atrioventricular node inputs on orthodromic atrioventricular reentrant tachycardia cycle length]. / Wplyw wlasciwosci wezla przedsionkowo-komorowego na cykl ortodromowego czestoskurczu przedsionkowo-komorowego.

We describe a 21-year-old woman with a previous history of orthodromic AVRT and overt preexcitation. Electrophysiological study revealed the presence of a left-sided accessory pathway. During an orthodromic AVRT a spontaneous sudden change in heart rate (141 to 202 beats/min) without any change of the QRS morphology was noted due to a decrease in AH interval (from AH=227 ms to AH=100 ms). We explained this phenomenon as the sudden change of the inferior inputs to superior in the AV node.

["Benign" atrial arrhythmias exacerbated by physical activity as a cause of cardiomyopathy]. / "Lagodne" arytmie przedsionkowe nasilane wysilkiem przyczyna kardiomiopatii.

We describe a 39-year-old man with premature atrial contractions at rest, in whom tachycardia was exacerbated by exercise into long-lasting atrial tachycardia of 150 beats/min with changeable grade of AV conduction. The feeling of irregular heart beating was the only symptom of arrhythmia and was well tolerated for many years. However, the signs of tachycardia-mediated cardiomyopathy with heart failure developed over several years. Successful RF ablation of focal atrial tachycardia using the CARTO system was performed. After 5 months of follow-up the patient is free from arrhythmia with a significant improvement of the HF.

[Atrioventricular nodal tachycardia with left-sided slow pathway treated with RF ablation]. / Napadowy czestoskurcz wezlowy z lewostronnym szlakiem wolnym.

We present a case of 10-year-old boy with AVNRT. The tachycardia had prolonged RP interval (160 ms) and HA time (135 ms). The application at the rim of the coronary sinus resulted in accelerated junctional rhythm and retrograde block followed by transiently prolonged atrioventricular conduction. The mapping of the mitral annulus transeptally presented no 'slow potentials'. The electrode was then inserted retrogradely through the aorta and slow potentials were recorded on the septal aspect of the left atrium. Two RF applications at this site were successful. The patient was followed for three years without recurrence of arrhythmia.