Left and right atrial appendage functional features as predictors for voltage-defined left atrial remodelling in patients with long-standing persistent atrial fibrillation.

It was hypothesised that left atrial (LA) fibrosis identified by the presence of low-voltage areas (LVA) may influence the mechanical and electrical function of the left (LAA) and right (RAA) atrial appendage among the long-standing persistent atrial fibrillation (LSPAF) population. 140 consecutive patients underwent voltage mapping of LA with a multielectrode catheter following pulmonary vein isolation and restoration of sinus rhythm with cardioversion. Echocardiography determined LAA peak outflow and inflow velocities and intracardiac catheter-based mean LAA and RAA AF cycle length (AFCL) were obtained during AF before ablation. The impact of flow velocities and AFCL on the prevalence and location of LVA was further evaluated. LVA were detected in 54% of the patients. 14% of the patients presented severe global LVA burden > 20% of the total LA surface area. 29% of the patients presented a disseminated pattern of remodelling as 3 out of 5 LA segments were affected. LAA AFCL, RAA AFCL, LAA flow velocities did not predict the absolute presence of LVA. However LAA AFCL > 155 ms predicted disseminated LVA pattern and LAA AFCL > 165 ms severe LVA incidence. LAA AFCL > 155 ms was predictive for existence of LVA within antero-septal LA segments whilst LAA emptying velocity ≤ 0.2 m/s within lateral wall. Moreover RAA AFCL > 165 ms was strongly related to the presence of LAA AFCL > 15 ms and > 165 ms. LAA and RAA functional assessment was predictive of the presence of advanced stages of voltage-defined LA fibrosis and its regional distribution among LSPAF population.

Electrophysiological function of the retina and optic nerve in patients with atrial fibrillation.

PURPOSE: To evaluate the effects of atrial fibrillation (AF) and ablation procedures on electrophysiological function in the retina and optic nerve. METHODS: Thirty two eyes of 17 patients with AF were analyzed. The full-field electroretinogram (ERG), pattern electroretinogram (PERG) and pattern visual evoked potential (PVEP) were performed. The results were compared to age-matched healthy controls (n = 30). In 12 eyes, electrophysiological tests were performed before and 3 months after ablation treatment. RESULTS: Statistically significant differences between AF patients and healthy controls were detected. In the full-field ERG, a reduction in the oscillatory potentials wave index (OPs WI; p = 0.012) and scotopic (0 dB) a-wave amplitude (p = 0.009) was observed. The amplitude of b-waves, scotopic (24 dB; p = 0.011), photopic single flash (p = 0.008) and photopic flicker (p = 0.009), was decreased. The photopic flicker b-wave peak time was increased (p = 0.005). Other parameters of ERG/PERG/PVEP did not differ significantly from controls. After the ablation procedure, the only statistically significant change was an increase in the OPs WI (p = 0.002). CONCLUSIONS: In the analyzed series of AF patients, retinal dysfunction was detected in the ERG test. The AF ablation may improve the retinal function as indicated by an increase in the OPs WI. The OPs WI has a potential value in the estimation of the effectiveness of AF ablation.

The Impact of Regional Maximum Tolerated Interlesion Distance on the Long-Term Ablation Outcomes in Ablation Index Guided Pulmonary Vein Isolation for Atrial Fibrillation.

BACKGROUND: An adequate interlesion distance (ILD) applied during point-by-point pulmonary vein (PV) isolation for atrial fibrillation (AF) has never been established. We hypothesized that maximum tolerated ILD may differ between PV regions and may influence long-term ablation outcomes. METHODS: A total of 260 AF patients underwent PV isolation with 3D electroanatomical platform. Postablation, ILD values were classified into 5 groups (6-5.5 mm, 5.5-5.0 mm, 5.0-4.5 mm, 4.5-4.0 mm and <4.0 mm); the number of tags in each group was calculated and correlated with postablation AF recurrence (AFR). All measurements were performed globally for the entire encirclement around each individual PV and regionally for designated PV anatomic segments. RESULTS: Single-procedure freedom from AF was 81% for paroxysmal and 66% for persistent AF at 12 months. Global analysis showed that AFR was not related to median ILD nor the number of lesions within each ILD tag group for any PV. Segmental analysis showed that AFR was not related to median ILD. However, the presence of tags from the 5.5-6.0 mm ILD group located on the posterior aspect of right upper PV (RUPV) correlated with AFR. This was confirmed in a multivariable logistic regression model. CONCLUSIONS: Maximum tolerated ILD of 6.0 mm translated into well-accepted ablation results. However, the study suggests that it may be inadequate at the posterior aspect of RUPV.

Successful catheter ablation of unmappable monomorphic postinfarction ventricular tachycardia guided by a Purkinje potential.

We describe a case of a patient with the history of a monomorphic postinfarction ventricular tachycardia that exhibited a right bundle branch block morphology and a superior axis. Because of electrical and hemodynamic instability of arrhythmia, classical mapping techniques were not applied. An electroanatomic voltage map during sinus rhythm was performed. A Purkinje potential (PP) preceding the QRS complex was recorded at posteroseptal area of a scar. Radiofrequency energy delivery at sites where a PP was detected resulted in a successful ablation.

Predictors of the voltage derived left atrial fibrosis in patients with long-standing persistent atrial fibrillation.

BACKGROUND: Left atrial (LA) arrhythmogenic substrate beyond the pulmonary veins (PV) seems to play a crucial role in the maintenance of atrial fibrillation (AF). The aim of this study was to evaluate the association of selected parameters with the presence and extent of voltage-defined LA fibrosis in patients with long-standing persistent AF (LSPAF) undergoing catheter ablation. METHODS: One hundred and sixteen consecutive patients underwent high density-high resolution voltage mapping of the LA with a multielectrode catheter following PV isolation and restoration of sinus rhythm with cardioversion. A non-invasive dataset, such as clinical variables, two-and three-dimensional echocardiography determined LA size and function and fibrillatory-wave amplitude on a standard surface electrocardiogram were obtained during AF before ablation. RESULTS: Low-voltage areas (LVA; 15 cm² [IQR 8-31]) were detected in 56% of patients. Twenty nine percent of them presented mild, 43% moderate and 28% severe global LVA burden. In univariate analysis, age ≥ 57 years old, female sex, body surface area ≤ 1.76 m², valvular heart disease, moderate mitral regurgitation, chronic coronary syndrome, hypothyroidism, CHA2DS2-VASc score ≥ 3 and ≥ 4 predicted the presence of LVA. In multivariate analysis only female sex, valvular heart disease and CHA2DS2-VASc ≥ 4 remained statistically significant. AF duration, LA size and function and fibrillatory-waves amplitude were neither associated with the prediction of the LVA, nor severe LVA burden. CONCLUSIONS: A LSPAF diagnosis does not indicate the presence of voltage defined fibrosis in many cases. Simple non-invasive screening of the LSPAF population could predict LVA prevalence.

Does a Vagal Response Indicate Cardiac Autonomic Modulation and Improve the Therapeutic Effect of Pulmonary Vein Isolation in Patients with Paroxysmal Atrial Fibrillation? Insights from Cryoballoon Ablation.

Background: The incidence and influence of vagal response (VR) observed during cryoballoon-based pulmonary vein isolation (CBA-based PVI) on the cardiac autonomic nervous system (CANS) and ablation outcomes in paroxysmal atrial fibrillation (PAF) remain unknown. Methods: 296 patients were treated with a 28 mm second-generation cryoballoon (Medtronic). A total of 74 patients without structural heart disease and concomitant diseases were chosen for a detailed CANS assessment with a heart rate variability (HRV) analysis. All patients were screened over a 2-year post-ablation period. Results: VR was detected in 30% of patients and included sinus arrest (64%) or severe sinus bradycardia (46%). The presence of VR was not related to PV ostial dimension, patient clinical characteristics or intraprocedural ablation details. CANS modulation, manifesting as increased median HR and decreased HRV parameters with intact sympatho-vagal balance occurred independently of VR presence or absence and sustained for at least 12 months following ablation. VR was not related with more intensive CANS modulation and did not translate into better ablation outcomes when compared to the non-VR group (74% vs. 71% at 12 months and 69% vs. 65% at 24 months respectively). Conclusions: VR is frequent during CBA-based PVI for PAF and unrelated to any additional clinical benefit.

Atrial fibrillation risk scores to evaluate left atrial substrate based on voltage analysis in long-standing persistent type of arrhythmia.

BACKGROUND: Pre-ablation identification of left atrial (LA) low voltage areas (LVA) among long-standing persistent atrial fibrillation (LSPAF) population remains challenging. AIMS: The aim of the study was to analyze the potential of selected scores originally developed to assess arrhythmia recurrences, thromboembolic complications, or progression from paroxysmal to persistent AF to predict the presence of LA-LVA in LSPAF patients. METHODS: One hundred and fifty-two patients underwent pulmonary vein isolation followed by high-density-high-resolution LA voltage mapping. AF risk scores, such as APPLE, ATLAS, CAAP-AF, DR-FLASH, CHA2DS2-VASc, and HATCH were retrospectively calculated. A receiver operating characteristic curve analysis was performed to evaluate the ability of the scores to predict LVA. RESULTS: Low voltage areas were detected in 52% of the patients. 28% of the patients with LVA presented severe global LVA burden, whereas 56% of the patients showed a disseminated pattern of remodeling. CAAP-AF ≥7, DR-FLASH ≥4, and CHA2DS2-VASc ≥3 predicted the presence of LVA, whereas ATLAS ≤7 indicated the absence of LVA. ATLAS ≤8, CAAP-AF ≤9, DR-FLASH ≤4, and CHA2DS2-VASc ≤3 predicted the absence of severe LVA. APPLE ≤3 and CHA2DS2-VASc ≤2 predicted the absence of a LVA disseminated pattern. Among predictive scores, ATLAS (AUC, 0.633, 95% CI, 0.543-0.723, P = 0.004), DR-FLASH (AUC, 0.696; 95% CI, 0.594-0.81; P <0.001), and CHA2DS2-VASc (AUC, 0.644; 95% CI 0.518-0.77; P = 0.025) were the best predictors for the absence of LVA, severe LVA and a disseminated pattern of LVA, respectively. CONCLUSIONS: Atrial fibrillation risk stratification with specific scoring systems can unmask the presence of LA-LVA in the LSPAF population.

[Unusual induction of the typical slow-fast AVNRT in a patient with multiple slow atrioventricular pathways]. / Nietypowy mechanizm indukcji typowego czestoskurczu wezlowego nawrotnego u chorego z cechami wielu wolnych dróg przewodzenia w laczu przedsionkowo-komorowym.

A case of a male patient with a history of supraventricular tachycardia confirmed by electrophysiological study and treated by RF ablation is presented. The features of multiple slow atrioventricular nodal pathways were found as well as the unusual induction mechanism of the slow-fast atrioventricular nodal reentry tachycardia - 1 : 2 AV conduction.

The effect of atrial pacing site on electrophysiological properties of the atrioventricular junction and induction of atrioventricular nodal reentry in patients with typical atrioventricular nodal reentrant tachycardia.

BACKGROUND: Clinical studies in humans have shown the site of atrial stimulation to influence atrioventricular (AV) conduction times and refractory periods, the demonstration of dual AV nodal (AVN) pathways, and induction of AVN reentry. These studies often found conflicting results. Moreover, among enrolled patients a minority of them were found to have AVN reentrant tachycardia (AVNRT). AIM: The purpose of this study was to investigate the effect of right and left atrial pacing on the electrophysiological properties of the AV junction in the typical AVNRT population. METHODS: Ninety-two consecutive patients with typical AVNRT were included. Atrial pacing was performed from the high right atrium (HRA) and the left atrium via the proximal coronary sinus (CS). RESULTS: Stimulation from either the HRA or the CS could result in dual AVN physiology and AVNRT. No site-dependent differences in the ease of induction of dual AVN pathways with variability of initiation from either site were found. However, AVNRT was easier to induce from the HRA. With CS pacing the leftward but not the rightward AVN approaches were the entry point to the AV node because of significantly shorter AH conduction times compared to HRA pacing. Conduction over the leftward AVN extensions could initiate the tachycardia with significantly shorter critical AH interval compared to conduction over the rightward AVN extensions; however, the AH interval during AVNRT and its cycle length were not significantly different. CONCLUSIONS: Rightward and leftward AVN extensions are regular features of the AV node. Their different electrophysiological properties lead to variation in the demonstration of discontinuous AVN conduction and AVNRT during right and left atrial pacing. Despite the observation that the left AVN extensions could compose the entry point to the reentrant circuit, there is no evidence that they constitute the critical component of sustained typical AVNRT.

Tako-tsubo cardiomyopathy following complete atrioventricular nodal heart block during transcatheter radiofrequency ablation of atrioventricular nodal reentrant tachycardia.

We report a case of tako-tsubo cardiomyopathy after an unintentional atrioventricular (AV) block during an ablation procedure in a 77 year-old woman. This intriguing case explores three possible reasons that could have triggered the disease: (1) slow pathway destruction; (2) AV nodal complete heart block; (3) the overall stress the patient had experienced.

Ventricular and supraventricular arrhythmias and heart failure in a patient with left ventricular noncompaction and Brugada syndrome.

We report a 47 year-old male patient with coexistence of left ventricular noncompaction and Brugada syndrome. He presented malignant ventricular arrhythmias followed by cardioverter- -defibrillator implantation, atrial fibrillation and flutter and progressive heart failure. This case could be an example of the coexistence of two rare diseases of various genetic patterns that only partially showed overlapping symptomatology and complications, particularly ventricular arrhythmias.

Microvolt T-wave alternans for the risk stratification of dangerous ventricular arrhythmias in patients with previously implanted automatic cardioverter-defibrillator.

BACKGROUND: Sudden cardiac death (SCD) is the main cause of death in patients with reduced left ventricular ejection fraction (LVEF). Implantation of an automatic cardioverter-defibrillator (ICD) significantly reduces mortality of these patients. T-wave alternans (TWA) analysis is a relatively new method of SCD risk stratification. However, it's prognostic role in patients with ICD has not yet been fully established. AIM: To assess the predictive value of TWA in patients with previously implanted ICD. METHODS: The study included 67 patients with properly functioning ICD (54 men and 13 women, aged 62.2 ± 8.4 years). All patients underwent TWA analysis on the treadmill using the Cambridge Heart 2000 system. Results were considered as positive, negative or indeterminate. Each patient had at least 1 clinical control visit with ICD interrogation during the 12 ± ± 6 months of follow-up. The recurrence of sustained ventricular arrhythmias: ventricular tachycardia (VT) or ventricular fibrillation (VF) was analysed. RESULTS: No significant relationship was found between previous infarction (p = 0.810), aetiology (p = 0.768), LVEF (p = 0.413) or age (p = 0.562) and the incidence of arrhythmia during follow-up. The results of TWA were not significantly different between patients with or without VT or VF. The TWA analysis identified patients with arrhythmia recurrences with a sensitivity of 62%, specificity of 49%, negative predictive value of 81%, and positive predictive value of 28%. The TWA performance was better in patients with non-ischaemic than ischaemic cardiomyopathy (negative predictive value: 100%, positive predictive value: 75%). CONCLUSIONS: The TWA alternans was moderately effective for identification of patients with ICD and ventricular arrhythmia recurrences. The test was most useful for identification of patients with non-ischaemic cardiomyopathy who are of low arrhythmic risk.