The Influence of Different Multipolar Mapping Catheter Types on Procedural Outcomes in Patients Undergoing Pulmonary Vein Isolation for Atrial Fibrillation.

(1) Background: During pulmonary vein isolation (PVI) for atrial fibrillation (AF), multipolar mapping catheters (MMC) are often used. We aimed to compare the procedural outcomes of two MMCs, specifically a circular-shaped and a five-spline-shaped MMC. (2) Methods: We enrolled 70 consecutive patients in our prospective, observational trial undergoing PVI procedures for paroxysmal AF. The initial 35 patients underwent PVI procedures with circular-shaped MMC guidance (Lasso Group), and the procedures for the latter 35 cases were performed using five-spline-shaped MMC (PentaRay Group). (3) Results: No significant differences were identified between the two groups in total procedure time (80.2 ± 17.7 min vs. 75.7 ± 14.8 min, p = 0.13), time from femoral vein puncture to the initiation of the mapping (31.2 ± 7 min vs. 28.9 ± 6.8, p = 0.80), mapping time (8 (6; 13) min vs. 9 (6.5; 10.5) min, p = 0.73), duration between the first and last ablation (32 (30; 36) min vs. 33 (26; 40) min, p = 0.52), validation time (3 (2; 4) min vs. 3 (1; 5) min, p = 0.46), first pass success rates (89% vs. 91%, p = 0.71), left atrial dwelling time (46 (37; 53) min vs. 45 (36.5; 53) min, p = 0.56), fluoroscopy data (time: 150 ± 71 s vs. 143 ± 56 s, p = 0.14; dose: 6.7 ± 4 mGy vs. 7.4 ± 4.4 mGy, p = 0.90), total ablation time (1187 (1063; 1534) s vs. 1150.5 (1053; 1393.5) s, p = 0.49), the number of ablations (78 (73; 93) vs. 83 (71.3; 92.8), p = 0.60), and total ablation energy (52,300 (47,265; 66,804) J vs. 49,666 (46,395; 56,502) J, p = 0.35). (4) Conclusions: This study finds comparable procedural outcomes bet-ween circular-shaped and five-spline-shaped MMCs for PVI in paroxysmal AF, supporting their interchangeability in clinical practice for anatomical mapping.

Feasibility and safety of cavotricuspid isthmus ablation using exclusive intracardiac echocardiography guidance: a proof-of-concept, observational trial.

Introduction: Catheter ablation is the preferred treatment for typical atrial flutter (AFl), but it can be challenging due to anatomical abnormalities. The use of 3D electroanatomical mapping systems (EAMS) has reduced fluoroscopy exposure during AFl ablation. Intracardiac echocardiography (ICE) has also shown benefits in reducing radiation exposure during AFl ablation. However, there is a lack of evidence on the feasibility of ICE-guided, zero-fluoroscopy AFl ablation without the use of EAMS. Methods: In this prospective study, we enrolled 80 patients with CTI-dependent AFl. The first 40 patients underwent standard fluoroscopy + ICE-guided ablation (Standard ICE group), while the other 40 patients underwent zero-fluoroscopy ablation using only ICE (Zero ICE group). Procedure outcomes, including acute success, procedure time, fluoroscopy time, radiation dose, and complications, were compared between the groups. Results: The acute success rate was 100% in both groups. Out of the 40 cases, the zero-fluoroscopy strategy was successfully implemented in 39 cases (97.5%) in the Zero ICE group. There were no significant differences in procedure time [55.5 (46.5; 66.8) min vs. 51.5 (44.0; 65.5), p = 0.50] and puncture to first ablation time [18 (13.5; 23) min vs. 19 (15; 23.5) min, p = 0.50] between the groups. The Zero ICE group had significantly lower fluoroscopy time [57 (36.3; 90) sec vs. 0 (0; 0) sec, p < 0.001] and dose [3.17 (2.27; 5.63) mGy vs. 0 (0; 0) mGy, p < 0.001] compared to the Standard ICE group. Total ablation time was longer in the Standard ICE group [597 (447; 908) sec vs. 430 (260; 750), p = 0.02], but total ablation energy [22,458 (14,836; 31,116) Ws vs. 17,043 (10,533; 29,302) Ws, p = 0.10] did not differ significantly. First-pass bidirectional conduction block of the CTI and acute reconnection rates were similar between the groups. No complications or recurrences were observed during the follow-up period. Conclusion: Our study suggests that zero-fluoroscopy CTI ablation guided solely by ICE for AFl is feasible and safe. Further investigation is warranted for broader validation.

Intracardiac Echocardiography Guidance Improves Procedural Outcomes in Patients Undergoing Cavotricuspidal Isthmus Ablation for Typical Atrial Flutter.

Atrial flutter (AFL) represents a prevalent variant of supraventricular tachycardia, distinguished by a macro-reentrant pathway encompassing the cavotricuspid isthmus (CTI). Radiofrequency (RF) catheter ablation stands as the favored therapeutic modality for managing recurring CTI-dependent AFL. Intracardiac echocardiography (ICE) has been proposed as a method to reduce radiation exposure during CTI ablation. This study aims to comprehensively compare procedural parameters between ICE-guided CTI ablation and fluoroscopy-only procedures. A total of 370 consecutive patients were enrolled in our single-center retrospective study. In 151 patients, procedures were performed using fluoroscopy guidance only, while 219 patients underwent ICE-guided CTI ablation. ICE guidance significantly reduced fluoroscopy time (73 (36; 175) s vs. 900 (566; 1179) s; p < 0.001), fluoroscopy dose (2.45 (0.6; 5.1) mGy vs. 40.5 (25.7; 62.9) mGy; p < 0.001), and total procedure time (70 (52; 90) min vs. 87.5 (60; 102.5) min; p < 0.001). Total ablation time (657 (412; 981) s vs. 910 (616; 1367) s; p < 0.001) and the time from the first to last ablation (20 (11; 36) min vs. 40 (25; 55) min; p < 0.01) were also significantly shorter in the ICE-guided group. Acute success rate was 100% in both groups, and no major complications occurred in either group. ICE-guided CTI ablation in patients with AFL resulted in shorter procedure times, reduced fluoroscopy exposure, and decreased ablation times, compared to the standard fluoroscopy-only approach.

Electroanatomical Mapping System-Guided vs. Intracardiac Echocardiography-Guided Slow Pathway Ablation: A Randomized, Single-Center Trial.

Radiofrequency (RF) catheter ablation is an effective treatment option for targeting the slow pathway (SP) in atrioventricular nodal reentry tachycardia (AVNRT). Previous data suggested that using intracardiac echocardiography (ICE) guidance could improve procedural outcomes when compared to using fluoroscopy alone. In this prospective study, we aimed to compare the effectiveness of an electroanatomical mapping system (EAMS)-guided approach with an ICE-guided approach for SP ablation. Eighty patients undergoing SP ablation for AVNRT were randomly assigned to either the ICE-guided or EAMS-guided group. If the procedural endpoint was not achieved after 8 RF applications; patients were allowed to crossover to the ICE-guided group. The ICE-guided approach reduced the total procedure time (61.0 (56.0; 66.8) min vs. 71.5 (61.0; 80.8) min, p < 0.01). However, the total fluoroscopy time was shorter (0 (0-0) s vs. 83.5 (58.5-133.25) s, p < 0.001) and the radiation dose was lower (0 (0-0) mGy vs. 3.3 (2.0-4.7) mGy, p < 0.001) with EAMS-guidance. The ICE-guided group had a lower number of RF applications (4 (3-5) vs. 5 (3.0-7.8), p = 0.03) and total ablation time (98.5 (66.8-186) s vs. 136.5 (100.5-215.8) s, p = 0.02). Nine out of 40 patients (22.5%) in the EAMS-guided group crossed over to the ICE-guided group, and they were successfully treated with similar RF applications in terms of number, time, and energy compared to the ICE-guided group. There were no recurrences during the follow-up period. In conclusion, the utilization of ICE guidance during SP ablation has demonstrated notable reductions in procedural time and RF delivery when compared to procedures guided by EAMS. In challenging cases, an early switch to ICE-guided ablation may be the optimal choice for achieving successful treatment.

Zero fluoroscopy catheter ablation for atrial fibrillation: a systematic review and meta-analysis.

Introduction: Catheter ablation for atrial fibrillation (AF) is the most frequently performed cardiac ablation procedure worldwide. The majority of ablations can now be performed safely with minimal radiation exposure or even without the use of fluoroscopy, thanks to advances in 3-dimensional electroanatomical mapping systems and/or intracardiac echocardiography. The aim of this study was to conduct a meta-analysis to compare the effectiveness of zero fluoroscopy (ZF) versus non-zero fluoroscopy (NZF) strategies for AF ablation procedures. Methods: Electronic databases were searched and systematically reviewed for studies comparing procedural parameters and outcomes of ZF vs. NZF approaches in patients undergoing catheter ablation for AF. We used a random-effects model to derive the mean difference (MD) and risk ratios (RR) with a 95% confidence interval (CI). Results: Our meta-analysis included seven studies comprising 1,593 patients. The ZF approach was found to be feasible in 95.1% of patients. Compared to the NZF approach, the ZF approach significantly reduced procedure time [mean difference (MD): -9.11 min (95% CI: -12.93 to -5.30 min; p < 0.01)], fluoroscopy time [MD: -5.21 min (95% CI: -5.51 to -4.91 min; p < 0.01)], and fluoroscopy dose [MD: -3.96 mGy (95% CI: -4.27 to -3.64; p < 0.01)]. However, there was no significant difference between the two groups in terms of total ablation time [MD: -104.26 s (95% CI: -183.37 to -25.14; p = 0.12)]. Furthermore, there was no significant difference in the acute [risk ratio (RR): 1.01, 95% CI: 1.00-1.02; p = 0.72] and long-term success rates (RR: 0.96, 95% CI: 0.90-1.03; p = 0.56) between the ZF and NZF methods. The complication rate was 2.76% in the entire study population and did not differ between the groups (RR: 0.94, 95% CI: 0.41-2.15; p = 0.89). Conclusion: The ZF approach is a feasible method for AF ablation procedures. It significantly reduces procedure time and radiation exposure without compromising the acute and long-term success rates or complication rates.

Case series of catheter-based arrhythmia ablation in 13 pregnant women.

BACKGROUND: Catheter ablation is a rarely used procedure to treat arrhythmias during pregnancy. HYPOTHESIS: In the case of maternal arrhythmia during pregnancy, zero-fluoroscopic catheter ablation is preferable to medical treatment. METHODS: Between April 2014 and September 2021, we examined the demographic data, procedural parameters, and fetal and maternal outcomes in pregnant women undergoing ablation at the Gottsegen National Cardiovascular Center and University of Pécs Medical School, Heart Institute. RESULTS: Fourteen procedures (14 electrophysiological studies [EPS], 13 ablations) performed on 13 pregnant women (age 30.3 ± 5.2 years, primipara n = 6) were studied. During EPS, 12 patients had inducible arrhythmias. Atrial tachycardia was confirmed in three, atrioventricular re-entry tachycardia via manifest accessory pathway (AP) in three, and via concealed AP in one case. Atrioventricular nodal re-entry tachycardia was confirmed in three and sustained monomorphic ventricular tachycardia in two cases. Eleven radiofrequency ablation (84.6%) and two cryoablation (15.4%) were performed. The electroanatomical mapping system was used in all cases. Transseptal puncture was performed in two cases (15.4%) due to left lateral APs. The mean procedure time was 76.0±33.0 minutes. All procedures were performed without fluoroscopy. No complications occurred. During the follow-up, arrhythmia-free survival was achieved in all cases, but in two patients, we used antiarrhythmic drugs (AADs) to achieve it. APGAR score was within the normal range in all cases [median (interquartile range), 9.0/10.0 (9.0-10.0/9.3-10.0)]. CONCLUSIONS: Zero-fluoroscopic catheter ablation was an effective and safe treatment option for our 13 pregnant patients. Catheter ablation may have less side effects on fetal development than the use of AADs during pregnancy.

Visualizable vs. standard, non-visualizable steerable sheath for pulmonary vein isolation procedures: Randomized, single-centre trial.

Introduction: Steerable sheaths (SSs) are frequently used to improve catheter contact during pulmonary vein isolation (PVI) procedures. A new type of visualizable (by electroanatomical mapping system) SS has become available in clinical treatment. Purpose: We aimed to compare procedural data of visualizable vs. non-visualizable steerable sheath assisted PVI procedures in patients with atrial fibrillation (AF). Methods: In this single-centre randomized study, we enrolled a total of 100 consecutive patients who underwent PVI due to AF. Results: A total of 100 patients were randomized into 2 groups (visualizable SS group: 50; non-visualizable SS group: 50). Acute ablation success was 100% and the rate of the first pass isolation were similar (92% vs. 89%; p = 0.88). Using visualizable SS, left atrial (LA) procedure time (53.1 [41.3; 73.1] min vs. 59.5 [47.6; 74.1] min.; p = 0.04), LA fluoroscopy time (0 [0; 0] s vs. 17.5 [5.5; 69.25] s; p < 0.01) and LA fluoroscopy dose (0 [0; 0.27] mGy vs. 0.74 [0.16; 2.34] mGy; p < 0.01) was significantly less, however, there was no difference in the total procedural time (90 ± 35.2 min vs. 99.5 ± 31.8 min; p = 0.13), total fluoroscopy time (184 ± 89 s vs. 193 ± 44 s; p = 0.79), and total fluoroscopy dose (9.12 ± 1.98 mGy vs. 9.97 ± 2.27 mGy; p = 0.76). Compared to standard, non-visualizable SS group, the number of radiofrequency ablations was fewer (69 [58; 80] vs. 79 [73; 86); p < 0.01) as well as total ablation time was reduced (1049 sec. [853; 1175] vs. 1265 sec. [1085; 1441]; p < 0.01) in the visualizable SS cohort. No major complications occurred in either group. Conclusion: Compared to the standard, non-visualizable SS, visualizable SS significantly reduces the left atrial procedure time, RF delivery and fluoroscopy exposure without compromising its safety or effectiveness in patients undergoing PVI procedures for AF.

3D MRI left atrial scar map guided anatomical pulmonary vein reisolation / 3D MRI bal pitvari hegtérkép által vezérelt anatómiai pulmonalis véna reizoláció

We present the case of a 58-year-old woman, suffering from high blood pressure, who presented with documented frequently occurring paroxysmal atrial fibrillation attacks. She underwent two prior pulmonary vein isolations, but her palpitations did not cease. We aimed to achieve a long period free of symptoms, and a 3D MRI late enhancement scar map of the left atrium was obtained before the planned third pulmonary vein isolation procedure to visualize the assumed pulmonary vein reconnection sites. First, the endocardial and epicardial contours of the thin left atrial wall were manually determined on the images, then color-coding was added based on the trasmurality of contrast enhancement in the wall. The reconstructed 3D color-coded left atrial surface revealed the localization of left atrial antral wall scars. These images were integrated into the electroanatomical mapping system and ablation was carried out selectively on the spots showing gaps in the antral scar. Isolation was achieved in all four veins without any complications. The patient has become symptom-free for years now. The reconstructed left atrial 3D MRI images gained in an innovative process visualized the gaps in the previous ablation lines and these images were integrated to guide the first gap-closure redo pulmonary vein isolation procedure in Hungary.

Zero and Minimal Fluoroscopic Approaches During Ablation of Supraventricular Tachycardias: A Systematic Review and Meta-Analysis.

Introduction: Catheter ablations for cardiac arrhythmias are conventionally performed under fluoroscopic guidance. To guide these procedures, zero/minimal fluoroscopy (Z/MF) approaches have become available, using three-dimensional electroanatomical mapping systems. Our aim was to conduct a meta-analysis comparing these two different methods for the treatment of paroxysmal supraventricular tachycardia (SVT). Methods: Electronic databases were searched and systematically reviewed for studies comparing procedural parameters and outcomes of conventional, fluoroscopy-guided vs. Z/MF approaches in patients undergoing electrophysiology (EP) procedures for SVTs. The random-effects model was used to derive mean difference (MD) and risk ratios (RRs) with 95% confidence interval (CI). Results: Twenty-four studies involving 9,074 patients met our inclusion criteria. There was no difference between the groups in terms of acute success rate (RR = 1.00, 95% CI, 0.99-1.01; p = 0.97) and long-term success rate (RR: 1.01, 95% CI, 1.00-1.03; p = 0.13). Compared to the conventional method, zero-and-minimal fluoroscopy (Z/MF) ablation significantly reduced fluoroscopic time [MD: -1.58 min (95% CI, -2.21 to -0.96 min; p < 0.01)] and ablation time [MD: -25.23 s (95% CI: -42.04 to -8.43 s; p < 0.01)]. No difference could be detected between the two groups in terms of the procedure time [MD: 3.06 min (95% CI: -0.97 to 7.08; p = 0.14)] and the number of ablation applications [MD: 0.13 (95% CI: -0.86 to 1.11; p = 0.80)]. The complication rate was 1.59% in the entire study population and did not differ among the groups (RR: 0.68, 95% CI: 0.45-1.05; p = 0.08). Conclusions: The Z/MF approach for the catheter ablation of SVTs is a feasible method that reduces radiation exposure and ablation time without compromising the acute and long-term success or complication rates.

Evaluation of pulse wave velocity for predicting major adverse cardiovascular events in post-infarcted patients; comparison of oscillometric and MRI methods.

Increased aortic pulse wave velocity (PWV) has been proved as a strong predictor of major adverse cardiovascular events (MACE) in patients after myocardial infarction (MI). Due to the various technical approaches the level of high PWV values show significant differences. We evaluated the cut-off PWV values for MACE prediction using cardiac magnetic resonance imaging (CMR) and oscillometric methods for validating the prognostic value of high PWV in post-infarcted patients. Phase contrast imaging (PCI) and oscillometric based Arteriograph (AG) were compared in this 6 years follow-up study, including 75 consecutive patients of whom 49 suffered previous ST-elevation myocardial infarction (STEMI). Patients received follow-up for MACE comprising all-cause death, non-fatal MI, ischemic stroke, hospitalization for heart failure and coronary revascularization. An acceptable agreement and significant correlation (rho: 0.332, p < 0.01) was found between AG and CMR derived PWV values. The absolute values, however, were significantly higher for AG (median (IQR): 10.4 (9.2-11.9) vs 6.44 (5.64-7.5) m/s; p < 0.001). Totally 51 MACE events occurred during the 6 years follow-up period in post-infarcted patients. Kaplan-Meier analysis in both methods showed significantly lower event-free survival in case of high PWV (CMR: >6.47 m/s, AG: >9.625 m/s, p < 0.001, respectively). Multivariate Cox regression revealed PWV as a predictor of MACE (PWV CMR hazard ratio (HR): 1.31 (CI: 1.1-1.7), PWV AG HR: 1.24 (CI: 1.0-1.5), p < 0.05, respectively). Increased PWV derived by AG and CMR methods are feasible for MACE prediction in post-infarcted patients. However, adjusted cut-off values of PWV are recommended for different techniques to improve individual risk stratification.

Successful termination of ventricular arrhythmias with implantable cardioverter defibrillator in a patient with myotonic dystrophy / Implantálható kardioverter-defibrillátor által sikeresen megszüntetett malignus kamrai ritmuszavar dystrophia myotonicában szenvedo betegben.

Összefoglaló. A dystrophia myotonica (DM) multiszisztémás, autoszomális domináns módon öröklodo, többségében felnottkori izombetegség, melynek incidenciája 1 : 8000. A betegség kapcsán fellépo izomszöveti degeneráció a harántcsíkolt izomszövet átépülése mellett a szívizomszövetet is érinti, ami fontos oki szerepet játszik az érintett betegek csökkent várható élettartamában. A DM-ben szenvedok halálozásának közel egyharmadáért a cardiovascularis okok tehetok felelossé. Esetriportunkban egy 52 éves, korábban kritikus bradycardia és I. fokú atrioventricularis blokk miatt pacemakerimplantáción átesett, DM-mel diagnosztizált nobeteg kardiológiai utánkövetését mutatjuk be. A hirtelen szívhalál rizikóstratifikációja céljából elvégzett invazív elektrofiziológiai vizsgálat során kamrafibrilláció lépett fel, így a korábban implantált pacemakerelektródák mellé sokkelektróda került beültetésre, a pacemakerkészüléket implantálható kardioverter-defibrillátorra (ICD) cseréltük. Az 1 éves ICD-kontrollvizsgálat során azt találtuk, hogy a beültetés óta 22, tartós kamrai tachycardiával járó epizód lépett fel, melyek közül a készülék valamennyit sikeresen terminálta. Az eset bemutatásával szeretnénk rámutatni arra, hogy a magas cardiovascularis rizikócsoportba tartozó DM-betegek azonosítása kiemelkedo fontosságú lehet a hirtelen szívhalál megelozése érdekében. Orv Hetil. 2021; 162(46): 1856-1858. Summary. Myotonic dystrophy (DM) is one of the most frequent adulthood diseases of the skeletal muscles, which develops multisystemic features and shows autosomal dominant trait. In DM, tissue degeneration affects not only the skeletal, but the cardiac muscle, too. In one third of the patients, the cause of death is of cardiac origin. We report on our patient's case, who was diagnosed with DM at the age of 52, in whom episodes of critical bradycardia with first-degree atrioventricular block was detected, resulting in a pacemaker implantation. Invasive cardiac electrophysiological study was performed, during which ventricular fibrillation was registered. A shock electrode was added to the previously implanted pacemaker, enabling defibrillation in case of detection of a sustained ventricular arrhythmia. During the 1-year follow-up, 22 episodes of sustained ventricular tachycardia were identified, with the device successfully terminating the malignant arrhythmias. Our case shows that electrophysiological study and the succeeding implantation of an implantable cardiac defibrillator is highly important in identifying and terminating ventricular arrhythmias in high-risk DM patients. Orv Hetil. 2021; 162(46): 1856-1858.

Left and right ventricular parameters corrected with threshold-based quantification method in a normal cohort analyzed by three independent observers with various training-degree.

While cardiac magnetic resonance (CMR) is the reference method to evaluate left and right ventricular functions, volumes and masses, there is no widely accepted method for the quantitative analysis of trabeculae and papillary muscles (TPM). The aim of this study was to investigate the effect of TPM quantification on left and right ventricular CMR values in a normal cohort and to investigate interobserver variability of threshold-based (TB) analysis by three independent observers with variant experience in CMR. At our clinic, 60 healthy volunteers (30 males, mean age 25.6 ± 4.7 years) underwent CMR scan performed on a 1.5T Philips Achieva MR machine. On short-axis cine images, endo- and epicardial contours were detected by three independent observers with variable experience in CMR (low- ca. 120, mid- > 800, high-experienced > 5000 original CMR cases). Using Conv and TB methods (Medis 7.6 QMass software Leiden, The Netherland), we measured LV and RV ejection fractions, end-diastolic, end-systolic, stroke volumes and masses. We used TB method for quantifying TPM in ventricles using epicardial contour layers. Interobserver variability was evaluated, and the observer's experience as an impact on variability of each investigated parameters was assessed. Comparing Conv and TB quantification methods' significant difference were detected for all LV and RV parameters in case of all observers (H, M and L p < 0.0001). The global intraclass correlation coefficient (G-ICC) representing interobserver agreement for all investigated parameters was lower with Conv method (G-ICCConv vs. G-ICCTB 0.86 vs. 0.92 p < 0.0001). The ICC of LV parameters was higher using TB quantification (LV-ICCConv vs. LV-ICCTB 0.92 vs. 0.96 p < 0.0001), and for the evaluation of RV values, the TB method also had significantly higher interobserver agreement (RV-ICCConv vs. RV-ICCTB 0.80 vs. 0.89 p < 0.0001). The TB algorithm could be a consistent method to assess LV and RV CMR values, and to measure trabeculae and papillary muscles quantitatively in various level of experience in CMR.

The MRI characteristics of the no-flow region are similar in reperfused and non-reperfused myocardial infarcts: an MRI and histopathology study in swine.

BACKGROUND: The no-flow region (NF) visualised by magnetic resonance imaging (MRI) in myocardial infarction (MI) has been explained as the product of reperfusion-injury-induced microvascular obstruction. However, a similar MRI phenomenon occurs in non-reperfused MI. Accordingly, our purpose was to compare the MRI and histopathologic characteristics of the NF in reperfused and non-reperfused MIs. METHODS: Reperfused (n = 7) and non-reperfused MIs (n = 7) were generated in swine by percutaneous balloon occlusion and microsphere embolisation techniques. Four days post-MI, animals underwent myocardial T2-mapping, early and serial late gadolinium enhancement MRI. MI and NF were compared between the models using the independent samples t test. Serial measurements were analysed using repeated measures analysis of variance. Triphenyltetrazolium chloride (TTC) macroscopic and microscopic histopathologic assessment was also performed. RESULTS: The MI size in the reperfused and non-reperfused groups was 17.1 ± 3.4 ml and 19.4 ± 8.1 ml, respectively (p = 0.090), in agreement with TTC assessment (p = 0.216; p = 0.484), and the NF size was 7.7 ± 2.4 ml and 8.1 ± 1.9 ml, respectively (P = 0.211). Compared to the reference 2-min post-contrast measurement, the NF size was significantly reduced at 20 min in the reperfused group and at 25 min in the non-reperfused group (both p < 0.001). Nevertheless, the NF was still detectable at 45 min after injection. No significant T2 difference was observed between the groups (p > 0.326). Histopathologic assessment revealed extensive calcification and hemosiderin deposition in the NF of the reperfused MI, but not in the non-reperfused MI. CONCLUSIONS: The NF in non-reperfused and reperfused MIs have similar characteristics on MRI despite the different pathophysiologic and underlying histopathologic conditions, indicating that the presence of the NF alone cannot differentiate between these two types of MI.

Ictal asystole: A systematic review.

OBJECTIVE: To comprehensively analyze ictal asystole (IA) on a large number of subjects. METHODS: We performed a systematic review of case report studies of patients diagnosed with IA (1983-2016). Each included case was characterized with respect to patient history, IA seizure characteristics, diagnostic workup, and therapy. In addition, comparative analyses were also carried out: two alignments were developed based on the delay between epilepsy onset and IA onset ("new-onset" if <1 year, "late-onset" if ≥1 year) and asystole duration (asystole was "very prolonged" if lasted >30 s). RESULTS: One hundred fifty-seven cases were included. All patients had focal epilepsy. In 7% of cases IA developed during a secondary generalized tonic-clonic seizure. Both the seizure-onset zone and the focal seizure activity at asystole beginning were usually temporal (p < 0.001 and p = 0.001, respectively) and were lateralized to the left hemisphere in 62% (p = 0.005 and p = 0.05, respectively). Asystole duration was 18 ± 14 s (mean±SD) (range 3-96 s); 73% of patients had late-onset, 27% had new-onset IA. Compared to late-onset IA, new-onset IA was associated with female gender (p = 0.023), preexisting heart condition (p = 0.014), focal seizure activity at asystole beginning (p = 0.012), normal neuroimaging (p = 0.013), normal interictal EEG (p < 0.001), auditory aura (p = 0.012), and drug-responsive epilepsy (p < 0.001). "Very prolonged" asystole was associated with secondary generalized tonic-clonic seizures (p = 0.003) and tended to occur in extratemporal lobe seizures (p = 0.074). No IA-related death was reported. SIGNIFICANCE: Characteristics considered to be typical of IA (focal, left temporal seizures appearing on grounds of a long-lasting, intractable epilepsy) seem only partially legitimate. We suggest that in new-onset IA, female gender and a preexisting heart condition could serve as predispositions in an otherwise benign epilepsy. We speculate that in late-onset IA, male-predominant changes in neuronal networks in chronic, intractable epilepsy and an accompanying autonomic dysregulation serve as facilitating factors.

New Validated Signal-averaging-based Electrocardiography Method to Determine His-ventricle Interval.

BACKGROUND/AIM: The signal-averaging (SA) technique is used to record high-resolution electrocardiograms (HRECGs) showing cardiac micropotentials. We aimed to develop a non-invasive signal-averaging-based portable bedside device to determine His-ventricle interval. PATIENTS AND METHODS: After amplifying the HRECG recordings, signal duration and voltage can be measured up to four decimal precision. To validate our system, comparison of the invasively and non-invasively determined HV intervals has been performed in 20 patients. RESULTS: Our workgroup has developed a system capable of displaying and measuring cardiac micropotentials on storable ECG. Neither related paired-sample T-test (p=0.263) nor Wilcoxon's non-parametric signed ranks test (p=0.245) showed significant deviations of the HV intervals. Furthermore, related paired-sample T-test showed strong correlation (corr=0.910, p<0.001) between HV intervals determined by electrophysiology (EP) and non-invasive measurements. CONCLUSION: Our research group managed to assemble and validate an easy to use device capable of determining HV intervals even under ambulatory conditions.

Mutations in NEBL encoding the cardiac Z-disk protein nebulette are associated with various cardiomyopathies.

INTRODUCTION: Transgenic mice overexpressing mutated NEBL, encoding the cardiac-specific Z-disk protein nebulette, develop severe cardiac phenotypes. Since cardiomyopathies are commonly familial and because mutations in a single gene may result in variable phenotypes, we tested the hypothesis that NEBL mutations are associated with cardiomyopathy. MATERIAL AND METHODS: We analyzed 389 patients, including cohorts of patients with dilated cardiomyopathy (DCM), hypertrophic cardiomyopathy (HCM), and left ventricular non-compaction cardiomyopathy (LVNC). The 28 coding exons of the NEBL gene were sequenced. Further bioinformatic analysis was used to distinguish variants. RESULTS: In total, we identified six very rare heterozygous missense mutations in NEBL in 7 different patients (frequency 1.8%) in highly conserved codons. The mutations were not detectable in 320 Caucasian sex-matched unrelated individuals without cardiomyopathy and 192 Caucasian sex-matched blood donors without heart disease. Known cardiomyopathy genes were excluded in these patients. The mutations p.H171R and p.I652L were found in 2 HCM patients. Further, p.Q581R and p.S747L were detected in 2 DCM patients, while the mutation p.A175T was identified independently in two unrelated patients with DCM. One LVNC patient carried the mutation p.P916L. All HCM and DCM related mutations were located in the nebulin-like repeats, domains responsible for actin binding. Interestingly, the mutation associated with LVNC was located in the C-terminal serine-rich linker region. CONCLUSIONS: Our data suggest that NEBL mutations may cause various cardiomyopathies. We herein describe the first NEBL mutations in HCM and LVNC. Our findings underline the notion that the cardiomyopathies are true allelic diseases.

In Vitro Longitudinal Relaxivity Profile of Gd(ABE-DTTA), an Investigational Magnetic Resonance Imaging Contrast Agent.

PURPOSE: MRI contrast agents (CA) whose contrast enhancement remains relatively high even at the higher end of the magnetic field strength range would be desirable. The purpose of this work was to demonstrate such a desired magnetic field dependency of the longitudinal relaxivity for an experimental MRI CA, Gd(ABE-DTTA). MATERIALS AND METHODS: The relaxivity of 0.5mM and 1mM Gd(ABE-DTTA) was measured by Nuclear Magnetic Relaxation Dispersion (NMRD) in the range of 0.0002 to 1T. Two MRI and five NMR instruments were used to cover the range between 1.5 to 20T. Parallel measurement of a Gd-DTPA sample was performed throughout as reference. All measurements were carried out at 37°C and pH 7.4. RESULTS: The relaxivity values of 0.5mM and 1mM Gd(ABE-DTTA) measured at 1.5, 3, and 7T, within the presently clinically relevant magnetic field range, were 15.3, 11.8, 12.4 s-1mM-1 and 18.1, 16.7, and 13.5 s-1mM-1, respectively. The control 4 mM Gd-DTPA relaxivities at the same magnetic fields were 3.6, 3.3, and 3.0 s-1mM-1, respectively. CONCLUSIONS: The longitudinal relaxivity of Gd(ABE-DTTA) measured within the presently clinically relevant field range is three to five times higher than that of most commercially available agents. Thus, Gd(ABE-DTTA) could be a practical choice at any field strength currently used in clinical imaging including those at the higher end.

Age-independent myocardial infarct quantification by signal intensity percent infarct mapping in swine.

PURPOSE: To test whether signal intensity percent infarct mapping (SI-PIM) accurately determines the size of myocardial infarct (MI) regardless of infarct age. MATERIALS AND METHODS: Forty-five swine with reperfused MI underwent 1.5T late gadolinium enhancement (LGE) magnetic resonance imaging (MRI) after bolus injection of 0.2 mmol/kg Gd(DTPA) on days 2-62 following MI. Animals were classified into acute, healing, and healed groups by pathology. Infarct volume (IV) and infarct fraction (IF) were determined by two readers, using binary techniques (including 2-5 standard deviations [SD] above the remote, and full-width at half-maximum) and the SI-PIM method. Triphenyl-tetrazolium-chloride staining (TTC) was performed as reference. Bias (percent under/overestimation of IV relative to TTC) of each quantification method was calculated. Bland-Altman analysis was done to test the accuracy of the quantification methods, while intraclass correlation coefficient (ICC) analysis was done to assess intra- and interobserver agreement. RESULTS: Bias of the MRI quantification methods do not depend on the age of the MI. Full-width at half-maximum (FWHM) and SI-PIM gave the best estimate of MI volume determined by the reference TTC (P-values for the FWHM and SI-PIM methods were 0.183, 0.26, 0.95, and 0.073, 0.091, 0.73 in Group 1, Group 2, and Group 3, respectively), while using any of the binary thresholds of 2-4 SDs above the remote myocardium showed significant overestimation. The 5 SD method, however, provided similar IV compared to TTC and was shown to be independent of the size and age of MI. ICC analysis showed excellent inter- and intraobserver agreement between the readers. CONCLUSION: Our results indicate that the SI-PIM method can accurately determine MI volume regardless of the pathological stage of MI. Once tested, it may prove to be useful for the clinic.

Infarct density distribution by MRI in the porcine model of acute and chronic myocardial infarction as a potential method transferable to the clinic.

To study the feasibility of a myocardial infarct (MI) quantification method [signal intensity-based percent infarct mapping (SI-PIM)] that is able to evaluate not only the size, but also the density distribution of the MI. In 14 male swine, MI was generated by 90 min of closed-chest balloon occlusion followed by reperfusion. Seven (n = 7) or 56 (n = 7) days after reperfusion, Gd-DTPA-bolus and continuous-infusion enhanced late gadolinium enhancement (LGE) MRI, and R1-mapping were carried out and post mortem triphenyl-tetrazolium-chloride (TTC) staining was performed. MI was quantified using binary [2 or 5 standard deviation (SD)], SI-PIM and R1-PIM methods. Infarct fraction (IF), and infarct-involved voxel fraction (IIVF) were determined by each MRI method. Bias of each method was compared to the TTC technique. The accuracy of MI quantification did not depend on the method of contrast administration or the age of the MI. IFs obtained by either of the two PIM methods were statistically not different from the IFs derived from the TTC measurements at either MI age. IFs obtained from the binary 2SD method overestimated IF obtained from TTC. IIVF among the three different PIM methods did not vary, but with the binary methods the IIVF gradually decreased with increasing the threshold limit. The advantage of SI-PIM over the conventional binary method is the ability to represent not only IF but also the density distribution of the MI. Since the SI-PIM methods are based on a single LGE acquisition, the bolus-data-based SI-PIM method can effortlessly be incorporated into the clinical image post-processing procedure.

Evaluation of experimental myocardial infarction models via electromechanical mapping and magnetic resonance imaging.

The diagnostic characteristics of electromechanical mapping (EMM) were evaluated in porcine myocardial infarction (MI) models with the parallel application of cardiac magnetic resonance imaging (cMRI) from the aspect of different pathophysiology and localization. Balloon occlusion in the left anterior descending coronary artery (LAD balloon group) or coil deployment in the LAD (LAD coil group) or circumflex artery (Cx coil group) was applied percutaneously in 16 domestic pigs. Regional left ventricular viability data were captured via cMRI and EMM. The unipolar voltage (UV) value was significantly decreased in segments containing transmural and subendocardial late enhancement compared with viable segments in the LAD balloon, LAD coil, and Cx coil groups. Receiver operating characteristic analysis revealed area under the curve values of 0.809 and 0.691 in the LAD infarct territory, and 0.864 and 0.855 in the Cx infarct territory for the UV compared with cMRI viability results as transmural late enhancement or viable tissue and subendocardial late enhancement or viable tissue, respectively. In conclusion, the UV value detected the presence of scar tissue with differential transmural extent and which represented proper diagnostic features both in the reperfused and nonreperfused models. This data could provide additional benefit in the clinical use of EMM for diagnostic purposes.