Modern mapping and ablation of idiopathic outflow tract ventricular arrhythmias

Outflow tract (OT) premature ventricular complexes (PVCs) are being recognized as a common and often troubling, clinical electrocardiographic finding. The OT areas consist of the Right Ventricular Outflow Tract (RVOT), the Left Ventricular Outflow Tract (LVOT), the Aortomitral Continuity (AMC), the aortic cusps and the Left Ventricular (LV) summit. By definition, all OT PVCs will exhibit an inferior QRS axis, defined as positive net forces in leads II, III and aVF. Activation mapping using the contemporary 3D mapping systems followed by pace mapping is the cornerstone strategy of every ablation procedure in these patients. In this mini review we discuss in brief all the modern mapping and ablation modalities for successful elimination of OT PVCs, along with the potential advantages and disadvantages of each ablation technique

The role of cardiac magnetic resonance in identifying appropriate candidates for cardiac resynchronization therapy - a systematic review of the literature

Despite the strict indications for cardiac resynchronization therapy (CRT) implantation, a significant proportion of patients will fail to adequately respond to the treatment. This systematic review aims to present the existing evidence about the role of cardiac magnetic resonance (CMR) in identifying patients who are likely to respond better to the CRT. A systematic search in the MedLine database and Cochrane Library from their inception to August 2021 was performed, without any limitations, by two independent investigators. We considered eligible observational studies or randomized clinical trials (RCTs) that enrolled patients > 18 years old with heart failure (HF) of ischaemic or non-ischaemic aetiology and provided data about the association of baseline CMR variables with clinical or echocardiographic response to CRT for at least 3 months. This systematic review was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA Statement). Following our search strategy, 47 studies were finally included in our review. CMR appears to have an additive role in identifying the subgroup of patients who will respond better to CRT. Specifically, the presence and the extent of myocardial scar were associated with increased non-response rates, while those with no scar respond better. Furthermore, existing data show that scar location can be associated with CRT response rates. CMR-derived markers of mechanical desynchrony can also be used as predictors of CRT response. CMR data can be used to optimize the position of the left ventricular lead during the CRT implantation procedure. Specifically, positioning the left ventricular lead in a branch of the coronary sinus that feeds an area with transmural scar was associated with poorer response to CRT. CMR can be used as a non-invasive optimization tool to identify patients who are more likely to achieve better clinical and echocardiographic response following CRT implantation. [Abstract copyright: © 2022. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Ανταπόκριση στη θεραπεία καρδιακού επανασυγχρονισμού σε ασθενείς με καρδιακή ανεπάρκεια που πληρούν τα κριτήρια Strauss

Εισαγωγή: Η θεραπεία καρδιακού επανασυγχρονισμού (CRT) αποδείχθηκε πολύ αποτελεσματική στη βελτίωση της νοσηρότητας και της θνησιμότητας σε ασθενείς που πάσχουν από σοβαρή καρδιακή ανεπάρκεια. Η αποτελεσματικότητά της έχει αποδειχθεί ότι είναι μεγαλύτερη σε ασθενείς με αποκλεισμό αριστερού σκέλους (LBBB). Στόχος της μελέτης μας ήταν να διερευνήσουμε εάν τα προτεινόμενα κριτήρια για το LBBB από τον Strauss εντοπίζουν ασθενείς με καλύτερη κλινική και υπερηχογραφική ανταπόκριση στη CRT. Μέθοδος: Αξιολογήσαμε μια ομάδα 48 ασθενών με συμπτωματική καρδιακή ανεπάρκεια (ισχαιμικής ή μη ισχαιμικής αιτιολογίας), παρά τη βέλτιστη φαρμακευτική θεραπεία. Τα κριτήρια ένταξης στη μελέτη ήταν LVEF ≤35% και η παρουσία LBBB με QRS ≥130 msec στο ΗΚΓ πριν από την εμφύτευση. Οι υπό μελέτη ασθενείς υποβλήθηκαν σε εμφύτευση CRT-D στο ηλεκτροφυσιολογικό μας κέντρο από τον Ιανουάριο του 2013 έως τον Δεκέμβριο του 2017.Οι ασθενείς χωρίστηκαν σε 2 ομάδες ανάλογα με το εάν εμφάνιζαν LΒΒΒ κατά Strauss ή όχι. Αποτελέσματα: Από τους 22 ασθενείς με Strauss LBBB, 20 (90,9%) ανταποκρίθηκαν στη θεραπεία με συσκευές CRT ενώ οι υπόλοιποι 2 (9,1%) ασθενείς δεν ανταποκρίθηκαν (p <0,01). Η ομάδα που δεν ανταποκρίθηκε είχε σημαντικά υψηλότερο κίνδυνο νοσηλείας (p <0,01) και κοιλιακών αρρυθμιών (p = 0,03) κατά τη διάρκεια της παρακολούθησης σε σύγκριση με τους ανταποκρινόμενους. Είναι αξιοσημείωτο ότι, ενώ η επίπτωση θνησιμότητας κατά τη διάρκεια της παρακολούθησης ήταν χαμηλή (0,04%), οι 2 ασθενείς που απεβίωσαν δεν είχαν ανταποκριθεί στη θεραπεία με CRT. Στο τέλος της παρακολούθησης, παρατηρήθηκε σημαντική αύξηση στο κλάσμα εξώθησης (αύξηση κατά 18%) και σημαντική μείωση του LVESV (74,1mm) στους ασθενείς με Strauss LBBB (p <0,001), ενώ μια σημαντική, αλλά ηπιότερη, αύξηση στο κλάσμα εξώθησης (κατά 5%) και η μείωση στο LVESV (27,6mm) παρατηρήθηκε στην ομάδα με non Strauss LBBB (p <0,001). Τέλος, στους ασθενείς με διατατική μυοκαρδιοπάθεια και Strauss LBBB  παρατηρήθηκε βελτίωση στο κλάσμα εξωθήσεως κατά 22% έναντι βελτίωσης 6% στους ασθενείς με συμβατικό LBBB (p <0,001). Συμπέρασμα: Οι ασθενείς με Strauss LBBB έχουν καλύτερη κλινική και ηχοκαρδιογραφική ανταπόκριση σε σχέση με τους ασθενείς με LBBB με τη CRT και ιδίως αυτοί που πάσχουν από διατατική μυοκαρδιοπάθεια.Background: Cardiac resynchronization therapy (CRT) has proved to be effective in improving morbidity and mortality in patients suffering from severe congestive heart failure. Its efficacy has been shown to be greater in patients with left bundle branch block (LBBB). The aim of our study was to investigate whether the proposed LBBB criteria by Strauss identify patients with a better response to CRT. Methods: We evaluated a group of 48 patients with symptomatic heart failure (ischemic or non-ischemic etiology), despite optimal drug therapy. The study inclusion criteria were LVEF ≤35% and the presence of LBBB with QRS ≥130 msec in the ECG prior to implantation. The patients under study were subjected to CRT-D implantation in our electrophysiology center from January 2013 until December 2017. Patients were divided into 2 groups depending on whether they presented Strauss LBBB or not. Results: Of the 22 Strauss LBBB patients, 20 (90.9%) responded to CRT device therapy while the remaining 2 (9.1%) patients were non-responders (p <0.01). The non-responding group had a significantly higher risk of hospitalizations (p <0.01) and ventricular arrhythmias (p =0.03) during follow-up compared to responders. Interestingly, while the incidence of mortality during follow-up was low (0.04%), the 2 patients who died were non-responders to CRT therapy. At the end of follow-up, a significant increase in ejection fraction (18% increase) and a significant decrease in LVESV (74.1) were noticed in Strauss LBBB patients (p <0.001) while a significant but quiet lower increase in ejection fraction (5%) and decrease in LVESV (27,6) were noticed in non strauss group (p <0.001). Finally, in patients with dilated cardiomyopathy and Strauss LBBB, an improvement of the ejection fraction by 22% versus 6% in patients with conventional LBBB was observed (p <0.001). Conclusion: The Strauss LBBB patients have better clinical and echocardiographic response than LBBB patients, particularly in those with dilated cardiomyopath

Predictors of ventricular arrhythmias in patients with mitral valve prolapse: A meta-analysis

Mitral valve prolapse (MVP) has an estimated prevalence of 2-3% in the general population. Patients with MVP have an increased risk of ventricular arrhythmic events. The aim of this meta-analysis was to identify easily obtained markers that can be used for the arrhythmic risk stratification of MVP patients. This meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA Statement). The search strategy identified 23 studies that were finally included in the study. The quantitative synthesis showed that late gadolinium enhancement (LGE) [RR 6.40 (2.11-19.39), I2 77%, P = 0.001], longer QTc interval [mean difference: 14.2 (8.92-19.49) I2 0%, P < 0.001], T-wave inversion in inferior leads [RR 1.60 (1.39-1.86), I2 0%, P < 0.001], mitral annular disjunction (MAD) [RR 1.77 (1.29-2.44), I2 37%, P = 0.0005], lower left ventricular ejection fraction (LVEF) [mean difference: -0.77 (-1.48, -0.07) I2 0%, P = 0.03], bileaflet MVP [RR 1.32 (1.16-1.49), I2 0%, P < 0.001], increased anterior [mean difference: 0.45 (0.28, 0.61), I2 0%, P < 0.001] and posterior [mean difference: 0.39 (0.26, 0.52), I2 0%, P < 0.001] mitral leaflet thickness were significantly associated with ventricular arrhythmias in MVP patients. On the other hand, gender, QRS duration, anterior, and posterior mitral leaflet length were not associated with increased risk of arrhythmias. In conclusion, inferior T-wave inversions, QTc interval, LGE, LVEF, MAD, bileaflet MVP, anterior, and posterior mitral leaflet thickness are easily obtained markers that can be used for the risk stratification of patients with MVP. Prospective studies should be designed for the better stratification of this population. [Abstract copyright: Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.

Predictors of ventricular arrhythmias in patients with Mitral valve prolapse: A meta-analysis.

Mitral valve prolapse (MVP) has an estimated prevalence of 2-3% in the general population. Patients with MVP have an increased risk of ventricular arrhythmic events. The aim of this meta-analysis was to identify easily obtained markers that can be used for the arrhythmic risk stratification of MVP patients. This meta-analysis was performed in accordance with the Preferred Reporting Items for Systematic Reviews and Meta-Analyses (PRISMA Statement). The search strategy identified 23 studies that were finally included in the study. The quantitative synthesis showed that late gadolinium enhancement (LGE) [RR 6.40 (2.11-19.39), I2 77%, P = 0.001], longer QTc interval [mean difference: 14.2 (8.92-19.49) I2 0%, P < 0.001], T-wave inversion in inferior leads [RR 1.60 (1.39-1.86), I2 0%, P < 0.001], mitral annular disjunction (MAD) [RR 1.77 (1.29-2.44), I2 37%, P = 0.0005], lower left ventricular ejection fraction (LVEF) [mean difference: -0.77 (-1.48, -0.07) I2 0%, P = 0.03], bileaflet MVP [RR 1.32 (1.16-1.49), I2 0%, P < 0.001], increased anterior [mean difference: 0.45 (0.28, 0.61), I2 0%, P < 0.001] and posterior [mean difference: 0.39 (0.26, 0.52), I2 0%, P < 0.001] mitral leaflet thickness were significantly associated with ventricular arrhythmias in MVP patients. On the other hand, gender, QRS duration, anterior, and posterior mitral leaflet length were not associated with increased risk of arrhythmias. In conclusion, inferior T-wave inversions, QTc interval, LGE, LVEF, MAD, bileaflet MVP, anterior, and posterior mitral leaflet thickness are easily obtained markers that can be used for the risk stratification of patients with MVP. Prospective studies should be designed for the better stratification of this population. [Abstract copyright: Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.

Cardiac contractility modulation in patients with heart failure - A review of the literature.

Experimental in vivo and in vitro studies showed that electric currents applied during the absolute refractory period can modulate cardiac contractility. In preclinical studies, cardiac contractility modulation (CCM) was found to improve calcium handling, reverse the foetal myocyte gene programming associated with heart failure (HF), and facilitate reverse remodeling. Randomized control trials and observational studies have provided evidence about the safety and efficacy of CCM in patients with HF. Clinically, CCM therapy is indicated to improve the 6-min hall walk, quality of life, and functional status of HF patients who remain symptomatic despite guideline-directed medical treatment without an indication for cardiac resynchronization therapy (CRT) and have a left ventricular ejection fraction (LVEF) ranging from 25 to 45%. Although there are promising results about the role of CCM in HF patients with preserved LVEF (HFpEF), further studies are needed to elucidate the role of CCM therapy in this population. Late gadolinium enhancement (LGE) assessment before CCM implantation has been proposed for guiding the lead placement. Furthermore, the optimal duration of CCM application needs further investigation. This review aims to present the existing evidence regarding the role of CCM therapy in HF patients and identify gaps and challenges that require further studies. [Abstract copyright: © 2024. The Author(s), under exclusive licence to Springer Science+Business Media, LLC, part of Springer Nature.

Atrial fibrillation in the setting of cardiac amyloidosis - A review of the literature.

Cardiac amyloidosis (CA) is related to the aggregation of insoluble fibrous deposits of misfolded proteins within the myocardium. Transthyretin amyloidosis (ATTR) and immunoglobulin light-chain amyloidosis are the main forms of CA. Atrial fibrillation (AF) is a common arrhythmia in CA patients, especially in those with ATTR amyloidosis. Increased atrial preload and afterload, atrial enlargement, enhanced atrial wall stress, and autonomic dysfunction are the main mechanisms of AF in CA patients. CA is associated with the formation of endocardial thrombi and systemic embolism. The promoters of thrombogenesis include endomyocardial damage, blood stasis, and hypercoagulability. The prevalence of thrombi in patients with AF remains elevated despite long-term anticoagulation. Consequently, transesophageal ultrasound examinations before cardioversion should be performed to exclude endocardiac thrombi despite anticoagulation. Furthermore, the CHA DS -VASc score should not be used to assess the thromboembolic risk in CA patients with AF. Rate control is challenging in patients with CA, while rhythm control is the preferred treatment option, especially in the early stages of the disease process. Although catheter ablation is an effective treatment option, more data are needed to explore the role of the procedure in CA patients. [Abstract copyright: Copyright © 2024. Published by Elsevier Ltd.

Atrial fibrillation and Wolff–Parkinson–White syndrome: A double blow for the cardiologist

Abstract Electrocardiographic findings including irregularity of the rhythm, a very rapid ventricular response, and the presence of a delta wave should raise the suspicion of pre‐excited atrial fibrillation with a rapid ventricular response. Urgent cardioversion is needed due to the risk of sudden cardiac death

Cardiac contractility modulation in patients with heart failure — A review of the literature

Experimental in vivo and in vitro studies showed that electric currents applied during the absolute refractory period can modulate cardiac contractility. In preclinical studies, cardiac contractility modulation (CCM) was found to improve calcium handling, reverse the foetal myocyte gene programming associated with heart failure (HF), and facilitate reverse remodeling. Randomized control trials and observational studies have provided evidence about the safety and efficacy of CCM in patients with HF. Clinically, CCM therapy is indicated to improve the 6-min hall walk, quality of life, and functional status of HF patients who remain symptomatic despite guideline-directed medical treatment without an indication for cardiac resynchronization therapy (CRT) and have a left ventricular ejection fraction (LVEF) ranging from 25 to 45%. Although there are promising results about the role of CCM in HF patients with preserved LVEF (HFpEF), further studies are needed to elucidate the role of CCM therapy in this population. Late gadolinium enhancement (LGE) assessment before CCM implantation has been proposed for guiding the lead placement. Furthermore, the optimal duration of CCM application needs further investigation. This review aims to present the existing evidence regarding the role of CCM therapy in HF patients and identify gaps and challenges that require further studies

The role of electrophysiological study in the risk stratification of Brugada Syndrome

Brugada syndrome (BrS) is a complex arrhythmogenic disease associated with an increased risk of sudden cardiac death (SCD). The role of electrophysiological study (EPS) for risk stratification purposes of asymptomatic BrS patients remains still controversial. This study aims to summarize the existing data about the role of electrophysiological study for arrhythmic risk stratification of BrS patients without a prior history of aborted SCD or fatal arrhythmic event. Two independent investigators (G.B. and G.T.) performed a systematic search in the MedLine database and Cochrane library from their inception until April 2022 without any limitations. The reference lists of the relevant research studies as well as the relevant review studies and meta-analyses were manually searched. Nineteen studies were included in the final analysis. The included studies enrolled 6218 BrS patients (mean age: 46.9 years old, males: 76%) while 4265 (68.6%) patients underwent an EPS. The quantitative synthesis showed that a positive EPS study was significantly associated with arrhythmic events in BrS patients (RR, 1.74 [1.23-2.45]; P = 0.002; I2 = 63%]. By including the studies that provided data on the association of EPS with arrhythmic events during follow-up in patients without a prior history of aborted SCD or fatal arrhythmic event, the association between positive EPS study and future arrhythmic events remained significant (RR, 1.60 [1.08-2.36]; P = 0.02; I2 = 19%). In conclusion, EPS is a useful invasive tool for the risk stratification of BrS patients and can be used to identify the population of BrS patients who may be candidates for primary prevention of SCD with implantable cardioverter-defibrillator (ICD) implantation. [Abstract copyright: Copyright © 2023 Wolters Kluwer Health, Inc. All rights reserved.