Unlocking the enigma: decoding premature ventricular complexes for effective clinical assessment and risk management.

The identification of ventricular premature complexes during a cardiological evaluation necessitates the implementation of diagnostic processes aimed at discerning the clinical context that may predispose individuals to a high risk of sudden cardiac death. Epidemiological studies reveal that ventricular premature beats occur in approximately 75% of healthy (or seemingly healthy) individuals, as long as there is no evidence of underlying structural heart disease, such as benign idiopathic ventricular extrasystole originating from the right and left ventricular outflow tracts. In the real world, however, ventricular ectopic beats with morphologies very similar to seemingly benign occurrences are not uncommon. They are notable in subjects exhibiting rapid and complex repetitive forms during exercise testing and Holter electrocardiogram. Additionally, these subjects may display more or less extensive scarring signs on cardiac magnetic resonance and may have a family history of cardiomyopathy and/or sudden cardiac death. Therefore, the purpose of this review is to critically analyse the process of evaluating premature ventricular complexes, which is crucial for accurate risk stratification. The latter cannot overlook some inevitable elements, including morphology, origin, complexity, and the associated clinical setting (absence or presence of structural heart disease).

Electrocardiographic characteristics of right-bundle-branch-block premature ventricular complexes predicting absence of left ventricular scar in athletes with apparently structural normal heart.

AIMS: Left ventricular scar is an arrhythmic substrate that may be missed by echocardiography and diagnosed only by cardiac magnetic resonance (CMR), which is a time-consuming and expensive imaging modality. Premature ventricular complexes (PVCs) with a right-bundle-branch-block (RBBB) pattern are independent predictors of late gadolinium enhancement (LGE) but their positive predictive value is low. We studied which electrocardiographic features of PVCs with an RBBB pattern are associated with a higher probability of the absence of an underlying LGE. METHODS: The study included 121 athletes (36 ± 16 years; 48.8% men) with monomorphic PVCs with an RBBB configuration and normal standard clinical investigations who underwent CMR. LGE was identified in 35 patients (29%), predominantly in those with PVCs with a superior/intermediate axis (SA-IntA) compared to inferior axis (IA) (38% vs. 10%, P = 0.002). Among patients with SA-IntA morphology, the contemporary presence of qR pattern in lead aVR and V1 was exclusively found in patients without LGE at CMR (51.0% vs. 0%, P < 0.0001). Among patients with IA, the absence of LGE correlated to a narrow ectopic QRS (145 ± 16 vs. 184 ± 27 msec, P < 0.001). CONCLUSIONS: Among athletes with apparently idiopathic PVCs with a RBBB configuration, the presence of a concealed LGE at CMR was documented in 29% of cases, mostly in those with a SA-IntA. In our experience, the contemporary presence of qR pattern in lead aVR and V1 in PVCs with RBBB/SA-IntA morphology or, on the other hand, a relatively narrow QRS in PVCs with an IA, predicted absence of LGE.

Intermittent ventricular pre-excitation in symptomatic adults: Always a marker of low risk?

BACKGROUND: Intermittent ventricular pre-excitation was considered a low-risk marker for sudden death. However, to date, some studies do not exclude the existence of accessory pathways (APs) with high-risk intermittent antegrade conductive properties. According to current European Guidelines, high-risk features of APs are antegrade pathway conduction ≤250 ms in baseline or during the adrenergic stimulus, inducibility of atrioventricular reciprocating tachycardias (AVRT), inducibility of pre-excited atrial fibrillation (AF), and presence of multiple APs. For all of these transcatheter ablation is recommended. The aim of our study was to evaluate the existence of differences in risk characteristics between patients with intermittent pre-excitation (IPX) and those with persistent pre-excitation (PPX), from a sample of adults with ventricular pre-excitation and symptoms like palpitations. METHODS: 293 adults [IPX: 51 (17.4%); PPX: 242 (82.6%)] underwent electrophysiological study and then catheter ablation of their APs if arrhythmia inducibility (AVRT/AF) was noted, or, conversely, if it was appreciated a fast AP antegrade conduction, in baseline or during intravenous isoproterenol infusion, or if multiple APs were detected. RESULTS: There were no statistically significant differences in demographic characteristics (age and gender), AVRT/AF inducibility, antegrade conductive properties, the prevalence of multiple APs, and APs locations between IPX and PPX patients. CONCLUSIONS: In our study, patients with IPX did not show significant differences in clinical and electrophysiological features versus PPX patients.

The implantable cardiac monitor in heart failure patient: a possible new indication?

Implantable cardiac monitors (ICMs) have found increasing use in clinical practice over the years, proving, when used in high-risk populations, to facilitate the diagnosis of bradyarrhythmias and tachyarrhythmias requiring treatment. Experience with heart failure patients undergoing pacemaker (PMK) or implantable defibrillator (ICD) implantation, which allow for continuous electrocardiographic monitoring and transthoracic impedance assessment, has made it possible to identify predictors of heart failure flare-ups. In this context, the use of telemonitoring has been shown to ensure better management of patients with heart failure. These benefits cannot be assessed to date in patients with heart failure and left ventricular ejection fraction (LVEF) > 35% who have no indication for PMK or ICD implantation. This population has been shown to have a significant incidence of ventricular arrhythmias and bradyarrhythmias. In addition, a significant number of cerebrovascular events are observed in this population, largely attributable to the high incidence of atrial fibrillation (AF). In this population, the occurrence of AF has also been shown to have a negative impact on patients' prognosis; at the same time, a rhythm control strategy has been shown to be more beneficial in this area than a rate control strategy. Studies also suggest arrhythmias have a negative impact on the cognitive status and quality of life of heart failure patients. These reasons could justify the implantation of ICMs equipped with telemonitoring systems in heart failure patients. The information provided by the monitoring system, if properly managed, could bring benefits in terms of prognosis and quality of life along with a reduction in economic costs. We will try here, by answering a few questions, to assess whether there is an indication for ICM in heart failure, which patients should be candidates and how these patients should be managed.

MR guided cardiac ablation: how to build an interventional magnetic resonance suite and what's the role of the imaging.

Magnetic resonance (MR) represents a new interesting imaging approach for guiding electrophysiology (EP)-based ablation procedures of atrial flutter and typical atrial fibrillation. This new approach permits to reach good results if compared with conventional EP ablation. Tissue characterization by MR permits to detect cardiac anatomy and pathological substrate like myocardial scars well visualized with late gadolinium enhancement (LGE) sequences. Intra-procedural imaging is useful to real-time follow the catheter during the ablation procedure and at the same time to visualize cardiac anatomy in addition to understanding if the ablation is correctly performed using oedema sequences. Performing cardiac ablations inside an MR room permits to reduce radiation exposure and occupational illnesses.

Pacing of the specialized His-Purkinje conduction system: 'back to the future'.

The conduction system of the human heart is composed of specialized cardiomyocytes that initiate and propagate the electric impulse with consequent rhythmic and synchronized contraction of the atria and ventricles, resulting in the normal cardiac cycle. Although the His-Purkinje system (HPS) was already described more than a century ago, there has been a recent resurgence of conduction system pacing (CSP), where pacing leads are positioned in the His bundle region and left bundle branch area to provide physiological cardiac activation as alternatives to the unnatural myocardial stimulation obtained with conventional right ventricular and biventricular pacing. In this review, we describe the fundamental anatomical and pathophysiological aspects of the specialized HPS along with the CSP technique's nuts and bolts to highlight its potential benefits in everyday clinical practice.

Cardiac magnetic resonance-guided cardiac ablation: a case series of an early experience.

Radiofrequency (RF) catheter ablation has become a widely used therapeutic approach. However, long-term results in terms of arrhythmia recurrence are still suboptimal. Cardiac magnetic resonance (CMR) could offer a valuable tool to overcome this limitation, with the possibility of targeting the arrhythmic substrate and evaluating the location, depth, and possible gaps of RF lesions. Moreover, real-time CMR-guided procedures offer a radiation-free approach with an evaluation of anatomical structures, substrates, RF lesions, and possible complications during a single procedure. The first steps in the field have been made with cavotricuspid isthmus ablation, showing similar procedural duration and success rate to standard fluoroscopy-guided procedures, while allowing visualization of anatomic structures and RF lesions. These promising results open the path for further studies in the context of more complex arrhythmias, like atrial fibrillation and ventricular tachycardias. Of note, setting up an interventional CMR (iCMR) centre requires safety and technical standards, mostly related to the need for CMR-compatible equipment and medical staff's educational training. For the cardiac imagers, it is fundamental to provide correct CMR sequences for catheter tracking and guide RF delivery. At the same time, the electrophysiologist needs a rapid interpretation of CMR images during the procedures. The aim of this paper is first to review the logistic and technical aspects of setting up an iCMR suite. Then, we will describe the experience in iCMR-guided flutter ablations of two European centres, Policlinico Casilino in Rome, Italy, and Haga Teaching Hospital in The Hague, the Netherlands.

Atrial fibrillation and sympatho-vagal imbalance: from the choice of the antiarrhythmic treatment to patients with syncope and ganglionated plexi ablation.

For several years, the autonomic nervous system has played a central role in the pathophysiological mechanism of atrial fibrillation (AF), so much so that it has been considered one of the cornerstones of Coumel's triangle. The clinical and therapeutic management of AF secondary to sympatho-vagal imbalance represents one of the most important examples of how precision medicine should be applied. Increasing knowledge of this kind of arrhythmias has made it possible to select specific antiarrhythmic drugs and to diversify their use according to vagal or adrenergic AF forms. Ablative strategies, such as cardioneuroablation and non-direct cardiac neuromodulation methods (such as renal denervation and peripheral vagal stimulation), have gradually emerged. In the possibly near future, there will be a development of new acquisitions regarding new pharmacological therapeutic strategies and gene therapy. Finally, finding an AF in patients experiencing syncopal episodes opens a whole chapter regarding interesting, but also complex, diagnostic and therapeutic strategies, ranging from neurally mediated forms to convulsive seizure that could also increase the risk of sudden death.

The value of the 12-lead electrocardiogram in the prediction of sudden cardiac death.

Sudden cardiac death (SCD) can be caused by several clinical conditions, overt or misconceived, which recognize different pathophysiologies determining the development of fatal arrhythmic events. In the various forms of structural heart disease such as ischaemic heart disease, cardiomyopathies (e.g. hypertrophic cardiomyopathy, dilated cardiomyopathy, and arrhythmogenic cardiomyopathy), channelopathies (e.g. long-QT syndrome, congenital short QT, Brugada syndrome, early repolarization (ER) syndrome, and idiopathic ventricular fibrillation) but also in the apparently healthy subject, the 12-lead electrocardiogram (ECG) has proved, over the years, to be a reliable and readily available method for stratifying the risk of adverse arrhythmic events and consequently SCD. Several electrocardiographic markers have been shown to be associated with adverse outcomes in different types of patients. Although with different sensitivity and specificity in each clinical condition, depolarization abnormalities, such as QRS fragmentation, Q waves, QRS duration, left posterior fascicular block, low QRS voltage, and left ventricular hypertrophy and similarly repolarization abnormalities as ER pattern, T wave alternans, QT interval, and QT dispersion, have shown significant efficacy in predicting SCD. Despite the advancement of techniques especially in the field of imaging, the correct interpretation of the 12-lead ECG remains, therefore, an effective tool for assessing the possible prognostic outcome in terms of arrhythmic risk and SCD in different types of patients.

Ganglionated plexi ablation in the right atrium for the treatment of cardioinhibitory syncope.

Neurocardiogenic syncope, also called vasovagal syncope, represents one of the clinical manifestations of neurally mediated syncopal syndrome. Generally, the prognosis of the cardioinhibitory form of neurocardiogenic syncope is good, but quality of life is seriously compromised in patients who experience severe forms. Drug therapy has not achieved good clinical results and very heterogeneous data come from studies regarding permanent cardiac pacing. In this scenario, the ganglionated plexi ablation has been proposed as an effective and safe method in patients with cardioinhibitory neurocardiogenic syncope, especially in young patients in order to avoid or prolong, as much as possible, the timing of definitive cardiac pacing. Certainly, making this procedure less extensive and limiting the ablation in the right atrium (avoiding the potential complications of a left atrial approach) and at level of anatomical regions of the most important ganglionated plexy, considered 'gateway' of the sino-atrial and atrio-ventricular node function (through the recognition of specific endocardial potentials), could be very advantageous in this clinical scenario. Finally, randomized, multicentre, clinical trials on a large population are needed to better understand which is the best ablation treatment (right-only or bi-atrial) and provide evidence for syncope guidelines.

Tissue thickness measured with dielectric-based technology during radiofrequency catheter ablation.

Radiofrequency catheter ablation of the cavotricuspid isthmus is the standard treatment for patients suffering from typical atrial flutter. The aim of this study was to test the feasibility of tissue thickness and lesion transmurality measurement by a novel dielectric system. This was a retrospective multicentric non-randomized open-label, single-arm study. The atrial wall thickness was significantly higher close to the tricuspid annulus than close to the inferior vena cava and a trend towards a progressive decrease of atrial wall thickness was observed moving the mapping catheter from the tricuspid valve to the inferior vena cava. The possibility to visualize the tissue thickness could modify the way to deliver radiofrequency energy, allowing a tailored approach in cardiac ablation procedures.

Electrocardiogram in arrhytmogenic cardiomyopathy.

Criteria for diagnosis of arrhythmogenic cardiomyopathy (ACM) were first proposed in 1994 and subsequently revised in 2010 and in 2020 by an international task force. According to the last consensus of 2020, ACM is defined as a heart muscle disease affecting right ventricle, left ventricle or both, whose principal pathologic feature is fibrofatty myocardial replacement that impairs systolic ventricular function and predisposes to lethal ventricular arrhythmias. ECG findings not only could help to early recognize affected patients but also could identify the ones with maximum risk of ventricular arrhythmias and sudden cardiac death.

Heart failure and telemedicine: where are we and where are we going? Opportunities and critical issues.

Heart failure (HF) is one of the main causes of morbidity in the world and is responsible for an enormous amount of health costs, mostly due to hospitalizations. The remote control techniques of vital signs and health status have the potential to help prevent factors leading to HF instability by stimulating early therapeutic interventions. The goal of telemedicine is to change the intervention strategy from a 'reactive' type, in which therapy is optimized in response to the worsening of symptoms, to a 'pro-active' type, in which therapeutic changes are undertaken based on changes in the monitored parameters during the sub-clinical phase. This article is aimed at exploring the major results obtained by telemedicine application in HF patients with and without cardiac electronic devices or in those with haemodynamic sensors and to analyse the critical issues and the opportunities of its use.

The electrocardiogram in non-ischaemic-dilated cardiomyopathy.

This article summarizes the main electrocardiogram (ECG) findings in dilated cardiomyopathy (DCM) patients. Recent reports are described in the great 'pot' of DCM peculiar ECG patterns that are typical of specific forms of DCM. Patients with late gadolinium enhancement on CMR, who are at greatest arrhythmic risk, have also distinctive ECG features. Future studies in large DCM populations should evaluate the diagnostic and prognostic value of the ECG.

Safety, efficacy, and reproducibility of cavotricuspid isthmus ablation guided by the ablation index: acute results of the FLAI study.

AIMS: Ablation index (AI) is a marker of lesion quality during catheter ablation that incorporates contact force, time, and power in a weighted formula. This index was originally developed for pulmonary vein isolation as well as other left atrial procedures. The aim of our study is to evaluate the feasibility and efficacy of the AI for the ablation of the cavotricuspid isthmus (CTI) in patients presenting with typical atrial flutter (AFL). METHODS AND RESULTS: This prospective multicentre non-randomized study enrolled 412 consecutive patients with typical AFL undergoing AI-guided cavotricuspid isthmus ablation. The procedure was performed targeting an AI of 500 and an inter-lesion distance measurement of ≤6 mm. The primary endpoints were CTI 'first-pass' block and persistent block after a 20-min waiting time. Secondary endpoints included procedural and radiofrequency duration and fluoroscopic time. A total of 412 consecutive patients were enrolled in 31 centres (mean age 64.9 ± 9.8; 72.1% males and 27.7% with structural heart disease). The CTI bidirectional 'first-pass' block was reached in 355 patients (88.3%), whereas CTI block at the end of the waiting time was achieved in 405 patients (98.3%). Mean procedural, radiofrequency, and fluoroscopic time were 56.5 ± 28.1, 7.8 ± 4.8, and 1.9 ± 4.8 min, respectively. There were no major procedural complications. There was no significant inter-operator variability in the ability to achieve any of the primary endpoints. CONCLUSION: AI-guided ablation with an inter-lesion distance ≤6 mm represents an effective, safe, and highly reproducible strategy to achieve bidirectional block in the treatment of typical AFL.

Impact of His bundle pacing on right ventricular performance in patients undergoing permanent pacemaker implantation.

BACKGROUND: His-Bundle pacing (HBP) is an emerging technique for physiological pacing. However, its effects on right ventricle (RV) performance are still unknown. METHODS: We enrolled consecutive patients with an indication for pacemaker (PM) implantation to compare HBP versus RV pacing (RVP) effects on RV performance. Patients were evaluated before implantation and after 6 months by a transthoracic echocardiogram. RESULTS: A total of 84 patients (age 75.1±7.9 years, 64% male) were enrolled, 42 patients (50%) underwent successful HBP, and 42 patients (50%) apical RVP. At follow up, we found a significant improvement in RV-FAC (Fractional Area Change)% [baseline: HBP 34 IQR (31-37) vs. RVP 33 IQR (29.7-37.2),p = .602; 6-months: HBP 37 IQR (33-39) vs. RVP 30 IQR (27.7-35), p < .0001] and RV-GLS (Global Longitudinal Strain)% [baseline: HBP -18 IQR (-20.2 to -15) vs. RVP -16 IQR (-18.7 to -14), p = .150; 6-months: HBP -20 IQR(-23 to -17) vs. RVP -13.5 IQR (-16 to -11), p < .0001] with HBP whereas RVP was associated with a significant decline in both parameters. RVP was also associated with a significant worsening of tricuspid annular plane systolic excursion (TAPSE) (p < .0001) and S wave velocity (p < .0001) at follow up. Conversely from RVP, HBP significantly improved pulmonary artery systolic pressure (PASP) [baseline: HBP 38 IQR (32-42) mmHg vs. RVP 34 IQR (31.5-37) mmHg,p = .060; 6-months: HBP 32 IQR (26-38) mmHg vs. RVP 39 IQR (36-41) mmHg, p < .0001] and tricuspid regurgitation (p = .005) irrespectively from lead position above or below the tricuspid valve. CONCLUSIONS: In patients undergoing PM implantation, HBP ensues a beneficial and protective impact on RV performance compared with RVP.

Reproducibility of pulmonary vein isolation guided by the ablation index: 1-year outcome of the AIR registry.

BACKGROUND: Ablation index (AI) is a new lesion quality marker that has been demonstrated to allow a high single-procedure arrhythmia-free survival in single-center studies. This prospective, multi-center study was designed to evaluate the reproducibility of pulmonary vein (PV) isolation guided by the AI. METHODS: A total of 490 consecutive patients with paroxysmal (80.4%) and persistent AF underwent first time PV isolation and were divided in four study groups according to operator's preference in choosing the ablation catheter (a contact force (ST) or contact force surround flow (STSF) catheter) and the AI setting (330-450 or 380-500 at anterior wall or posterior wall, respectively). RESULTS: At 12 months a high rate of freedom from AF recurrences was observed in patients with both paroxysmal and persistent AF (91% vs 83.3%; P = .039). There was no difference in the rate of AF recurrence among the four study groups (4.5% in group ST330-450, 12.2% in group ST 380-500, 14.9% in group STSF330-450, 9.4% in group STSF380-500; P = .083). Recurrence was also similar between patients treated with a ST (8%) or STSF catheter (12.1%; P = .2), and within patients targeting an AI settings of 330 to 450 (10.9%) or 380 to 500 (10.3%; P = .64). In patients with paroxysmal AF, there was no difference (P = .12) in the 1-year freedom from AF recurrence among 14 operators that performed ≥10 ablation procedure. CONCLUSIONS: An ablation protocol respecting strict criteria for contiguity and quality lesion resulted in high rate of 1-year freedom from AF recurrence, irrespective of the ablation catheters, AI settings, and operator.

Trends beyond the new normal: from remote monitoring to digital connectivity.

COVID pandemic emergency has forced changes from traditional in-person visits to application of telemedicine in order to overcome the barriers and to deliver care. COVID-19 has accelerated adoption of digital health. During this time, the distance is itself a prevention tool and the use of technology to deliver healthcare services and information has driven the discovery of mobile and connected health services. Health services should to be prepared to integrate the old model of remote monitoring of CIEDs and adopt new digital tools such as mobile Apps and connected sensors.

Contact-force monitoring increases accuracy of right ventricular voltage mapping avoiding "false scar" detection in patients with no evidence of structural heart disease.

PURPOSE: Electroanatomical mapping (EAM) could increase cardiac magnetic resonance imaging (CMR) sensitivity in detecting ventricular scar. Possible bias may be scar over-estimation due to inadequate tissue contact. Aim of the study is to evaluate contact-force monitoring influence during EAM, in patients with idiopathic right ventricular arrhythmias. METHODS: 20 pts (13 M; 43 ± 12 y) with idiopathic right ventricular outflow tract (RVOT) arrhythmias and no structural abnormalities were submitted to Smarttouch catheter Carto3 EAM. Native maps included points collected without considering contact-force. EAM scar was defined as area ≥1 cm2 including at least 3 adjacent points with signal amplitude (bipolar <0.5 mV, unipolar 3,5 mV), surrounded by low-voltage border zone. EAM were re-evaluated offline, removing points collected with contact force <5 g. Finally, contact force-corrected maps were compared to the native ones. RESULTS: An EAM was created for each patient (345 ± 85 points). After removing poor contact points, a mean of 149 ± 60 points was collected. The percentage of false scar, collected during contact force blinded mapping compared to total volume, was 6.0 ± 5.2% for bipolar scar and 7.1 ± 5.9% for unipolar scar, respectively. No EAM scar was present after poor contact points removal. Right ventricular areas analysis revealed a greater number of points with contact force < 5 g acquired in free wall, where reduced mean bipolar and unipolar voltage were recorded. CONCLUSIONS: To date this is the first work conducted on structurally normal hearts in which contact-force significantly increases EAM accuracy, avoiding "false scar" related to non-adequate contact between catheter and tissue.

Reproducibility of acute pulmonary vein isolation guided by the ablation index.

BACKGROUND: Atrial fibrillation (AF) ablation outcome is still operator dependent. Ablation Index (AI) is a new lesion quality marker that has been demonstrated to allow acute durable pulmonary vein (PV) isolation followed by a high single-procedure arrhythmia-free survival. This prospective, multicenter study was designed to evaluate the reproducibility of acute PV isolation guided by the AI. METHODS: A total of 490 consecutive patients with paroxysmal (80.4%) and persistent AF underwent first time PV encircling and were divided in four study groups according to operator preference in choosing the ablation catheter (a contact force [ST] or contact force surround flow [STSF] catheter) and the AI setting (330 at posterior and 450 at anterior wall or 380 at posterior and 500 at anterior wall). Radiofrequency was delivered targeting interlesion distance ≤6 mm. RESULTS: The rate of first-pass PV isolation (ST330 90 ± 16%, ST380 87 ± 19%, STSF330 90 ± 17%, STSF380 91 ± 15%, P = .585) was similar among the four study groups, whereas procedure (ST330 129 ± 44 minutes, ST380 144 ± 44 minutes, STSF330 120 ± 72 minutes, STSF380 125 ± 73 minutes, P < .001) and fluoroscopy time (ST330 542 ± 285 seconds, ST380 540 ± 416 seconds, STSF330 257 ± 356 seconds, STSF380 379 ± 454 seconds, P < 0.001) significantly differed. The difference in the rate of first-pass isolation was not statistical different (P = .06) among the 12 operators that performed at least 15 procedures. CONCLUSIONS: An ablation protocol respecting strict criteria for contiguity and quality lesion results in high and comparable rate of acute PV isolation among operator performing ablation with different catheters, AI settings, procedure, and fluoroscopy times.