In 3 similar cases of supraventricular tachycardia, rhythm presented the same conversion mode. In 1 case, tachycardia was terminated with atrial activation, while entrainment maneuvers during an electrophysiology study revealed the same response and diagnosis in all 3 cases. What is the most likely underlying mechanism of these tachycardias?

Background Right phrenic nerve (PN) injury is a major complication of thermal ablation of atrial tachycardias (ATs) originated from the superior vena cava (SVC).Case summary We report the case of a 41-year-old female patient admitted for catheter ablation of a frequent paroxysmal AT resistant to antiarrhythmic drugs. Electroanatomical activation map demonstrated a focal origin located at the lateral aspect of the SVC, similar to 17 mm above the breakthrough of the sinus node wavefront. Importantly, high-output pacing from this site resulted in PN capture. To avoid PN injury, low-output radiofrequency (RF) ablation, with a power output limited to 20 W, was performed. However, this approach was insufficient to terminate AT. High-power RF applications in proximity to the PN were avoided and pulsed-field ablation (PFA) with a pentaspline catheter was chosen. The catheter was advanced into the SVC to the level of the earliest activation under fluoroscopic guidance and visualization within the mapping system. Two pairs of applications, in basket configuration, were delivered inside the SVC, rendering AT non-inducible while sinus node function was not compromised.Discussion Phrenic nerve is vulnerable to injury during ablation within the SVC using thermal ablation modalities. Low-output RF ablation may be safe but less efficient. In contrast, non-thermal approaches such as PFA may be preferable to avoid damage to the collateral tissues as PN. Electroanatomical mapping may be important to avoid lesions in proximity to the sinus node.

Background Cavotricuspid isthmus pulsed-field ablation has been recently described to be safely performed despite initial reports on coronary arterial spasm while conduction disturbances as a complication of cavotricuspid isthmus ablation are rare and have been reported exclusively for radiofrequency catheter ablation. Case summary A 64-year-old female patient with mechanical prosthetic valves underwent atrial fibrillation ablation using the pentaspline pulsed-field ablation catheter. At the end of the uneventful pulmonary vein isolation, an atrial tachycardia depended to the cavotricuspid isthmus occurred. A single pulsed-field application at the cavotricuspid isthmus resulted in right bundle branch block combined with posterior fascicular hemiblock and PR prolongation that resolved spontaneously within 12 h. Discussion This is the first report of transient conduction disturbances as a complication of cavotricuspid isthmus pulsed-field ablation. Although the underlying mechanism, either single or miscellaneous, was not verified, this case highlights that caution should be taken when the pentaspline pulsed-field ablation catheter is used for cavotricuspid isthmus ablation.

1.A high prevalence of arrhythmias is observed after heart surgeries (as for excisions of myxomas), related to the anatomical substrate of the atriotomy scars, requiring catheter ablation.2.Surgical injury to the cardiac conduction system should also be considered in these patients as conduction disturbances may occur after cardiac interventions requiring the implantation of a pacemaker.3.Although pacemaker syndrome has mainly been described in VVIR-paced patients and sinus rhythm, it can also be presented with atrial-based pacing due to interatrial conduction disturbances.

Cardiac magnetic resonance (CMR) imaging could enable major advantages when guiding in real-time cardiac electrophysiology procedures offering high-resolution anatomy, arrhythmia substrate, and ablation lesion visualization in the absence of ionizing radiation. Over the last decade, technologies and platforms for performing electrophysiology procedures in a CMR environment have been developed. However, performing procedures outside the conventional fluoroscopic laboratory posed technical, practical and safety concerns. The development of magnetic resonance imaging compatible ablation systems, the recording of high-quality electrograms despite significant electromagnetic interference and reliable methods for catheter visualization and lesion assessment are the main limiting factors. The first human reports, in order to establish a procedural workflow, have rationally focused on the relatively simple typical atrial flutter ablation and have shown that CMR-guided cavotricuspid isthmus ablation represents a valid alternative to conventional ablation. Potential expansion to other more complex arrhythmias, especially ventricular tachycardia and atrial fibrillation, would be of essential impact, taking into consideration the widespread use of substrate-based strategies. Importantly, all limitations need to be solved before application of CMR-guided ablation in a broad clinical setting.

Key Teaching Points•The approach to supraventricular tachycardia diagnosis has mainly been described for tachycardias with a stable cycle length. However, extrapolation of criteria derived from regular tachycardias can also be performed with caution to regularly irregular tachycardias.•When there are variations in cycle length, if V-V interval changes precede and predict A-A interval changes, then a diagnosis of atrioventricular nodal reentrant tachycardia (AVNRT) can be made.•Cycle length alternans may be seen in AVNRT in case of anterograde conduction alternating between 2 slow pathways. •The approach to supraventricular tachycardia diagnosis has mainly been described for tachycardias with a stable cycle length. However, extrapolation of criteria derived from regular tachycardias can also be performed with caution to regularly irregular tachycardias.•When there are variations in cycle length, if V-V interval changes precede and predict A-A interval changes, then a diagnosis of atrioventricular nodal reentrant tachycardia (AVNRT) can be made.•Cycle length alternans may be seen in AVNRT in case of anterograde conduction alternating between 2 slow pathways.

IntroductionOutcomes of catheter ablation for non-paroxysmal atrial fibrillation (AF) remain suboptimal. Non-invasive stratification of patients based on the presence of atrial cardiomyopathy (ACM) could allow to identify the best responders to pulmonary vein isolation (PVI).MethodsObservational multicentre retrospective study in patients undergoing cryoballoon-PVI for non-paroxysmal AF. The duration of amplified P-wave (APW) was measured from a digitally recorded 12-lead electrocardiogram during the procedure. If patients were in AF, direct-current cardioversion was performed to allow APW measurement in sinus rhythm. An APW cut-off of 150 ms was used to identify patients with significant ACM. We assessed freedom from arrhythmia recurrence at long-term follow-up in patients with APW ≥ 150 ms vs. APW < 150 ms.ResultsWe included 295 patients (mean age 62.3 ± 10.6), of whom 193 (65.4%) suffered from persistent AF and the remaining 102 (34.6%) from long-standing persistent AF. One-hundred-forty-two patients (50.2%) experienced arrhythmia recurrence during a mean follow-up of 793 ± 604 days. Patients with APW ≥ 150 ms had a significantly higher recurrence rate post ablation compared to those with APW < 150 ms (57.0% vs. 41.6%; log-rank p < 0.001). On a multivariable Cox-regression analysis, APW≥150 ms was the only independent predictor of arrhythmia recurrence post ablation (HR 2.03 CI95% 1.28–3.21; p = 0.002).ConclusionAPW duration predicts arrhythmia recurrence post cryoballoon-PVI in persistent and long-standing persistent AF. An APW cut-off of 150 ms allows to identify patients with significant ACM who have worse outcomes post PVI. Analysis of APW represents an easy, non-invasive and highly reproducible diagnostic tool which allows to identify patients who are the most likely to benefit from PVI-only approach.

Transfemoral access has been established as the gold standard approach for the majority of patients undergoing transcatheter aortic valve implantation (TAVI). However, in cases with anatomical difficulties or severely diffused peripheral arterial disease, alternative vascular access may be considered such as the transaxillary approach. We present the case of a 92-year-old gentleman with exertional dyspnea due to severe symptomatic aortic stenosis and a history of peripheral femoro-femoral bypass surgery, coronary arterial bypass surgery and a permanent dual-chamber left-side implanted pacemaker. Due to the high surgical risk and the severe anatomical difficulties, the method of TAVI using the left axillary approach was opted. A 14-F vascular sheath was inserted with surgical cutdown and with fluoroscopic guidance while small injections of contrast confirmed the non-occlusive position and the patency of the left internal mammary artery (LIMA) graft. A stiff guidewire was used to cross the heavily calcified aortic valve and subsequently was placed into the left ventricle. Balloon aortic valvuloplasty was performed followed by a successful TAVI with no significant aortic regurgitation or paravalvular leak. The patient recuperated uneventfully and was discharged after 72 h. Axillary access for TAVI is a feasible option for high-risk patients with extended peripheral arteriopathy. To our knowledge this is the first case report describing the implantation of a newer type of intra-annular self-expanding valve platform in a nonagenarian patient with severe comorbidities and such a remarkable history of multiple previous interventions in the selected access site. Meticulous upfront strategy planning and efficient collaboration between specialties is of outmost importance in hybrid procedures for favorable clinical outcomes, especially in cases with challenging anatomies.

Objective: Atrial fibrillation (AF) remains one of the major causes of cardiovascular morbidity. Ablation techniques are becoming more appealing after latest results of andomised trials showing the overall clinical benefit. On the other hand imaging techniques and the frontier application of 3D printing are emerging as valuable ally for cardiac procedures. However, no andomised trial has directly assessed the impact of preprocedural imaging and especially 3D printing guidance for AF ablation. The present study is designed to investigate for the first time the effect of 3D-printing of the heart on the safety and effectiveness of the ablation procedure. Design and method: The 3D-GALA trial is a andomised, open- label, controlled, multicentre clinical trial of 2 parallel groups designed to enrol a total of 100 patients undergoing ablation using cryo-balloon for paroxysmal and persistent AF. Patients will be andomised with a patient allocation ratio of 1: 1 to preprocedural MRI scan of the heart and 3D printing of left atrium and pulmonary veins and cryoablation versus standard cryoablation without imaging. Patients will be followed up to 6 months after the index procedure Results: The primary outcome measure is the reduction of radiation dose and contrast amount during pulmonary veins isolation. Secondary endpoints will include the percentage of atrial fibrillation relapse at 24h-Holter electrocardiogram monitoring at 6 months after initial treatment. Conclusions: To our knowledge, the 3D-GALA trial will be the first study to provide evidence about the clinical impact of preprocedural imaging and 3D printing before cryoablation.

A 64-year-old man with ischaemic cardiomyopathy, cardiac resynchronization therapy with defibrillator and previous ventricular tachycardia (VT) ablation presented due to electrical storm (ES) and recurrent discharges from the device. He was under mexiletine and carvedilol, as he discontinued amiodarone due to thyrotoxicosis. Intravenous esmolol and xylocaine, reprogramming of the device and general anaesthesia mildly reduced VT episodes and shocks. Left stellate ganglion blockade (LSGB) with continuous infusion of 0.2% ropivacaine terminated ES without completely ending VT events (five episodes in following 7 days). Considering the response to LSGB, cryoneurolysis (CRYO-S Painless, Metrum) of the left stellate ganglion (LSG) was attempted with ultrasound guidance to achieve long-term autonomic modulation (Figure). The needle was inserted at the C6 level to reach the prevertebral fascia on the top of Longus Colli muscle and one cryoapplication of 3 min was delivered (−78°C). No procedural complications were observed except transient Horner syndrome. Patient...

Amyloid light-chain (AL) amyloidosis is a multisystemic disease. Among its clinical manifestations, vein and arterial thromboembolic events are included. We report the unusual case of a 57-year-old female patient with AL amyloidosis presenting with an ST segment elevation myocardial infarction due to coronary artery embolization (CE). The patient reported a history of exertional dyspnoea along with episodes of haemoptysis for the last few months. Her coronary angiography demonstrated embolization of the distal segment of the left anterior descending artery. The main findings of her cardiac ultrasound included concentric left ventricular hypertrophy, mildly impaired left ventricular systolic function, left atrium enlargement and a restrictive-like filling pattern, while her chest computed tomography (CT) demonstrated bilateral pleural effusions. Cardiac magnetic resonance imaging that was performed afterwards, indicated areas of microvascular infarction, a small apex infarct and findings compatible with possible amyloidosis, a diagnosis that was confirmed later by fat tissue biopsy. Patient was referred for an oncology consultation, started therapy with direct oral anticoagulants, angiotensin converting enzyme inhibitor, statins and anti-plasma cell therapy. She has been improving since then and has been free of cardiovascular events for a follow-up period of 12 months. Cardiologists ought to be aware of amyloidosis as a rare but possible cause of coronary embolization, while close collaboration with oncologists is required for the establishment of the correct diagnosis.

Background: Chemotherapy regimens for breast cancer treatment can promote vascular dysfunction and lead to high cardiovascular risk. Purpose: To investigate the cardiovascular burden and vascular inflammation in metastatic breast cancer patients receiving CDK 4/6 inhibitors or everolimus in addition to standard hormonal treatment. Methods: 22 consecutive female patients with metastatic breast cancer were enrolled. Relative wall thickness (RWT) and left ventricle mass (LVM) measurements by transthoracic echocardiography were obtained followed by 24-h ambulatory blood pressure monitoring, and 18F-fluorodeoxyglucose positron-emission tomography/computed tomography imaging. Uptake of the radiotracer in the aortic wall was estimated as tissue-to-background ratio (TBR). Each patient was assessed for the aforementioned parameters before the initiation and after 6 months of treatment. Results: At follow up, patients assigned to CDK 4/6 treatment demonstrated increased 24-h systolic blood pressure (SBP) (p = 0.004), daytime SBP (p = 0.004) and night time SBP (p = 0.012) (Group effect). The 24-h mean arterial pressure measurements were also higher in CDK 4/6 population, in comparison to everolimus that displayed firm values (Group effect- p = 0.035, Interaction effect-p = 0.023). Additionally, 24 h diastolic blood pressure recordings in CDK 4/6 therapy were higher opposed to everolimus that remained consistent (Interaction effect- p = 0.010). In CDK 4/6 group, TBR aorta also increased significantly, whereas TBR values in everolimus remained stable (Interaction effect-p = 0.049). Both therapeutic regimens displayed statistically significant damaging effect to RWT and LVM. Conclusion: CDK 4/6 inhibitors and hormonal treatment can lead to increased vascular inflammation, and higher blood pressure compared to the combination of everolimus and hormonal treatment. Moreover, both treatment strategies promoted left ventricle remodeling.

Background Electroanatomic mapping is usually required in order to obtain a precise diagnosis and guide the ablation of atrial tachycardias (ATs) after ablation for atrial fibrillation (AF). However, epicardial connections may limit the interpretation of the endocardial activation sequence as well as the efficacy of endocardial radiofrequency ablation. Case summary A 53-year-old man with history of AF ablation 2 years ago was admitted for ablation of a recurrent AT (cycle length 275 ms). Ultra-high-density mapping with the Rhythmia (TM) system revealed a challenging activation map with two focal points of early activation in the left atrium. The use of an advanced mapping software allowed the rapid reanalysis and reannotation of the activation map and suggested epicardial involvement of the Marshall bundle (MB). Subsequent ethanol infusion in the vein of Marshall (VOM) immediately terminated the tachycardia. Six months post-ablation, the patient had no recurrence of arrhythmias. Discussion This case highlights the role of novel diagnostic and treatment methods in the management of a post-AF ablation AT. By developments in cardiac mapping systems, the rapid editing of a high-density activation map and clarification of the arrhythmia origin can be facilitated overcoming the limitations of conventional techniques. Moreover, ethanol infusion in the VOM was shown to be an effective alternative method in the management of MB-related tachycardias.

Inflammation and coagulation pathways are implicated in circulatory disease, but their interaction has not been completely deciphered yet. In this study, we investigated the association of coagulation and inflammation indices (activated clotting time [ACT], C-reactive protein, neutrophils) in hospitalized patients. Blood samples were drawn from consecutive patients at admission and at 48 hours for the assessment of the aforementioned parameters (n = 63). Healthy controls matched for sex and age were also examined (n = 39). Activated clotting time positively correlated with CRP on admission ( r = 0.354, P = .005), while the correlation was more robust on the second day ( r = 0.775, P < .001). Activated clotting time was significantly more prolonged in patients with abnormal CRP or abnormal absolute neutrophil count compared to patients with normal inflammatory markers ( U = 55.0, P < .001 and U = 310.5, P = .035, respectively). At 48 hours, a positive relationship was observed between ACT and relative percentage of neutrophils ( r = 0.358, P = .004). These findings suggest a link between ACT and inflammation indices for the first time in humans. Further research is needed to determine whether these interrelations can be used to improve patient management.

An increased incidence of maternal cardiac arrhythmias is observed during pregnancy and is possibly associated with the physiologic changes that occur in the cardiovascular system. However, new onset ventricular arrhythmias are usually idiopathic and benign while life-threatening rhythm disorders are exceedingly rare. The latter are usually presented in patients with structural heart diseases or inherited primary arrhythmia syndromes emphasizing the importance of a comprehensive evaluation. Although management of ventricular arrhythmias in pregnancy is generally similar to that in non-pregnant patients, adverse effects of the medical treatment to the fetus should be considered.

A 60-year-old patient presented with recalcitrant electrical storm (ES). Mild sedation and initial antiarrhythmic combination of esmolol and amiodarone did not affect the intensity of ES, which resulted in battery exhaustion. Oral propranolol in addition to intravenous amiodarone might be preferred in hemodynamically stable patients before interventional therapies. (Level of Difficulty: Intermediate.)