430 Diagnosis and management of a case of biventricular arrhythmogenic cardiomyopathy: a case report

Arrhythmogenic cardiomyopathy (ACM) is a genetically determined heart muscle disorder characterized by fibro-fatty replacement of myocardium which may affect the right ventricle (‘dominant right’ variant), the left ventricle (‘dominant left’ variant) or both (‘biventricular disease’ variant). Despite of ACM is one of the main causes of sudden cardiac death (SCD) in young people and athletes as well, the diagnosis of this complex clinical entity still remains a challenge. We report on a case of a 29 years old non-athletic woman with family history of SCD and a long-standing personal history of palpitations leading to frequent accesses to the Accident & Emergency Department. Her echocardiogram was normal while twelve leads ECG revealed negative T waves in the right precordial leads (V1–V3) and post-excitation epsilon waves. ECG Holter monitoring recorded frequent (up to 17 000 in 24 h) polymorphic premature ventricular contractions (PVCs) seldom organized in couplets or triplets. She was followed-up in our clinic and started on Propanolol 40 mg bid with slight relief of symptoms and reduction of PVCs. Cardiac magnetic resonance (CMR) showed regional dyskinesia of both ventricles and RV dilatation. Moreover, tissue characterization findings revealed the presence of diffuse subepicardial late gadolinium enhancement (LGE) of the LV. Genetic analysis was performed and a variant of uncertain significance (VUS) in Desmoplakin was identified. Non sustained monomorphic ventricular tachycardia was induced during electrophysiologic study by programmed ventricular stimulation. In light of these results, we diagnosed biventricular ACM and, after carefully discussion with the patient, a subcutaneous implantable cardioverter defibrillator (ICD) was implanted. The present case should be a persisting reminder that must be considered more than just a single diagnostic tool when dealing with arrhythmic presentations especially in young patients and the importance of contrast CMR along with genetic testing in order to aid clinicians in the demanding selection of the best candidates for ICD implantation.

Administration of Adenosine Triphosphate Provides Additional Value Over Programmed Electrophysiologic Study in Confirmation of Successful Ablation of Atrioventricular Accessory Pathways

Objectives: To study the benefit of adenosine triphosphate (ATP) in evaluating ablation endpoints of accessory pathways (AP) and subsequent long-term prognosis.Methods: We reviewed consecutive patients with supraventricular tachycardias due to APs that underwent radiofrequency catheter ablation (RFCA) from January 2016 to September 2018 in our center. The patients were divided into two groups: the ATP group (who had passed both the ATP test and PES after ablation as the endpoint) and the non-ATP group (who had passed PES only after ablation as the endpoint). We reviewed the patients' intra-cardiac electrograms and analyzed their long-term outcomes.Results: In total, 1,343 patients underwent successful RFCA. There were 215 patients in the ATP group with one lost to follow-up. There were 1,128 patients in the non-ATP group with 39 lost to follow-up. Twenty-three patients in the ATP group demonstrated additional electrophysiological entities due to ATP administration, including reappearance of the ablated APs in 16 patients, discovery of PES-undetected APs in 5, induction of atrial fibrillation in 5, premature atrial contractions in 1, and premature ventricular contractions in another. During the 7 to 39 months (average 24.4 ± 9.5 months) follow-up, the recurrence rate was 8.41% (18/214) in the ATP group and 6.80% (74/1,084) in the non-ATP group. In subjects with recurrence, 14 patients (14/18 = 77.8%) in the ATP group and 50 patients (50/74 = 67.6%) in the non-ATP group accepted redo ablations. Among the ATP-group, all the 14 redo APs were the old ones as before. Among the non-ATP-group, redo ablations confirmed that 39 APs were the old ones, while 20 APs were newly detected ones which had been missed previously. The difference in recurrent AP locations confirmed by redo procedures between the two groups was significant (p = 0.008). In the non-ATP group, 20 (40%) of redo cases were proven to have multiple APs, while 33 (3.3%) cases who did not suffer from recurrence had multiple APs. Existences of multiple APs in recurred cases were significantly higher than that in non-recurred ones in the non-ATP group (p < 0.001), while there was no such difference in the ATP group (p = 0.114).Conclusions: The existence of multiple APs was more common in recurrent cases if ATP was not used for confirmation of ablation endpoints. ATP probably has additional value over PES alone by detecting weak AP conductions. ATP can evoke atrial and ventricular arrhythmias.

Takotsubo syndrome presenting with syncope and third-degree atrioventricular block requiring permanent pacemaker implantation

Takotsubo syndrome (TS) is an acute but transient heart failure syndrome and it is very uncommon for TS to present as syncope with complete atrioventricular (AV)block.In this report,we aimed to present a case of TS complicated by third-degree AV block presented to the emergency department with syncope and requiring permanent pacemaker implantation.A 53-year-old female admitted to our emergency department with complaints of syncopal episodes and chest pain.Due to ongoing chest pain,electrocardiography (ECG) findings and segmentary wall motion abnormality on the transthoracic echocardiography (TTE),she was immediately transferred to cardiac catheterization laboratory.Coronary angiogram revealed normal coronary arteries and left ventriculography demonstrated apical ballooning and hypokinesis of the apex.As the diagnosis of TS was established,patient was transferred to coronary intensive care unit(CICU).Initial ECG at CICU demonstrated complete AV block with a heart rate of 35 beats/min.On third day of hospitalization,repeat TTE showed improved left ventricular functions with an ejection fraction of 50%.During the follow-up period in CICU,complete AV block persisted and the rhythm did not return to normal sinus rhythm after 6 days of monitorization.An electrophysiologic study demonstrated supra-hisian atrioventricular block and atrioventricular dissociation.On seventh day of hospitalization,TTE demonstrated recovered ventricular functions with an ejection fraction of 65% and a dual pacemaker was then implanted.Her third month follow-up was uneventful and TTE showed normal left ventricular functions but pacemaker interrogation revealed 99% of ventricular pacing.This case report demonstrated that,the decision to implant a permanent pacemaker on such patients should be considered on a case-by-case basis,and electrophysiologic study could be valuable on this decision.

Differences in ventricular tachycardia inducibility in patients with Tetralogy of Fallot depending on the clinical indication for the electrophysiologic study

Introduction The arrhythmic risk stratification of patients with repaired Tetralogy of Fallot (TOF) is still controversial. The performance of an electrophysiologic (EP) study before pulmonary valve replacement (PVR), regardless of patient's risk factors, is an extended practice in some centers that is not recommended in current guidelines. The aim of our study was to explore the differences in ventricular tachycardia (VT) inducibility in patients with TOF during programmed ventricular stimulation (PVS) depending on the clinical indication. Methods All patients with repaired TOF who underwent an EP study with PVS between January 2001 and October 2020 were included. EP studies performed in the context of ventricular or supraventricular tachycardia ablations that had been previously diagnosed were excluded. We defined two clinical scenarios for performing the EP study: pre-PVR (performed previous to pulmonary valve replacement) or diagnostic EP study (performed due to high risk symptoms which included palpitations, syncope or presyncope). Baseline clinical information, electrocardiogram, echocardiogram and cardiac MRI parameters were retrospective recorded. Results A total of 139 EP studies with PVS were included; 87 in the pre-PVR group and 52 in the diagnostic EP study group. There was a greater incidence of palpitations, syncope and presyncope in the “Diagnostic EP study” group. Moreover, there were statistical significant differences in right ventricle dimensions and function between groups. The repair surgical approach was similar in both groups. It was detected a statistical significant difference in VT induction between the pre-PVR group and the diagnostic indicated group (16,1% vs 34,6%, p=0,012). Conclusions Differences in VT induction are observed during PVS performing in TOF patients depending on the clinical indication. Symptomatology is an important parameter that must be taken into account in order to decide whether to perform an EP study in this population. FUNDunding Acknowledgement Type of funding sources: None.

Identifying the Location of an Accessory Pathway in Pre-Excitation Syndromes Using an Artificial Intelligence-Based Algorithm

(1) Background: The exact anatomic localization of the accessory pathway (AP) in patients with Wolff–Parkinson–White (WPW) syndrome still relies on an invasive electrophysiologic study, which has its own inherent risks. Determining the AP localization using a 12-lead ECG circumvents this risk but is of limited diagnostic accuracy. We developed and validated an artificial intelligence-based algorithm (location of accessory pathway artificial intelligence (locAP AI)) using a neural network to identify the AP location in WPW syndrome patients based on the delta-wave polarity in the 12-lead ECG. (2) Methods: The study included 357 consecutive WPW syndrome patients who underwent successful catheter ablation at our institution. Delta-wave polarity was assessed by four independent electrophysiologists, unaware of the site of successful catheter ablation. LocAP AI was trained and internally validated in 357 patients to identify the correct AP location among 14 possible locations. The AP location was also determined using three established tree-based, ECG-based algorithms (Arruda, Milstein, and Fitzpatrick), which provide limited resolutions of 10, 5, and 8 AP locations, respectively. (3) Results: LocAP AI identified the correct AP location with an accuracy of 85.7% (95% CI 79.6–90.5, p < 0.0001). The algorithms by Arruda, Milstein, and Fitzpatrick yielded a predictive accuracy of 53.2%, 65.6%, and 44.7%, respectively. At comparable resolutions, the locAP AI achieved a predictive accuracy of 95.0%, 94.9%, and 95.6%, respectively (p < 0.001 for differences). (4) Conclusions: Our AI-based algorithm provided excellent accuracy in predicting the correct AP location. Remarkably, this accuracy is achieved at an even higher resolution of possible anatomical locations compared to established tree-based algorithms.

Intra-Carpal Injection of Ozone versus Methylprednisolone in Carpal Tunnel Syndrome of Systemic Sclerosis Patients: A Randomized Single-Blind Clinical Trial

BACKGROUND: Carpal tunnel syndrome (CTS) is the most entrapment syndrome in general and is the most frequent peripheral nervous system involvement in systemic sclerosis (SSc). Local injection of steroid hydrodissection or ozone-oxygen showed favourable outcome in CTS in general. OBJECTIVES: To compare the clinical efficacy of ozone versus methylprednisolone intracarpal injection upon pain, functional status, and nerve conduction in patients with CTS due to SSc. STUDY DESIGN: A randomized single-blinded trial. SETTING: Anesthesia, pain, and rheumatology clinics in a university hospital. METHODS: Fifty CTS patients with > 3 months duration of SSc were equally randomized into either group O (injection of ozone/oxygen 25 mu-g/mL in 20 mL) or group M (methylprednisolone acetate 40mg, and 40 mg lidocaine in 20 mL). Visual analog scale (VAS) was measured pre-injection, then re-evaluated post-injection at 4 time points (1 week, 1 month, 3 months , and 6 months); Cochin Hand Function Scale (CHFS); and a median nerve electrophysiologic study was done before injection, then by the end of 3 months and 6 months. RESULTS: VAS was significantly lower in group M after 1 week (P = 0.01). Group O showed significantly lower VAS after 3 and 6 month (P < 0.001). Additionally, there was a significant decrease in the VAS during the whole study period within each group, in comparison to its baseline value. CHFS was significantly lower in the ozone group after 6 months (P < 0.001). The sixth month’s sensory conduction was significantly higher in group O (P = 0.002). The motor distal latency was significantly lower in the ozone group after 3 and 6 months (P < 0.001). LIMITATIONS: Follow-up period could be furtherly extended. CONCLUSION: Both intracarpal ozone or methylprednisolone afford favorable effects upon CTS in patients with SSc. However, ozone alleviates pain much more, enhances the hand functional status, and improves median nerve conduction in study with over six months duration. KEY WORDS: Carpal Tunnel Syndrome, systemic sclerosis, methylprednisolone, ozone

Hidden under the Surface: A Rare Cause of Repeated Syncope in a Patient with Recent Pacemaker Implantation

A 66-year-old woman received a pacemaker implantation because of syncope with documented sinus arrest and junctional bradycardia. Three weeks later the pacemaker analysis revealed episodes of nonsustained ventricular tachycardia. Coronary angiography and invasive coronary assessment showed diffuse moderate stenosis but no significant ischemia. Three months later she experienced a new syncope and the pacemaker analysis showed runs of nonsustained ventricular tachycardia at the time of syncope. The combination of brady- and tachyarrhythmias raised concern for cardiac sarcoidosis. 18F-fluorodeoxyglucose positron emission tomography (PET) scan showed increased FDG uptake in the basal segments compatible with inflammatory disease. Cardiac magnetic resonance imaging showed late gadolinium enhancement in the same region of the PET-avid lesions. Diagnostic electrophysiologic study could induce VT. The diagnosis of cardiac sarcoidosis was made, for which high dose corticosteroids were prescribed and an upgrade to a dual chamber implantable cardioverter defibrillator was performed. Because of the localization of the lesions, an endomyocardial biopsy was not performed. All the lesions regressed completely on PET-scan after treatment with high dose corticosteroids.