Brugada syndrome in Iran: Insights from a 12-year longitudinal study.

BACKGROUND: Brugada syndrome (BrS) is characterized by ST-segment elevation in the right precordial leads, which is not explained by ischemia, electrolyte disturbances, or obvious structural heart disease. AIM: In present study, we aim to evaluate presentation, long-term outcome, genetic findings, and therapeutic interventions in patients with BrS. METHODS: Between September 2001 and June 2022, all consecutive patients with diagnosis of BrS were enrolled in the present study. All patients gave written informed consent for the procedure, and the local ethical committee approved the study. RESULTS: Of the 76 cases, 79% were proband and 21% were detected during screening after diagnosis of BrS in a family member. Thirty-three (43%) patients had a typical spontaneous electrocardiogram (ECG) pattern. Thirty percent of the patients were symptomatic; symptomatic patients were more likely to have spontaneous type 1 Brugada ECG pattern in their ECGs (p = .01), longer PR interval (p = .03), and SCN5A mutation (p = .01) than asymptomatic patients. The mean PR interval was considerably longer in men than women (p = .034). SCN5A mutation was found in 9 out of 50 (18%) studied patients. Fifteen percent received appropriate implantable cardioverter-defibrillator (ICD) therapy and inappropriate ICD interventions were observed in 17%. Presentation with aborted SCD or arrhythmic syncope was the only predictor of adverse outcome in follow-up (odds ratio: 3.1, 95% confidence interval: 0.7-19.6, p = .001). CONCLUSIONS: Symptomatic patients with BrS are more likely to present with spontaneous type 1 Brugada ECG pattern, longer PR interval, and pathogenic mutation in SCN5A gene. Appropriate ICD interventions are more likely in symptomatic patients and those with SCN5A mutation.

Electrical storm following pregnancy in systemic scleroderma: A case report.

INTRODUCTION: Systemic sclerosis (SSc) is a rare connective tissue disease characterized by immune dysfunction, vascular damage, and fibrosis affecting the skin and multiple internal organs, such as the cardiovascular and respiratory systems. In some women with preexisting SSc, pregnancy is associated with negative maternal outcomes. Tachyarrhythmia is a common clinical manifestation of cardiovascular damage in SSc patients. However, few studies have reported the use of catheter ablation and an implantable cardioverter defibrillator (ICD) in patients with SSc complicated by ventricular tachycardia (VT). CASE: A 19-year-old woman known case of SSc referred to our center with recurrent VT during pregnancy and after delivery. Two-dimensional Echocardiogram showed severe systolic dysfunction with a left ventricular ejection fraction (LVEF) of 30%. Considering, recurrent VT despite medical treatment and the progressive nature of systemic sclerosis radiofrequency catheter (RF) ablation and ICD implantation were performed. CONCLUSION: We report a case of systemic sclerosis complicated by VT and left ventricular (LV) dysfunction during pregnancy that was successfully treated with RF ablation.

Comparison of de novo implantation vs. upgrade cardiac resynchronisation therapy: a multicentre experience.

BACKGROUND: The clinical safety and consequences of upgrade procedures compared with de novo cardiac resynchronisation therapy (CRT) implantation in heart failure remain unclear. The present study aimed to assess clinical and procedural consequences of patients undergoing CRT upgrade as compared to de novo CRT implantations. METHODS: In this prospective cohort study, two subgroups were considered as the study population as (1) de novo group that CRT was considered on optimised medical treatment with heart failure of NYHA functional class from II to IV, left ventricular ejection fraction (LVEF) of ≤35%, and QRS width of >130 ms and (2) upgrade group including the patients with previously implantable cardioverter defibrillator (ICD) with the indications for upgrading to CRT. The two groups were compared regarding the changes in clinical outcome and echocardiography parameters. RESULTS: The procedure was successful in 95.9% of patients who underwent CRT upgrade and 100% of those who underwent de novo CRT implantation. It showed a significant improvement in LVEF, severity of mitral regurgitation and NYHA functional classification, without any difference between the two study groups. Overall procedural related complications were reported in 10.8% and 3.8% (p = .093) and cardiac death in 5.4% and 2.5% (p = .360), respectively, with no overall difference in postoperative outcome between the two groups. CONCLUSIONS: Upgrading to CRT is a safe and effective procedure regarding improvement of functional class, left ventricular function status and post-procedural outcome.

Clinical outcomes of subcutaneous implantable cardiac defibrillator implantation - Iran SICD registry.

BACKGROUND: The subcutaneous implantable-defibrillator (S-ICD) is a relatively new alternative to the transvenous ICD system to minimize intravascular lead-related complications. This paper presents outcome of SICD implantation in patients enrolled in Iran S-ICD registry. METHODS: Between October 2015 and June 2022, this prospective multicenter national registry included 223 patients with a standard indication for an ICD, who neither required bradycardia pacing nor needed cardiac resynchronization to evaluate the early post-implant complications and long-term follow-up results of the S-ICD system. RESULTS: The mean age of the patients was 45 ± 17 years. The majority (79.4%) were male. Ischemic cardiomyopathy (39.5%) was the most common underlying disorder among patients selected for S-ICD implant. Most study patients (68.6%) had ICD for primary prevention of sudden cardiac death. Seven patients (3.1%) were found to have suboptimal lead positions. Six patients (2.7%) developed a pocket hematoma; all were managed medically. During a mean follow-up of 2 years, the appropriate therapy was recorded in 13% of the patients and inappropriate ICD intervention mainly due to supraventricular tachycardia in 8.9%. Pocket infection was observed in four patients (1.8%) and five patients (2.2%) died mainly due to heart failure. CONCLUSION: S-ICDs were effective at detecting and treating both induced and spontaneous ventricular arrhythmias. Major clinical complications were rare.

A survival analysis of bipolar steroid-eluting and unipolar nonsteroid-eluting epicardial leads.

INTRODUCTION: Epicardial pacemakers are known as an alternative for endocardial pacemakers in some cases such as heart block, and complex congenital heart diseases. Considering recent advances and improvement of epicardial lead subtypes, it is essential to investigate the long-term function of them. In this study, we aimed to assess the sensing and pacing characteristics, and survival of bipolar steroid-eluting and unipolar nonsteroid-eluting epicardial pacemakers. METHODS: We conducted an entirely concentrated search on the documents of all patients who had undergone epicardial lead implantation in the Shaheed Rajaie Cardiovascular, Medical & Research Center during 2015-2018. Implant, and follow-up data were extracted. Kaplan-Meier analysis and Weibull regression hazards model were applied for the survival analysis. RESULTS: Eighty-nine leads were implanted for 77 patients. Of the total leads, 52.81%, 53.93%, and 47.19% were implanted in children (under 18-year-old), females, and patients with congenital heart diseases, respectively. Bipolar steroid-eluting leads comprised 33.71% of 89 leads. The pacing threshold of unipolar nonsteroid-eluting leads that were implanted on the left ventricle and right atrium increased significantly during the follow-up to greater records than bipolar steroid-eluting leads. Survival analysis also revealed that bipolar steroid-eluting leads are significantly better in 48-month survival (Weibull hazard ratio [HR]: 0.13 (95% confidence interval [CI]: 0.02-0.99), p = .049). Age, ventricular location of the lead, and acute pacing characteristics were not associated with survival. CONCLUSIONS: Bipolar steroid-eluting epicardial leads have an acceptable survival compared with unipolar nonsteroid-eluting, without a significant difference regarding patients age. Therefore, they could be an excellent alternative for endocardial ones.

A Comprehensive Review of Left Ventricular Summit Ventricular Arrhythmias.

The catheter ablation of idiopathic ventricular arrhythmias is accepted as a first-line treatment as it successfully eliminates about 90.0% of such arrhythmias. One of the most challenging ventricular arrhythmias originates from the left ventricular summit (LVS), a triangular epicardial space with the left main bifurcation as its apex. This area accounts for about 14.0% of LV arrhythmias. The complex anatomy of this region, accompanied by proximity to the major epicardial coronary arteries and the presence of a thick fat pad in this region, renders it a challenging area for catheter ablation. This article presents a review of the anatomy of the LVS and relevant regions and discusses novel mapping and ablation techniques for eliminating LVS ventricular arrhythmias. Additionally, we elaborate on the electrocardiographic (ECG) manifestations of arrhythmias from the LVS and their successful ablation via the direct approach and the adjacent structures.

A prospective survey of atrial fibrillation management in Iran: Baseline results of the Iranian Registry of Atrial Fibrillation (IRAF).

BACKGROUND: Atrial fibrillation. (AF) is the most common sustained arrhythmia globally and its prevalence is likely to increase in the next decades as a result of increasing age and co-morbidities. There are no data on demographic features, clinical characteristics, associated comorbidities, and practice patterns of AF in Iran. METHODS: The Iranian Registry of Atrial Fibrillation (IRAF) is a hospital-based prospective survey of AF patients with a 12-month follow-up. Data were collected on a standardized case report form and entered into a web-based electronic database. This paper reports the baseline characteristics of the IRAF cohort. RESULTS: Between February 2018 and March 2020, a total of 1300 patients (57% Male, mean age, 60 ± 14 years) were enrolled. Palpitations were the most common presenting symptom (66%). The most common cardiac comorbidities were hypertension (52%), heart failure (23.7%), and valvular heart disease (21.8%). AF mainly presented as a paroxysmal pattern (44.6%). Seventy-eight percent of the patients with non-valvular AF had CHA2 DS2 -VASc score ≥1 and most (97%) were at low risk for bleeding (HAS-BLED score <3). Rhythm control was given to 55.1% of the patients. Anticoagulation for stroke prevention was provided to 69.5% of the eligible patients, while aspirin was used in 35%. CONCLUSION: The IRAF Registry has provided a systematic collection of contemporary data regarding the management and treatment of AF in Iran. Oral anticoagulant was used in 69.5%, but aspirin use was still common.

Proximal coronary sinus pacing induced prolonged asystole.

BACKGROUND: Atrioventricular node (AVN) is an interatrial septum structure located at the apex of triangle of Koch that modulates the transmission of impulses from atria to the ventricles. Vagally mediated AVN block with high frequency stimulation (HFS) was investigated in a few animal and human studies, but prolonged ventricular asystole that was induced by a low frequency proximal coronary sinus (CS) overdrive pacing has rarely been reported. CASE REPORT: A 40-year-old man was admitted in our hospital for evaluation of syncope and palpitation. He presented with prolonged ventricular asystole by proximal CS pacing during electrophysiological study (EPS). CONCLUSION: There is no comprehensive clinical study to investigate the association of vasovagal syncope with vagally mediated atrioventricular block (AVB) which is induced by posteroseptal area stimulation. Radiofrequency catheter ablation of ganglionated plexi (GP) located close to sinus node and AVN was reported to eliminate the vagal efferent output during vasovagal syncope as a new treatment strategy.

Catheter ablation of an antidromic atrioventricular reentrant tachycardia using a slow, decrementally conducting accessory pathway in the great cardiac vein.

The inability to ablate left accessory pathways (APs) from endocardial approaches may suggest an epicardial location. We report on a 43-year-old woman presenting with a wide QRS tachycardia with Right Bundle Branch Block (RBBB) morphology, right inferior axis, and the "pattern break" appearance in V2 resembled the outflow tract ventricular tachycardia. An electrophysiology study confirmed an antidromic atrioventricular reentrant tachycardia using an antegrade slow, decrementally conducting AP that was successfully ablated in the great cardiac vein-anterior interventricular vein junction after failure of endocardial approach.

Cryoballoon ablation results and complications in mid-term follow-up of patients with atrial fibrillation.

BACKGROUND: Atrial fibrillation (AF) is the most common cardiac arrhythmia, and its prevalence increases with advancing age. Pulmonary vein isolation is a standard approach in drug refractory paroxysmal AF which could be performed by cryoballoon ablation (CBA). We tried to evaluate its efficacy and safety in Iranian patients with AF. METHODS: From 2015 to 2017, 97 patients with paroxysmal and persistent AF were enrolled in our observational historical cohort study. They were visited 1 and 6 months post-procedure in order to assess the efficacy (recurrence) and safety. Recurrence was defined as 30 seconds of arrhythmia on their 48-hours Holter monitoring. RESULTS: Ninety-seven patients enrolled in the study, 64 (66.0%) of them were men, and their mean age was 55 ± 12 years. Hypertension was reported in 41 patients (42.3%), as the most common cardiac risk factor. 71 patients (73.2%) patients with paroxysmal AF and 15 patients (15.5%) with persistent AF underwent the procedure. After 6 months, recurrence was documented in only 17 patients (17.5%), and 82.5% of the patients were free from the recurrence. Post-procedural complication was detected only in 3 patients (3.1%). CONCLUSION: In our study, the mid-term success and safety of CBA in patients with paroxysmal AF was showed. CBA is a safe and effective method in paroxysmal AF, and even in some cases with persistent AF.