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.

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.

Myocardial Perfusion SPECT Imaging Radiomic Features and Machine Learning Algorithms for Cardiac Contractile Pattern Recognition.

A U-shaped contraction pattern was shown to be associated with a better Cardiac resynchronization therapy (CRT) response. The main goal of this study is to automatically recognize left ventricular contractile patterns using machine learning algorithms trained on conventional quantitative features (ConQuaFea) and radiomic features extracted from Gated single-photon emission computed tomography myocardial perfusion imaging (GSPECT MPI). Among 98 patients with standard resting GSPECT MPI included in this study, 29 received CRT therapy and 69 did not (also had CRT inclusion criteria but did not receive treatment yet at the time of data collection, or refused treatment). A total of 69 non-CRT patients were employed for training, and the 29 were employed for testing. The models were built utilizing features from three distinct feature sets (ConQuaFea, radiomics, and ConQuaFea + radiomics (combined)), which were chosen using Recursive feature elimination (RFE) feature selection (FS), and then trained using seven different machine learning (ML) classifiers. In addition, CRT outcome prediction was assessed by different treatment inclusion criteria as the study's final phase. The MLP classifier had the highest performance among ConQuaFea models (AUC, SEN, SPE = 0.80, 0.85, 0.76). RF achieved the best performance in terms of AUC, SEN, and SPE with values of 0.65, 0.62, and 0.68, respectively, among radiomic models. GB and RF approaches achieved the best AUC, SEN, and SPE values of 0.78, 0.92, and 0.63 and 0.74, 0.93, and 0.56, respectively, among the combined models. A promising outcome was obtained when using radiomic and ConQuaFea from GSPECT MPI to detect left ventricular contractile patterns by machine learning.

Electrophysiological and therapeutic effects of amiodarone in patients with preexcited atrial fibrillation.

Background: Atrial fibrillation (AF) with fast ventricular response over an overt accessory pathway (AP) (preexcited AF) with a short anterograde refractory period is a potentially malignant arrhythmia. This study aimed to evaluate the safety and efficacy of amiodarone for preexcited AF management. Materials and Methods: This study enrolled 103 patients with evidence of AP in electrocardiography. Patients with preexcited AF were included in the study. Intravenous amiodarone (300 mg) was infused for 30 min for all patients in the AF rhythm. Electrophysiological parameters were evaluated before amiodarone injection and 2 h after pharmacological or electrical cardioversion. Results: Antegrade and retrograde refractory periods of the atrioventricular node (AVN) and AP, as well as antegrade and retrograde Wenckebach points of AVN, were increased significantly after amiodarone infusion. Furthermore, the mean of the shortest preexcited RR interval was increased during the monitoring period. Comparing the preexcited index at the beginning of the study and before cardioversion (2 h later) revealed that the QRS complexes changed to a wider pattern as the preexcitation index changed from 80.61 to 92.26 (P < 0.001). Nineteen (18.4%) patients converted to the sinus rhythm with amiodarone infusion. No ventricular arrhythmia was detected during monitoring. Conclusion: Amiodarone could be considered a safe drug in patients with preexcited AF for rate control despite its relatively low efficacy in conversion to the sinus rhythm.

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.

Postoperative antibiotic prophylaxis in the prevention of cardiac implantable electronic device infection.

BACKGROUND: The aim of the present study was to determine whether postprocedural antibiotic reduces the risk of infection related to the cardiac implantable electronic device (CIED) implantations. METHODS: The present investigation is a randomized, prospective, single-blinded controlled trial. All consecutive patients who presented for new CIED implantation, generator replacement, or upgrade were randomized into the following three groups: (A) no antibiotic, (B) intravenous (IV) antibiotic for 1 day, (C) 1 day IV plus 7 days oral antibiotic. Follow-up was performed on 10-12 days; 1, 3, 6 months; and then every 6 months for 2 years. The primary endpoint was any evidence of infection at the generator pocket or systemic infection related to the procedure at short-term (6-month) and long-term (2-year) follow-ups. RESULTS: Of the 450 patients (72 patients with cardiac resynchronization device) included in the study, the primary endpoint of short-term infection was reached in one patient (0.2%) in group A and no patients in groups B and C. The endpoint of long-term infection was reached in nine patients (2%) with equal frequency between three randomized groups (three patients in each group). On multivariable analysis, the only independent predictor of infection was defibrillator implantation (odds ratio, 8.5; 95% confidence interval, 1.6-45). CONCLUSIONS: The results of this prospective study showed no benefit for the postoperative antibiotic for the prevention of CIED infection.

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.

An Intracardiac Mass in a Pregnant Woman Presenting With Ventricular Tachycardia.

A pregnant patient presented with symptomatic ventricular tachycardia. Echocardiography revealed a large intramyocardial mass. Surgical resection was attempted in conjunction with cryoablation of the surrounding myocardial tissue. Histologic examination of the resected mass revealed cardiac neurofibroma. To the best of our knowledge, this is the first report of cardiac neurofibroma in a pregnant patient in the absence of any neurocutaneous syndromes such as neurofibromatosis.

Doppler-derived strain and strain rate imaging assessment of right ventricular systolic function in adults late after tetralogy of Fallot repair: an observational study.

OBJECTIVE: Tetralogy of Fallot (TOF) is the most common form of cyanotic congenital heart disease. Today, we are faced with an increasing number of patients with residual pulmonary regurgitation (PR) late after TOF repair. The right ventricular (RV) volumes and function are among the most important factors influencing clinical decision-making. Cardiac magnetic resonance (CMR) is the gold standard method for the quantitative assessment of the RV function; it is, however, expensive for routine clinical follow-up and sometimes is contraindicated. We sought to evaluate the RV systolic function via CMR and compare it with Doppler-derived strain(S) and strain rate (SR) imaging in patients with repaired TOF. METHODS: In an observational cross-sectional study, 70 patients (22 women, mean age=22±4.9 years) late after TOF repair with severe PR were evaluated. Peak systolic strain and SR in the basal, mid, and apical segments of RV free wall (RVFW) were measured and compared with the RV function measured in the short-axis cine MR. Associations between RVEF and S/SR, investigated by ordinal logistic regression models. RESULTS: Significant association was observed between RV function and mean S of all the three segments of the RVFW segments [OR (CI95%): 1.17 (1.05-1.31)]. Association between RV function and mean SR of all the three segments of the RVFW segments was borderline significant [OR (CI95%): 1.7 (0.97-2.93)]. CONCLUSION: There was a significant correlation between the Doppler-derived mean strain of RVFW and the RV function measured by CMR in adults late after TOF repair. These quantitative methods improved the assessment of the RV function and served as an additional method to follow up patients with contraindications to CMR.

Recombinant λ bacteriophage displaying nanobody towards third domain of HER-2 epitope inhibits proliferation of breast carcinoma SKBR-3 cell line.

Phage display of many nanobodies via filamentous phage in combination with helper phage has been reported by many scientists. The aim of this study was to produce lambda (λ) bacteriophage displaying high-affinity nanobody against HER-2 expressing breast carcinoma cells. Bacteriophage λ is a temperate phage with inherent biological safety in mammalian cells. Here we report the construction of a recombinant λ phage that efficiently expresses specific nanobody towards third domain of HER-2 target on SKBR-3 and MCF-7 cell lines in vitro. We constructed recombinant λ phage particles containing a mammalian expression cassette, C-Myc tagged, encoding VHH gene of camelid anti HER-2 third domain epitope using λ ZAP-cytomegalic virus (CMV) vector. The SKBR-3, MCF-7 and human endometrial stem cells were treated by the nanobody displayed recombinant λ phage. The cell growth inhibition assay was performed by MTT Cell Viability Assay Kit. After the fourth round of biopanning there was a significant enrichment in the phage specifically binding to the antigen. The ratio of targeted phage increased approximately 1,000-fold in the fifth round. The nanobody expressed by λ ZAP-CMV-VHH phagemid cloned in λ bioparticles significantly inhibited the proliferation of HER-2 positive SKBR-3 and MCF-7 cells. Recombinant bacteriophage λ ZAP-CMV-VHH-cDNA could be used efficiently for construction of nanobodies to mortify HER-2 positive breast carcinoma cells as a nanomedical therapeutic.

Unusual clinical presentation of a giant left ventricle hydatid cyst.

A 39-year-old woman was hospitalized in our center due to chest and left shoulder pain. Having a history of tamponade and tuberculosis, she was under treatment for the previous two months. Echocardiography, chest CT and MRI documented intramyocardial and pericardial hydatid cyst which was later confirmed by further pathological studies. Later, the cyst was removed surgically.

Cardiac MRI in a patient with coincident left ventricular non-compaction and hypertrophic cardiomyopathy.

Left ventricular non-compaction cardiomyopathy is a rare congenital cardiomyopathy that affects both children and adults. Since the clinical manifestations are not sufficient to establish diagnosis, echocardiography is the diagnostic tool that makes it possible to document ventricular non-compaction and establish prognostic factors. We report a 47-year-old woman with a history of dilated cardiomyopathy with unknown etiology. Echocardiography showed mild left ventricular enlargement with severe systolic dysfunction (EF = 20-25%). According to cardiac magnetic resonance imaging findings non-compaction left ventricle with hypertrophic cardiomyopathy was considered, and right ventricular septal biopsy was recommended. Right ventricular endomyocardial biopsy showed moderate hypertrophy of cardiac myocytes with foci of myocytolysis and moderate interstitial fibrosis. No evidence of infiltrative deposition was seen.