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.

Compression stockings for treating vasovagal syncope (COMFORTS-II) trial: Rationale and design of a triple-blind, multi-center, randomized controlled trial.

BACKGROUND: Reduced venous return is an important trigger of vasovagal syncope (VVS). Elastic compression stockings (ECS) can modify venous return and be of therapeutic interest; however, evidence for ECS efficacy in VVS is scarce. This randomized controlled trial was designed to address the issue. METHODS: COMFORTS-II is a multicenter, triple-blind, parallel design, randomized controlled trial aimed to assess the efficacy of ECS in preventing VVS recurrences. Using central online randomization, 268 participants will be allocated to 2 arms (1:1 ratio), wearing intervention ECS (25-30 mm Hg pressure) or sham ECS (≤10 mm Hg pressure). All participants will receive standard VVS treatment in the form of education, and lifestyle modification recommendations (drinking 2-3 l/d of fluids and consuming 10 g/d-roughly half a tablespoon-of table salt). Adherence to ECS treatment will be evaluated through diary sheets, and compared between study arms. Follow-up continues for 1 year, and is conducted via a 24/7 phone line available to patients and trimonthly visits. The co-primary outcomes are proportion of participants with any syncopal recurrence and time to first syncopal episode. Secondary outcomes include frequency of VVS spells, time intervals between recurrences, and incidence of any patient-reported adverse effects. CONCLUSION: To the best of our knowledge, COMFORTS-II is the first clinical trial to assess ECS efficacy among patients with VVS, addressing an important gap in evidence for VVS treatments.

Transcranial direct current stimulation in patient with J wave syndrome and implantable cardioverter defibrillator.

J wave syndrome is a spectrum of proarrhythmic disorders including Brugada syndrome and early repolarization syndrome (ERS), that are prone to ventricular fibrillation and sudden cardiac death (SCD). In this case report we present a patient with ERS and aborted SCD complicated with cognitive impairment. We also investigated whether performing transcranial direct current stimulation to target his cognitive impairment, interfered with the function of his implantable cardioverter defibrillator.

Comparison of Outcomes with Midodrine and Fludrocortisone for Objective Recurrence in Treating Syncope (COMFORTS trial): Rationale and design for a multi-center randomized controlled trial.

BACKGROUND: The cornerstone of the treatment of vasovagal syncope (VVS) is lifestyle modifications; however, some patients incur life-disturbing attacks despite compliance with these treatments which underscores the importance of pharmacological interventions. METHODS: In this open-label multi-center randomized controlled trial, we are going to randomize 1375 patients with VVS who had ≥2 syncopal episodes in the last year into three parallel arms with a 2:2:1 ratio to receive midodrine, fludrocortisone, or no medication. All patients will be recommended to drink 2 to 3 liters of fluids per day, consume 10 grams of NaCl per day, and practice counter-pressure maneuvers. In medication arms, patients will start on 5 mg of midodrine TDS or 0.05 mg of fludrocortisone BD. After one week the dosage will be up-titrated to midodrine 30 mg/day and fludrocortisone 0.2 mg/day. Patient tolerance will be the principal guide to dosage adjustments. We will follow-up the patients on 3, 6, 9, and 12 months after randomization. The primary outcome is the time to first syncopal episode. Secondary outcomes include the recurrence rate of VVS, time interval between first and second episodes, changes in quality of life (QoL), and major and minor adverse drug reactions. QoL will be examined by the 36-Item Short Form Survey questionnaire at enrollment and 12 months after randomization. CONCLUSION: The COMFORTS trial is the first study that aims to make a head-to-head comparison between midodrine and fludrocortisone, against a background of lifestyle modifications for preventing recurrences of VVS and improving QoL in patients with VVS.

Adverse electrocardiographic effects of rituximab infusion in pemphigus patients.

Pemphigus encompasses a group of chronic autoimmune blistering diseases of the skin and/or mucosa. Rituximab (RTX) has shown promising efficacy for the treatment of pemphigus in the past decade. Considering potential cardiac side effects, this study was conducted to assess the effects of RTX on electrocardiogram (ECG) parameters in pemphigus patients. This observational cross-sectional study was conducted in 80 consecutive patients with pemphigus who were eligible for RTX infusion. The patients' heart rhythm was monitored before, during and after RTX infusion and ECG parameters were compared before and after the infusion. Eighty patients were included in the study. The median age of the patients was 42 years. The mean and maximum heart rate (HR) increased significantly after RTX infusion compared with pre-infusion mean and maximum HR. The mean corrected QT (QTc) interval, premature atrial contraction (PAC), and premature ventricular contraction (PVC) counts increased significantly after RTX infusion (P value: 0.009, 0.004 and 0.007 respectively). According to the results of this study, RTX has potential arrhythmogenic side effects including increased mean and maximum HR, QTc interval, PAC and PVC count. However, these findings are minor and should not prevent eligible patients from receiving RTX infusion.

Efficacy of Intravenous Acetaminophen in Periimplantation Pain of Cardiac Electronic Devices: A Randomized Double-Blinded Study.

PURPOSE: Although intravenous acetaminophen has been administered to reduce postoperative pain, it has not been used during cardiac implantable electronic devices (CIEDs) implantation. DESIGN: This was a randomized double-blinded interventional study. METHODS: Thirty-two patients who were referred for new CIED implantation during July 2012 until April 2013 randomly received placebo or 1 g of intravenous acetaminophen. All patients were treated with local anesthesia. Pain score during incision, pocket creation, and in the recovery room, and the patients' need for analgesics during the 6 hours after the procedure were recorded in both groups. FINDINGS: Seventeen and 15 patients received acetaminophen and placebo, respectively. Pain scores in patients treated with acetaminophen were significantly lower (4.4 vs 2.9, P = .004), and they received less analgesics (17% vs 60%, P = .014). CONCLUSIONS: Intravenous administration of acetaminophen is effective for pain relief in patients undergoing CIED implantation and decreases the need for postoperative analgesics.

Prediction of midterm performance of active-fixation leads using current of injury.

BACKGROUND: There are only limited prospective data on the clinical relevance of current of injury (COI) as a predictor of the midterm performance of active-fixation leads. This study sought to investigate whether it is possible to predict the midterm performance of active-fixation leads using COI recorded at the time of implantation. METHODS AND RESULTS: One hundred fifty patients (78 men; mean age, 63 ± 19 years) who received active-fixation pacing (n = 201) and defibrillator (n = 51) leads were studied. COI was measured from the intracardiac bipolar electrogram recorded at the time of lead implantation. The study outcome was good lead performance at 6 months, defined as P wave ≥ 1.5 mV, threshold <1.5 V for atrial lead, R-wave ≥ 5 mV, and threshold <1 V for ventricular lead. A total of 102 active-fixation atrial and 150 ventricular leads were implanted. During a 6-month follow-up, invasive intervention was required for seven atrial and seven ventricular leads. In multivariate analysis, COI was the only independent predictor of good outcome for the active-fixation atrial (odds ratio [OR]: 5.67, 95% confidence interval [CI]: 2.18-14.76, P = 0.001) and ventricular leads (OR: 3.99, 95% CI: 1.08-21.26, P = 0.002). Receiver-operating characteristic analysis identified ST-segment elevation ≥2.0 mV for the atrial leads (sensitivity, 75%; specificity, 89%) and ≥10.0 mV for the ventricular leads (sensitivity, 70%; specificity, 87%) as optimal cutoffs for good midterm performance. CONCLUSIONS: Midterm performance of active-fixation leads is predictable using COI recorded at the time of lead implantation. A ST-segment elevation ≥2.0 mV in the atrial leads and ≥10.0 mV in the ventricular leads are recommended to improve the lead performance at 6 months.

Late recognition of cardiac implantable electronic device misplacement in left ventricle: a case report.

Background: Cardiac electronic device implantation may be associated with complications. Case Summary: This is a report of inadvertent implantation of implantable cardioverter-defibrillator lead through an unrecognized sinus venosus atrial septal defect into the left ventricle that was not diagnosed early after implantation. Six months later chest x-ray showed an abnormal lead course that was confirmed with echocardiography as to be in the left ventricle. Surgical removal of the implantable cardioverter-defibrillator lead, repair of atrial septal defect, and correction of abnormal pulmonary venous connections were performed. Meanwhile, follow-up of the patient receiving a new dual chamber permanent pacemaker from the contralateral side and discussion of the aforementioned complication are addressed. Conclusion: Early diagnosis of device implantation complication is of paramount importance and prevents potential catastrophic complications.

This is a report of a middle-aged woman who received a heart battery (pacemaker) without proper initial indication and faced unnecessary consequences/complications. The wire was supposed to be implanted in the right side of the heart, but due to the congenital heart disease of the patient (that was not diagnosed), the wire was erroneously passed through the congenital defect to the left side of the heart. After the diagnosis of the problem, we referred her to a heart surgeon to correct the congenital heart defect and also pull the wire out. After open surgery, a new pacemaker (with two wires) was implanted in the patient without any additional complications.

Esophageal injury, perforation, and fistula formation following atrial fibrillation ablation.

BACKGROUND: Esophageal perforation and fistula formation are rare but serious complications following atrial fibrillation ablation. In this review article, we outline the incidence, pathophysiology, predictors, and preventative strategies of this dreaded complication. METHODS: We conducted an electronic search in 10 databases/electronic search engines to access relevant publications. All articles reporting complications following atrial fibrillation ablation, including esophageal injury and fistula formation, were included for systematic review. RESULTS: A total of 130 manuscripts were identified for the final review process. The overall incidence of esophageal injury following atrial fibrillation ablation was significantly higher with thermal ablation modalities (radiofrequency 5-40%, cryoballoon 3-25%, high-intensity focused ultrasound < 10%) as opposed to non-thermal ablation modalities (no cases reported to date). The incidence of esophageal perforation and fistula formation with the use of thermal ablation modalities is estimated to occur in less than 0.25% of all atrial fibrillation ablation procedures. The use of luminal esophageal temperature monitoring probe and mechanical esophageal deviation showed protective effect toward reducing the incidence of this complication. The prognosis is very poor for patients who develop atrioesophageal fistula, and the condition is rapidly fatal without surgical intervention. CONCLUSIONS: Esophageal perforation and fistula formation following atrial fibrillation ablation are rare complications with poor prognosis. Various strategies have been proposed to protect the esophagus and reduce the incidence of this fearful complication. Pulsed field ablation is a promising new ablation technology that may be the future answer toward reducing the incidence of esophageal complications.

Importance of Zinc Homeostasis for Normal Cardiac Rhythm.

Current arrhythmia therapies such as ion channel blockers, catheter ablation, or implantable cardioverter defibrillators have limitations and side effects, and given the proarrhythmic risk associated with conventional, ion channel-targeted anti-arrhythmic drug therapies, a new approach to arrhythmias may be warranted. Measuring and adjusting the level of particular ions that impact heart rhythm can be a simple and low-complication strategy for preventing or treating specific arrhythmias. In addition, new medicines targeting these ions may effectively treat arrhythmias. Numerous studies have shown that intracellular and extracellular zinc concentrations impact the heart's electrical activity. Zinc has been observed to affect cardiac rhythm through a range of mechanisms. These mechanisms encompass the modulation of sodium, calcium, and potassium ion channels, as well as the influence on beta-adrenergic receptors and the enzyme adenylate cyclase. Moreover, zinc can either counteract or induce oxidative stress, hinder calmodulin or the enzyme Ca (2+)/calmodulin-dependent protein kinase II (CaMKII), regulate cellular ATP levels, affect the processes of aging and autophagy, influence calcium ryanodine receptors, and control cellular inflammation. Additionally, zinc has been implicated in the modulation of circadian rhythm. Additionally, zinc has been implicated in the modulation of circadian rhythm. In all the above cases, the effect of zinc largely depends on the normal or increased cellular level of zinc, which shows the importance of maintaining the serum and intracellular levels of zinc within the normal range.

Ventricular tachycardia caused by mesothelial cyst.

A 27 year-old- lady was evaluated due to recurrent ventricular tachycardia. After performing echocardiography and cardiac MRI, she was found to have large pericardial cyst. Pathologic examination confirmed it as mesothelial pericardial cyst. Up to our knowledge it is the first presentation of simple pericardial cyst as ventricular a tachycardia.

Brucella myocarditis with unusual clinical features & abnormal cardiac MRI: A case report.

Brucellosis is a zoonotic disease that remains an important public health problem in developing countries. It can affect almost all organs, including the heart. While cardiac complications of brucellosis are not common, they usually manifest as endocarditis. Brucella myocarditis, on the other hand, is a highly rare complication of brucellosis. In this case report, we present the case of a 35-year-old woman who was admitted to the hospital with severe palpitations, fever, and fatigue. Due to the patient's long history of brucellosis and clinical symptoms, she underwent cardiac evaluation, including cardiac magnetic resonance imaging, which was a promising method to diagnose Brucella myocarditis. Hopefully our patient responded well to Rifampin and Doxycycline with gentamicin. It is important to raise awareness of this rare but potentially serious complication of brucellosis and to emphasize the value of early diagnosis and treatment.

Postural Orthostatic Tachycardia Syndrome and Orthostatic Hypotension Post COVID-19.

BACKGROUND: Novel coronavirus causes coronavirus disease -19 (COVID-19). The hallmark is acute respiratory distress syndrome, but other systems' involvement is less illustrated. Our goal was to evaluate the manifestation of COVID-19 on one of the overlaps of the cardiovascular and nervous system, namely: Postural Orthostatic Tachycardia Syndrome (POTS) and Orthostatic Hypotension (OH). METHODS: This single-center cross-sectional observational study encompassed 60 consecutive patients that were hospitalized and recovered from severe or critical COVID-19. At the time of discharge, Blood Pressure (BP) and Heart Rate (HR) in the supine and upright position (1st, 3rd, 5th and 10th minutes) were measured. Symptomatic patients were reevaluated 2 months later. RESULTS: The mean age of patients was 56.6 (± 16.2) years and 42 patients were male (70%). The most frequent cardiovascular risk factor was hypertension (35%). OH and POTS were detected in 29(48.3%) and 10(16.7%) patients, respectively, at the time of hospital discharge. The mean age of patients with OH was higher than POTS and POTS was frequent in the elderly. Two months later, among 10 patients with POTS, the sign and symptoms were resolved in 8(80%). Two (20%) patients who still had positive signs and symptoms of POTS were older than 65 years. Among 29 patients with OH, the signs and symptoms were resolved in 26 (89.7%). CONCLUSION: In our study, 65% of patients had OH or POTs on the day of hospital discharge; complete recovery is gradual and needs several additional weeks. This is one of the aspects of the entity recently named "Long COVID".

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.

Successful transvenous lead extraction of abandoned lead implanted through persistent left superior vena cava.

Persistent left superior vena cava, the most common thoracic venous anomaly, may complicate transvenous lead extraction (TLE). We report a successful case of TLE in a patient with persistent left superior vena cava, despite a long dwelling time and several pocket revisions due to pocket infection. The lead was removed via a hand-powered mechanical extraction sheath, and postoperative complications did not occur. Complicated TLE cases may have a better outcome if performed in a high-volume center with experienced specialists.

Ventricular repolarization heterogeneity in patients with COVID-19: Original data, systematic review, and meta-analysis.

BACKGROUND: Coronavirus disease-2019 (COVID-19) has been associated with an increased risk of acute cardiac events. However, the effect of COVID-19 on repolarization heterogeneity is not yet established. In this study, we evaluated electrocardiogram (ECG) markers of repolarization heterogeneity in patients hospitalized with COVID-19. In addition, we performed a systematic review and meta-analysis of the published studies. METHODS: QT dispersion (QTd), the interval between T wave peak to T wave end (TpTe), TpTe/QT (with and without correction), QRS width, and the index of cardio-electrophysiological balance (iCEB) were calculated in 101 hospitalized COVID-19 patients and it was compared with 101 non-COVID-19 matched controls. A systematic review was performed in four databases and meta-analysis was conducted using Stata software. RESULTS: Tp-Te, TpTe/QT, QRS width, and iCEB were significantly increased in COVID-19 patients compared with controls (TpTe = 82.89 vs. 75.33 ms (ms), p-value = .005; TpTe/QT = 0.217 vs. 0.203 ms, p-value = .026). After a meta-analysis of 679 COVID-19 cases and 526 controls from 9 studies, TpTe interval, TpTe/QT, and TpTe/QTc ratios were significantly increased in COVID-19 patients. Meta-regression analysis moderated by age, gender, diabetes mellitus, hypertension, and smoking reduced the heterogeneity. QTd showed no significant correlation with COVID-19. CONCLUSION: COVID-19 adversely influences the ECG markers of transmural heterogeneity of repolarization. Studies evaluating the predictive value of these ECG markers are warranted to determine their clinical utility.