Reproducible asystole following vagal nerve stimulator lead replacement: a case report.

BACKGROUND: Vagal nerve stimulation (VNS) is approved therapy for the treatment of intractable epilepsy. The stimulation of either nerve, left or right, is effective. However, due to the anatomic and physiological effects of cardiac innervation, the right vagus nerve is typically avoided in order to minimize the risk of cardiac bradyarrhythmias. The location of the VNS lead contacts on the nerve can also have an effect, namely, more distally placed contacts have been associated with lower risk of cardiac arrhythmias, presumably by avoiding vagal cervical cardiac branches; however, our case demonstrates reproducible asystole despite left sided, distal VNS lead placement. CASE PRESENTATION: We report a 28-year-old male patient with pharmacoresistant generalized clonic-tonic seizures. The VNS therapy with 1.5 mA output and 16% duty cycle drastically reduced his seizure burden for several years. The breakthrough seizures along with stabbing pain episodes at the implantable pulse generator (IPG) site have prompted the VNS lead revision surgery with new lead contacts placed more caudally than the old contacts. However, the intraoperative device interrogation with 1 mA output resulted in immediate asystole for the duration of stimulation and it was reproducible until the output was decreased to 0.675 mA. CONCLUSIONS: Our case highlights the possibility of new severe cardiac bradyarrhythmias following surgical VNS lead replacements even in patients without preoperatively known clinical side effects. We suggest preoperative electrocardiography and cardiology consultation for detected abnormalities for all patients undergoing new VNS implantations, as well as revision surgeries for VNS malfunctions. Intraoperatively, the surgeon and anesthesia team should be vigilant of cardiac rhythms and prepared for the immediate management.

Direct Oral Anticoagulants Versus Warfarin in Left Ventricular Thrombus: A Systematic Review and Meta-Analysis.

BACKGROUND: There are conflicting results regarding the safety and efficacy of direct oral anticoagulants (DOACs) in the management of left ventricular thrombus (LVT) compared with the vitamin K antagonist warfarin. STUDY QUESTION: What is the safety and efficacy of DOACs in the management of LVT compared with warfarin? DATA SOURCE: Randomized clinical trials and cohort studies in the MEDLINE and Cochrane databases from inception till April 4, 2021. STUDY DESIGN: The present analysis is a systematic review and meta-analysis. Desired outcomes were all-cause mortality, complete resolution of LVT, stroke and systemic emboli, and major bleeding. The risk ratio (RR) of the outcomes and 95% confidence intervals (CIs) were calculated using a random-effects modeling approach. RESULTS: Twelve studies with a total of 2322 patients were included. There was no difference between the 2 interventions in the resolution of LVT [RR 0.97 (CI 0.93-1.02)], stroke and systemic embolism [RR 0.95 (CI 0.63-1.45)], bleeding [RR 1.14 (CI 0.81-1.60)], and all-cause mortality [RR 0.99 (CI 0.67, 1.46)]. CONCLUSIONS: DOACs and warfarin have comparable safety and efficacy outcomes in the management of LVT.

The sensitivity of graphic trends in differentiating sinus and supraventricular tachycardia.

BACKGROUND: The use of cardiac telemetry in the inpatient setting is widespread and has become integral in managing hospitalized patients. Telemetry is used to monitor patients with brady- and tachyarrhythmias. While most of the focus is on the rhythm strip data, a significant utility remains in analyzing the graphic heart rate trends. We specifically focused on the shape of the curve (rectangle or bell) of the heart rate over time to differentiate sinus tachycardia (ST) and supraventricular tachycardia (SVT). We hypothesized that identifying the shape of the graphic trend would improve the accuracy of diagnosis. METHODS: To demonstrate the simplicity of employing this method for improving the diagnosis of arrhythmia, we had senior medical students evaluate the telemetry strips and graphical trends. We gathered data from the medical student interpretation of 82 strips of in-hospital cardiac telemetry and asked them to differentiate ST and SVT based on the shape of the graphic trend. Each rhythm strip and the graphic trend was interpreted by two clinical cardiac electrophysiology attending physicians and confirmed on a 12­lead electrocardiogram. RESULTS: When students were asked to choose between ST and SVT based on the telemetry rhythm strip without graphic trends, 73% of their answers were correct. Diagnostic accuracy improved to 96% correct with the addition of the graphic trend. Depending on the telemetry rhythm strip alone, sensitivity to detect SVT was 75%, with 68% specificity. With the addition of the graphical trend, sensitivity improved to 98% and specificity 100%. CONCLUSION: Review of graphical trends, specifically the analysis of onset and offset, allows novice ECG readers to improve the ability to distinguish between ST and SVT.

Coronary artery injury related to catheter ablation of cardiac arrhythmias: A systematic review.

INTRODUCTION: Catheter ablation (CA) has emerged as the preferred modality of treatment for many cardiac arrhythmias. Anatomical sites of ablation are often located in close proximity to coronary arteries. However, the incidence of CA-related coronary injury has not been well studied. We sought to systematically evaluate all cases of CA-related coronary injuries. METHODS AND RESULTS: A PubMed search was conducted from inception until May 1, 2017 using the keywords "coronary artery" and "ablation." We identified 2817 published articles of which 43 articles met our inclusion criteria representing 61 cases of coronary artery injury attributed to CA procedures from 1992 to 2017. Posteroseptal accessory pathway ablation was associated with the highest incidence of coronary injury (35.6% of cases), followed by cavotricuspid isthmus-dependent flutter (19.3%). The right coronary artery was the site of injury in over two-thirds of all reported cases. Coronary injury was detected intraprocedurally in about half of the cases (43.1%), whereas it was a delayed presentation in the other half. Coronary intervention was performed in a third of all cases (32.7%). There were a total of three deaths attributed to coronary artery injury. CONCLUSIONS: Most (91.8%) coronary injuries are a result of anatomic proximity to the site of ablation. Awareness of the relation between coronary artery course and anatomical site of ablation could prevent myocardial damage and improve procedural safety.

Fish, Fish Oils and Cardioprotection: Promise or Fish Tale?

Fish and commercially available fish oil preparations are rich sources of long-chain omega-3 polyunsaturated fatty acids. Eicosapentaenoic acid (EPA) and docosahexaenoic acid (DHA) are the most important fatty acids in fish oil. Following dietary intake, these fatty acids get incorporated into the cell membrane phospholipids throughout the body, especially in the heart and brain. They play an important role in early brain development during infancy, and have also been shown to be of benefit in dementia, depression, and other neuropsychiatric disorders. Early epidemiologic studies show an inverse relationship between fish consumption and the risk of coronary heart disease. This led to the identification of the cardioprotective role of these marine-derived fatty acids. Many experimental studies and some clinical trials have documented the benefits of fish oil supplementation in decreasing the incidence and progression of atherosclerosis, myocardial infarction, heart failure, arrhythmias, and stroke. Possible mechanisms include reduction in triglycerides, alteration in membrane fluidity, modulation of cardiac ion channels, and anti-inflammatory, anti-thrombotic, and anti-arrhythmic effects. Fish oil supplements are generally safe, and the risk of toxicity with methylmercury, an environmental toxin found in fish, is minimal. Current guidelines recommend the consumption of either one to two servings of oily fish per week or daily fish oil supplements (around 1 g of omega-3 polyunsaturated fatty acids per day) in adults. However, recent large-scale studies have failed to demonstrate any benefit of fish oil supplements on cardiovascular outcomes and mortality. Here, we review the different trials that evaluated the role of fish oil in cardiovascular diseases.

Amiodarone Induced Interstitial and Organizing Pneumonia Reversed with Steroids.

Amiodarone is a widely used antiarrhythmic agent for supraventricular and ventricular tachyarrhythmias. It is known to cause pulmonary toxicity, which can manifest in a variety of presentations, ranging from asymptomatic to fatal. We present a case of chronic interstitial pneumonia with organizing pneumonia induced by amiodarone that was successfully treated with drug cessation and use of corticosteroids. The patient experienced complete resolution of symptoms and full recovery of lung function after the course of steroids.

Perioperative Heparin Bridging in Atrial Fibrillation Patients Requiring Temporary Interruption of Anticoagulation: Evidence from Meta-analysis.

BACKGROUND: Patients with atrial fibrillation (AF) often require temporary interruption of warfarin for an elective operation or invasive procedure. However, the safety and efficacy of periprocedural bridging anticoagulation with unfractionated heparin (UH) or low-molecular-weight heparin (LMWH) are still unclear. We evaluated the safety of periprocedural heparin bridging in AF patients requiring temporary interruption of oral anticoagulation. METHODS: We searched the literature for trials that compared heparin bridging with no bridging in AF patients for whom warfarin was temporarily interrupted. The incidence of all-cause mortality, thromboembolism, and major and all bleeding was included, and meta-analysis was performed. RESULTS: A total of 13,808 patients with AF were included in 4 observational studies, 1 randomized trial, and 1 subgroup analysis of a randomized trial. The mean CHADS2 score for the no heparin bridging group was 2.49 and that for the heparin bridging group was 2.34. At 30 days and up to 3 months, when compared to the heparin bridging group, the no bridging group did not have any significant difference in mortality (odds ratio [OR], 1.29; 95% confidence interval [CI], .15-11.52; P = .82) or cerebrovascular accidents (OR, .93; 95% CI, .34-2.51; P = .88), but the no bridging group had significantly less major bleeding (OR, .41; 95% CI, .24-.68; P = .0006). CONCLUSION: Among AF patients with intermediate CHADS2 scores who are anticoagulated with warfarin and who required temporary interruption of warfarin for an elective surgery or procedure, periprocedural bridging with UH or LMWH was associated with a higher rate of major bleeding with no significant difference in mortality or CVA.

Irregular Wide Complex Tachycardia in a Young Man.

Wolf Parkinson White syndrome is a pre-excitation syndrome due to an accessory conduction pathway. Electrocardiography demonstrates a short PR interval, long QRS interval and delta waves in normal sinus rhythm. Atrial fibrillation with underlying Wolf Parkinson White syndrome presents with irregular wide complex tachycardia, and can cause sudden cardiac death by precipitating ventricular fibrillation. Irregular wide complex tachycardia may be the first presentation of this underlying conduction abnormality in young patients. Emergency management for irregular wide complex tachycardia in hemodynamically unstable patients involves synchronized cardioversion, while intra-venous Procainamide can be used in hemodynamically stable patients. AV nodal blocking agents should be avoided. Treatment of choice for WPW syndrome is radiofrequency ablation.

Contemporary trends of hospitalization for atrial fibrillation in the United States, 2000 through 2010: implications for healthcare planning.

BACKGROUND: Atrial fibrillation (AF) is the most common sustained cardiac arrhythmia. The associated morbidity and mortality make AF a major public health burden. Hospitalizations account for the majority of the economic cost burden associated with AF. The main objective of this study is to examine the trends of AF-related hospitalizations in the United States and to compare patient characteristics, outcomes, and comorbid diagnoses. METHODS AND RESULTS: With the use of the Nationwide Inpatient Sample from 2000 through 2010, we identified AF-related hospitalizations using International Classification of Diseases, 9th Revision, Clinical Modification code 427.31 as the principal discharge diagnosis. Overall AF hospitalizations increased by 23% from 2000 to 2010, particularly in patients ≥65 years of age. The most frequent coexisting conditions were hypertension (60.0%), diabetes mellitus (21.5%), and chronic pulmonary disease (20.0%). Overall in-hospital mortality was 1%. The mortality rate was highest in the group of patients ≥80 years of age (1.9%) and in the group of patients with concomitant heart failure (8.2%). In-hospital mortality rate decreased significantly from 1.2% in 2000 to 0.9% in 2010 (29.2% decrease; P<0.001). Although there was no significant change in mean length of stay, mean cost of AF hospitalization increased significantly from $6410 in 2001 to $8439 in 2010 (24.0% increase; P<0.001). CONCLUSIONS: Hospitalization rates for AF have increased exponentially among US adults from 2000 to 2010. The proportion of comorbid chronic diseases has also increased significantly. The last decade has witnessed an overall decline in hospital mortality; however, the hospitalization cost has significantly increased.

Propofol-related infusion syndrome: rare and fatal.

Propofol is one of the most commonly used sedating agents in critical care units worldwide. It is generally well tolerated and preferred for its pharmacokinetic profile. Here, we describe a rare and devastating adverse effect of propofol, the propofol-related infusion syndrome.

In-hospital complications associated with catheter ablation of atrial fibrillation in the United States between 2000 and 2010: analysis of 93 801 procedures.

BACKGROUND: Atrial fibrillation ablation has made tremendous progress with respect to innovation, efficacy, and safety. However, limited data exist regarding the burden and trends in adverse outcomes arising from this procedure. The aim of our study was to examine the frequency of adverse events attributable to atrial fibrillation (AF) ablation and the influence of operator and hospital volume on outcomes. METHODS AND RESULTS: With the use of the Nationwide Inpatient Sample, we identified AF patients treated with catheter ablation. We investigated common complications including cardiac perforation and tamponade, pneumothorax, stroke, transient ischemic attack, vascular access complications (hemorrhage/hematoma, vascular complications requiring surgical repair, and accidental arterial puncture), and in-hospital death described with AF ablation, and we defined these complications by using validated International Classification of Diseases, Ninth Revision, Clinical Modification diagnosis codes. An estimated 93,801 AF ablations were performed from 2000 to 2010. The overall frequency of complications was 6.29% with combined cardiac complications (2.54%) being the most frequent. Cardiac complications were followed by vascular complications (1.53%), respiratory complications (1.3%), and neurological complications (1.02%). The in-hospital mortality was 0.46%. Annual operator (<25 procedures) and hospital volume (<50 procedures) were significantly associated with adverse outcomes. There was a small (nonsignificant) rise in overall complication rates. CONCLUSIONS: The overall complication rate was 6.29% in patients undergoing AF ablation. There was a significant association between operator and hospital volume and adverse outcomes. This suggests a need for future research into identifying the safety measures in AF ablations and instituting appropriate interventions to improve overall AF ablation outcomes.

Innovative P-wave detection for discrimination between ventricular and supraventricular tachycardia in single-chamber ICDs: is the P-wave invisible during tachycardia?

AIMS: Differentiation between supraventricular tachycardia (SVT) and ventricular tachycardia (VT) remains a substantial clinical challenge in patients with single-chamber implantable cardioverter-defibrillators (ICDs) due to absence of visible P waves. Innovative optimization of intrathoracic electrogram (EGM) configuration will facilitate P-wave detection and rhythm differentiation during tachycardia. METHODS AND RESULTS: Innovative optimization of EGM configuration was originally performed to improve patient care. In this retrospective cohort study, we examined our database for records of 140 consecutive patients undergoing single-chamber ICD implantation. During the follow-ups of 61 included patients with optimized EGM configuration, 27 patients were identified to have VT and/or SVT. EGMs in the Can (generator) to superior vena cava (Can-SVC) configuration were compared with those conventionally from the Can to right ventricular coil (Can-RV coil) source in the same patients. In Can-SVC EGMs, the ratio of P/QRS amplitude was 14-fold higher (0.57 ± 0.08 vs. 0.04 ± 0.00, P < 0.001) compared with those in Can-RV coil EGMs during sinus rhythm. With Can-SVC configuration, the odds of atrioventricular dissociation detection in patients with VT was increased 15-fold (61.9% vs. 9.5% with Can-RV coil; odds ratio, 15.4; 95% confidence interval, 2.8 to 84.7; P = 0.0009). In patients with SVT, P-waves or retrograde P-waves were markedly more identifiable in Can-SVC configuration compared with Can-RV coil (odds ratio, 40; 95% confidence interval, 3.6 to 447.1; P = 0.0010). CONCLUSION: P-wave recognition by optimizing EGM configuration provides a novel diagnostic tool for differentiation between VT and SVT in single-chamber ICDs. A potential discrimination algorithm would provide a cost-effective approach to improving the qualitative outcomes.

Amiodarone-related hyponatremia: rare but potentially lethal.

Amiodarone is a one of the most commonly used antiarrhythmic drug with efficacy in both supraventricular and ventricular tachycardia. Hepatic, pulmonary, and thyroid adverse effect profiles of this drug are well described and mandate a close follow-up. We report a case of amiodarone-related hyponatremia, which is one of the rarest side effects associated with this medication and our case was unlike other previous case reports because severity of symptoms required hemodialysis for correction of hyponatremia despite trying dose reduction strategy.

Flecainide associated torsade de pointes: A potential case of reverse use dependence.

Flecainide has been known to cause torsades de pointes (TdP) in patients with structural heart disease and its mechanism has been attributed to use-dependency. We present a patient with flecainide-induced TdP in the absence of any other precipitating factors. This case highlights potential reverse use dependence associated with flecainide resulting in TdP.

Prior Statin vs In-Hospital Statin Usage in Severe COVID-19: Review and Meta-Analysis.

Studies have shown that statins can decrease COVID-19 mortality in hospitalized patients. This paper evaluates these studies and reviews the possible mechanism of how statins modulate COVID-19 severity. Meta-analysis of 31 retrospective studies demonstrated a reduction in mortality rate among statin users (OR 0.69, 95% CI 0.56-0.86, P = 0.0008) (HR 0.83, 95% CI 0.72-0.95, P = 0.0078). Meta-analysis of 8 randomized control studies demonstrated a nonsignificant reduction in mortality (OR 0.90, 95% CI 0.69-1.18, P = 0.461), including 4 studies with medications other than statins, and 4 studies with only statins (OR 0.88, 95% CI 95% CI 0.64-1.21, P = 0.423). Prolonged statin usage decreases the extracellular localization of ACE2, along with statins' immunomodulating effects and reduction of oxidative stress, decreases COVID-19 mortality. Hospitalized patients with COVID-19 should continue statin treatment if previously prescribed, and patients should not be started on statins, as they do not seem to provide any mortality benefit.

Inappropriate Subcutaneous Implantable Cardioverter-defibrillator Shocks-A Rare Case of Triple Counting.

Sudden cardiac death (SCD) caused by ventricular tachyarrhythmias is a significant contributor to cardiovascular deaths worldwide. Implantable cardioverter-defibrillators (ICDs) have shown efficacy in preventing and reducing mortality from SCD, but traditional transvenous ICDs have inherent challenges and drawbacks, such as lead fractures, lead-associated endocarditis, and lead failure. To address these issues, subcutaneous ICDs (S-ICDs) have been developed. S-ICDs lack pacing capacity but are a valid alternative for patients at high risk for infection or with difficult venous access. Pre-implantation screening can help prevent inappropriate device shocks. We present a case in which a patient received inappropriate S-ICD therapy, which was attributed to the triple counting of P-, R-, and T-waves in a patient with sinus rhythm. This is an unusual occurrence, and, to the best of our knowledge, there are only a limited number of case reports documenting inappropriate shocks due to the oversensing of P-waves and T-waves.

A dilemma in the electrophysiology lab: where is the coronary sinus in a patient with left inferior vena cava with hemiazygos continuation?

Occasionally, electrophysiological interventions are complicated by an unusual or an anomalous cardiovascular anatomy. We report our experience of a case of situs ambiguous and symptomatic heart failure of which anomalous venous anatomy and coronary sinus variation had prevented a successful endocardial placement of a left ventricular lead for cardiac synchronization therapy.

Impact of atrial fibrillation on in-hospital outcomes among hospitalizations for cardiac surgery: an analysis of the National Inpatient Sample.

The short-term impact of atrial fibrillation (AF) on cardiac surgery hospitalizations has been previously reported in cohorts of various sizes, but results have been variable. Using the 2005-2014 National Inpatient Sample, we identified all adult hospitalizations for cardiac surgery using the International Classification of Diseases, Ninth Revision, Clinical Modification as any procedure code and AF as any diagnosis code. We estimated the impact of AF on inpatient mortality, length of stay (LOS), and cost of hospitalization using survey-weighted, multivariable logistic, accelerated failure-time log-normal, and log-transformed linear regressions, respectively. Additionally, we exact-matched AF to non-AF hospitalizations on various confounders for the same outcomes. A total of 1,269,414 hospitalizations were noted for cardiac surgery during the study period. Coexistent AF was found in 44.9% of these hospitalizations. Overall mean age was 65.6 years, 40.9% were female, mean LOS was 11.6 days, and inpatient mortality was 4.5%. Stroke rate was lower in AF hospitalizations (1.8% vs 2.1%, p<0.001). Mortality was lower in the AF (3.9%) versus the non-AF (5%) group (exact-matched OR or emOR=0.48, 95% CI 0.29 to 0.80, p<0.001; 987 matched pairs, n=2423), with similar results after procedural stratification: isolated valve replacement/repair (emOR=0.38, p<0.001), isolated coronary artery bypass graft (CABG) (emOR=0.33, p<0.001), and CABG with valve replacement/repair (emOR=0.55, p<0.001). A 12% increase was seen in LOS in the AF subgroup (exact-matched time ratio=1.12, 95% CI 1.10 to 1.14, p<0.001) among hospitalizations which underwent valve replacement/repair with or without CABG. Hospitalizations for cardiac surgery which had coexistent AF were found to have lower inpatient mortality risk and stroke prevalence but higher LOS and hospitalization costs compared with hospitalizations without AF.

Inappropriate Sinus Tachycardia Following Viral Illness.

A 67-year-old female patient with a past medical history of menopause, migraines, and gastro-esophageal disease presented with palpitation, fatigue, and shortness of breath. One month prior to her presentation, she reported having flu-like symptoms. Her EKG showed sinus tachycardia with no other abnormality. Laboratory findings, along with imaging, showed normal results. The event monitor failed to detect any arrythmias. We report a case of inappropriate sinus tachycardia secondary to viral infection as a diagnosis of exclusion.

Theophylline in Treatment of COVID-19 Induced Sinus Bradycardia.

This is a retrospective case series of two patients with laboratory-confirmed coronavirus 2 (SARS-CoV-2) infection, presented to the University of Arkansas for Medical Sciences in January 2021. Medical records of these patients were reviewed using the EPIC electronic health record system. Clinical, laboratory, and treatment data were reviewed against periods of bradycardia in each patient. Both of the patients presented with dizziness and presyncope related to sinus bradycardia in which they received treatment with 1 mg of IV atropine and theophylline 200 mg orally. We share these two cases of theophylline treatment in COVID-19 induced sinus bradycardia. The first patient was a 39-year-old female, with a past medical history of polycystic ovarian syndrome, who presented to the emergency department with lightheadedness and dizziness. Two weeks prior to her presentation, she was tested positive for COVID-19 infection that was treated with azithromycin, dexamethasone and aspirin. Upon presentation, her ECG showed sinus bradycardia at a rate of 48 bpm. The second patient, a 21-year-old female with no significant past medical history, presented with presyncope. Three weeks prior to her presentation, she tested positive for COVID-19 infection that was treated symptomatically at her home. Upon presentation, her ECG showed junctional rhythm at a heart rate of 51 bpm.