HIV-1 Infection Results in Sphingosine-1-Phosphate Receptor 1 Dysregulation in the Human Thymus.

Regeneration of functional naïve T lymphocytes following the onset of human immunodeficiency virus (HIV) infection remains a crucial issue for people living with HIV (PLWH), even when adhering to antiretroviral therapy (ART). Thus far, reports on the impact of HIV-1 infection on the entry of thymic precursors and the egress of functional naïve T lymphocytes to and from the thymus are limited. We examined the impact of HIV-1 on Sphingosine-1-phosphate (S1P) signaling, which governs the egress of functional naïve thymocytes from the thymus to the periphery. Using in vitro experiments with primary human thymocytes and in vivo and ex vivo studies with humanized mice, we show that HIV-1 infection results in upregulation of the expression of S1P receptor 1 (S1PR1) in the human thymus. Intriguingly, this upregulation occurs during intrathymic infection (direct infection of the human thymic implant) as well as systemic infection in humanized mice. Moreover, considering the dysregulation of pro- and anti-inflammatory cytokines in infected thymi, the increased expression of S1PR1 in response to in vitro exposure to Interferon-Beta (IFN-ß) and Tumor Necrosis Factor-Alpha (TNF-α) indicates that cytokine dysregulation following HIV infection may contribute to upregulation of S1PR1. Finally, an increased presence of CD3hiCD69- (fully mature) as well as CD3hiCD69+ (less mature) T cells in the spleen during HIV infection in humanized mice, combined with earlier expression of S1PR1 during thymocyte development, suggests that upregulation of S1PR1 may translate to increased or accelerated egress from the thymus. The egress of thymocytes that are not functionally mature from the thymus to peripheral blood and lymphoid organs may have implications for the immune function of PLWH.

A case report of percutaneous MitraClip implantation in an adult with a double-outlet right ventricle.

Background: Atrioventricular valve regurgitation (AVVR) is present in up to 75% of Fontan patients, and it is associated with an increased risk of Fontan circulation failure, morbidity, and mortality. Traditional treatment options include surgical repair vs. surgical replacement. We present, to the best of our knowledge, one of the first cases of successful trans-catheter repair of severe common AVVR using the MitraClip device. Case summary: A 20-year-old male with a history of double-outlet right ventricle (DORV) with unbalanced common atrioventricular canal to the right ventricle, severely hypoplastic left ventricle, and total anomalous pulmonary venous return status post-Fontan procedure presented with progressively worsening dyspnoea on exertion. Transoesophageal echocardiogram demonstrated severe common AVVR. After discussion of the case during the adult congenital heart disease multidisciplinary conference, patient underwent successful placement of two MitraClip devices, reducing the regurgitation from torrential to moderate. Discussion: MitraClip therapy can be used to alleviate symptoms in patients deemed as high risk for surgery. However, careful attention must be paid to haemodynamics before and after clip placement, which may predict short-term clinical outcomes.

Characterization of T Follicular Helper Cells and T Follicular Regulatory Cells in HIV-Infected and Sero-Negative Individuals.

Humoral immune response is important in fighting pathogens by the production of specific antibodies by B cells. In germinal centers, T follicular helper (TFH) cells provide important help to B-cell antibody production but also contribute to HIV persistence. T follicular regulatory (TFR) cells, which inhibit the function of TFH cells, express similar surface markers. Since FOXP3 is the only marker that distinguishes TFR from TFH cells it is unknown whether the increase in TFH cells observed in HIV infection and HIV persistence may be partly due to an increase in TFR cells. Using multicolor flow cytometry to detect TFH and TFR cells in cryopreserved peripheral blood mononuclear cells from HIV-infected and non-infected participants in the UCLA Multicenter AIDS Cohort Study (MACS), we identified CD3+CXCR5+CD4+CD8-BCL6+ peripheral blood TFH (pTFH) cells and CD3+CXCR5+CD4+CD8-FOXP3+ peripheral blood TFR (pTFR) cells. Unlike TFR cells in germinal centers, pTFR cells do not express B cell lymphoma 6 (BCL6), a TFH cell master transcriptional regulator. Our major findings are that the frequency of pTFH cells, but not pTFR cells was higher in HIV-infected participants of the MACS and that pTFH cells expressed less CCR5 in HIV-infected MACS participants. Constitutive expression of CCR5 in TFR cells supports their potential to contribute to HIV persistence.

Pediatric Surgical Pulmonary Valve Replacement Outcomes After Implementation of a Clinical Pathway.

BACKGROUND: Standardization of perioperative care can reduce resource utilization while improving patient outcomes. We sought to describe our outcomes after the implementation of a perioperative clinical pathway for pediatric patients undergoing elective surgical pulmonary valve replacement and compare these results to previously published national benchmarks. METHODS: A retrospective single-center descriptive study was conducted of all pediatric patients who underwent surgical pulmonary valve replacement from 2017 through 2020, after the implementation of a clinical pathway. Outcomes included hospital length of stay and 30-day reintervention, readmission, and mortality. RESULTS: Thirty-three patients (55% female, median age 11 [7, 13] years, 32 [23, 44] kg) were included in the study. Most common diagnosis and indication for surgery was Tetralogy of Fallot (61%) with pulmonary valve insufficiency (88%). All patients had prior cardiac surgery. Median hospital length of stay was 2 [2, 2] days, and longest length of stay was three days. There were no 30-day readmissions, reinterventions, or mortalities. Median follow-up time was 19 [9, 31] months. CONCLUSIONS: Formalization of a perioperative surgical pulmonary valve replacement clinical pathway can safely promote short hospital length of stay without any short-term readmissions or reinterventions, especially when compared with previously published benchmarks. Such formalization enables the dissemination of best practices to other institutions to reduce hospital length of stay and limit costs.

Transcatheter Systemic AV Valve-in-Valve Implantation in a Patient With LTGA and Ebstein Anomaly.

We present the first in-human transcatheter systemic atrioventricular valve-in-valve implantation in a 37-year-old patient with Ebstein anomaly, levo-transposition of the great arteries, and prior systemic valve replacement. She had severe bioprosthetic valve regurgitation and reduced systolic function. She had high surgical risk and was planned for transcatheter intervention. (Level of Difficulty: Advanced.).

Uhl's Anomaly With Left Ventricular Noncompaction: Role of Multimodality Imaging in a Rare Association.

Uhl's anomaly is a rare congenital heart disease characterized by partial or complete absence of the right ventricle myocardium. We report the first case, in a 21-year-old man, of Uhl's anomaly-associated left ventricular noncompaction. This association represents a unique clinical entity and has important implications for management strategies. (Level of Difficulty: Intermediate.).

Acute and medium term results of balloon expandable stent placement in the transverse arch-a multicenter pediatric interventional cardiology early career society study.

OBJECTIVES AND BACKGROUND: Coarctation of the aorta represents 5-8% of all congenital heart disease. Although balloon expandable stents provide an established treatment option for native or recurrent coarctation, outcomes from transverse arch (TAO) stenting, including resolution of hypertension have not been well studied. This study aims to evaluate immediate and midterm results of TAO stenting in a multi-center retrospective cohort. METHODS: TAO stenting was defined as stent placement traversing any head and neck vessel, with the primary intention of treating narrowing in the transverse aorta. Procedural details, complications and medications were assessed immediately post procedure, at 6 month follow-up and at most recent follow-up. RESULTS: Fifty-seven subjects, 12 (21%) native, and 45 (79%) surgically repaired aortic arches, from seven centers were included. Median age was 14 years (4 days-42 years), median weight 54 kg (1.1-141 kg). After intervention, the median directly measured arch gradient decreased from 20 mmHg (0-57 mmHg) to 0 mmHg (0-23 mmHg) (p < .001). The narrowest arch diameter increased from 9 mm (1.4-16 mm) to 14 mm (2.9-25 mm) (p < .001), with a median increase of 4.9 mm (1.1-10.1 mm). One or more arch branches were covered by the stent in 55 patients (96%). There were no serious adverse events. Two patients warranted stent repositioning following migration during deployment. There were no late complications. There were 8 reinterventions, 7 planned, and 1 unplanned (6 catheterizations, 2 surgeries). Antihypertensive management was continued in 19 (40%) at a median follow-up of 3.2 years (0.4-7.3 years). CONCLUSIONS: TAO stenting can be useful in selected patients for resolution of stenosis with minimal complications. This subset of patients are likely to continue on antihypertensive medications despite resolution of stenosis.

Relationship Between Evaluations of Tracheal Tube Position Using Ultrasound and Fluoroscopy in an Infant and Pediatric Population.

INTRODUCTION: A non-radiographic technique to measure the location of the tracheal tube (TT) in children is of value given the risk of inappropriate TT placement along with concerns about radiation exposure. Airway point-of-care ultrasound (POCUS) has demonstrated utility in children, but the examinations vary by age and may require non-traditional techniques or utilize less common probes. This study evaluated the performance of measuring the tracheal location of the cuffed TT using a novel, linear probe-based POCUS examination over a wide age range of children. After adjusting for the subjects' height and TT size, ultrasound measurements of the TT cuff location were compared with fluoroscopy measurements of the TT tip location. METHODS: Perioperative pediatric patients (<10 years) requiring a cuffed TT were enrolled. After routine TT placement, ultrasound and fluoroscopy images were obtained. Measurements from the TT cuff to the cricoid cartilage were obtained from the POCUS examination. Chest fluoroscopy was reviewed to measure the TT's distance from the carina. Both measurements were then compared after scaling for patient height. The duration of the ultrasound examination and image quality scores were also recorded. RESULTS: Forty-one patients were enrolled, with a median age of 3 (25th/75th percentile: 1.50/7.00) years. The POCUS examination identified the TT cuff in all cases with the highest image quality score. The median POCUS exam time was 112 (25th/75th percentile: 80.00/156.00) seconds. There was a strong correlation between the POCUS measurements and the fluoroscopy measurements, r = -0.7575, 95% CI [-0.8638, -0.5866 ], p < 0.001). CONCLUSIONS: Our results demonstrate a strong correlation between POCUS TT localization measurements and traditional measurements via fluoroscopy. This study further supports the utility of POCUS for pediatric care.

Novel Multidisciplinary Management of Acute Kidney Injury After Infant Orthotopic Heart Transplantation.

Acute kidney injury following orthotopic heart transplantation in pediatric recipients is often multifactorial, requiring balance of immune suppression, nephrotoxic medication exposure, nutrition, and fluid status. Therapeutic options are often limited by patient size and hemodynamic stability. We describe a four-month, 4.9-kg female bridged by mechanical circulatory support to transplant after failed stage 1 palliation secondary to recurrent aortic stenosis and severe ventricular dysfunction. Posttransplant, kidney injury was managed by transcatheter relief of central obstruction from an anastomotic stricture and continuous renal replacement therapy, allowing uninterrupted immune suppression, medication, and nutrition delivery until sufficient recovery of renal function.

Resource Allocation and Decision Making for Pediatric and Congenital Cardiac Catheterization During the Novel Coronavirus SARS-CoV-2 (COVID-19) Pandemic: A U.S. Multi-Institutional Perspective.

BACKGROUND: The novel coronavirus (COVID-19) pandemic has placed severe stress on healthcare systems around the world. There is limited information on current practices in pediatric cardiac catheterization laboratories in the United States (US). OBJECTIVES: To describe current practice patterns and make recommendations regarding potential resource allocation for congenital cardiac catheterization during the COVID-19 pandemic. METHODS: A web-based survey was distributed regarding case candidacy and catheterization laboratory preparedness. Centers were categorized based on the current degree of disease burden in that community (as of April 1, 2020). Data and consensus opinion were utilized to develop recommendations. RESULTS: Respondents belonged to 56 unique US centers, with 27 (48.2%) located in counties with a high number of COVID-19 cases. All centers have canceled elective procedures. There was relative uniformity (>88% agreement) among centers as to which procedures were considered elective. To date, only three centers have performed a catheterization on a confirmed COVID-19 positive patient. Centers located in areas with a higher number of COVID-9 cases have been more involved in a simulation of donning and doffing personal protective equipment (PPE) than low-prevalence centers (46.7% vs 10.3%, respectively; P<.001). Currently, only a small fraction of operators has been reassigned to provide clinical services outside their scope of practice. CONCLUSIONS: At this stage in the COVID-19 pandemic, pediatric/congenital catheterization laboratories have dramatically reduced case volumes. This document serves to define current patterns and provides guidance and recommendations on the preservation and repurposing of resources to help pediatric cardiac programs develop strategies for patient care during this unprecedented crisis.

Here today, gone tomorrow: Outcomes of residual leak following secundum atrial septal defect closure with the GORE CARDIOFORM Septal Occluder.

OBJECTIVE: To assess the outcomes and potential predictors of residual leak after implantation of the GORE CARDIOFORM Septal Occluder (GSO) in secundum atrial septal defects (ASDs). BACKGROUND: The non-self-centering design of the GSO could lead to residual leak at the edge of the device. Outcomes of residual leak are poorly understood. METHODS: Retrospective, multicenter review of patients treated with the GSO for the pivotal and continued access study. Procedural, echocardiographic, and follow up data were reviewed. Multivariate analysis was performed to determine predictors of leak at implant and outcomes of these leaks. RESULTS: There were 370 total ASD device closures with the GSO, 65 (17.56%) of which were found to have residual leak at implantation. Patients with residual leak had larger defects (10.33 ± 3.05 mm vs. 9.13 ± 2.89 mm, p = .006) and smaller aortic rims (4.87 ± 3.33 mm vs. 6.17 ± 3.78 mm, p = .019), as compared to those without leak. Larger devices were implanted (p = .008) and more devices per case (p = .007) were utilized in the residual leak cohort as compared to those without leak. Overall, among patients with residual leak, there was a significant decrease in leak size over 1 year, from 1.55 ± 0.75 mm to 0.25 ± 0.74 mm (p < .001), with the majority (87.6%) disappearing by 12-month follow-up. CONCLUSIONS: Residual leak at implantation can be seen after ASD device closure with the GSO, more commonly in larger defects with smaller retroaortic rims. The vast majority of these leaks completely resolve by 1 year follow up.

Elective left pulmonary artery embolisation for pulmonary arteriovenous malformations secondary to cavopulmonary anastomoses not responsive to heart transplantation: a case report.

A 10-year-old female with heterotaxy-asplenia and complex CHD developed pulmonary arteriovenous malformations with associated cyanosis after Fontan completion. She underwent orthotopic heart transplantation, but her pulmonary arteriovenous malformations persisted with progressive worsening cyanosis. Elective transcatheter left pulmonary artery embolisation was performed 2 years post-transplant, which successfully normalised her oxygen saturation without a significant increase in pulmonary artery pressure.

Variation in Anticoagulation Practices in the Congenital Cardiac Catheterization Lab: Results of a Multinational PICES Survey.

The complex nature of congenital heart disease (CHD) has hindered the establishment of management standards for peri-catheterization anticoagulation. We sought to describe anticoagulation practice variability among providers performing cardiac catheterization in children and adults with CHD. A web-based survey ( http://www.surveymonkey.com ) was distributed to pediatric and congenital interventional cardiologists. Respondents were queried on their training, practice setting, years in practice, and case volume. Clinical questions focused on general anticoagulation strategies and on five common clinical scenarios: two diagnostic (biventricular circulation, single ventricle physiology) and three interventional cardiac catheterizations (atrial septal defect closure, pulmonary artery stenting in Fontan circulation, stent placement for coarctation of aorta). Seventy-seven pediatric and congenital interventional cardiologists responded to the survey (81% in the United States). Twenty-six (36%) worked in a public medical institution; 57% worked in a free-standing children's hospital. Twenty-six percent had been in practice for < 5 years and 32% for > 15 years; 75% completed additional training in interventional congenital cardiology. The median number of cases performed was 200/year (IQR 110); median number of interventional cases was 100/year (IQR 100). Responses to general queries and specific clinical scenarios suggested significant variation in anticoagulation practices, including monitoring of anticoagulation during catheterization, protamine use, and outpatient anticoagulation after catheterization. Practices not only varied between providers but also between different clinical scenarios. Practice patterns did not correlate with provider experience or case volume. Management of anticoagulation in the congenital cardiac catheterization lab varies from operator to operator. Our study may provide some initial insight and context for discussion regarding anticoagulation in a field of increasingly heterogeneous interventional techniques and patient substrates. Future studies would be helpful to better define "best practices" for peri-procedural thromboprophylaxis in patients with congenital heart disease.

Results of the combined U.S. multicenter postapproval study of the Nit-Occlud PDA device for percutaneous closure of patent ductus arteriosus.

OBJECTIVES: To report the results of the Nit-Occlud PDA prospective postapproval study (PAS) along with a comparison to the results of the pivotal and continued access trials. BACKGROUND: The Nit-Occlud PDA (PFM Medical, Cologne, Germany), a nitinol coil patent ductus arteriosus (PDA) occluder, was approved by the Food and Drug Administration in 2013. METHODS: The PAS enrolled a total of 184 subjects greater than 6 months of age, weighing at least 5 kg, with PDAs less than 4 mm by angiography at 11 centers. Patients were followed prospectively at 2 months, 12 months, and 24 months postprocedure. These outcomes were compared to the 357 subjects enrolled in the pivotal and continued access protocols. Efficacy and safety data were reported. RESULTS: Among 184 subjects enrolled for the PAS between 2014 and 2017, 180 (97.8%) had successful device implantation. After 12 months, 98.7% (150/152) had trivial or no residual shunt by echocardiography and two subjects had only small residual shunts. There were three device embolizations that were all retrieved by snare without clinical consequence. Together with the pivotal and continued access study, 97.4% (449/461) had complete echocardiographic closure at 12 months in 541 enrolled subjects. The composite success was 94.4%. There were no mortalities and no serious device-related adverse events. CONCLUSIONS: The Nit-Occlud PDA is a safe and effective device for closure of a small to moderate sized PDA. There were no serious device-related adverse events in a large cohort of three clinical trials.

Subaortic Stenosis Resection in Children: Emphasis on Recurrence and the Fate of the Aortic Valve.

BACKGROUND: Recurrence after surgical resection of discrete subvalvar aortic stenosis in children often requires repeat operation. Risk factors for recurrence are poorly understood. We sought to determine potential risk factors for recurrence and postoperative comorbidities in the long term. METHODS: Retrospective chart review was performed on all pediatric patients who underwent surgical resection of discrete subaortic stenosis at our institution. Demographics, perioperative findings, and clinical data were analyzed for predisposing factors. RESULTS: From 1991 to 2015, a total of 104 patients underwent primary surgical resection of discrete subaortic stenosis. There were no postoperative deaths. Three (2.9%) patients required pacemaker implantation. Nine (8.4%) patients required repeat resection for recurrence of subaortic membrane over a median follow-up of 8.5 years (interquartile range: 5.9-13.5 years). Actuarial freedom from repeat resection was 100%, 94%, and 82% at one, five, and ten years, respectively. Repeat resection occurred more frequently in patients with genetic disease (37.5% vs 10.7%; P = .033) and preoperative mitral regurgitation (MR; 25% vs 1.2%; P < .001). Postoperative aortic insufficiency (AI) that was moderate or worse was associated with older age at the time of first resection (relative risk [RR]: 1.54, P < .05), moderate or severe preoperative AI (RR: 1.84, P = .002), and repeat resection of subaortic stenosis (RR: 1.90, P < .001). CONCLUSION: The majority of children who undergo surgical resection of subaortic stenosis will not experience recurrence in childhood and those who do require repeat resection may have a higher incidence of genetic disease and preoperative MR. Postoperative AI is associated with repeat resection, older age at the time of surgery, and degree of preoperative AI.

A practical guide to cardiovascular 3D printing in clinical practice: Overview and examples.

The advent of more advanced 3D image processing, reconstruction, and a variety of three-dimensional (3D) printing technologies using different materials has made rapid and fairly affordable anatomically accurate models much more achievable. These models show great promise in facilitating procedural and surgical planning for complex congenital and structural heart disease. Refinements in 3D printing technology lend itself to advanced applications in the fields of bio-printing, hemodynamic modeling, and implantable devices. As a novel technology with a large variability in software, processing tools and printing techniques, there is not a standardized method by which a clinician can go from an imaging data-set to a complete model. Furthermore, anatomy of interest and how the model is used can determine the most appropriate technology. In this over-view we discuss, from the standpoint of a clinical professional, image acquisition, processing, and segmentation by which a printable file is created. We then review the various printing technologies, advantages and disadvantages when printing the completed model file, and describe clinical scenarios where 3D printing can be utilized to address therapeutic challenges.

Serial Versus Direct Dilation of Small Diameter Stents Results in a More Predictable and Complete Intentional Transcatheter Stent Fracture: A PICES Bench Testing Study.

Balloon-expandable stents, implanted in infants and children with congenital heart disease (CHD), often require redilation to match somatic growth. Small diameter stents may eventually require longitudinal surgical transection to prevent iatrogenic vascular stenosis. Intentional transcatheter stent fracture (TSF) is an emerging alternative approach to stent transection, but little is known about the optimal stent substrate and best protocol to improve the likelihood of successful TSF. Bench testing was performed with a stent dilation protocol. After recording baseline characteristics, stents were serially or directly dilated using ultra-high-pressure balloons (UHPB) until fracture occurred or further stent dilation was not possible. Stent characteristics recorded were as follows: cell design, metallurgy, mechanism, and uniformity of fracture. Stents tested included bare-metal coronary stents, premounted small diameter stents, and ePTFE-covered small diameter premounted stents. Ninety-four stents representing 9 distinct models were maximally dilated, with 80 (85%) demonstrating evidence of fracture. Comprehensive fracture details were recorded in 64 stents: linear and complete in 34/64 stents (53.1%), linear and incomplete in 9/64 stents (14.1%), transverse/complex and complete in 6/64 stents (9.4%), and transverse/complex and incomplete in 15/64 stents (23.4%). Stent fracture was not accomplished in some stent models secondary to significant shortening, i.e., "napkin-ring" formation. Serial dilation resulted in evidence of fracture in 62/67 (92.5%) stents compared with 18/27 (66.7%) stents in the direct dilation group (p = 0.003). Intentional TSF is feasible in an ex vivo model. Serial dilation more reliably expanded the stent and allowed for ultimate stent fracture, whereas direct large diameter dilation of stents was more likely to generate a "napkin-ring" configuration, which may be more resistant to fracture. In vivo animal and human testing is necessary to better understand the response to attempted TSF for newly developed stents as well as those currently in use.

Acute and midterm results following perventricular device closure of muscular ventricular septal defects: A multicenter PICES investigation.

OBJECTIVES: To describe acute and mid-term results of hybrid perventricular device closure of muscular ventricular septal defects (mVSDs). BACKGROUND: Perventricular device closure of mVSDs can mitigate technical limitations of percutaneous closure and need for cardiopulmonary bypass or ventriculotomy with a surgical approach. METHODS: This is a multicenter retrospective cohort study of patients undergoing hybrid perventricular mVSD device closure from 1/2004 to 1/2014. Procedural details, adverse events, outcomes, and follow-up data were collected. Patients were divided into two groups: (1) simple (mVSD closure alone) and (2) complex (mVSD closure with concomitant cardiac surgery). RESULTS: Forty-seven patients (60% female) underwent perventricular mVSD device closure at a median age of 5.2 months (IQR 1.8-8.9) and weight of 5.1 kg (IQR 4.0-6.9). Procedural success was 91% [100% (n = 22) simple and 84% (n = 21/25) complex]. Adverse events occurred in 19% (9/47) [9% (2/22) simple and 28% (7/25) complex]. Hospital length of stay (LOS) was shorter in the simple vs. complex group (4 vs. 14 days, P < 0.01). At mid-term follow-up of 19.2 months (IQR 2.3-43) 90% of pts had complete mVSD closure; none developed late heart block, increased atrioventricular (AV) valve insufficiency or ventricular dysfunction. CONCLUSIONS: Perventricular device closure of simple mVSD was associated with a high rate of procedural success, few adverse events, and short hospital LOS. Procedural adverse events were associated with the presence of concomitant complex surgery. Residual mVSD, AV valve insufficiency, or ventricular dysfunction were uncommon at mid-term follow-up. © 2017 Wiley Periodicals, Inc.

Pharmacologic Treatment of Cannabinoid Hyperemesis Syndrome: A Systematic Review.

Cannabinoid hyperemesis syndrome (CHS) has become more prevalent with increasing cannabis use. CHS is often resistant to standard antiemetics. The objective of this study is to review the current evidence for pharmacologic treatment of CHS. Medline, PsycINFO, DARE, OpenGrey, Google Scholar, and the Cochrane Library were searched from inception to February 2017. Articles were selected and reviewed independently. Evidence was graded using Oxford Center for Evidence-Based Medicine guidelines. The search resulted in 1262 articles with 63 of them eligible for inclusion (205 human subjects). There were 4 prospective level-2, 3 retrospective level-3 studies, 12 level-4 case series, and 44 level-5 case reports. Among level-2 studies (64 subjects), tricyclic antidepressants (TCAs) and lorazepam were discussed as effective long- and short-term treatments, respectively, in two studies. Ondansetron, promethazine, diphenhydramine, and opioids were also mentioned, but the authors did not comment on their efficacy. Among level-3 studies (43 subjects), one reported effective treatment with antiepileptics zonisamide and levetiracetam, but not TCAs. Another reported favorable response to morphine, ondansetron, and lorazepam but did not specify the actual number of patients receiving specific treatment. Among the level-4 case series (54 subjects), benzodiazepines, haloperidol, and capsaicin were reported as helpful. For level-5 case reports (44 subjects), benzodiazepines, metoclopramide, haloperidol, ondansetron, morphine, and capsaicin were reported as effective. Effective treatments mentioned only once included fentanyl, diazepam, promethazine, methadone, nabilone, levomepromazine, piritramide, and pantoprazole. Hot showers and baths were cited in all level-4 and -5 articles as universally effective. High-quality evidence for pharmacologic treatment of CHS is limited. Benzodiazepines, followed by haloperidol and capsaicin, were most frequently reported as effective for acute treatment, and TCAs for long-term treatment. As the prevalence of CHS increases, future prospective trials are greatly needed to evaluate and further define optimal pharmacologic treatment of patients with CHS.