Bayesian network meta-analysis comparing cryoablation, radiofrequency ablation, and antiarrhythmic drugs as initial therapies for atrial fibrillation.

BACKGROUND: Antiarrhythmic drugs (AADs) and catheter ablation are first line treatments of paroxysmal atrial fibrillation (PAF), however, there exists a paucity of data regarding the potential benefit of different catheter ablation technologies versus AADs as an early rhythm strategy. OBJECTIVE: To assess the safety and efficacy of cryoablation versus radiofrequency ablation (RFA) versus AADs as a first line therapy of PAF. METHODS: MEDLINE, Embase, Scopus and CENTRAL were searched to retrieve randomized clinical trials (RCTs) comparing cryoablation, RFA or AADs to one another as first line therapies for atrial fibrillation (AF). The primary outcome was overall freedom from arrhythmia recurrence (AF, atrial flutter [AFL], atrial tachycardia). Secondary outcomes included freedom from symptomatic arrhythmia recurrence, hospitalization, and serious adverse events. A random-effects Bayesian network meta-analysis was used to calculate odds ratios (OR) and 95% credible intervals (CrI). RESULTS: Six RCTs (N = 1212) met the inclusion criteria (605 AADs, 365 Cryoablation, and 245 RFA). Compared with AADs, overall recurrence was reduced with RFA (OR: 0.31; 95% CrI: 0.10-0.71) and cryoablation (OR: 0.39; 95% CrI: 0.16-1.00). Comparing ablation (cryoablation and RFA) with AADs in respect to freedom from symptomatic AF recurrence, neither cryoablation (OR: 0.35; 95% CrI: 0.06-1.96) nor RFA (OR: 0.34; 95% CrI: 0.07-1.27) resulted in statistically significant reductions individually compared to AADs, though pooled ablation with both technologies showed lower odds of arrhythmia recurrence (OR: 0.35; 95% CrI: 0.13-0.79). In terms of serious adverse events rates, neither cryoablation (OR: 0.77; 95% CrI: 0.44-1.39) nor RFA (OR: 1.45; 95% CrI: 0.67-3.23) were significantly different to AADs. RFA resulted in a statistically significant reduction in hospitalizations compared to AAD (OR: 0.08; 95% CrI: 0.01-0.99), whereas cryoablation did not (OR: 0.77; 95% CrI: 0.44-1.39). The surface under the cumulative ranking curve showed RFA to be the most effective treatment at reducing overall rates of recurrence, symptomatic recurrence and hospitalizations; whereas cryoablation was most likely to reduce serious adverse events. CONCLUSION: Cryoablation and RFA are both effective and safe first line therapies for AF compared to AADs, with RFA being the most effective at reducing recurrences.

Impact of modulation bandwidth on multiplexing using principal modes in MMF links.

Multimode fibers (MMFs) are widely used for short fiber links. However, the data rates through MMFs is limited owing to modal dispersion. The so-called "principal modes" (PMs) permit transmission and multiplexing through the MMFs without modal dispersion for small modulation bandwidths. For larger modulation bandwidths, however, they lose their dispersion-free nature. In this paper, we model the impact of modulation bandwidth and mode coupling strength on the performance of PMs. We develop a simulator that characterizes the dispersion and cross-talk of the PMs of few-mode and large-core graded-index MMFs with mode-dependent losses (MDL). Simulations reveal that for fibers without MDL, for modulation frequencies beyond 10 GHz diminishes the PMs' frequency response by more than 1 dB for 100 m in large-core MMF links and 10 km few-mode fiber links. With MDL, simulations reveal that for modulation bandwidths beyond 2 GHz diminishes the frequency response by 3 dB for a 1 km few-mode fiber and by more than 4 dB for a 1 km large-core multimode fiber. While multiplexing using PMs in large-core MMFs with MDL, we find that for modulation bandwidths beyond 3 GHz, the cross-talk is 20 dB in 1 km large-core MMF links, thereby limiting system performance.

Post-myocardial Infarction Left Ventricular Aneurysm With Contained Rupture and Hemopericardium.

Left ventricular aneurysms (LVAs) represent a rare yet critical complication arising from late-presenting myocardial infarction (MI). Here, we present the case of an 88-year-old male with chest pressure, elevated troponin, B-type natriuretic peptide, and lactate. The electrocardiogram showed sinus tachycardia and an old right bundle branch block. The patient was started on heparin infusion, but progressively worsening hypotension necessitated transfer to the intensive care unit and the initiation of vasopressors. The echocardiogram identified a focal aneurysm in the mid-anterolateral wall, moderate pericardial effusion with a coagulum, and tamponade physiology. Computed tomography angiography of the chest confirmed a moderate pericardial effusion with density consistent with hemopericardium. LVAs pose a substantial threat of cardiovascular morbidity and mortality. While echocardiography serves as the initial assessment method, supplemental imaging modalities may need to be utilized. Various complications have been reported with LVA, including thromboembolization, ventricular arrhythmias, pericardial effusion with tamponade, and left ventricular rupture which accounts for 5%-24% of all in-hospital deaths related to MI. Although LVAs are the most common mechanical complications following an MI, instances of contained aneurysm rupture leading to hemopericardium are infrequent and scarcely reported. High clinical suspicion and prompt imaging with echocardiography are essential for diagnosis. Determining the optimal timing and selection between surgical and percutaneous interventions necessitates additional research for informed decision-making.

Transcatheter Vacuum-Assisted Mass Extraction Versus Surgical Debridement for Vegetations in Tricuspid Valve Infective Endocarditis: A Meta-Analysis of Observational Studies.

Tricuspid valve infective endocarditis (TVIE), often associated with vegetation in people who inject drugs, has introduced a less invasive option for vegetation removal: transcatheter vacuum-assisted mass extraction (TVME). This technique is emerging as an alternative to standard surgical debridement (SD) and valve repair. However, the comparative effectiveness of TVME versus SD in treating TVIE has yet to be investigated. A comprehensive systematic literature search was performed on PubMed, Embase, and Cochrane to identify all relevant studies comparing TVME with SD in patients with TVIE. The search covered studies from inception up to August 15, 2023. For data analysis, Review Manager (RevMan) 5.4 software was employed, using a random-effects model to calculate risk ratios (RRs), mean differences, and 95% confidence intervals (CIs). Five studies included a total of 431 patients (244 in the TVME arm and 187 in the SD arm). In-hospital mortality (p = 0.72), procedural mortality (p = 0.77), 30-day mortality (p = 0.25), and 1-year mortality (p = 0.44) insignificantly favored SD over TVME. Overall mortality across the 5 studies insignificantly favored TVME over SD (RR = 0.66, 95% CI 0.31 to 1.39, p = 0.27, I2 = 57%). When addressing heterogeneity by excluding 1 study, no statistical significance in the difference between the 2 arms regarding overall mortality was observed (RR 0.99, 95% CI 0.60 to 1.63, p = 0.97, I2 = 0%). This meta-analysis of the 5 observational studies found no significant difference in overall mortality between TVME and SD for the treatment of TVIE. However, prospective randomized controlled trials are necessary to further understand and compare the outcomes of these 2 approaches.

Pulmonary Artery Denervation as a New Therapeutic Option for Pulmonary Hypertension: A Systematic Review and Meta-Analysis.

Pulmonary hypertension (PH) is a progressive disease with a high morbidity and mortality. The treatment is based on the type of PH. Prognosis still remains poor despite the use of different medications. Pulmonary artery denervation (PADN) has been studied as a novel therapeutic option in these patients. PUBMED, EMBASE and COCHRANE databases were searched by 2 investigators until January 2023. Information was analyzed for the following outcomes: 6-minute walk distance (6MWD), mean pulmonary artery pressure, pulmonary vascular resistance and cardiac output. Subgroup analysis comparing pre and post PADN in different PH groups was done. Statistical analysis was performed with the Review Manager version 5.4. This meta- analysis included 6 controlled trials and 6 single-arm prospective studies with a total of 616 patients. Our pooled analysis showed a significant reduction in mean pulmonary artery pressure [WMD -6.51, 95% CI (-9.87, -3.15), p = 0.0001], pulmonary vascular resistance [WMD -3.69, 95% CI (-6.74, -0.64), p = 0.02] and increased cardiac output [WMD -0.37, 95% CI (0.08, 0.65), p = 0.01]. Subgroup analysis pre and post PADN demonstrated a significant improvement in 6MWD in the WHO group 1 [WMD 99.53, 95% CI (19.60, 179.47), p = 0.01], group 2 [WMD: 69.96, 95% CI (36.40, 103.51), p = < 0.0001] and group 4 [WMD: 99.54, 95% CI (21.80, 177.28), p = 0.01]. This meta-analysis supports PADN as a therapeutic option for patients with PH, regardless of group class. Further randomized trials are still needed to evaluate safety and efficacy.

Pacing-Induced Cardiomyopathy in Leadless and Traditional Pacemakers: A Single-Center Retrospective Analysis.

BACKGROUND:  Pacing-induced cardiomyopathy (PICM) is a clinical syndrome that is characterized by a drop in the left ventricular ejection fraction (LVEF) due to chronic high-burden right ventricular (RV) pacing. It has been postulated that leadless pacemakers (LPs) cause decreased risk of PICM compared to transvenous pacemakers (TVPs), but the exact risk reduction is unknown. METHODS: We performed a single-center retrospective analysis of adults who received an LP or TVP between January 1, 2014, and April 1, 2022, and had echocardiograms before and after the pacemaker implant. This study's outcomes were the RV pacing percentage, change in EF, the need for cardiac resynchronization therapy (CRT) upgrade, and follow-up duration. A Wilcoxon rank-sum test calculated the change in EF. RV time, defined as the duration from pacemaker placement to the follow-up echocardiogram in months multiplied by the RV pacing percentage, served as a surrogate for how long the RV was paced. RESULTS: A total of 614 patients were screened, and 198 patients were included in the study, where 72 received LP and 126 received TVP. The median follow-up was 480 days. The average of the reported RV percentage pacing was 63.43% for LP and 71.30% for TVP (p=0.14). The incidence of PICM and CRT upgrade was 44% and 9.7% in the LP group and 37% and 9.5% in the TVP group (p=0.3 and p>0.9), respectively. After accounting for age, sex, LP versus TVP, atrioventricular nodal ablation, RV pacing percentage, and follow-up duration, univariate analysis showed that RV time was significantly different between the two types of pacemakers (13.54 ± 14.21 months (LP) versus 9.26 ± 13.95 months (TVP), p=0.009). The difference in RV time between patients who underwent CRT upgrade and those who did not was statistically insignificant (12.11 ± 14.47 months (no CRT) versus 9.19 ± 12.00 months (CRT), p=0.5). CONCLUSIONS: This analysis demonstrated that the incidence of PICM was high in both groups (44% (LP) versus 37% (TVP)), despite significantly more RV time in patients with LP. There was no difference in CRT upgrade between LP and TVP.

Multi-organ dysfunction as a presentation of calcium channel blocker intoxication.

SummaryWe report the case of a 73-year-old woman who intentionally ingested 400 mg of amlodipine in a suicidal attempt who initially presented with hypotension which persisted despite aggressive therapy with fluid resuscitation, multiple pressor support, high-dose insulin therapy and calcium infusion. Her haemodynamic instability evolved to include bradycardia requiring atropine and transcutaneous pacing. Eventually she required salvage therapy with intravenous lipid emulsion (ILE) therapy . Despite all aggressive therapy, she developed multi-organ failure resulting in death. The literature on high-dose insulin euglycaemic therapy (HIET) and ILE therapy shows mixed results with some showing significant improvement in haemodynamic status. In our case, it had no significant positive impact on the outcome.

Structured, Timely, and Individualized Patient Feedback to Residents and its Effect on HCAHPS Scores.

Physician communication is integral for improving patients' experience and clinical outcomes. Hospital Consumer Assessment of Healthcare Providers and Systems (HCAHPS) scores are used by the Centers for Medicare & Medicaid Services to assess the quality of care provided to the patients. We conducted a prospective pre-post-intervention study from March 2018 to March 2020 and included patients and residents of the community-based university-affiliated Internal Medicine Residency Program. Residents' communication was evaluated through resident surveys and results were shared with them and attending physicians within 48 h. To correlate with the effect over a 4-year period, 839 HCAHPS surveys were obtained for attending physicians as an outcome measure. The mean overall HCAHPS score and doctor's communication scores increased by 8.52 and 6.06 points post-intervention. The doctor's performance score for respect increased by 6.18 points, listening increased by 3.12 points, and explanation increased by 8.23 points. This study demonstrates that timely, structured, and individualized resident feedback in an academic medicine service can result in a sustainable increase in the attendings' overall HCAHPS and doctor's communication scores.

Dermatologic Manifestation of Acro-Ischemia Associated With COVID-19.

Background: The common dermatologic manifestations seen in patients with coronavirus disease 2019 (COVID-19) include morbilliform, pernio-like, urticarial, macular erythematous, vesicular, and papulosquamous disorders, as well as retiform purpura. Although cases of acro-ischemia have been demonstrated, they are not well studied or reported. Case Report: A 73-year-old male was admitted for acute hypoxic respiratory failure secondary to COVID-19 infection. During the patient's hospital course, his oxygen requirement progressively increased, and he developed painful, violaceous purpura on his right lower extremity digits. The patient was treated with therapeutic doses of enoxaparin and nitroglycerin ointment in the hospital and apixaban on discharge. The patient was lost to follow-up. Conclusion: The multiorgan dysfunction associated with COVID-19 includes dermatologic manifestations. This case illustrates that acro-ischemia can resolve with guideline-based medical treatment.

Uncommon Cause of Internal Mammary Artery Pseudoaneurysm.

Background: Internal mammary artery pseudoaneurysms most commonly develop from thoracic penetrating trauma or procedures. However, other important etiologies should not be overlooked. Case Report: A 27-year-old female presented with antiphospholipid antibody syndrome, thrombotic microangiopathy, end-stage renal disease on hemodialysis, and epilepsy. On admission, the patient had pulseless electrical activity and hypertensive emergency. After the patient was successfully resuscitated, she developed status epilepticus. Laboratory workup on admission revealed a subtherapeutic international normalized ratio, elevated C-reactive protein and sedimentation rate, and acute anemia. Imaging showed a right-sided subdural hematoma with a midline shift and likely internal mammary artery pseudoaneurysm. Angiography demonstrated aneurysmal dilation, segmental narrowing, and a string of beads appearance. Because of our patient's demographics, string of beads appearance on diagnostic angiography, history of renal disease, and negative hepatitis serology, fibromuscular dysplasia was considered the etiology of the internal mammary artery pseudoaneurysm. The family opted for 2 burr holes and a subdural drain but declined further diagnostic and therapeutic interventions because of anoxic brain injury and poor prognosis. Conclusion: In this patient, the etiology of the internal mammary artery pseudoaneurysm was attributed to fibromuscular dysplasia. Although this patient's family chose comfort measures, treatment methods are available for internal mammary artery pseudoaneurysms.

Efficacy and Safety of Direct Oral Anticoagulants in Patients With Antiphospholipid Syndrome: A Systematic Review and Meta-Analysis.

Due to a high risk of recurrent thromboembolism in patients with antiphospholipid syndrome (APS), long-term anticoagulation is recommended. For decades, vitamin K antagonists (VKAs) have been the gold standard for thromboprophylaxis in these patients. Due to the widespread use of direct oral anticoagulants (DOACs) in various thromboembolic conditions and their potential advantages compared to VKAs, several studies have been conducted to evaluate their safety and efficacy in APS. We performed a literature search using PubMed, Embase, and Cochrane databases for studies comparing DOACs to VKAs in patients with APS. Relative risk (RR) and the corresponding 95% confidence intervals (95% CI) were estimated for recurrent thromboembolic events, bleeding, and mortality. A total of 1437 patients pooled from 12 studies were analyzed. The risk of recurrent thrombosis, especially arterial thrombosis, doubled with DOACs compared to VKAs (RR 2.61, 95% CI 1.44-4.71; p=0.001). The risk further increased in patients with a triple-positive antiphospholipid antibody profile (RR 4.50, 95% CI 1.91-10.63; p=0.0006) and with the use of rivaroxaban (RR 1.95, 95% CI 1.10-3.45; p=0.02). The risk of major bleeding and mortality were not significantly different between the two arms. A trend favoring DOACs compared to VKAs was observed for all bleeding events.  This meta-analysis comes in agreement with previous studies and supports the use of VKAs in APS. Our study revealed that VKAs remain the gold standard for the management of APS, especially triple-positive APS. DOACs, particularly rivaroxaban, are not as effective in preventing recurrent thromboembolism in high-risk APS patients. Further studies are needed to evaluate the role of DOACs apart from rivaroxaban with a focus on their efficacy in the management of isolated or double-positive APS.

Correlating Toe-Brachial Indices and Angiographically Confirmed Peripheral Artery Disease: A Retrospective Review.

In advanced peripheral arterial disease (PAD), medial arterial calcification is known to inflate the ankle-brachial index. An alternative method of evaluating symptomatic patients is toe-brachial indexes (TBI), where a ratio less than .7 indicates PAD and less than .4 indicates a severe form. The objective of this retrospective analysis was to investigate the association between TBIs less than .7 and angiographically verified PAD. Patients were required to have either a leg angiogram 13 months prior to or 12 months after a 6-minute walk test. Of the 174 included patients, the mean overall TBI was .450. The mean TBI by location was highest at iliac and infra-geniculate with .544 and lowest at supra-geniculate with .372. Infra-geniculate lesions were also the most frequent (n = 46). A TBI less than .4 was found in 47.7% of patients. TBIs greater than .7 were present in 36 patients; however, only 16 had significant angiographic stenosis. In conclusion, the majority of patients with angiographic PAD had a TBI less than .7, especially less than .4. Contrary to suspicion, infra-geniculate lesions were the most common and had the highest TBI.

Meta-Analysis Comparing Distal Radial Artery Approach Versus Traditional for Coronary Procedures.

Distal radial artery access (DRA) is recommended as the preferred approach over the traditional proximal radial artery access (TRA) for coronary procedures; however, there are limited randomized controlled trials (RCTs) that compared the 2. We conducted an updated meta-analysis of all RCTs from inception to July 26, 2021, that compared DRA versus TRA in patients who underwent coronary procedures. The statistical analysis was performed using a random effect model to calculate risk ratios (RRs) with 95% confidence intervals (CIs). A total of 5 RCTs were included with a total of 1,005 patients. A pooled analysis of the data showed that the rate of successful cannulation was similar between the 2 arms (RR 0.85, 95% CI 0.68 to 1.07, p = 0.16, I2 = 94%). The rate of radial artery spasm significantly favored the DRA arm as compared with TRA (RR 0.51, 95% CI 0.34 to 0.75, p = 0.0007, I2 = 0%). Significantly more patients from the DRA arm required alternative arterial access. Moreover, the DRA group had an insignificantly decreased rates of radial artery occlusion (RR 0.24, 95% CI 0.05 to 1.20, p = 0.08, I2 = 46%) and early discharge after transradial stenting of coronary arteries access-site hematomas (RR 0.52, 95% CI 0.18 to 1.149, p = 0.22, I2 = 0%). The mean time for hemostasis was significantly shorter in the DRA arm (mean difference -6.64, 95% CI -10.37 to -2.90, p = 0.0005, I2 = 88%). In conclusion, DRA should be considered as a viable, effective, and safe arterial access method for patients who underwent coronary procedures.

Left Atrial Appendage Closure During Cardiac Surgery for Atrial Fibrillation: A Meta-Analysis.

BACKGROUND: Left atrial appendage closure (LAAC) during cardiac surgery in atrial fibrillation (AF) patients has been investigated in multiple studies with variable safety and efficacy results. METHODS: A comprehensive review was performed of all studies comparing LAAC and placebo arm during cardiac surgery in AF patients. A random-effect model was used to calculate risk ratios, mean differences, and 95% confidence intervals. RESULTS: Five randomized controlled trials and 22 observational studies were included with a total of 540,111 patients. The LAAC group had significantly decreased postoperative stroke/embolic events as compared to the no LAAC group with all cardiac surgeries (3.74% vs 4.88%, p = 0.0002), isolated valvular surgery (1.95% vs 4.48%, p = 0.002). However, CABG insignificantly favored the LAAC group for stroke/embolic events (6.72% vs 8.30%, p = 0.07). There was no difference between both groups in all-cause mortality in the perioperative period (p = 0.42), but was significantly lower in the LAAC arm after two years (14.1% vs 18.3%, p = 0.02). There was no difference in major bleeding, all-cause rehospitalizations, or cross-clamp time between both groups (p = 0.53 and p = 0.45). The bypass and the cross-clamp time were longer in the LAAC group (4 and 9 min, respectively). CONCLUSION: In AF patients, LAAC during cardiac surgery had a decreased risk of stroke and long-term all-cause mortality. Additionally, there was no difference in major bleeding, all-cause rehospitalizations, or cross-clamp time.

Phrenic Nerve Palsy Following Radiation Therapy for Patient With Breast Cancer.

INTRODUCTION: Breast cancer is the most common malignancy affecting women in US today. Radiotherapy used after breast-conserving surgery has been shown to decrease local recurrence while minimizing side effects. Peripheral neuropathy remains a common and well-known complication of radiotherapy for breast cancer; however, it is rarely associated with phrenic nerve palsy after treatment of breast cancer. CASE PRESENTATION: We describe a 66-year-old woman with a significant past medical history of chronic obstructive pulmonary disease and asthma who presented with hypoxia after completing radiotherapy for breast cancer. After ruling out other causes of hypoxemia, the patient was diagnosed with diaphragmatic dysfunction, likely caused by phrenic nerve palsy resulting from radiotherapy-induced neuropathy after treatment of breast cancer. CONCLUSION: This case is the first reported incidence of phrenic nerve palsy resulting from radiotherapy for breast cancer.

Scombroid pancreatitis from mahi-mahi consumption.

A 61-year-old woman with no significant previous medical history presented to an urgent care facility with generalised rash, flushing and abdominal pain after eating mahi-mahi. She was diagnosed with an allergic reaction and discharged home. Later she experienced severe acute abdominal pain and multiple episodes of vomiting, which prompted her to go to the hospital. On admission, the patient had an elevated white count, lipase, amylase and C reactive protein with normal liver enzymes and bilirubin. Imaging showed acute pancreatitis that was suspected to be secondary to scombroid poisoning. This was confirmed by elevated immunoglobulin E and histamine levels. The acute pancreatitis was treated with pain management and supportive treatment. Scombroid poisoning is a well-recognised disease, however, acute pancreatitis secondary to this is rare as only two cases have been reported in the literature, one with codfish and the second an unknown type of fish.

Hypersensitivity Pneumonitis From Fire-Retardant Spray in a Patient With Multiple Lung Pathologies and Elevated Immunoglobulin E.

Background: Hypersensitivity pneumonitis, also known as extrinsic allergic alveolitis, is a pulmonary disease with large knowledge gaps, including etiology, pathogenesis, diagnosis, and treatment. Case Report: A 58-year-old male with a pertinent history of recurrent Mycobacterium malmoense presented to a tertiary emergency department after 1 week of difficulty breathing. He also reported a productive cough and fevers. The patient was an active smoker and was recently exposed to chemical fire-retardant spray. Chest x-ray showed extensive bilateral pulmonary infiltrates. The tertiary center initiated cefpodoxime 200 mg twice daily for 5 days and home azithromycin for possible pneumonia. However, the patient returned the next day with worsening symptoms. After the patient transferred to our institution, physical examination revealed a hypoxic patient with bibasilar crackles and wheezes. Laboratory tests revealed elevated white blood cell count, sedimentation rate, and immunoglobulin E. Chest computed tomography demonstrated growth of a previously noted right upper lobe intracavitary lesion and new onset diffuse interstitial pulmonary ground-glass airspace opacities. Hypersensitivity pneumonitis panel demonstrated positive antibodies to Aspergillus fumigatus antibody precipitin 1 and Micropolyspora faeni. The patient was given oral prednisone and advice on proper respiratory precautions in the workplace. Conclusion: This case illustrates that hypersensitivity pneumonitis can develop via chemical fire-retardant spray. Additionally, patients with a smoking history and elevated immunoglobulin E should be evaluated for severe forms of the disease.

Potential Role of Cardiopulmonary Exercise Testing as an Early Screening Tool for Patients With Suspected Pulmonary Hypertension Including Exercise-Induced Pulmonary Hypertension: Results From a Retrospective Analysis.

OBJECTIVE: The primary goal of our retrospective case-control study was to evaluate the ability of cardiopulmonary exercise testing to screen for underlying exercise-induced pulmonary hypertension (EIPH) in symptomatic patients who had a negative stress test and elevated right ventricular systolic pressure on echocardiogram. We also evaluated long-acting nitrates and ranolazine as medication challenges. SETTING: Performed at a single, tertiary-care medical center in the United States. PARTICIPANTS: Based on the inclusion and exclusion criteria, 81 patients were included in this study. The primary outcome of the study was to measure mean pulmonary arterial pressure at rest and exertion, as well as Wasserman curves. We also recorded patient demographics and risk factors, left ventricular ejection fraction, and mean oxygen consumption. Additionally, patients were monitored symptomatically after receiving long-acting nitrates and ranolazine. RESULTS: A total of 61 patients had resting pulmonary arterial hypertension, and 27 had EIPH. The EIPH group had a significantly higher mean age of 71.67 years. Wasserman curves calculated from the cardiopulmonary exercise testing data revealed 3 subgroups of EIPH patients: cardiac restriction, chronotropic incompetence, and combination of both patterns. The EIPH group showed significant improvement in symptoms after receiving long-acting nitrate therapy. CONCLUSIONS: Many patients with symptoms of angina, dyspnea, and/or fatigue on exertion with negative cardiac stress testing may have underlying pulmonary arterial hypertension, including EIPH. Therefore, these patients require adequate treatment and follow-up to prevent worsening of symptoms and pathology.

Case Report of High-Grade Atrioventricular Block and Takotsubo Cardiomyopathy.

INTRODUCTION: Takotsubo cardiomyopathy (TTC) is a condition with a good long-term prognosis. However, when the TTC is due to a life-threatening arrhythmia, such as atrioventricular block (AVB), several considerations must be made regarding treatment. CASE PRESENTATION: A 71-year-old woman with a history of ischemic stroke presented after a syncopal episode. Before passing out, the patient was walking, nauseous, lightheaded, dizzy, and short of breath. In the emergency department, the blood pressure was 230/120 mmHg, and the heart rate was 38 beats per minute, but the patient was asymptomatic. An electrocardiogram showed a new-onset 2:1 AVB, bifascicular block, and prolonged PR and corrected QT intervals. An echocardiogram revealed a new-onset ejection fraction of 30% to 35%; hypokinesis of the apex, mid-inferoseptum, mid-anterolateral, apical to mid-inferior, and apical to mid-anterior walls; and hyperkinesis of the basal segments. The cardiac catheterization illustrated normal coronary arteries without significant stenosis. Therefore, the patient was diagnosed with TTC and 2:1 AVB. She was treated with lisinopril and metoprolol succinate and received a dual-chamber pacemaker. At the follow-up visit, the patient's ejection fraction and hypokinetic segments improved. She denied any recurrence of syncope, and her pacemaker was functioning appropriately. CONCLUSION: When AVB or other arrhythmias initiate a TTC, the patient can experience sudden cardiac death and decompensate quickly. Therefore, clinicians should understand this rare but fatal complication because these patients require pacemakers and beta blockers.

Effect of Immunosuppressive Diseases and Rituximab Infusions on Allowing COVID-19 Infection to Relapse.

INTRODUCTION: Relapsing COVID-19 infections have been reported, but their etiology and severity are still unknown. In addition, there have been no cases in the literature that associate relapsing infection with immunosuppression, either from a disease course or medications. CASE PRESENTATION: This case series illustrates two patients who developed a relapsed infection, likely from recent rituximab infusions. In addition, both cases depicted a severe form of infection than the initial one. Laboratory investigations revealed these patients were unable to produce COVID-19 antibodies, even though one of the patients received convalescent plasma. CONCLUSION: Clinicians should be aware of the possibility of relapsing COVID-19, especially in immunosuppressed patients. Because rituximab induces B-cell depletion, it can also decrease the effectiveness of the COVID-19 vaccine. Therefore, these patients should receive the vaccine before their scheduled rituximab infusion.