Pathophysiology and Acute Management of Tachyarrhythmias in Pheochromocytoma: JACC Review Topic of the Week

Atrial fibrillation in cancer, anticancer therapies, and underlying mechanisms

Atrial fibrillation (AF) is a common arrhythmic complication in cancer patients and can be exacerbated by traditional cytotoxic and targeted anticancer therapies. Increased incidence of AF in cancer patients is independent of confounding factors, including preexisting myocardial arrhythmogenic substrates, type of cancer, or cancer stage. Mechanistically, AF is characterized by fast unsynchronized atrial contractions with rapid ventricular response, which impairs ventricular filling and results in various symptoms such as fatigue, chest pain, and shortness of breath. Due to increased blood stasis, a consequence of both cancer and AF, concern for stroke increases in this patient population. To compound matters, cardiotoxic anticancer therapies themselves promote AF; thereby exacerbating AF morbidity and mortality in cancer patients. In this review, we examine the relationship between AF, cancer, and cardiotoxic anticancer therapies with a focus on the shared molecular and electrophysiological mechanisms linking these disease processes. We also explore the potential role of sodium-glucose co-transporter 2 inhibitors (SGLT2i) in the management of anticancer-therapy-induced AF.

Approach to the Patient: Concept and Application of Targeted Radiotherapy in the Paraganglioma Patient

Paragangliomas can metastasize, posing potential challenges both in symptomatic management and disease control. Systemic targeted radiotherapies using 131I-MIBG and 177Lu-DOTATATE are a mainstay in the treatment of metastatic paragangliomas. This clinical scenario and discussion aim to enhance physicians' knowledge of the stepwise approach to treat these patients with paraganglioma-targeted radiotherapies. It comprehensively discusses current approaches to selecting paraganglioma patients for targeted radiotherapies and how to choose between the two radiotherapies based on specific patient and tumor characteristics, when either therapy is feasible, or one is superior to another. The safety, efficacy, toxicity profiles, and optimization of these radiotherapies are also discussed, along with other therapeutic options including radiotherapies, available for patients besides these two therapies. Perspectives in radiotherapies of paraganglioma patients are outlined since they hold promising approaches in the near future that can improve patient outcomes.

A Case Report and Literature Review of Pheochromocytoma Without Tachycardia

This case report highlights a 47-year-old woman with an adrenal incidentaloma and a history of polysubstance abuse, finally diagnosed with pheochromocytoma. Characterized by episodic hypertension, headaches, and palpitations, pheochromocytoma is a rare condition with potential complications like uncontrolled hypertension and heart failure. Remarkably, during her 28-day hospitalization, continuous monitoring revealed no instances of tachycardia or arrhythmias despite multiple symptomatic episodes. This finding aligns with reports that while 50-70% of symptomatic pheochromocytoma patients experience palpitations, only about 20% exhibit detectable tachycardia or arrhythmias. This discrepancy suggests varied individual cardiovascular responses to catecholamine surges, possibly due to differences in catecholamine inactivation rates and receptor sensitivity. This case underscores the complexity of pheochromocytoma symptoms and highlights the need for personalized diagnostic and management strategies. Furthermore, it points to a significant gap in understanding the correlation between palpitations and arrhythmia in pheochromocytoma, indicating a critical area for future research.

Multifunctional cardiac microphysiological system based on transparent ITO electrodes for simultaneous optical measurement and electrical signal monitoring

Drug-induced cardiotoxicity is a significant contributor to drug recalls, primarily attributed to limitations in existing drug screening platforms. Traditional heart-on-a-chip platforms often employ metallic electrodes to record cardiomyocyte electrical signals. However, this approach hinders direct cardiomyocyte morphology observation and typically yields limited functionality. Consequently, this limitation may lead to an incomplete understanding of cardiomyocyte characteristics. To address these challenges, we introduce a multifunctional cardiac microphysiological system featuring transparent indium tin oxide electrodes. This innovative design aims to overcome the limitations of conventional heart-on-a-chip systems where metal electrodes interfere with the observation of cells and increase the difficulty of subsequent image processing of cell images. In addition to facilitating optical measurement combined with image processing capabilities, this system integrates a range of electrodes with diverse functionalities. These electrodes can realize cellular electrical stimulation, field potential monitoring, and impedance change tracking, enabling a comprehensive investigation of various cardiomyocyte traits. To demonstrate its versatility, we investigate the effects of four cardiac drugs with distinct pharmacological profiles on cardiomyocytes using this system. This platform provides a means for quantitatively and predictively assessing cardiac toxicity, which could be applied to conduct a comprehensive evaluation during the drug discovery process.

Management of phaeochromocytoma and paraganglioma in patients with germline SDHB pathogenic variants: an international expert Consensus statement

Adult and paediatric patients with pathogenic variants in the gene encoding succinate dehydrogenase (SDH) subunit B (SDHB) often have locally aggressive, recurrent or metastatic phaeochromocytomas and paragangliomas (PPGLs). Furthermore, SDHB PPGLs have the highest rates of disease-specific morbidity and mortality compared with other hereditary PPGLs. PPGLs with SDHB pathogenic variants are often less differentiated and do not produce substantial amounts of catecholamines (in some patients, they produce only dopamine) compared with other hereditary subtypes, which enables these tumours to grow subclinically for a long time. In addition, SDHB pathogenic variants support tumour growth through high levels of the oncometabolite succinate and other mechanisms related to cancer initiation and progression. As a result, pseudohypoxia and upregulation of genes related to the hypoxia signalling pathway occur, promoting the growth, migration, invasiveness and metastasis of cancer cells. These factors, along with a high rate of metastasis, support early surgical intervention and total resection of PPGLs, regardless of the tumour size. The treatment of metastases is challenging and relies on either local or systemic therapies, or sometimes both. This Consensus statement should help guide clinicians in the diagnosis and management of patients with SDHB PPGLs.

The diagnostic approach and management of hypertension in the emergency department

Hypertension urgency and emergency represents a challenging condition in which clinicians should determine the assessment and/or treatment of these patients. Whether the elevation of blood pressure (BP) levels is temporary, in need of treatment, or reflects a chronic hypertensive state is not always easy to unravel. Unfortunately, current guidelines provide few recommendations concerning the diagnostic approach and treatment of emergency department patients presenting with severe hypertension. Target organ damage determines: the timeframe in which BP should be lowered, target BP levels as well as the drug of choice to use. It's important to distinguish hypertensive emergency from hypertensive urgency, usually a benign condition that requires more likely an outpatient visit and treatment.

Catecholamine-induced hypertensive crises: current insights and management

Phaeochromocytomas and paragangliomas (PPGLs) release catecholamines leading to catecholamine-induced hypertensive (CIH) crises, with blood pressure greater than or equal to 180/120 mm Hg. CIH crises can be complicated by tachyarrhythmias, hypotension, or life-threatening target organ damage while treatment remains undefined, often requiring co-management between endocrinologists and cardiologists. Furthermore, biochemical diagnosis of a PPGL as a cause of a CIH crisis can be difficult to identify or confounded by comorbid conditions, potentially resulting in misdiagnosis. Here, we combine relevant evidence, 60 years of collective clinical experience, insights derived from assessing over 2600 patients with PPGL, and supplementary outcomes from 100 patients (treated at the National Institutes of Health) with a CIH crisis to inform diagnosis and treatment of CIH crises. Recognising that disparities exist between availability, cost, and familiarity of various agents, flexible approaches are delineated allowing for customisation, given institutional availability and provider preference. A CIH crisis and its complications are readily treatable with available drugs, with effective intervention defining an avenue for mitigating consequent morbidity and mortality in patients with PPGL.

Pacak-Zhuang syndrome: a model providing new insights into tumor syndromes

This article is a summary of the plenary lecture presented by Jared Rosenblum that was awarded the Manger Prize at the Sixth International Symposium on Pheochromocytoma/Paraganglioma held on 19-22 October 2022 in Prague, Czech Republic. Herein, we review our initial identification of a new syndrome of multiple paragangliomas, somatostatinomas, and polycythemia caused by early postzygotic mosaic mutations in EPAS1, encoding hypoxia-inducible factor 2 alpha (HIF-2α), and our continued exploration of new disease phenotypes in this syndrome, including vascular malformations and neural tube defects. Continued recruitment and close monitoring of patients with this syndrome as well as the generation and study of a corresponding disease mouse model as afforded by the pheochromocytoma/paraganglioma translational program at the National Institutes of Health has provided new insights into the natural history of these developmental anomalies and the pathophysiologic role of HIF-2α. Further, these studies have highlighted the importance of the timing of genetic defects in the development of related disease phenotypes. The recent discovery and continued study of this syndrome has not only rapidly evolved our understanding of pheochromocytoma and paraganglioma but also deepened our understanding of other developmental tumor syndromes, heritable syndromes, and sporadic diseases.

Paediatric phaeochromocytoma and paraganglioma: A clinical update

Paediatric phaeochromocytomas and paragangliomas (PPGLs), though rare tumours, are associated with significant disability and death in the most vulnerable of patients early in their lives. However, unlike cryptogenic and insidious disease states, the clinical presentation of paediatric patients with PPGLs can be rather overt, allowing early diagnosis, granted that salient findings are recognized. Additionally, with prompt and effective intervention, prognosis is favourable if timely intervention is implemented. For this reason, this review focuses on four exemplary paediatric cases, succinctly emphasizing the now state-of-the-art concepts in paediatric PPGL management.

Pheochromocytoma/paraganglioma-associated cardiomyopathy

Pheochromocytoma/paraganglioma (PPGL) are neuroendocrine tumors that frequently produce and release catecholamines. Catecholamine excess can manifest in several cardiovascular syndromes, including cardiomyopathy. PPGL-induced cardiomyopathies occur in up to 11% of cases and are most often associated with an adrenal pheochromocytoma (90%) and rarely with a paraganglioma derived from the sympathetic ganglia (10%). PPGL-associated cardiomyopathies can be chronic or acute, with takotsubo cardiomyopathy being the most often reported. These two types of PPGL-induced cardiomyopathy seem to have different pathophysiological backgrounds. Acute catecholaminergic stress inundates myocardial β-adrenoceptors and leads to left ventricle stunning and slight histological apoptosis. In chronic cardiomyopathy, prolonged catecholamine exposure leads to extended myocardial fibrosis, inflammation, and necrosis, and ultimately it causes dilated cardiomyopathy with a low ejection fraction. Sometimes, especially in cases associated with hypertension, hypertrophic cardiomyopathy can develop. The prognosis appears to be worse in chronic cases with a higher hospital mortality rate, higher cardiogenic shock rate at initial presentation, and lower left ventricular recovery rate after surgery. Therefore, establishing the correct diagnosis at an early stage of a PPGL is essential. This mini-review summarizes current data on pathophysiological pathways of cardiac damage caused by catecholamines, the clinical presentation of PPGL-induced cardiomyopathies, and discusses treatment options.

Cardiopatía isquémica como forma de presentación de feocromocitoma

Pheochromocytoma is a rare cause of ischaemic heart disease. We present the case of a patient in whom pheochromocytoma was diagnosed following ischaemic heart disease with absence of coronary lesions, demonstrating the importance of taking it into account in the differential diagnosis in these cases, especially considering that curative treatment is available.

New Biology of Pheochromocytoma and Paraganglioma

Pheochromocytomas and paragangliomas continue to be defined by significant morbidity and mortality despite their several recent advances in diagnosis, localization, and management. These adverse outcomes are largely related to mass effect as well as catecholamine-induced hypertension, tachyarrhythmias and consequent target organ damage, acute coronary syndromes, and strokes (ischemic and hemorrhagic stroke). Thus, a proper understanding of the physiology and pathophysiology of these tumors and recent advances are essential to affording optimal care. These major developments largely include a redefinition of metastatic behavior, a novel clinical categorization of these tumors into 3 genetic clusters, and an enhanced understanding of catecholamine metabolism and consequent specific biochemical phenotypes. Current advances in imaging of these tumors are shifting the paradigm from poorly specific anatomical modalities to more precise characterization of these tumors using the advent and development of functional imaging modalities. Furthermore, recent advances have revealed new molecular events in these tumors that are linked to their genetic landscape and, therefore, provide new therapeutic platforms. A few of these prospective therapies translated into new clinical trials, especially for patients with metastatic or inoperable tumors. Finally, outcomes are ever-improving as patients are cared for at centers with cumulative experience and well-established multidisciplinary tumor boards. In parallel, these centers have supported national and international collaborative efforts and worldwide clinical trials. These concerted efforts have led to improved guidelines collaboratively developed by healthcare professionals with a growing expertise in these tumors and consequently improving detection, prevention, and identification of genetic susceptibility genes in these patients.

Incidence and risk factors for myocardial injury after laparoscopic adrenalectomy for pheochromocytoma: A retrospective cohort study

Background

Pheochromocytoma is a rare catecholamine-secreting tumor. Tumor resection remains a high-risk procedure due to intraoperative hemodynamic instability nowadays, which may lead to myocardial injury. We aimed to determine the incidence and associated risk factors for myocardial injury after laparoscopic adrenalectomy for pheochromocytoma.

Methods

Adult patients (n=350, American Society of Anesthesiology physical status 1–3) who underwent elective laparoscopic adrenalectomy for pheochromocytoma under general anesthesia between January 31, 2013 and January 31, 2020 were included in this observational, retrospective, single-center, cohort study. Blood troponin I levels were measured before and during the first 2 days after surgery. Myocardial injury was defined as an elevated troponin I level exceeding the 99th percentile upper reference limit due to cardiac ischemic causes.

Results

Myocardial injury occurred in 42/350 patients (12.0%, 95% confidence interval: 9.0%–15.9%). In multivariable analysis (adjusted odds ratios [95% confidence intervals]), previous ischemic heart disease or stroke (5.04 [1.40–18.08]; P=0.013), intraoperative heart rate >115 bpm (2.55 [1.06–6.12]; P=0.036), intraoperative systolic blood pressure >210 mmHg (2.38 [1.00–5.66]; P=0.049), and perioperative decrease in hemoglobin level(1.74 [1.15–2.64] per g/dL decrease; P=0.008) were associated with an increased risk of myocardial injury. For the cumulative duration of dichotomized intraoperative hemodynamics, multivariable analysis showed that intraoperative heart rate >115 bpm for >1 minute (2.67 [1.08–6.60]; P=0.034) and systolic blood pressure >210 mmHg for >1 minute (3.78 [1.47–9.73]; P=0.006) were associated with an increased risk of myocardial injury. The risk of myocardial injury progressively increased with a longer cumulative duration of intraoperative tachycardia and hypertension.

Conclusions

There is a high incidence of myocardial injury after laparoscopic adrenalectomy for pheochromocytoma. The identified risk factors may assist physicians in detecting high-risk patients and providing guidance for intraoperative hemodynamics and perioperative hemoglobin management.

Sinus Tachycardia: a Multidisciplinary Expert Focused Review

Sinus tachycardia (ST) is ubiquitous, but its presence outside of normal physiological triggers in otherwise healthy individuals remains a commonly encountered phenomenon in medical practice. In many cases, ST can be readily explained by a current medical condition that precipitates an increase in the sinus rate, but ST at rest without physiological triggers may also represent a spectrum of normal. In other cases, ST may not have an easily explainable cause but may represent serious underlying pathology and can be associated with intolerable symptoms. The classification of ST, consideration of possible etiologies, as well as the decisions of when and how to intervene can be difficult. ST can be classified as secondary to a specific, usually treatable, medical condition (eg, pulmonary embolism, anemia, infection, or hyperthyroidism) or be related to several incompletely defined conditions (eg, inappropriate ST, postural tachycardia syndrome, mast cell disorder, or post-COVID syndrome). While cardiologists and cardiac electrophysiologists often evaluate patients with symptoms associated with persistent or paroxysmal ST, an optimal approach remains uncertain. Due to the many possible conditions associated with ST, and an overlap in medical specialists who see these patients, the inclusion of experts in different fields is essential for a more comprehensive understanding. This article is unique in that it was composed by international experts in Neurology, Psychology, Autonomic Medicine, Allergy and Immunology, Exercise Physiology, Pulmonology and Critical Care Medicine, Endocrinology, Cardiology, and Cardiac Electrophysiology in the hope that it will facilitate a more complete understanding and thereby result in the better care of patients with ST.

A novel role of FoxO3a in the migration and invasion of trophoblast cells: from metabolic remodeling to transcriptional reprogramming

Background

The forkhead box O3a protein (FoxO3a) has been reported to be involved in the migration and invasion of trophoblast, but its underlying mechanisms unknown. In this study, we aim to explore the transcriptional and metabolic regulations of FoxO3a on the migration and invasion of early placental development.

Methods

Lentiviral vectors were used to knock down the expression of FoxO3a of the HTR8/SVneo cells. Western blot, matrigel invasion assay, wound healing assay, seahorse, gas-chromatography-mass spectrometry (GC–MS) based metabolomics, fluxomics, and RNA-seq transcriptomics were performed.

Results

We found that FoxO3a depletion restrained the migration and invasion of HTR8/SVneo cells. Metabolomics, fluxomics, and seahorse demonstrated that FoxO3a knockdown resulted in a switch from aerobic to anaerobic respiration and increased utilization of aromatic amino acids and long-chain fatty acids from extracellular nutrients. Furthermore, our RNA-seq also demonstrated that the expression of COX-2 and MMP9 decreased after FoxO3a knockdown, and these two genes were closely associated with the migration/invasion progress of trophoblast cells.

Conclusions

Our results suggested novel biological roles of FoxO3a in early placental development. FoxO3a exerts an essential effect on trophoblast migration and invasion owing to the regulations of COX2, MMP9, aromatic amino acids, energy metabolism, and oxidative stress.

An Unusual Presentation of Paroxysmal Atrial Fibrillation Following Ablation

A pheochromocytoma is a rare catecholamine-secreting tumor with an incidence of 0.8 per 100,000 person-years. Classic clinical manifestations include episodic headache, sweating, and tachycardia. This case report shares a unique presentation in which a patient with a history of atrial fibrillation status post-ablation procedure was admitted for chest pain and found to have imaging and laboratory findings consistent with pheochromocytoma. This case illustrates the importance of a high clinical index of suspicion for a pheochromocytoma since it can have a variety of clinical presentations and can result in unnecessary procedures.

Supportive management of patients with pheochromocytoma/paraganglioma undergoing noninvasive treatment

PURPOSE OF REVIEW

Many publications review perioperative management of pheochromocytomas/paragangliomas (PPGLs); however, a large population, including 10-20% of metastatic PPGL patients, have inoperable disease. This has necessitated the development of noninvasive treatments (e.g., radio/chemotherapy), which, in affording disease-modification, have led to an ever-growing population of surviving patients with inoperable PPGL. These patients experience debilitating symptoms arising from discomforts related to the masses themselves (e.g., pain from osseous metastasis) and symptoms from tumoral catecholamine production and release. Unfortunately, management of these conditions is not yet well-defined. Adding further insult-to-injury, these noninvasive treatments can trigger catecholamine release, worsening catecholamine-induced symptoms. Herein, we detail these ailments and their management, especially while patients receive these noninvasive treatments.

RECENT FINDINGS

Improved diagnostic evaluations have allowed for earlier detection of PPGL, prolonging survival in patients with inoperable PPGLs. Accordingly, noninvasive treatment strategies have rapidly evolved alongside state-of- the-art theranostics and genetic testing, which inform ongoing management and therapeutic response.

SUMMARY

While treatments afford improved survival, there must be a corresponding attention to quality-of-life. This is ensured by employing supportive management, which mitigates debilitating symptoms. This is best accomplished with a multidisciplinary approach and familiarity with genetic and biochemical determinants which guide patient education and management.

An Interesting Case of Treatment-Resistant Ventricular Tachycardia Secondary to Pheochromocytoma and Left Ventricular Non-compaction

A 51-year-old patient was admitted with chest pain and broad complex ventricular tachycardia. He received three consecutive direct cardioversion (DC) shocks and was commenced on amiodarone infusion via a central venous catheter or central line (CVC). He responded to treatment and normal sinus rhythm (NSR) was achieved. He had elevated troponin I and underwent coronary angiogram which initially was thought to be responsible for his ventricular tachycardia. Coronary angiogram (CAG) showed unobstructed coronary arteries. He was recently diagnosed with pheochromocytoma and was commenced on Phenoxybenzamine 10 mg two months back. He developed ventricular tachycardia (VT) again the next day that did not respond to four consecutive direct cardioversion shocks (DC) and antiarrhythmic medications. He was intubated and ventilated to terminate his VT and was transferred to the intensive care unit (ICU). He remained intubated for 48 hours and he remained in NSR, after which he was extubated. He was commenced on bisoprolol and was later stepped down to the coronary care unit (CCU). Cardiac magnetic resonance imaging (CMR) showed left ventricular non-compaction (LVNC) or possibly myocarditis in view of patient's known history of pheochromocytoma. He was discussed with surgical team at another hospital for surgical resection of the adrenal tumor and had a few further runs of VT while he was waiting to be transferred. The patient finally underwent surgical resection of the tumor and was booked for implantable cardioverter defibrillator (ICD) in view of his VT. This was an interesting case of treatment-resistant VT driven by pheochromocytoma and LVNC, and it is important to be familiar with the fact that conventional therapies may fail in these patients and may require intubation and ventilation to terminate VT storms.

The association between the type of anesthesia and hemodynamic instability during pheochromocytoma surgery: a retrospective cohort study

BACKGROUND

Pheochromocytoma often carries a risk for perioperative hemodynamic instability (HDI). The aim of this study is to evaluate the risk factors of intraoperative HDI during minimally invasive posterior retroperitoneal adrenalectomy (PRA) for pheochromocytoma.

MATERIALS AND METHODS

This retrospective study analyzed the prospectively collected data of 172 patients who underwent laparoscopic PRA or robotic PRA for pheochromocytoma between January 2014 and December 2020 at a single tertiary center. The patients were divided into two groups according to the intraoperative hypertensive event of systolic blood pressure (> 160 mmHg). The clinical manifestations and perioperative hemodynamic conditions were analysed.

RESULTS

In the multivariate logistic regression analysis, the tumor size (> 3.4 cm) [OR 3.14, 95% confidence intervals (CI) (1.48-6.64), p = 0.003], type of preoperative alpha-blocker (selective type) [OR 3.9, 95% CI (1.52-10.02), p = 0.005], preoperative use of beta-blockers [OR 3.94, 95% CI (1.07-14.49), p = 0.039] and type of anesthesia [total intravenous anesthesia (TIVA) vs. balanced anesthesia (BA)] [OR 2.57, 95% CI (1.23-5.38), p = 0.012] were determined as independent risk factors of intraoperative hypertensive events during minimally invasive adrenalectomy.

CONCLUSIONS

The type of anesthesia was independently associated with intraoperative HDI along with larger tumor size, type of preoperative alpha-blocker and the use of preoperative beta-blockers. TIVA increased the risk of intraoperative hypertensive events compared with BA. Thus, the consideration of the type of anesthesia prior to adrenal surgery for pheochromocytoma along with the use of preoperative non-selective alpha-blockers may be beneficial in minimizing the risk of intraoperative HDI.

Pediatric Metastatic Pheochromocytoma and Paraganglioma: Clinical Presentation and Diagnosis, Genetics, and Therapeutic Approaches

Although pediatric pheochromocytomas and paragangliomas (PPGLs) are rare, they have important differences compared to those in adults. Unfortunately, without timely diagnosis and management, these tumors have a potentially devastating impact on pediatric patients. Pediatric PPGLs are more often extra-adrenal, multifocal/metastatic, and recurrent, likely due to these tumors being more commonly due to a genetic predisposition than in adults. This genetic risk results in disease manifestations at an earlier age giving these tumors time to advance before detection. In spite of these problematic features, advances in the molecular and biochemical characterization of PPGLs have heralded an age of increasingly personalized medicine. An understanding of the genetic basis for an individual patient's tumor provides insight into its natural history and can guide clinicians in management of this challenging disease. In pediatric PPGLs, mutations in genes related to pseudohypoxia are most commonly seen, including the von Hippel-Lindau gene (VHL) and succinate dehydrogenase subunit (SDHx) genes, with the highest risk for metastatic disease associated with variants in SDHB and SDHA. Such pathogenic variants are associated with a noradrenergic biochemical phenotype with resultant sustained catecholamine release and therefore persistent symptoms. This is in contrast to paroxysmal symptoms (e.g., episodic hypertension, palpitations, and diaphoresis/flushing) as seen in the adrenergic, or epinephrine-predominant, biochemical phenotype (due to episodic catecholamine release) that is commonly observed in adults. Additionally, PPGLs in children more often present with signs and symptoms of catecholamine excess. Therefore, children, adolescents, and young adults present differently from older adults (e.g., the prototypical presentation of palpitations, perspiration, and pounding headaches in the setting of an isolated adrenal mass). These presentations are a direct result of genetic determinants and highlight the need for pediatricians to recognize these differences in order to expedite appropriate evaluations, including genetic testing. Identification and familiarity with causative genes inform surveillance and treatment strategies to improve outcomes in pediatric patients with PPGL.

Case report: Incidentally discovered case of pheochromocytoma as a cause of long COVID-19 syndrome

Pheochromocytomas (PCCs) are rare but potentially lethal tumors that arise from the adrenal medulla. The clinical suspicion and diagnosis of PCC can be challenging due to the non-specific nature of signs and symptoms. In many patients, infection with severe acute respiratory syndrome coronavirus 2 (SARS-CoV-2) could lead to long-term symptoms including fatigue, headaches, and cognitive dysfunction. Here, we present the case of a patient incidentally diagnosed with an adrenal mass that proved to be a PCC after imaging was performed due to persisting complaints after coronavirus disease 2019 (COVID-19) infection. A 37-year-old male patient was referred to our center because of a right-sided inhomogeneous adrenal mass, incidentally found during a computed tomographic scan of the thorax performed due to cough and dyspnea that persisted after COVID-19 infection. Other complaints that were present prior to COVID-19 infection included profuse sweating, dizziness, exhaustion with chronic fatigue, and concentration difficulties. The patient had no history of hypertension, his blood pressure was normal, and the 24-h ambulatory blood pressure monitoring confirmed normotension but with the absence of nocturnal dipping. Plasma normetanephrine was 5.7-fold above the upper limit (UL) of reference intervals (738 pg/ml, UL = 129 pg/ml), whereas plasma metanephrine and methoxytyramine were normal at 30 pg/ml (UL = 84 pg/ml) and <4 pg/ml (UL = 16 pg/ml), respectively. Preoperative preparation with phenoxybenzamine was initiated, and a 4-cm tumor was surgically resected. Profuse sweating as well as dizziness was resolved after adrenalectomy pointing toward PCC and not COVID-19-associated patient concerns. Altogether, this case illustrates the difficulties in recognizing the possibility of PCC due to the non-specific nature of signs and symptoms of the tumor, which in this case did not include hypertension and coincided with some of the symptoms of long COVID-19.

Adrenal bleeding due to pheochromocytoma - A call for algorithm

BACKGROUND

Adrenal hemorrhage is a rare, usually life-threating complication. The most common neoplasm resulting in spontaneous adrenal bleeding is pheochromocytoma and it accounts for nearly 50% of cases. Currently, the recommendations for the diagnosis and management of patients with adrenal bleeding due to pheochromocytoma are unavailable.

MATERIALS AND METHODS

We performed a database search for all pheochromocytoma patients, diagnosed and treated from 2005 to 2021 in tertiary endocrinology center. 206 patients were identified, 183 with complete data were included in the analysis. We investigated clinicopathological characteristics, treatment and outcomes of hemorrhagic pheochromocytoma cases and characterize our approach to perioperative diagnosis and medical management. Finally our experiences and data from previously published articles concerning adrenal hemorrhage were analyzed to propose a diagnostic and therapeutic algorithm for hemorrhagic pheochromocytomas.

RESULTS

In the whole group, seven patients (4 men and 3 women) with adrenal bleeding were found, (3.8%). Median patient's age was 49 years (range: 36-78 years). The most common manifestation of adrenal bleeding was acute abdominal pain (5/7). Two patients developed shock. Hormonal assessment was performed in five patients, based on 24-hour urinary fractionated metanephrines with urinary 3-methoxytyramine. Normetanephrine was elevated in all patients, metanephrine and 3-methoxytyramine - in four cases (4/5). Most patients (6/7) had symptoms suggesting pheochromocytoma before hemorrhage - most commonly paroxysmal hypertension (4/7). One patient died, before the diagnosis of adrenal bleeding was made. Diagnostic imaging performed in six out of seven patients revealed adrenal tumor, with median largest diameter equal to 7.4 cm (range: 5-11 cm). Five patients had elective surgery, in one case an urgent surgery was performed. In all cases the diagnosis of pheochromocytoma was confirmed in postoperative histopathology or in autopsy. The perioperative survival rate was 85.7%.

CONCLUSIONS

Diagnosis of pheochromocytoma should be always considered in patients with adrenal bleeding, especially with accompanying abdominal pain, hemodynamic shock and previous history of pheochromocytoma-associated symptoms. Lack of proper diagnosis of pheochromocytoma before surgery is associated with an additional perioperative risk. To improve the decision making in this life-threatening clinical situation, based on our results and literature data, we proposed a diagnostic and treatment algorithm.

Protocol for presurgical and anesthetic management of pheochromocytomas and sympathetic paragangliomas: a multidisciplinary approach

OBJECTIVE

To offer a practical guide for the presurgical and anesthetic management of pheochromocytomas and sympathetic paragangliomas (PGLs).

METHODS

This protocol was based on a comprehensive review of the literature and on our own multidisciplinary team's experience from managing pheochromocytoma and sympathetic PGLs at a referral center.

RESULTS

Patients with pheochromocytomas and sympathetic paragangliomas (PGLs) may develop potentially life-threatening complications, especially during surgical procedures. A complete biochemical, radiological, genetic, and cardiological assessment is recommended in the preoperative stage as it provides an evaluation of the risk of surgical complications and malignancy, allowing individualization of the presurgical treatment. Treatment with α-blockade and proper volume expansion in the preoperative stage significantly reduces the perioperative morbidity. During surgery, the anesthesiologist should look for a deep anesthetic level that inhibits the cardiovascular effects of catecholamines to minimize the risk of intraoperative complications.

CONCLUSIONS

An optimal presurgical evaluation of pheochromocytomas/ sympathetic PGL requires a multidisciplinary approach, including a complete hormonal, radiological, cardiac, genetic, and functioning evaluation in most cases. A proper preoperative evaluation in combination with strict blood pressure and heart rate control, and blood volume status optimization, will significantly reduce the risk of intraoperative and perioperative complications. In those patients who unfortunately develop intraoperative complications, the role of the anesthesiologist is essential since the selection of the appropriate management has a direct impact on morbimortality reduction.

Hypertensive crisis precatheter ablation for resistant atrial fibrillation: a case of undiagnosed bilateral pheochromocytomas

A 63-year-old man with hypertension was referred for catheter ablation of persistent atrial fibrillation. He was diagnosed with paroxysmal atrial fibrillation approximately 6 years prior. Over the previous 12 months, his atrial fibrillation had become persistent despite medication optimisation for rate control and elective cardioversion. Sinus rhythm was restored briefly. The decision was made to pursue catheter ablation and isolation of the pulmonary veins. On anaesthetic induction, the patient suffered from a hypertensive crisis. The procedure was aborted, and the patient was admitted to hospital for investigations of secondary hypertension. Ultimately, the patient was diagnosed with bilateral pheochromocytomas. This case outlines the diagnostic challenges and cardiac comorbidities associated with bilateral pheochromocytomas.

New aspects of endocrine control of atrial fibrillation and possibilities for clinical translation

Hormones are potent endo-, para-, and autocrine endogenous regulators of the function of multiple organs, including the heart. Endocrine dysfunction promotes a number of cardiovascular diseases, including atrial fibrillation (AF). While the heart is a target for endocrine regulation, it is also an active endocrine organ itself, secreting a number of important bioactive hormones that convey significant endocrine effects, but also through para-/autocrine actions, actively participate in cardiac self-regulation. The hormones regulating heart-function work in concert to support myocardial performance. AF is a serious clinical problem associated with increased morbidity and mortality, mainly due to stroke and heart failure. Current therapies for AF remain inadequate. AF is characterized by altered atrial function and structure, including electrical and profibrotic remodelling in the atria and ventricles, which facilitates AF progression and hampers its treatment. Although features of this remodelling are well-established and its mechanisms are partly understood, important pathways pertinent to AF arrhythmogenesis are still unidentified. The discovery of these missing pathways has the potential to lead to therapeutic breakthroughs. Endocrine dysfunction is well-recognized to lead to AF. In this review, we discuss endocrine and cardiocrine signalling systems that directly, or as a consequence of an underlying cardiac pathology, contribute to AF pathogenesis. More specifically, we consider the roles of products from the hypothalamic-pituitary axis, the adrenal glands, adipose tissue, the renin–angiotensin system, atrial cardiomyocytes, and the thyroid gland in controlling atrial electrical and structural properties. The influence of endocrine/paracrine dysfunction on AF risk and mechanisms is evaluated and discussed. We focus on the most recent findings and reflect on the potential of translating them into clinical application.

Case Report: Pheochromocytoma in a 59-Year-Old Woman Presenting With Hypotension

Background: Pheochromocytoma patients who present with shock are extremely rare. Here, we report a patient who presented with shock and was diagnosed with pheochromocytoma. Case Summary: A 59-year-old woman with a history of hypertension without any treatment for 5 years presented with chest tightness. Vital signs on arrival indicated blood pressure of 78/50 mmHg. Twelve-lead electrocardiogram indicated ST-segment depression in leads II, III, aVF, and V3-V6 and QT prolongation. Coronary angiogram revealed no evidence of coronary artery disease. Contrast-enhanced computed tomography demonstrated an inhomogeneous right adrenal mass (2.5 × 3.0 cm). Her 24-h urinary norepinephrine and catecholamine levels were elevated. The patient underwent laparoscopic right adrenalectomy. Histopathology confirmed adrenal pheochromocytoma with residual necrosis. The patient was diagnosed with pheochromocytoma. During the 2-year follow-up, the patient was asymptomatic, and her blood pressure remained normal without medication. ECG showed that the ST-segment depression in leads II, III, aVF, and V3-V6 and the QT prolongation had disappeared. The patient showed no signs of recurrence, with normal urine norepinephrine and catecholamine levels. Conclusion: Patients with pheochromocytoma can present with hypotension or even shock. Clinicians should suspect pheochromocytoma when a patient with a history of hypertension has sudden hypotension or even shock.

A unique cardiovascular presentation of pheochromocytoma

We describe a unique presentation of a pheochromocytoma in a normotensive teenager, who presented with symptoms of headache, neck pain, and palpitations. Holter and event monitor tracings revealed intermittent junctional rhythm causing electromechanical dyssynchrony between atrial and ventricular contraction resulting in reported symptoms. Exercise stress testing helped correlate symptomatic junctional rhythm events to episodic hypertension which led to the eventual diagnosis of pheochromocytoma. The exercise test provided insight into the physiologic coupling that the sympathetic and parasympathetic autonomic nervous systems have on the cardiovascular system during exercise and exaggerated hypertension. The patient was found to have MEN2A and partial adrenalectomy resulted in complete resolution of symptoms and arrhythmia. This unusual presentation illustrates the benefit of a comprehensive clinical evaluation, which led to the eventual diagnosis.

Catecholamine physiology and its implications in patients with COVID-19

The risk factors for severe COVID-19 are diverse, yet closely resemble the clinical manifestations of catecholamine excess states (eg, hypertension, cardiovascular disease, immune dysregulation, and hyperglycaemia), suggesting a potentially common basis for disease. Unfortunately, severe illness (eg, respiratory failure, compromised cardiac function, and shock) incurred by COVID-19 hinders the direct study of catecholamines in these patients, especially among those on multiple medications or those on adrenaline or noradrenaline infusions, or both. Phaeochromocytoma and paraganglioma (PPGL) are tumours that secrete catecholamines, namely adrenaline and noradrenaline, often in excess. PPGL are well studied disease processes in which the effects of catecholamines are easily discernible and therefore their potential biochemical and physiological influences in patients with COVID-19 can be explored. Because catecholamines are expected to have a role in patients with critical illness, patients on vasopressor infusions, and patients who sustain some acute and chronic physical stresses, the challenges involved in the management of catecholamine excess states are directly relevant to the treatment of patients with COVID-19. In this Personal View, we discuss the complex interplay between catecholamines and COVID-19, and the management of catecholamine excess states, while referencing relevant insights derived from the study of PPGL.