A systematic review on the genetic analysis of paragangliomas: primarily focused on head and neck paragangliomas.

Head and neck paragangliomas Paragangliomas and pheochromocytomas are rare, mostly benign neuroendocrine tumors, which are embryologically derived from neural crest cells of the autonomic nervous system. Paragangliomas are essentially the extra-adrenal counterparts of pheochromocytomas. As such this family of tumors can be subdivided into head and neck paragangliomas, pheochromocytomas and thoracic and abdominal extra-adrenal paragangliomas. Ten out of fifteen genes that contribute to the development of paragangliomas are more susceptible to the development of head and neck paragangliomas when mutated. Gene expression profiling revealed that pheochromocytomas and paragangliomas can be classified into two main clusters (C1 and C2) based on transcriptomes. These groups were defined according to their mutational status and as such strongly associated with specific tumorigenic pathways. The influence of the main genetic drivers on the somatic molecular phenotype was shown by DNA methylation and miRNA profiling. Certain subunits of succinate dehydrogenase (SDHx), von Hippel-Lindau (VHL) and transmembrane protein 127 (TMEM127) still have the highest impact on development of head and neck paragangliomas. The link between RAS proteins and the formation of pheochromocytoma and paragangliomas is clear due to the effect of receptor tyrosine-protein kinase (RET) and neurofibromatosis type 1 (NF1) in RAS signaling and recent discovery of the role of HRAS. The functions of MYC-associated factor X (MAX) and prolyl hydroxylase 2 (PHD2) mutations in the contribution to the pathogenesis of paragangliomas still remain unclear. Ongoing studies give us insight into the incidence of germline and somatic mutations, thus offering guidelines to early detection. Furthermore, these also show the risk of mistakenly assuming sporadic cases in the absence of definitive family history in head and neck paragangliomas.

The effect of adrenalectomy on exercise response of the renin-angiotensin-aldosterone system and exercise tolerance in primary aldosteronism.

Primary aldosteronism (PA) is associated with objectively measured lower physical fitness and blunted response of the renin-angiotensin-aldosterone system to exercise. The purpose of this pilot study was to objectively measure exercise response of the renin-angiotensin-aldosterone system and cardiopulmonary fitness changes after laparoscopic adrenalectomy (ADE) in patients with unilateral PA. We examined a total of 14 patients with confirmed PA before and after ADE, by means of spiroergometry and hormonal evaluation. As expected, after adrenalectomy basal aldosterone (Aldo) levels before exercise decreased significantly, with a concomitant increase in plasma renin (PR). The increase in Aldo (285.9+/-171.3 to 434.1+/-278.2 ng/l; p=0.02) and blunted increase in PR (7.1+/-0.4 to 8.9+/-10.4 pg/ml; NS) post-exercise before ADE became significant after ADE Aldo post-ADE (46.8+/-18.8 to 106.5+/-68.1 ng/l; p<0.0001) and PR post-ADE (20.1+/-14.5 to 33.9+/-30.7 pg/ml; p=0.014). After adrenalectomy, the patients had a non-significant increase in peak workload and VO(2peak). We found normalization of the renin-angiotensin-aldosterone system response to exercise with little changes in cardiopulmonary fitness six months after ADE.

Radioimmunoassay of chromogranin A and free metanephrines in diagnosis of pheochromocytoma.

This work discusses the clinical performance of chromogranin A, free metanephrine and normetanephrine determination in plasma using a radioimmunoanalytical methods for the diagnosis of pheochromocytoma and paraganglioma. Blood samples were collected from 55 patients (46 pheochromocytomas, 9 paragangliomas). A sampling of biological materials was performed preoperatively and about one week, six months and one year after adrenal gland surgery. The comparative group without a diagnosis of pheochromocytoma/paraganglioma consisted of 36 pheochromocytoma/paraganglioma patients more than 4 months after adrenal gland surgery, and of 87 patients, 16 of them with multiple endocrine neoplasia, 9 with medullary and 5 with parafolicullar carcinoma of the thyroid gland. The rest were patients with various adrenal gland disorders. Chromogranin A, metanephrine and normetanephrine were determined in the EDTA-plasma using a radioimmunoassay kits Cisbio Bioassays, France and IBL International GmbH, Germany. Clinical sensitivity was 96 % for the combination of metanephrine and normetanephrine, and 93 % for chromogranin A. Clinical specificity was 100 % for the combination metanephrine and normetanephrine, and 96 % for chromogranin A. Falsely elevated levels of chromogranin A were observed in 1 patient with chronic renal insufficiency and 9 analyses were influenced by the administration of proton pump inhibitors. These results were excluded of CGA specificity. Both the combination of plasma free metanephrine, normetanephrine and chromogranin A as determined by radioimmunoassays, which are simple without the necessity of special laboratory material, are effective markers of pheochromocytoma or paraganglioma. Chromogranin A exerts association to malignity and all markers are associated with tumor mass.

Absence of BRAF mutation in pheochromocytoma and paraganglioma.

Pheochromocytomas and Paragangliomas (PHEO/PARA) are rare endocrine tumors originating from the adrenal medulla. More than 20 genes are involved in the tumorigenesis of these tumors, but a substantial part of the causative genetic events remains unexplained. A recent study has reported the presence of the activating BRAF V600E mutation in PCC, suggesting a role for BRAF activation in tumor development. Other studies have not find this mutation. This study investigates the occurrence of the BRAF V600E mutation in these tumors.A cohort of 64 PHEO/PARA were screened for the BRAF V600E mutation using direct Sanger sequencing and QRT-PCR.All cases investigated displayed wild-type without V600E BRAF mutationTaken together with all previously screened tumors up to date, only 1 V600E BRAF mutation has been found among 427 PCCs. These findings imply that the V600E BRAF mutation is a rare event in PHEO/PARA.

Lower physical fitness in patients with primary aldosteronism is linked to the severity of hypertension and kalemia.

Hypokalemia as a typical feature of primary aldosteronism (PA) is associated with muscle weakness and could contribute to lower cardiopulmonary fitness. The aim of this study was to describe cardiopulmonary fitness and exercise blood pressure and their determinants during a symptom-limited exercise stress test in patients with PA. We performed a cross-sectional study of patients with confirmed PA who were included before adrenal vein sampling on whom a symptom-limited exercise stress test with expired gas analysis was performed. Patients were switched to the treatment with doxazosin and verapamil at least two weeks before the study. In 27 patients (17 male) the VO(2peak) was 25.4+/-6.0 ml/kg/min which corresponds to 80.8+/-18.9 % of Czech national norm. Linear regression analysis shows that VO(2peak) depends on doxazosin dose (DX) (p=0.001) and kalemia (p=0.02): VO(2peak) = 4.2 - 1.0 * DX + 7.6 * Kalemia. Patients with higher doxazosin doses had a longer history of hypertension and had used more antihypertensives before examination, thus indicating that VO(2peak) also depends on the severity of hypertension. In patients with PA, lower cardiopulmonary fitness depends inversely on the severity of hypertension and on lower plasma potassium level.

Inflammatory markers in primary aldosteronism.

Primary aldosteronism (PA) is the most common cause of endocrine hypertension with a high frequency of cardiovascular complications. The unfavorable cardiometabolic profile may be due to aldosterone-mediated activation of inflammatory cells, circulatory cytokines and activation of collagen synthesis in the vessel wall. Aim of our study was to evaluate differences in the levels of hsCRP, IL-6, TNF-alpha and N-terminal propeptide of collagen I (PINP) in patients with PA and essential hypertension (EH) as a control group, and between the subtypes of PA (aldosterone producing adenoma - APA, idiopathic hyperaldosteronism - IHA). We studied 28 patients with PA (IHA - 10 patients, APA - 12 patients, 6 unclassified) and 28 matched patients with EH. There were no differences in the levels of inflammatory markers between the followed groups [EH vs. PA: TNF-alpha (5.09 [3.68-6.32] vs. 4.84 [3.62-6.50] pg/ml), IL-6 (0.94 [0.70-1.13] vs. 0.97 [0.71-1.28] pg/ml), hsCRP (0.53 [0.25-1.54] vs. 0.37 [0.31-0.61] mg/l), leukocytes (6.35+/-1.42 vs. 5.97+/-1.29 10(9) l); APA vs. IHA: TNF-alpha (4.54 [3.62-7.03] vs. 5.19 [4.23-5.27] pg/ml), IL-6 (0.96 [0.63-1.21] vs. 0.90 [0.65-1.06] pg/ml), hsCRP (0.34 [0.29-0.47] vs. 0.75 [0.36-1.11] mg/l), leukocytes (6.37+/-1.41 vs. 5.71+/-1.21 10(9) l)]. Significant differences in the levels of PINP between PA and EH group were observed (35.18 [28.46-41.16] vs. 45.21 [36.95-62.81] microg/l, p

Combination antihypertensive therapy in clinical practice. The analysis of 1254 consecutive patients with uncontrolled hypertension.

The aim of the study was to analyze the clinical use of different types of combination therapy in a large sample of consecutive patients with uncontrolled hypertension referred to Hypertension Centre. We performed a retrospective analysis of combination antihypertensive therapy in 1254 consecutive patients with uncontrolled hypertension receiving at least triple-combination antihypertensive therapy. Among the most prescribed antihypertensive classes were renin-angiotensin blockers (96.8%), calcium channel blockers (82.5%), diuretics (82.0%), beta-blockers (73.0%), centrally acting drugs (56.0%) and urapidil (24.1%). Least prescribed were spironolactone (22.2%) and alpha-1-blockers (17.1%). Thiazide/thiazide-like diuretics were underdosed in more than two-thirds of patients. Furosemide was prescribed in 14.3% of patients treated with diuretics, while only indicated in 3.9%. Inappropriate combination therapy was found in 40.4% of patients. Controversial dual and higher blockade of renin-angiotensin system occurred in 25.2%. Incorrect use of a combination of two antihypertensive drugs with the similar mechanism of action was found in 28.1%, most commonly a combination of two drugs with central mechanism (13.5%). In conclusion, use of controversial or incorrect combinations of drugs in uncontrolled hypertension is common. Diuretics are frequently underdosed and spironolactone remains neglected in general practice. The improper combination of antihypertensive drugs may contribute to uncontrolled hypertension.

Deconjugated urinary metanephrine, normetanephrine and 3-methoxytyramine in laboratory diagnosis of pheochromocytoma and paraganglioma.

This work discusses the clinical performance of deconjugated metanephrine (MN), normetanephrine (NMN) and 3-methoxytyramine (3MT) determined in the basal first morning urine using a chromatographic method with electrochemical detection for the clinical diagnosis of pheochromocytoma (PHEO) and paraganglioma (PGL). Urine samples were collected from 44 patients (36 with PHEO, 8 with PGL) aged 54+/-17 (20-78) years (22 females, 22 males). A sampling of biological materials was performed preoperatively and about one week, six months and one year after adrenal gland surgery. The control group consisted of 34 PHEO/PGL patients more than 4 months after adrenal gland surgery. All subjects in the control group were without a diagnosis of PHEO or PGL. Clinical sensitivity was 55 % for MN, 64 % for NMN, 80 % for combination of both MN and NMN, and only 23 % for 3TM. Clinical specificity calculated from the control group was 93 % for MN, 95 % for NMN, 95 % for the combination MN and NMN, and 97 % for 3TM. Cut-off values for deconjugated metanephrines in the basal urine were 310 (MN), 690 (NMN) and 250 microg/l (3MT). Chromatographic determination of deconjugated urinary metanephrines, which is simple without the necessity of special laboratory material, can serve for the screening of PHEO or PGL patients. Urine NMN and 3MT exerts an association to malignity, and all markers are associated with tumor mass. However, the principal laboratory diagnosis of PHEO or PGL must be based on plasma-free metanephrines and plasma chromogranin A with better performance in the laboratory diagnosis of PHEO or PGL.

Biochemical Testing After Pheochromocytoma Removal: How Early?

Pheochromocytomas are catecholamine-producing tumors with typical clinical presentation. Tumor resection is considered as an appropriate treatment strategy. Due to its unpredictable clinical behavior, biochemical testing is mandatory to confirm the success of tumor removal after surgery. The aim of the study was to investigate the feasibility of a shorter interval of postoperative testing (earlier than the recommended 2-4 weeks according to recently published Guidelines). We investigated 81 patients with pheochromocytoma before and after surgery. Postoperative examination was performed of stable subjects after their transport from the surgical to the internal ward (7.1±2.2 days after surgery). Plasma metanephrines were used for the diagnosis of pheochromocytoma and confirmation of successful tumor removal. All subjects with pheochromocytoma had markedly elevated plasma metanephrines before surgery. No correlation between postoperative interval (the shortest being 3 days) and plasma metanephrine levels was found. Postoperative plasma metanephrine levels did not differ significantly from those taken at the one-year follow-up. In conclusion, we have shown that early postoperative diagnostic workup of subjects with pheochromocytoma is possible and may thus simplify early postoperative management of this clinical condition.

HIF signaling pathway in pheochromocytoma and other neuroendocrine tumors.

Hypoxia-inducible factors (HIFs) are transcription factors controlling energy, iron metabolism, erythropoiesis, and development. Dysregulation of these proteins contributes to tumorigenesis and cancer progression. Recent findings revealed the important role of HIFs in the pathogenesis of neuroendocrine tumors, especially pheochromocytoma (PHEO) and paraganglioma (PGL). PHEOs and PGLs are catecholamine-producing tumors arising from sympathetic- or parasympathetic-derived chromaffin tissue. To date, eighteen PHEO/PGL susceptibility genes have been identified. Based on the main signaling pathways, PHEOs/PGLs have been divided into two clusters, pseudohypoxic cluster 1 and cluster 2, rich in kinase receptor signaling and protein translation pathways. Recent data suggest that both clusters are interconnected via the HIF signaling and its role in tumorigenesis is supported by newly described somatic and germline mutations in HIF2A gene in patients with PHEOs/PGLs associated with polycythemia, and in some of them also with somatostatinoma. Moreover, HIFalpha signaling has also been shown to be upregulated in neuroendocrine tumors other than PHEO/PGL. Some of these tumors are components of hereditary tumor syndromes which can be associated with PHEO/PGL, but also in ileal carcinoids or melanoma. HIF signaling appears to be one of the crucial players in tumorigenesis, which could suggest new therapeutic approaches for treatment of neuroendocrine tumors.

Three months of regular aerobic exercise in patients with obesity improve systemic subclinical inflammation without major influence on blood pressure and endocrine production of subcutaneous fat.

The aim of our study was to explore the effects of regular aerobic exercise on anthropometric, biochemical and hormonal parameters and mRNA expression of selected factors involved in metabolic regulations in subcutaneous adipose tissue of patients with obesity. Fifteen obese women with arterial hypertension underwent a three-month exercise program consisting of 30 min of aerobic exercise 3 times a week. Fifteen healthy lean women with no intervention served as a control group. Obese group underwent anthropometric measurements, blood sampling, subcutaneous adipose tissue (SCAT) biopsy and 24-h blood pressure monitoring at baseline and after three months of exercise, while control group was examined only once. At baseline, obese group had increased SCAT expression of proinflammatory cytokines and adipokines relative to control group. Three months of regular exercise improved anthropometric parameters, decreased CRP, blood glucose and HOMA-IR, while having no significant effect on lipid profile and blood pressure. Gene expressions in SCAT were not affected by physical activity with the exception of increased aquaporin-3 mRNA expression. We conclude that three months of regular exercise decrease systemic subclinical inflammation with only minor influence on the blood pressure and the endocrine function of subcutaneous fat.

Importance of thorough investigation of resistant hypertension before renal denervation: should compliance to treatment be evaluated systematically?

Catheter-based renal denervation (RD) has been introduced recently as a potentially effective invasive treatment of refractory hypertension. The proportion of patients with severe hypertension suitable for RD is not clear. The aim of this study was to identify what percentage of patients has truly resistant essential hypertension and are thus potentially eligible for RD. We investigated 205 consecutive patients referred to a university hypertension center for severe hypertension within 12 months. Ambulatory 24-h blood pressure (BP) monitoring (24 h ABPM), secondary hypertension screening and compliance to treatment testing (by use of plasma drug level measurements) were performed in all patients. Fifty-seven patients (27.8%) did not have truly resistant hypertension (RH) based on clinical BP. Among the remaining 122 patients (59.5%) with RH confirmed by 24 h ABPM, 50 patients (24.4% of the original cohort) had a secondary cause of hypertension and in 27 (13.2%) non-compliance to treatment was confirmed. Thus, only 45 patients (22%) had truly resistant essential hypertension and were considered for RD. Only one-third (n=15, 7.3% of the original cohort) was, however, finally referred for RD (14 were excluded due to contraindications for RD and 16 refused the invasive treatment). In conclusion, thorough examination of severe hypertension including 24 h ABPM, secondary hypertension exclusion and drug compliance testing before considering RD reveals that majority of these patients are not suitable for RD. Specifically, compliance to treatment testing should be mandatory in order to identify eligible candidates for RD.

Pheochromocytoma and markers of oxidative stress.

High levels of catecholamines in pheochromocytoma (PHEO) are associated with risk of cardiovascular complications. In this study, we looked for potential differences in markers of oxidative stress - vitamin C, superoxide dismutase (SOD) and malondialdehyde (MDA) in PHEO before and after the operation. We studied 18 subjects with PHEO who were examined before and approximately one year after the successful tumor removal (free of disease). All subjects had elevated urinary epinephrine and/or norepinephrine levels before the operation. Vitamin C levels increased significantly after the operation from 61+/-27 to 77+/-20 micromol/l (P=0.02), and MDA decreased significantly after the tumor removal from 2.6+/-0.4 to 2.0+/-0.6 micromol/l (P=0.01). However, no changes were found in SOD activity before and after the operation. In conclusion, increased catecholamine production in PHEO is accompanied by decreased levels of vitamin C and increased levels of MDA which may indicate the activation of oxidative stress in PHEO. Successful operation was associated with lowering of oxidative stress by using both biomarkers. On the contrary, no changes in SOD activity before and after the tumor removal were noted.

Changes in energy metabolism in pheochromocytoma.

CONTEXT: Catecholamine overproduction in pheochromocytoma affects basal metabolism, resulting in weight loss despite normal food intake. OBJECTIVE: The objective of the study was to evaluate changes in energy metabolism expressed as resting energy expenditure (REE) in patients with pheochromocytoma before and after adrenalectomy and the possible relationship with circulating inflammatory markers. DESIGN: We measured REE in 17 patients (8 women) with pheochromocytoma by indirect calorimetry (Vmax-Encore 29N system) before and 1 year after adrenalectomy. Body fat percentage was measured with a Bodystat device. Inflammatory markers (leukocytes count and C-reactive protein) and cytokines (TNF-α, IL-6, and IL-8) were analyzed with a Luminex 200. RESULTS: REE measured in the pheochromocytoma group was 10.4% higher than the predicted value (1731 ± 314 vs 1581 ± 271 kcal/d; P = .004). Adrenalectomy significantly increased body mass index (P =0.004) and the percentage of body fat (P = .01), with a proportional increase in fat distribution (waist circumference, P = .045; hip circumference, P = .001). REE significantly decreased after adrenalectomy (1731 ± 314 vs 1539 ± 215 kcal/d; P = .002), even after adjustments in body surface and body weight (P < .001). After adrenalectomy, we found a significant decrease in leukocyte counts (P = .014) and in the levels of TNF-α (P < .001), IL-6 (P = .048), and IL-8 (P = .007) but not C-reactive protein (P = .09). No significant correlations among calorimetry parameters, hormones, and proinflammatory markers were detected. CONCLUSIONS: Chronic catecholamine overproduction in pheochromocytoma may lead to a proinflammatory and hypermetabolic state characterized by increased REE. Adrenalectomy leads to the normalization of energy metabolism followed by an increase in body mass index and body fat content and decreases in inflammatory markers and cytokines.

Vascular disturbances in primary aldosteronism: clinical evidence.

Primary aldosteronism (PA) is a common form of arterial hypertension with a high prevalence of cardiovascular complications. In patients with PA, complex mechanisms may lead to functional and/or structural abnormalities of the blood vessel wall. Clinical evidence indicates that patients with PA may have immune cell activation, increased oxidative stress, impaired endothelial function and vascular remodeling. Activation of fibroproliferation has been found in resistant arteries of patients with PA. Subjects with PA compared to essential hypertensives with similar blood pressure levels have increased intima-media thickness and arterial stiffness as measured by pulse wave velocity. These functional and morphological changes can be modified by an increased sodium intake. Vascular remodeling in PA may indicate a poor response to specific therapy with lower probability of cure and/or normalization of blood pressure. Early diagnosis of PA before blood vessel wall disturbances develop is of utmost importance.

[Hereditary pheochromocytoma and paraganglioma]. / Hereditární feochromocytom a paragangliom.

Pheochromocytomas and paragangliomas are tumors arising from chromaffin cells. These tumors produce catecholamines and are typically found with symptoms and signs that may include hypertension (persistent or episodic), palpitations, headache and sweating. So far, 10 different genes have been associated with both tumors and other genes are expected to be detected. Pheochromocytoma and paraganglioma can occur as a part of genetic syndromes - familial paragangliomas (SDH genes, SDHAF2 gene), von Hippel-Lindau syndrome (VHL gene), multiple endocrine neoplasia type 2 (RET gene), and neurofibromatosis type 1 (NF1 gene). These tumors may be the first and only manifestation of these genetic syndromes. Patients with SDHB mutations are at high risk to develop malignant disease and unfortunately current therapeutic options for malignant form of disease are poor. Genetic testing plays a key role in the management of these tumors and therefore not only index patients with pheochromocytoma but also relatives should be tested. Management of this disease requires multidisciplinary cooperation and should be performed in the specialized medical centres.

Peripheral arterial stiffness in primary aldosteronism.

Aldosterone overproduction increases arterial wall stiffness by accumulation of different types of collagen fibres and growth factors. Our previous studies showed that central (aortic) arterial stiffness is increased in primary aldosteronism (PA) independently of concomitant hypertension and that these changes might be reversible after successful adrenalectomy. There is limited data available on the potential impact of mineralocorticoid overproduction on the deterioration of peripheral arterial stiffness. The current study was thus aimed at investigating the effect of aldosterone overproduction on peripheral arterial stiffness assessed by peripheral (femoral-ankle) pulse wave velocity (PWV) in PA patients compared with essential hypertension (EH) patients. Forty-nine patients with confirmed PA and 49 patients with EH were matched for age, blood pressure, body mass index, lipid profile, and fasting glucose. PWV was obtained using the Sphygmocor applanation tonometer. Both peripheral and central PWV were significantly higher in PA patients compared to EH patients, while clinical blood pressures were similar. Plasma aldosterone level was the main predictor of peripheral PWV in PA. Our data indicate aldosterone overproduction in PA does not preferentially affect central arterial system. Fibroproliferative effect of higher aldosterone levels lead to alteration of central-elastic as well as peripheral-muscular arteries with subsequent increase in its stiffness.

Have main types of primary aldosteronism different phenotype?

Primary aldosteronism (PA) is the most common cause of endocrine hypertension with a high frequency of cardiovascular complications. We found in our previous study higher occurrence of metabolic disturbances in patients with idiopathic hyperaldosteronism (IHA) compared to subjects with aldosterone-producing adenoma (APA). The aim of our present study is to evaluate potential differences in the frequency of end-organ damage (arterial stiffness and microalbuminuria) between two main types of PA. The diagnosis of the particular form of PA was based on adrenal venous sampling and/or histopathological examination. We analyzed clinical and laboratory data from 72 patients with PA (36 with IHA, 36 with APA). The arterial stiffness was expressed as the carotid-femoral pulse wave velocity (PWV) and the renal damage as urinary albumin excretion levels (UAE). Patients with IHA had significantly (p<0.03) higher prevalence of metabolic syndrome (17 % in APA, 35 % in IHA), higher triglycerides (1.37+/-0.71 mmol/l in APA, 1.85+/-0.87 mmol/l in IHA), lower HDL cholesterol (1.25+/-0.28 mmol/l in APA, 1.06+/-0.25 mmol/l in IHA), higher PWV (7.91+/-1.61 m/s in APA, 8.99+/-1.77 m/s in IHA) and higher UAE (12.93+/-2.21 mg/l in APA, 28.09+/-6.66 mg/l in IHA). It seems that patients with IHA may have a slightly different phenotype compared to APA.

High incidence of cardiovascular complications in pheochromocytoma.

Excess of catecholamines in pheochromocytoma is usually accompanied with classical symptoms and signs. In some cases, severe cardiovascular complications (e. g., heart failure, myocardial infarction) may occur. We performed a retrospective analysis focused on the incidence of cardiovascular complications (classified as follows: arrhythmias, myocardial involvement or ischemia and atherosclerosis, cerebrovascular impairment) before the establishment of diagnosis of pheochromocytoma among 145 subjects treated in our hospital. Cardiovascular complications occurred in 28 subjects, but these subjects did not differ significantly from subjects without complications in age, gender, body mass index, paroxysmal symptoms, symptom duration, tumor dimension, catecholamine secretory phenotype, and incidence of hypertension or diabetes mellitus. Arrhythmias occurred in 15 subjects (2 arrhythmia types in 2 subjects): atrial fibrillation in 9 subjects, supraventricular tachycardia in 3 cases, and ventricular tachycardia in 2 patients. Significant bradycardia was noted in 3 cases. Five subjects presented with heart failure with decreased systolic function (takotsubo-like cardiomyopathy found in 2 cases). One subject suffered from hypertrophic obstructive cardiomyopathy. Seven subjects presented with non-ST-segment elevation myocardial infarction, 2 patients with ST-segment myocardial infarction, and 1 subject underwent coronary artery bypass grafting. Two subjects suffered from significant peripheral atherosclerosis. Among cerebrovascular complications, transient ischemic attack was found in 3 cases, 2 subjects suffered from stroke, and subarachnoidal bleeding occurred in 1 patient. One subject suffered from diffuse neurological impairment due to multiple ischemic white matter lesions. These data show relatively high incidence of cardiovascular complications (19.3%) in subjects with pheochromocytoma. Early diagnosis is mandatory to prevent severe complications in pheochromocytoma.

[Diagnostic of secondary hypertension in clinical practice]. / Diagnostika sekundární hypertenze v ambulantní praxi.

Arterial hypertension is a common worldwide disease with a prevalence of approximately 26%. Secondary cause is known in 5-10% of patients with hypertension. We should think of secondary hypertension in all patients with resistant hypertension, in patients with sudden deterioration in the control of hypertension and in patients with laboratory and clinical signs of diseases associated with secondary hypertension. It is important to distinguish between secondary hypertension and pseudo-resistance (noncompliance to treatment, white coat syndrome). Secondary causes of hypertension can be divided into endocrine (primary aldosteronism, pheochromocytoma, hypercortisolism, hyperparathyreoidism), renal - renovascular and renal parenchymal hypertension, and other causes as sleep apnoe syndrome, hypertension in pregnancy, coarctation of the aorta and intracranial tumors.