Safety of cryoballoon ablation for the treatment of atrial fibrillation: First European results from the cryo AF Global Registry.

BACKGROUND: Cryoballoon ablation for the treatment of patients with atrial fibrillation (AF) has been utilized in Europe for >15 years. OBJECTIVES: Report patient and procedural characteristics that influence the safety of cryoablation for the treatment of AF. METHODS: Patients enrolled in the prospective, multicenter Cryo AF Global Registry were treated at 38 European centers. Freedom from a ≥30s episode of AF/atrial flutter (AFL)/atrial tachycardia (AT) at 12-months and serious complications were analyzed. Univariate and multivariable models identified baseline patient and procedural characteristics that predicted a procedure-related complication. RESULTS: Of the 1418 subjects who completed an index procedure, the cohort was 62 ± 11 years of age, 37.7% female, and 72.2% paroxysmal AF (PAF). The mean procedure, left atrial dwell, and fluoroscopy times were 81 ± 34, 54 ± 25, and 14 ± 13 min, respectively. Among the 766 patients with 12-month follow-up, freedom from a ≥30 s AF/AFL/AT recurrence was 83.3% (95% CI: 79.8%-86.3%) and 71.6% (95% CI: 64.6%-77.4%) in patients with PAF and persistent AF. The serious procedure- and device-related adverse event rates were 4.7% and 2.0%. No baseline patient characteristic independently predicted a procedure-related adverse event; however, prolonged procedure duration (OR = 1.01 [95% CI: 1.00-1.01]), use of general anesthesia (OR = 1.71 [95% CI: 1.01-2.92]), and delivery of a cavotricuspid isthmus line (OR = 3.04 [95% CI: 1.01-9.20]) were each independently associated with the occurrence of a serious procedural safety event (all p < .05). CONCLUSIONS: Cryoballoon ablation is safe and effective in real-world use across a broad cohort of patients with AF.

Diagnosis and management of left atrial appendage thrombus in patients with atrial fibrillation undergoing cardioversion or percutaneous left atrial procedures: results of the European Heart Rhythm Association survey.

Practices regarding indications and timing for transoesophageal echocardiography (TOE) before cardioversion (CV) of atrial fibrillation (AF) or left atrial (LA) interventional procedures, and preferred imaging techniques and pharmacotherapy, in cases of thrombus resistant to chronic oral anticoagulation (OAC) treatment, are largely unknown. The European Heart Rhythm Association (EHRA) conducted a survey to capture contemporary clinical practice in those areas of AF care. A 22-item online questionnaire was developed and distributed among the EHRA electrophysiology research network centres. The survey contained questions regarding indications, type and timing of imaging before CV or LA procedures and management of LA appendage (LAA) thrombus with special emphasis on thrombus resistant to OAC. Of 54 responding centres 63% were university hospitals. Most commonly, TOE would be performed in cases of inadequate or unclear pre-procedural anticoagulation, even in AF lasting <48 h (52% and 50%, respectively), and 15% of centres would perform TOE before AF ablation in all patients. If thrombus was diagnosed despite chronic OAC, the prevalent strategy was to change current OAC to another with different mechanism of action; 51% of centres would wait 3-4 weeks after changing the OAC before using another imaging test, and 60% of centres reported two attempts to dissolve the thrombus. Our survey showed a significant utilization of TOE before CV or AF ablation in European centres, extending beyond AF guidelines-suggested indications. When thrombus was diagnosed despite chronic pre-procedural OAC, most centres would use another anticoagulant drug with different mode of action.

Baseline intrinsic heart rate and response to ivabradine treatment in patients with inappropriate sinus tachycardia.

BACKGROUND: Treatment with ivabradine became a new therapeutic alternative for patients with inappropriate sinus tachycardia (IST). The aim was to determine a relation between intrinsic heart rate (IHR) and response to ivabradine treatment. METHODS: Twenty-seven patients (mean age 37 ± 11; 23 women) with symptomatic IST despite medical treatment were recruited into the study. Resting ECG, 24-hr ECG monitoring (24hECG), exercise treadmill test, and symptoms evaluation were performed initially and after 60 days on ivabradine. IHR was acquired at baseline after pharmacological autonomic blockade. RESULTS: Nineteen patients (70%) were classified as abnormal IHR group (AIHR) while eight showed normal IHR (NIHR). No significant differences in ECG parameters were found between NIHR and AIHR subgroups, while baseline exercise capacity was higher in AIHR patients (10.9 vs. 9.5 METs, p < .05). Ivabradine treatment resulted in significant reduction in resting heart rate, average 24hECG heart rate, improvement in exercise capacity and reduction of symptoms in both subgroups. Nevertheless, favorable influence of ivabradine was significantly more exaggerated in AIHR subgroup (HR 116 vs. 90 bpm, av. HR 98 vs. 79 bpm, 10.9 vs. 13.6 METS, EHRA score 3.1 vs. 1.1, p < .001 for all) than in NIHR patients (HR 112 vs. 98 bpm, av. HR 97 vs. 88 bpm, 9.5 vs. 11.1 METs, EHRA score 3.1 vs. 1.9; p < .05 for all). CONCLUSIONS: Intrinsic heart rate may be useful in predicting response to ivabradine in patients with IST. More intense response to ivabradine in patients with AIHR may be attributed to different pathophysiological mechanisms underlying IST in AIHR and NIHR groups.

Effect of Renal Denervation and Catheter Ablation vs Catheter Ablation Alone on Atrial Fibrillation Recurrence Among Patients With Paroxysmal Atrial Fibrillation and Hypertension: The ERADICATE-AF Randomized Clinical Trial.

Importance: Renal denervation can reduce cardiac sympathetic activity that may result in an antiarrhythmic effect on atrial fibrillation. Objective: To determine whether renal denervation when added to pulmonary vein isolation enhances long-term antiarrhythmic efficacy. Design, Setting, and Participants: The Evaluate Renal Denervation in Addition to Catheter Ablation to Eliminate Atrial Fibrillation (ERADICATE-AF) trial was an investigator-initiated, multicenter, single-blind, randomized clinical trial conducted at 5 referral centers for catheter ablation of atrial fibrillation in the Russian Federation, Poland, and Germany. A total of 302 patients with hypertension despite taking at least 1 antihypertensive medication, paroxysmal atrial fibrillation, and plans for ablation were enrolled from April 2013 to March 2018. Follow-up concluded in March 2019. Interventions: Patients were randomized to either pulmonary vein isolation alone (n = 148) or pulmonary vein isolation plus renal denervation (n = 154). Complete pulmonary vein isolation to v an end point of elimination of all pulmonary vein potentials; renal denervation using an irrigated-tip ablation catheter delivering radiofrequency energy to discrete sites in a spiral pattern from distal to proximal in both renal arteries. Main Outcomes and Measures: The primary end point was freedom from atrial fibrillation, atrial flutter, or atrial tachycardia at 12 months. Secondary end points included procedural complications within 30 days and blood pressure control at 6 and 12 months. Results: Of the 302 randomized patients (median age, 60 years [interquartile range, 55-65 years]; 182 men [60.3%]), 283 (93.7%) completed the trial. All successfully underwent their assigned procedures. Freedom from atrial fibrillation, flutter, or tachycardia at 12 months was observed in 84 of 148 (56.5%) of those undergoing pulmonary vein isolation alone and in 111 of 154 (72.1%) of those undergoing pulmonary vein isolation plus renal denervation (hazard ratio, 0.57; 95% CI, 0.38 to 0.85; P = .006). Of 5 prespecified secondary end points, 4 are reported and 3 differed between groups. Mean systolic blood pressure from baseline to 12 months decreased from 151 mm Hg to 147 mm Hg in the isolation-only group and from 150 mm Hg to 135 mm Hg in the renal denervation group (between-group difference, -13 mm Hg; 95% CI, -15 to -11 mm Hg; P < .001). Procedural complications occurred in 7 patients (4.7%) in the isolation-only group and 7 (4.5%) of the renal denervation group. Conclusions and Relevance: Among patients with paroxysmal atrial fibrillation and hypertension, renal denervation added to catheter ablation, compared with catheter ablation alone, significantly increased the likelihood of freedom from atrial fibrillation at 12 months. The lack of a formal sham-control renal denervation procedure should be considered in interpreting the results of this trial. Trial Registration: ClinicalTrials.gov Identifier: NCT01873352.

Severe atrial fibrosis as a cause of significant intraatrial conduction delay in a patient with scleromyositis.

Scleromyositis is an autoimmune disease and an overlap syndrome of scleroderma and poly/dermatomyositis. It is characterized by frequent cardiovascular involvement including heart failure, arrhythmias and conduction disturbances. We present a case of a 73-year old female patient who required an upgrade from a DDD pacemaker to cardiac resynchronization therapy due left ventricular dysfunction and permanent ventricular pacing. Electroanatomical mapping (CARTO 3D) revealed extensive right atrial fibrosis which resulted in significant delay in intraatrial conduction. Interval from atrial paced stimulus to A signal in His bundle was 364 ms, while AH and HV intervals were within normal range.

Statement by a Working Group conceived by the Polish National Consultants in Cardiology and Neurology addressing the use of implantable cardiac monitors in patients after ischaemic embolic stroke of undetermined source.

INTRODUCTION: Stroke remains one of the main causes of death and the most common cause of long-term disability in adults. Embolic strokes of undetermined source (ESUS) amount to a significant proportion of all ischaemic strokes. Detection of atrial fibrillation (AF) in this group of patients would allow for a major therapeutic decision to switch from antiplatelets to oral anticoagulants and therefore significantly reduce the risk of recurrence. STATE OF THE ART: Current technology allows long-term continuous ECG monitoring with different systems, including implantable cardiac monitors (ICM). However, in Poland lack of reimbursement does not allow their use in everyday clinical practice. CLINICAL IMPLICATIONS: This is a statement by a Working Group conceived by the Polish National Consultants in Cardiology and Neurology addressing the use of ICM in patients after ischaemic embolic strokes of undetermined source. The aim was to develop reasonable and comprehensive guidance on how to select and manage candidates for ICM in order to obtain the maximum benefit for Polish public health. FUTURE DIRECTIONS: This expert opinion is not intended as a guideline but it provides advice as to how to optimise the potential use of ICM in patients after ESUS in the Polish setting.

Self-terminating ventricular fibrillation recorded by an implantable loop recorder as a cause of syncope - A case report.

Ventricular fibrillation (VF) is the most common arrhythmia leading to sudden cardiac death, but in rare cases VF can manifest as a syncope, provided that it will self-terminate. We present a case of a 45-year old female with a history of unexplained syncopal episodes despite exhaustive diagnostics. Implantable loop recorder documented an episode of idiopathic, self-terminating VF as a cause of syncope.

The clinical value of T-wave alternans derived from Holter monitoring.

Microvolt-level T-wave alternans (TWA) assessed by spectral method during an exercise stress test has been widely studied for risk stratification. Several studies have documented the association of a positive TWA with total mortality and arrhythmic events. Nevertheless, the need to achieve an elevated and stabilized heart rate resulting in a considerable proportion of indeterminate test results constitutes one of the main limitations of this method. It is well recognized that arrhythmic events may be triggered not only by physical but also by mental stress and are not necessarily associated with exercise. Detection of TWA in ambulatory electrocardiogram recordings during daily activities might be a valuable option in risk stratification. This review describes the modified moving average (MMA) technique for detection of TWA and summarizes the results of clinical studies on the prognostic value of MMA-TWA. So far, MMA-TWA has been studied in over 5000 patients including those evaluated during exercise as well as during daily activities with ambulatory ECG recordings. The results of these studies indicate that increased MMA-TWA is associated with higher risk of cardiac mortality and arrhythmic events.

Cryoablation for treatment of cardiac arrhythmias: results of the European Heart Rhythm Association survey.

The purpose of this survey was to assess the current practice in Europe regarding cryoablation for treatment of different cardiac arrhythmias. The data are based on an electronic questionnaire sent to members of the European Heart Rhythm Association Research Network. Responses were received from 49 centres in 18 countries. The results show that cryoablation for supraventricular tachycardia in European centres is an alternative to radiofrequency ablation, which is in accordance with guidelines. There is reasonable consensus regarding clinical results and complications of cryoablation procedure. Some inter-centre variability with respect to patient selection and ablation strategy in cryoablation of atrial fibrillation was demonstrated, underscoring the need for further research.

Potential benefit of optimizing atrioventricular & interventricular delays in patients with cardiac resynchronization therapy.

BACKGROUND & OBJECTIVES: The clinical benefit of optimization (OPT) of atrioventricular delay (AVD) and interventricular delay (VVD) in cardiac resynchronization therapy (CRT) remains debatable. This study was aimed to determine the influence of AVD and VVD OPT on selected parameters in patients early after CRT implantation and at mid-term follow up (FU). METHODS: Fifty two patients (61±10 yr, 23 males) with left bundle branch block, left ventricular ejection fraction (LVEF) ≤35 per cent and heart failure were selected for CRT implantation. Early on the second day (2DFU) after CRT implantation, the patients were assigned to the OPT or the factory setting (FS) group. Haemodynamic and electrical parameters were evaluated at baseline, on 2DFU after CRT and mid-term FU [three-month FU (3MFU)]. Echocardiographic measures were assessed before implantation and at 3MFU. The AVD/VVD was deemed optimal for the highest cardiac output (CO) with impedance cardiography (ICG) monitoring. RESULTS: On 2DFU, the AVD was shorter in the OPT group, LV was paced earlier than in FS group and CO was insignificantly higher in OPT group. At 3MFU, improvement of CO was observed only in OPT patients, but the intergroup difference was not significant. At 3MFU in OPT group, reduction of LV in terms of LV end-diastolic diameter (LVeDD), LV end-systolic diameter, LV end-diastolic and systolic volume with the improvement in LVEF was observed. In FS group, only a reduction in LVeDD was present. In OPT group, the paced QRS duration was shorter than in FS group patients. INTERPRETATION & CONCLUSIONS: CRT OPT of AVD and VVD with ICG was associated with a higher CO and better reverse LV remodelling. CO monitoring with ICG is a simple, non-invasive tool to optimize CRT devices.

Relationship Between Changes in Pulse Pressure and Frequency Domain Components of Heart Rate Variability During Short-Term Left Ventricular Pacing in Patients with Cardiac Resynchronization Therapy.

BACKGROUND The aim of the study was to explore the relationship between changes in pulse pressure (PP) and frequency domain heart rate variability (HRV) components caused by left ventricular pacing in patients with implanted cardiac resynchronization therapy (CRT). MATERIAL AND METHODS Forty patients (mean age 63±8.5 years) with chronic heart failure (CHF) and implanted CRT were enrolled in the study. The simultaneous 5-minute recording of beat-to-beat arterial systolic and diastolic blood pressure (SBP and DBP) by Finometer and standard electrocardiogram with CRT switched off (CRT/0) and left ventricular pacing (CRT/LV) was performed. PP (PP=SBP-DBP) and low- and high-frequency (LF and HF) HRV components were calculated, and the relationship between these parameters was analyzed. RESULTS Short-term CRT/LV in comparison to CRT/0 caused a statistically significant increase in the values of PP (P<0.05), LF (P<0.05), and HF (P<0.05). A statistically significant correlation between ΔPP and ΔHF (R=0.7384, P<0.05) was observed. The ΔHF of 6 ms2 during short-term CRT/LV predicted a PP increase of ≥10% with 84.21% sensitivity and 85.71% specificity. CONCLUSIONS During short-term left ventricular pacing in patients with CRT, a significant correlation between ΔPP and ΔHF was observed. ΔHF ≥6 ms2 may serve as a tool in the selection of a suitable site for placement of a left ventricular lead.

[Technical options of electrotherapy in patients with vasovagal syncope]. / Techniczne mozliwosci elektroterapii u osób z omdleniami wazowagalnymi.

Syncope is a symptom of the disease with diverse etiology and can be evidence of both benign and very serious life-threatening conditions. Vasovagal syncope(VVS), with prevalence about 35% of the general population, is most frequent causes of transient loss of consciousness (T-LOC). Most cases of vasovagal syncope requires conservative treatment. Although cardioinhibitory type of VVS characterized by a significant bradycardia or pause of the heart rate and can be treated with continuous electrotherapy. This article discuss cardiac pacing and technical solutions for the treatment of VVS. Available cardiac pacing methods used to detect and break VVS such as Rate Drop Response (RDR), Closed Loop Stimulation (CLS) and rate response driven by variations of myocardial contractility like Peak Endocardial Acceleration (PEA), has been presented.

[Long-term prognosis in patients with vasovagal syncope after pacemaker implantation]. / Rokowanie odlegle u pacjentów z omdleniami wazowagalnymi po implantacji kardiostymulatora.

Patients with syncope, without presence of a structural or primary electrical disease, have a very good prognosis. On the other hand, recurring syncope has a negative impact on quality of life and involves a real risk of physical injuries. Vasovagal syncope usually requires no medical therapy and the most commonly recommended instruction include avoidance of fainting triggers, exercise that mainly provoke leg muscles tension, increase salt consumption and drink indicated amount of fluids. In the case cardioinhibitory type of vasovagal syncope the pacemaker implantation can consider. Unfortunately, not all patients benefit from this treatment. Medical society clearly highlights that proper qualification of VVS patients is the most important factor for cardiostimulator implantation. This article aims to summarize the most important research and guidelines concerning cardiac pacing for patients with vasovagal syncope.

[Clinical procedure in amiodarone-induced thyroid dysfunction]. / Postepowanie kliniczne w poamiodaronowych zaburzeniach czynnosci gruczolu tarczowego.

Amiodarone is an antiarrhythmic drug frequently used in everyday clinical practice. Its mechanism of action involves the interaction with many receptors, including those in the cardiac conduction system. Amiodarone usefulness is protect in the treatment of a variety of tachyarrhythmias, both benign and life-threatening. In contrast to other antiarrhythmic drugs, amiodarone is characterized by high therapeutic efficacy, both in patients with normal and impaired left ventricular systolic function. A significant limitation of its is associated with side effects including thyroid gland dysfunction. Disturbances of this organ associated with amiodarone are an important diagnostic and therapeutic problem. They may contribute to the occurrence of both Amiodarone- Induced Thyrotoxicosis (AIT) and Amiodarone-Induced Hypothyroidism (AIH). The risk of such complications should be considered for each patient individually, taking into account thyroid function at the beginning of pharmacotherapy. Appropriate procedure, both before and after treatment allows a rapid diagnosis and treatment of thyroid disturbances. It seems that the best parameter used to assess the hormonal imbalance during amiodarone therapy is the concentration of the free triiodothyronine (fT3). The evaluation of thyroid function should be performed before starting pharmacotherapy, and then repeated every six months. In the case of a thyroid dysfunction, assessment must be performed immediately according to standard diagnostic and therapeutic regimens. Despite abnormal thyroid function, high efficiency of amiodarone and relatively small risk of thyroid damage allows continuation therapy. Amiodarone therapy requires a care from both cardiologist and endocrinologist. The aim of this paper is to present the state of art of evaluation of the thyroid function and procedures implemented in care of thyroid dysfunction before and during treatment with amiodarone.

[Atrial fibrillation in patients with heart failure].

The most common arrhythmia is atrial fibrillation, which is very often associated with heart failure. Treatment of both clinical entries are difficult and became a clinical, social and economic challenge in last decades. The authors present clinical aspects connected with a coexistence of HF and AF. They discuss systematic review of research studies regarding medical therapy and invasive electrotherapy.

[Baroreflex sensitivity: measurement and clinical aspects]. / Odruch z baroreceptorów tetniczych: metody oceny i zastosowanie kliniczne.

Homeostasis of blood pressure is indispensable for proper functioning of the body. Sympathetic and parasympathetic part of the autonomic nervous system (ANS), acting on the principle of negative feedback, ensure fast and efficient regulation of blood pressure. A key element in this process is the arterial baroreceptor reflex (BR). Disorders of BR play a significant role in the development and progression of many diseases of the cardiovascular system. Baroreflex sensitivity (BRS) and heart rate turbulence (HRT) are indicators of ANS function. Many clinical trials confirmed the value of ANS function assessment in risk stratification of patients with diseases such as hypertension, coronary artery disease, congestive heart failure, diabetes and stroke. Neither BRS nor HRT can be assessed in patients with atrial fibrillation and flutter, sino-atrial and atrioventricular blocks or in patients with pacemakers. Analysis of these indicators is therefore limited to a group of patients in sinus rhythm.

A new type of dual atrioventricular nodal nonreentrant tachycardia.

Dual atrioventricular nodal nonreentrant tachycardia (DAVNNT) is very rarely observed clinically. The first review of this arrhythmia was published in 2011 by Wang, where four types of DAVNNT were described. Our case report presents a phenomenon that has never been published before. We revealed a very specific sequence of double fire phenomenon, 1:1 atrioventricular (AV) conduction and AV block.

[Atrial fibrillation in athletes]. / Migotanie przedsionków u sportowców.

Atrial fibrillation (AF) is the most common cardiac arrhythmia affecting up to 1-1.5% of the population. Regular physical activity reduces the risk of cardiovascular diseases, however several studies have shown paradoxically increased incidence of AF in people practicing sport, especially in elite athletes. The results of studies suggest a U-shape relationship between sport and risk of arrhythmia. Minor regular exertion protects from arrhythmia through reduction in AF risk factors, while intense physical activity increases the risk of arrhythmia. The etiopathogenesis of arrhythmia in athletes has not been fully elucidated yet, but it is definitely multifactorial. Arrhythmia's occurrence may be related to adaptative remodeling of a heart, autonomic nervous system alteration as well as may be associated with other factors like inflammation or dyselectrolitaemia. Atrial Fibrillation in athletes should always be considered as an abnormality which requires further investigation as in small percentage of cases arrhythmia may be the first manifestation of a structural heart disease or chanellopathy potentially leading to sudden cardiac death. Taking into account several problems related to pharmacotherapy, AF ablation has become the first line treatment in athletes.

[Comparison of basic electrical features of ICD defibrillating leads implanted to right ventricular apex or right ventricular outflow track and septum]. / Porównanee podstawowych parametrów elektrycznych elektrod defibrylujacych wszczepianych do wierzcholka oraz do okolic drogi odplywu prawej komory serca.

UNLABELLED: Automatic implantable cardioverter-defibrillators (ICDs) are nowadays an essential tool for reducing mortality due to sudden cardiac death. Technological advances in the miniaturization of devices and lead fixation, and the development of surgical techniques has led to more frequent implantation of the defibrillation leads outside the right ventricular apex (RVA), especially in those patients requiring cardiac pacing, as data from large clinical trials showed that chronic RVA pacing is harmful, especially in heart failure subjects, who are an important target for the ICD. Very few studies have been published comparing the electrical characteristics of leads placed in the RVA versus those implanted outside the RVA, mainly to right ventricular outflow tract of the heart (RVA), hence any subsequent analysis of this issue seems to be a valuable addition to the available information in this topic. The aim of this study was to compare the electrical parameters of ICD leads implanted into the right ventricular apex (RVA), to those placed in one of the alternative sites: the right ventricular outflow tract (RVOT), or the area of the interventricular septum (RVS). MATERIAL AND METHODS: Retrospective analysis of medical data from a single centre (teaching hospital), which included 132 patients with ICD implanted in 2010-2011, both in primary and secondary prevention of sudden cardiac death. We compared the most important electrical parameters of the ICD system, as the resistance of the pacing system, resistance of high-voltage coil, the amplitude of the sensed beats and pacing threshold. In addition, we compared the time of implantation, X-ray fluoroscopy time and X-ray exposure. RESULTS: There were no statistically significant differences between the two analysed groups in terms of pacing-system resistance (601.012 vs. 602.7omega, p = 0,499), high-energy coil resistance (63.7omega vs. 67.22, p = 0,201), amplitude of sensed R-waves (14,6mV vs. 15.3mV, p = 0, 710) and the pacing threshold energy (0,368 microJ vs. 0.259 microJ, p = 0,803). Also the duration of implantation (123, 3 min vs. 123, 9 min, p = 0,940), fluoroscopy time (11,0 minutes vs. 8,6 minutes, p = 0,06) and dose exposure (1594, 5cGy/cm2 vs. 2094, 4cGy/cm2, p = 0,069) were comparable in both groups. CONCLUSIONS: Implantation of ICD leads to the RVOT/RVS is a safe procedure, and the basic electrical parameters of such systems are comparable to ICDs with lead implanted to the RVA.

[Postural orthostatic tachycardia syndrome (POTS)--pathophysiology, diagnostics, and treatment]. / Zespól posturalnej tachykardii ortostatycznej (POTS)--patofizjologia, rozpoznanie i leczenie.

Postural orthostatic tachycardia syndrome (POTS) is one of the most common presentation of orthostatic intolerance. The syndrome is described as a multifactorial affliction. Main symptoms consist of persistent orthostatic tachycardia (heart rate increase at least 30 beats/min, lasting at least 10 min after assumic vertical position) with high noradrenalin serum concentration (measured in stand-up position). Additionally patients with POTS tend to have lover total blood volume. POTS is generally classified into dysatonomia disorders Symptoms in patients affected with POTS are chronic. The syndrome occurs predominantly in young women (approximately 80%). Due to complexity and variable intensity of symptoms POTS can severely impair daily activity and quality of life in otherwise healthy people. The correct diagnosis and identification of potential pathophysiological mechanisms of POTS is necessary before treatment administration. Adequate therapy can significantly reduce symptoms giving the patients a chance for a normal life.