Machine learning-based prediction of in-hospital death for patients with takotsubo syndrome: The InterTAK-ML model

AIMS

Takotsubo syndrome (TTS) is associated with a substantial rate of adverse events. We sought to design a machine learning (ML)-based model to predict the risk of in-hospital death and to perform a clustering of TTS patients to identify different risk profiles.

METHODS AND RESULTS

A ridge logistic regression-based ML model for predicting in-hospital death was developed on 3482 TTS patients from the International Takotsubo (InterTAK) Registry, randomly split in a train and an internal validation cohort (75% and 25% of the sample size, respectively) and evaluated in an external validation cohort (1037 patients). Thirty-one clinically relevant variables were included in the prediction model. Model performance represented the primary endpoint and was assessed according to area under the curve (AUC), sensitivity and specificity. As secondary endpoint, a K-medoids clustering algorithm was designed to stratify patients into phenotypic groups based on the 10 most relevant features emerging from the main model. The overall incidence of in-hospital death was 5.2%. The InterTAK-ML model showed an AUC of 0.89 (0.85-0.92), a sensitivity of 0.85 (0.78-0.95) and a specificity of 0.76 (0.74-0.79) in the internal validation cohort and an AUC of 0.82 (0.73-0.91), a sensitivity of 0.74 (0.61-0.87) and a specificity of 0.79 (0.77-0.81) in the external cohort for in-hospital death prediction. By exploiting the 10 variables showing the highest feature importance, TTS patients were clustered into six groups associated with different risks of in-hospital death (28.8% vs. 15.5% vs. 5.4% vs. 1.0.8% vs. 0.5%) which were consistent also in the external cohort.

CONCLUSION

A ML-based approach for the identification of TTS patients at risk of adverse short-term prognosis is feasible and effective. The InterTAK-ML model showed unprecedented discriminative capability for the prediction of in-hospital death.

Impact of Atrial Fibrillation on Outcome in Takotsubo Syndrome: Data From the International Takotsubo Registry

Background

Atrial fibrillation (AF) is a major risk factor for mortality. The prevalence, clinical correlates, and prognostic impact of AF in Takotsubo syndrome (TTS) have not yet been investigated in a large patient cohort. This study aimed to investigate the prevalence, clinical correlates, and prognostic impact of AF in patients with TTS.

Methods and Results

Patients with TTS were enrolled from the International Takotsubo Registry, which is a multinational network with 26 participating centers in Europe and the United States. Patients were dichotomized according to the presence or absence of AF at the time of admission. Of 1584 patients with TTS, 112 (7.1%) had AF. The mean age was higher (P<0.001), and there were fewer women (P=0.046) in the AF than in the non‐AF group. Left ventricular ejection fraction was significantly lower (P=0.001), and cardiogenic shock was more often observed (P<0.001) in the AF group. Both in‐hospital (P<0.001) and long‐term mortality (P<0.001) were higher in the AF group. Multivariable Cox regression analysis revealed that AF was independently associated with higher long‐term mortality (hazard ratio, 2.31; 95% CI, 1.50–3.55; P<0.001). Among patients with AF on admission, 42% had no known history of AF before the acute TTS event, and such patients had comparable in‐hospital and long‐term outcomes compared with those with a history of AF.

Conclusions

In patients presenting with TTS, AF on admission is significantly associated with increased in‐hospital and long‐term mortality rates. Whether antiarrhythmics and/or cardioversion are beneficial in TTS with AF should thus be tested in a future trial.

Registration

URL: https://www.clinicaltrials.gov; Unique identifier: NCT01947621.

Coexistence and outcome of coronary artery disease in Takotsubo syndrome

AIMS

Takotsubo syndrome (TTS) is an acute heart failure syndrome, which shares many features with acute coronary syndrome (ACS). Although TTS was initially described with angiographically normal coronary arteries, smaller studies recently indicated a potential coexistence of coronary artery disease (CAD) in TTS patients. This study aimed to determine the coexistence, features, and prognostic role of CAD in a large cohort of patients with TTS.

METHODS AND RESULTS

Coronary anatomy and CAD were studied in patients diagnosed with TTS. Inclusion criteria were compliance with the International Takotsubo Diagnostic Criteria for TTS, and availability of original coronary angiographies with ventriculography performed during the acute phase. Exclusion criteria were missing views, poor quality of angiography loops, and angiography without ventriculography. A total of 1016 TTS patients were studied. Of those, 23.0% had obstructive CAD, 41.2% had non-obstructive CAD, and 35.7% had angiographically normal coronary arteries. A total of 47 patients (4.6%) underwent percutaneous coronary intervention, and 3 patients had acute and 8 had chronic coronary artery occlusion concomitant with TTS, respectively. The presence of CAD was associated with increased incidence of shock, ventilation, and death from any cause. After adjusting for confounders, the presence of obstructive CAD was associated with mortality at 30 days. Takotsubo syndrome patients with obstructive CAD were at comparable risk for shock and death and nearly at twice the risk for ventilation compared to an age- and sex-matched ACS cohort.

CONCLUSIONS

Coronary artery disease frequently coexists in TTS patients, presents with the whole spectrum of coronary pathology including acute coronary occlusion, and is associated with adverse outcome.

TRIAL REGISTRATION

ClinicalTrials.gov number: NCT01947621.

Prognostic impact of acute pulmonary triggers in patients with takotsubo syndrome: new insights from the International Takotsubo Registry

AIMS

Acute pulmonary disorders are known physical triggers of takotsubo syndrome (TTS). This study aimed to investigate prevalence of acute pulmonary triggers in patients with TTS and their impact on outcomes.

METHODS AND RESULTS

Patients with TTS were enrolled from the International Takotsubo Registry and screened for triggering factors and comorbidities. Patients were categorized into three groups (acute pulmonary trigger, chronic lung disease, and no lung disease) to compare clinical characteristics and outcomes. Of the 1670 included patients with TTS, 123 (7%) were identified with an acute pulmonary trigger, and 194 (12%) had a known history of chronic lung disease. The incidence of cardiogenic shock was highest in patients with an acute pulmonary trigger compared with those with chronic lung disease or without lung disease (17% vs. 10% vs. 9%, P = 0.017). In-hospital mortality was also higher in patients with an acute pulmonary trigger than in the other two groups, although not significantly (5.7% vs. 1.5% vs. 4.2%, P = 0.13). Survival analysis demonstrated that patients with an acute pulmonary trigger had the worst long-term outcome (P = 0.002). The presence of an acute pulmonary trigger was independently associated with worse long-term mortality (hazard ratio 2.12, 95% confidence interval 1.33-3.38; P = 0.002).

CONCLUSIONS

The present study demonstrates that TTS is related to acute pulmonary triggers in 7% of all TTS patients, which accounts for 21% of patients with physical triggers. The presence of acute pulmonary trigger is associated with a severe in-hospital course and a worse long-term outcome.

Age-Related Variations in Takotsubo Syndrome

BACKGROUND

Takotsubo syndrome (TTS) occurs predominantly in post-menopausal women but is also found in younger patients.

OBJECTIVES

This study aimed to investigate age-related differences in TTS.

METHODS

Patients diagnosed with TTS and enrolled in the International Takotsubo Registry between January 2011 and February 2017 were included in this analysis and were stratified by age (younger: ≤50 years, middle-age: 51 to 74 years, elderly: ≥75 years). Baseline characteristics, hospital course, as well as short- and long-term mortality were compared among groups.

RESULTS

Of 2,098 TTS patients, 242 (11.5%) patients were ≤50 years of age, 1,194 (56.9%) were 51 to 74 years of age, and 662 (31.6%) were ≥75 years of age. Younger patients were more often men (12.4% vs. 10.9% vs. 6.3%; p = 0.002) and had an increased prevalence of acute neurological (16.3% vs. 8.4% vs. 8.8%; p = 0.001) or psychiatric disorders (14.1% vs. 10.3% vs. 5.6%; p < 0.001) compared with middle-aged and elderly TTS patients. Furthermore, younger patients had more often cardiogenic shock (15.3% vs. 9.1% vs. 8.1%; p = 0.004) and had a numerically higher in-hospital mortality (6.6% vs. 3.6% vs. 5.1%; p = 0.07). At multivariable analysis, younger (odds ratio: 1.60; 95% confidence interval: 0.86 to 3.01; p = 0.14) and older age (odds ratio: 1.09; 95% confidence interval: 0.66 to 1.80; p = 0.75) were not independently associated with in-hospital mortality using the middle-aged group as a reference. There were no differences in 60-day mortality rates among groups.

CONCLUSIONS

A substantial proportion of TTS patients are younger than 50 years of age. TTS is associated with severe complications requiring intensive care, particularly in younger patients.

Intraventricular Thrombus Formation and Embolism in Takotsubo Syndrome

Objective:

Takotsubo syndrome (TTS) is characterized by acute left ventricular dysfunction, which can contribute to intraventricular thrombus and embolism. Still, prevalence and clinical impact of thrombus formation and embolic events on outcome of TTS patients remain unclear. This study aimed to investigate clinical features and outcomes of patients with and without intraventricular thrombus or embolism. Additionally, factors associated with thrombus formation or embolism, as well as predictors for mortality, were identified.

Approach and Results:

TTS patients enrolled in the International Takotsubo Registry at 28 centers in Australia, Europe, and the United States were dichotomized according to the occurrence/absence of intraventricular thrombus or embolism. Patients with intraventricular thrombus or embolism were defined as the ThrombEmb group. Of 1676 TTS patients, 56 (3.3%) patients developed intraventricular thrombus and/or embolism following TTS diagnosis (median time interval, 2.0 days [range, 0–38 days]). Patients in the ThrombEmb group had a different clinical profile including lower left ventricular ejection fraction, higher prevalence of the apical type, elevated levels of troponin and inflammatory markers, and higher prevalence of vascular disease. In a Firth bias-reduced penalized-likelihood logistic regression model apical type, left ventricular ejection fraction ≤30%, previous vascular disease, and a white blood cell count on admission >10×10 3 cells/μL emerged as independent predictors for thrombus formation or embolism.

Conclusions:

Intraventricular thrombus or embolism occur in 3.3% of patients in the acute phase of TTS. A simple risk score including clinical parameters associated with intraventricular thrombus formation or embolism identifies patients at increased risk.

Clinical Trial Registration:

URL: http://www.clinicaltrials.gov . Unique identifier: NCT01947621.

Clinical Predictors and Prognostic Impact of Recovery of Wall Motion Abnormalities in Takotsubo Syndrome: Results From the International Takotsubo Registry

Background

Left ventricular (LV) recovery in takotsubo syndrome (TTS) occurs over a wide‐ranging interval, varying from hours to weeks. We sought to investigate the clinical predictors and prognostic impact of recovery time for TTS patients.

Methods and Results

TTS patients from the International Takotsubo Registry were included in this study. Cut‐off for early LV recovery was determined to be 10 days after the acute event. Multivariable logistic regression was used to assess factors associated with the absence of early recovery. In‐hospital outcomes and 1‐year mortality were compared for patients with versus without early recovery. We analyzed 406 patients with comprehensive and serial imaging data regarding time to recovery. Of these, 191 (47.0%) had early LV recovery and 215 (53.0%) demonstrated late LV improvement. Patients without early recovery were more often male (12.6% versus 5.2%; P=0.011) and presented more frequently with typical TTS (76.3% versus 67.0%, P=0.040). Cardiac and inflammatory markers were higher in patients without early recovery than in those with early recovery. Patients without early recovery showed unfavorable 1‐year outcome compared with patients with early recovery (P=0.003). On multiple logistic regression, male sex, LV ejection fraction <45%, and acute neurologic disorders were associated with the absence of early recovery.

Conclusions

TTS patients without early LV recovery have different clinical characteristics and less favorable 1‐year outcome compared with patients with early recovery. The factors associated with the absence of early recovery included male sex, reduced LV ejection fraction, and acute neurologic events.

Clinical Trial Registration

URL: http://www.clinicaltrials.gov. Unique identifier: NCT01947621.

Present criteria for prophylactic ICD implantation: Insights from the EU-CERT-ICD (Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrillators in EUrope) project

BACKGROUND

The clinical effectiveness of primary prevention implantable cardioverter defibrillator (ICD) therapy is under debate. It is urgently needed to better identify patients who benefit from prophylactic ICD therapy. The EUropean Comparative Effectiveness Research to Assess the Use of Primary ProphylacTic Implantable Cardioverter Defibrillators (EU-CERT-ICD) completed in 2019 will assess this issue.

SUMMARY

The EU-CERT-ICD is a prospective investigator-initiated non-randomized, controlled, multicenter observational cohort study done in 44 centers across 15 European countries. A total of 2327 patients with heart failure due to ischemic heart disease or dilated cardiomyopathy indicated for primary prophylactic ICD implantation were recruited between 2014 and 2018 (>1500 patients at first ICD implantation, >750 patients non-randomized non-ICD control group). The primary endpoint was all-cause mortality, and first appropriate shock was co-primary endpoint. At baseline, all patients underwent 12‑lead ECG and Holter-ECG analysis using multiple advanced methods for risk stratification as well as documentation of clinical characteristics and laboratory values. The EU-CERT-ICD data will provide much needed information on the survival benefit of preventive ICD therapy and expand on previous prospective risk stratification studies which showed very good applicability of clinical parameters and advanced risk stratifiers in order to define patient subgroups with above or below average ICD benefit.

CONCLUSION

The EU-CERT-ICD study will provide new and current data about effectiveness of primary prophylactic ICD implantation. The study also aims for improved risk stratification and patient selection using clinical risk markers in general, and advanced ECG risk markers in particular.

Autonomic control of blood circulation in patients undergoing elective carotid endarterectomy

BACKGROUND

Internal carotid artery stenosis (ICAS) is associated with significantly higher risk of stroke. Autonomic function can be impaired in the presence of atheroma in the carotid sinus region. Two parameters of autonomic nervous system (ANS) function e.g. heart rate variability (HRV) and baroreflex sensitivity (BRS) are respected predictors of cardiovascular prognosis. We assessed the effect of elective unilateral carotid endarterectomy (CEA) on cardiovascular autonomic functions as a major prognostic factor for cardiovascular health.

METHODS

Nineteen patients indicated for CEA underwent formal autonomic assessment in the laboratory. Hemodynamic profiles, HRV and BRS were evaluated with the dedicated high-tech device Task Force Monitor before surgery (day-1) and postoperatively (day 3±1). Data were obtained during 5 min orthostatic challenge and subsequent 5 min in a supine position.

RESULTS

There were no significant early postoperative changes in evaluated parameters after CEA. There was a mild decrease of blood pressure and therefore only a slight increase in BRS. It was also possible to observe a rise in the value of total power and high frequency power.

CONCLUSION

In the early postoperative period, healing processes are occurring and the sympatho-vagal interaction is probably still unbalanced. Given the considerable clinical potential of BRS and HRV measurement, further short-term and, more importantly, long-term investigations are needed.

Orthostatic hypotension is associated with decreased cerebrospinal fluid levels of chromogranin A in early stage of Parkinson disease

An association between the CSF chromogranin A (CgA) and orthostatic blood pressure changes was investigated in 20 patients in the early stage of Parkinson disease (PD). There was a positive correlation between the CSF CgA and diastolic blood pressure change, when CSF CgA levels were lower in patients with orthostatic hypotension (OH). Decreased CSF CgA may be useful in predicting OH in the early stage of PD.

Lipidomic analysis of plasma, erythrocytes and lipoprotein fractions of cardiovascular disease patients using UHPLC/MS, MALDI-MS and multivariate data analysis

Differences among lipidomic profiles of healthy volunteers, obese people and three groups of cardiovascular disease (CVD) patients are investigated with the goal to differentiate individual groups based on the multivariate data analysis (MDA) of lipidomic data from plasma, erythrocytes and lipoprotein fractions of more than 50 subjects. Hydrophilic interaction liquid chromatography on ultrahigh-performance liquid chromatography (HILIC-UHPLC) column coupled with electrospray ionization mass spectrometry (ESI-MS) is used for the quantitation of four classes of polar lipids (phosphatidylethanolamines, phosphatidylcholines, sphingomyelins and lysophosphatidylcholines), normal-phase UHPLC-atmospheric pressure chemical ionization MS (NP-UHPLC/APCI-MS) is applied for the quantitation of five classes of nonpolar lipids (cholesteryl esters, triacylglycerols, sterols, 1,3-diacylglycerols and 1,2-diacylglycerols) and the potential of matrix-assisted laser desorption/ionization mass spectrometry (MALDI-MS) is tested for the fast screening of all lipids without a chromatographic separation. Obtained results are processed by unsupervised (principal component analysis) and supervised (orthogonal partial least squares) MDA approaches to highlight the largest differences among individual groups and to identify lipid molecules with the highest impact on the group differentiation.

Determination of nonpolar and polar lipid classes in human plasma, erythrocytes and plasma lipoprotein fractions using ultrahigh-performance liquid chromatography-mass spectrometry

A novel normal-phase (NP) ultrahigh-performance liquid chromatography-mass spectrometry (UHPLC/MS) method is developed for a separation and quantitation of nonpolar lipid classes occurring in human plasma, erythrocytes and plasma lipoprotein fractions. The baseline class separation of cholesteryl esters (CE), cholesterol, triacylglycerols (TG), regioisomers of 1,2- and 1,3-diacylglycerols (DG) and 1-monoacylglycerols (1-MG) is achieved using an optimized hexane - 2-propanol-acetonitrile mobile phase within 18min for all nonpolar lipid classes or only 9min excluding monoacylglycerols not detected in studied samples. The determination of individual nonpolar lipid classes is performed by the response factor approach and the use of dioleoyl ethylene glycol as a single internal standard. Polar lipid classes, such as phosphatidylglycerols (PG), phosphatidylethanolamines (PE), phosphatidylcholines (PC), sphingomyelins (SM) and lysophosphatidylcholines (LPC), are separated by hydrophilic interaction liquid chromatography (HILIC) using 5mmol/L aqueous ammonium acetate-methanol-acetonitrile gradient within 13minutes. The quantitation of polar lipid classes is done by a similar approach as for nonpolar lipid classes, but a different internal standard (sphingosyl PE d17:1/12:0) is used. The complementary information on fatty acyl profiles after the transesterification of the total lipid extract is obtained by gas chromatography with flame ionization detection (GC/FID). The applicability of developed methodology for fast and comprehensive characterization of blood lipidome is illustrated on samples of human plasma, erythrocytes, high-density lipoprotein (HDL), low-density lipoprotein (LDL) and very low-density lipoprotein (VLDL) fractions.

Detection of clopidogrel resistance using ADP induced aggregometry with specific inhibitor PGE1

BACKROUND

Antiaggregation therapy is still the most frequently used approach to prevent thrombotic events in cardiovascular diseases. It has a good clinical effect but increasing evidence shows high residual platelet aggregation activity in a number of patients. Laboratory methods only allow us to detect clopidogrel "non-responders" or "low responders". Recent methods are based on monitoring residual platelet aggregation activity (aggregation methods) or detecting the number of free epitopes for binding a specific monoclonal antibody such as vasodilator-stimulated phosphoprotein phosphorylation (VASP).

METHODS

The aims of our study were comparison light transmission aggregometry (LTA) and multiple electrode platelet aggregometry (MEA) with induction by ADP in concentrations of 20 micromol/L with or without prostaglandin E1 (PGE1) for monitoring clopidogrel resistance.

RESULTS

In the group of 84 patients with cardiovascular disease (CAD) studied, an impaired individual response to clopidogrel therapy was found 11.9% and 10.7% of the patients using MEA and LTA, respectively, induced by ADP with PGE1. The LTA and MEA methods with induction by ADP with PGE1 and without PGE1 were statistically compared using Spearman's nonparametric correlation analysis. Both methods with using PGE, showed a positive significant correlation (p = 0.003) in contrast with the results without PGE1 with a no significant correlation (p = 0.732).

CONCLUSIONS

The sensitivity for detecting clopidogrel resistance correlates well with other data in the literature suggesting that there are 5%-30% clopidogrel low-responders depending on the type of platelet function assay used and the criteria for defining a low-responder [16-18]. These results favor implementation of the ADP test with PGE1 by MEA specifically for identification of low-responders to clopidogrel.

Self care in patients with chronic heart failure. Pilot study - self care includes problems

AIM

The goal of this pilot study was to define the scope of therapeutic self-care demand in heart failure (HF) patients according to the concepts of self-care postulated by D.E. Orem and to determine the level of problems experienced and self-care in these patients.

METHODS

A questionnaire consisting of 7 areas with closed format questions was developed according to the definition. The level of patient problems and level of self-care actions were mapped in each area. The questionnaire was distributed at the hospital outpatient clinic. The study group consisted of 47 heart failure patients (14 women) with following characteristics: average age 68 years, average BMI 29.4, resynchronization therapy 21%, hypertension 69.8%, diabetes mellitus 25.6%, coronary artery disease 46.5%, dilated cardiomyopathy 46.5%, obesity 46.5%, smoking history 39.5% (present and past smoking together), other cardiac disease 16.28%, condition after myocardial infarction 27.8% (NYHA II 41%, NYHA III 56.8%, NYHA IV 2.2%).

RESULTS

The greatest problems were in the area of physical activity, sleep and fatigue, the least were in the area of chest pain and blood circulation. The greatest self-care agency was shown in the area of managing problems with physical activities and sleep, the lowest in the area of liquid intake and output. In the patients' subjective opinion, fatigue and sleep problems had the greatest impact on the quality of life. There were no substantial differences in either area based on gender.

CONCLUSIONS

The data can serve as a foundation for modifying the extent and structure of patient education for more comprehensive and more effective out‑patient treatment of HF.

Haemotherapy analysis: the Teaching Hospital Olomouc in 2006

AIMS

Annual evaluation of blood transfusion preparation administration at the University Hospital Olomouc, Czech Republic as a contribution to the European Union haemovigilance system.

METHODS

Analysis of blood transfusion preparations released from the Department of Blood Transfusion of the above university hospital and laboratory examination results in receivers of these products for the year 2006. Total hospital consumption and usage in particular medical disciplines in the hospital were assessed.

RESULTS

Red cell concentrates: in total 14 347 TU (deleucotised in 20.4 %). Departments according to usage: surgery, haematooncology, anaesthesiology and surgery intensive care department, and internal medicine department. Haemoglobin levels were above 100 g/L before blood transfusion administration in 24 % of cases. Platelets: in total 1 712 TU (100 % manufactured by apheresis, 56 % deleucotised). Platelet counts below 20 x 10(9)/L were found in all cases before platelet concentrate administration. Plasma: in total 5 959 TU to 1 297 of patients. Departments according to usage: surgery, anaesthesiology and surgery intensive care department, internal medicine and haematooncology. Two hundred and forty nine cases without coagulation parameter monitoring and 333 (25.67 %) patients with only 1 TU of administered plasma were found.

CONCLUSIONS

The incorrect indications for red cell transfusion preparations were found in eleven patients with haemoglobin levels above 130 g/L. Underdosing in 25.67 % of plasma administrations signifies dubious indications in these cases. Implementation of the haemovigilance system in practice is now mandatory for the Czech Republic after joining the European Union. Therefore more precise data and analysis of questionable cases with further education of staff in clinical departments are essential for the haemovigilance principle to be applied on a hospital basis in the Czech Republic.

[Malignant arrhythmia in a patient with variant (Prinzmetal's) angina pectoris]

Malignant arrhythmia is a frequent complication of myocardial ischemia due to the occurrence of coronary artery spasm. The paper describes a patient with variant angina pectoris with an ICD implant who was repeatedly resuscitated for circulatory arrest in malignant arrhythmia. During myocardial ischemia the ECG showed elevations in the ST segments in the region of the ventral cardiac wall, with the formation of permanent polymorphous chamber tachycardia. External defibrillation was necessary due to recurrent tachyarrhythmias. A spasm developed when the RIA (radio immuno assay) was introduced during coronarography. The spasm started in the periphery of the artery and extended as far as the area of bifurcation with RD, with transitory closure of the artery and the development of chamber tachycardia. The patient fully recovered after the addition of Ca-blocker, nitrate depot and the withdrawal of the beta-blocker.

Short-term spectral analysis of heart rate variability during supine-standing-supine test in patients with paroxysmal atrial fibrillation

The aim of the study was to assess the sympathovagal balance in group of 27 patients without significant structural heart disease after an attack of atrial fibrillation. The investigation was performed using spectral analysis of heart rate variability during examination under conditions of different orthostatic loads in single phases, called the supine-standing- supine test. The findings were compared with a group of healthy persons. These revealed a significantly decreased total spectral power (430.7 vs 1558.0 ms(2) supine1; 477.6 vs 1042,5 ms(2) standing; 567.5 vs 1948.5 ms(2) supine2), and spectral power of the high frequency spectral component (140.8 vs 619.3 ms(2) supine1; 96.2 vs 203.3 ms(2) standing; 186.3 vs 739.4 ms(2) supine2) in the studied group of patients in comparison with the control group.

Assessment of spectral analysis of heart rate variability in patients with history of atrial fibrillation by means of age-dependent parameters

Heart rate variability evaluation is a useful diagnostic tool for autonomic nervous balance assessment. The role of the autonomic nervous system in aetiology of atrial fibrillation is sometimes clear as a trigger from a patient's history, but mostly it acts as a modulating factor which is not easy to detect. The present study demonstrates results of spectral analysis of short-term heart rate variability during ortho-clinostatic tests processed by means of age-dependent parameters. An original telemetric system and a unique method for heart rate variability assessment, developed by the Faculty of Physical Culture, were applied for the first time to examine patients with the history of atrial fibrillation.