Severe Cardiac Autonomic Neuropathy Research Articles

A Study on QTc Prolongation as an Indicator of Cardiac Autonomic Neuropathy in Diabetic Patients at Bir Hospital, Nepal

Background: Diabetes mellitus frequently leads to cardiac autonomic neuropathy (CAN), a complication that disrupts heart rate control and vascular function, increasing the risk of silent myocardial ischemia and sudden cardiac death. Prolonged QTc interval on ECG has emerged as a reliable marker for detecting CAN.  Objective: To study the QTc prolongation in diabetes mellitus as an indicator of cardiac autonomic neuropathy.  Methodology: A cross-sectional study was conducted on 100 diabetic patients at NAMS, Bir Hospital, Nepal, from September 2021 to June 2022. Data on QTc intervals and other clinical parameters were analyzed using STATA 13.0 software.  Results: Among the 100 patients, 60% were diagnosed with CAN. Of these, 20% had severe CAN and 40% had early-stage CAN. Patients with severe CAN had a longer duration of diabetes and higher blood sugar levels compared to those without CAN. QTc interval was significantly prolonged in 58% of patients with CAN, indicating a strong correlation between QTc prolongation and CAN severity.  Conclusion: QTc interval prolongation is closely associated with the severity of CAN, making it a practical and efficient tool for early detection in diabetic patients. Recognizing prolonged QTc can help identify patients at higher risk of sudden cardiac death, emphasizing the need for further large-scale studies.

A Study of Cardiac Autonomic Neuropathy in Patient with Diabetes Mellitus.

Atherosclerotic coronary artery disease, diabetic cardiomyopathy, and cardiac autonomic neuropathy (CAN) are the three categories into which the cardiovascular consequences of diabetes can be grouped. After all other potential causes have been ruled out, cardiovascular autonomic neuropathy-often referred to as CAN in the literature-is defined as the impairment of autonomic regulation of the cardiovascular system. Finding people with CAN is crucial because, if detected early enough, comprehensive therapies focusing on lifestyle, glucose management, and cardiovascular risk factors can reverse the course of CAN and delay its progression. In order to better understand CAN in individuals with diabetes mellitus (DM) and how it relates to risk factors, the current study was conducted. Sixty consecutive diabetic patients were selected to be included in our study, diagnosed as per the American Diabetes Association (ADA) and the European Association for the Study of Diabetes. The presence of CAN was assessed with the help of Ewing's Battery, composed of five bedside tests. Out of 60 patients, a total of 53 patients (88.3%) with DM had CAN. Of these, 38.3% showed early CAN, 38.3% showed definite CAN, and 7% showed severe CAN. The abnormal E:I (exhalation/inhalation) ratio, noticed in 75% of patients, was the most frequently observed abnormal autonomic function test that tests the parasympathetic nervous system. The ECG's QTc interval prolongation provides good specificity for diagnosing CAN as well as assessing its severity, but the majority of cases showed low sensitivity. Since CAN has a significant association with mortality, every patient diagnosed with DM should be evaluated for CAN at the time of diagnosis as well as on an annual basis thereafter, as recommended by the ADA. Optimal glycemic management and lifestyle modification at the initial stages of diabetes may prevent CAN-related complications.

Artificial intelligence-enhanced electrocardiogram analysis for identifying cardiac autonomic neuropathy in patients with diabetes.

To develop and employ machine learning (ML) algorithms to analyse electrocardiograms (ECGs) for the diagnosis of cardiac autonomic neuropathy (CAN). We used motif and discord extraction techniques, alongside long short-term memory networks, to analyse 12-lead, 10-s ECG tracings to detect CAN in patients with diabetes. The performance of these methods with the support vector machine classification model was evaluated using 10-fold cross validation with the following metrics: accuracy, precision, recall, F1 score, and area under the receiver-operating characteristic curve (AUC). Among 205 patients (mean age 54 ± 17 years, 54% female), 100 were diagnosed with CAN, including 38 with definite or severe CAN (dsCAN) and 62 with early CAN (eCAN). The best model performance for dsCAN classification was achieved using both motifs and discords, with an accuracy of 0.92, an F1 score of 0.92, a recall at 0.94, a precision of 0.91, and an excellent AUC of 0.93 (95% confidence interval [CI] 0.91-0.94). For the detection of any stage of CAN, the approach combining motifs and discords yielded the best results, with an accuracy of 0.65, F1 score of 0.68, a recall of 0.75, a precision of 0.68, and an AUC of 0.68 (95% CI 0.54-0.81). Our study highlights the potential of using ML techniques, particularly motifs and discords, to effectively detect dsCAN in patients with diabetes. This approach could be applied in large-scale screening of CAN, particularly to identify definite/severe CAN where cardiovascular risk factor modification may be initiated.

Evaluation of association between time in range, a continuous glucose monitoring metric, and cardiac autonomic neuropathy in type 2 diabetes patients.

Time in range (TIR), a metric of continuous glucose monitoring (CGM) provides better information regarding the individual's glycemic variability than a static measure like glycated hemoglobin (HbA1c). TIR is emerging as an independent risk factor for diabetic complications, both microvascular and macrovascular complications independent of HbA1c. Hence, this study evaluates the association between TIR and cardiac autonomic neuropathy (CAN) in type 2 diabetic patients. A total of 42 patients with type 2 diabetes mellitus were enrolled in this study and underwent a 3-day CGM using the "FreeStyle Libre Pro Flash Glucose Monitoring System Sensor" along with tests for CAN within the 3 days of attaching the CGM. Out of 42 patients, 36 patients (85.7%) were diagnosed with CAN (early CAN 57.1% and definite CAN 28.6%) and the mean TIR was 64.4% ±23.5%. Out of those with TIR <70%, 42.9% were affected with definite CAN compared to only 14.3% among those with TIR >70%. Patients with more severe CAN were found to have a lower TIR (P = 0.115). The study found a high prevalence of cardiac autonomic neuropathy (CAN) of around 85.7% in type 2 diabetes patients. Lower TIR values were associated with a higher incidence of definite CAN (42.9% vs. 14.3% in TIR <70% vs. >70% groups). The findings suggest TIR is inversely associated with the presence and severity of cardiac autonomic neuropathy in type 2 diabetic patients and also a potential link between TIR and CAN severity.

Accuracy of autonomic symptoms in detection of severe cardiac autonomic neuropathy

Autonomic neuropathy is a troublesome complication of diabetes mellitus often is not addressed by the physicians. The aim was to see the accuracy of autonomic symptoms in the detection of severe cardiac autonomic neuropathy (CAN). This study was done in BIRDEM in 62 adult patients with type 2 diabetes mellitus and cardiac autonomic neuropathy. Cardiac autonomic neuropathy was detected clinically by heart rate and blood pressure change to maneuvers such as deep breathing, valsalva and standing. Eight symptoms of autonomic neuropathy, namely exercise intolerance, dizziness, dysphagia, abdominal bloating, constipa- tion, diarrhea, gustatory sweating and impotence were tested. In this study, impotence was the most common symptom (58%). There was no difference in the frequency of autonomic symptoms between severe and non-severe cardiac autonomic neuropathy. Taking clinical tests as gold standard, gustatory sweating had the highest specificity (96%) and constipation had the highest sensitivity (54.05%) in detection of severe cardiac autonomic neuropathy. Sensitivity increased to 78.37 when a constellation of symptoms were tested. Autonomic symptoms are common in patients with type 2 diabetes and cardiac autonomic neuropathy. Collection of symptoms was associated with a high sensitivity for detection of severe cardiac autonomic neuropathy. BSMMU J 2022; 15(1): 11-15

Clinical manifestations and evaluation of cardiac autonomic neuropathy in diabetes mellitus and metabolic syndrome

A serious complication of type 2 diabetes mellitus (T2DM) and metabolic syndrome (MetS) is a dysfunction of the autonomic nervous system, which requires early evaluation for the effective treatment. The possibilities of pulse oximetry, which allows to assess heart rate variability in screening of autonomic nervous system dysfunction in patients with T2DM and MetS, have not yet been studied sufficiently.Objective: to evaluate the pulse oximetry effectiveness by comparing its results with the data of quantitative autonomic testing (QAT) to detect cardiac autonomic neuropathy (CAN) and clarify its degree in patients with T2DM and MetS.Patients and methods. The study included 30 patients with T2DM (mean age 63±7.9 years), 30 patients with MetS (mean age 61.5±9.1 years), 30 subjects from the control group (mean age 49.7±9.3 years). Patients underwent pulse oximetry, basic cardiovascular reflex tests, assessment of subjective sensations according to the NSC questionnaire, the severity of neurological deficit in the legs according to the NIS-LL scale and neuropathic pain syndrome according to the NTSS-9 scale.Results and discussion. In the group of patients with T2DM, severe CAN was detected in 13.3% of patients, moderate – in 40%. In the group of patients with MetS, severe CAN was detected in 10% of patients, moderate – also in 10%. In the control group, signs of moderate CAN were detected only in 3.3% of patients. The results of pulse oximetry tests with deep breathing were comparable to the QAT results (p&lt;0.001). Conclusion. Pulse oximetry can be used to diagnose CAN.

A Study of Cardiovascular Autonomic Neuropathy in Adult Patients with Diabetes Mellitus at Levy Mwanawasa University Teaching Hospital

Cardiac autonomic neuropathy (CAN) is the diminished capacity of autonomic regulation of the cardiovascular system occurring in the presence of diabetes mellitus (DM) and in the absence of other aetiologies. Diabetes mellitus is a well- known cause of peripheral neuropathy. However, in comparison to somatic neuropathy, autonomic neuropathy is an under-diagnosed and under-treated chronic complication of diabetes mellitus despite its serious and significant contribution to morbidity and mortality in the diabetes mellitus population. A variety of tests, based on evaluation of the cardiovascular reflexes triggered by performing specific provocative manoeuvres, have been proposed to measure autonomic function. This study used four cardiovascular reflex tests to estimate appropriate autonomic function by examining heart rate, heart rate variation and the baroreceptor reflex. The aim of this study was to determine the presence of cardiovascular autonomic neuropathy in adult patients with diabetes mellitus at Levy Mwanawasa University Teaching Hospital in Lusaka, Zambia. Adult patients with diabetes mellitus, aged between 21 and 70 years, participated in this cross-sectional study. Four, non-invasive, cardiac autonomic reflex tests to assess for cardiac autonomic neuropathy were employed according to Ewing’s method. The parasympathetic function was analysed based on the heart rate response to paced deep breathing and to Valsalva manoeuvring. The sympathetic function was assessed by measuring heart rate and blood pressure response to postural change. Ewing`s criteria was used for the categorisation of cardiac autonomic neuropathy. Data were analysed using SPSS version 20. Continuous data were presented as means and standard deviation. Categorical data were analysed using a Fishers’ Exact Test (χ2) and a logistic regression was performed to verify the effects of diabetes mellitus’ duration, sex and age on the probability that the participants have cardiac autonomic neuropathy. A total of 52 patients participated in the study. The prevalence of Cardiac autonomic neuropathy was 48.1%. Out of 52 patients, 42.3% had definite cardiac autonomic neuropathy and 5.8% had severe cardiac autonomic neuropathy. Early cardiac autonomic neuropathy was observed in 34.6% of patients while 17.3% had no signs of cardiac autonomic neuropathy. The mean age of patients with cardiac autonomic neuropathy was 54.44 ± 10.90 years and the mean duration of diabetes mellitus from diagnosis was 5.36 ± 6.78 years. The probability of developing cardiac autonomic neuropathy increased with increasing age and hypertensive participants were more likely develop cardiac autonomic neuropathy (ѵ = 5.82, p = .001). In conclusion, cardiac autonomic neuropathy was present in a significant proportion of adult patients with diabetes mellitus at Levy Mwanawasa University Teaching Hospital, reflecting the increased morbidity encountered by this population. In order to improve patient quality of life and reduce disease burden, screening for cardiac autonomic neuropathy should be implemented using cardiovascular autonomic reflex tests which are relatively simple, safe and affordable.

Étude de la fréquence et des caractéristiques de la neuropathie autonome cardiaque chez un groupe d’adolescents et de jeunes adultes diabétiques de type 1 camerounais

AimWe aimed to describe cardiac autonomic neuropathy in a group of young Cameroonians type 1 diabetic patients. Patients and methodsWe conducted a descriptive cross-sectional study including consenting patients with type 1 diabetes and without any other comorbidity, who were followed-up at the type 1 diabetic children's clinic at the Yaoundé central hospital. Cardiac autonomic neuropathy was diagnosed and stage using the five functional tests described by Ewang et al., and the heart rate variability assessment. ResultsWe included 60 with a mean age of 18.6±4.9 years, 38.3% of female and a mean duration of diabetes of 5.9±5.1 years. Cardiac autonomic neuropathy was present in 96.7% of participants. Early, confirmed and severe cardiac autonomic neuropathy were found respectively in 8.3%, 86.7% and 1.7% of the patients. The most frequent clinical signs were exercise intolerance, alternating constipation and diarrhea and resting tachycardia. ConclusionCardiac autonomic neuropathy is common in young patients with type 1 diabetes. It is important to integrate the assessment of cardiac autonomic reflexes in type 1 diabetic patients’ follow-up.

Noninvasive exploration of Cardiac Autonomic Neuropathy by heart rate and blood pressure variability analysis in Type 2 Diabetic patients

Objectives:To determine the prevalence of asymptomatic cardiac autonomic neuropathy and its association with risk factors among patients with Type-2 diabetes mellitus (T2DM)Methods:The present case-control study was conducted at Department of Medicine, Civil Hospital, Dow University of Health Sciences (DUHS), Karachi, Pakistan during the period September` 2016 to May` 2017. After taking informed consent, subjects from both genders, 72 healthy controls and 72 clinically diagnosed T2DM diabetic patients, age between 30-65 years were selected by non-probability sampling technique. After taking medical history and demographics, Cardiac Autonomic Neuropathy (CAN) was identified by using Ewing`s cardiac autonomic reflex tests (CARTs) and association of risk factors was also investigated.Results:Severe CAN was identified in 13.9% of T2DM patients while in none of the healthy controls. HR response to deep breathing test was most sensitive (sensitivity= 90%) among all tests. The most common symptoms were Numbness (75.9%) and constipation (69%), resting heart rate and diabetes duration was significantly associated with DCAN.Conclusions:CAN was highly prevalent in diabetic population that may lead to nephropathy and retinopathy in future. It is highly recommended to use sensitive and simple CARTs in clinics for early detection and early treatment of CAN.

SCREENING AND ASSESSMENT OF CARDIAC AUTONOMIC NEUROPATHY IN LONG STANDING TYPE 2 DIABETIC WOMEN

Patients with long-standing diabetes mellitus undergoing surgical interventions are under considerable risk, hence posing a surgical challenge, as they may have cardiovascular and/or cardiac autonomic neuropathy (CAN). CAN is serious, often overlooked and underdiagnosed, with possible arrhythmias and silent ischemia that may be life threatening. The aim of this study was to screen for one of the underdiagnosed high-risk problems by assessment of CAN in long-standing type 2 diabetic women undergoing stressful situations. Cross-sectional study. Hundred type 2 diabetic women scheduled for major surgery were assessed by autonomic function tests. CAN was assessed by analyzing heart rate variations during three standard tests (deep breathing, lying to standing, and the valsalva maneuver). Sympathetic functions were assessed by checking orthostatic hypotension. The CAN score of each patient was analyzed. Continuous 24 h ECG monitoring was performed to evaluate arrhythmia, corrected QT (QTc), and QT dispersion (QTd). Transthoracic Doppler echocardiography, with a focus on left ventricular hypertrophy, diastolic, and systolic dysfunctions, was carried out. Patients were classified as having mild (with only one abnormal test) or severe CAN when two or more abnormal function tests were present. Exclusion criteria included any systemic illness that could affect the results of the study or the autonomic functions, smoking, hypertension, and patients with evident ischemia. CAN was detected in 70% of the patients studied, and 70% of them had a severe case of CAN. Postural hypotension was detected in 34% of the patients studied. QTc prolongation and QTd were frequent. ECG and Doppler echocardiography changes of left ventricular hypertrophy were more prevalent among patients with CAN. Diabetics with CAN were significantly older, had a longer duration of diabetes mellitus, and higher HbA1-c, higher pulse pressure, triglyceride, uric acid, and urinary albumin excretion rate. They also had a significantly increased left ventricular mass index and diastolic dysfunction. Middle-aged women with long-standing diabetes are vulnerable to CAN with postural hypotension and prolonged QTc intervals, QTd, and increased left ventricular mass index. Identification of CAN is crucial to prevent the hazards of cardiovascular insults during stressful situations, and cases with severe CAN may require coronary artery disease screening preoperatively.

DIAGNOSIS OF THE CARDIAC AUTONOMIC NEUROPATHY IN DIABETIC PATIENT

Cardiac autonomic neuropathy (CAN) is a very common diabetes-related complication that has a major effect on CVD, mortality and morbidity in patients with DM. Careful and timely testing of CAN with easy standard bedside tests in patients with DM 1 and 2 is critically important for early diagnoses and prophylaxes of further CV complications. Aim of the study was to evaluate the CAN characteristics in DM 1 versus DM 2 patients and to identify the relationship between CAN and typical diabetic complications. Materials and methods. A descriptive and comparative cross-sectional study was developed with 75 patients with Diabetes Mellitus (DM 1 — 30 patients, DM 2 — 45 patients) who were hospitalized to the endocrinology department for treatment. All patients were investigated routinely – complains, anamnestic data, objective examination, lab and instrumental examination. For defining of CAN next five classical tests were done (cardiac autonomic reflex testing (CART)): Evaluating of the Resting tachycardia; Heart rate response to deep breathing; Valsalva maneuver; Systolic blood pressure response to standing; Diastolic blood pressure response to sustained handgrip. Results and discussions. Absence of CAN, according to proposed score, was defined in those patients without clinical features of CVD. 46.8% of all patients presented with early and definitive CAN, while the higher prevalence of definitive CAN was diagnosed in DM 2 patients. Severe CAN was confirmed more often in DM 2 patients also. Coexistence of CAN and peripheral neuropathy was higher in patients with DM 1 than in DM 2 patients. Among DM 1 patients with CAN only 11.8% persons had not sensory peripheral neuropathy, while 29.7% DM 2 patients with CAN, were free of sensory peripheral neuropathy. Positive correlations were found between the duration of the DM and manifestations of CAN in patients with DM II, the development of sensory polyneuropathy, retinopathy and CAN in patients with DM I, and this diabetic complication preceded the clinical manifestations of peripheral neuropathy. Thus, the proposed set of diagnostic measures should be obviously and easily used for the timely diagnosis of CAN in diabetic patients, especially in asymptomatic cases, and objectively assessing the effectiveness of the therapy.

573-P: Diagnostic Performance of Heart Rate Variability for Detecting Diabetic Cardiac Autonomic Neuropathy

Heart rate variability (HRV) has been considered as a useful tool for detecting cardiac autonomic neuropathy (CAN) and predicting mortality in individuals with diabetes. We evaluated its diagnostic performance for CAN in a hospital-based cohort. CAN was defined and classified according to Ewing’s criteria using standard 5 cardiovascular reflex test. HRV and power spectral density (PSD) were assessed by DiCAN (Medicore, Seoul, Korea); and diagnostic performance of Standard Deviation Normal to Normal (SDNN) and each PSD domain (total power, TP; very low frequency, VLF; low frequency, LF; high frequency, HF) were evaluated using receiver operating characteristic (ROC) analysis and Youden's index. After excluding subjects with insufficient data, 2,209 diabetic patients were included the analyses (mean age, 60 ± 11 years; men, 49.6%). Early, definite, and severe CAN were detected in 38.7%, 10.4%, and 4.1% in them. Multivariable Poisson regression adjusted for age and sex showed that all SDNN, TP, VLF, LF, and HF were decreased as severity of CAN increased (P&amp;lt;0.001). Their area under curve of ROC for diagnosis of definite CAN was 0.67 (95% confidence interval, 0.64 - 0.70), 0.71 (0.68 - 0.74), 0.68 (0.65 - 0.71), 0.73 (0.70 - 0.75), and 0.68 (0.65 - 0.71), respectively; and their sensitivity was 0.74, 0.80, 0.70, 0.70, and 0.79, respectively in this analysis. For detection of early CAN, their sensitivity was more decreased to 0.71, 0.64, 0.52, 0.64, and 0.74, respectively. In conclusion, even though there was significant decrease in HRV according to severity of CAN, HRV could not detect about 30% of diabetic subjects with CAN especially in the case with early impairment. Further studies evaluating diagnostic performance of HRV in various populations are needed. Disclosure B. Koo: None. M. Moon: None.

A Study of Cardiac Autonomic Neuropathy in Patients with Type 2 Diabetes Mellitus: A Northeast India Experience.

Aim:To investigate the prevalence and the risk factors for cardiac autonomic neuropathy (CAN) in type 2 diabetes mellitus (DM) patients.Study Design:Cross-sectional cohort study.Place and Duration of Study:This study was conducted in the Department of Endocrinology, Gauhati Medical College and Hospital, Assam, India between December 2016 to March 2018.Methodology:We included 100 patients (60 males and 40 females; age range: 36–72 years) with type 2 DM. Their clinical, biochemical, and metabolic parameters were analyzed and assessment of CAN were done based on the Ewing's criteria.Results:Out of 100 patients, 60 were males and 40 were females. The mean age of the patients was 53.3 ± 10.37 years (36–72 years) and the mean duration of diabetes was 9.03 ± 6.4 years (6 months–25 years). Patients were divided into two groups: “without CAN” (CAN−) and “with CAN” (CAN+). The prevalence of CAN was 70%, with early CAN in 25%, definite CAN in 24%, and severe CAN in 21% cases The patients with CAN were older (P = 0.0005), had longer diabetes duration (11.56 vs. 3.13; P = 0.0001), higher creatinine (P < 0.0001), and lower estimated glomerular filtration rate (eGFR) (P = 0.0001) compared to patients without CAN. Retinopathy, peripheral neuropathy, and nephropathy were common in CAN + patients. On multiple logistic regression analysis, duration of diabetes [odds ratio (OR); 6.7, P < 0.0001), older age (OR; 1.07, P < 0.016), and lower eGFR (OR; 0.97, P < 0.03) were risk factors for CAN.Conclusion:CAN is a common microvascular complication in type 2 DM with duration of diabetes, age, and severity of nephropathy being its significant determinants.

Longitudinal Relationship Between Retinal Diabetic Neurodegeneration and Progression of Diabetic Retinopathy in Patients With Type 2 Diabetes

To investigate the longitudinal relationship between diabetic retinal neurodegeneration and the progression of diabetic retinopathy (DR) by measuring macular ganglion cell-inner plexiform layer (mGCIPL) thickness in patients with type 2 diabetes (T2DM). Retrospective cohort study. T2DM patients with no DR or mild nonproliferative DR (NPDR) followed up for ≥4 years were included in this study. DR was graded according to retinal photography, and mean parafoveal mGCIPL thickness was measured using optical coherence tomography with at least a 6-month interval from baseline. Hazard ratios (HR) for predicting 2-step progression and development of proliferative DR (PDR) were calculated using Cox proportional hazard modeling using baseline clinical factors. Of 87 eyes of T2DM patients, 39 (44.8%) exhibited 2-step DR progression and 6 (6.9%) experienced progression to PDR. Patients with DR progression exhibited longer T2DM duration, thinner mGCIPL, greater mGCIPL thinning rate, severe cardiac autonomic neuropathy (CAN), lower peripheral nerve-conduction velocity, and higher glycated hemoglobin A1c level. Multivariate regression modeling revealed that baseline mGCIPL thickness (HR= 0.94), mGCIPL thinning rate (HR= 1.924), CAN score (HR= 1.248), and conduction velocity of peripheral nerves (HR= 0.894) were significant predictive factors for DR progression (area under the curve= 0.92). Progressive loss of mGCIPL is an independent risk factor for progression in early-stage DR. Further assessment of autonomic and peripheral nerve functions can increase sensitivity in predicting aggravation of DR in patients with T2DM.

Minimal ensemble based on subset selection using ECG to diagnose categories of CAN

Background and objective:Early diagnosis of cardiac autonomic neuropathy (CAN) is critical for reversing or decreasing its progression and prevent complications. Diagnostic accuracy or precision is one of the core requirements of CAN detection. As the standard Ewing battery tests suffer from a number of shortcomings, research in automating and improving the early detection of CAN has recently received serious attention in identifying additional clinical variables and designing advanced ensembles of classifiers to improve the accuracy or precision of CAN diagnostics. Although large ensembles are commonly proposed for the automated diagnosis of CAN, large ensembles are characterized by slow processing speed and computational complexity. This paper applies ECG features and proposes a new ensemble-based approach for diagnosis of CAN progression. MethodsWe introduce a Minimal Ensemble Based On Subset Selection (MEBOSS) for the diagnosis of all categories of CAN including early, definite and atypical CAN. MEBOSS is based on a novel multi-tier architecture applying classifier subset selection as well as the training subset selection during several steps of its operation. Our experiments determined the diagnostic accuracy or precision obtained in 5 × 2 cross-validation for various options employed in MEBOSS and other classification systems. ResultsThe experiments demonstrate the operation of the MEBOSS procedure invoking the most effective classifiers available in the open source software environment SageMath. The results of our experiments show that for the large DiabHealth database of CAN related parameters MEBOSS outperformed other classification systems available in SageMath and achieved 94% to 97% precision in 5 × 2 cross-validation correctly distinguishing any two CAN categories to a maximum of five categorizations including control, early, definite, severe and atypical CAN. ConclusionsThese results show that MEBOSS architecture is effective and can be recommended for practical implementations in systems for the diagnosis of CAN progression.

Liver cirrhosis-effect on QT interval and cardiac autonomic nervous system activity.

AIMTo examine the impact of liver cirrhosis on QT interval and cardiac autonomic neuropathy (CAN).METHODSA total of 51 patients with cirrhosis and 51 controls were examined. Standard 12-lead electrocardiogram recordings were obtained and QT as well as corrected QT interval (QTc) and their dispersions (dQT, dQTc) were measured and calculated using a computer-based program. The diagnosis of CAN was based upon the battery of the tests proposed by Ewing and Clarke and the consensus statements of the American Diabetes Association. CAN was diagnosed when two out of the four classical Ewing tests were abnormal.RESULTSQT, QTc and their dispersions were significantly longer (P < 0.01) in patients with cirrhosis than in controls. No significant differences in QT interval were found among the subgroups according to the etiology of cirrhosis. Multivariate regression analysis after controlling for age, gender and duration of cirrhosis demonstrated significant association between QT and presence of diabetes mellitus [standardized regression coefficient (beta) = 0.45, P = 0.02] and treatment with diuretics (beta = 0.55, P = 0.03), but not with the Child-Pugh score (P = 0.54). Prevalence of CAN was common (54.9%) among patients with cirrhosis and its severity was associated with the Child-Pugh score (r = 0.33, P = 0.02). Moreover, patients with decompensated cirrhosis had more severe CAN that those with compensated cirrhosis (P = 0.03). No significant association was found between severity of CAN and QT interval duration.CONCLUSIONPatients with cirrhosis have QT prolongation. Treatment with diuretics is associated with longer QT. CAN is common in patients with cirrhosis and its severity is associated with severity of the disease.

Cardiac autonomic neuropathy: Risk factors, diagnosis and treatment.

Cardiac autonomic neuropathy (CAN) is a serious complication of diabetes mellitus (DM) that is strongly associated with approximately five-fold increased risk of cardiovascular mortality. CAN manifests in a spectrum of things, ranging from resting tachycardia and fixed heart rate (HR) to development of “silent” myocardial infarction. Clinical correlates or risk markers for CAN are age, DM duration, glycemic control, hypertension, and dyslipidemia (DLP), development of other microvascular complications. Established risk factors for CAN are poor glycemic control in type 1 DM and a combination of hypertension, DLP, obesity, and unsatisfactory glycemic control in type 2 DM. Symptomatic manifestations of CAN include sinus tachycardia, exercise intolerance, orthostatic hypotension (OH), abnormal blood pressure (BP) regulation, dizziness, presyncope and syncope, intraoperative cardiovascular instability, asymptomatic myocardial ischemia and infarction. Methods of CAN assessment in clinical practice include assessment of symptoms and signs, cardiovascular reflex tests based on HR and BP, short-term electrocardiography (ECG), QT interval prolongation, HR variability (24 h, classic 24 h Holter ECG), ambulatory BP monitoring, HR turbulence, baroreflex sensitivity, muscle sympathetic nerve activity, catecholamine assessment and cardiovascular sympathetic tests, heart sympathetic imaging. Although it is common complication, the significance of CAN has not been fully appreciated and there are no unified treatment algorithms for today. Treatment is based on early diagnosis, life style changes, optimization of glycemic control and management of cardiovascular risk factors. Pathogenetic treatment of CAN includes: Balanced diet and physical activity; optimization of glycemic control; treatment of DLP; antioxidants, first of all α-lipoic acid (ALA), aldose reductase inhibitors, acetyl-L-carnitine; vitamins, first of all fat-soluble vitamin B1; correction of vascular endothelial dysfunction; prevention and treatment of thrombosis; in severe cases-treatment of OH. The promising methods include prescription of prostacyclin analogues, thromboxane A2 blockers and drugs that contribute into strengthening and/or normalization of Na+, K+-ATPase (phosphodiesterase inhibitor), ALA, dihomo-γ-linolenic acid (DGLA), ω-3 polyunsaturated fatty acids (ω-3 PUFAs), and the simultaneous prescription of ALA, ω-3 PUFAs and DGLA, but the future investigations are needed. Development of OH is associated with severe or advanced CAN and prescription of nonpharmacological and pharmacological, in the foreground midodrine and fludrocortisone acetate, treatment methods are necessary.

Advanced Clustering Method for Neurological Assessment Using Graph Models

This work represents an advance in sophisticated methods used to detect severe cardiac autonomic neuropathy (CAN). It applies clustering based on a graph model to ECG biosignal processing results in order to optimise classification performance. Severe CAN represents a particularly significant neurological problem in diabetes healthcare as it requires urgent intervention to reduce the risk of sudden cardiac death. The introduction of a new Clustering System Based on Graphs (CSBG) combined with heart rate features determined from recorded ECG biosignals was intended as a means of enhancing the effectiveness of the diagnosis of severe CAN. Here we study a novel heart rate descriptor – Allan exponents (AE) to determine the effectiveness of CSBG and compare the results with performance of other classification and clustering systems available in Sage. The best outcomes were obtained by CSBG in combination with AE, which improved the F measure of classification performance to 0.92 and outperformed several other classification and clustering systems in our experiments.

Assessment of cardiac autonomic neuropathy in long standing type 2 diabetic women

Patients with long standing DM undergoing surgical interventions are put under great challenge as they may have cardiovascular and/or cardiac autonomic neuropathy (CAN). CAN is serious, often overlooked and under diagnosed, with possible arrhythmias and silent ischemia that threaten life. Assessment of CAN in long standing type 2 diabetic women undergoing major surgery. Cross sectional study. One hundred and six type 2 diabetic women scheduled for major surgery were assessed by the autonomic function tests. Only one hundred cases completed the study. CAN was assessed by analyzing HR variations during three standard tests (deep breathing, lying to standing and valsalva maneuver). Sympathetic functions were assessed by checking orthostatic hypotension. The CAN score of each patient was analyzed. Continuous 24 hour ECG monitoring (Holter) was done to evaluate ischemia, arrhythmia, QTc and QTd. Transthoracic Doppler echocardiography, stressing on LVH, diastolic and systolic dysfunctions were carried out. Cases were classified as mild (with only one abnormal test) or severe CAN when two or more abnormal function tests were present. Exclusion criteria include any systemic illness that can affect the study results or the autonomic functions, smoking and HTN. CAN was detected in 70% of the studied cases, and 70% were severe CAN. Postural hypotension was detected in 34% of the studied cases. QTc prolongation and QT dispersion were frequent. ECG and Doppler echocardiography changes of LVH were more prevalent among patients with CAN. Diabetics with CAN were significantly older had longer duration of DM and higher HbA1-c, higher pulse pressure, triglyceride, uric acid and urinary albumin excretion rate. They also had significant increased LVM index, diastolic dysfunction and myocardial ischemia. Middle aged women with long standing diabetes are vulnerable to CAN with postural hypotension and prolonged QTc intervals, QT dispersion, and increased LVMI and myocardial ischemia. Identification of CAN is crucial to exercise prevention against hazards of CV insults during stressful situation as surgery.

Screening and assessment of cardiac autonomic neuropathy in long-standing type 2 diabetic women

Abstract Background Patients with long-standing diabetes mellitus undergoing surgical interventions are under considerable risk, hence posing a surgical challenge, as they may have cardiovascular and/or cardiac autonomic neuropathy (CAN). CAN is serious, often overlooked and underdiagnosed, with possible arrhythmias and silent ischemia that may be life threatening. Objectives The aim of this study was to screen for one of the underdiagnosed high-risk problems by assessment of CAN in long-standing type 2 diabetic women undergoing stressful situations. Study design Cross-sectional study. Patients and methods Hundred type 2 diabetic women scheduled for major surgery were assessed by autonomic function tests. CAN was assessed by analyzing heart rate variations during three standard tests (deep breathing, lying to standing, and the valsalva maneuver). Sympathetic functions were assessed by checking orthostatic hypotension. The CAN score of each patient was analyzed. Continuous 24 h ECG monitoring was performed to evaluate arrhythmia, corrected QT (QTc), and QT dispersion (QTd). Transthoracic Doppler echocardiography, with a focus on left ventricular hypertrophy, diastolic, and systolic dysfunctions, was carried out. Patients were classified as having mild (with only one abnormal test) or severe CAN when two or more abnormal function tests were present. Exclusion criteria included any systemic illness that could affect the results of the study or the autonomic functions, smoking, hypertension, and patients with evident ischemia. Results CAN was detected in 70% of the patients studied, and 70% of them had a severe case of CAN. Postural hypotension was detected in 34% of the patients studied. QTc prolongation and QTd were frequent. ECG and Doppler echocardiography changes of left ventricular hypertrophy were more prevalent among patients with CAN. Diabetics with CAN were significantly older, had a longer duration of diabetes mellitus, and higher HbA1-c, higher pulse pressure, triglyceride, uric acid, and urinary albumin excretion rate. They also had a significantly increased left ventricular mass index and diastolic dysfunction. Conclusion Middle-aged women with long-standing diabetes are vulnerable to CAN with postural hypotension and prolonged QTc intervals, QTd, and increased left ventricular mass index. Identification of CAN is crucial to prevent the hazards of cardiovascular insults during stressful situations, and cases with severe CAN may require coronary artery disease screening preoperatively.