Is Stroke risk analysis (SRA) a reliable method for predicting atrial fibrillation? A systematic review.

INTRODUCTION: Atrial fibrillation is responsible for a considerable number of cases of cardioembolism, accounting for 17% to 30% of the etiologies of all strokes. The software known as Stroke Risk Analysis (SRA) detects patients at high risk of paroxysmal atrial fibrillation by analyzing a continuous electrocardiogram recorded over different periods of time. OBJECTIVES: This article aims to carry out a systematic review investigating the effectiveness of the SRA method in predicting the risk of stroke patients having paroxysmal atrial fibrillation as the cause of the event. METHODS: The methods correspond to the format of the International Prospective Register of Systematic Reviews Protocol, according to CRD Identification Code: CRD42021253974. A systematic search was carried out in BMJB, PubMed/MEDLINE, Science Direct and LILACS. Six cohort studies met the inclusion criteria, representing a total of 2,088 participants with stroke, and compared the detection of patients with paroxysmal atrial fibrillation on the continuous recording electrocardiogram with a time variation of 1 to 48h with the use of SRA. RESULTS: Studies have shown that SRA has a high negative predictive value (between 96 and 99.1%) and can contribute to the selection of patients at high risk of paroxysmal atrial fibrillation to be referred for implantable cardiac monitoring to continue the investigation. CONCLUSIONS: A sequential combination of SRA with implantable cardiac monitoring is a promising strategy for detecting undiagnosed paroxysmal atrial fibrillation. Thus, the SRA can act as a cost-effective pre-selection tool to identify patients at higher risk of having paroxysmal atrial fibrillation as a possible cause of stroke and who may benefit from implantable cardiac monitoring. However, the lack of randomized studies is a limitation that must be considered.

Functional electrical stimulation cycling-based muscular evaluation method in mechanically ventilated patients.

BACKGROUND: Intensive care acquired muscle weakness is a common feature in critically ill patients. Beyond the therapeutic uses, FES-cycling could represent a promising nonvolitional evaluation method for detecting acquired muscle weakness. OBJECTIVES: To assess whether FES-cycling is able to identify muscle dysfunctions, and to evaluate the survival rate in patients with detected muscle dysfunction. METHODS: A prospective observational study was carried out, with 29 critically ill patients and 20 healthy subjects. Maximum torque and power achieved were recorded, in addition to the stimulation cost, and patients were followed up for six months. RESULTS: Torque (2.64 [1.53 to 4.81] vs 6.03 [4.56 to 6.73] Nm) and power (3.31 [2.33 to 6.37] vs 6.35 [5.22 to 10.70] watts) were lower and stimulation cost (22 915 [5069 to 37 750] vs 3411 [2080 to 4024] µC/W) was higher in patients compared to healthy people (p < 0.05). Surviving patients showed a nonsignificant difference in power and torque in relation to nonsurvivors (p > 0.05), but they had a lower stimulation cost (4462 [3598 to 11 788] vs 23 538 [10 164 to 39 836] µC/W) (p < 0.05). In total, 34% of all patients survived during the six months of follow-up. Furthermore, 62% of patients with a stimulation cost below 15 371 µC/W and 7% of patients with a stimulation cost above 15 371 µC/W survived. CONCLUSIONS: FES-cycling has good sensitivity and specificity for detecting muscle disorders. Critical patients have low torque and power and a high stimulation cost. Stimulation cost is related to survival. A low stimulation cost was related to a 3 times greater chance of survival.

Hematological Changes during Seven Days of Hospitalization in Patients with Acute Myocardial Infarction. / Alterações Hematológicas durante um Período de Sete Dias de Internação em Pacientes com Infarto Agudo do Miocárdio.

BACKGROUND: Acute myocardial infarction is a major cause of mortality worldwide, and atherosclerotic plaque formation is the main pathophysiological mechanism, which results in chronic inflammation that induces erythrocyte maturation and may cause an increase in the red cell distribution width (RDW) index. OBJECTIVE: Evaluate the role of the anisocytosis index in patients with acute myocardial infarction in both types of infarctions as a predictor of severity. METHODS: Patients were included in the study according to the inclusion/exclusion criteria, following the hospital routine based on their clinical and laboratory history. Statistical analyzes were performed according to each variable. All conclusions were drawn considering the significance level of 5%. RESULTS: During the follow-up period, in the 349 patients analyzed, the mortality rate was associated with the variables RDW (CV) and RDW (SD), in those patients who died, an increase was noted, as demonstrated in the multivariate model, for the effects of an acute ST elevation myocardial infarction and the RDW, adjusted for confounding factors (p-value = 0.03 and 0.04). In contrast, the total number of erythrocytes (p-value = 0.00) and hemoglobin (p-value = 0.03) showed a decrease during severe patients' hospitalization. CONCLUSION: The anisocytosis index was a predictive factor of mortality and can be used as an indicator of worse prognosis in patients with acute myocardial infarction.

FUNDAMENTO: O infarto agudo do miocárdio é uma das principais causas de mortalidade em todo o mundo e a formação de placa aterosclerótica é o principal mecanismo fisiopatológico, que resulta em inflamação crônica e induz a maturação eritrocitária, podendo causar aumento no índice de amplitude de distribuição dos glóbulos vermelhos (RDW). OBJETIVO: Avaliar o papel do índice de anisocitose em pacientes com infarto agudo do miocárdio em ambos os tipos de infarto como preditor de gravidade. MÉTODOS: Os pacientes foram incluídos no estudo de acordo com os critérios de inclusão e exclusão, seguindo a rotina hospitalar baseada na história clínica e laboratorial. As análises estatísticas foram realizadas de acordo com cada variável. Chegou-se a todas as conclusões considerando o nível de significância de 5%. RESULTADOS: Durante o período de acompanhamento, nos 349 pacientes analisados, a taxa de mortalidade esteve associada às variáveis RDW (CV) e RDW (SD). Nos pacientes que foram a óbito, notou-se aumento, conforme demonstrado no modelo multivariado, nos efeitos de um infarto agudo do miocárdio com supradesnivelamento do segmento ST e RDW, ajustado para fatores de confusão (valor-p = 0,03 e 0,04). Em contrapartida, o número total de eritrócitos (valor-p = 0,00) e hemoglobina (valor-p = 0,03) apresentou diminuição durante a internação de pacientes graves. CONCLUSÃO: O índice de anisocitose foi fator preditivo de mortalidade e pode ser utilizado como indicador de pior prognóstico em pacientes com infarto agudo do miocárdio.

Autonomic dysfunction in COVID-19 patients receiving mechanical ventilation: A cross-sectional study.

BACKGROUND: Coronavirus disease 2019 (COVID-19) can damage cardiac tissue by increasing troponin levels and inducing arrhythmias, myocarditis, and acute coronary syndrome. OBJECTIVES: To analyze the impact of COVID-19 on cardiac autonomic control in mechanically ventilated intensive care unit (ICU) patients. DESIGN AND SETTING: This cross-sectional analytical study of ICU patients of both sexes receiving mechanical ventilation was conducted in a tertiary hospital. METHODS: Patients were divided into COVID-19-positive (COVID(+)) and COVID-19-negative (COVID(-)) groups. Clinical data were collected and heart rate variability (HRV) records obtained using a heart rate monitor. RESULTS: The study sample comprised 82 subjects: 36 (44%) in the COVID(-) group (58.3% female; median age, 64.5 years) and 46 (56%) in the COVID(+) group (39.1% females; median age, 57.5 years). The HRV indices were lower than the reference values. An intergroup comparison identified no statistically significant differences in the mean normal-to-normal (NN) interval, standard deviation of the NN interval, or root mean square of successive differences in NN intervals. The COVID(+) group had an increased low frequency (P = 0.05), reduced high frequency (P = 0.045), and increased low frequency/high frequency (LF/HF) ratio (P = 0.048). There was a weak positive correlation between LF/HF and length of stay in the COVID(+) group. CONCLUSION: Patients who received mechanical ventilation had lower overall HRV indices. COVID(+) patients who received mechanical ventilation had lower vagal HRV components. These findings likely indicate clinical applicability, as autonomic control impairments are associated with a greater risk of cardiac death.

Impaired Cardiovascular Parameters in Resistance Training Practitioners Who Take Ergogenic Aids.

BACKGROUND: Although there are studies on blood pressure (BP) and autonomic cardiac control (ACC) impairments caused by ergogenic aids, research has scarcely addressed this analysis during sleep. This study analyzed BP and ACC during sleep and wake periods in three groups of resistance training (RT) practitioners: ergogenic aid non-users, thermogenic supplement (TS) self-users, and anabolic-androgenic steroid (AAS) self-users. METHODS: RT practitioners were selected for the Control Group (CG; n = 15), TS self-users Group (TSG; n = 15), and AAS self-users Group (AASG; n = 15). All individuals underwent cardiovascular Holter monitoring (BP, ACC) during sleep and wake periods. RESULTS: The maximum systolic BP (SBP) during sleep was higher in AASG (p < 0.01) than CG (p < 0.001). CG had lower mean diastolic BP (DBP) than TSG (p < 0.01) and lower mean SBP (p = 0.009) than the other groups. Additionally, CG had higher values (p < 0.01) than TSG and AASG for SDNN and pNN50 during sleep. HF, LF, and LF/HF ratio values during sleep were statistically different in CG (p < 0.001) from the other groups. CONCLUSIONS: Our findings demonstrate that high doses of TS and AAS can impair cardiovascular parameters during sleep in RT practitioners who take ergogenic aids.

Heart rate variability as a predictor of mechanical ventilation weaning outcomes.

BACKGROUND: Delays in the mechanical ventilation (MV) weaning process increase mortality. The spontaneous breathing test is the gold standard to assess weaning and extubation success, although it has approximately 85% accuracy. Studies have demonstrated a correlation between decreased heart rate variability (HRV) and weaning failure. OBJECTIVES: To assess the usefulness of HRV as a predictor of MV weaning outcomes. METHODS: Cross-sectional analytical study in adults of both sexes on MV in intensive care unit (ICU) stay. Patients were divided into weaning success and failure groups. Clinical data were collected, and HRV records were obtained with a heart rate monitor. RESULTS: The study included 68 individuals - 91.1% in the weaning success group and 8.9% in the failure group. All HRV indices analyzed in both groups were lower than the reference values. No statistical difference was found in the mean RR interval (RRi), the standard deviation of the NN interval (SDNN), and the square root of the mean squared differences of successive NN intervals (RMSSD) between the groups. The weaning failure group had a significant increase in LF (41 vs. 69.4) and LF/HF ratio (0.685 vs. 2.6) and a significant decrease in HF (58.85 vs. 30.2). CONCLUSIONS: HRV measure with spectral analysis can be a good predictor of MV weaning failure. Integrating this assessment tool in ICU to predict weaning outcomes could provide more precise prognoses and more adequate assistance quality.

Autonomic dysfunction in COVID-19 patients receiving mechanical ventilation: A cross-sectional study

ABSTRACT BACKGROUND: Coronavirus disease 2019 (COVID-19) can damage cardiac tissue by increasing troponin levels and inducing arrhythmias, myocarditis, and acute coronary syndrome. OBJECTIVES: To analyze the impact of COVID-19 on cardiac autonomic control in mechanically ventilated intensive care unit (ICU) patients. DESIGN AND SETTING: This cross-sectional analytical study of ICU patients of both sexes receiving mechanical ventilation was conducted in a tertiary hospital. METHODS: Patients were divided into COVID-19-positive (COVID(+)) and COVID-19-negative (COVID(-)) groups. Clinical data were collected and heart rate variability (HRV) records obtained using a heart rate monitor. RESULTS: The study sample comprised 82 subjects: 36 (44%) in the COVID(-) group (58.3% female; median age, 64.5 years) and 46 (56%) in the COVID(+) group (39.1% females; median age, 57.5 years). The HRV indices were lower than the reference values. An intergroup comparison identified no statistically significant differences in the mean normal-to-normal (NN) interval, standard deviation of the NN interval, or root mean square of successive differences in NN intervals. The COVID(+) group had an increased low frequency (P = 0.05), reduced high frequency (P = 0.045), and increased low frequency/high frequency (LF/HF) ratio (P = 0.048). There was a weak positive correlation between LF/HF and length of stay in the COVID(+) group. CONCLUSION: Patients who received mechanical ventilation had lower overall HRV indices. COVID(+) patients who received mechanical ventilation had lower vagal HRV components. These findings likely indicate clinical applicability, as autonomic control impairments are associated with a greater risk of cardiac death.

Alterações Hematológicas durante um Período de Sete Dias de Internação em Pacientes com Infarto Agudo do Miocárdio / Hematological Changes during Seven Days of Hospitalization in Patients with Acute Myocardial Infarction

Resumo Fundamento O infarto agudo do miocárdio é uma das principais causas de mortalidade em todo o mundo e a formação de placa aterosclerótica é o principal mecanismo fisiopatológico, que resulta em inflamação crônica e induz a maturação eritrocitária, podendo causar aumento no índice de amplitude de distribuição dos glóbulos vermelhos (RDW). Objetivo Avaliar o papel do índice de anisocitose em pacientes com infarto agudo do miocárdio em ambos os tipos de infarto como preditor de gravidade. Métodos Os pacientes foram incluídos no estudo de acordo com os critérios de inclusão e exclusão, seguindo a rotina hospitalar baseada na história clínica e laboratorial. As análises estatísticas foram realizadas de acordo com cada variável. Chegou-se a todas as conclusões considerando o nível de significância de 5%. Resultados Durante o período de acompanhamento, nos 349 pacientes analisados, a taxa de mortalidade esteve associada às variáveis RDW (CV) e RDW (SD). Nos pacientes que foram a óbito, notou-se aumento, conforme demonstrado no modelo multivariado, nos efeitos de um infarto agudo do miocárdio com supradesnivelamento do segmento ST e RDW, ajustado para fatores de confusão (valor-p = 0,03 e 0,04). Em contrapartida, o número total de eritrócitos (valor-p = 0,00) e hemoglobina (valor-p = 0,03) apresentou diminuição durante a internação de pacientes graves. Conclusão O índice de anisocitose foi fator preditivo de mortalidade e pode ser utilizado como indicador de pior prognóstico em pacientes com infarto agudo do miocárdio.

Abstract Background Acute myocardial infarction is a major cause of mortality worldwide, and atherosclerotic plaque formation is the main pathophysiological mechanism, which results in chronic inflammation that induces erythrocyte maturation and may cause an increase in the red cell distribution width (RDW) index. Objective Evaluate the role of the anisocytosis index in patients with acute myocardial infarction in both types of infarctions as a predictor of severity. Methods Patients were included in the study according to the inclusion/exclusion criteria, following the hospital routine based on their clinical and laboratory history. Statistical analyzes were performed according to each variable. All conclusions were drawn considering the significance level of 5%. Results During the follow-up period, in the 349 patients analyzed, the mortality rate was associated with the variables RDW (CV) and RDW (SD), in those patients who died, an increase was noted, as demonstrated in the multivariate model, for the effects of an acute ST elevation myocardial infarction and the RDW, adjusted for confounding factors (p-value = 0.03 and 0.04). In contrast, the total number of erythrocytes (p-value = 0.00) and hemoglobin (p-value = 0.03) showed a decrease during severe patients' hospitalization. Conclusion The anisocytosis index was a predictive factor of mortality and can be used as an indicator of worse prognosis in patients with acute myocardial infarction.

Heart rate turbulence assessed through ergometry after myocardial infarction: a feasibility study

ABSTRACT BACKGROUND: Coronary artery disease is an important cause of morbidity and mortality. The impact of ventricular arrhythmias with impaired cardiac vagal activity is one of the most recently studied prognostic factors. However, there are no studies evaluating the phenomenon of heart rate turbulence (HRT) during physical exertion. OBJECTIVE: To study the behavior of HRT during exercise testing, among individuals after myocardial infarction. DESIGN AND SETTING: Feasibility study conducted in a university hospital among individuals 4-6 weeks after myocardial infarction. METHODS: All subjects underwent 24-hour Holter monitoring and ergometric stress testing. We considered that abnormal HRT was present if the turbulence onset was ≥ 0% or turbulence slope was ≤ 2.5 mm/relative risk interval. RESULTS: All 32 subjects were asymptomatic. Their median age was 58 years (interquartile range 12.8) and 70% were male. Abnormal HRT was associated with ventricular dysfunction in this population. We found no differences regarding the behavior of HRT, in relation to age, gender, smoking, systemic arterial hypertension, diabetes mellitus or dyslipidemia. Ergometric stress testing detected premature ventricular beats (PVB) in approximately 44% of the examinations, and these occurred both during the active phase of effort and in the recovery period. The low occurrence of several isolated PVB in beta-blocked subjects made it difficult to perform statistical analysis to correlate HRT between ergometric and Holter testing. CONCLUSION: The data obtained in this study do not support performing HRT through ergometric stress testing among patients who remain on beta-blockers post-myocardial infarction, for the purpose of assessing cardiac vagal activity.

Heart rate turbulence assessed through ergometry after myocardial infarction: a feasibility study.

BACKGROUND: Coronary artery disease is an important cause of morbidity and mortality. The impact of ventricular arrhythmias with impaired cardiac vagal activity is one of the most recently studied prognostic factors. However, there are no studies evaluating the phenomenon of heart rate turbulence (HRT) during physical exertion. OBJECTIVE: To study the behavior of HRT during exercise testing, among individuals after myocardial infarction. DESIGN AND SETTING: Feasibility study conducted in a university hospital among individuals 4-6 weeks after myocardial infarction. METHODS: All subjects underwent 24-hour Holter monitoring and ergometric stress testing. We considered that abnormal HRT was present if the turbulence onset was ≥ 0% or turbulence slope was ≤ 2.5 mm/relative risk interval. RESULTS: All 32 subjects were asymptomatic. Their median age was 58 years (interquartile range 12.8) and 70% were male. Abnormal HRT was associated with ventricular dysfunction in this population. We found no differences regarding the behavior of HRT, in relation to age, gender, smoking, systemic arterial hypertension, diabetes mellitus or dyslipidemia. Ergometric stress testing detected premature ventricular beats (PVB) in approximately 44% of the examinations, and these occurred both during the active phase of effort and in the recovery period. The low occurrence of several isolated PVB in beta-blocked subjects made it difficult to perform statistical analysis to correlate HRT between ergometric and Holter testing. CONCLUSION: The data obtained in this study do not support performing HRT through ergometric stress testing among patients who remain on beta-blockers post-myocardial infarction, for the purpose of assessing cardiac vagal activity.

Orthostatic changes in blood pressure and survival in elderly cardiopaths.

OBJECTIVE: The objective of this study was to analyze the association between orthostatic changes in blood pressure and mortality in elderly cardiopath patients. METHODS: A cohort of 455 elderly cardiopath patients, monitored at a referral outpatient cardiology clinic in Pernambuco, Brazil, from October 2015 to July 2018. The exposure groups were formed according to their orthostatic changes in blood pressure following the requirements of the Brazilian Guidelines for Hypertension. RESULTS: Orthostatic hypotension was present in 46 patients (10.1%), 91 had orthostatic hypertension (20%), and 318 had no orthostatic alterations (69.9%). There were 52 deaths during follow-up. The results demonstrated that there was no statistically significant association between orthostatic hypotension and overall mortality (HR 1.30; 95%CI 0.53-3.14; p=0.567) nor between orthostatic hypertension and overall mortality (HR 0.95; 95%CI 0.65-1.39; p=0.34). Survival in relation to the exposure groups presented no statistically significant difference (p=0.504). CONCLUSION: There was a low frequency of orthostatic hypotension and a mild high frequency of orthostatic hypertension when compared with previous studies, and no association was observed with overall mortality or with the survival time of elderly patients with heart disease.

Contributions of the heart rate turbulence method to risk stratification in patients after myocardial infarction: a review.

Coronary artery disease remains an important cause of morbidity and mortality worldwide. The impact of ventricular arrhythmias and impaired cardiac vagal activity on coronary events is one of the most relevant prognostic factors, despite little research being conducted in clinical practice. A simple and cost-effective way to analyze cardiac autonomic regulation is through the heart rate turbulence (HRT) method. Studies have shown that altered HRT, which indicates reduction in the vagal cardiac activity, can identify patients who are at a higher risk of sudden death. Thus, aspects related to the definition, pathophysiological mechanism, conditions that alter the HRT behavior, and the main studies that analyzed the prognostic importance of HRT in patients with ischemic disease were discussed in this review. HRT analysis was proven to be a simple and cost-effective way to assess cardiac autonomic dysfunction by providing complementary information to classic parameters, such as the assessment of ventricular function.

Orthostatic changes in blood pressure and survival in elderly cardiopaths

SUMMARY OBJECTIVE: The objective of this study was to analyze the association between orthostatic changes in blood pressure and mortality in elderly cardiopath patients. METHODS: A cohort of 455 elderly cardiopath patients, monitored at a referral outpatient cardiology clinic in Pernambuco, Brazil, from October 2015 to July 2018. The exposure groups were formed according to their orthostatic changes in blood pressure following the requirements of the Brazilian Guidelines for Hypertension. RESULTS: Orthostatic hypotension was present in 46 patients (10.1%), 91 had orthostatic hypertension (20%), and 318 had no orthostatic alterations (69.9%). There were 52 deaths during follow-up. The results demonstrated that there was no statistically significant association between orthostatic hypotension and overall mortality (HR 1.30; 95%CI 0.53-3.14; p=0.567) nor between orthostatic hypertension and overall mortality (HR 0.95; 95%CI 0.65-1.39; p=0.34). Survival in relation to the exposure groups presented no statistically significant difference (p=0.504). CONCLUSION: There was a low frequency of orthostatic hypotension and a mild high frequency of orthostatic hypertension when compared with previous studies, and no association was observed with overall mortality or with the survival time of elderly patients with heart disease.

Triggering receptor expressed on myeloid cells-1 as pediatric sepsis biomarker.

OBJECTIVE: Triggering receptor expressed on myeloid cells-1 concentration can be used as a predictive, diagnostic, and prognostic marker in patients with sepsis. The objective of this study was to determine the validity of triggering receptor expressed on myeloid cells-1 levels as a biomarker of sepsis in pediatric patients. METHODS: This was an integrative literature review. PubMed, ScienceDirect, LILACS, MEDLINE, and VHL databases were searched for papers published between 2015 and 2020, using the keywords triggering receptor expressed on myeloid cells-1, sepsis, and child. RESULTS: The review included ten studies, of which four used triggering receptor expressed on myeloid cells-1 as a predictive biomarker; four, as a diagnostic biomarker; and two, as a prognostic biomarker. A total of 1,409 and 1,628 patients were included in primary and review studies, respectively. There was a predominance of significant results for the validity of triggering receptor expressed on myeloid cells-1 levels in the prediction, diagnosis, and prognosis of sepsis in pediatric patients. CONCLUSIONS: Triggering receptor expressed on myeloid cells-1 is a valid predictive, diagnostic, and prognostic biomarker of sepsis with good sensitivity and specificity in the pediatric population.