Heart rate variability in critical care medicine: a systematic review

Abstract

BackgroundHeart rate variability (HRV) has been used to assess cardiac autonomic activity in critically ill patients, driven by translational and biomarker research agendas. Several clinical and technical factors can interfere with the measurement and/or interpretation of HRV. We systematically evaluated how HRV parameters are acquired/processed in critical care medicine.MethodsPubMed, MEDLINE, EMBASE and the Cochrane Central Register of Controlled Trials (1996–2016) were searched for cohort or case–control clinical studies of adult (>18 years) critically ill patients using heart variability analysis. Duplicate independent review and data abstraction. Study quality was assessed using two independent approaches: Newcastle–Ottowa scale and Downs and Black instrument. Conduct of studies was assessed in three categories: (1) study design and objectives, (2) procedures for measurement, processing and reporting of HRV, and (3) reporting of relevant confounding factors.ResultsOur search identified 31/271 eligible studies that enrolled 2090 critically ill patients. A minority of studies (15; 48%) reported both frequency and time domain HRV data, with non-normally distributed, wide ranges of values that were indistinguishable from other (non-critically ill) disease states. Significant heterogeneity in HRV measurement protocols was observed between studies; lack of adjustment for various confounders known to affect cardiac autonomic regulation was common. Comparator groups were often omitted (n = 12; 39%). This precluded meaningful meta-analysis.ConclusionsMarked differences in methodology prevent meaningful comparisons of HRV parameters between studies. A standardised set of consensus criteria relevant to critical care medicine are required to exploit advances in translational autonomic physiology.Electronic supplementary materialThe online version of this article (doi:10.1186/s40635-017-0146-1) contains supplementary material, which is available to authorized users.

Metabolic myocardial disorders in children with bronchial asthma

“…Results similar to our results were obtained by S. N. Karmali et al [13], who concluded that a single dose of β 2 -agonist increased the heart rate by 9.12 beats/min and reduced the potassium concentration by 0.36 mmol/L, compared to placebo. For trials lasting from 3 days to 1 year, β 2 -agonist treatment significantly increased the risk for a cardiovascular event (relative risk [RR], 2.54; 95 % CI, 1.59 to 4.05) compared to placebo.…”

Use of photoplethysmography to predict mortality in intensive care units

“…In ICUs, the major studies have focused on the use of HRV for the prediction of morbimortality. 35 It is traditionally obtained by comparing the R–R intervals in the electrocardiogram, differently from this study, which used the interval between the PPG SPs. Studies have shown that the analysis of the HRV is reliable in individuals at rest and that motion artifacts can contaminate the signal.…”

“… 38 The results did not present a significant difference between the groups, as it was expected and shown in other studies, in which a lower HRV is related to a higher sympathovagal imbalance and higher mortality. 35 Perhaps, the very short time in collecting data has influenced such results.…”

Análise da variabilidade da frequência cardíaca como preditora de falha/sucesso da extubação traqueal em pediatria

“…As alterações cardiovasculares podem ser avaliadas de diversas formas, dentre elas, por meio da análise da VFC. O estudo da VFC é um método não invasivo e seletivo que avalia a modulação autonômica102,103 . HF= 0,15-1,2Hz), correspondendo à modulação vaga46 .…”

“…Este fator talvez possa ter contribuído para que a VFC não tenha apresentado significância estatística como preditora da falha/sucesso do processo de desmame ventilatório, do TRE e da extubação traqueal. A ausência de estudos prévios em pediatria com número de amostra maior e com análise de subgrupos por doenças/fisiopatologias específicas, dificultam as comparações do comportamento no processo de desmame ventilatório nesta faixa etária46,103 .Em geral, os estudos são baseados em registros de curto prazo da VFC e envolvem grupos heterogêneos com resultados divergentes46,103 . do CO2 exalado devem ser rotina das Unidades de Terapia Intensiva Pediátrica, haja visto que se trata de uma medida não invasiva, de fácil aplicação frente à equipe multiprofissional e que traz informações importantes do paciente pediátrico, como maior risco de falha/ sucesso da extubação traqueal.As limitações econtradas no nosso estudo foram o N pequeno (apenas 43 TRE), além de grupo de pacientes heterogêneo, mesmo quando avaliados apenas o subgrupo de "doenças respiratórias".…”