Abstract Background Heart rate (HR) has shown prognostic value in patients with heart failure with reduced ejection fraction (HFrEF) and sinus rhythm. However, the method of measurement is debated in the literature. Objectives To compare HR on Holter with 3 resting electrocardiograms (ECG1, ECG2, and ECG3) in patients with HFrEF and sinus rhythm. Methods This was a cross-sectional study with 135 patients with heart failure with ejection fraction ≤ 40% and sinus rhythm. HR was assessed by ECG and Holter. Analyses included intraclass correlation coefficient (ICC), robust regression, root mean squared error, Bland-Altman, and area under the receiver operating characteristic (ROC) curve. A significance level of 0.05 and Bonferroni-Holm adjustment were adopted to minimize type I errors. Results The median [interquartile range] age and ejection fraction were 65 years [16] and 30% [11], respectively. The ICC of the 3 ECGs was 0.922 (95% confidence interval: 0.892; 0.942). The robust regression coefficients for ECG1 and ECG3 were 0.20 (95% confidence interval: 0.12; 0.29) and 0.21 (95% confidence interval: 0.06; 0.36). The robust R2 was 0.711 (95% confidence interval: 0.628; 0.76). In the Bland-Altman agreement analysis, the limits of agreement were −17.0 (95% confidence interval: −19.0; −15.0) and 32.0 (95% confidence interval: 30.0; 34.0). The area under the ROC curve was 0.896 (95% confidence interval: 0.865; 0.923). Conclusion The HR on ECG showed high agreement with the HR on Holter, validating its clinical use in patients with HFrEF and sinus rhythm. However, agreement was suboptimal in one third of patients with HR below 70 bpm on ECG; thus, 24-hour Holter monitoring should be considered in this context. (HR (HFrEF rhythm However literature ECG1, (ECG1 ECG2 crosssectional cross sectional 13 40 ICC, , (ICC) error BlandAltman, BlandAltman Bland Altman, Altman (ROC 005 0 05 0.0 BonferroniHolm Bonferroni Holm errors interquartile range 6 16 [16 30 11, 11 [11] respectively 0922 922 0.92 95% 95 (95 interval 0.892 0892 892 0.942. 0942 0.942 . 942 0.942) 020 20 0.2 0.12 012 12 0.29 029 29 021 21 0.06 006 06 0.36. 036 0.36 36 0.36) R 0711 711 0.71 0.628 0628 628 0.76. 076 0.76 76 0.76) analysis 170 17 −17. −19.0 190 19 −15.0 150 15 320 32 32. 30.0 300 34.0. 340 34.0 34 34.0) 0896 896 0.89 0.865 0865 865 0.923. 0923 0.923 923 0.923) 7 thus 24hour hour 24 context (ECG 1 4 (ICC 00 0. [1 [11 092 92 0.9 9 (9 089 89 094 0.94 94 02 2 0.1 01 03 0.3 071 71 0.7 0.62 062 62 07 −17 −19. −15. 30. 34. 0.8 0.86 086 86 [ 09 ( 08 8 0.6 −1 −19 −15 −

Resumo Fundamento A frequência cardíaca (FC) na insuficiência cardíaca com fração de ejeção reduzida (ICFEr) e ritmo sinusal apresenta valor prognóstico. Entretanto, o método de mensuração é debatido na literatura. Objetivos Comparar em pacientes com ICFEr e ritmo sinusal a FC no Holter com três eletrocardiogramas de repouso: ECG1, ECG2 e ECG3. Metodologia Estudo transversal com 135 pacientes portadores de insuficiência cardíaca com fração de ejeção ≤ 40% e ritmo sinusal. A FC foi avaliada por ECG e Holter. Análises incluíram o coeficiente de correlação intraclasse (CCI), regressão robusta, raiz do erro quadrático médio, Bland-Altman e a área sobre a curva ROC. Adotou-se nível de significância de 0,05 e o ajuste de Bonferroni-Holm para minimizar erros tipo I. Resultados As medianas [intervalo interquartil] de idade e fração de ejeção foram de 65 anos [16] e 30% [11], respectivamente. O CCI dos 3 ECG foi de 0,922 (intervalo de confiança de 95%: 0,892; 0,942). Os coeficientes de regressão robusta para ECG1 e ECG3 foram 0,20 (intervalo de confiança de 95%: 0,12; 0,29) e 0,21 (intervalo de confiança de 95%: 0,06; 0,36). O R2 robusto foi de 0,711 (intervalo de confiança de 95%: 0,628; 0,76). Na análise de concordância de Bland-Altman, os limites de concordância foram de −17,0 (intervalo de confiança de 95%: −19,0; −15,0) e 32,0 (intervalo de confiança de 95%: 30,0; 34,0). A área sob a curva ROC foi de 0,896 (intervalo de confiança de 95%: 0,865; 0,923). Conclusão A FC do ECG mostrou alta concordância com a FC do Holter, validando seu uso clínico em pacientes com ICFEr e ritmo sinusal. Contudo, a concordância foi subótima em um terço dos pacientes com FC inferior a 70 bpm pelo ECG, devendo ser considerada a realização de Holter neste contexto. (FC (ICFEr prognóstico Entretanto literatura repouso 13 40 CCI, , (CCI) médio BlandAltman Bland Altman Adotouse Adotou se 005 0 05 0,0 BonferroniHolm Bonferroni Holm I intervalo interquartil 6 16 [16 30 11, 11 [11] respectivamente 0922 922 0,92 95% 95 0,892 0892 892 0,942. 0942 0,942 . 942 0,942) 020 20 0,2 0,12 012 12 0,29 029 29 021 21 0,06 006 06 0,36. 036 0,36 36 0,36) R 0711 711 0,71 0,628 0628 628 0,76. 076 0,76 76 0,76) BlandAltman, Altman, 170 17 −17, −19,0 190 19 −15,0 150 15 320 32 32, 30,0 300 34,0. 340 34,0 34 34,0) 0896 896 0,89 0,865 0865 865 0,923. 0923 0,923 923 0,923) Contudo 7 contexto 1 4 (CCI 00 0, [1 [11 092 92 0,9 9 089 89 094 0,94 94 02 2 0,1 01 03 0,3 071 71 0,7 0,62 062 62 07 −17 −19, −15, 30, 34, 0,8 0,86 086 86 [ 09 08 8 0,6 −1 −19 −15 −

Objective: To investigate the association between attention-deficit/hyperactivity disorder (ADHD) symptoms and entrepreneurial profiles and the effects of entrepreneurial characteristics in individuals who screen positive for ADHD and self-identify as entrepreneurs. Methods: We sent 4,341 questionnaires by e-mail to applicants for a career development course for entrepreneurs. We used the propensity score covariate adjustment to balance differences between included and excluded individuals. ADHD symptoms were evaluated with the Adult ADHD Self-Report Scale. The Individual Entrepreneurial Orientation scale was used to assess the entrepreneurial profile of the participants. Impairment from ADHD symptoms was assessed with the Barkley Functional Impairment Scale. Results: Those who screened positive for ADHD had higher risk-taking scores (p-value = 0.016) and lower proactivity (p-value = 0.001) than those who screened negative. Higher inattention scores were related to lower proactivity (p-value < 0.001), while higher hyperactive symptom scores were related to a more generalized entrepreneurial profile (p-value = 0.033). Among ADHD-positive participants, entrepreneurial profile scores were not significantly associated with company profits or impairment. Conclusions: Inattention symptoms were related to less proactivity, whereas hyperactive symptoms were positively associated with a general entrepreneurial orientation. ADHD-positive individuals had a higher risk-taking profile, and these characteristics did not negatively impact their lives. Objective attentiondeficit/hyperactivity attentiondeficithyperactivity attention deficit/hyperactivity deficit hyperactivity (ADHD selfidentify self identify entrepreneurs Methods 4341 4 341 4,34 email e mail SelfReport Self Report Scale participants Results risktaking risk taking pvalue p value 0.016 0016 0 016 0.001 0001 001 negative 0.001, , 0.033. 0033 0.033 . 033 0.033) ADHDpositive impairment Conclusions orientation lives attentiondeficit deficithyperactivity 434 34 4,3 0.01 01 0.00 000 00 003 0.03 03 43 3 4, 0.0 0.