Background: Autonomic dysfunction may occur during the acute phase of COVID‐19. Heart rate variability (HRV) is a useful tool for the assessment of cardiac sympathetic and parasympathetic balance. We aimed to evaluate cardiac autonomic function by using HRV in subjects after recovery from COVID‐19 who had previously symptomatic and were followed outpatiently.Methods: The study group composed of 50 subjects with a confirmed history of COVID‐19 and the control group composed of 50 healthy subjects without a history of COVID‐19 and vaccination. All the study participants underwent 2‐dimensional, pulsed‐ and tissue‐Doppler echocardiographic examinations and 24‐hour Holter monitoring for HRV analysis.Results: Time domain parameters of SDNN, SDANN, SDNNi, RMSSD, pNN50, and HRV triangular index were all decreased in the study group when compared with the control group. Frequency domain parameters of TP, VLF, LF, HF, and HFnu were also decreased in the study group in comparison with the control group. LFnu was similar between groups. Nonlinear parameters of HRV including α₁and α₂decreased in the study group. By contrast, Lmax, Lmean, DET, REC, and Shannon entropy increased in the study population. Approximate and sample entropies also enhanced in the study group.Conclusions: The present study showed that all three domain HRV significantly altered in patients after recovery from COVID‐19 indicating some degree of dysfunction in cardiac autonomic nervous system. HRV may be a useful tool for the detection of preclinical autonomic dysfunction in this group of patients.

Background: Although the pathophysiology of coronary slow flow (CSF) has not been fully elucidated, emerging data increasingly support potential role for subclinical diffuse atherosclerosis in the etiology of CSF. We aimed to investigate relationship between atherogenic indices and CSF. Methods: 130 patients with CSF diagnosed according to Thrombolysis in Myocardial Infarction (TIMI)-frame count (TFC) method and 130 controls who had normal coronary flow (NCF) were included in this retrospective study. Atherogenic indices (atherogenic index of plasma [AIP], Castelli risk indices I and II [CRI-I and II]) were calculated using conventional lipid parameters. Results: The logistic regression analyses demonstrated that AIP (OR, 5.463; 95% confidence interval [CI], 1.357–21.991; p = 0.017) and CRI-II (OR, 1.624; 95% CI, 1.138–2.319; p = 0.008) were independent predictors of CSF. Receiver operating characteristic analysis showed that the optimal cutoff value to predict the occurrence of CSF was 0.66 for AIP (sensitivity, 59%; specificity, 73%; area under curve [AUC], 0.695; p < 0.001) and 3.27 for CRI-II (sensitivity, 60%; specificity, 79%; AUC, 0.726; p < 0.001). Conclusions: AIP and CRI-II levels were independent predictors of CSF. Prospective studies in larger cohorts of patients may elucidate the role of atherogenic dyslipidemia in the pathophysiology of CSF.

Background: Index of cardio-electrophysiological balance (iCEB) has been described as a novel risk marker for predicting malignant ventricular arrhythmia. There remains limited evidence on the effects of amiodarone and propafenone used for sinus rhythm maintenance on iCEB in patients with atrial fibrillation (AF). The aim of this study was to evaluate iCEB in patients with AF on antiarrhythmic-drug therapy. Methods: A total of 108 patients with AF (68 patients using amiodarone and 40 patients using propafenone) and 50 healthy subjects were included in the study. All groups underwent a standard 12-lead surface electrocardiogram. QRS duration, QT, T wave peak-to-end (Tp-e) intervals, iCEB (QT/QRS) and iCEBc (heart rate-corrected QT (QTc)/QRS) rates were calculated from the electrocardiogram and compared between groups. Results: QT, Tp-e intervals and Tp-e/QT ratio were significantly longer in the amiodarone group than the propafenone and control groups (P < 0.001, for all). iCEB was similar in the amiodarone and control groups (4.4 ± 0.6 and 4.2 ± 0.4; P > 0.05), while iCEB values in the propafenone group were significantly lower than the amiodarone group and control groups (3.9 ± 0.5; P < 0.001). There was a significantly difference in iCEBc values among the amiodarone, control and propafenone groups (4.8 ± 0.6, 4.6 ± 0.4 and 4.3 ± 0.6; P < 0.001, respectively). Conclusions: In this study, higher iCEBc parameters were observed in patients using amiodarone, while iCEBc values were lowest among patients with AF using propafenone. Further studies are needed to determine whether these electrophysiological changes are associated with ventricular arrhythmias for patients with AF on antiarrhythmic-drug therapy. Cardiol Res. 2021;12(1):37-46 doi: https://doi.org/10.14740/cr1185

Aim: Current literature lacks a definitive threshold of idiopathic premature ventricular complex (PVC) burden for predicting cardiomyopathy (CMP). The main objective of the present study was to evaluate relationship between the PVC burden and left ventricular ejection fraction (LVEF).Method: This multicenter, cross‐sectional study included 341 consecutive patients with more than 1,000 idiopathic PVC in 24 hr of Holter monitoring admitted to the cardiology clinics between January 2019 and May 2019 in the nineteen different centers. The primary outcome was the LVEF measured during the echocardiographic examination.Result: Overall, the median age was 50 (38–60) and 139 (49.4%) were female. Percentage of median PVC burden was 9% (IQR: 4%–17.4%). Median LVEF was found 60% (55–65). We used proportional odds logistic regression method to examine the relationship between continuous LVEF and candidate predictors. Increase in PVC burden (%) (regression coefficient (RE) −0.644 and 95% CI −1.063, –0.225, p < .001), PVC QRS duration (RE‐0.191 and 95% CI −0.529, 0.148, p = .049), and age (RE‐0.249 and 95% CI −0.442, −0.056, p = .018) were associated with decrease in LVEF. This inverse relationship between the PVC burden and LVEF become more prominent when PVC burden was above 5%. A nomogram developed to estimate the individual risk for decrease in LVEF.Conclusion: Our study showed that increase in PVC burden %, age, and PVC QRS duration were independently associated with decrease in LVEF in patients with idiopathic PVC. Also, inverse relationship between PVC burden and LVEF was observed in lower PVC burden than previously known.

Introduction: Coronavirus disease 2019 (COVID-19) is an inflammatory disease, and serum albumin and fibrinogen are two important factors in systemic inflammation. We aimed to investigate the relationship between the fibrinogen-to-albumin ratio (FAR) and in-hospital mortality in COVID-19 patients admitted to the intensive care unit (ICU). Material and methods: Patients diagnosed with COVID-19 admitted to the Adiyaman Training and Research Hospital from August to November 2020 were enrolled in this retrospective cohort study. They were divided into 2 groups based on in-hospital mortality: a survivor group (n = 188) and a non-survivor group (n = 198). FAR was calculated by dividing the fibrinogen value by the albumin value. Mortality outcomes were followed up until December 15, 2020. Results: The average age of the patients was 71.2 ± 12.9 years, and 54% were male. On multivariate logistic analysis, diabetes mellitus (OR: 1.806; 95% CI: 1.142–2.856; p = 0.011), troponin I levels (OR: 1.776; 95% CI: 1.031–3.061; p = 0.038), and FAR (OR: 1.004; 95% CI: 1.004–1.007; p = 0.010) at ICU admission were independent predictors of in-hospital mortality in patients with COVID-19. Conclusions: The FAR at admission was associated with mortality in patients infected with SARS-CoV-2 in the ICU.

Aim: This study aimed to evaluate the association between admission lactate to albumin ratio (LAR) and in-hospital mortality in critically ill patients hospitalized with acute decompensated heart failure (ADHF).Material sand Methods: This retrospective single-center study included 87 adult patients admitted to a coronary intensive care unit (ICU) with ADHF. LAR was calculated using admission laboratory values. Patients were classified according to in-hospital survival status. Clinical, laboratory, and echocardiographic variables were analyzed to identify predictors of in-hospital mortality. Receiver operating characteristic (ROC) analysis was performed to assess the prognostic performance of the LAR.Results: In-hospital mortality occurred in 29 of 87 patients (33.3%). Median lactate levels were significantly higher in non-survivors compared with survivors (3.47 vs. 2.10 mmol/L, p < 0.001). The LAR was also higher in non-survivors (0.93 vs. 0.59, p = 0.002), while left ventricular ejection fraction (LVEF) was lower (28.2% vs. 36.1%, p = 0.006). In multivariable logistic regression analysis, mechanical ventilation (adjusted OR 80.8, p < 0.001) and LVEF (adjusted OR 0.92 per %, p = 0.016) were independently associated with in-hospital mortality, whereas the LAR was not (p = 0.266). ROC analysis demonstrated fair discrimination for the LAR in predicting mortality (AUC 0.706).Conclusion: Although higher LAR values were associated with mortality in unadjusted analysis, this marker did not provide independent prognostic value beyond established indicators of disease severity in critically ill patients with ADHF.