The effect of idiopathic premature ventricular complexes on left ventricular ejection fraction.

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.

Could decreased vitamin D levels be related with impaired cardiac autonomic functions in patients with chronic heart failure: an observational study.

OBJECTIVE: Vitamin D status has been implicated in the pathophysiology of heart failure (HF). The aim of this study was to investigate the association between vitamin D levels with heart rate variability and heart rate turbulence in patients with heart failure whom had ischemic and non-ischemic dilated cardiomyopathy. METHODS: Study designed as an observational cross-sectional study. Seventy-one patients [36 non-ischemic dilated cardiomyopathy (NIDCM), 35 ischemic dilated cardiomyopathy (IDCM)] with chronic heart failure and 25 control subject were included. It was evaluated the association between 25 hydroxyvitamin D [25(OH)D] and calcitriol levels with heart rate variability time domain (SDNN, SDANN, RMSSD) and heart rate turbulence [turbulence onset (TO), turbulence slope (TS)] parameters. Statistical analysis was performed using Kruskal-Wallis test and ANOVA. RESULTS: Calcitriol levels in NIDCM patients with abnormal TO and TS were significantly lower than NIDCM patients with normal TO (17.1 ± 11.3 vs. 27.6 ± 15.5 pg/mL, p=0.05) and TS (16.6 ± 9.1 vs. 29.4 ± 16.9 pg/mL, p=.018). There was a positive correlation between 25 (OH) D with heart rate variability parameters SDNN (r=0.368, p=0.027) and SDANN (r=0.360, p=0.031). It was not found any association between vitamin D and parameters of heart rate variability and heart rate turbulence in IDCM patients. CONCLUSION: Insufficiency of vitamin D may have deleterious effects on cardiac autonomic functions which were showed with heart rate turbulence and heart rate variability in patients with NIDCM. Vitamin D levels might be a predictor to determine the sudden cardiac death in patients with non-ischemic etiology.