harada masahide

Background: We aimed to investigate the association between ventricular repolarization instability and sustained ventricular tachycardia and ventricular fibrillation (VT/VF) occurring within 48 h (acute-phase VT/VF) after the onset of acute coronary syndrome (ACS) and the prognostic role of repolarization instability and heart rate variability (HRV) after discharge from the hospital. Methods: We studied 572 ACS patients with a left ventricular ejection fraction >35%. The ventricular repolarization instability was assessed by the beat-to-beat T-wave amplitude variability (TAV) using high-resolution 24-h Holter ECGs recorded at a median of 11 days from the date of admission. We calculated the HRV parameters including the deceleration capacity (DC) and non-Gaussian index calculated on a 25 s timescale (λ25s). The DC and λ25s were dichotomized based on previous studies' thresholds. Results: Acute-phase VT/VF developed in 43 (7.5%) patients. In-hospital mortality was significantly higher among VT/VF patients (4.7% vs. 0.9%, p =.03). An adjusted logistic model showed that the maximum TAV (odds ratio 1.02, 95% confidence interval [CI] 1.00–1.29, p =.04) was associated with acute-phase VT/VF. During a median follow-up period of 2.1 years, 19 (3.3%) patients had cardiac deaths or resuscitated cardiac arrest. Acute-phase VT/VF (p =.12) and TAV (p =.72) were not significant predictors of survival. An age and sex-adjusted Cox model showed that the DC (p <.01), λ25s (p <.01), and emergency coronary intervention (p <.01) were independent predictors. Conclusion: T-wave amplitude variability was associated with acute-phase VT/VF, but the TAV was not predictive of survival post-discharge. The DC, λ25s, and emergency coronary intervention were independent predictors of survival.

BACKGROUND: Circulating microRNAs (miRNAs, miR) have been considered as biomarkers reflecting the underlying pathophysiology in atrial fibrillation (AF). Nevertheless, miRNA expression in the peripheral blood samples might not reflect a cardiac phenomenon since most miRNAs are expressed in numerous organs. This study aimed to identify the cardiac-specific circulating miRNAs as biomarkers for AF. METHODS: Plasma samples were obtained from a luminal coronary sinus catheter (CS, cardiac-specific samples) and femoral venous sheath (FV, peripheral samples) in patients with AF and paroxysmal supraventricular tachycardia (control, CTL) undergoing catheter ablation. The circulating miRNA profiles were analyzed by small RNA sequencing. Differently expressed miRNAs between AF and CTL were identified in each sample of the CS and FV; miRNAs exhibiting similar expression patterns in the CS and FV samples were selected as candidates for cardiac-specific biomarkers. The selected miRNAs were related to the outcome of catheter ablation of AF. RESULTS: Small RNA sequencing detected 849 miRNAs. Among the top 30 most differently expressed miRNAs between AF and CTL, circulating hsa-miR-20b-5p, hsa-miR-330-3p, and hsa-miR-204-5p had a similar pattern in the CS and FV samples. Another set of peripheral blood samples was obtained from AF patients undergoing catheter ablation (n = 141). The expression of the miR-20b-5p and miR-330-3p, but not the miR-204-5p, negatively correlated with the echocardiographic left-atrial dimension and was decreased in patients with AF recurrence as compared to those without AF recurrence during a 1-year follow-up. CONCLUSION: Circulating miR-20b-5p and miR-330-3p can be cardiac-specific biomarkers for atrial remodeling progression and arrhythmia recurrence after catheter ablation in AF patients.