
Keywords: فرکانس بالا; bpm; Beats per minute; ECG; Electrocardiographic; HCN4; Hyperpolarization-activated cyclic nucleotide-gated potassium channel 4; HF; High frequency; HRV; Heart rate variability; LF; Low frequency; N-N; Normal-to-normal; pro-BNP; Pro-brain natriuretic pept