shows the clinical characteristics, the detection of mtDNA4977, and the amount of mtDNA4977 in the study patients. The mtDNA4977 was not detected in all 22 pediatric/adolescent patients, and none of the pediatric/adolescent patients had AF. In the adult group, 26 patients had AF while 40 patients did not. Patients with AF had a significantly higher incidence of valvular heart disease, lower incidence of coronary artery disease, and a higher left atrial filling pressure. Patients with AF had a higher incidence for detecting mtDNA4977 and a larger amount of mtDNA4977 than patients without AF, while the age was not significantly different between patients with or without AF. Among the 66 adult patients, 52 patients had mtDNA4977 and 14 patients did not (Table 3
). The two groups did not differ significantly in the right atrial filling pressure, left atrial filling pressure, left atrial dimension, gender distribution, system hypertension, and cardiac diagnosis (having valvular heart disease or not and having coronary artery disease or not). However, the two groups differed significantly in age and clinical AF. The mean age was significantly higher in patients with mtDNA4977 than in patients without mtDNA4977 (56.8 ± 14.5 years vs 46.8 ± 20.3 years, p < 0.039) [mean ± SD]. Patients with mtDNA4977 also had a higher incidence of AF (46.2% vs 14.3%, p < 0.032) as well as a higher AF score (1.15 ± 1.36 vs 0.36 ± 0.93, p < 0.016).