Partial left superior pulmonary vein potential elimination by an inferior ganglionated plexus ablation.

Ganglionated plexus (GP) plays an important role in the initiation and maintenance of atrial fibrillation (AF). The GP ablation has been found to be effective for AF treatment. In this case, we reported an AF case in which the pulmonary vein (PV) potentials of the anterior region of the left superior PV were eliminated by an inferior right GP ablation.

Atrial electrical abnormality in patients with Brugada syndrome assessed by signal-averaged electrocardiography.

BACKGROUND: Ventricular fibrillation and atrial fibrillation are well-known arrhythmias in patients with Brugada syndrome. This study evaluated the characteristics of the atrial arrhythmogenic substrate using the signal-averaged electrogram (SAECG) in patients with Brugada syndrome. METHODS: SAECGs were performed during normal sinus rhythm in 23 normal volunteers (control group), 21 patients with paroxysmal atrial fibrillation (PAF; PAF group), and 21 with Brugada syndrome (Brugada group). RESULTS: The filtered P wave duration (fPd) in the control, Brugada, and PAF groups was 113.9±12.9ms, 125.3±15.0ms, and 137.1±16.3ms, respectively. The fPd in the PAF group was significantly longer compared to that in the control and Brugada groups (p<0.05). The fPd in the Brugada group was significantly longer than that in the control group (p<0.05) and significantly shorter than that in the PAF group (p<0.05). CONCLUSION: Patients with Brugada syndrome had abnormal P waves on the SAECG. The abnormal P waves on the SAECG in Brugada syndrome patients may have intermediate characteristics between control and PAF patients.

Update of Japanese common LDLR gene mutations and their phenotypes: Mild type mutation L547V might predominate in the Japanese population.

We investigated the LDLR gene mutations in 205 unrelated Japanese FH (familial hypercholesterolemia) heterozygotes to see if there is a prevalence of common mutations in the Japanese population. A total of 53 different small mutations (<25bp) and 10 kinds of large deletions (>25bp) were identified. Among them there were eight relatively frequent mutations: C317S, c.1845+2T>C, K790X, L547V, P664L, D412H, c.2312-3C>A and V776M. The patients with these mutations comprised 32% of the total FH heterozygotes investigated. Comparison of clinical phenotypes of the eight frequent mutations disclosed that a missense mutation, L547V, manifested a milder phenotype than the other mutations. The mild clinical phenotype was shown to be based on the high level of receptor activity remaining on the patient's cell surfaces. When we examined the presence of common mutations in a general population, the L547V mutation was detected with unexpectedly higher frequency than the other mutations, suggesting an underestimation of the frequency of this mutation in FH heterozygote patients. In conclusion, although there is a broad spectrum of LDLR gene mutations in the Japanese population, eight common mutations were observed. Among them, a mild phenotype mutation, L547V, might predominate in the Japanese population.

Genetic variants in PCSK9 in the Japanese population: rare genetic variants in PCSK9 might collectively contribute to plasma LDL cholesterol levels in the general population.

The aim of this study was to investigate whether plasma low-density lipoprotein cholesterol (LDL-C) levels in the general population are influenced by rare sequence variations in the PCSK9 gene. We sequenced the promoter and coding regions of the PCSK9 gene in individuals from the general population (n=3655) with the lowest (n=78) and highest (n=96) LDL-C levels and in individuals taking antihypercholesterolemia medication (n=96). We identified 33 sequence variants in the PCSK9 gene among which 24 were specific for Japanese. Statistical analysis showed that one missense mutation, R93C, was associated with low LDL-C levels. The other variants had no association with LDL-C levels or the numbers of individuals with the variants were too small for statistical analysis. A comparison of the numbers of individuals with nonsynonymous mutations between the low LDL-C and high LDL-C/treatment groups found that four missense mutations and one nonsense mutation were identified only in the low LDL-C group and six missense mutations were identified only in the high LDL-C/treatment group. As we have analyzed groups at opposite ends of the LDL-C spectrum, it is likely that some of these nonsynonymous mutations may be associated with either low or high LDL-C in the Japanese population. Based on the extremely high frequencies of the nonsynonymous mutations in PCSK9 compared with those of LDLR or apoB-100, PCSK9 mutations could be important factors that cumulatively influence plasma LDL-C levels in the general population.