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Mutations in cardiac potassium and sodium channel genes are responsible for several hereditary cardiac arrhythmia syndromes. We established a denaturing high-performance liquid chromatography (DHPLC) protocol for rapid mutation screening of these genes, and reported mutations and variations identified by this method. We included 28 patients with Brugada syndrome, 4 with congenital long QT syndrome (LQTS), 11 with drug-induced LQTS, 4 with idiopathic ventricular fibrillation, and 50 normal volunteers. Polymerase chain reactions were performed to amplify the entire coding region of these genes. DHPLC was used to screen for heteroduplexes then DNA sequencing was performed. With this method, we identified the mutation(s) in all four patients with congenital LQTS ( KCNQ1 A341V, KCNH2 N633D, KCNH2 2768Cdel and KCNE1 K70 N Y81C double mutations). We also identified the SCN5A A551T mutation in 1 of the 28 patients with Brugada syndrome. All the above-mentioned mutations were novel except KCNQ1 A341V. No mutations were identified in patients with drug-induced LQTS or idiopathic ventricular fibrillation. In total, 25 single nucleotide polymorphisms were identified, 10 of which were novel. In conclusion, DHPLC is a sensitive and rapid method for detection of cardiac sodium and potassium channel gene mutations. [ABSTRACT FROM AUTHOR]

Background and objective: Hypertension is very prevalent in the Chinese population in Taiwan. Chinese people frequently experience bothersome cough when receiving angiotensin-converting enzyme (ACE) inhibitors, and angiotensin II (AT1) receptor antagonists are thus relatively more frequently used in this context. In this trial we studied the effectiveness of a new AT1 receptor antagonist, olmesartan, in the treatment of Chinese patients with mild-to-moderate essential hypertension. Patients and methods: The present study was a double-blind, randomised, multicentre trial to compare the efficacy and safety profiles of two AT1 receptor antagonists, olmesartan and losartan, in the treatment of Chinese patients with mild-to-moderate essential hypertension. 126 adults were randomised to receive either once-daily olmesartan 20mg or once-daily losartan 50mg for 12 weeks. There were 49 evaluable patients in the olmesartan group and 57 in the losartan group. Results: At baseline, neither diastolic (DBP) nor systolic (SBP) blood pressures were significantly different between the two study groups. Trough blood pressures were measured and recorded for the evaluation of treatment effect. After drug treatment for 4, 8 and 12 weeks, SBP and DBP values were significantly decreased in both groups of patients. However, both SBP and DBP were significantly lower in the olmesartan group than in the losartan group after treatment. At the end of treatment, DBP values were 87.0 ± 8.6mm Hg versus 91.6 ± 8.7mm Hg (p < 0.001) and SBP values were 129.5 ± 12.6mm Hg versus 135.4 ± 12.1mm Hg (p < 0.001) in the olmesartan and losartan groups, respectively. After 4 weeks of treatment, the reduction in BP values was larger in the olmesartan group than in the losartan group (decreases in DBP of 12.1 ± 8.4mm Hg vs 7.2 ± 6.8mm Hg [p < 0.005] and in SBP of 15.1 ± 13.0mm Hg vs 10.3 ± 10.1mm Hg [p < 0.05] for the olmesartan and losartan groups, respectively). Patients treated with either drug experienced only mild adverse reactions, such as dizziness, cough, headache and neck pain, all of which occurred at low frequencies. There were no significant changes in laboratory parameters. Conclusion: Both olmesartan and losartan are effective and safe in the treatment of Chinese patients with mild-to-moderate essential hypertension. Olmesartan 20mg once daily is more potent and has a more rapid antihypertensive effect than losartan 50mg once daily in the treatment of mild-to-moderate hypertension in Chinese patients. [ABSTRACT FROM AUTHOR]

A correction to the article "Denaturing high-performance liquid chromatography screening of the long QT syndrome-related cardiac sodium and potassium channel genes and identification of novel mutations and single nucleotide polymorphisms," is presented.