Hypertension is one of the most important risk factors associated with atrial fibrillation (AF) and increased the risk of cardiovascular events in patients with AF. However, the pathophysiological link between hypertension and AF is unclear. Nevertheless, this can be explained by the hemodynamic changes of the left atrium secondary to long standing hypertension, resulting in elevated left atrium pressure and subsequently left atrial enlargement. Moreover, the activation of renin --angiotensin --aldosterone system (RAAS) activation in patients with hypertension induces left atrial fibrosis and conduction block in the left atrium, resulting in the development of AF. Accordingly, recent studies have shown that effective blockage of RAAS by angiotensin converting enzyme inhibitors or angiotensin receptor antagonist may be effective in both primary and secondary prevention of AF in patients with hypertension, although with controversies. In addition, optimal antithrombotic therapy, blood pressure control as well as rate control for AF are key to the management of patients with AF. 1,2 Both hypertension 3 and AF 4 have increased frequency with the ageing population worldwide, and are associated with increased cardiovascular events. They are important risk factors for stroke, heart failure and overall mortality. 5 --7 On the other hand, hypertension is one of the important risk factors for the occurrence of AF, 8 and increased the risk of stroke and cardiovascular mortality in patients with AF.9,10 Compare with other risk factors for AF, hypertension appears to be responsible for more AF than any other risk factor because of its high prevalence. However, the pathophysiological link between AF and hypertension remains unclear. Moreover, it is also unclear whether treatment of hypertension prevents AF or reduces the risk of AF related complications. The purpose of this article is to review the epidemiology, underlying mechanisms and therapeutic implications of AF in hypertensive patients. A systematic literature search for full-text papers in the English language was performed using MEDLINE, Embase and the Cochrane library through to July 2011. In the search phrases used, the following terms were used: 'atrial fibrillation', 'hypertension', 'epidemiology', 'pathophysiology' and 'treatment'. Papers selected and cited in this review were based on the authors' view on the relevance to the manuscript. In addition, abstracts from international cardiovascular meetings were studied to identify unpublished studies.

In situ hybridization with a cloned human Y-specific repeat, pY3.4, derived from the 3.4-kb HaeIII repetitive sequences, is useful in identifying Yq-autosome translocations. In this study nonradioactive procedures were also employed to detect the sites of hybridization. Using a biotinylated probe and either immunofluorescence or horseradish peroxidase reaction, the chromosomes of three probands and members of their families with probable Y-autosome translocations were examined. It was found that not all such translocations can be correctly diagnosed based on conventional banding analysis. The present data indicate the importance of chromosome-specific probes in studying chromosome rearrangements in man.

Cytological analysis of a squirrel monkey indicates a considerable degree of chromosomal polymorphism. DNA synthetic patterns reveal late synthesis in chromosomal segments that are C-band negative and asynchrony in DNA replication between homologs. Location of a satellite DNA with a CsCl neutral buoyant density of 1.691 g/ml was mainly in the noncentromeric constitutive heterochromatin.