RT Journal
A1 Oh J, Won H, Kang S
T1 OUtcomes in patients with prolonged pr interval or first-degree atrioventricular block
JF JAMA
JO JAMA
YR 2009
FD November 11
VO 302
IS 18
SP 1967
OP 1968
DO 10.1001/jama.2009.1603
UL http://dx.doi.org/10.1001/jama.2009.1603
AB 
To the Editor: In their cohort study using patients from the Framingham Heart Study, Dr Cheng and colleagues1 found that prolongation of the PR interval or first-degree atrioventricular (AV) block was associated with increased risks of atrial fibrillation (AF), pacemaker implantation, and all-cause mortality. In their AF analysis, they adjusted for electrocardiographic left ventricular hypertrophy (LVH) as a confounder, consistent with an article from the LIFE study that showed the relationship between LVH and AF.2 However, a subsequent article3 from the LIFE study reported that regression of LVH was associated with reduction of sudden cardiac death, and LVH has been reported to be a risk factor for cardiovascular mortality.4