Interatrial block - a novel risk factor for acute mesenteric ischemia.

Interatrial block (IAB; P-wave duration ≥110 milliseconds) denotes a conduction delay between the two atria. IAB has been shown to have a strong correlation with atrial arrhythmias, left atrial enlargement, left atrial electromechanical dysfunction and cerebral thromboembolism. Our study sought to determine whether there was an increased incidence of IAB in patients with acute occlusive mesenteric ischemia. Medical records of patients admitted with a diagnosis of acute mesenteric ischemia (AMeI) from January 2009 to March 2011 were reviewed retrospectively. One hundred seventy-two out of 342 patients reviewed, qualified after excluding mechanical surgical obstruction, suspected non-occlusive mesenteric ischemia due to shock/hypoperfusion, and mesenteric venous thrombosis. Of 99 patients who were in normal sinus rhythm without prior history of atrial arrhythmia, 88 (88.9 %) had IAB. This was more than twice the average prevalence of IAB of two general hospital populations (41 % and 47 % as demonstrated by two previous studies). IAB may thus represent a novel risk factor for AMeI as it does for embolic stroke.