The relation between blood and tissue magnesium levels and development of atrial fibrillation after coronary artery bypass surgery.

Objective: Atrial fibrillation (AF) is a common complication of cardiovascular surgery and its mechanisms are not well understood. The aim of our study was a prospective investigation of the relationship between AF development and tissue or blood magnesium levels.

Methods: This prospective observational study evaluated 20 patients undergoing elective initial coronary artery bypass graft (CABG) surgery.

[Assessment of the efficacy of bisoprolol administration by cardiopulmonary exercise testing in patients with heart failure].

Objective: It is well known that long-term therapy with beta-blockers reduces morbidity and mortality, improves left ventricular function in patients with heart failure. However the effect of beta-blockade on exercise tolerance in patients with heart failure remains unclear. In the present study we evaluated effects of the addition of bisoprolol to standart therapy with a diuretic and an angiotensin converting enzyme (ACE) inhibitor on exercise capacity in patients with chronic heart failure.