Atrial fibrillation is one of the most common arrhythmia, reported in the hemodynamically unstable patients in the intensive care unit. Loss of atrial contraction and the sequential atrioventricular contraction decrease the overall cardiac output which results in severe inadequate tissue perfusion. Medications aim for rate and rhythm control are recommended to treat new onset atrial fibrillation. These drugs (verapamil, diltiazem, amiodarone and beta blockers) may further compromise the patients' cardiac output by its' negative inotropic effect.