Clinical predictors and consequences of atrial fibrillation after surgical myectomy for obstructive hypertrophic cardiomyopathy

A trial fibrillation (AF) during the hospital recovery period after cardiac operations occurs in 25% to 40% of patients, depending on the type of operation performed.(1-5) Postoperative atrial fibrillation (POAF) has been associated with an increase in complications not involving arrhythmia, longer intensive care unit and hospital stays, and increased costs.(4,6-9) Severe symptoms of obstructive hypertrophic cardiomyopathy (HC) can be relieved with septal myectomy, with low procedural mortality and significant and sustained symptomatic benefit.(10,11) As in almost all patients with HC, candidates for this operation who have an outflow tract obstruction also have significant diastolic dysfunction.(12) This places an increased hemodynamic load on the atrium, which can lead to cellular derangement and AF. Additionally, patients with diastolic dysfunction in the early phases (nonrestrictive filling patterns) are more dependent on the atrial contribution to left ventricular filling and would be more likely to have clinical deterioration with the onset of AF. Therefore, patients with obstructive HC undergoing septal myectomy may be at increased risk of POAF and consequently have more postoperative difficulties. This investigation was designed to assess the clinical effect and predictors of POAF for patients who have undergone surgical septal myectomy.