BACKGROUND: Atrial fibrillation (AF) is common in idiopathic dilated cardiomyopathy (IDC). We explored the clinical characteristics of IDC patients with chronic AF compared with those with sinus rhythm (SR). METHODS: A group of patients with IDC underwent extensive non-invasive and invasive evaluation during a hospitalization period. The patients were further divided into two groups with AF (n = 19) and SR (n = 68). RESULTS: Left atrial diameter was greater (P<0·001), left ventricular end-diastolic diameter smaller (P<0·05), left ventricular end-diastolic and end-systolic volumes smaller (P<0·01 for all), mean pulmonary artery pressure and pulmonary capillary wedge pressure higher (P<0·05 for both), cardiac output and maximal oxygen consumption lower (P<0·01 and P<0·05, respectively), and the levels of N-terminal pro-brain natriuretic peptide and interleukin-6 higher (P<0·05 for both) in AF group compared with SR group. Left ventricular ejection fraction and left ventricular end-diastolic pressure were similar in both groups. CONCLUSIONS: In spite of otherwise more unfavourable prognostic factor profile, left ventricular size was observed to be smaller in chronic AF compared with SR in well-characterized patients with IDC. The confirmation and possible explainers of this paradoxical phenomenon need further studies in larger patient cohorts.
BACKGROUND:Atrial fibrillation (AF) is common in idiopathic dilated cardiomyopathy (IDC). We explored the clinical characteristics of IDC patients with chronic AF compared with those with sinus rhythm (SR). METHODS: A group of patients with IDC underwent extensive non-invasive and invasive evaluation during a hospitalization period. The patients were further divided into two groups with AF (n = 19) and SR (n = 68). RESULTS: Left atrial diameter was greater (P<0·001), left ventricular end-diastolic diameter smaller (P<0·05), left ventricular end-diastolic and end-systolic volumes smaller (P<0·01 for all), mean pulmonary artery pressure and pulmonary capillary wedge pressure higher (P<0·05 for both), cardiac output and maximal oxygen consumption lower (P<0·01 and P<0·05, respectively), and the levels of N-terminal pro-brain natriuretic peptide and interleukin-6 higher (P<0·05 for both) in AF group compared with SR group. Left ventricular ejection fraction and left ventricular end-diastolic pressure were similar in both groups. CONCLUSIONS: In spite of otherwise more unfavourable prognostic factor profile, left ventricular size was observed to be smaller in chronic AF compared with SR in well-characterized patients with IDC. The confirmation and possible explainers of this paradoxical phenomenon need further studies in larger patient cohorts.