Real-time cine MRI of ventricular septal motion: a novel approach to assess ventricular coupling.

The purpose of this study was to assess the feasibility of magnetic resonance imaging (MRI) to evaluate in real-time, the effects of respiration in ventricular septal motion and configuration in normal volunteers and cardiac patients. Real-time cine MRI studies, using the steady-state free precession (SSFP) technique, were performed in the cardiac short-axis during operator-guided deep inspiration and expiration in normal volunteers (N = 6), and in patients with constrictive pericarditis (CP; N = 6), restrictive cardiomyopathy (RCM; N = 4), chronic cor pulmonale (N = 5), and pericardial effusion. The respiratory effects on septal position and configuration during early ventricular filling were visually assessed. Results were compared with the short-axis breath-hold cine MRI studies, obtained at end-inspiration. In CP patients, onset of inspiration led to a leftward inversion in four of six patients and flattening of the septum in two of six patients during early ventricular filling. Septal abnormalities progressively disappeared during the following heartbeats. A similar pattern was found in one of six patients with pericardial effusion. The above pattern was absent in RCM patients. Although septal flattening during early inspiration was also found in two of six normal volunteers, flattening was minimal compared to that in CP patients. In all cor pulmonale patients, septal flattening or inversion was present, but this was not influenced by respiratory motion. Real-time cine MRI is a promising technique for determining the influence of respiration on septal motion and might be helpful in differentiating between different causes of impaired ventricular filling.