Assessment of cardiac remodeling in asymptomatic mitral regurgitation for surgery timing: a comparative study of echocardiography and magnetic resonance imaging.

BACKGROUND: Early surgery is recommended for asymptomatic severe mitral regurgitation (MR), because of increased postoperative left ventricular (LV) dysfunction in patients with late surgery. On the other hand, recent reports emphasized a "watchful waiting" process for the determination of the proper time of mitral valve surgery. In our study, we compared magnetic resonance imaging (MRI) and transthoracic echocardiography to evaluate the LV and left atrial (LA) remodeling; for better definitions of patients that may benefit from early valve surgery. METHODS: Twenty-one patients with moderate to severe asymptomatic MR were evaluated by echocardiography and MRI. LA and LV ejection fractions (EFs) were calculated by echocardiography and MRI. Pulmonary veins (PVs) were measured from vein orifices in diastole and systole from the tangential of an imaginary circle that completed LA wall. Right upper PV indices were calculated with the formula; (Right upper PV diastolic diameter- Right upper PV systolic diameter)/Right upper PV diastolic diameter. RESULTS: In 9 patients there were mismatches between echocardiography and MRI measurements of LV EF. LV EFs were calculated > or = 60% by echocardiography, meanwhile < 60% by MRI in these 9 patients. Severity of MR evaluated by effective regurgitant orifice area (EROA) didn't differ with preserved and depressed EFs by MRI (p > 0.05). However, both right upper PV indices (0.16 +/- 0.06 vs. 0.24 +/- 0.08, p: 0.024) and LA EFs (0.19 +/- 0.09 vs. 0.33 +/- 0.14, p: 0.025) were significantly decreased in patients with depressed EFs when compared to patients with normal EFs. CONCLUSIONS: MRI might be preferred when small changes in functional parameters like LV EF, LA EF, and PV index are of clinical importance to disease management like asymptomatic MR patients that we follow up for appropriate surgery timing.

Stress cardiomyopathy (Tako-Tsubo) following radiofrequency ablation in the right ventricular outflow tract.

A 44-year-old female undergoing radiofrequency ablation in the right ventricular outflow tract for symptomatic, frequent premature ventricular contractions developed stress cardiomyopathy (Tako-Tsubo). Stress cardiomyopathy was probably due to hyperadrenergic state induced by the procedure itself, dobutamine infusion, sympathetic nerve stimulation at the ablation site, and parasympathetic withdrawal with atropine administration.

Cardiovascular involvement in Behçet's disease.

The incidence and nature of cardiac involvement in Behçet's disease are not yet clearly documented. We first used transesophageal echocardiography in combination with resting and signal averaged electrocardiography to define cardiac involvement in Behçet's patients. Transthoracic and multiplane transesophageal echocardiography, and resting and signal averaged electrocardiography were performed in 35 Behçet's disease patients (9 women and 26 men, mean age: 38 +/- 12 years) and 30 normal subjects. Higher incidences of interatrial septum aneurysm (31% to 6%), mitral valve prolapse (25% to 3%), mitral regurgitation (40% to 6%) and aneurysmal dilatations of sinus valsalva and ascendan aorta were observed in the Behçet's disease patients than in the normal subjects. Mean QT dispersion and mean corrected QT dispersion values were significantly greater in the patients with Behçet's disease. Patients with interatrial septum aneurysm (and/or PFO), valvular dysfunction or proximal aorta dilatation had greater QT dispersion values than thase without these pathologies in the Behçet's group (63 +/- 11 vs 44 +/- 19 ms, 58 +/- 23 vs 41 +/- 24 and 60 +/- 27 vs 42 +/- 23 ms respectively, P<0.05). Positive signal averaged electrocardiography parameters were detected in 18 (51%) Behçet's disease patients compared with one (3%) in controls (P<0.001). Dilatation of the proximal aorta, interatrial septal aneurysm, mitral valve prolapse, and mitral regurgitation are the common findings of cardiac involvement in Behçet's disease. Increased dispersion of ventricular repolarisation and positive late potentials are also detected. QT dispersion is significantly higher in patients with these cardiac abnormalities. These findings suggest that cardiac involvement in this disorder is a diffuse process which involves both cardiac structure and vascular elements.