[Integrated echocardiography (transthoracic-transesophageal) in the differential diagnosis of left atrial myxoma. Description of three clinical cases]. / L'ecocardiografia integrata (transtoracica-transesofagea) nella diagnosi differenziale del mixoma atriale sinistro. Descrizione di tre casi clinici.

Myxomas are the most common of all primary cardiac tumors among adults; most of them originate from the left atrium in the area of the fossa ovalis. Although atrial myxomas are histologically and clinically benign tumors, they can rarely cause severe complications including embolization and sudden death caused by left ventricular outflow tract obstruction and coronary or cerebral embolization. Echocardiography (Transthoracic and transesophageal) has been considered as the procedure of choice for the diagnosis of atrial myxomas. We report 3 cases in which it has been echocardiographically observed at left intra-atrial mass with similar motion behavior and attachment site, where transesophageal echocardiography has been very important to correctly lead the differential diagnosis (between atrial myxoma and atrial thrombus).

[Myosin isoforms in skeletal muscle in patients with chronic heart decompensation: distribution and correlation with with exercise tolerance]. / Le isoforme miosiniche nel muscolo scheletrico del paziente con scompenso cronico di cuore: distribuzione e correlazione con la tolleranza allo sforzo.

Chronic heart failure (CHF) is accompanied by a reduced exercise capacity, and the symptoms can be at least in part explained by qualitative and quantitative changes in the skeletal muscle composition and metabolism. We have correlated the myosin heavy chain (MHC) composition of the gastrocnemius in 20 patients with different degrees of CHF to expiratory gases measured during maximal cardiopulmonary exercise testing, NYHA functional class and echocardiographic parameters. MHC composition was determined electrophoretically in skeletal muscle needle microbiopsies and the percent distribution calculated by laser densitometry. There was no correlation between ejection fraction, left ventricular end-diastolic and end-systolic diameters and MHC composition. The percentage of MHC 1 (slow aerobic isoform) was positively correlated with peak VO2 (r2 = 0.5, p = 0.0004), ventilatory threshold (VT, r2 = 0.33, p = 0.008), and O2 pulse (peak VO2/HR, r2 = 0.40, p = 0.003). There was a negative correlation between MHC 2a and 2b (fast isoforms) and peak VO2 (r2 = 0.38 and 0.37, p = 0.004, respectively), VT (r2 = 0.2, p = 0.05; r2 = 0.34, p = 0.007, respectively) and O2 pulse (r2 = 0.39, p = 0.003; r2 = 0.23, p = 0.03, respectively). NYHA functional class was also negatively correlated with the same parameters (r2 = 0.2, p = 0.01; r2 = 0.4, p = 0.001; r2 = 0.34, p = 0.006, respectively) as well as with MHC 1 (r2 = 0.62, p = 0.0001). A positive correlation was found between NYHA functional class and MHC 2a and 2b (r2 = 0.46, p = 0.001; r2 = 0.41, p = 0.002, respectively). The severity of heart failure is paralleled by a shift of the MHC pattern toward the fast MHC 2b. The correlation between the magnitude of the MHCs shift, from the slow aerobic to the fast type, with both clinical parameters (NYHA functional class) and functional measurements (peak VO2, VT, O2 pulse) of exercise capacity seem to suggest that changes in skeletal muscle composition may play a key role in exercise tolerance in patients with CHF.