Ventricular outflow tract obstruction secondary to leiomyosarcoma of the right ventricle.

Primary leiomyosarcomas of the heart, particularly those affecting the right ventricle, are uncommon. We report the case of a 70-year-old Belgian woman presenting with the symptoms of progressive exertional dyspnea and left-sided pleuritic pain. A leiomyosarcoma which originated from the right lateral ventricle wall, causing pulmonary outflow obstruction, was diagnosed. Pathology revealed a neoplasm with a myxoid stroma, high mitotic activity and nuclei expressing atypia. Immunohistochemical staining was positive for vimentine and desmin. Seven months after complete surgical resection the tumor relapsed. This case demonstrates the poor outcome, the high relapse rate and inefficiency of treatment associated with primary cardiac leiomyosarcomas. The current literature regarding the incidence, diagnostic techniques, treatment strategies and survival rates of this rare but terminal disease is reviewed.

Mechanism of phase V in the single breath washout curve.

The underlying mechanism of the occurrence of a downward phase V at the end of a bolus washout curve was investigated in three healthy subjects. Phase V appeared not to originate from apical zones with low concentration of tracer gas but from dependent lung zones, which were not pathological. Indeed: 1) a reversed, upward, terminal slope was obtained when the bolus had been directed to the lung base by imposing a transition of the body through 180 degrees between inspiration and expiration or by inhaling a bolus close to TLC; 2) phase V was also present on N2 washout curves and, thus, originated from zones with smaller RV/TLC than the apical ones. Phase V increased with flow rate.

Gravity dependence of phases III, IV, and V in single-breath washout curves.

The gravity dependence of phases III (IIIa and IIIb), IV, and V of simultaneously performed He-bolus and N2-resident gas single-breath washout curves was studied in different body positions by the technique of 180 degrees body inversion between inspiration and expiration. Phase IIIa was mainly determined by nongravitational factors. Phase IIIb was influenced by gravitational, as well as nongravitational, factors. The former were more important with the bolus method in both lateral decubitus positions and the latter with the N2 method in the prone and supine positions. Phases IV and V were mainly gravity dependent. The difference in gravity dependence between the He and N2 methods appeared to be correlated with the vertical interregional concentration gradients of both gases; indeed the vertical gradient was larger for the 133Xe bolus inhaled at residual volume (which is comparable to the He-bolus distribution) than for the 133Xe residual volume-to-total lung capacity ratio (which is comparable to the N2-resident gas distribution). The greater gravity dependence in the lateral decubitus positions than in the supine or prone postures was related to the larger vertical interregional concentration difference as well as to the more pronounced sequential ventilation in the former positions. Finally the negligible effect of gravity on phase IIIa, its moderate effect on phase IIIb, and its predominant effect on phases IV and V were in agreement with the increased sequential filling and emptying due to gravity near residual volume.