Función de los músculos inspiratorios, parámetros hemodinámicos y disnea en pacientes con estenosis mitral / Inspiratory muscle function, hemodynamic parameters and dyspnea in patients with mitral valve stenosis
We studied 13 patients (9 in NYHA class II and 4 in class III). Endurance was evaluated using a two minute incremental threshold loading test, to obtain the maximal sustainable inspiratory pressure (SIP), and maximal inspiratory load (MIL). During the test, cardiac output (CO), mean pulmonary and capillarypressures (PAP and PCP, respectively), were evaluated.
Results:
Compared to six normal subjects, MS patients had reduced SIP and MIL (p <0.01), which correlated with baseline index of dyspnea (r= 0.57 and r=0.52, respectively, p <0.05). At the end of the test period, basal CO, cardiac index (CI), PAP and PCP increased from 3.4 to 4.0 l/min-1; 2.1 to 2.5 l/min-1/m-2; 15 to 25 and 11 to 18 mmHg, respectively (p <0.01). No relationship between IME and hemodynamicparameters was found.
Conclusions:
IME is reduced and is closely related to dyspnea in these patients with MS. The observed low CI, suggests that muscle underperfusion could contribute to this dysfunction during the inspiratory effort.