RESUMO
The authors suggest a new method using Doppler echocardiography for the evaluation of cardiac performance. Doppler echocardiography permits the calculation of left ventricular (LV) ejection force (according to Newton's second law of motion). The ejection force was calculated in 36 patients with heart failure subgrouped into 3 groups based on ejection fraction (EF) (> 60%; 41-60%; < 40%) compared to 11 normal subjects. The LV ejection force showed a good linear correlation with LV ejection fraction (r = 0.86). Data of the study suggest that the LV ejection force is a valuable and accurate index for the assessment of cardiac performance, especially in early stages of disease.
Assuntos
Ecocardiografia Doppler , Função Ventricular Esquerda , Idoso , Cardiomiopatia Dilatada/diagnóstico por imagem , Cardiomiopatia Dilatada/fisiopatologia , Doença das Coronárias/diagnóstico por imagem , Doença das Coronárias/fisiopatologia , Ecocardiografia Doppler/estatística & dados numéricos , Feminino , Insuficiência Cardíaca/diagnóstico por imagem , Insuficiência Cardíaca/fisiopatologia , Humanos , Masculino , Pessoa de Meia-Idade , SístoleRESUMO
The present study investigates 16 patients with aortic regurgitation (AR), and 10 patients with mitral regurgitation (MR). Before operation, all the 26 patients had increased telediastolic and telesystolic diameters. The patients were divided into two groups, as a function of the postoperative values of the telediastolic diameter: group A--with the telediastolic diameter within normal limits; group B--with the persistence of the increased values of the telediastolic diameter. In the case of the patients with AR, the following postoperative situation was noticed: in group A: the peak systolic stress (PSS) was increased, the shortening fraction (SF) in the telesystolic stress (TSS) within normal limits; in group B: PSS and TSS were increased, and ST depressed. 8 months after the valvular correction, in group A: PSS, TSS and SF were normal; in group B: the changes in PSS and TSS continued and was lowered. In the case of the patients with MR, before operation, in group A: PSS was slightly increased while TSS and SF were normal; in group B: PSS was slightly increased, TSS, increased and SF depressed. 8 months after the surgical correction: in group A: PSS and SF decreased; in group B: echocardiographic changes continued. Therefore, in the group B patients with MR and AR, the persistence of the increased values of PSS, TSS leads to the postoperative decrease of SF (post-charge in excess).