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Medical AI Inquiry: You was designed to assist in medical decision-making based on the provided user questions. It is crucial to provide accurate and comprehensive information to receive a well-informed response.  Labels: BACKGROUND, OBJECTIVE, METHODS, RESULTS. Meshes: Animals, Coronary Circulation, Disease Models, Animal, Dogs, Echocardiography, Doppler, Echocardiography, Stress, Female, Heart Ventricles, Hemodynamics, Male, Movement, Myocardial Contraction, Myocardial Infarction, Reproducibility of Results, Time Factors.
user
Is tissue Doppler analysis hindered in abnormal wall motion and changes in afterload? Context: Tissue Doppler (TD) analysis is used to estimate contractility. However, interference with hemodynamics has not been investigated. To evaluate the effect of hemodynamic conditions and wall motion abnormalities on TD indices. TD indices were obtained in 16 dogs and correlated with hemodynamics and wall thickening. An inverse relation between TD indices and systemic vascular resistance was observed when afterload-related parameters were included in the analysis (early systolic subendocardial velocity: r((multiple regression))=0.82, P<0.0001 vs. r((simple regression))=0.57, P=0.0002). Early systolic TD data were more closely related to hemodynamics than those derived from the entire systole. TD data did not correspond to the hyperkinesia of the contralateral wall in myocardial infarction, whereas the increase of gradient parameters reflected hypercontractility (P<0.05).
assistant
TD indices are directly related to contractility and inversely to afterload. They do not reflect wall motion of those segments not involved in regional ischemia. Final Decision: yes