In patients with AS, LV dysfunction and low transvalvular gradients, contractile reserve on DSE is associated with a low operative risk and good long-term prognosis after valve surgery. In contrast, operative mortality remains high in the absence of contractile reserve.
The analysis of flow propagation velocity showed that early filling is highly dependent on left ventricular relaxation rate, particularly through the phenomenon of asynchrony. During ischemia, the premature cessation of late filling is associated with increased diastolic pressures.
AimsThe aim of this study was to determine whether myocardial velocity gradients assessed by M-mode colour Doppler tissue imaging could be of clinical relevance and represent reliable indicators of regional left ventricular function after acute myocardial infarction.
Methods and ResultsAmong 64 consecutive patients with a first acute myocardial infarction, in 50 who had a marked asynergy in the parasternal short-axis view at the mid-papillary muscle level, myocardial velocities and velocity gradients were assessed in the anteroseptum and posterior wall by M-mode Doppler tissue imaging. Similar measurements were obtained in 11 matched healthy volunteers who served as a control group.In patients with anterior myocardial infarction, the peak myocardial velocity gradient in the anteroseptum was significantly lower when compared with controls (mean [SD] 0·0 0·5 vs 1·1 0·7 s 1 during systole, P<0·01; and 0·3 0·6 vs 2·0 0·5 s 1 during diastole, P<0·01). Conversely, the peak systolic myocardial velocity gradient in the posterior wall was significantly higher than in controls (2·6 1·2 vs 1·8 1·2 s 1 , P<0·05).In patients with inferior myocardial infarction, the peak velocity gradient in the posterior wall was significantly lower when compared with healthy subjects (0·9 0·6 vs 1·8 1·2 s 1 during systole and 1·4 1·4 vs 4·9 1·2 s 1 during diastole, both P<0·01). The peak systolic tissue velocity gradient in the anteroseptum was significantly higher than in controls (2·1 1·0 vs 1·1 0·7 s
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