Abstract 2486: Early Diastolic Mitral Annulus Lengthening Velocity Reflects Coupling between Systolic and Diastolic Function
Background: Peak early-diastolic mitral annulus velocity (E’) by tissue Doppler imaging (TDI) has been introduced as a marker of diastolic function. This study investigates mechanisms of E’.
Methods: In 7 anesthetized dogs we measured E’ and systolic long-axis shortening (SS) by sonomicrometry and TDI, and the time constant (tau) of LV relaxation by micromanometer. In 8 healthy subjects (HS) we measured E’ by TDI and SS by M-mode echo at baseline and during lower body negative pressure (LBNP). We studied 6 patients with myocardial infarction, acutely and after 6 –12 months.
Results: In dogs there was a strong correlation between E’ and SS (Fig 1⇓), suggesting that E’ is determined primarily by systolic function. However, during ischemia which increased tau (p<<med>0.01), the relationship between E’ and LV end-diastolic pressure (LVEDP), shifted markedly downwards (Fig 2⇓). During volume loading which increased LVEDP (p<0.01), the relationship between E’ and tau shifted markedly upwards (Fig 3⇓). Consistent with findings in dogs, healthy subjects demonstrated a strong correlation between E’ and SS during LBNP (Fig 4⇓). However, in patients with chronic myocardial infarction the relationship between E’ and systolic shortening was shifted downwards (Fig 4⇓).
Conclusions: During a wide range of hemodynamic conditions there were strong correlations between E’ and SS. The shifts in the relationships between E’ and LVEDP during ischemia and between E’ and tau during volume loading, indicates that diastolic function modulates E’. These observations indicate a tight coupling between systolic and diastolic function, and challenge the concept that E’ is a specific marker of LV relaxation.