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Left ventricular function in patients with centrifugal left ventricular assist device
M S Verani1, M E Sekela, J J Mahmarian
1Department of Medicine, Baylor College of Medicine, Houston, Texas 77030.
Insights
Patients with assist devices (AD) for left ventricular (LV) dysfunction showed improved LV ejection fraction (EF) when AD flow was reduced. Weaning success correlated with EF improvement, indicating AD flow optimization is key for recovery.
Area of Science:
- Cardiology
- Biomedical Engineering
Background:
- Severe left ventricular (LV) dysfunction often necessitates mechanical circulatory support.
- Centrifugal assist devices (AD) are used to manage postoperative LV dysfunction.
Purpose of the Study:
- To evaluate the impact of assist device (AD) flow on left ventricular (LV) ejection fraction (EF) and patient outcomes.
- To determine if changes in LV-EF with varying AD flows correlate with successful weaning and long-term survival.
Main Methods:
- Blood pool radionuclide angiography was used to assess LV ejection fraction (EF) in 17 patients with centrifugal assist devices (AD).
- LV-EF was measured during maximal and minimal AD flows, and during maximal LVAD flow rates.
Main Results:
- Patients weaned from the AD had a higher LV-EF during maximal flow compared to those who could not be weaned (18% vs. 9%, p=0.04).
- In patients who could be weaned, decreasing AD flow from maximal to minimal significantly increased LV-EF (15% to 33%, p<0.005).
- Long-term survivors demonstrated a substantial increase in LV-EF with decreased AD flow (182% increase), unlike short-term survivors (44% increase).
Conclusions:
- Optimizing assist device (AD) flow by reducing it can significantly improve left ventricular (LV) ejection fraction (EF).
- The ability to increase LV-EF by adjusting AD flow is a strong indicator of successful weaning and long-term survival in patients with LV dysfunction.
Abstract:
We used blood pool radionuclide angiography to study the left ventricular (LV) ejection fraction (EF) in 17 patients with a centrifugal assist device (AD) placed because of severe postoperative LV dysfunction. During maximal LVAD flow, the 12 patients who could be weaned had a higher LV-EF than the 5 who could not be weaned (18 +/- 12% vs. 9 +/- 2%, p = 0.04). Sequential studies during variable AD flows in 12 patients revealed an increase in LV-EF from 15 +/- 7% at maximal flows to 33 +/- 8% during minimal flows (p less than 0.005) in the 10 patients who could be weaned and no change in LV-EF in 2 patients who could not be weaned. The LV-EF during maximal LVAD flow rates was similar in the 10 patients with long-term survival (192 +/- 129 days) and in the 7 patients with only short-term (9 +/- 6 days) survival (LV-EF 17 +/- 12% vs. 12 +/- 6%, p = ns). The long-term survivors, however, had a substantial increase in LV-EF from 20 +/- 13% to 34 +/- 9% (p less than 0.01), as the LVAD flow was decreased from maximal to minimal, whereas the short-term survivors had an insignificant increase in LV-EF from 12 +/- 7% to 21 +/- 12% (p = ns). The long-term survivors increased the LV-EF from maximal to minimal LVAD flows by 182%, in contrast with the short-term survivors, who increased the LV-EF by only 44%.(ABSTRACT TRUNCATED AT 250 WORDS)