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Effects of Hemopump support on left ventricular unloading and coronary blood flow
N Shiiya1, R Zelinsky, P H Deleuze
1Centre de Recherches Chirurgicales, CNRS URA 1431, Association Claude Bernard, Hôpital Henri Mondor, Créteil, France.
Insights
The Hemopump (HP) improves cardiac output and blood flow in failing hearts. This device reduces oxygen demand and enhances coronary blood flow, benefiting ischemic and decompensated cardiac conditions.
Area of Science:
- Cardiovascular Physiology
- Medical Devices
- Cardiac Surgery
Background:
- Left ventricular (LV) dysfunction and myocardial ischemia significantly impair cardiac performance.
- Effective hemodynamic support is crucial for managing ischemic and failing hearts.
- The Hemopump (HP) is a device designed to assist cardiac function.
Purpose of the Study:
- To evaluate the effects of the Hemopump (HP) on left ventricular (LV) and coronary hemodynamics.
- To assess HP performance under conditions of myocardial ischemia and cardiac failure.
- To determine the impact of varying HP speeds on hemodynamic parameters.
Main Methods:
- Acute, open-chest dog preparation (n=6) under anesthesia.
- Coronary blood flow velocity measured using an intracoronary Doppler catheter.
- Hemodynamic assessments performed at minimal (HP1) and maximal (HP7) pump speeds during control, ischemia (LAD ligation), and failure (diagonal branch ligation) states.
Main Results:
- Increasing HP speed (HP1 to HP7) increased cardiac output in ischemia and failure.
- HP support increased mean aortic pressure and systemic vascular resistance across all conditions.
- HP significantly decreased LV external work, LV end-diastolic pressure (in ischemia), and LV systolic pressure/pressure-rate product (in failure).
- HP improved the coronary blood flow/O2 demand ratio in failing hearts.
Conclusions:
- Hemopump support effectively reduces myocardial oxygen demand through LV decompression.
- The HP enhances coronary blood flow relative to oxygen demand in ischemic and failing hearts.
- HP demonstrates potential as a therapeutic device for managing complex cardiac conditions.
Abstract:
The effects of the Hemopump (HP) on left ventricular (LV) and coronary hemodynamics, with and without myocardial ischemia, were studied in an acute, anesthetized, open-chest dog preparation (n = 6). Coronary blood flow velocity in the left circumflex was assessed with an intracoronary Doppler catheter. Measurements were made at two pump speeds (minimal = HP1 and maximal = HP7) before coronary ligation (control), after ligation of the LAD (ischemia), and after induction of cardiac failure by multiple ligations of the diagonal branches (failure). Changing from HP1 to HP7 resulted in 1) Increased total cardiac output in ischemia and failure; 2) Increased mean aortic pressure and systemic vascular resistance in control, ischemia, and failure; 3) Decreased LV external work (LV systolic pressure X stroke volume) in control, ischemia, and failure; 4) Decreased LV end diastolic pressure in ischemia; 5) Decreased LV systolic pressure and pressure-rate product in failure; and 6) Increased coronary blood flow/O2 demand ratio in failure. Hemopump support reduced O2 demand by LV decompression, and improved blood flow/O2 demand ratio in the nonoccluded coronaries of ischemic, failing hearts.