Related Experiment Videos
Arterial waves in humans during peripheral vascular surgery.
1Physiological Flow Study Group, Department of Bioengineering, Imperial College of Science, Technology and Medicine, Prince Consort Rd., London SW7 2BY, UK. a.khir@ic.ac.uk
Clinical Science (London, England : 1979)
|November 29, 2001
Summary
Aortic clamping during vascular surgery increases arterial wave speed and alters reflected wave timing, raising left ventricle hydraulic work. This may contribute to intra-operative myocardial ischemia in patients with peripheral vascular disease.
Area of Science:
- Cardiovascular Physiology
- Vascular Surgery
- Hemodynamics
Background:
- Peripheral vascular disease often requires aortic clamping during surgery.
- Aortic clamping can impact cardiac function and hemodynamics.
- Understanding arterial wave dynamics during clamping is crucial for patient outcomes.
Purpose of the Study:
- To investigate the effects of aortic clamping on arterial wave characteristics.
- To quantify changes in wave speed, reflected waves, and hydraulic work.
- To explore the implications for left ventricle afterload and oxygen consumption.
Main Methods:
- Simultaneous pressure and velocity measurements in the ascending aorta of 10 patients undergoing aortic-iliac surgery.
- Utilized catheter tip manometer and Doppler ultrasound.
- Calculated hydraulic work, analyzed reflected waves (wave-intensity), and determined wave speed (PU-loop method).
Main Results:
- Wave speed increased by approximately 32% during clamping (P<0.05).
- Reflected waves arrived 30 ms earlier and lasted 25% longer (P<0.05), with unchanged peak intensity.
- Left ventricle hydraulic systolic work and reflected wave energy increased by 27% and 20% respectively (P<0.05).
Conclusions:
- Increased wave speed during clamping leads to earlier reflected waves, suggesting increased afterload.
- The prolonged and intensified reflected wave increases hydraulic work, potentially raising myocardial oxygen demand.
- These hemodynamic changes may contribute to intra-operative left ventricle dysfunction in patients with peripheral vascular disease.