Author + information
- Received June 15, 1992
- Revision received December 21, 1992
- Accepted December 22, 1992
- Published online June 1, 1993.
- Jan J. Piek, MD∗,
- Jacques J. Koolen, MD,
- Alexander C.Metting van Rijn, Msc,
- Hans Bot, PhD,
- Gerard Hoedemaker, MD,
- George K. David, MD,
- Arend J. Dunning, MD, FACC,
- Jos A.E. Spaan, PhD and
- Cees A. Visser, MD, FACC
- ↵∗Address for correspondence: Jan J. Piek, MD, Department of Cardiology, Academic Medical Center, Meibergdreef 9,1105 AZ Amsterdam, The Netherlands.
Objectives. The present study was designed to evaluate a new method for assessing coronary collateral flow and resistance in conscious humans.
Background. Earlier pathomorphologic and invasive studies have indicated that collateral vessels are important for salvage of myocardium at risk in acute myocardial infarction. Only a few clinical studies have attempted to express the development of the collateral vascular bed in terms of flow or resistance.
Methods. Angiography and flow velocity measurements of the contralateral coronary artery were performed in 38 patients undergoing coronary angioplasty for one-vessel disease. Coronary flow velocity was assessed by zero-crossing frequency analysis in 37 patients and, additionally, by fast Fourier transform spectral analysis in 23. Collateral flow was determined by the decrease of flow velocity after balloon deflation. Mean aortic pressure and coronary wedge pressure were assessed for calculation of collateral vascular resistance.
Results. Angiography of the contralateral artery during balloon inflation revealed the presence of collateral vessels in 26 patients (recruitable collateral vessels in 19). Fast Fourier transform spectral analysis demonstrated a significant transient increase of flow velocity during brief coronary occlusion in 15 patients with collateral vessels compared with 8 patients without collateral vessels (4.8 ± 1.3% vs. 23.4 ± 17.2%, p < 0.001). A transient increase in flow velocity (>10%) was less evident by zero-crossing frequency analysis than by fast Fourier transform spectral analysis (sensitivity 8% vs. 87%). The relative resistance of the collateral vascular bed was significantly reduced when collateral vessels were present during coronary occlusion (4.4 ± 3.8 vs. 16.9 ± 4.6, p < 0.001). Furthermore, electrocardiographic signs of ischemia were less present in those 15 patients with collateral vessels (p < 0.05).
Conclusions. The beneficial effect of collateral vessels during brief coronary occlusion is exerted by a significant increase of flow in the contralateral artery in combination with a reduced resistance in the collateral vascular bed. The method presented is capable of expressing the development of the collateral vascular bed in terms of flow and resistance.
☆ This study was supported by Grant 88.213 from the Dutch Heart Foundation, The Hague, The Netherlands.
- Received June 15, 1992.
- Revision received December 21, 1992.
- Accepted December 22, 1992.