Methods of measuring myocardial blood flow in humans
| Autor: | Robert F. Wilson, Carl W. White, M. L. Marcus |
|---|---|
| Rok vydání: | 1988 |
| Předmět: |
medicine.medical_specialty
medicine.medical_treatment Thermodilution Indicator Dilution Techniques Hemodynamics Coronary Angiography Coronary artery disease Coronary Circulation Internal medicine medicine Humans Ultrasonography Cardiac catheterization business.industry Blood flow medicine.disease Magnetic Resonance Imaging Radiographic Image Enhancement Great vessels Echocardiography Temporal resolution Coronary vessel Cardiology Gases Rheology Tomography X-Ray Computed Cardiology and Cardiovascular Medicine business Perfusion Tomography Emission-Computed |
| Zdroj: | Progress in Cardiovascular Diseases. 31:79-94 |
| ISSN: | 0033-0620 |
| Popis: | T HE DEVELOPMENT OF cardiac catheterization, begun by Forssmann and Cournand in the 1930s and 194Os, opened cardiac hemodynamic investigations to clinical investigators studying pathologic states in humans, thus removing the necessity of relying entirely on information obtained from animal experimentation. Despite the early development of clinical methods for measuring pressure in cardiac chambers and great vessels, and total flow emanating from the heart, techniques for quantitating flow to selected organs have been slow to develop. This has been particularly true for coronary blood flow measurements in humans. Over the past several decades, advances in measurement technologies have allowed physiologists to obtain a sophisticated understanding of regulation of coronary blood flow in animals. However, most of these techniques, developed and used for animal investigations, have not been directly transferable to human patients. Until relatively recently, only global left ventricular perfusion could be measured in conscious humans. The spatial resolution of commonly used techniques to measure myocardial flow in humans was crude, and the temporal resolution poor. These unsophisticated approaches contrast strikingly with the elegant methods available for animal studies, which allow perfusion in the myocardium to be measured with a spatial resolution in microns’ and a temporal resolution in milliseconds.* The necessity of relying on global coronary flow for estimates of regional perfusion is particularly inappropriate for the myocardium, since regional heterogeneity in perfusion is the rule in atherosclerotic coronary artery disease, and not infrequent in other pathologic states. The requirements for spatial resolution of perfusion in the myocardium are doubly demanding, since in addition to sophisticated lateral edge detection, an ideal measurement technique should be able to detect transmural differences in perfusion. The requirements for temporal resolution of perfusion in the myocardium are also stringent, since metabolic and neurogenic factors can alter coronary flow over a wide range with very short time constants. It is not surprising that because of the severe restraints imposed by the nature of the target organ, no one technique approaches that which would be considered ideal. Such an ideal method for measuring coronary blood flow in humans would allow detailed spatial resolution, have a rapid frequency response, allowing it to detect phasic changes in flow, and be minimally invasive. Unfortunately, no such ideal method presently exists. The purpose of this review is to evaluate those techniques that are in present use for measuring myocardial blood flow in humans. Newer techniques under active investigation will also be briefly examined. Emphasized in this discussion will be those techniques with which the authors have the greatest personal experience. The advantages and limitations of each technique will be compared to a theoretic ideal agent. The methodologies will be grouped into the following categories: electromagnetic flow meters, diffus |
| Databáze: | OpenAIRE |
| Externí odkaz: |
|