N.H. Pijls – författare

Coronary flow reserve is a functional measure of stenosis severity re­ flecting the integrated effects of its geometry including percent stenosis, absolute lumen area, length and shape. Its clinical application has been primarily qualitative in non-invasive, perfusion imaging. Measurement of coronary flow reserve during routine coronary arte­ riography has been an elusive goal. Transit time and indicator dilution techniques for assessing coronary flow reserve at cardiac catheteriza­ tion are associated with marked variability compared to microspheres or flow meters, thereby making their use questionable in comparison to the precision of good quantitative arteriography. Coronary flow reserve measured by special Doppler catheters as an adjunct to coronary arte­ riography shows in man the value of this integrated functional measure of stenosis severity and the limitations of percent diameter narrowing as a measure of its physiologic significance. However, Doppler catheters require additional instrumentation that is not yet an integral part of coronary arteriography and provide measures of absolute coronary flow reserve only. Relative maximum flow or relative flow reserve has been demon­ strated to be an important independent, complimentary descriptor of stenosis severity independent of fluctuating hemodynamic conditions. The method developed for DSA by Nico Pijls, described in this book is the first approach for assessing relative coronary flow reserve as a part of routine coronary arteriography by DSA. The theory and basic con­ cepts are well developed, experimental validation thorough and clinical applications timely.

A little bit more than two years after the first edition, we are pleased to publish the second edition of this book. More than half of the chapters have been remodeled and completed as the result of technical improvements and recently acquired clinical data. During these two years, the number of coronary pressure measurements performed worldwide both during diagnostic and interventional procedures has increased almost exponentially. Most of the initial problems associated with this new approach have been overcome. Many colleagues have explored new research avenues and in many catheterization laboratories the method has matured from a research toy to a clinical tool. Classical indications such as the intermediate stenosis and guidance of PTCA or stent implantation, have been largely extended and coronary pressure measurement has proven to be useful in multi vessel disease, diffuse disease, long and serial stenosis, after myocardial infarction, and in many other diagnostic and interventional situations encountered in the catheterization laboratory. Quite unexpectedly, this approach has also enforced the ties with our surgical colleagues in the selection of patients suitable for minimal invasive surgery or hybride revascularization. Also in mild and intermediate left main disease, there is a role for coronary pressure measurement in the process of decision making. We would like to express our gratitude to all those many colleagues who trusted and applied this new approach for the benefit of their patients. Aalst, Eindhoven, Bernard De Bruyne. Nico H. J. Pijls. March, 2000. Table of Contents (overview) 1 1.

A little bit more than two years after the first edition, we are pleased to publish the second edition of this book. More than half of the chapters have been remodeled and completed as the result of technical improvements and recently acquired clinical data. During these two years, the number of coronary pressure measurements performed worldwide both during diagnostic and interventional procedures has increased almost exponentially. Most of the initial problems associated with this new approach have been overcome. Many colleagues have explored new research avenues and in many catheterization laboratories the method has matured from a research toy to a clinical tool. Classical indications such as the intermediate stenosis and guidance of PTCA or stent implantation, have been largely extended and coronary pressure measurement has proven to be useful in multi vessel disease, diffuse disease, long and serial stenosis, after myocardial infarction, and in many other diagnostic and interventional situations encountered in the catheterization laboratory. Quite unexpectedly, this approach has also enforced the ties with our surgical colleagues in the selection of patients suitable for minimal invasive surgery or hybride revascularization. Also in mild and intermediate left main disease, there is a role for coronary pressure measurement in the process of decision making. We would like to express our gratitude to all those many colleagues who trusted and applied this new approach for the benefit of their patients. Aalst, Eindhoven, Bernard De Bruyne. Nico H. J. Pijls. March, 2000. Table of Contents (overview) 1 1.

Coronary flow reserve is a functional measure of stenosis severity re­ flecting the integrated effects of its geometry including percent stenosis, absolute lumen area, length and shape. Its clinical application has been primarily qualitative in non-invasive, perfusion imaging. Measurement of coronary flow reserve during routine coronary arte­ riography has been an elusive goal. Transit time and indicator dilution techniques for assessing coronary flow reserve at cardiac catheteriza­ tion are associated with marked variability compared to microspheres or flow meters, thereby making their use questionable in comparison to the precision of good quantitative arteriography. Coronary flow reserve measured by special Doppler catheters as an adjunct to coronary arte­ riography shows in man the value of this integrated functional measure of stenosis severity and the limitations of percent diameter narrowing as a measure of its physiologic significance. However, Doppler catheters require additional instrumentation that is not yet an integral part of coronary arteriography and provide measures of absolute coronary flow reserve only. Relative maximum flow or relative flow reserve has been demon­ strated to be an important independent, complimentary descriptor of stenosis severity independent of fluctuating hemodynamic conditions. The method developed for DSA by Nico Pijls, described in this book is the first approach for assessing relative coronary flow reserve as a part of routine coronary arteriography by DSA. The theory and basic con­ cepts are well developed, experimental validation thorough and clinical applications timely.

Cardiologists must answer three important questions when evaluating and treating patients with a coronary artery stenosis. As a physiologist: "What is the effect of this stenosis on coronary blood flow and myocardial function?"; as a clinician: " Is this lesion responsible for the patient''s symptoms?"; and finally as an interventionalist: "Will revascularization of this artery improve the patient?" Fundamentally, the answer to these questions can be given to a large extent by measuring coronary pressure. That is the rationale of writing this book. 1. 1 Historical overview. Andreas Gruentzig and most interventional cardiologists in the early days of PTCA, had the intuitive feeling that pressure measurements could help to establish the severity of a coronary stenosis and to monitor the progress and result of a coronary intervention. At that time, measuring coronary pressure by the balloon catheter was part of a standard procedure. A residual transstenotic gradient of less than 15 mmHg was generally considered as a good result. Later, however, it turned out that measuring these (resting) gradients with balloon catheters was inaccurate an only had a limited prognostic value. Moreover, because there was no consistent theory to correlate pressure measurements to blood flow, the interest in measuring coronary pressures faded and disappeared almost completely with the introduction of new balloon catheters not intended for pressure measurement.