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.

Inhalt

1. Introduction.- 2. The coronary circulation.- 3. Introduction to invasive assessment of the coronary circulation.- 4. Fractional flow reserve.- 5. Practical set-up of coronary pressure measurement.- 6. Validation of fractional flow reserve in animals.- 7. Validation of fractional flow reserve in humans.- 8. Independence of fractional flow reserve of hemodynamic loading conditions.- 9. Fractional flow reserve in normal coronary arteries.- 10. Fractional flow reserve to distinguish significant stenosis.- 11. Comparison of fractional flow reserve to non-invasive tests to detect reversible ischemia.- 12. Assessment of collateral blood flow by coronary pressure measurement.- 13. Fractional flow reserve for evaluation of coronary interventions.- 14. Myocardial fractional flow reserve and clinical outcome.- 15. Clinical cases.- 16. Conclusions and perspectives for the future.