Coronary Angioplasty A Controlled Model For Ischemia

Coronary Angioplasty: A Controlled Model for Ischemia

Since the introduction of coronary angioplasty in 1977, this procedure has gained a steadily increasing position in the treatment of coronary artery obstmction. From the available evidence it can be estimated, that this thera peutic tool will get even more additional momentum of many ten-thousands of patients to be treated in the next few years, due to a growing fraction of patients who are candidates for this intervention. Information about the indications, benefits and risks of coronary angioplasty is accumulating rapidly in addition to publications about refinements of the technique itself. Recently, a number of investigators have realized that coronary angioplasty is not only a therapeutic tool, but can, during the procedure, be used as a source of diagnostic information. When the catheter is placed in a coronary artery obstruction, inflation of the balloon produces transient myocardial ischemia. Before, during, and after this period of severe ischemia, studies of the perfor mance of the myocardium at risk can be carried out. The fact that therapeutic coronary angioplasty is carried out in a cardiac catheterization laboratory which is by definition optimally equipped for the measurement of hemodynamic parameters, has probably also contributed to the effectuation of these investigations. The combination of hemodynamic and biochemical parameters with morphological information from the coronary angiogram can be utilized for the quantification of myocardial involvement and the success of coronary dilatation with angioplasty. Studies of interactions with pharmacological substances are also feasible and informative.

PTCA An Investigational Tool and a Non-Operative Treatment of Acute Ischemia

Obstruction of coronary blood flow and the resultant consequences are the center stage pathophysiologic events in cardiology today. The speculations of Jenner, Burns, Heberdin, McKenzie, Prinzmetal and many others had until now been left to observations of isolated tissue and intact animal experimentation. Only with the advent of Gruentzig's technique, which allowed us to 'work safely inside the coronary arteries' are we able to observe the effects of coronary occlusion in living conscious man. PTCA provides not only a therapeutic modality for non-operatively opening coronary obstructions, but has also provided the best model for studying the effects of acute ischemia on the heart. The procedure also lead the way to all other interventional cardiology developments, including modern thrombolysis in the setting of acute myocardial infarction. In his previous works, Serruys has examined how PTCA can serve as a model for studying acute ischemia. In this book, he and his co-authors discuss the effects of balloon-induced ischemia on the electrocardiographic changes, coronary blood flow dynamics, cardiac muscle metabolism and left ventricular function, as well as measures to counter these effects and provide for reperfusion in unstable angina and acute myocardial infarction. Technology has expanded the 'eyes' of the observer of these events. The authors use many techniques including ECG recording from surface, endocardium, and intracoronary electrodes; angiographic assessment of coronary flow pattern using digital techniques, as well as doppler flow measurements; biochemical assessment of metabolic products stimulated by ischemia; and digital angiographic and echo doppler assessment of left ventricular function.

Coronary Angioplasty