Search

In 302 consecutively patients fibrinogen (Clauss method) and leucocyte count were related to the angiographic and clinical degree of coronary atherosclerosis. Fibrinogen (mg/dl) was statistically higher compared to control (C, 267 +/- 55) in patients with one-vessel disease (1-vd (306 +/- 67), 2-vd (331 +/- 73), and 3-vd (328 +/- 62)). Patients with coronary sclerosis (Scl, luminal irregularities and/or stenosis under 50%) showed a tendency to higher fibrinogen levels (291 +/- 58) as compared to controls. Leucocyte count (10(9)/L) compared to C (6.7 +/- 1.8) was significantly higher in 1-vd (7.6 +/- 2.0) and 2-vd (7.6 +/- 1.9). A subgroup analysis was performed with 100 patients having severe forms of angina pectoris (AP III according to the CCS classification, unstable angina). Hundred-sixteen patients with unstable angina (390 +/- 79), particularly with angina at rest during the last 48 h were characterized by the highest fibrinogen values (423 +/- 89, class III B/C Braunwald). Leucocyte count in patients with stable angina (7.2 +/- 1.4) and angina at rest (9.3 +/- 2.7) was significantly higher as compared to control (6.7 +/- 1.8). Hyperfibrinogenemia and relative leucocytosis correlate with the angiographic and clinical extent of coronary artery disease and may offer evidence of a higher degree of thrombogenesis associated with components of inflammation.

Electrophysiological effects of intracoronarily administered contrast media have been documented in 12 thoracotomized dogs at the cellular level by use of a modified microelectrode technique. Injections (n = 63) of 4 different contrast media uniformly led to a temporary cellular hyperpolarisation of the resting potential and prolongation of the action potential. Additional experiments with intracoronary injections of several electrolyte solutions indicate that the observed effects can be explained by contrast-induced changes in the extracellular electrolyte concentrations, mainly by a local deficiency of potassium ions and an excess of sodium ions. The significance of the findings for mechanisms underlying ECG-changes and ventricular arrhythmia by radiographic contrast media will be discussed.

The advantages of a new low osmolality contrast medium (sodium meglumine ioxaglate) in clinical coronary angiography are demonstrated at two groups of patients in comparison to sodium meglumine diatrizoate. One group included patients undergoing diagnostic angiography in chronic state of CHD, the other during diagnosis and therapy (intracoronary lysis) in state of acute myocardial infarction. Injection of the low osmolality contrast material was followed in both groups by significant reduction of pressure drop and cardiac slowing. In both groups there was also a reduction of changes in ECG compared to side effects of the conventional contrast material.

In 16 patients with CAD, hemodynamic and electrophysiologic side effects were examined following selective coronary artery injections with Urografin 76%, a commonly used ionic contrast medium. A Millar transducer tipped catheter was placed in the left ventricle for continuous pressure recording also during injections. The unmodified contrast medium decreases peak left ventricular pressure (-22 +/- 8%) and dp/dt max (-27 +/- 13%) markedly at injection. With added calcium (22.5 mEq/l) this cardiodepressive reaction becomes diminished to -15 +/- 7% and -13 +/- 8% respectively with high significance (p < 0.001). This positive effect is even more marked using higher volumes of contrast material for injection. In contrast to animal experiments, calcium did not completely compensate the negative inotropic reaction even in higher concentration (33.75 mEq/l). The marked sinus slowing (-29 +/- 14%)--observed in patients and not influenced by the calcium addition--has an additional effect in the sense of a "negative frequency-inotropism" and is responsible for the residual cardiodepressive reaction. An influence on electrophysiologic side reactions can also be observed with added calcium but only in injections with higher volumes of contrast medium. QT-elongation, T-wave changes are reduced significantly. We did not see any unfavorable reactions caused by added calcium. The cardiodepressive side effects on the contractile force by commonly used ionic contrast media can be reduced by adding calcium in the above-mentioned concentration. This may be helpful when studying high risk patients and using high injection volumes.

An animal experimental study on seven thoracotomized dogs was designed to investigate the effects of intracoronarily injected sodium meglumine diatrizoate on myocardial electrophysiology and to evaluate the contribution of the corresponding changes of electrolyte levels in coronary blood. For this purpose the effects of alterations in the Na+-, K+- and Ca++-concentrations in coronary blood were studied separately by intracoronarily injected model solutions. Membrane potentials were recorded from the left ventricular myocardium by a modified microelectrode technique which is applicable to the beating and blood perfused heart in situ. Following selective coronary arteriography there was a temporary hyperpolarization of resting potentials and a prolongation of action potentials which may be explained by a contrast-induced local deficiency of potassium and calcium ions and by a relative prevalence of sodium ions in coronary blood. In selective coronary arteriography the synchronicity of cardiac excitation is disturbed by the regional prolongation of action potentials, which may induce ventricular arrhythmias.

The cardiotoxicity of commonly used contrast media such as sodium methylglucamine diatrizoate is related to nonphysiologic concentrations of ions and high osmolality. Following injection there is an excessive decrease in ambient calcium which disturbs the extracellular Na+/Ca2+ ratio and results in myocardial depression. In animal studies (anesthetized, intact mongrel dogs) this cardiodepressive effect could be fully compensated by adding 22.5 mEq/1 of ionic calcium to the contrast medium. In 16 patients studied for coronary artery disease (CAD) 72 injections of sodium methylglucamine diatrizoate, mainly in the left coronary artery, were thoroughly investigated. There was marked depression of left ventricular pressure (-22%) and (dP/dt)max (-27%), and marked heart rate slowing (-29%). Added calcium in the concentration cited reduced significantly (p < 0.001) the myocardial depression to -15% and -13%, respectively, but did not completely compensate it. The heart rate slowing was not altered significantly. It was concluded that the addition of calcium may be helpful when studying high-risk patients and using high injection volumes.