The incidence of nephrotoxicity occurring with the nonionic contrast agent, iohexol, and the ionic contrast agent, meglumine/sodium diatrizoate, was compared in 1196 patients undergoing cardiac angiography in a prospective, randomized, double-blind multicenter trial. Patients were stratified into four groups: renal insufficiency (RI), diabetes mellitus (DM) both absent (N = 364); RI absent, DM present (N = 318); RI present, DM absent (N = 298); and RI and DM both present (N = 216). Serum creatinine levels were measured at -18 to 24, 0, and 24, 48, and 72 hours following contrast administration. Prophylactic hydration was administered pre- and post-angiography. Acute nephrotoxicity (increase in serum creatinine of > or = 1 mg/dl 48 to 72 hours post-contrast) was observed in 42 (7%) patients receiving diatrizoate compared to 19 (3%) patients receiving iohexol, P < 0.002. Differences in nephrotoxicity between the two contrast groups were confined to patients with RI alone or combined with DM. In a multivariate analysis, baseline serum creatinine, male gender, DM, volume of contrast agent, and RI were independently related to the risk of nephrotoxicity. Patients with RI receiving diatrizoate were 3.3 times as likely to develop acute nephrotoxicity compared to those receiving iohexol. Clinically severe adverse renal events were uncommon (N = 15) and did not differ in incidence between contrast groups (iohexol N = 6; diatrizoate N = 9). In conclusion, in patients undergoing cardiac angiography, only those with pre-existing RI alone or combined with DM are at higher risk for acute contrast nephrotoxicity.(ABSTRACT TRUNCATED AT 250 WORDS)

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Isolated single coronary artery is a rare congenital anomaly occuring in approximately 0.024% of the population. This entity can be diagnosed during life only by coronary angiography. Ten patients with isolated single coronary artery are reported. Based on angiographic analysis, a new classification is proposed, according to the site of origin and anatomical distribution of the branches. Typical angina did not occur with single coronary artery in the absence of coexisting coronary artery disease or aortic stenosis. No correlation was apparent between the type of anomalous patterns and the symptoms of angina.

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Current guidelines and literature on screening for coronary artery calcium for cardiac risk assessment are reviewed for both general and special populations. It is shown that for both general and special populations a zero score excludes most clinically relevant coronary artery disease. The importance of standardization of coronary artery calcium measurements by multidetector CT is discussed.

CT angiography shows promise in the diagnosis of RAS. The accuracy of CT angiography varies with the three-dimensional rendering technique employed.

The velocity of flow and pressure in the venae cavae of four normal conscious subjects was studied. Velocity was measured with a catheter-tip electromagnetic transducer. The effects of respiration, Valsalva and Müller maneuvers, coughing, and exercise were studied. Caval blood velocities during breath holding showed marked cardiac pulsations, being maximal at the time of ventricular systole and minimal or reversed at atrial systole. Peak velocities during ventricular systole ranged from 30 to 45 cm/sec in the inferior, and from 10 to 35 cm/sec in the superior, vena cava. A second diastolic forward flow velocity ranged from 36 to 76% of the systolic peak. During inspiration, velocity transiently increased. Reduction of flow velocity in abdominal breathing and the Müller maneuver is consistent with the formation of a local area of inferior vena caval collapse at the diaphragm. During the Valsalva maneuver, abrupt reduction in caval flow was seen that persisted throughout the strain. There was immediate overshoot when the strain was released. Coughing produced a reduction of flow velocity with backflow in the superior vena cava. In leg exercise, inferior caval flow velocity rose immediately, and it remained high during recovery. Marked respiratory velocity variations with inspiratory increases occurred during and after exercise.

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