: The benzimidazol analogue BM 14.478 is a phosphodiesterase inhibitor with both vasodilator and positive inotropic properties. Hemodynamic parameters and plasma hormone levels of 8 patients (1 female, 7 male) with chronic congestive heart failure NYHA Classes II‐IV (1 patient with coronary artery disease, 7 patients with primary dilated cardiomyopathy) were assessed before and until 6 h after the intravenous application of 1.0 mg BM 14.478. There was a significant decrease of mean pulmonary artery pressure (28±11 vs. 23±11 mmHg; p>0.05), mean right atrial pressure (8.6±5.2 vs. 5.0±4.7 mmHg; p>0.02), and systemic vascular resistance (1651±484 vs. 1206±252 dynes$$s$$cm–5; p>0.05) as early as 10 min after injection of BM 14.478. Pulmonary vascular resistance also was reduced (128±86 vs. 61±39 dynes$$s$$cm–5, 30 min after injection; p>0.02). Simultaneously there was a significant increase of cardiac index (2.3±0.7 vs. 3.1±0.8 1$$min–5$$m–2, 10 min after injection; p>0.02), and stroke volume index (28.8±11.7 vs. 33.9±8.5 ml$$min–1$$m–2; 30 min after injection; p>0.05). Although mean heart rate did not change significantly, some patients reacted with a transient increase. There was also a slight but insignificant increase of the double product. No serious side effects were observed. The hemodynamic improvement was followed by a delayed reduction of plasma levels of epinephrine (51±20 vs. 41±21 pg/ml; p>0.02; 30 min after injection) and atrial natriuretic peptide (229±283 vs. 121±168 pg/ml; p>0.05; 1 h after injection). Mean levels of plasma norepinephrine, however, did not change significantly and individual responses showed large variations, which could not be predicted by the behavior of the hemodynamic parameters. Three of eight patients (2 of these with elevated baseline filling pressures) even showed a marked increase of plasma norepinephrine levels after BM 14.478. Response of plasma renin activity and plasma vasopressin levels to BM 14.478 also was heterogeneous. According to the results of this study, acute administration of the phosphodiesterase inhibitor BM 14.478 has an immediate beneficial hemodynamic effect in patients with severe congestive heart failure by reducing both preload and afterload, and by increasing cardiac index and stroke volume. However, this improvement of hemodynamic parameters is not necessarily accompanied by a favorable short‐term response of plasma hormones, and therefore does not allow any conclusions on survival of these patients.

To characterise the clinical usefulness of serial myocardial scintigraphy with iodine-123 phenylpentadecanoic acid (IPPA) in comparison with thallium-201, dual-isotope investigations were performed in 41 patients with angiographically documented coronary artery disease. Both tracers were administered simultaneously during symptom-limited ergometry. Planar scintigrams were acquired immediately after stress, and delayed imaging was performed after 1 h for IPPA and 4 h for 201Tl. Scintigrams were evaluated both qualitatively and quantitatively using a newly developed algorithm for automated image superposition. Initial myocardial uptake of both tracers was closely correlated (r = 0.75, p < 0.001). Both tracers also revealed a similar sensitivity for the identification of individual coronary artery stenoses > or = 75% (IP-PA: 70.0%, 201Tl: 66.3%, P = NS) with identical specificity (69.8%). The number of persistent defects, however, was significantly higher with IPPA (P = 0.021), suggesting that visual analysis of serial IPPA scintigrams may overestimate the presence of myocardial scar tissue. On the other hand, previous Q wave myocardial infarction was associated with a decreased regional IPPA clearance (29% +/- 11% vs 44% +/- 11% in normal myocardium, P < 0.05). The data indicate that serial myocardial scintigraphy with IPPA is essentially as sensitive as scintigraphy with 201Tl for the detection of stress-induced perfusion abnormalities. Quantitative analysis of myocardial IPPA kinetics, however, is required for the evaluation of tissue viability.

Iodine-123-labeled phenylpentadecanoic acid (IPPA) has now been commercially available for several years as a tracer to investigate the metabolic status of the myocardium and perfusion in a single investigation. The authors of the paper [1] compared the usefulness of the IPPA fatty acid analogue with that of thallium-201 in one investigation (dual isotope) at maximal, symptomlimited exercise in patients with coronary artery disease (CAD). The main finding of their study was a significantly greater number of persistent defects in the IPPA scans compared to the 2°iT1 scans.We wish to raise several objections to the study protocol, the results, and the conclusions drawn by the authors.Maximal stress would be expected to result in high lactate serum levels, leading to typical metabolic changes in the myocardium which influence IPPA uptake and metabolism:1. The myocardium will shift to lactate as the preferential source of energy production [2].2. Fatty acid oxidation, even in normal perfused myocardial areas, will be prolonged because of the preferential esterification of IPPA into the lipid storage pools [31.3. In this situation uptake will be diminished, especially in ischaemic zones, with increased "backdiffusion" of unmetabolized IPPA highest in ischaemic myocardial regions [4, 5].These factors lead to diminished net uptake, especially in ischaemic zones, which would be expected to result in persistent defects, although these myocardial segments might be viable. Thus, there is no way to meet the demands for these two tracers in a single investigation because maximal stress is required for 2°1T1 studies to decrease flow in regions supplied by stenotic arteries as much as possible, whereas submaximal exercise (or even rest) is required for IPPA studies to maintain the serum lactate level as low as possible, at least if semiquantification of the tracer kinetics is the aim. The authors surprisingly mentioned in the discussion that their results might be influenced by serum levels of competing substrates but did not measure these completely, although routine laboratory methods are available. It is thus our opinion that many of the results and much of thediscussion remain purely speculative, and that the unexpected results might be explained simply by the investigation protocol and thus do not invalidate the clinical usefulness of IPPA scintigraphy.There are some further comments to be made on this paper:1. The authors stated that for a single-photon emission tomography (SPET) study a 20-min rotation time is mandatory and that due to the short myocardial halflife, IPPA SPET is unreliable. These statements are objectively incorrect because the tracer kinetics have been found not to be linear early after administration [5] and we were able to substantiate this experimental finding in patients [7]; consequently sequential IPPA SPET to semiquantitate tracer kinetics is correlated to coronary artery disease with high sensitivity and specificity [8].2. It is not clear what limiting effect the reconstruction algorithm of SPET...

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Systems based on the Archium Digital Cardiac System architecture are providing filmless operation for cardiac catheterization departments in over 80 institutions today. Filmless operation provides direct cost savings from the elimination of cine film as well as its development and management. In addition to these savings, benefits are being realized from productivity associated with changes in the workflow in the department. Image quality and processing capability consistent with the image quality and processing available in the cath lab have proven to be key components in changing workflow and improving efficiency. Solutions are now available which can deliver this level of performance for most departments including multiple lab departments with cath labs from different manufacturers. With Archium, physician productivity can be enhanced with the immediate availability of studies outside the lab and the ability to consult online. Cath lab turnover can be improved significantly. Staff productivity is realized from improved image management as well. The Archium's modular architecture has already accommodated system evolution without obsolescence of existing systems.