bluuebunny/crossref_metadata_2025 huggingface dataset:
Alcohol‐Induced Disruption of Endocrine Signaling
Authors: Ronis Martin J. J. , Wands Jack R. , Badger Thomas M. , De La Monte Suzanne M. , Lang Charles H. , Calissendorff Jan
Published: June 2007

This article contains the proceedings of a symposium at the 2006 ISBRA Meeting in Sydney Australia, organized and cochaired by Martin J. Ronis and Thomas M. Badger. The presentations were (1) Effect of Long‐Term Ethanol Consumption on Liver Injury and Repair, by Jack R. Wands; (2) Alcohol‐Induced Insulin Resistance in Liver: Potential Roles in Regulation of ADH Expression, Ethanol Clearance, and Alcoholic Liver Disease, by Thomas M. Badger; (3) Chronic Gestational Exposure to Ethanol Causes Brain Insulin and Insulin‐Like Growth Factor Resistance, by Suzanne M de la Monte; (4) Disruption of IGF‐1 Signaling in Muscle: A Mechanism Underlying Alcoholic Myopathy, by Charles H. Lang; (5) The Role of Reduced Plasma Estradiol and Impaired Estrogen Signaling in Alcohol‐Induced Bone Loss, by Martin J. Ronis; and (6) Short‐Term Influence of Alcohol on Appetite‐Regulating Hormones in Man, by Jan Calissendorff.
Polyphenolic Grape Extract Inhibits Platelet Activation Through PECAM‐1: An Explanation for the French Paradox
Authors: De Lange Dylan W. , Verhoef Sandra , Gorter Gertie , Kraaijenhagen Rob J. , Van De Wiel Albert , Akkerman Jan‐Willem N.
Published: June 2007

Background: Moderate and prolonged consumption of red wine is associated with decreased cardiovascular morbidity and mortality. Inhibition of platelet functions by ingredients in red wine is thought to be one of the causes. However, the molecular mechanism of this inhibition has remained unexplained.

Materials and Methods: We measured aggregation, changes in cytosolic Ca2+ and tyrosine phosphorylation of the inhibitory receptor platelet endothelial cell adhesion molecule‐1 (PECAM‐1) in platelets stimulated with thrombin receptor (PAR‐1) activating peptide (TRAP) and ADP and investigated the effects of alcohol‐free polyphenolic grape extract (PGE), alcohol, and the polyphenols catechin, epi‐catechin, resveratrol, trans‐resveratrol, and gallic acid.

Results: Polyphenolic grape extract induced dose‐dependent inhibition of TRAP‐induced and ADP‐induced platelet aggregation and Ca2+ mobilization. Inhibition was accompanied by activation of PECAM‐1. Apart from a slight inhibition by catechin, ethanol or other individual polyphenols failed to inhibit aggregation or activate PECAM‐1.

Conclusions: Red wine inhibits platelet functions through its PGE content, which stimulates the inhibitory receptor PECAM‐1, thereby attenuating platelet activation.
Effects of Drivers' License Suspension Policies on Alcohol‐Related Crash Involvement: Long‐Term Follow‐Up in Forty‐Six States
Authors: Wagenaar Alexander C. , Maldonado‐Molina Mildred M.
Published: June 2007

Background: We evaluated the effects of driving under the influence (DUI) mandatory preconviction and postconviction drivers' license suspension laws in each of 46 U.S. states using 1 to 2 decades of long‐term follow‐up data on fatal car crashes. State‐specific results were combined using meta‐analytic techniques, and provide a direct test of the concept of celerity—time between offending behavior and consequent punishment—from deterrence theory.

Methods: Four key outcome measures of monthly fatal alcohol‐related crash involvement were examined using data from January 1976 through December 2002: single‐vehicle nighttime, breath or blood alcohol concentration (BAC)=0.01 to 0.07, BAC=0.08 to 0.14, and BAC≥0.15 g/dL. Missing BAC test data for some individual cases were filled using multiple imputation methods, and consequent increases in standard errors were incorporated into subsequent analyses. Separate ARIMA models were estimated for each state, including controls for state‐specific levels of crash involvement over time due to other factors and effects of other major DUI countermeasures. Estimates were pooled across states using inverse variance weighting methods.

Results: Administrative or preconviction drivers license suspension policies have statistically significant and substantively important effects in reducing alcohol‐related fatal crash involvement by 5%, representing at least 800 lives saved per year in the United States. Moreover, these laws have similar effects on drivers at all drinking levels—from lower‐risk drivers below the legal alcohol limit to drivers at extreme levels of intoxication. In clear contrast, postconviction license suspension policies have no discernable effects.

Conclusions: The effectiveness of a deterrence policy appears to be more strongly affected by celerity—the speed by which punishment is applied after the offending behavior—than by the high severity of the penalty. This finding could be fruitfully applied to other areas of alcohol control policy and laws and regulations in general.
Surface Quality and Long‐term Dimensional Stability of Current Elastomeric Impression Materials after Disinfection
Authors: Walker Mary P. , Rondeau Meagan , Petrie Cynthia , Tasca Amy , Williams Karen
Published: June 2007

Purpose:
The objectives of this investigation were to evaluate the effect of disinfection on surface quality and dimensional stability of more recent, reformulated vinylpolysiloxane (VPS) and polyether (PE) materials.

Methods: Using ANSI/American Dental Association (ADA) specification 19 protocols, 50 impressions of stainless steel dies were made with each material. Ten impressions of each material were randomly assigned to a treatment group: (1) no disinfectant; (2) 10‐minute dual phenol immersion; (3) 1‐hour dual phenol; (4) 10‐minute sodium hypochlorite (NaOCl); and (5) 1‐hour NaOCl. Impression surface quality immediately after disinfection was categorized as smooth/shiny, matte, or wrinkled/sticky. Dimensional stability was evaluated by measuring dimensional accuracy according to specification 19 after 24‐hour, 1‐week, and 2‐week storage at ambient laboratory conditions.

Results: The PE material surface quality was significantly affected (Pearson Chi‐square, p≤ 0.05) by NaOCl with a mottled surface on 30% of the impressions after 10‐minute immersion and a matte/sticky surface on 100% of the PE impressions after 1‐hour immersion. Separate 2‐factor analyses of variance (ANOVA) and Bonferroni post hoc tests of dimensional accuracy within each material indicated a significant difference (p≤ 0.05) between non‐disinfected and disinfected PE impressions, which exhibited expansion. There were also significant differences (p≤ 0.05) in both VPS and PE dimensional accuracy as a function of measurement time related to increasing shrinkage over time in non‐disinfected and disinfected impressions.

Conclusions: Despite PE expansion following disinfection and continued shrinkage of both the non‐disinfected and disinfected VPS and PE impressions over a 2‐week period, all dimensional accuracy measurements met the ADA standard, ≤0.5% dimensional change. Based on this evidence, neither NaOCl nor dual phenol disinfectants used for varying time periods adversely affected the dimensional stability of the more recent formulations of VPS and PE; however, Impregum PentaSoft PE surface quality appeared to be adversely affected by increasing exposure to NaOCl.
Occlusal Changes Following Posterior Tooth Loss in Adults. Part 1: A Study of Clinical Parameters Associated with the Extent and Type of Supraeruption in Unopposed Posterior Teeth
Authors: Craddock Helen L. , Youngson Callum C. , Manogue Michael , Blance Andrew
Published: June 2007

Purpose:
One of the barriers to restoring an edentulous space may be the supraeruption of an unopposed tooth to occupy some or all of the space needed for prosthetic replacement. The aim of this study was to determine the extent and type of supraeruption associated with unopposed posterior teeth and to investigate the relationship between these and oral and patient factors.

Materials and Methods:
Diagnostic casts of 100 patients with an unopposed posterior tooth and of 100 control patients were scanned and analyzed to record the extent of supraeruption, together with other clinical parameters. The type of eruption present was defined for each subject as Periodontal Growth, Active Eruption, or Relative Wear. Generalized Linear Models were developed to examine associations between the extent and type of supraeruption and patient or dental factors. The extent of supraeruption for an individual was modeled to show association between the degree of supraeruption and clinical parameters. Three models were produced to show associations between each type of supraeruption and clinical parameters.

Results:
The mean supraeruption for subjects was 1.68 mm (SD 0.79, range 0 to 3.99 mm) and for controls, 0.24 mm (SD 0.39, range 0 to 1.46 mm). The extent of supraeruption was statistically greater in maxillary unopposed teeth than in mandibular unopposed teeth. Supraeruption was found in 92% of subjects' unopposed teeth.

Conclusions:
A Generalized Linear Model could be produced to demonstrate that the clinical parameters associated with supraeruption are periodontal growth, attachment loss, and the lingual movement of the tooth distal to the extraction site. Three types of supraeruption, which may be present singly, or in combination, can be identified. Active eruption has an association with attachment loss. Periodontal growth has an inverse association with attachment loss, is more prevalent in younger patients, in the maxilla, in premolars, and in females. Relative wear has an association with increasing age and is more prevalent in unopposed mandibular teeth.
The Institutionalization of Alternative Dispute Resolution in the Federal Government
Authors: Nabatchi Tina
Published: June 2007

This article uses resource dependence and institutional theory to examine the implementation of the Administrative Dispute Resolution Acts of 1990 and 1996. The insights from these theories are employed to explain the diffusion of and variation in the application of alternative dispute resolution (ADR) to different programmatic areas. Although agencies have generally complied with the direct requirements of the acts, their intent has not been fully realized. Several factors have complicated the implementation of the ADR Acts, prompting agencies to take different strategic approaches to the application of ADR in programmatic areas. In general, agencies have acquiesced to the use of ADR in employment disputes, compromised on ADR use in contracting and procurement disputes, and avoided ADR use in civil enforcement disputes. Finally, this article evaluates progress toward impact evaluations of the ADR Acts and suggests directions for future research.
Intracoronary Blood Flow Velocity and Transstenotic Pressure Drop in an Awake Human Being During Coronary Vasodilation
Authors: ZIJLSTRA FELIX , SERRUYS PATRICK W.
Published: June 2007

The pressure drop over a coronary stenosis and the intracoronary Doppler blood flow velocity were measured at rest and during coronary vasodilation. We report the first observation that confirms the validity of fluid dynamic equations to describe the hemodynamics of a coronary stenosis based on quantitative arteriography in a human being. (J Interven Cardiol 1988:1:1)
Potential Applications of Lasers in the Management of Cardiovascular Diseases
Authors: LEE GARRETT , CHAN MING C. , REIS ROBERT L. , ARGENAL AGUSTIN J. , LOW REGINALD I. , MASON DEAN T.
Published: June 2007

Since it was first developed, the laser has had applications in medicine and surgery. Continued progress in fiber optics has allowed researchers to explore the potential use of the laser in cardiovascular diseases. Most of the effort has been devoted to building appropriate lasers and delivery systems to recanalize atherosclerotic obstructions of the coronary and peripheral arteries. Early clinical investigations have demonstrated the potential of lasers to remove atherosclerotic plaque during intraoperative bypass surgery and to assist percutaneous transluminal balloon angioplasty. Other investigations into the clinical use of lasers for vascular anastomosis, ablation of refractory ventricular arrhythmias after electrical recording, and palliative treatment of newborn infants with congenital problems hold promise. While early studies and recent technological advances appear encouraging, much more work and improvements are needed before lasers can gain acceptance as a potent clinical tool in the treatment of cardiovascular diseases. (J Interven Cardiol: 1988:1:1)
Coronary Angioplasty of Bifurcational Lesions: Use of Simultaneous Over‐the‐Wire and Probe™ Systems
Authors: GOUDREAU EVELYNE , VETROVEC GEORGE W. , DISCIASCIO GERMANO
Published: June 2007

Different techniques have been used to perform coronary angioplasty of bifurcational lesions. Advantages and disadvantages of the kissing balloon technique, the single guiding‐double wire technique, and the double Probe(tm) technique are reviewed. We describe a new technique for coronary angioplasty of bifurcational lesions through a single guiding catheter that has advantages of both the over‐the‐wire and the Probe(tm) systems.
Electrocardiographic Changes Following Balloon Dilatation of Valvar Pulmonic Stenosis
Authors: RAO P. SYAMASUNDAR , SOLYMAR LASZLO
Published: June 2007

The purpose of this paper was to study the electrocardiographic changes following balloon pulmonary valvuloplasty for pulmonic stenosis and to see if such changes reflect improvement in pulmonary valve gradient following balloon valvuloplasty. Forty‐one patients, ages 7 days to 20 years, underwent balloon valvuloplasty for severe valvar pulmonic stenosis. In 35 of these patients ECGs were available 3 to 34 months (mean 11) following valvuloplasty and were compared with pre‐valvu‐loplasty electrocardiograms. In 30 children with excellent relief of pulmonic stenosis (group I), frontal plane mean QRS vector moved toward the left from 127 ±25° to 81 ±47°as did the horizontal plane mean QRS vector, 88 ± 36° to 27 ±51°. The amplitude of R wave in V1, 19 ± 11.6 mm, and V2, 19.7 ± 12.2 mm, decreased respectively to 9.5 ± 5.9 mm and 11.3 ±6.1 mm. S wave amplitude in V5 and V6 also decreased. The improvement in the electrocardiogram is associated with a decrease in pulmonary valve gradient from 95 ± 50 to 29 ± 23 mm Hg. In five children with significant residual pulmonary valve gradient (group II), the electrocardiograms did not show any significant change. Evaluation of the time course of ECG changes in group I revealed that recognizable electrocardiographic improvement was first observed at 6 months following successful balloon pulmonary valvuloplasty. Normal electrocardiogram suggests minimal residual pulmonary valve gradient while right ventricular hypertrophy suggests significant residual obstruction unless the electrocardiogram was recorded at or before six months following balloon valvuloplasty. These data suggest that electrocardiogram is a good indicator of improvement following balloon pulmonary valvuloplasty. (J. Interven Cardiol 1988:1:3)
Double Balloon Technique for Percutaneous Balloon Pulmonary Valvuloplasty: Comparison with Single Balloon Technique
Authors: RAO P. SYAMASUNDAR. , FAWZY MOHAMMED E.
Published: June 2007

This study was designed to document our results of double balloon pulmonary valvuloplasty and to evaluate if the double balloon technique is preferable to single balloon valvuloplasty in the relief of isolated valvar pulmonic stenosis. Double balloon valvuloplasty in twelve patients reduced the pulmonary valvar gradient from 100.5 ± 28.0 (mean ± SD) to 26.6 ± 12.5 mm Hg (P < 0.001) which remained improved, 17.5 ± 10.2 mm Hg (P < 0.001) at 6 to 14 month follow‐up. Single balloon valvuloplasty with equivalent balloon/pulmonary valve annulus ratios (1.19 ± 0.14 vs 1.19 ± 0.15, P > 0.1) in another 12 patients also reduced (P < 0.001) the gradient from 96.3 ± 40.1 to 28.3 ± 17.3 mm Hg immediately following the procedure which at 6 to 13 month follow‐up was 12.8 ± 9.9 mm Hg. The right ventricular peak systolic pressures (116.6 ± 24.5 vs 113.8 ± 41.5 mm Hg) and pulmonary valvar gradients (100.5 ± 28.0 vs 96.3 ± 40.1 mm Hg) prior to valvuloplasty, residual right ventricular pressures (47.4 ± 12.2 vs 54.3 ± 14.2 mm Hg) and pulmonary valve gradients (26.6 ± 12.5 vs 28.3 ± 17.3 mm Hg) immediately after valvuloplasty, and residual right ventricular pressures (43.1 ± 10.9 vs 41.1 + 12.5 mm Hg) and pulmonary valvar gradients (17.5 ± 10.2 vs 12.8 ± 9.9 mm Hg) on follow‐up were similar (P ± 0.1) in both groups.

These data indicate that results of double balloon valvuloplasty are excellent but not superior to single balloon valvuloplasty. It is suggested that the double balloon valvuloplasty should be used if the pulmonary valve annulus is too large to dilate with a single balloon. There is no need for double balloon valvuloplasty if the pulmonary valve can be dilated with a commercially available single balloon.
Direct Entrainment‐Guided Catheter Fulguration of Atrial Flutter in Man
Authors: SAOUDI N. , MOUTON‐SCHLEIFER D. , CRIBIER A. , LETAC B.
Published: June 2007

Direct catheter fulguration of the reentrant circuit of atrial flutter was performed in a 63‐year‐old patient referred for His bundle ablation. Careful right atrial mapping was performed using standard catheter electrodes. Two zones of fragmented potentials were recorded: one in the low posterior right atrial septum and the other one in the sinus node area. Entrainment of the tachycardia was attempted and achieved, while at the same moment the electrograms of the sinus node area dissociated, thereby excluding it as part of the reentrant circuit. Two shocks of100 and 150 J respectively were delivered in the low postero‐septal area without complication. Seventy weeks of follow‐up were uneventful despite persistence of inducibility of a rapid (non clinical) atrial flutter at late control (day 90). Direct catheter ablation in human atrial flutter seems to be a promising procedure if further studies confirm its efficiency.
Mechanical Rotary Atherectomy: The Effects of Microparticle Embolization on Myocardial Blood Flow and Function
Authors: FRIEDMAN HAROLD Z. , ELLIOTT MARK A. , GOTTLIEB GEOFFREY J. , O'NEILL WILLIAM W.
Published: June 2007

Mechanical rotary atherectomy is a new method for coronary revascularization that may soon serve as an alternative to current angioplasty techniques. Inherent with this procedure, however, are the potentially deleterious effects of microparticle dispersal directly into the coronary bloodstream. To study the immediate cardiac effects, debris created by rotary atherectomy of fresh human cadaver coronary arteries were subselectively injected into the left anterior descending coronary artery of six instrumented, open‐chested dogs. There were no significant changes in heart rate, left ventricular end‐diastolic and systolic blood pressures over a 2‐hour period. Minor reductions in regional myocardial function, mean coronary blood flow and coronary flow reserve were also noted. Arrhythmias did not occur. Histologic examination revealed the absence of intravascular debris. Rare foci of myonecrosis were noted in two dogs within the anteroseptal myocardial segment.
Reinfarction Related to PTCA‐Induced Coronary Embolism after Successful Thrombolytic Therapy
Authors: NIXDORFF UWE , ERBEL RAIMUND , MEYER JÜRGEN
Published: June 2007

Coronary embolism originating from residual thrombotic material is one of the complications arising during acute percutaneous transluminal coronary angioplasty (PTCA) in acute myocardial infarction. This case report describes a symptomatic embolization of the right posterolateral and right posterior descending branch during success‐ful PTCA of a subtotal stenosis of the midright coronary artery after acute inferior myocardial infarction. Typical ECG signs of reinfarction were recorded. We succeeded in recanalizing these branches by superselective thrombolysis and angioplasty.
Comparison of Atrial Leads: Importance of Polarity and Fixation Mechanism
Authors: EMRE ATILA , MCALISTER HUGH , TUZCU E. MURAT , MALONEY JAMES D.
Published: June 2007

To compare the influence of polarity and fixation mechanism on atrial leads, we evaluated acute implantation and 12‐month follow‐up results in 211 patients, 138 male and 73 female, aged 63 ± 14 years, implanted with DDD (210) and AAI (1) pacemakers. Eighty patients had bipolar (B) active fixation (AF) leads (CPI‐4266), 71 had unipolar (U) AF (Medtronic‐6957J), 36 had B passive fixation (PF) (Medtronic‐4512), and 26 had U PF (Medtronic‐4511) leads. Acutely, capture thresholds were higher in the AF than the PF group (BAF: 1.0 ± 0.5 V; UAF: 0.9 ± 0.4 V; BPF: 0.6 ± 0.2 V; UPF: 0.5 ± 0.1V ‐ P < 0.001). The BPF lead acute sensing threshold was superior to the AF leads (P wave sensing for BPF: 3.2 ± 1.5 mV; BAF: 2.2 ± 1.2 mV; UAF: 2.2 ± 1.1 mV ‐ P < 0.003). In both AF and PF groups, lead polarity did not affect pacing and sensing thresholds. The difference in acute capture thresholds between AF and PF leads was abolished prior to discharge, and at subsequent follow‐up over 12 months, no difference in chronic thresholds was observed. During the follow‐up period, the chronic sensing thresholds of BAF leads were superior to the others. There was no significant difference in the complication rates of the four leads. Thus, all four leads proved satisfactory in clinical practice. No major impact of polarity and fixation mechanism was detected.
Laser‐Thermal Recanalization Using Short Interrupted Bursts of Energy in Peripheral Arterial Occlusions
Authors: LEE GARRETT , ARGENAL AGUSTIN J. , WIXSON DAVID , LEE MARSHALL H. , LEE KELVIN K. , KOZINA JOSEPH , MASON DEAN T.
Published: June 2007

The efficacy of a new laser thermal probe is being tested in patients with chronic total occlusion of the ilio‐femoropopliteal arteries. The new probes utilize short interrupted bursts of laser energy while the probe is in direct contact with the obstruction. Ten patients (mean age 68 years) with occlusions had claudication walking one block or less; the mean length of 11 occlusions was 6.5 cm. Angiographic luminal patency and ankle brachial index were evaluated in each patient. Luminal patency (1.0 = no narrowing) increased from 0 to 0.64 ± 0.08 after laser thermal recanalization (P < 0.001), and further increased to 0.88 ± 0.05 after laser‐balloon angioplasty (P < 0.01). Ankle brachial index increased from a baseline of 0.60 ± 0.03 to 0.82 ± 0.03 after laser balloon angioplasty (P < 0.001). No arterial perforation, spasm, thrombosis, or embolism occurred; and there was no damage of guidewire or metal probe of the catheter. These data suggest that short interrupted bursts of thermal energy are effective in recanalizing peripheral vascular occlusions; long‐term evaluation is underway to determine whether such debulking by laser thermal revascularization lowers the late restenosis/reocclusion rate of balloon angioplasty. (J Interven Cardiol 1989:2:4)
Angiographic and Histologic Course after Implantation of Balloon Expandable Intravascular Stents in Miniswine Coronary Arteries: Short‐ and Mid‐Term Observations
Authors: BURGER WOLFRAM. , HARTMANN ANDREAS. , KANDYBA JÖRG. , KEUL HANS‐GEORG. , SIEVERT HORST. , NIEMÖLLER ELISABETH. , SCHNEIDER MARKWARD. , KOBER GISBERT.
Published: June 2007

Sixteen balloon expandable Medtronic Wiktor tantalum stents were implanted in the major coronary arteries of six minipigs, which were maintained on a normal diet and given 500 mg aspirin per day. Angiographic and histologic examinations were performed 6 and 26 weeks after implantation. Angiographically reviewed, stenting increased the inner diameter of the coronary arteries from 2.61 ± 0.44 to 3.02 ± 0.34 mm (n = 16, P ≤ 0.001). Six weeks later, this value was reduced from 2.98 ± 0.35 to 2.33 ± 0.46 mm (n = 9, P ≤ 0.05), and between 6 and 26 weeks, an increase from 2.17 ± 0.44 to 2.93 ± 0.40 mm occurred (n = 6, P ≤ 0.05). Histologic evaluation at 26 weeks after stent implantation revealed an increase of the cross‐sectional area of the total vessel from 4.30 ± 1.09 to 5.50 ± 1.67 mm2 (n = 9; P ≤ 0.01). This was due to widening of the total vessel and intimal proliferation, which amounted to 1.19 ± 0.46 mm2 within the stented segment, as compared to 0.03 ± 0.03 mm2 in control sections (P ≤ 0.01). The areas of free vessel lumen, media muscularis, and adventitia remained unchanged. In 15 of the 16 hislologically examined coronary arteries, the internal elastica was fractured at the site of stent implantation. Twelve stents had also penetrated through the external elastica without evidence of wall hemorrhage. Thirteen out of 16 stents were angiographically followed, of which 12 were patent at the final reangiography. In one animal, acute thrombosis of the stented vessel after guidewire induced coronary artery spasm caused chronic right heart failure due to right ventricular myocardial infarction. Sudden death occurred in another pig 2 hours after successful implantation of three grossly oversized stents (inner vessel diameter: 2.4 ± 0.2 mm, stent diameter 3.2 ± 0.5 mm). Autopsy revealed extensive dissections of the media with subsequent vessel occlusion. It is concluded that Medtronic Wiktor stents can be placed easily, even in more distal or curved coronary arteries. Despite antiaggregational medication, intimal proliferation is observed early after implantation, reaches a maximum at about 6 weeks, and is followed by a regression 26 weeks poststenting. At 26 weeks follow‐up, the free vessel lumen at the stent site was not significantly reduced as compared to control segments. Proper adjustment of internal vessel diameter and stent diameter is necessary to prevent major dissections and thrombotic occlusions.
Management of Major Coronary Artery Dissection Complicating Percutaneous Transluminal Coronary Angioplasty‐Successful Application of Two New Techniques
Authors: MORGAN JOHN M. , CRIPPS TIM R. , BOWKER TIMOTHY. , RICKARDS ANTHONY F.
Published: June 2007

Percutaneous transluminal coronary angioplasty may be complicated by the occurrence of major coronary artery dissection, which may precipitate critical myocardial ischemia, necessitating urgent surgical intervention. We report two cases of massive dissection following angioplasty, in which novel methods were used to stabilize arterial integrity. In the first, laser balloon angioplasty was used to repair the dissection; in the other, a coronary stent was inserted. In both cases, coronary artery patency was achieved with reperfusion of the distal coronary bed, thus avoiding the need for acute surgical intervention. Both patients are free of limiting symptoms at follow‐up.
A Review of Thrombolysis Mortality Trials: ISAM to ASSET
Authors: SCHRÖDER ROLF.
Published: June 2007

Large controlled mortality studies with streptokinase, APSAC or tissue plasminogen activator (tPA) have conclusively shown that thrombolytic therapy within 6 hours after symptom onset improves survival after acute myocardial infarction. There is evidence of benefit even for patients treated between 7–24 hours after pain onset, suggesting that early recanalization of the infarct‐related artery is not the only mechanism by which thrombolysis improves survival. There is no apparent upper age limit for thrombolytic therapy. Serious side effects are generally rare and not age dependent. Inclusion criteria as well as concomittant adjuvant therapy were different in the various trials. Furthermore, the 95% confidence intervals for mortality reduction by different thrombolytic agents are overlapping. To evaluate their relative efficacy and safety direct head‐to‐head comparison is needed.
Intravascular Ultrasound Imaging: Use in Peripheral Laser‐Assisted Angioplasty
Authors: DIETHRICH EDWARD B. , DA CUNHA E SA DIOGO IVENS FERRAZ. , BAHADIR ILHAN. , SANTIAGO OSVALDO.
Published: June 2007

The proliferation of sophisticated endovascular interventions is mandating more definitive and comprehensive documentation of atherosclerotic lesions and the results of the interventional devices used in their removal. A technique with a potential to fulfill these goals, intravascular ultrasound imaging (IVUS), was evaluated against pressure gradients, arteriography, and femoral‐radial indices in 11 patients with stenotic iliac lesions. The two‐dimensional, real‐time scans were useful in measuring pre‐and posttreatment cross‐sectional diameters and luminal areas for procedural assessment. Furthermore, the ultrasound scans clearly identified arterial wall calcifications, iliac veins, soft plague formations, dissections, synthetic graft anastomoses, and intravascular stents, often with definition superior to arteriography. The IVUS technique was useful in selecting interventional therapies, in particular, the need for stent implantation to control intimal flaps. Further, IVUS demonstrated its ability as a substitute for contrast arteriography in a twelfth patient with an iliac stent in whom a protocol‐dictated follow‐up arteriogram was contraindicated.
Reperfusion Adjunctive Therapy: Platelet Active Agents
Authors: WILLERSON JAMES T. , GOLINO PAOLO. , MCNATT JANICE. , YAO SHENG‐KUN. , BUJA L. MAXIMILIAN.
Published: June 2007

Changes in a coronary artery thrombus resulting from platelet activation may affect the speed of thrombolysis and the frequency of reocdusion after thrombolytic therapy. In studies performed in canine models, we have found that selected thromboxane and serotonin receptor antagonists given in combination markedly enhance the thrombolytic effect of tissue plasminogen activator, probably by preventing further platelet activation and their incorporation into a thrombus during thrombolytic therapy. The combination of a thromboxane and serotonin receptor antagonist given with heparin and tissue plasminogen activator is effective in delaying or preventing reocdusion after discontinuation of tissue plasminogen activation in experimental canine models in whom coronary artery thrombosis has been induced by an indwelling copper coil.
Reperfusion Adjunctive Therapy: Heparin
Authors: CAIRNS JOHN A.
Published: June 2007

Heparin therapy for patients who have undergone thrombolytic therapy of acute myocardial infarction is logical, and several trials suggest a benefit. However, in the light of the clear adjuvant benefit of aspirin, and the failure of large clinical trials to demonstrate clinically important benefits of heparin, it is not possible to make sound recommendations as to the clinical value of adjuvant heparin therapy. The possible inadequacies in previous study designs, and the persisting suggestions of beneficial effects from heparin, indicate that further trials are required and will be done to resolve this therapeutic uncertainty.
Modified Fiber Tips for Laser Angioplasty: Mechanisms of Action
Authors: VERDAASDONK RUDOLF M. , VAN LEEUWEN TON G. J. M. , GIJSBERS GEERT H. M. , SPRANGERS RENE L. H. , VAN GEMERT MARTIN J. C. , BORST CORNELIUS.
Published: June 2007

Laser angioplasty with modified fiber tips has become a common procedure for the recanalization of totally occluded peripheral arteries. We evaluated the contribution of optical, thermal, and mechanical effects to the mechanism of recanalization of various probes, theoretically and experimentally. Temperature behavior and tissue penetration were measured in relation to axial force exerted by metal laser probes, and optical contact probes coupled to continuous‐wave and pulsed Nd:YAG lasers. Modified fiber tips only penetrated tissue when the contact surface of the probe exceeded a temperature threshold of about 225°C in the fatty tissue model used. Metal laser probes had to be insulated from a liquid environment to attain this temperature. Optical probes needed to have an absorbing layer of carbonized tissue particles to attain this temperature. Tissue penetration by modified fiber tips was force dependent, especially with optical probes. Since the diameter of the probe was larger than the ablative laser beam, the atraumatic probe had to distend soft tissues mechanically. Because the metal laser probes delivered their energy in all directions, undesired heating in the radial direction has to be reduced by motion. The recanalization mechanism of modified fiber tips will depend on the properties of the obstruction. Sometimes the probes will recanalize the obstruction without the use of laser energy (Dotter effect). Moderate heating of the tissue by either direct absorption of light, or by heat conduction from the heated surface of the probe, may help to remodel the obstruction. Tissue temperatures around 100°C will vaporize the water compound, and temperatures higher than 225°C will ablate the solid compounds of the tissue creating a channel. The present unsteerable probes will not penetrate heavily calcified obstructions. Calcific deposits may deflect the probe into the wall with the risk of perforation.
The Role of a Third and Possible Fourth Coronary Angioplasty for Recurrent Stenosis
Authors: IANNONE LIBERATO A. , BROWN THOMAS M. , WICKEMEYER WILLIAM J. , ROUGH RANDOLPH R. , MCGAUGHEY MARK D. , GORDON DAVID F.
Published: June 2007

From 1980 to 1985, 1,179 patients underwent percutaneous transluminal coronary angioplasty (PTCA) for the first time. Of these, 92 (7.8%) underwent a second PTCA, 25 (2.1%) a third, and 5 (0.4%) a fourth PTCA of the same vessel and site of the initial stenosis. Success rates for these groups were 78%, 87%, 88%, and 100%, respectively. The left anterior descending coronary artery (LAD) was involved in 14 (56%), the right coronary artery (RCA) in 9 (36%), and the circumflex coronary artery (CX) in 2 (8%). There were no deaths or emergency surgery due to the third and fourth PTCA. Follow‐up after the last PTCA indicated symptomatic relief and an improvement in Canadian Cardiovascular Society functional class (CAHA) along with an increase in the exercise time on a standard Bruce stress test. We conclude that a third or fourth PTCA provides a safe and effective therapy for recurrent stenosis.
Dynamic Coronary Thrombosis: A Possible Cause of Prinzmetal's Variant Angina
Authors: KARIM AMIN H. , CHAHINE ROBERT A. , RAIZNER ALBERT E.
Published: June 2007

Two patients presented with features typical of Prinzmetal's variant angina: recurrent episodes of chest discomfort at rest associated with transient ST segment elevation. Episodes of recurrent ischemia persisted despite treatment with intravenous nitroglycerin. Coronary arteriography disclosed a high grade stenotic lesion and intracoronary thrombus in both patients. Coronary spasm was not demonstrated. These observations suggest that “dynamic thrombosis” may have a more important role than heretofore recognized in some patients with Prinzmetal's variant angina.
Recanalization of Chronic Coronary Occlusions by Low Speed Rotational Angioplasty (ROTACS)
Authors: KALTENBACH MARTIN , VALLBRACHT CHRISTIAN , HARTMANN ANDREAS
Published: June 2007

From 1988 to 1990 chronic coronary occlusions were treated with a newly developed slowly rotating angioplasty system (ROTACS), which is designed for atraumatic passage of arterial obstructions. In all 152 patients (mean age 55 years, ranging from 29 to 78 years) attempts to recanalize the coronary occlusion with conventional guidewire systems had failed. In 74/152 patients the age of the occlusion could be estimated because of a previous angiogram or clinical event. It ranged from 1–192 months (median 6 months, mean value 14 months; in 20% of patients it was 1–3, in 37% 4–6, in 28% 7–12, and in 15% > 12 months). The occlusion was localized in the right coronary artery (RCA) in 86 cases, in the left anterior descending coronary artery (LAD) in 37 cases, and in the circumflex branch of the left coronary artery in 17 cases. Eleven bypass occlusions were treated. One patient had a LAD and RCA occlusion. Out of 152 patients 84 could be recanalized. The success rate rose with experience from 30% to 60%. It was 55% in the LAD, 52% in the RCA, 70% in the circumflex branch, and 63% in bypass grafts. The success rate in relation to the age of the occlusion was 93% in occlusions of 1–3 month duration, 74% in occlusions of 4–6 months duration, 52% in occlusions of 6–12 months duration, and 8% in occlusions older than 12 months. Seventy‐six of the successfully treated patients underwent follow‐up angiography after 4 months. In 56/76 (74%) the vessel remained open. Twenty‐two patients (29%) had restenosis that was successfully dilated in 21 patients. Twenty patients (26%) had reocclusion. Thus, the angiographically determined long‐term success rate was 72%. Emergency operation was necessary in two patients in whom reopening of the LAD was attempted although the occlusion was located directly at the take‐off of the LAD from the left main. Since this type of occlusion was consequently considered a contraindication, no further serious complications occurred. There was one myocardial infarction, no death, no vessel wall perforation or other complications in the 152 patients. It is concluded that low speed ROTACS is a safe technique that can be applied in chronic coronary occlusions even if the duration of occlusion exceeds 6 months. (J Interven Cardiol 1991; 4:15–165)
Peripheral Laser Angioplasty with Sapphire Tip
Authors: FOURRIER JEAN‐LOUIS , VAN FRACHEN BÉATRICE , HENRI MICHEL , LEFEBVRE JEAN‐MARIE , BRUNETAUD JEAN‐MARC , BERTRAND MICHEL E.
Published: June 2007

To improve the result of peripheral laser recanalization (less perforation with wider tunnels of vaporization), we used the technique of sapphire laser angioplasty, A Nd: YAG laser with continuous emission was connected to a catheter with a 600 †m fiber and a sapphire probe to its extremity (1.8–3 mm in diameter). Treatment was performed on 127 patients with severe stenosis or occlusion of peripheral arteries (iliac, femoral, or popliteal arteries). Recanalization was obtained in 102 cases (80%) and was further embellished by balloon dilatation. The rate of success decreased proportionally with the length of occlusions (93% for 3 cm, 33% for 15 cm and more). Most failures were due to wall perforation or wall entry of the probe; passage of the sapphire tip was rarely blocked by the occlusion. At follow‐up, 26.4% of arteries were reoccluded after 2 months. In conclusion: laser angioplasty with a sapphire tip can totally recanalize occluded arteries with low rate of failure and complications.
Hemodynamic and Metabolic Observations Associated with Intracoronary Stenting for Acute Closure Following Percutaneous Transluminal Coronary Angioplasty
Authors: DE SCHEERDER IVAN K. , TUCCILLO BERNARDINO , STRAUSS BRADLEY H. , DE FEYTER PIM J. , SERRUYS PATRICK W.
Published: June 2007

Emergency stent implantation appears to be an effective method for restoring antegrade flow in case of an abrupt coronary occlusion during percutaneous transluminal coronary angioplasty (PTCA). In this case report, hemodynamic and metabolic changes throughout abrupt coronary closure and stent implantation were followed in order to study the efficacy of this bail out technique in restoring metabolic and hemodynamic disturbances due to acute coronary occlusion.
Early tPA Treatment and Aeromedical Transport of Patients with Acute Myocardial Infarction
Authors: SPANGLER DANIEL E. , ROGERS WILLIAM J. , GORE JOEL M. , GRIFFITH MICKIE , MASKE LARRY E. , MORGAN TERRY E. , CORRAO JEANNE
Published: June 2007

Over a 2‐year period 192 patients with acute myocardial infarction (AMI) were transported by helicopter and treated with recombinant tissue‐plasminogen activator (tPA). All patients were entered into the Thrombolysis in Myocardial Infarction‐Phase II (TIMI II) trial. Eighty‐two of these patients were treated with tPA after aeromedical transport to a tertiary care center. One hundred ten patients had tPA treatment initiated by the flight crew prior to transport. The flight crews initiated therapy 28 ± 11 minutes after arrival at the sending hospital. The post‐flight treated patients received the tPA bolus 82 ± 20 minutes after arrival at the sending hospital (P < .0001), and 41 ± 18 minutes after arrival at the receiving hospital (P < .0001). Based on enzyme and electrocardiographic changes, all patients in the study had a confirmed diagnosis of AMI before discharge. Patients with inferior myocardial infarction (MI) treated with tPA in‐flight were more likely to suffer from bradycardia and hypotension requiring atropine injection during transport than the post‐flight treated patients or inflight treated patients with anterior MI. There was no in‐flight mortality in either group. Our experience indicates that patients with AMI can be transported safely during tPA therapy. Also, a trained team whose sole responsibility is the early evaluation and initiation of therapy in a patient with AMI can function as accurately and significantly more rapidly than tertiary care emergency department and ICU personnel following identical protocols.
Thrombolysis for Acute Myocardial Infarction: Making Sense of The Clinical Trials Data
Authors: ANDERSON JEFFREY L.
Published: June 2007

Trials during the 1980s established that thrombolytic therapy restores coronary blood flow rapidly and reduces mortality compared to control or placebo therapy in acute myocardial infarction. Comparative studies have generated controversy, however, in that the newer agents tissue plasminogen activator (tPA) and anistreplase (APSAC), shown to open arteries more rapidly than streptokinase (SK), achieve no greater mortality reductions. In these trials, tPA may have been disadvantaged because adjunctive IV heparin therapy was not given. This possibility is being explored in the Global Utilization of Streptokinase and tPA for Occluded Coronary Arteries (GUSTO) study. However, heparin may not entirely explain the discrepancy because (1) among patients in International Studies of Infarct Survival (ISIS‐3) given IV heparin out of protocol, no difference in mortality between tPA and SK was observed; (2) reinfarction was actually slightly less after tPA; and (3) APSAC, longer acting and more efficient than SK and not requiring early IV heparin, achieved no greater mortality reductions. Another explanation for the discrepancy between 90‐minute patency and mortality effects among agents is that benefit in the usual time frame of treatment (2–6 hours after onset of symptoms) depends more on diastolic effects (improved healing with preserved diastolic size, shape) than on systolic effects (reduction in infarct size) and is less time‐dependent. A similar survival outcome is then consistent with the observation that all three agents lead to similar plateau patency rates at ≥ 3 hours. Prehospital throtnbolysis trials are exploring the possibility that greater functional and mortality benefits are associated with therapy given very early (within 1–2 hours). Differential benefits might be seen when regimens with differing thrombolytic efficiencies are given within 1–2 hours of symptom onset, but this possibility must be established by direct comparative trials. Future trials should emphasize improved myocardial salvage by more rapid delivery of thrombolytic therapy as well as the use of more efficient thrombolytic regimens.
Partial Anomalous Pulmonary Venous Return with Intact Atrial Septum
Authors: JOSEPH A. , TALLEY J.D. , KUPERSMITH J.
Published: June 2007

Partial anomalous pulmonary venous connection in association with an intact atrial septum is uncommonly encountered in adults. Symptoms may result if the single anomalously draining vein results in elevation of right‐sided heart pressures, enlargement of these chambers, and pulmonary hypertension. The condition is clinically indistinguishable from an atrial septal defect of the ostium secundum type and often requires cardiac catheterization with oximetry, selective dye dilution curves, and angiography of the pulmonary veins for diagnosis. Correction of the abnormality surgically is associated with mini‐mum morbidity and mortality, and often results in the complete resolution of symptoms and signs of right‐sided hemodynamic overload.
Development of a Polymer Endovascular Prosthesis and its Implantation in Porcine Arteries
Authors: van der GIESSEN WILLEM J. , SLAGER CORNELIS J. , VAN BEUSEKOM HELEEN M.M. , VAN INGEN SCHENAU DORETTE S. , HUIJTS RUUD A. , SCHUURBIERS JOHAN C. , de KLEIN WILLEM J. , SERRUYS PATRICK W. , VERDOUW PIETER D.
Published: June 2007

A polyethylene‐terephthalate braided mesh stent has been developed for application in the (coronary) arterial tree. In vitro measurements showed that the radial pressure delivered by this device was in the same range as that of a stainless steel stent. Hysteresis‐like behavior, however, occurred after constraining the polyester stent for a period of only 15 minutes on a delivery system for percutaneous implantation. This implies that the polymer stent must be mounted on this delivery system immediately before the placement procedure, and that either a diameter in the unconstrained condition must be selected, which is considerably larger than the diameter of the target vessel, or stent expansion has to be enhanced by balloon expansion. Taking into account the results obtained during the in vitro studies, we investigated the angiographic patency and histologic features after implantation of this polyester stent in peripheral arteries of pigs. In four animals eight stents were placed. Except for heparin during the implantation procedure only, antithrombotic or antiplatelet drugs were not administered. After 4 weeks repeat angiography was performed. Angiography revealed that five of the six correctly placed stents were patent. At autopsy, two additional patent stents proved to be located in the aortic bifurcation, probably due to failure of the delivery system. Quantitative assessment showed that the mean luminal diameters at the site of stent placement were 3.3 ± 0.2 mm before, 3.2 ± 0.2 mm immediately after, and 3.1 ± 0.3 mm at 4 weeks after implantation. Histology demonstrated an inflammatory reaction of variable severity around the stent fibers. Quantitative histologic measurements showed that the thickness of the neointima was 114 ± 38 μm after 4 weeks. In conclusion, polyester stents can be constructed with mechanical properties similar to stainless steel stents. Hysteresis‐like behavior of polyester stents, however, influences the selection of the nominal stent diameter as well as the forces exerted to the vessel wall. After implantation in porcine peripheral arteries, five of six correctly placed stents were patent at 4 weeks. The extent of neointimal proliferation was similar to that observed after placement of metal stents in swine, despite the presence of a more pronounced inflammatory reaction.