Relationship between para-aminohippurate secretion and cellular morphology in rabbit proximal tubules.

Previous studies in the mammalian proximal tubule have suggested that para-aminohippurate (PAH) secretion is approximately threefold greater in the straight segment, or pars recta, than in the convoluted segment, or pars convoluta. However, the possibility that the site of maximal PAH secretion might be related better to particular tubule segments as identified by cell type had not been explored. In addition, the presence or absence of differences in PAH secretion between morphologically identical regions of superficial (SF) vs. juxtamedullary (JM) proximal tubules has not been examined. These issues were studied using a combination of histologic methods and measurement of [(3)H]PAH secretion in isolated perfused tubules. Measurements of microdissected SF and JM proximal tubules from young and adult rabbits revealed that SF proximal tubules were slightly but significantly longer than JM tubules ([young rabbits: SF, 8.69+/-SE 0.14 mm vs. JM, 7.97+/-SE 0.13 mm; P < 0.01] [adult rabbits: SF, 10.61+/-SE 0.28 mm; JM, 9.17+/-SE 0.19 mm; P < 0.001]). Light and electron microscopy revealed three sequential segments (S(1), S(2), and S(3)) along the length of SF and JM proximal tubules as defined by cell type. PAH secretion was measured in each of these three segments by the isolated perfused tubule technique. Net PAH secretion in fmol/mm per min in SF proximal tubules was: S(1), 281+/-SE 21; S(2), 1,508+/-SE 104; S(3), 318+/-SE 46. Corresponding values in JM proximal tubules were 353+/-SE 31, 1,391+/-SE 72, and 188+/-SE 23. Net PAH secretion did not differ between comparable segments of SF and JM proximal tubules. It is concluded that differences in PAH secretion along the proximal tubule correlate best with cell type rather than the arbitrary division of the proximal tubule into pars convoluta and pars recta according to its external configuration. Evidence of functional heterogeneity between comparable segments of SF and JM proximal tubules was not observed.

Final results of the Can Routine Ultrasound Influence Stent Expansion (CRUISE) study.

BACKGROUND: Intravascular ultrasound (IVUS) can assess stent geometry more accurately than angiography. Several studies have demonstrated that the degree of stent expansion as measured by IVUS directly correlated to clinical outcome. However, it is unclear if routine ultrasound guidance of stent implantation improves clinical outcome as compared with angiographic guidance alone. METHODS AND RESULTS: The CRUISE (Can Routine Ultrasound Influence Stent Expansion) study, a multicenter study IVUS substudy of the Stent Anti-thrombotic Regimen Study, was designed to assess the impact of IVUS on stent deployment in the high-pressure era. Nine centers were prospectively assigned to stent deployment with the use of ultrasound guidance and 7 centers to angiographic guidance alone with documentary (blinded) IVUS at the conclusion of the procedure. A total of 525 patients were enrolled with completed quantitative coronary angiography, quantitative coronary ultrasound, and clinical events adjudicated at 9 months for 499 patients. The IVUS-guided group had a larger minimal lumen diameter (2.9+/-0.4 versus 2.7+/-0. 5 mm, P<0.001) by quantitative coronary angiography and a larger minimal stent area (7.78+/-1.72 versus 7.06+/-2.13 mm(2), P<0.001) by quantitative coronary ultrasound. Target vessel revascularization, defined as clinically driven repeat interventional or surgical therapy of the index vessel at 9 month-follow-up, occurred significantly less frequently in the IVUS-guided group (8.5% versus 15.3%, P<0.05; relative reduction of 44%). CONCLUSIONS: These data suggest that ultrasound guidance of stent implantation may result in more effective stent expansion compared with angiographic guidance alone.

Milrinone in congestive heart failure: acute and chronic hemodynamic and clinical evaluation.

Acute and chronic hemodynamic and clinical responses to milrinone, a new oral inotrope-vasodilator agent, were evaluated prospectively in 37 patients with severe congestive heart failure. The majority of patients (n = 31) had not responded to prior vasodilator therapy, with a substantial number (n = 8) requiring intravenous inotropic support at the time of initial study. All patients showed acute hemodynamic improvement with oral milrinone, and an optimal maintenance dose was chosen for each patient during dose-ranging studies (average dose 48 mg/day). Milrinone was discontinued before follow-up hemodynamic study in 12 patients (because of worsening congestive heart failure in 6 patients, sudden death in 3 patients, arrhythmia in 1 patient and refusal by 2 patients). Hemodynamic effects of milrinone both acutely and after chronic therapy (average 37 days) were compared in the remaining 25 patients. Acutely, mean cardiac index increased from 1.9 +/- 0.5 to 2.5 +/- 0.5 liters/min per m2 (p less than 0.001), and mean pulmonary capillary wedge pressure decreased from 28 +/- 9 to 18 +/- 8 mm Hg (p less than 0.001). When oral milrinone was readministered after chronic therapy, mean cardiac index increased from 1.9 +/- 0.5 to 2.5 +/- 1.7 liters/min per m2 (p less than 0.001), and pulmonary capillary wedge pressure decreased from 27 +/- 8 to 20 +/- 8 mm Hg (p less than 0.001) at 1 hour. New York Heart Association functional class improved in 18 of the 25 patients treated over a long-term period (mean 5.5 +/- 2.3 months).(ABSTRACT TRUNCATED AT 250 WORDS)

Survival and cardiac event rates in the first year after emergency coronary angioplasty for acute myocardial infarction.

One year survival and event-free survival rates were analyzed in 342 patients with acute myocardial infarction who were consecutively enrolled in a treatment protocol of early intravenous thrombolytic therapy followed by emergency coronary angioplasty. Ninety-four percent of the patients achieved successful reperfusion, including 4% with failed angioplasty whose perfusion was maintained by means of a reperfusion catheter before emergency bypass surgery. The procedural mortality rate was 1.2% and the total in-hospital mortality rate was 11%. Ninety-two percent of surviving nonsurgical patients who underwent repeat cardiac catheterization were discharged from the hospital with an open infarct-related artery. The related cumulative 1 year survival rate for all patients managed with this treatment strategy was 87%, and the cardiac event-free survival rate was 84%. The 1 year survival for hospital survivors was 98% and the infarct-free survival rate was 94%. Multivariable analysis identified the following factors as independent predictors of subsequent cardiovascular death: cardiogenic shock, greater age, lower ejection fraction, female gender and a closed infarct-related vessel on the initial coronary angiogram. Among patients with cardiogenic shock, despite a 42% in-hospital mortality rate, only 4% died during the first year after hospital discharge. Similarly, the in-hospital and 1 year postdischarge mortality rates were 19 and 4%, respectively, for patients with an initial ejection fraction less than 40, and 25 and 3%, respectively, for patients greater than 65 years. An aggressive treatment strategy including early thrombolytic therapy, emergency cardiac catheterization, coronary angioplasty and, when necessary, bypass surgery resulted in a high rate of infarct vessel patency.(ABSTRACT TRUNCATED AT 250 WORDS)

Late restenosis after emergent coronary angioplasty for acute myocardial infarction: comparison with elective coronary angioplasty.

The late restenosis rate after emergent percutaneous transluminal coronary angioplasty for acute myocardial infarction was assessed by performing outpatient follow-up cardiac catheterization in 79 (87%) of 91 consecutive patients who had been discharged from the hospital with a successful coronary angioplasty. The majority of patients (90%) received high dose intravenous thrombolytic therapy with streptokinase in addition to angioplasty. Similar follow-up data were obtained in 206 (90%) of 228 consecutive patients who had successful elective angioplasty during the same period. The interval from angioplasty to follow-up was 28 +/- 9 weeks for the myocardial infarction group and 30 +/- 11 weeks for the elective group. Baseline clinical variables were similar for both the myocardial infarction and elective groups except for a higher percentage of men in the infarction group (81 versus 63%, p = 0.001). The number of coronary lesions undergoing angioplasty and the incidence of intimal dissection were similar, but multivessel angioplasty was more common in the elective group (13 versus 4%, p = 0.02). The rate of in-hospital reocclusion was higher in the patients receiving angioplasty for myocardial infarction (13 versus 2%, p = 0.0001). At the time of late follow-up after hospital discharge, the patients with myocardial infarction were more often asymptomatic (79 versus 55%, p = 0.0001), and the rate of angiographic coronary restenosis was lower for the infarction group both overall (19 versus 35%, p = 0.006) and when multivessel angioplasty patients were excluded (19 versus 33%, p = 0.01).(ABSTRACT TRUNCATED AT 250 WORDS)

Remodeling after directional coronary atherectomy (with and without adjunct percutaneous transluminal coronary angioplasty): a serial angiographic and intravascular ultrasound analysis from the Optimal Atherectomy Restenosis Study.

OBJECTIVES: The intravascular ultrasound (IVUS) substudy of OARS (Optimal Atherectomy Restenosis Study) was designed to assess the mechanisms of restenosis after directional coronary atherectomy (DCA). BACKGROUND: Recent serial IVUS studies have indicated that late lumen loss after interventional procedures was determined primarily by the direction and magnitude of arterial remodeling, not by cellular proliferation. METHODS: Complete quantitative coronary angiography (QCA) and IVUS were obtained in 104 patients before and after intervention and during follow-up. All studies were performed after administration of 200 microg of intracoronary nitroglycerin. Angiographic measurements included minimum lumen diameter (MLD), interpolated reference diameter and diameter stenosis (DS). Intravascular ultrasound measurements included lesion and reference external elastic membrane (EEM), lumen and plaque+media cross-sectional area (CSA). The axial location of the lesion site was at the smallest follow-up lumen CSA; the reference segment was the most normal-looking cross section within 10 mm proximal to the lesion but distal to any major side branch. Results are reported as mean +/- one standard deviation. RESULTS: The QCA reference decreased from 3.51 +/- 0.46 mm to 3.22 +/- 0.44 mm; the MLD decreased from 3.22 +/- 0.47 mm to 2.03 +/- 0.72 mm; and the DS increased from 8 +/- 10% to 38 +/- 20%. On IVUS, the decrease in lumen CSA (from 8.8 +/- 2.5 mm2 to 5.5 +/- 4.0 mm2) was associated with a significant decrease in EEM (from 19.7 +/- 5.6 mm2 to 16.9 +/- 6.2 mm2); there was no significant increase in P+M (from 10.9 +/- 4.2 mm2 to 11.3 +/- 3.9 mm2). A change in lumen correlated with a change in EEM (r = 0.790, p < 0.0001), not with a change in P+M (r = 0.133, p = 0.2258). A decrease in reference EEM (from 19.1 +/- 7.7 mm2 to 17.6 +/- 8.0 mm2) also correlated with a decrease in lesion EEM (r = 0.665, p < 0.0001). Results in restenotic lesions were similar. CONCLUSION: Restenosis after optimal DCA is caused primarily by a decrease in EEM CSA that extends into contiguous reference segments.

The ventilatory threshold: quantitative analysis of reproducibility and relation to arterial lactate concentration in normal subjects and in patients with chronic congestive heart failure.

The present study evaluates optimal ventilatory criteria and exercise protocols for determining the ventilatory threshold, and assesses the day-to-day reproducibility of the ventilatory threshold and its relation to peak oxygen uptake VO2 and blood lactate concentration in normal subjects and patients with stable chronic congestive heart failure (CHF). Eighteen normal subjects and 18 patients underwent rapid (1-minute stage) and gradual (3-minute stage) bicycle exercise tests on consecutive days. The ventilatory threshold was determined from computer-generated printouts of expired gas variables measured breath by breath. Interobserver variability of ventilatory threshold was small in both normal (0.66 +/- 0.85 ml/min/kg) and CHF patients (0.50 +/- 0.46 ml/min/kg). Variability in the normal subjects was lower for the rapid exercise protocol (0.66 +/- 0.85 ml/min/kg) than the gradual protocol (1.72 +/- 1.63 ml/min/kg) (p less than 0.05), but both protocols produced similar results in the CHF group. Day-to-day reproducibility of ventilatory threshold was high (r = 0.91, standard error of the estimate 1.74 ml/min/kg) and was similar to that of peak VO2 (r = 0.95, standard error of the estimate 3.31 ml/min/kg). The use of co-plotted ventilatory equivalents for oxygen and carbon dioxide yielded ventilatory threshold values comparable to values obtained by using multiple parameters (r = 0.94, p less than 0.0001). Although the ventilatory threshold did not predict a precise lactate level for individual subjects, the lactate increment at the ventilatory threshold occurred within a narrow range in both normal subjects and patients with CHF; the increase was 7.5 +/- 4.5 mg/dl and 7.7 +/- 4.1 mg/dl, respectively, indicating a relation to initial increases in blood lactate.

Acute dose range study of milrinone in congestive heart failure.

To determine the magnitude and time course of the optimal acute hemodynamic response to oral milrinone, an ascending dose range study was performed in 34 patients with severe chronic congestive heart failure (2.5 to 10 mg, n = 21; 7.5 to 15 mg, n = 13). With the 7.5- and 10-mg doses in both groups, cardiac index increased 26%, pulmonary capillary wedge pressure decreased 25% and systemic vascular resistance decreased 20%, with peak effect at 90 minutes. The hemodynamic improvement with 10 mg was sufficient to normalize cardiac index in 29% of patients. There was a clear dose-response relation, with the largest increases of cardiac index seen with the 15-mg dose (1.67 +/- 0.10 to 2.31 +/- 0.11; p less than 0.005). This dose-response relation was confirmed by the correlation of drug levels and change in cardiac index. However, some patients had significant hypotension and tachycardia with the 15-mg dose. Thus, although 10 mg appears to be optimal for most patients, the dose of milrinone should be individualized for all patients.

Safety and efficacy of intravenous diltiazem in atrial fibrillation or atrial flutter.

This study examines the efficacy of various doses of intravenous diltiazem to control the ventricular response during atrial fibrillation or atrial flutter. Control of the ventricular response of patients with atrial fibrillation and a rapid ventricular response can provide patients with relief of symptoms and improve hemodynamics. Eighty-four consecutive patients with atrial fibrillation or atrial flutter, or both, received an intravenous bolus dose of diltiazem followed by a continuous infusion of diltiazem at 5, 10, and 15 mg/hour. The mean ventricular response and blood pressure were monitored. Overall, 94% of patients (79 of 84) responded to the bolus dose with a > 20% reduction in heart rate from baseline, a conversion to sinus rhythm, or a heart rate < 100 beats/min. Seventy-eight patients received the continuous infusion. After 10 hours of infusion, 47% of patients (confidence interval [CI]: 36%, 59%) had maintained response with the 5 mg/hour infusion, 68% (CI: 57%, 79%) maintained response after the infusion was titrated to 10 mg/hour, and 76% (CI: 66%, 85%) after titration from the 5 and 10 mg/hour infusion to the 15 mg/hour dose. For the 3 diltiazem infusions studied, mean (+/- SD) heart rate was reduced from a baseline value of 144 +/- 14 beats/min to 98 +/- 19, 107 +/- 25, 107 +/- 22, 101 +/- 22, 91 +/- 17, and 88 +/- 18 beats/min at infusion times 0, 1, 2, 4, 8, and 10 hours, respectively. By the end of the infusion, 18% of patients (14 of 78) had conversion to sinus rhythm.(ABSTRACT TRUNCATED AT 250 WORDS)

Survival in severe left ventricular failure treated with the new nonglycosidic, nonsympathomimetic oral inotropic agents.

Survival in severe left ventricular failure is poor but has not been widely assessed since the introduction of several new nonglycosidic, nonsympathomimetic oral inotropic agents for long-term therapy. We examined retrospectively the survival of 82 patients with severe left heart failure during long-term treatment with oral milrinone (17 patients), posicor (12 patients), enoximone (47 patients), and piroximone (6 patients). Sixty-five patients were in New York Heart Association (NYHA) functional class 4, 15 patients were in class 3, and two patients were in class 2. There were 57 patients with ischemic and 25 patients were in class 2. There were 57 patients with ischemic and 25 patients with nonischemic etiology of left heart failure. Most patients were referred for inotropic therapy after failing to respond to conventional agents, including vasodilators. However, in almost all patients, marked hemodynamic and clinical improvement occurred initially. Overall survival was 36 percent at six months, the majority of deaths occurring during the first three months. Survival in relation to etiology of heart failure showed a trend toward increased mortality in patients associated with ischemic heart disease vs non-ischemic dilated cardiomyopathy. Sudden death mortality was also higher in the ischemic group (28 percent at six months vs 5 percent at six months; p less than 0.05). There was a trend toward reduced sudden death mortality in patients on antiarrhythmic agents during inotropic therapy (p = 0.06). We conclude that overall survival in symptomatic patients with severe left ventricular failure remains very low during long-term therapy with several new oral inotropic agents. Sudden death appears higher in patients with an ischemic etiology during therapy with these agents.

The safety and efficacy of the StarClose Vascular Closure System: the ultrasound substudy of the CLIP study.

BACKGROUND: The StarClose Vascular Closure System (Abbott Vascular, Redwood City, CA) features a nitinol clip that is designed to achieve closure of the femoral arteriotomy access site. The CLIP Study was performed to assess the safety and efficacy of StarClose when compared with standard manual compression following 5-6 French diagnostic or interventional percutaneous procedures. A substudy of this trial was designed to assess the utility of duplex ultrasonography to assess patency of the femoral artery and to determine access site complications (pseudoaneurysm, arteriovenous fistula, hematoma, deep vein thrombosis) in a multicenter prospective trial. This is the report of the duplex ultrasound (DUS) substudy of the CLIP trial. METHODS: A total of 17 U.S. sites enrolled 596 subjects with 483 subjects randomized at a 2:1 ratio to receive StarClose or manual compression of the arteriotomy after a percutaneous procedure. The study included roll-in (n = 113), diagnostic (n = 208), and interventional (n = 275) arms with a primary safety endpoint of major vascular complications through 30 days and a primary efficacy endpoint of postprocedure time to hemostasis. A substudy of the CLIP interventional arm evaluated DUS images of the closure site at five study sites, targeting 100 subjects at day 30 following hemostasis. The DUS protocol was devised and implemented by an independent vascular ultrasound core laboratory with extensive experience in vascular device trials. DUS inguinal region from 6 cm proximal to 6 cm distal to the arteriotomy puncture was performed. A qualitative examination was performed to determine the presence of iatrogenic vascular injuries: hematoma, pseudoaneurysm (PSA), arteriovenous fistula (AVF), and arterial/venous thrombosis or stenosis using 2-dimensional gray scale, color, and focused Doppler images. RESULTS: DUS of 96 subjects randomized to StarClose (n = 71) and compression (n = 25) were performed and evaluated. There was no evidence of hematoma, PSA, or AVF observed in the StarClose group. No StarClose subjects in the substudy had a PSA or AVF. All patients in the substudy demonstrated patency of the access site artery and vein without thrombosis or stenosis. Finally, in the entire study cohort, no clinically-driven DUS studies demonstrated iatrogenic vascular injury or vessel thrombosis in the StarClose treated patients. CONCLUSION: DUS, a safe and reliable method for determining the safety and efficacy of access site closure devices, is a reliable, safe, inexpensive and accurate method of assessing vascular access site complications in multicenter trials. In this substudy of the CLIP study, DUS found no statistical difference in access site complications between the StarClose and manual compression groups. Both groups maintained vessel patency without stenosis, thrombosis, hematoma, pseudoaneurysm, or AV fistula.

The StarClose Vascular Closure System: interventional results from the CLIP study.

BACKGROUND: The StarClose Vascular Closure System is a femoral access site closure technology that uses a flexible nitinol clip to complete a circumferential, extravascular arteriotomy close. The Clip CLosure In Percutaneous Procedures study was initiated to study the safety and efficacy of the StarClose device in subjects undergoing diagnostic and interventional catheterization procedures. METHODS: A total of 17 U.S. sites enrolled 596 subjects, with 483 subjects randomized at a 2:1 ratio to receive StarClose or standard compression of the arteriotomy after the percutaneous procedure. The study included roll-in (n = 113), diagnostic (n = 208), and interventional (n = 275) arms with a primary safety endpoint of major vascular complications through 30 days and a primary efficacy endpoint of postprocedure time to hemostasis. RESULTS: The results of the diagnostic StarClose cohort have been reported separately. Results for the interventional arm revealed major vascular complications occurring in 1.1% of StarClose subjects (2/184) and 1.1% in manual compression subjects (1/91; P = 1.00). No infections were seen in either cohort. Minor complications in the StarClose interventional group occurred at a rate of 4.3% (8/184) and with compression at 9.9% (9/91; P = 0.107). Pseudoaneurysm or arteriovenous fistula was not seen with StarClose. With StarClose, procedural success was 100% (136/136) for the diagnostic group and 98.9% (181/183) in the interventional group. Device success for the treatment group was 86.8%. In the interventional cohort, 87.3% (158/181) of StarClose subjects reported a pain scale of 0-3 compared with 93.3% (84/90) in the compression group, which was not statistically different. CONCLUSIONS: The clinical results of this study demonstrate that the StarClose Vascular Closure System is noninferior to manual compression with respect to the primary safety endpoint of major vascular events in subjects who undergo percutaneous interventional procedures. StarClose significantly reduced time to hemostasis, ambulation, and dischargeability when compared with compression.

Directional coronary atherectomy: optimal atherectomy trials and new combined strategies with coronary stents.

Directional coronary atherectomy (DCA) has evolved from its early use as a tool for minimal plaque debulking to its current use of more aggressive lumen enlargement. The trend toward improved lumen results and reduced restenosis following DCA compared to percutaneous transluminal coronary angioplasty (PTCA) in the Coronary Angioplasty Versus Excisional Atherectomy Trial (CAVEAT) was confirmed as a significant improvement in the subsequent Balloon versus Optimal Atherectomy Trial (BOAT). BOAT showed that acute lumen results and late angiographic restenosis could be significantly improved by DCA over PTCA, without any increase in procedural complications or late cardiac events. The role of DCA in conjunction with coronary stents is currently being defined as studies suggest that residual plaque burden after stenting is predictive of late restenosis. The Atherectomy before Multilink Stent Improves Lumen Gain and Clinical Outcomes Study (AMIGO) will help determine whether plaque debulking prior to stenting can reduce restenosis.

Lesion-specific technique considerations in directional coronary atherectomy.

Directional coronary atherectomy (DCA) has expanded over the past several years to include treatment of a wide variety of complex coronary lesions in difficult vessel locations. Ulcerated, eccentric, and hazy lesions; ostial, mid, distal, and bifurcation lesions; saphenous vein graft lesions; tandem and long lesions; and "rescue" of failed angioplasty lesions are all potentially well-suited for DCA. This paper describes a lesion-specific strategy for DCA and outlines equipment selection and techniques helpful for performing DCA in a broad range of cases.

Preservation of regional myocardial function during coronary angioplasty with an autoperfusion balloon catheter: a case report.

Echocardiographic assessment of regional myocardial function was performed during standard balloon coronary angioplasty followed by autoperfusion balloon angioplasty of a proximal left anterior descending artery stenosis. Septal and apical akinesis occurred within 60 seconds of standard balloon inflation, but regional function was well preserved during prolonged autoperfusion balloon inflation.

Necrotizing soft-tissue infection from rectal abscess.

Rectal abscess may result in necrotizing soft-tissue infection including fasciitis, myositis, and extraperitoneal dissection of pus without muscle necrosis. The presentation and therapy of ten patients treated over the past six years are reviewed. Early recognition of rapidly spreading infection was imperative. The mortality rate of 40 per cent correlated with the degree of sepsis present at admission. The high mortality attendant with the complications of rectal abscess emphasizes the need for aggressive therapy, including frequent examinations under anesthesia, wide debridement, systemic triple antibiotic therapy, diverting colostomy, aggressive wound care, and hyperalimentation.

Balloon angioplasty of the internal mammary artery trunk for early postoperative ischemia: a case report.

In this case report kinking of the internal mammary artery graft with possible superimposed spasm is described. Angiographic diagnosis was made 72 hrs following coronary artery bypass surgery and the lesion was successfully dilated with balloon angioplasty.

Hemorrhoidal ligation. A review of efficacy.

Two hundred forty-one patients undergoing hemorrhoidal rubber band ligation over a five-year period were reviewed to focus on complications. Three patients (1.2 percent) were hospitalized. Two, on oral anticoagulants, recovered from bleeding complications. One patient developed a band-related abscess that resolved with drainage. Twenty patients (8.3 percent) reported pain associated with the procedure. Three patients went on to subsequent surgical hemorrhoidectomy. There were no deaths in the series. This report agrees with previously published series highlighting the efficacy and cost containment of hemorrhoidal ligation. Continued reliance on this approach to hemorrhoidal disease is justified.

Myocardial protection during coronary angioplasty with an autoperfusion balloon catheter in humans.

An autoperfusion balloon catheter was developed to allow passive myocardial perfusion during inflation through a central lumen and multiple side holes in the shaft proximal and distal to the balloon. We report its safety and efficacy in 11 patients undergoing elective angioplasty to a single coronary lesion. Each lesion was dilated three times with the autoperfusion inflation bracketed between two inflations by standard angioplasty catheters. Chest pain score, 12-lead electrocardiogram, heart rate, and mean aortic pressure were recorded before each inflation and at 1-minute intervals after inflation. Inflation duration during autoperfusion angioplasty (513 +/- 303 seconds) was longer than for the pre- (107 +/- 55 seconds, p = 0.0004) and post- (139 +/- 71 seconds, p = 0.0006) standard dilatations. The maximum ST-segment elevation and depression in any lead during autoperfusion angioplasty (0.3 +/- 0.5 and 0.6 +/- 0.8 mm) was significantly less than for the pre- (2.4 +/- 1.7 mm, p = 0.002 and 2.2 +/- 1.3 mm, p = 0.0004) or post- (1.9 +/- 1.3 mm, p = 0.002 and 1.6 +/- 1.3 mm, p = 0.018) standard dilatations at the same point in time. Maximal chest pain score during autoperfusion (3.2 +/- 3.5) was lower than for the pre- (6.1 +/- 2.1, p = 0.003) but not the post- (5.2 +/- 3.1, p = 0.07) standard angioplasty. All 11 patients underwent successful, uncomplicated procedures. We conclude that this autoperfusion catheter significantly reduces ischemic symptoms and signs during coronary angioplasty, allowing prolonged periods of balloon inflation.