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Endotracheal intubation carries the risk of discomfort, decompensation, oral trauma, and endotracheal tube malposition. Treatment with premedications reduces complications, increases overall intubation safety, improves pain control, and improves first-pass success. However, time is frequently a barrier to administration. We aimed to decrease the decision-to-intubation time interval from a baseline of 40 minutes to less than 35 minutes over 6 months., Methods: We used the Model for Improvement with multiple plan-do-study-act cycles to reduce the time from decision to successful intubation in nonemergent neonatal intubations. Key drivers were timely administration of medications, availability of skilled personnel and equipment, and efficient use of time., Results: During this project, time from the decision to successful intubation decreased from a historical mean of 40 minutes to a new baseline of 27 minutes. This change represents a 33% decrease, with 80% of intubations occurring within 35 minutes. During this time, success rates remained stable, and medication errors and side effects did not increase., Conclusions: Standard processes to prepare and administer premedications decreased the time from decision to intubation without significant adverse effects, allowing the benefit of premedication administration in a safe and timely manner in nonemergent neonatal intubations., (Copyright © 2019 the Author(s). Published by Wolters Kluwer Health, Inc.)

Objectives: Cardiac troponins are highly sensitive and specific markers of myocardial cell injury. We wished to determine the clinical relevance of raised troponins in the absence of significant angiographic coronary artery disease., Design and Methods: We assessed patients admitted to our hospital over the past 3 years with troponin-positive chest pain and no angiographically significant coronary disease., Results: The study included 67 patients, all of whom had symptoms of "chest pain" and elevated (>0.2 microg/L) troponin I on admission. Thirty-four (51%) patients had alternative causes for myocyte injury other than coronary ischaemia. In the remaining 33 (49%) patients we could find no other associated features or diagnoses. Follow up was obtained in 29 (88%) of these 33 patients (mean follow up 58+/-13 weeks, range 17-156 weeks). During the follow up period, three (4.5%) patients were readmitted with further ischaemic events., Conclusions: Myocardial damage can occur in the absence of significant angiographic coronary disease and other causes of raised troponins should be considered according to the clinical presentation. Troponin-positive cases with angiographically "normal" coronary arteries can re-present with future cardiac events and should still be considered for aggressive risk management.

Background: Direct coronary stenting has been shown to be safe and feasible, with a demonstrable reduction in cost, procedural time and radiation exposure. Direct stenting may limit distal embolization of atherosclerotic plaque and consequently reduce myocardial cell injury following percutaneous coronary intervention, which may have important prognostic implications., Methods and Results: We assessed cardiac troponin I (cTnI) release in the 24 hours following direct coronary stenting (DS) as compared to stenting with balloon predilatation (PD) in a total of 311 patients and 440 vessels/lesions (vessel to lesion ratio = 1:1) (DS: n = 107 patients and 149 vessels/lesions; PD: n = 204 patients and 291 vessels/lesions). The 2 groups were well matched except for a greater proportion of diabetic patients in the PD group (21%) compared to the DS group (11%) (p < 0.05). There were no significant differences in the distribution of target lesion site or angiographic complexity between the 2 groups. Primary angiographic success was achieved in 97% of vessels in the DS group and 98% of vessels in the PD group (p = NS). DS failed in 7/114 patients (6%) deemed suitable for DS by the operator, but all stents were subsequently successfully deployed following balloon predilatation. Abciximab (ReoPro , Eli Lilly Company, Indianapolis, Indiana) was used in 11 patients (10%) in the DS group and 24 patients (12%) in the PD group ( p = 0.68). The post-procedural median (IQR) peak cTnI concentrations were 0.2 0.1 g/L in the DS group and 0.5 0.3 g/L in the PD group (p = 0.02). Post-procedural cTnI concentrations were > 0.2 g/L in 11 patients (10%) in the DS group and in 53 patients (26%) in the PD group (X2 = 58.6; p < 0.0001). The rate of major adverse cardiac events at 6 18 month follow-up was 8% in the DS group and 15% in the PD group (X2 = 38.5; p = 0.02)., Conclusion: Direct stenting without balloon predilatation is associated with lower post-procedural cTnI concentrations and lower incidence of major adverse events compared to traditional stenting with predilatation.

Objective: To examine the clinical outcome of percutaneous coronary intervention where the procedure was complicated by vessel perforation., Setting: Tertiary referral centre., Methods: The procedural records of 6245 patients undergoing coronary intervention were reviewed. In 52 patients (0.8%) the procedure was complicated by vessel perforation, ranging from wire exit to free flow of contrast into the pericardial space. The majority of lesions treated were complex (37% type B, 59% type C) and 9 of 52 (17%) were chronic occlusions. Ten patients (19%) received abciximab. Four underwent rotational atherectomy (8%)., Results: In 28 of 52 patients (54%) the perforation was benign and managed conservatively without the development of haemodynamically significant sequelae. In 24 of 52 (46%) a significant pericardial effusion ensued requiring drainage. Of these 24 procedures 6 had involved the treatment of a chronic occlusion (25%). Eight of the 24 patients were referred for emergency bypass surgery (33%), 3 of whom died. Of the remaining 16 not referred for surgery, 3 died. Of the 10 procedures complicated by vessel perforation where abciximab had been administered, 9 (90%) led to pericardial tamponade. Latterly 2 vessel perforations were successfully treated by the deployment of a covered stent., Conclusions: Coronary artery perforation with sequelae during intervention is rare--26 of 6245 (0.4%). This complication was seen in the treatment of chronic occlusions, which are therefore not risk-free procedures. The development of pericardial tamponade carries a high mortality. While prompt surgical intervention may be life saving, expertise in the use of covered stents may provide a valuable rescue option for this serious complication. Caution should be exercised where coronary perforation occurs and abciximab has been used.

The large volumes of wastes generated by industrialised society has led to efforts to find practical uses for these wastes, whilst also offsetting the consumption of natural resources. This paper describes the use of an innovative rotary kiln to produce synthetic aggregates from a variety of waste streams. The main waste used was a quarry fines which was blended with either paper sludge, clay, or a dredged harbour sediment. The different combinations were extruded and fired in the kiln to produce a material suitable for natural aggregate replacement. Two of the synthetic aggregates produced were tested by incorporation in to concrete as coarse aggregate replacement. The concrete 28-day compressive strengths achieved were above 40 N mm(-2) and compared favourably with control concretes made with natural aggregates and a commercially available lightweight aggregate (Lytag). Leaching tests have also been carried out to assess the potential environmental impact of utilisation. Although not finalised, these tests have also given favourable results.

The high restenosis rates in long stents may be related to suboptimal stent deployment. In an attempt to understand the potential components associated with restenosis in long stents, this study compares angiographic and intravascular ultrasound (IVUS) data from the MUSIC and RENEWAL studies where IVUS was used to optimize stent deployment in short (< 15 mm) and long (> 20 mm) coronary lesions, respectively. The RENEWAL study, a randomized trial, compared the NIR stent and Wallstent in long (> 20 mm) coronary lesions and used on-line visual IVUS criteria to optimize stent expansion. Detailed analysis of IVUS data was performed off line. Angiographic and IVUS data from this study was compared to that from the MUSIC study. Initial stent deployment was deemed optimal by the operator after visual angiographic and IVUS assessment in 50 of 70 lesions. In the remaining 20 lesions further balloon inflations were required to optimize stent apposition that led to an average gain in minimal in-stent luminal area (MISA) of 15.9% (P < 0.01). Off-line IVUS data analysis showed that the number reaching "MUSIC criteria" for optimal stent deployment preredilatation was 8 (11.4%) of 70 and 14 (20%) of 70 postredilatation. The ratio of MISA/MRAprox (mean proximal reference area) was 0.69 in RENEWAL. At 6-month follow-up, the angiographic restenosis rate in RENEWAL was 36% and target lesion revascularization (TLR) rate was 7.8%, compared with MUSIC's 9.7% and 4.5%, respectively. In conclusion, angiographic assessment of stent deployment in long lesions is limited. On-line visual IVUS with further balloon inflations to improve stent apposition led to a significant gain in MISA, but the MISA/MRAprox ratio remained suboptimal. Therefore, suboptimal stent deployment due to constraint by lesion resistance may be an important mechanism underlying the high restenosis rates in long stents.

Background: A 91-year-old man presented with a 6-month history of exertional angina. As he was already on maximally tolerated medical therapy, we decided to perform coronary angiography, which revealed severe stenosis of the distal main stem coronary artery,, Outcome: The lesion was crossed with an intra-coronary wire, and a stent placed to cover the distal main stem lesion, without prior balloon dilatation. The result was satisfactory and he remains symptom-free at 6-month follow-up., Conclusion: Treatment of left main stem lesions with percutaneous intervention may be an acceptable alternative to surgery in high-risk elderly patients. Since percutaneous coronary angioplasty can be performed on very elderly patients with a high degree of success, the decision to investigate and treat should not be based solely on biological age.

Background: The role of coronary stents in reducing the incidence of acute complications and late restenosis after angioplasty has been established in randomized studies focusing on simple, short coronary lesions. The development of long coronary stents has provided a safe and predictable means of treating long coronary lesions, but this carries with it a higher risk of restenosis. By comparing the outcome of treating long lesions with two different stent types, we aimed to assess the influence of stent design rather than the nature of long lesions per se on the relatively high restenosis rates in this subgroup., Methods: This study was designed to assess procedural complications and 6-month restenosis rates in a randomized trial comparing a slotted tube stent with a self-expanding stent for the treatment of long coronary lesions. Randomization of vessels to either stent occurred after successful balloon angioplasty. Intravascular ultrasound (IVUS) was used to assess and optimize stent deployment. The patients were restudied angiographically and by IVUS at 6 months., Results: A total of 82 patients (85 vessels) were recruited (slotted tube stent, n = 44 vessels; self-expanding stent, n = 41 vessels). Successful deployment occurred in 41 (100%) of 41 of the self-expanding stent group and 41 (93%) of 44 of the slotted tube stent group. There was no difference in lesion length between the two groups (slotted tube stent, 26.6 +/- 6.9 [SD] mm; self-expanding stent, 28.7 +/- 9.8 [SD] mm; P = .2), but the mean length of the self-expanding stent was greater than that of the slotted tube stent (41.6 +/- 18.8 [SD] mm vs 35.4 +/- 16.2 [SD] mm, respectively; P < .05). There was no significant difference in the rate of major events between the two groups at 6-month follow-up. The angiographic restenosis rate at follow-up was less in the slotted tube stent group, but this did not reach statistical significance (26% vs 46%, respectively; P = .1) and the target lesion revascularization rate was similar for both groups (7.9% vs 7.7%, respectively; P = .8). IVUS assessment of plaque/stent ratios suggested a greater plaque burden in the self-expanding stent compared with the slotted tube stent at follow-up (0.42 +/- 1.2 [SD] vs 0.3 +/- 0.08 [SD]), but this was not statistically significant (P = .1)., Conclusions: Long stents can be safely and successfully deployed in long segment coronary disease, with an acceptable 6-month target lesion revascularization rate. Our results showed a trend toward lower angiographic restenosis and a lesser in-stent plaque burden at follow-up in the slotted tube stent compared with the self-expanding stent. This suggests that stent design may influence the restenotic process in long coronary lesions.

Objective: To create a risk model for predicting major adverse complicating events of percutaneous transluminal coronary angioplasty (PTCA), and to test the accuracy of the model on a prospective cohort of patients, Setting: Tertiary cardiac centre, Methods: Available software can predict probabilities of events using Bayes's theorem. To establish the accuracy of these predictive tools, a Bayes table was created to evaluate major adverse complicating events (MACE)-death, emergency coronary artery bypass grafting (CABG), or Q wave infarct occurring during the in-patient episode-on the first 1500 patients in the department PTCA database (development group); the predictive value of this model was then tested with the subsequent 1000 patients (evaluation group). The following probabilities were assessed to determine their association with MACE: age, sex, left ventricular function, American Heart Association lesion morphology classification, cardiogenic shock, previous CABG, diabetes, hypertension, multivessel PTCA., Main Outcome Measures: To establish the discriminatory ability of the predictive index, calibration plots and receiver operating characteristic (ROC) curves were obtained to compare the development and evaluation groups., Results: The ROC curve plotted to determine the discriminatory value of the Bayesian table created from the development group (n = 1500) in predicting MACE in the evaluation group (n = 1000) showed a moderately predictive area under the curve of 0.76 (SEM 0.07). This predictive accuracy was confirmed with separately constructed calibration plots., Conclusions: Accurate predictions of MACE can be identified in populations undergoing percutaneous intervention. The database used allows operators to obtain consent from patients appropriately from their own experience rather than from other published data. If a national PTCA database existed along similar lines, individual operators and interventional centres could compare themselves with nationally available data.

This study assessed clinical and angiographic restenosis following the deployment of the long coronary Wallstent. Between May 1995 and June 1997, 182 Wallstents were deployed in 162 vessels in this unit. Forty-eight percent had an unstable coronary syndrome and 94% had AHA grade B or C lesions. The mean lesion length was 37 +/- 20 mm and the mean stent length was 48 +/- 20 mm. The procedural success rate was 99% and the primary success rate was 93%. Six in-patients suffered subacute stent thrombosis, the majority being in the era of anticoagulation rather than antiplatelet regimes. Seventy-three percent remained free of major adverse clinical events in the follow-up period, but 41% had angiographic restenosis. The Wallstent can be deployed in complex lesions with a high primary success rate and an acceptably low restenosis rate. The optimal management of in-stent restenosis remains to be defined., (Copyright 1999 Wiley-Liss, Inc.)

BACKGROUND: Currently little data exists on the use of single intracoronary stents for the treatment of long coronary artery lesions. The aim of this study was to evaluate the 18 mm Palmaz-Schatz stent (PS no. 204C) for the primary treatment of native coronary lesions between 15 mm and 18 mm in length. METHODS: A consecutive group of 17 patients were included in this study over a 3 month period. Each patient selected was felt suitable for elective treatment with an intracoronary stent and had a coronary artery lesion of >15 mm in length. Coronary arteriograms recorded just before PTCA, after full stent deployment and electively at 4 months after stent deployment were analyzed using semi-quantitative coronary angiography. RESULTS: Mean lesion length treated was 16.9 mm. The primary success rate for stent delivery was 16 out of 17 lesions. One patient required immediate coronary artery bypass surgery for extensive dissection of the right coronary artery. There were no out of hospital complications and no patient suffered acute or subacute stent thrombosis. All patients had an improvement in their Canadian Cardiovascular Angina Class: Three patients (21%) had asymptomatic restenosis (stenosis 50%) at follow-up angiography. CONCLUSION: This study shows the 18mm Palmaz-Schatz stent is relatively successful for the elective treatment of long coronary artery stenoses. Although the mean lesion length of 16.9 mm in this study is significantly greater than that of the BENESTENT and STRESS studies, the 21% restenosis rate is comparable.

Background: The value of angioplasty in occluded coronary arteries is limited by a restenosis/reocclusion rate of 50-70%. In patients with subtotal occlusion, stent implantation has been shown to reduce clinical and angiographic restenosis. Retrospective observational studies have suggested that stenting could reduce restenosis in total occlusions. The value of sustained coronary patency on global and regional left ventricular function in this clinical setting has not been defined clearly., Objectives: To assess the medium term effect of elective intracoronary stent deployment after successful percutaneous transluminal coronary angioplasty (PTCA) of an occluded coronary artery., Methods: Sixty patients with a total coronary occlusion successfully treated by PTCA were randomised to receive an intracoronary stent or no stent. Patients underwent clinical and angiographic follow up at six months., Results: Thirty patients received a stent (group A) and 30 were treated by angioplasty alone (group B), all with initial success. One patient in group B required repeat angioplasty with stenting at 24 hours and one patient died after 10 days. Angiographic follow up was available for 57 patients. This showed a significantly reduced reocclusion rate in group A compared with group B (7% v 29%, p < 0.01) and a tendency to a reduced restenosis rate (22% v 40%, p = 0.105) in patients with no reocclusion. Left ventricular function, both global and regional, improved in group A. Only the regional left ventricular function in the area supplied by the target coronary artery improved in group B. Recurrence of symptoms and clinical events such as repeat angioplasty, coronary artery bypass grafting, death or myocardial infarction tended to be reduced in group A (4 (13%) v 9 (30%))., Conclusions: Intracoronary stent insertion is effective in reducing the rate of reocclusion and shows a trend towards reduced restenosis after opening of a total coronary occlusion by balloon angioplasty. Sustained patency of the target coronary artery is associated with improvement in global and regional left ventricular function.

Patients with chronic renal failure undergoing renal transplantation have a high prevalence of cardiovascular disease. Invasive investigation may identify those at risk of cardiac death during or after renal transplantation, but which patients should undergo cardiac catheterization is currently not clear. In 95 patients awaiting renal transplantation we assessed the ability of echocardiography and exercise electrocardiography to identify patients at risk of cardiac death. Echocardiography identified impaired left ventricular (LV) systolic function in 20%, severe in 8%. Of the patients with severe LV dysfunction, 25% died before transplantation. Of those undergoing exercise electrocardiography, 44% did not achieve 85% of maximum predicted heart rate. No coronary artery disease requiring intervention was identified by exercise testing. These findings indicate that echocardiography, but not exercise electrocardiography, should be part of the assessment for renal transplantation.

In order to provide atrioventricular synchrony, VDD pacing systems require reliable atrial sensing. Variations in atrial signals with exercise and daily activities may lead to undersensing, with loss of physiological pacing. The aim of this study was to determine, for a single lead VDD pacing system, the maximal variation in atrial signals in order to facilitate optimal programming of atrial sensitivity. Fifteen patients underwent implantation of a Vitatron Saphir VDD pacemaker with a Vitatron Brilliant electrode. At a mean (+/-SD) follow-up of 67.3 +/- 38.8 days, resting P wave amplitude was compared with the P wave amplitude histogram obtained from the pacemaker, which recorded atrial signals over the preceding 30 days. Resting P wave amplitude was also compared with P wave amplitudes during variations in posture, respiration, and during exercise. P wave amplitude showed great variation with changes in posture and respiration, but there was no consistent increase or reduction. During exercise, the mean P wave amplitude fell by 36.6% +/- 31.3% compared with the resting value (P < 0.05). During daily activities, 22.6% of P wave amplitudes recorded on the P wave histogram were < 0.5 mV. The smallest P wave amplitudes were detected by the P wave histogram in 11 (79%) of 14 patients. These data suggest that atrial sensitivity may need to be programmed higher than that indicated by single readings or exercise. The P wave amplitude histogram is the most reliable indicator of the smallest atrial signal and should be used to optimize atrial sensitivity settings.

Background: Traditionally, cardiac catheterization in patients with severe aorto-iliac disease has been performed using a brachial arteriotomy. This approach is associated with significant vascular and neuronal complications and requires considerable training to achieve an adequate level of expertise. Improvement and miniaturization of catheter equipment now allows the radial artery to be used for coronary investigation and intervention. The lack of important structures close to the radial artery, a good collateral ulnar artery circulation and its superficial position suggests that these procedures should have a low complication rate. The purpose of this study was to assess the efficacy and safety of percutaneous transradial diagnostic and interventional coronary catheterization in patients with severe peripheral vascular disease., Patients and Methods: We undertook a non-randomized prospective analysis of 75 patients who had transradial artery diagnostic and interventional coronary catheterization in whom femoral angiography was impossible or relatively contraindicated (22 patients with severe claudication and absent femoral pulses, 24 patients with previous aorto-iliac surgery or intervention, 20 patients with a failed femoral approach, 9 patients with an aortic aneurysm). Three patients had an absent ulnar artery and were excluded., Results: Radial artery cannulation was successful in 73/75 (97%) cases. Seventy-one (95%) patients had a successful diagnostic study. There was a high incidence of 3 vessel disease (73%), and the majority of patients (64%) were referred for coronary bypass surgery. Twelve patients underwent successful follow-on intervention including the insertion of 9 intracoronary stents. Adequate haemostasis was achieved within 20 min after diagnostic angiography and 60 min after interventional procedures. One patient had a forearm haematoma with paraesthesia of the hand which settled with conservative treatment. At 4-6 weeks, all patients had normal hand sensation and function (100%) with a palpable pulse present in 59/62 (96%). All patients undergoing diagnostic angiography were discharged on the same day, and patients undergoing intervention were discharged the following day., Conclusions: Transradial coronary investigation and intervention can be performed with a high degree of success and a low complication rate with early mobilization and discharge in patients with severe peripheral vascular disease. We suggest that the percutaneous transradial technique should be considered as an alternative to the Sones' technique in these patients.

BACKGROUND: Percutaneous transluminal coronary angioplasty is associated with higher rates of acute complications and restenosis when performed in the clinical setting of unstable angina. Coronary stent insertion has been shown to reduce restenosis when performed electively. The effect of unstable angina on clinical outcome after stent deployment is currently unclear. OBJECTIVE: To compare the clinical outcome after coronary stents inserted in patients with unstable and stable angina. DESIGN: A retrospective analysis of all patients receiving Palmaz-Schatz stents electively or for sub-optimal angioplasty result in patients with stable and unstable angina. PATIENTS: One-hundred fifty-seven patients received 178 Palmaz-Schatz stents electively or for the treatment of sub-optimal result. Thrombolysis in Myocardial Infarction Study (TIMI) grade 3 flow was present in all patients at the time of stent delivery. Unstable angina was defined as pain at rest despite anti-anginal therapy (Braunwald class II, III). Eighty-three patients (mean age 58 years) with unstable angina received 95 stents and 74 patients (mean age 57 years) with stable angina received 83 stents. MAIN OUTCOME MEASURES: Subacute stent thrombosis (SAST), myocardial infarction (MI), need for repeat angiography, coronary bypass graft surgery (CABG) and death. RESULTS: The early complications (within 2 weeks) comparing the unstable and stable groups respectively were: No deaths, SAST 3/83 (3.6%) vs. 2/74 (2.7%), MI 2/83 (2.4%) vs. 2/74 (2.7%) and CABG 6/83 (7.2%) vs. 2/74 (2.7%). After 2 weeks no patient had a MI or CABG. Clinical follow-up was continued up to 6 months. Two patients in each group had repeat angiography for recurrent symptoms. One patient in the stable group died from non-cardiac causes. CONCLUSIONS: There appears to be no difference in the early or late clinical outcome of patients with unstable or stable angina treated with coronary stent insertion when TIMI flow is normal at the time of stent insertion.

Platelet activation and thrombus formation within the coronary artery are major factors in acute myocardial infarction (AMI) and unstable angina (UA), and continuing platelet activation is associated with an adverse prognosis. We assessed platelet activation by using flow cytometry to measure platelet surface expression of P-selectin and glycoprotein IIb/IIIa in 20 patients with AMI and 20 with UA, all of whom were treated with aspirin. Platelet studies were repeated after the infusion of a nitric oxide donor (glyceryl trinitrate or S-nitrosoglutathione) that produced a fall in mean arterial pressure of no more than 10 mm Hg. P-selectin was expressed on 2.5% (range, 1.4% to 6.3%) of platelets from AMI and 2.3% (range, 1.6% to 3.3%) from UA subjects compared with 1.0% (range, 0.6% to 1.9%) of platelets from 20 control volunteers without angina (P < .001). Glycoprotein IIb/IIIa expression was 101.6 +/- 2.7 arbitrary units of relative fluorescence in AMI and 100.2 +/- 3.3 in UA compared with 87.8 +/- 2.5 in control subjects (P < .01). In both AMI and UA, S-nitrosoglutathione reduced P-selectin (P < .001) and glycoprotein IIb/IIIa (P < .05) expression, as did glyceryl trinitrate (P < .02 and P < .01, respectively). In 3 of 20 patients receiving glyceryl trinitrate the lowest dose was not tolerated due to headache or hypotension. These findings show that platelet activation persists in AMI and UA despite aspirin treatment and that this can be inhibited by using glyceryl trinitrate or S-nitrosoglutathione. S-nitrosoglutathione is better tolerated at the doses required.

Background: Coronary stents may be used electively during percutaneous transluminal coronary angioplasty (PTCA) or as a "bail-out" device to treat abrupt or threatened vessel closure following PTCA., Objective: To compare the clinical outcome of elective and "bail-out" coronary stent insertion., Design: A retrospective analysis of all patients receiving coronary stents., Setting: Tertiary referral center performing over 400 PTCA procedures a year., Patients: Fifty-six patients (42 male), mean age 57 (range = 32 to 78) years received 67 Palmaz-Schatz coronary stents. Forty-nine stents were deployed as "bail-out" in 41 patients (abrupt vessel closure in 15 and threatened vessel closure in 26) and 18 stents were deployed electively in 15 patients., Main Outcome Measures: Myocardial infarction, repeat angiography, coronary artery bypass graft surgery and death., Results: Stents were successfully deployed in 56/62 (90.3%) patients. In-hospital events were significantly more common in the "bail-out" group compared to the elective group. The in-hospital events, comparing the "bail-out" group versus the elective group, were as follows: Death 2/41 (4.9%) vs 0/15 (0%), coronary artery bypass graft surgery (CABG) 8/41 (19.5%) vs 0/15 (0%), stent thrombosis 3/41 (7.3%) vs 0/15 (0%), and myocardial infarction 6/41 (14.6%) vs 1/15 (6.7%) respectively. After discharge no patient died or had CABG. One patient in the "bail-out" group had a myocardial infarct (late stent thrombosis). Two patients from each group had repeat angiography because of recurrent angina in the 6 month follow up period., Conclusion: "Bail-out" stenting has an increased incidence of in-hospital complications compared to elective procedures. If these short-term problems can be overcome however, the clinical events in the first 6 months after leaving hospital are low and similar to patients under-going elective procedures.

Platelet activation is associated with acute vessel occlusion and chronic restenosis after percutaneous transluminal coronary angioplasty (PTCA). Organic nitrates, which act by releasing the vasodilator and anti-platelet agent nitric oxide (NO), have a predominantly vasodilator action and cause hypotension at doses required to inhibit platelet activation. S-nitrosoglutathione (GSNO) is an NO donor with a preferential action on platelets. We investigated platelet activation in patients undergoing PTCA and the effect of GSNO. Blood was sampled from the coronary sinus to measure platelet surface expression of P-selectin and glycoprotein IIb/IIIa as indices of platelet activation. In 7 control patients, PTCA caused a rise in platelet surface expression of P-selectin and glycoprotein IIb/IIIa, which was maximal 5 minutes after PTCA, indicating increased platelet activation despite treatment with aspirin, glyceryl trinitrate, and heparin. 6 patients received an intracoronary infusion of GSNO, starting 10 min before PTCA. GSNO significantly inhibited the PTCA-induced increase in platelet surface expression of P-selectin and glycoprotein IIb/IIIa without altering blood pressure. These findings show that platelets are activated following PTCA and that GSNO can prevent this activation.

Coronary artery rupture is a rare complication of percutaneous transvenous coronary angioplasty (PTCA) usually requiring urgent cardiac surgery and often resulting in a poor outcome including death. We report, for the first time, the use of an intracoronary stent to control intrapericardial bleeding following the development of a coronary artery rupture during PTCA. Cardiac surgery was avoided and the patient was discharged well 1 week after the procedure.

Significant vessel tortuosity is a relative contraindication to the use of the Palmaz-Schatz coronary stent for fear of stent displacement during delivery. We describe a patient with unstable angina in whom conventional coronary angioplasty in an extremely tortuous right coronary artery resulted in an occlusive dissection. Emergency bypass surgery was avoided by the successful placement of a protected Palmaz-Schatz stent using a 5F Teleguide sheath.

The safety and tolerability of intermittent (16 hours on/8 hours off) nitrate patch therapy (0.2, 0.4 or 0.6 mg/hr: dose adjusted as required) was studied for a median duration of 356 days in 106 patients (mean age 60.9 +/- 8.6 years) with angina pectoris. Most patients (82%) were on existing beta-blocker and/or calcium antagonist therapy. Safety, tolerability and efficacy data were obtained by means of patient diary cards and regular clinic visits. Almost 90 treatment years revealed no significant or serious adverse events, and there were no changes in haematology or biochemistry associated with intermittent nitrate patch therapy. The most frequently reported side-effects were headache, skin reactions and dizziness (53%, 20% and 8% of patients respectively). Treatment resulted in a sustained reduction in the frequency and severity of angina attacks, reduced sublingual GTN consumption, an improvement in general wellbeing and a rise in the proportion of patients in whom angina was controlled.

Objective: To assess the efficacy and safety of a haemostatic bovine collagen plug (VasoSeal) in reducing patient immobilisation after cardiac catheterisation from a percutaneous femoral arterial approach., Design: A non-randomised, prospective analysis of a new biodegradable haemostatic agent on an intention to treat basis., Setting: The catheterisation suite of a regional cardiothoracic unit., Patients: A series of 63 patients having various diagnostic investigations and therapeutic interventions agreed to participate in this study., Interventions: Cardiac catheterisation was performed from a percutaneous femoral artery approach. Patients taking aspirin and those who required formal anticoagulation were not excluded. Patients were measured for the appropriate sized collagen delivery system at the beginning of the procedure. At the end of the procedure two bovine collagen plugs were applied to the surface of the femoral artery through the channel created by the application device., Main Outcome Measures: Incidence of successful delivery, insertion time, immediate outcome, inpatient complications, success of mobilisation of the patient at one and two hours after the procedure, and whether these variables relate to individual patient characteristics., Results: Successful placement of the device was achieved in 57 of 63 consecutive patients (90.5%). The mean (SD) insertion time was 86 (24) seconds. Six (9.5%) patients did not receive the haemostat because of femoral artery perforation by the tissue dilator (n = 3), inability to compress the femoral artery proximal to the site of delivery (n = 1), pre-existing haematoma (n = 1), or patient withdrawal from the study (n = 1). Uncomplicated mobilisation within two hours of investigation was possible in 54 of 57 (94.7%) patients receiving this device. A sizeable haematoma (> 5 x 5 cm) prevented early mobilisation in the remaining three patients. Mobilisation was uncomplicated in 32 of 34 (94.1%) patients mobilised at two hours and 22 of 23 (95.6%) at one hour (NS). One patient who was mobilised early without complication later developed evidence of claudication in the treated leg. Femoral arteriography showed a smooth intraluminal filling defect attached to the wall of the femoral artery at the puncture site. This obstruction, presumed to be a collagen plug, was treated successfully with angioplasty. Sheath size, arterial pressure, the use of aspirin, heparin or warfarin, and body mass index did not influence patient outcome. The pattern of complications did not relate to a learning curve experience., Conclusions: The bovine collagen haemostat is a relatively safe and effective device that allows far earlier patient mobilisation than conventional haemostasis after diagnostic and therapeutic interventions from a percutaneous femoral artery approach. These results have important implications for patients undergoing investigation in mobile x ray units or in hospital based day case units.

Transcoronary ablation of atrioventricular conduction by dehydrated alcohol was attempted in 14 patients with refractory atrial arrhythmias. Alcohol (0.5 or 1.0 ml) was delivered after selective catheterisation of the atrioventricular nodal artery in the 10 patients in whom the artery could be identified by cineangiography. The other four patients underwent electrical ablation when the nodal artery could not be catheterised. Temporary atrioventricular block induced by dilute contrast and cold saline (0.9%) confirmed that the catheter was in the correct position before the alcohol was delivered. In all 10 patients complete atrioventricular block developed after alcohol ablation. The block persisted in all four patients given 1.0 ml alcohol but not in four of the six given 0.5 ml. The mean (SD) creatine kinase (MB fraction) at four to six hours after ablation was 76.5 (49.5) IU after 1.0 ml and 75.5 (43.1) IU after 0.5 ml alcohol (normal less than 20 IU). The overall success rate of alcohol ablation in the whole group on an "intention to treat" basis was 43%. The procedure was a technical success in six of the 10 patients in whom the nodal artery was identified. Transcoronary alcohol ablation of atrioventricular conduction should be considered in patients in whom electrical techniques have been unsuccessful.

An unusual case of metastatic disease of the right ventricle is described in a 74-year-old woman who had presented with a malignant fibrous histiocytoma of the right thigh previously treated with surgery and radiotherapy. Two years later she presented with signs and symptoms of tricuspid regurgitation and right ventricular outflow tract obstruction. The diagnosis of right ventricular tumor was made by echocardiographic and angiographic studies and confirmed on postmortem examination.

The present single-blind, randomised, cross-over, placebo-controlled study was set up to compare the first-dose effects upon blood pressure (BP) and cerebral blood flow (CBF, measured by Xenon inhalation) of a single oral dose of atenolol 50 mg and enalapril 5 mg in ten hypertensive patients receiving a thiazide diuretic. It was found that a) the timing and degree of fall in BP after the first dose of atenolol and enalapril on a diuretic background were similar and generally not associated with symptoms or a fall in CBF, and b) dizziness, which is sometimes associated with the first-dose effect of ACE inhibitors in hypertensives on diuretics, can occasionally occur accompanied by a substantial fall (43%) in CBF in the absence of marked falls in systolic blood pressure. It is suggested that the latter event may be linked to a disturbance of cerebral autoregulation in part dependent on localised renin-angiotensin systems.

Sixty-five patients with angiographically documented coronary artery disease were investigated by thallium-201 (201Tl) scintigraphy to determine the role of the collateral circulation during dynamic exercise. Fifty-three patients had complete proximal occlusion of at least one major coronary artery. One patient had total occlusion of all three major coronary arteries. Sixty-four collateral channels were identified, graded, and compared with corresponding regions of the myocardial scintigram. Tracer uptake was also graded and classified as various degrees of protection from ischaemia. A significant correlation between good collaterals with complete protection and poor or absent collaterals with no protection was noted. Seventeen patients (20 occluded vessels) had total coronary occlusion without myocardial infarction. Collaterals conferred protection in 9/15 occlusions whereas no protection was seen in five occlusions without collaterals. There was no difference in the protective role of homocoronary and heterocoronary collateral vessels. Hypertrophy of the first septal left anterior descending perforator conferred significant protection from ischaemia in contrast to bridging collaterals and ghosting. During exercise the right coronary bed is preferentially protected from ischaemia, in contrast to the left anterior descending territory. This probably reflects the direction of a transmural flow gradient between left and right ventricles during exercise.

In a prospective double blind randomised study in 25 consecutive patients a conventional ionic contrast medium (Urografin 370) was compared with the new non-ionic medium iohexol 350 ( Omnipaque ) in left ventriculography and coronary arteriography. In left ventriculography there was a clear patient preference for iohexol by both a visual analogue scale and independent observer assessment. Iohexol also induced a smaller increase in heart rate or decrease in systolic blood pressure than Urografin. In coronary arteriography iohexol resulted in a smaller reduction in heart rate and systolic blood pressure, a smaller maximum increase in RR interval, less prolongation of the PQ and QT intervals and QRS duration, and a lower incidence of induced chest pain, ST segment depression, or T wave deflection.

Pacemaker recognition of pathological tachycardia relies on heart rate analysis. This can lead to misdiagnosis when sinus tachycardia exceeds the preset tachycardia response trigger rate. We have explored a method for automatic tachycardia diagnosis by analysis of bipolar endocardial electrogram morphology. Electrograms were recorded from 11 patients (pts) during sinus rhythm and during a total of 20 abnormal rhythms: retrograde atrial depolarization from ventricular pacing in six patients; atrioventricular reentry tachycardia in five patients with intermittent left bundle branch block in one of those; AV nodal reentry tachycardia in five patients and ventricular tachycardia in three patients. Posture and respiration were varied during all rhythms except ventricular tachycardia. The electrograms were then digitized and converted to a form in which the amplitudes were proportional to the rates of change of the original electrogram (equivalent to a first time derivative); the derived signal was then analyzed by a new gradient pattern detection (GPD) program. Analysis of the processed atrial signals by GPD resulted in automatic recognition of abnormal rhythms from sinus rhythm in all cases except for one patient's retrograde atrial depolarization. At the ventricular level, GPD successfully distinguished all abnormal rhythms from sinus rhythm including recognition of left bundle branch block and varying degrees of preexcitation. Respiratory and postural variation did not affect the recognition process. We conclude that electrogram GPD has successfully and automatically detected a variety of arrhythmias which can be treated by implantable pulse generators and may, therefore, be a useful adjunct to heart rate analysis in future generations of such antitachycardia pacemakers.

50 normotensive subjects (22 controls with no cardiac disease, 24 patients with coronary heart-disease, and 4 with early cardiomyopathy) were investigated with gated cardiac blood-pool scintigraphy before and during cold pressor stimulation. The controls had no change or a significant rise (p less than 0.005) in left ventricular ejection fraction and preserved normal myocardial-wall motion, whereas patients with coronary-artery disease or cardiomyopathy had a significant fall (p less than 0.001) in left ventricular ejection fraction and many developed abnormal regional wall motion despite the absence of angina pectoris. Cold pressor gated cardiac blood-pool studies were more sensitive than single-lead exercise electrocardiography (p = 0.03) in the detection of patients with severe coronary-artery disease without previous myocardial infarction.

Transvenous catheter ablation of the anomalous pathway was attempted in seven patients with drug-resistant repetitive long RP tachycardias. The patients were aged 5.5-65 years (median 20 years) and had received from four to seven antiarrhythmic agents without effect. Electrophysiological studies confirmed the anomalous substrate for tachycardia in five patients but in two patients an intranodal mechanism could not be excluded. Discharges were delivered to the coronary sinus ostium or low right atrium close to the ostium using conventional defibrillators (three patients) or a modified device (four patients). Transient AV block was seen after six attempts progressing to permanent block in one patient. In no patient could enduring block in the retrograde limb of tachycardia be achieved, and tachycardia recurred in all patients in whom anterograde conduction remained intact. The failure of selective ablation techniques in long RP tachycardia may reflect the diversity of substrate anatomy or particular properties (anatomical or functional) of the pathway compared with the usual types of anomalous pathway.

90 patients were enrolled into this preliminary multicentre study of the efficacy and safety of 30 units intravenous anisoylated plasminogen streptokinase activator complex (APSAC) compared with placebo in patients with acute myocardial infarction. 45 patients received APSAC and 45 placebo; the groups were similar for age, weight and site of infarction. There were significantly more women treated with APSAC (p less than 0.02). The mean time to treatment was 3.3 hours after symptoms of myocardial infarction for APSAC and 3 hours for placebo. The 30-day mortality was 7 patients in the placebo group and 1 in the APSAC group (p = 0.058). Adverse events were generally minor and were of similar overall frequency in both groups. There were more haemorrhagic events with APSAC, from which all patients recovered, and more cardiovascular events with placebo including 2 deaths from cardiogenic shock. APSAC showed a trend towards a reduction in 30-day mortality. Experience from this study has led to the initiation of the APSAC in myocardial infarction multicentre mortality study (AIMS).

The diagnosis of various forms of atrioventricular conduction disorder is considered in the light of intracardiac recording techniques. Criteria for the topographic diagnosis of AV block based on intracardiac recordings are described in this article.

We have investigated 13 patients with monomorphic ventricular tachycardia which originated from the right ventricular outflow tract. No patient had evidence of organic heart disease. There were 3 males and 10 females, aged 13-53 years. All had non-invasive investigations including an exercise electrocardiogram, chest radiography, echocardiograms and gated blood pool scintigraphy. Ten patients underwent cardiac catheterisation. Five patients had a prolonged QTc on their resting electrocardiogram. The remaining investigations showed no evidence of organic heart disease. Ten patients had ventricular arrhythmias which were completely suppressed during maximal exercise but which recurred in the immediate post-exercise period. A further 2 patients with no arrhythmias before exercise had ventricular tachycardia in the post-exercise period. Electrophysiology studies were performed in 5 patients with syncopal episodes, suggesting an automatic focus in 4. Four patients required specific antiarrhythmic surgery for symptoms refractory to medical therapy. Pace-mapping at operation confirmed the origin to be within the right ventricular outflow tract in all. Thus, we have identified a group of patients who have ventricular tachycardia originating from the right ventricular outflow tract in whom there is no apparent structural heart disease. Their arrhythmias are influenced by exercise and are probably due to an automatic focus. Four patients required surgery for ventricular tachycardias and recurrent syncopal episodes refractory to medical therapy.

The predictive accuracy of exercise thallium-201 (201Tl) myocardial scintigraphy in the evaluation of aortocoronary bypass graft surgery was assessed in 48 patients undergoing angiographic investigation 15 months (mean time) after myocardial revascularisation. 201Tl scintigrams detected 61 out of 77 (79%) patent grafts but only 21 out of 42 (50%) occluded grafts, though, for grafts supplying non-infarcted myocardium, the predictive accuracy of graft patency and graft occlusion was 85 per cent and 81 per cent, respectively. Stress electrocardiography failed to detect 15 out of 21 patients with scintigraphic evidence of regional myocardial ischaemia. Residual ischaemia in the proximal left anterior descending coronary distribution was commonly detected in 201Tl scintigrams despite a patent, well-functioning left anterior descending graft to the distal coronary segment. Additional residual ischaemia attributable to ungrafted coronary disease was detected by scintigraphy in 32 (67%) patients and most commonly occurred in the distribution of the diagonal branch of the left anterior descending especially in the presence of a patent distal left anterior descending graft. Thus, independent grafts to the diagonal branch of the left anterior descending are recommended at the time of aortocoronary bypass graft surgery.

One hundred and eight patients with single and multiple vessel coronary artery disease confirmed by arteriography were evaluated by exercise thallium-201 (201Tl) myocardial scintigraphy to determine the scintigraphic appearances of specific coronary stenoses. In general proximal stenoses caused more widespread, but not necessarily more severe, myocardial tracer deficit than distal stenoses. In particular, proximal dominant right coronary artery disease was specifically associated with extensive inferior wall tracer deficit in the anterior scintigram, whereas proximal left circumflex disease caused similar tracer depletion best visualised in the left lateral scintigram. A triad of uptake defects was caused by left anterior descending coronary artery disease: viz. apical tracer deficit (anterior view) in 71% lesions, septal tracer deficit (left anterior oblique view) in 83% of lesions, and anterolateral wall tracer deficit (left lateral projection) in 72% of lesions. The last defect has been termed a 'diagonal window' because it was associated with independent disease of the main diagonal branch of the left anterior descending coronary artery or with disease in the main left anterior descending artery situated proximal to this branch. Diagonal window tracer deficit was the most useful scintigraphic sign distinguishing proximal from distal disease in the left anterior descending coronary artery. False negative scintigraphic defects occurred more commonly in patients with triple vessel disease and in association with well-developed coronary collateral vessels. Certain scintigraphic patterns of 201Tl myocardial accumulation appear invaluable in the noninvasive localisation of stenoses within specific coronary arteries and thus may be useful in predicting life-threatening coronary artery disease which should be confirmed by definite coronary arteriography. The digital 201Tl myocardial scintigram also provides an independent functional guide to the interpretation of coronary arteriograms and may be helpful in the planning of aortocoronary bypass graft surgery.

Twenty-four patients have been treated for periods of up to two years (mean 14 months) with this single pass electrode for physiological pacing. Manufacturing refinements now allow percutaneous insertion into the subclavian vein. Pacing thresholds and sensing signals from both atrium and ventricle have remained satisfactory for a wide variety of different physiological pacemakers. No complications specifically related to the lead have occurred in a total of 277 patient months. We conclude that this single pass electrode is suitable for long-term implantation and can provide physiological pacing with present day stimulators.

A 27-year-old man had inferior myocardial infarction following superficial chest trauma. Coronary arteriography documented an isolated total occlusion of the right coronary artery, probably caused by localized extra-coronary compression, and no other evidence of intrinsic coronary disease. The left anterior descending artery later developed a localized proximal stenosis, most likely due to mural thrombus, which progressed rapidly to cause anterior myocardial infarction despite coronary artery surgery. The etiology of this lesion is discussed and support given to the "encrustation" hypothesis of human atherosclerosis. Exercise thallium scintigraphy proved helpful in the management of this case.