Successful reperfusion following thrombolysis results in increased heart rate variability in the first 24 hours after administration. Preservation of autonomic function may contribute to improved prognosis when coronary artery patency is restored with intravenous thrombolysis.

There can be few technical developments that have changed the face of interventional cardiology so much and so rapidly as the practice of placement of intracoronary stents. It is 10 years since the first stents were implanted in the coronary arteries of humans; since then, stenting has introduced challenges to every part of the health care system in the United Kingdom. First, the-placement of intracoronary stents is undoubtedly associated with a reduced rate of restenosis, both angiographic and clinical. Debate exists as to the magnitude of this effect and its possible relation to the diameter of the coronary artery stented, the length of lesion attempted, the morphology of the lesion, the clinical situation in which it is placed, and the design of the stent itself. However, these questions are not fundamental enough to deter the interventionalist from using the device widely. Second, and probably even more important in terms of the overall impact of stenting, the availability of a wide range of stents, both in design and physical dimensions, has enabled interventionalists to tackle a broad range of lesions within the coronary circulation. Cardiologists who have become conversant with stenting now regularly perform, as simple interventional procedures, cases that they would not have considered attempting four or five years ago. There is also strong evidence that stenting following reopening of chronic occlusions improves long term patency. Although multivessel angioplasty (PTCA) has long been advocated and practised by a few exponents, stenting has enabled this to become widespread and effective. Although 80% of PTCA in the UK is still for single vessel disease this percentage is decreasing. Stenting has also greatly reduced the risk for patients who are inoperable by conventional bypass surgery, so that advanced intervention and bypass surgery are complementary techniques. Third, stenting introduces an additional financial burden, which, in the UK at least, is proving difficult to cope with. The financial burden is exacerbated by the overall increase in interventional procedures stimulated by stent practice. There has been a huge growth over the past five years in the number of procedures performed annually in the UK. It is interesting to note that in the recent report of the Clinical Standards Advisory Group (CSAG) working group,' reforms in the health service would not seem to have had any real impact in the rate of growth of either PTCA or cardiac surgery. However, it has to be remembered that they have grown on average 10% per year, which is a more accelerated development than many other specialities within the health service that on average have grown only 2-3% per year. Despite this huge growth (approximately 20 000 procedures in 1996) there has been no real change in the numbers of cardiologists in the regional centres who perform probably the majority, but by no means all, of coronary interventional procedures in the UK. It is clearly a tribute to the profession that it has been able to absorb what is very large new workload, both in terms of time, and of course training and expertise. However, there is a finite limit to the amount of work that the existing practitioners can do, and so the growth of stenting and intervention is going to stress the training system and resources. The proliferation of stent devices, not to mention the many other interventional technologies, is also stressing the training and competence of the interventional cardiologist and trainees. The recent British Cardiovascular Interventional Society (BCIS) guidelines relating to training and competence have been controversial.2 Although there is no doubt that many procedures, including PTCA, can be performed by expert operators running at relatively low total numbers of procedures, that is true only if those operators are performing a narrow range of operations in terms of either patient selection or technical breadth. In a rapidly evolving and developing speciality such as coronary stenting it is simply not possible to be conversant with the various techniques available without performing quite large numbers of procedures each year. It is for these reasons that BCIS needs to have a very high profile, not only among its members (which includes nearly all interventionalists in the UK) but also with the various professional bodies, particularly the British Cardiac Society, the Royal Colleges and the Department of Health, to try to ensure that appropriate and sensible developments of service occur. Inequality and inequity have been widespread phenomena in the UK health care system, and this has been carefully and systematically documented by the recent CSAG report. This is borne out by recent BCIS audit of interventional procedures in the UK, showing that although the average rate of stent implantation in the country as a whole is approximately 30%, there is a range of 3-75% (BCIS audit returns 1996; unpublished data). The magnitude of this variation is simply too large and there is going to have to be a concerted effort both on the part of interventionalists, and purchasers and provider managers to resolve some of these issues. Despite these reservations there is no doubt that coronary stenting is a success story, and I think it is remarkable the extent to which it has already gained a foothold given the difficulties and constraints in the UK. There will always be an urgent need for rigorously carried out clinical trials and hopefully the current trials Department of Cardiology, Leeds General Infirmary, Great George Street, Leeds LSI 3EX, UK 19

It is generally accepted that plasma atrial natriuretic peptide release occurs secondary to atrial stretch. The influence of coordinated atrial contraction (AC) upon this process is not fully appreciated. The aim of the study was to determine the importance of coordinated AC upon peripheral atrial natriuretic peptide levels (α‐hANP) during exercise. Peripheral α‐hANP levels were measured at rest and during exercise in 12 patients with complete heart block (CHB) and permanent rate responsive pacemakers. Seven patients had coordinated AC and five had chronic atrial fibrillation (AE). Each patient performed three treadmill exercise tests. Maximal inspired oxygen volume (VO2 max) was determined during test 1. Tests 2 and 3 were performed to 70% VO2 max, the pacemaker being programmed to either VVI or VVIR mode. Plasma α‐hANP was measured using a two‐site immunoradiometric assay. At rest there was a small but significant difference between the two patient groups: AF 60.2 pg/mL versus AC 97.6 pg/mL; P = 0.03. During exercise in the AC patients, there was a significant increase in α‐hANP levels, in VVIR mode, to 238.4 pg/mL, and in VVI mode, to 207.9 pg/mL, P = 0.002 and 0.003, respectively. In those patients with chronic AF, there was no significant rise or fall in α‐hANP levels in either pacing mode, VVIR 65.2 pg/mL, VVI 46.6 pg/mL. Previous workers have suggested that α‐hANP release by nonfunctioning atria is normal. We have shown that the presence of coordinated AC is required for the release of α‐hANP during exercise in patients with CHB, and that this appears to be independent of ventricular rate.

This prospective study was conducted to determine the effect of Octreotide treatment on cardiovascular function in patients with active acromegaly. Ten acromegalic patients who failed to suppress growth hormone (GH) to < 5 mU/l during a 2 h oral glucose tolerance test were treated with 100 micrograms of Octreotide subcutaneously three times daily for 2 months, followed by 200 micrograms three times daily if the mean GH level was > 5 mU/l, for a total of 1 year. All patients had GH and insulin-like growth factor I (IGF-I) estimation, ejection fraction determined by Echocardiogram and multigated image acquisition scan, electrocardiogram (ECG), exercise ECG, 24-h ECG and chest x-ray. At 6 and 12 months, both GH and IGF-I were reduced but ECG, heart size and ejection fraction were unchanged. The patients improved symptomatically and had significant reduction in resting heart rate and increase in weight. Exercise time (mean +/- SD) increased from 637 +/- 137s at baseline to 787 +/- 101s at 1 year (p < 0.01) and work done increased from 9 +/- 3.3 to 11.9 +/- 2.7 metabolic equivalents (p < 0.001). We conclude that the decrease in GH and IGF-I following Octreotide treatment of acromegaly is accompanied by decreased heart rate and increased exercise capacity despite an unchanged ejection fraction.

Conference Abstract| July 01 1995 Early Classification of Type of Myocardial Infarction by Cardiac Enzyme Serum Profile P Kelly; P Kelly 1Department of Cardiology, Pinderfields Hospital, Wakefield, UK Search for other works by this author on: This Site PubMed Google Scholar P Walker; P Walker 1Department of Cardiology, Pinderfields Hospital, Wakefield, UK Search for other works by this author on: This Site PubMed Google Scholar A Ismail; A Ismail 1Department of Cardiology, Pinderfields Hospital, Wakefield, UK Search for other works by this author on: This Site PubMed Google Scholar I Wilson; I Wilson 1Department of Cardiology, Pinderfields Hospital, Wakefield, UK Search for other works by this author on: This Site PubMed Google Scholar E J Perrins E J Perrins 1Department of Cardiology, Pinderfields Hospital, Wakefield, UK Search for other works by this author on: This Site PubMed Google Scholar Clin Sci (Lond) (1995) 89 (s33): 15P. https://doi.org/10.1042/cs089015Pa Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Cite Icon Cite Get Permissions Citation P Kelly, P Walker, A Ismail, I Wilson, E J Perrins; Early Classification of Type of Myocardial Infarction by Cardiac Enzyme Serum Profile. Clin Sci (Lond) 1 July 1995; 89 (s33): 15P. doi: https://doi.org/10.1042/cs089015Pa Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu nav search search input Search input auto suggest search filter All ContentAll JournalsClinical Science Search Advanced Search This content is only available as a PDF. © 1995 The Biochemical Society and the Medical Research Society1995 Article PDF first page preview Close Modal You do not currently have access to this content.

Objectives. This study compared exercise and pharmacologic stress testing using arbutamine delivered by a closed-loop device for the detection of coronary artery disease.Background. Arbutamine, an agent designed to simulate exercise, has been developed in conjunction with a closed-loop delivery device that modulates the rate of administration on the basis of physiologic feedback.Methods. Two hundred ten patients (180 men, 30 women) with symptoms and angiographic evidence of coronary artery disease were studied. Ischemia was categorized in three ways: 1) the presence of angina; 2) the occurrence of greater than or equal to 0.1-mV horizontal or downsloping ST segment depression or elevation at 60 ms after the J point; or 3) the presence of either condition 1 or 2.Results. In the 210 patients, the mean increase in heart rate and systolic blood pressure evoked by arbutamine and exercise was 51 and 53 beats/min (p = NS) and 36 and 44 mm Hg (p < 0.0001), respectively. Arbutamine detected ischemia more often than exercise with each of the three ischemic end points. Sensitivity for detecting ischemia by either angina or ST segment change was 84% (95% confidence interval [CI] 79% to 89%) for arbutamine and 75% (95% CI 69% to 81%) for exercise testing (p = 0.014). For angina alone, sensitivity was 73% (95% CI 67% to 79%) for arbutamine and 64% (95% CI 57% to 71%) for exercise (p = 0.026). For ST segment change alone, sensitivity was 47% (95% CI 40% to 54%) far arbutamine and 44% (95% CI 37% to 51%) for exercise (p = 0.426). Cardiac events occurred in five patients (1.8%) within 24 h of the arbutamine test.Conclusions. In detecting documented coronary artery disease, the sensitivity of arbutamine testing was equal to that of exercise for the electrocardiographic end point of ST segment change alone. Arbutamine testing was significantly superior to exercise testing for either ST change or angina or for angina alone.

Conference Abstract| July 01 1995 Coronary Artery Reperfusion after Thrombolytic Therapy Maintains Early Heart Rate Variability P Kelly; P Kelly 1Departments of Cardiology, Pinderfields Hospital, Wakefield Search for other works by this author on: This Site PubMed Google Scholar J Nolan; J Nolan 1Departments of Cardiology, Pinderfields Hospital, Wakefield Search for other works by this author on: This Site PubMed Google Scholar J I Wilson; J I Wilson 1Departments of Cardiology, Pinderfields Hospital, Wakefield Search for other works by this author on: This Site PubMed Google Scholar E J Perrins E J Perrins 1Departments of Cardiology, Pinderfields Hospital, Wakefield Search for other works by this author on: This Site PubMed Google Scholar Clin Sci (Lond) (1995) 89 (s33): 15P. https://doi.org/10.1042/cs089015P Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Cite Icon Cite Get Permissions Citation P Kelly, J Nolan, J I Wilson, E J Perrins; Coronary Artery Reperfusion after Thrombolytic Therapy Maintains Early Heart Rate Variability. Clin Sci (Lond) 1 July 1995; 89 (s33): 15P. doi: https://doi.org/10.1042/cs089015P Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsClinical Science Search Advanced Search This content is only available as a PDF. © 1995 The Biochemical Society and the Medical Research Society1995 Article PDF first page preview Close Modal You do not currently have access to this content.

Conference Abstract| July 01 1995 Severity of Heart Failure Can be Assessed by Measurement of Atrial Natriuretic Peptides P Kelly; P Kelly 1Department of Cardiology, General Infirmary at Leeds Search for other works by this author on: This Site PubMed Google Scholar E Hunter; E Hunter 2Department of Biochemistry, Reading University Search for other works by this author on: This Site PubMed Google Scholar P Lowry; P Lowry 2Department of Biochemistry, Reading University Search for other works by this author on: This Site PubMed Google Scholar E J Perrins E J Perrins 1Department of Cardiology, General Infirmary at Leeds Search for other works by this author on: This Site PubMed Google Scholar Clin Sci (Lond) (1995) 89 (s33): 7P–8P. https://doi.org/10.1042/cs089007Pb Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Cite Icon Cite Get Permissions Citation P Kelly, E Hunter, P Lowry, E J Perrins; Severity of Heart Failure Can be Assessed by Measurement of Atrial Natriuretic Peptides. Clin Sci (Lond) 1 July 1995; 89 (s33): 7P–8P. doi: https://doi.org/10.1042/cs089007Pb Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsClinical Science Search Advanced Search This content is only available as a PDF. © 1995 The Biochemical Society and the Medical Research Society1995 Article PDF first page preview Close Modal You do not currently have access to this content.

A 63 year old man with symptomatic obstruction of the superior vena cava associated with an indwelling pacemaker was successfully treated with balloon venoplasty and stent insertion. He was symptom free with normal pacemaker function nine months later.

Objectives. The long term efficacy and safety of a third-generation implantable cardioverter-defibrillator implanted with thoracotomy and nonthoracotomy lead systems was evaluated in a multicenter international study.Background. The clinical impact of transvenous leads for nonthoracotomy implantation and pacing for bradyarrhythmias and tachyarrhythmias in implantable cardioverter defibrillator systems is not well defined.Methods. The safety of the implantation procedure and clinical outcome of 1,221 patients with symptomatic and life-threatening ventricular tachyarrhythmias who underwent implantation of a third generation cardioverter defibrillator using either a thoracotomy approach with epicardial leads (616 patients) or a nonthoracotomy approach with endocardial leads (605 patients) in a nonrandomized manner was analyzed. The implantable cardioverter defibrillator system permitted pacing, cardioversion, defibrillation, arrhythmia event memory and noninvasive tachycardia induction.Results. Successful implantation of an endocardial lead system was achieved in 605 (88.2%) of 686 patients and an epicardial system in 614 (99.7%) of 616 (p < 0.05). Perioperative 30 day mortality rate was 0.8% (1.8% including crossovers) in endocardial implant recipients compared with 4.2% (p < 0.001) in epicardial implant recipients(3.6% without crossovers, p < 0.05, respectively). Implantation mortality risk was significantly lower for nonthoracotomy systems irrespective of left ventricular ejection fraction or New York Heart Association functional class. Pacing therapies prevented need for cardioversion or defibrillation shocks in 89% of all ventricular tachycardia episodes and were comparably effective for both lead systems. Total survival rate at 2 years was significantly higher in endocardial (87.6%) than epicardial (81.9%) lead recipients (p < 0.001). Elimination of perioperative mortality from the analysis demonstrated comparable survival in both groups (p > 0.2).Conclusions. Third-generation cardioverter defibrillators with monophasic waveforms can be successfully implanted with epicardial (99.7%) and endocardial (88.2%) lead systems. We conclude that endocardial leads should be the implant technique of first choice. Improved patient management and tolerance for device therapy is achieved with the addition of antitachycardia pacemaker capability in these systems.

Twenty-two patients with dual chamber pacemakers with interchangeable lead configuration were exposed to 50 Hz electromagnetic interference. Current, at corporeal levels from 0-600 microA, was applied between electrodes on shoulders and feet using a bedside injection unit. Pacemaker behavior was monitored with telemetered event markers and intracardiac electrograms. In bipolar mode, noise reversion mode was induced in all except two Medtronic units at high (> 170 microA) levels of corporeal current. In the Intermedics, Siemens Pacesetter, and Telectronics models, onset of noise reversion mode was preceded by a window of inappropriate function, characterized by rate acceleration due to atrial malsensing, or pacemaker inhibition due to ventricular malsensing. In unipolar mode, pacemaker malfunction occurred at much lower current levels. Inappropriate behavior preceded the onset of protective noise reversion mode. During current injection, all pacemakers could be interrogated and reprogrammed, and intracardiac telemetry was reliably obtained except in two Medtronic units at high current levels. No pacemaker was reset by the electrical interference, and no cross-talk was seen. Use of bipolar mode confers a high degree of protection from extraneous electrical interference, but in unipolar mode pacemakers may be inhibited by small amounts of corporeal current, potentially encountered in every day life. The current injection unit allows safe, controllable, and quantifiable investigation of the effects of the electric field induced by a current on implanted pacemakers. Telemetry of annotated intracardiac signals during electromagnetic interference clarifies observations of pacemaker acceleration and inhibition.

Implantable automatic cardioverter/defibrillators are now commonly used to treat malignant ventricular arrhythmias.

Objectives-To study the differences between endocardial bipolar and unipolar ventricular paced evoked responses and surface electrocardiograms.Patient-10 patients with conduction system disease awaiting insertion of a permanent pacemaker were studied with temporary ventricular pacing from the right ventricular apex.Main outcome measure-Comparison of the durations of the QRS complexes and QTa and QTe intervals of the endocardial bipolar paced evoked response and the surface electrocardiogram with those of the reference unipolar paced evoked response.Results-By comparison with the unipolar reference, the mean durations of the QRS complexes of the bipolar signal and the surface electrocardiogram were 41.8% and 132.1% respectively. The mean QTa interval was 85.9% and 112.2% respectively and the mean QTe interval was 86.9% and 109.5% respectively. All these differences were significant. The amplitudes of the unipolar QRS complexes and T waves were significantly larger than those recorded in the bipolar configuration.Conclusions-Differences between the unipolar and bipolar ventricular paced evoked responses are significant. The time course of the unipolar signal is closer to that of the surface electrocardiogram. This indicates that the unipolar paced evoked response does not reflect local electrophysiological events, as has been suggested previously.

The relationship between blood pressure and platelet basal cytoplasmic calcium concentration ([Ca2+]i) and platelet sensitivity to aggregating agents in hypertension has been investigated in hypertensive patients and normotensive subjects. Ten severely hypertensive patients whose blood pressures were poorly controlled with metoprolol, were given calcium antagonist (either nifedipine or felodipine) as a second line agent. Venous blood samples were collected at each treatment phase for measurement, in whole blood, of platelet aggregation in response to ADP and collagen, and of basal [Ca2+]i using fura-2. Control of blood pressure by the combination of metroprolol and a calcium antagonist induced a significant decrease in median [Ca2+]i from 116 (76-181) to 73 (60-83) nM, which was similar to the median value of 70 (61-80) nM obtained in 14 normotensive subjects. Overall [Ca2+]i correlated with mean blood pressure (r = 0.51). Treatment of hypertension with calcium antagonist did not change the response of platelets to collagen or ADP. The results confirm that effective treatment of hypertension significantly reduced basal [Ca2+]i in platelets but raise doubts whether elevated basal [Ca2+]i is necessarily the sole mechanism by which the sensitivity of platelets to aggregatory agents is increased in hypertension.

Poorly controlled supraventricular arrhythmias in a hypokalaemic 74 year old woman were treated with oral amiodarone. This caused torsades de pointes, and was preceded by marked prolongation of the QT interval. The induction of torsades de pointes by amiodarone is thought to be an idiosyncratic reaction to amiodarone itself which is facilitated by electrolytic abnormalities. The present case, however, indicates the possibility of a pro-arrhythmic effect secondary to an interaction between amiodarone and digoxin.

Many studies suggest that patients who receive a ventricular pacemaker have a higher incidence of systemic thromboembolism compared to patients receiving a physiological pacemaker. However, the exact mechanism regarding the etiology of thromboembolism remains unclear. We evaluated the left atrial appendage (LAA) functions, using multiplane transesophageal echocardiography (TEE), in patients with different pacing modes. In order to evaluate the ejection fraction (EF), peak emptying (VE) and filling (VF) flow velocities of the LAA by TEE, we studied 31 patients (mean age 63±18.5 years) who had been paced for 5.0±2.9 years. Patients with atrial fibrillation, left ventricular dysfunction and mitral valve disease were excluded. The pacing indications were complete atrioventricular block (AVB) in 19 patients (9 VVI, 10 VDD or DDD) and sick sinus syndrome (SSS) in 12 patients (5 VVI, 7 DDD). Mean EF, VE and VF of the LAA were significantly lower in all patients with ventricular pacing (25.5±15.6%, 30.4±15.6 cm/s and 29.1±19.2 cm/s, respectively) compared to those with physiologic pacing (48.5±16.9%, 59.6±16.3 cm/s, 57.9±18.5 cm/s, respectively) (P<0.01 in all). When patients were further classified with respect to underlying heart disease whether they had SSS or AVB, all measurements of the LAA (EF, VE and VF) in both subgroup of patients with SSS and AVB were found significantly lower in those with ventricular pacing than in those with physiologic pacing (Table 3, Table 4). This decrease, especially in LAA flow, was much greater in those with SSS (Mean VE and VF <20 cm/s). In a patient paced with VVI for SSS, a thrombus was detected within the LAA cavity. In conclusion, these results suggest that the pacing modality appeared to influence the LAA functions in paced patients. Patients with asynchronous ventricular pacing modes had a significantly higher incidence of depressed LAA functions than did patients with physiological pacing, especially more marked in patients with sick sinus syndrome. This may be a factor responsible for increased risk of thrombus formation and thromboembolic events in this patient population.

Optimal functioning of a rate adaptive pacemaker depends upon reliable sensing of the sensor and appropriate programming of the rate response algorithm. QT sensing pacemakers use data derived from the endocardial electrogram in the programming of the rate response algorithm. In the latest versions of these pacemakers, programming of the rate response algorithm may be performed using either a semiautomatic Fast Learn (FLJ procedure or by using the newly developed, fully Automatic Slope Adaptation (ASA) mechanism. We report our experience in a prospective study of 17 patients in the first year postimplantation. ASA was characterized by significant changes only in the values of the slope settings at the lower rate limit (3.7 msec/msec at time 0 to 5.77 msec/msec at 2 weeks, P < 0.001) during the first 2 weeks after its enablement. Further adaptation between weeks 2 to 4 was observed (5.77 msec/msec to 6.4 msec/msec, P = 0.2) but this was not significant. The slope settings derived using the FL procedure were also checked at 2 and 4 weeks and were reproducible. They were closest in value to the values attained by the automated mechanism at 4 weeks. This suggests that the final value of the slope setting at the lower rate limit using ASA is reached between weeks 2 to 4. Both methods of slope determination result in satisfactory and similar rate response profiles but the time to achieve slope stability will necessarily be slower with ASA.

Conference Abstract| March 01 1991 Right Atrial Pressure Does Not Alter during Neck Suction in Humans G.C. Kaye; G.C. Kaye 1Department of Cardiology, Leeds General Infirmary, Leeds, UK Search for other works by this author on: This Site PubMed Google Scholar W. Baig; W. Baig 1Department of Cardiology, Leeds General Infirmary, Leeds, UK Search for other works by this author on: This Site PubMed Google Scholar E.J. Perrins E.J. Perrins 1Department of Cardiology, Leeds General Infirmary, Leeds, UK Search for other works by this author on: This Site PubMed Google Scholar Clin Sci (Lond) (1991) 80 (s24): 10P. https://doi.org/10.1042/cs080010Pa Views Icon Views Article contents Figures & tables Video Audio Supplementary Data Peer Review Share Icon Share Twitter LinkedIn Cite Icon Cite Get Permissions Citation G.C. Kaye, W. Baig, E.J. Perrins; Right Atrial Pressure Does Not Alter during Neck Suction in Humans. Clin Sci (Lond) 1 March 1991; 80 (s24): 10P. doi: https://doi.org/10.1042/cs080010Pa Download citation file: Ris (Zotero) Reference Manager EasyBib Bookends Mendeley Papers EndNote RefWorks BibTex toolbar search Search Dropdown Menu toolbar search search input Search input auto suggest filter your search All ContentAll JournalsClinical Science Search Advanced Search This content is only available as a PDF. © 1991 The Biochemical Society and the Medical Research Society1991 Article PDF first page preview Close Modal You do not currently have access to this content.