THE CHANGING OUTLOOK IN CORONARY DISEASE

The statistical prognosis for patients who survive a first attack of coronary thrombosis, as regards both life expectancy and ability to return to normal activity, has been greatly improved in recent years. In the light of advances in understanding of the physiology of the heart and improvements in therapeutic methods, physicians must reevaluate ideas of what a patient should be permitted to do after recovery from an initial attack. Often a return to normal pursuits may be better for the patient than drastic restriction of activity, particularly because of the psychological and emotional effects of invalidism.In deciding what advice to give on this score, the physician should consider in each case not only the actual amount of coronary circulation but such factors as the patient''s temperament, type of occupation and economic status. The goal should be to guide each patient back to usefulness within the limits of his cardiac reserve.     

Simultaneous robotic-assisted mitral valve repair and percutaneous coronary intervention

We present a case report of a robotic-assisted mitral valve repair with simultaneous percutaneous coronary intervention. A 58-year-old man presented with New York Heart Association class III symptoms from severe mitral regurgitation and significant stenosis of the right coronary artery. In a hybrid operating theater, the patient underwent placement of a bare metal stent in the right coronary artery followed immediately by robotic-assisted mitral valve repair. Both procedures were successful and occurred in a timely fashion. The patient experienced no immediate postoperative complications and was discharged home on postoperative day 5. At 2-week follow-up, he had returned to his normal activities of daily living and at 1 year remained asymptomatic. This case report demonstrates the benefits of minimally invasive robotic mitral valve repair in allowing for successful repair, early postoperative return to activity, minimal incision pain, and high patient satisfaction. It further highlights the potential benefit of a hybrid operating theater in allowing surgical and percutaneous coronary intervention procedures to be delivered in a safe and efficient manner.     

The national framework and consequence management guidance following a biological attack

Consequence management following a release of aerosolized Bacillus anthracis spores requires a high level of technical understanding and direction. National policies and regulations address the topics of preparedness goals and organizational structure, but they do not tell responders how to perform remediation. Essential considerations include determining what must be cleaned, evaluating health risks, ascertaining the priority of cleanup, and selecting appropriate decontamination technologies to meet consensus and risk-derived clearance goals. This article highlights key features of a national-level framework that has been developed to guide a risk-based decision process and inform technical personnel of the best practices to follow during each activity leading to the restoration of functions at affected facilities or areas. The framework and associated guidance follows the scheme of 6 phases for response and recovery arrived at through interagency consensus and approval. Each phase is elaborated in a series of detailed decision flowcharts identifying key questions that must be addressed and answered from the time that first indications of a credible biological attack are received to final reoccupancy of affected areas and a return to normal daily functions.     

Ambulant management of patients with recent myocardial infarction.

Thirty-two patients who had remained ambulant and active after suffering an acute myocardial infarction were observed for 6 months. Complications were present initially in 11 but proved transient. One patient died of a new coronary thrombosis 15 weeks after the initial episode. There were no recurrences among the 31 surviving patients. After the 6 months all but two patients were as well as before the attack; 21 were free of symptoms and there was no undue incidence of objective findings that could be attributed to failure to rest after the attack. It is therefore concluded that, for patients who suffer an acute myocardial infarction, immediate diagnosis and admission to a coronary care unit need not be equated invariably with immobilization in bed. Our experience suggests that selected patients can be allowed moderate activity without ill effects and thus avoid the undesirable consequences of enforced bed rest.     

Dobutamine stress magnetic resonance imaging suffices for the demonstration of myocardial ischaemia and viability

We report three patients in whom dobutamine stress magnetic imaging (DS-MRI) was essential in assessing myocardial ischaemia. Two patients were referred to the cardiologist because of chest pain. Patient A had typical exertional angina and a normal resting electrocardiogram (ECG). Patient B had typical exercise-induced angina and had recently experienced an attack of severe chest pain at rest for 15 minutes. The ECG showed a complete left bundle branch block (LBBB). Patient C was referred for heart failure of unknown origin. There were no symptoms of chest pain during rest or exercise. Echocardiography in this patient demonstrated global left ventricular (LV) dilatation, systolic dysfunction and a small dyskinetic segment in the inferior wall. In all these patients exercise stress testing had failed to demonstrate myocardial ischaemia. Patients A and C produced normal findings whereas in patient B the abnormal repolarisation due to pre-existent LBBB precluded a diagnosis of ischaemia.Breath-hold DS-MRI was performed to study LV wall motion and wall thickening at rest through increasing doses of dobutamine. A test was considered positive for myocardial ischaemia if wall motion abnormalities developed at high-dose levels of the drug (20 μg/kg/min or more with a maximum of 40 μg/kg/min) in previously normal vascular territories or worsened in a segment that was normal at baseline. Recovery of wall thickening in a previously hypokinetic or akinetic segment at a low dose of dobutamine (5-10 μg/kg/min) was taken as proof of viability.Patients A and B developed hypokinesia progressing into akinesia at high-dose dobutamine in the anteroseptal area of the LV indicative of ischaemia. These findings were corroborated by coronary angiography demonstrating severe coronary artery disease which led to coronary artery bypass grafting (CABG) in patient A and balloon angioplasty in patient B. In patient C global recovery of LV contractions during low-dose dobutamine was followed by hypokinesia in the inferoseptal area during high-dose dobutamine. This biphasic response indicates myocardial viability as well as ischaemia. CABG was carried out because of multiple stenoses in the left coronary artery. Post-operatively LV function normalised.DS-MRI is a valuable method for detecting myocardial ischaemia and viability in patients with suspected coronary artery, and can be applied in every hospital with MRI equipment at its disposal.     

Physical activity and stroke in British middle aged men.

OBJECTIVES--To assess the relation between physical activity and stroke and to determine the overall benefit of physical activity for all major cardiovascular events. DESIGN--Prospective study of a cohort of men followed up for 9.5 years. SETTING--General practices in 24 towns in England, Wales, and Scotland (British regional heart study). SUBJECTS--7735 men aged 40-59 at screening, selected at random from one general practice in each of 24 towns. MAIN OUTCOME MEASURES--Fatal and non-fatal strokes and heart attacks. RESULTS--128 major strokes (fatal and non-fatal) occurred. Physical activity was inversely associated with risk of stroke independent of coronary risk factors, heavy drinking, and pre-existing ischaemic heart disease or stroke (relative risk 1.0 for inactivity, 0.6 moderate activity, and 0.3 vigorous activity; test for trend p = 0.008). The association remained after excluding men reporting regular sporting (vigorous) activity. However, vigorous physical activity was associated with a marginally significant increased risk of heart attack compared with moderate or moderately vigorous activity in men with no pre-existing ischaemic heart disease or stroke (relative risk 1.6%; 95% confidence interval 0.96 to 2.8). In men with symptomatic ischaemic heart disease or stroke those doing moderately vigorous or vigorous activity had a risk of heart attack slightly higher than that in inactive men (relative risk = 1.6; 0.8 to 3.3). CONCLUSIONS--Moderate physical activity significantly reduces the risk of stroke and heart attacks in men both with and without pre-existing ischaemic heart disease. More vigorous activity did not confer any further protection. Moderate activity, such as frequent walking and recreational activity or weekly sporting activity, should be encouraged without restriction.     

Individualized workup: a new approach to the biochemical diagnosis of acute attacks of neuroporphyria

Porphyria experts concur that acute attacks of AIP, VP and HCP, are invariably associated with increases in urinary PBG. Reports differ, however, as to the amount of increase indicative of an acute attack. Some authors consider excretion of at least 25-fold the upper level of normal, as indicative, whereas others regard a 10-fold or even a 2-fold increase, as sufficient indication. An additional diagnostic difficulty arises from the fact that in many individuals known to have inherited one of the acute porphyrias, PBG is persistently raised also during remission. It may be markedly elevated even in asymptomatic carriers. In the absence of a universally accepted standard for interpreting PBG results, attribution of neurovisceral or neuropsychiatric symptoms in porphyrics to an acute attack of porphyria rather than to other causes, depends largely on clinical assessment. The aim of this work was to identify reliable criteria, which will enable establishing or excluding an acute attack, on a biochemical basis. The study summarizes and interprets data obtained during classical neurovisceral acute attacks and latent phases in 20 patients (10 with AIP, 6 with VP, and 4 with HCP). Calculated increases in urinary PBG, with the upper limit of normal excretion, (8.8 micromol/24 h), defined as 100 %, revealed an overlap between values in the acute and latent phases, (1 to 18.5-fold and 2.3 to 51-fold, respectively). This overlap indicates that the workup in each case needs to be individualized. We achieved this goal, by using another method of calculation, in which the PBG value measured during an acute attack in a particular patient was divided by the PBG value measured in that patient's latent phase. Increases of 2.3 to 50.5-fold were obtained, leading to the conclusion that any increase, calculated as above, of 2.3-fold and higher, may be taken as indicative of an acute attack. An additional finding, demonstrated in the study, which might be useful for supporting the diagnosis of an acute attack, is the distinct emission peak observed at 404/621 nm, in the plasma fluorometric scan of AIP and HCP patients, during an acute attack. We conclude that comparison of the urinary PBG level and plasma fluorometric scan in the acute phase to those of the latent phase in the individual patient is the key to correct, accurate and reliable biochemical diagnosis of an acute attack in a patient previously diagnosed as a porphyric. The additional tests required for confirming a patient's first acute attack, having no data to compare with, are discussed.     

Cold pressor test in diagnosis of coronary artery disease: echophonocardiographic method.

The cold pressor test was used to induce myocardial ischaemia in patients with coronary artery disease and the rise in left ventricular filling pressure used as the index of myocardial ischaemia. Left ventricular filling pressure was derived from a non-invasive echophonocardiographic method. A study group of 19 consecutive patients with chest pain underwent the cold pressor test before coronary angiography. Eighteen responded with a rise in filling pressure exceeding 30% and, of these, 17 had serious coronary artery disease (three single vessel, one two vessel, and 13 triple vessel disease; one had coronary artery spasm only). The remaining patient, who showed no rise in filling pressure, did not have coronary artery disease. None of 15 normal controls showed a rise greater than 5% (patients with coronary artery disease versus normal controls p less than 0.001). The cold pressor test would be suitable for patients who cannot or should not exercise and may be combined with exercise electrocardiograms to improve the information content, as it uses a different marker of myocardial ischaemia.     

Troponin elevation in patients with various tachycardias and normal epicardial coronaries

Troponin elevation is usually synonymous with acute coronary syndrome (ACS). Although sensitive for ACS, the elevation of serum troponin, in the absence of clinical evidence of ischemia, should prompt a search for other etiologies of myocardial necrosis. In fact, elevated values of troponin are correlated with myocardial necrosis even though it does not discriminate the mechanism involved. We report a series of seven patients (age range 18-67 years), who presented with complaints of chest discomfort and were found to have regular supraventricular tachycardia (5 patients) and one patient each with atrial fibrillation and ventricular tachycardia. All these patients had elevated troponin I and underwent coronary angiography that revealed normal epicardial coronary arteries. This is first case series in which all patients underwent coronary angiography and none of the patients was hemodynamically unstable at the time of presentation. Patients with elevated troponin due to conditions other than ACS can receive inappropriate and delayed definitive diagnosis and treatment.     

Guidelines for indications for coronary revascularization in The Netherlands

In 1996 the Minister of Public Health, Welfare and Sports in The Netherlands published a 'Planning Decree Special Interventions in the Heart'. She requested from the professional organizations guidelines for the indications for interventions in the heart. A working group was formed with representatives from the Dutch professional organizations for cardiology and thoracic surgery, to address this issue for patients with coronary artery disease. The working group confirmed the need to discuss all patients who are considered for either elective or emergency revascularization during a multidisciplinary consultation in (or with) one of the specialized Dutch hospitals. During this meeting of the 'heart team', at least one interventional cardiologist and one thoracic surgeon should be present. There are three possible outcomes of the heart team's consultations for each patient: drug therapy only ('conservative management'), coronary surgery or catheter intervention. For each case, the team should indicate the expected benefit, the risk of the intervention, the urgency and the estimated waiting time. The guidelines presented in this paper address these issues for three patient categories: stable angina pectoris, unstable angina pectoris and acute myocardial infarction.     

A note on fear reaction of three different genetic strains of laying hens to a simulated hawk attack in the hen run of a free-range system

Hens well adapted to free-range systems should react quickly to avoid an attack by a predator but should also be able to return to the hen run soon after to ensure good use of the outside area. To ascertain if some strains cope better with a frightening event the fear reaction of three different genetic strains to a simulated hawk attack in a free-range system was tested. Eight groups of 21 hens composed of the three different strains (LSL, ISA brown and ISA black), were exposed to a simulated hawk attack. Fear reaction and recovery times were video recorded and the use of the hen run was observed. Although the hens did react to the simulated hawk attack as expected by running back into or in direction to the poultry house, no significant strain differences were found either in the reaction or recovery time or in the course of the hen run used. Regarding fear reaction no strain was found to have better features for use as free-range laying hen regarding the behaviour after a frightening event.     

PEDIATRIC ANESTHESIA

Induction of anesthesia in infants and children presents many problems not present in procedures for adults. Anesthetists may better serve the patient by visiting with him on the eve of operation, not only to establish friendly relations to avoid rebellion, but to form a basis for decision as to what anesthetic agent to use and by what method it should be given. As the kind of operation and the difficulties to be expected with each are large factors in the choice of agent and technique, a number of operative situations are reviewed from this standpoint.     

NEGATIVE TREADMILL EXERCISE TEST RESULT WITH SUBSEQUENT MYOCARDIAL INFARCTION AND CORONARY ARTERY BYPASS: CASE REPORT

Myocardial infarction is a rare complication of maximal exercise testing.(1) In the case presented here, infarction occurred in a 54-year-old man, 14 minutes after he showed a normal response to maximal multistage treadmill exercise testing. The presence of coronary artery disease had been documented angiographically prior to exercise testing. After infarction, the patient underwent emergency double aortocoronary bypass to the left anterior descending and right coronary arteries with good results. Clinical evidence suggests that the extent of myocardial necrosis was reduced by timely surgical intervention. There is no conclusive explanation for this patient's normal response to maximal exercise testing in the presence of advanced coronary artery occlusive disease followed rapidly by infarction. The value of exercise testing is well established in assessing the existence or severity of coronary artery disease; a normal response, however, cannot be used as an infallible indication that critical coronary artery disease does not exist.     

Pediatric anesthesia

Induction of anesthesia in infants and children presents many problems not present in procedures for adults. Anesthetists may better serve the patient by visiting with him on the eve of operation, not only to establish friendly relations to avoid rebellion, but to form a basis for decision as to what anesthetic agent to use and by what method it should be given. As the kind of operation and the difficulties to be expected with each are large factors in the choice of agent and technique, a number of operative situations are reviewed from this standpoint.     

Preoperative evaluation of the cardiac patient for noncardiac surgery.

Perioperative cardiac events continue to represent a significant cause of morbidity in patients undergoing noncardiac surgery. The evaluation of the high risk patient should begin with an assessment of the probability of coronary artery disease and exercise tolerance. Decisions to undergo further evaluation, including noninvasive testing, should be based upon the perioperative morbidity and mortality rate for the planned surgical procedure. In patients with significant coronary artery stenoses and a high probability of perioperative cardiac morbidity, coronary artery bypass grafting, percutaneous transluminal coronary angioplasty, and preoperative optimization of hemodynamics in an intensive care unit have all been advocated as means of reducing risk.     

Metabolism of coronary vasculature in euthyroid, hyperthyroid and recovering hyperthyroid rats: a histochemical study

Coronary arteries and arterioles from normal rats, from rats made hyperthyroid by administration of desiccated thyroid for 10 weeks, and from hyperthyroid rats which were then fed normal control diets for 10 weeks, were examined histochemically to determine the activity of key metabolic pathways. The primary aims of this study were to determine if the alterations in particular enzyme and substrate activities that occur in thyrotoxic rat myocardium, arteries and arterioles were reversible and would return to normal levels following cessation of the hyperthyroid state. Our results suggest that hyperthyroid rats, even after 10 weeks on the normal diet, still show some compromise in arteriolar aerobic metabolism in favor of anaerobic pathways, while coronary arteries still demonstrate little glucose-6-phosphate dehydrogenase activity. Myocardial metabolic activity approximates that of normal control animals by the end of the 10th week on the normal diet.     

Are coronary artery spasm and progressive damage to the heart associated with the hyperventilation syndrome?

A case of coronary artery vasospasm was studied in a man with a four year history of angina. He had evidence of symptomatic hyperventilation during a spontaneous episode of chest pain. When asked to hyperventilate the pain in his chest and ST elevation were reproduced in the same leads as occurred during the spontaneous attack. This may be the first reported case of spontaneous hyperventilation producing vasoconstriction, and the patient''s previous admissions to the coronary care unit may have been associated with coronary vasospasm induced by hyperventilation. When patients with variant angina report pains in the chest in association with dizziness and breathlessness hyperventilation should be considered to be a possible cause of the symptoms. As coronary vasospasm is increasingly implicated in angina after myocardial infarction the role of hyperventilation should be considered more often.     

Theory and practice of decision making in coronary care in general practice.

Decisions about coronary care made by 39 randomly selected general practitioners in New Zealand over one year were investigated. Demographic variables and variables relating to the patient''s condition, history, and social circumstances were assessed for 113 patients, and practitioners'' belief about the relevance of each variable to the decision was elicited. A comparison was made between the objective criteria found to be related to the decision, the criteria believed by the practitioners to be relevant to the decision, and a theoretical model of what should govern the decision to admit. The theoretical model was found to be built into the beliefs of the practitioners, but the objective model was far simpler. Further research is needed to determine whether the use of the more complex, theoretical models will confer any benefit, in terms of patient wellbeing, over the pragmatic model in use at present.     

NONCARDIAC SURGERY COMBINED WITH CORONARY ARTERY BYPASS

The coexistence of coronary artery disease with noncardiac disease often leads to a dilemma in planning therapeutic procedures. This problem is especially difficult in the presence of accelerated angina or left coronary artery stenosis. A series of 17 patients is presented in which coronary artery bypass grafts were combined with noncardiac operations without mortality or significant morbidity. An illustrative case report shows the interrelated nature of the coexisting disorders. The conclusion of this study is that, at times, various surgical procedures should be combined with coronary artery bypass grafting for a smoother, less complicated recovery. However, there are no hard and fast rules dictating combined procedures; each operation must be planned according to the existing conditions and needs of the individual patient.     

Immunological reason for chronic ill health after infectious mononucleosis.

In a group of patients who suffered from chronic ill health after an attack of acute infectious mononucleosis a disorder of T cell regulation was found. By means of cytochemical reactions the staining pattern associated with T suppressor cells was found in a greater percentage and that associated with T helper cells in a smaller percentage than in normal subjects. In a few patients this finding was confirmed in a functional suppressor assay. The patients were unwell for at least a year but most later made a complete recovery, which was associated with return to normal of the lymphocyte subsets.