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The United Nations and the promotion of peace.

Despite the end of the cold war, many other conflicts persisted in the 1990s. The hope that a peace dividend would help to alleviate poverty was replaced by doubts regarding the effects of free market globalization and environmental constraints. Future concerns include the continuing aftermath of the cold war, the increased destructiveness of modern warfare, despite the increased sophistication of modern weaponry, the widening poverty gap between a wealthy elite and the majority of the world's population and developing global economic and environmental threats. The response to all this should be economic co-operation for sustainable development, including trade reform, and radical change in the environmental impact of the industrialized countries. Yet it appears that the response of the US, and to a lesser extent Europe, is to maintain the status quo in its own interests by military means, an attitude that seems to have been reinforced by the events of 11 September 2001. Nevertheless, these developments are opposed by citizen groups in the developed world and by analysts in the South. The United Nations and its agencies have been at the forefront of analysis and proposals for action in many of these fields. Its role is likely to increase in the next 30 years and it must be made as effective a global body as possible.

Environment↗

Long-term control of plasma calcitriol concentration in dogs and humans. Dominant role of plasma calcium concentration in experimental hyperparathyroidism.

Despite great interest in the elevated circulating levels of calcitriol (1,25-[OH]2D) associated with the clinical syndrome of human primary hyperparathyroidism, the relative potencies of known and potential stimuli/suppressors of long-term calcitriol levels have not been evaluated in either clinical or experimentally induced hyperparathyroid states. Based on reports that aparathyroid animals exhibit suppressed plasma calcitriol concentration and that acute administration of parathyroid hormone (PTH) to both humans and experimental animals or to renal slices in vitro results in increased plasma calcitriol concentration/production rate, it might be predicted that a chronic experimental model of either hypercalcemic primary hyperparathyroidism or hypocalcemic secondary hyperparathyroidism would show increased plasma calcitriol concentration. Chronic alterations in plasma calcium concentration have not been implicated as modulating calcitriol levels in any species. Accordingly, we investigated the long-term response of plasma calcitriol concentration in states of sustained experimental primary and secondary hyperparathyroidism. Intact dogs (group I) undergoing continuous intravenous PTH infusion for 12 d developed sustained hypercalcemia and hypophosphatemia, and plasma calcitriol concentration decreased from 23 +/- 3 to 14 +/- 3 pg/ml (P less than 0.01). Subsequent chelator (EGTA)-induced chronic normalization of hypercalcemia during ongoing PTH infusion resulted in a large and sustained increase in plasma calcitriol concentration to supernormal levels, reversible during subsequent cessation of chelator infusion. In additional intact dogs (group II), chronic chelator-induced hypocalcemic secondary hyperparathyroidism resulted in a sustained increase in plasma calcitriol concentration despite hyperphosphatemia. In normal human subjects undergoing a 12-13-d continuous intravenous PTH infusion to result in sustained moderate hypercalcemia (12.0 +/- 0.2 mg/100 ml) and hypophosphatemia, plasma calcitriol concentration decreased significantly (P less than 0.01) as in group I dogs and was followed by reversal to normal levels in a recovery period. The present results provide strong evidence in both humans and dogs that during experimentally induced chronic PTH excess, alterations in plasma calcium concentration dictate the directional response of circulating calcitriol concentrations. The long-term potency of plasma calcium concentration as a modulator of calcitriol metabolism is sufficient to override opposing modulation by plasma phosphorus concentration and PTH.

25-Hydroxyvitamin D 2↗

Ventricular arrhythmias: medical therapy, device treatment, and indications for electrophysiologic study.

Sustained ventricular arrhythmias occur most frequently during the first several months following MI, although the risk of arrhythmia development continues for many years. The mechanism responsible for most of these arrhythmias is a re-entrant circuit located in the border zone between the normal and scarred subendocardium. Clinical factors that identify patients at greatest risk for developing sustained ventricular arrhythmias after MI include depressed left ventricular function, acute left ventricular aneurysm formation, electrical instability, new bundle branch blocks, and residual ischemia. Attempts to lower the arrhythmic risk of these patients is a major area of clinical investigation. Although frequent asymptomatic ventricular ectopy and nonsustained ventricular tachycardia are risk factors for sudden death after infarction, it has not been demonstrated that empiric treatment of these arrhythmias with antiarrhythmic agents improves survival. Electrophysiologic studies have significantly contributed to understanding the mechanisms responsible for sustained ventricular arrhythmias. Although the role of electrophysiologic studies in guiding therapy in patients with sustained ventricular tachycardia or sudden death after infarction has been well established, their utility to identify high risk subgroups after infarction has not been conclusively determined. New treatment modalities have resulted in an improved outcome in patients with malignant ventricular arrhythmias (Table 2). These strategies include new pharmacologic therapies, arrhythmia surgery, use of automatic implantable cardioverter defibrillators or antitachycardia pacemakers, and percutaneous catheter ablation of the re-entrant circuit responsible for these arrhythmias.

Anti-Arrhythmia Agents↗

Clinical features of hepatocellular carcinoma that occur after sustained virological response to interferon for chronic hepatitis C.

BACKGROUND AND AIM: This study investigated the clinical features of hepatocellular carcinoma in patients with sustained virological response to interferon for hepatitis C viral (HCV) infection. METHODS: A total of 7,715 patients with HCV infection were treated with interferon and followed up for more than 1 year after withdrawal of interferon in 64 Japanese hospitals and clinics between July 1988 and August 2001. Sustained virological response was obtained in 2,515 (32.6%) patients. Of these 2,515 patients, clinical data were collected for 38 patients in whom hepatocellular carcinoma developed. Sustained virological response was defined as HCV RNA negativity more than 6 months after the termination of interferon. RESULTS: All patients were HCV RNA negative at the time of diagnosis of hepatocellular carcinoma. The median period until the detection of hepatocellular carcinoma was 4.7 years (range 1.4-9.0 years). There were significant improvements in hepatic function including serum albumin, aspartate aminotransferase, alanine aminotransferase, indocyanine green test, platelet count and histological activity grade in comparison with those before interferon therapy and at the onset of hepatocellular carcinoma. The maximum tumor size in patients without medical follow-up for 1 year or more (median: 60 mm) was significantly larger than in patients who were periodically followed up for 6 months or less (median: 25 mm) (P=0.002). CONCLUSIONS: The present findings emphasize the importance of regular medical follow up of patients with HCV infection, as even patients showing a sustained virological response to interferon and in whom hepatic function has improved have the potential to develop hepatocellular carcinoma.

Adult↗

Seawater type shapes larval development, intestinal microbiota, and water quality in Macrobrachium rosenbergii.

Giant freshwater prawn (Macrobrachium rosenbergii) has high economic value and extensive aquaculture prospects, and larval quality critically restricts the sustainable development of the industry. To investigate the effects of different seawater sources on larval survival and growth, artificial seawater, natural seawater from Beibu Gulf (China) and East China Sea (China) were used as culture media to compare their influences on larval development and intestinal microbiota of M. rosenbergii. Significant intergroup differences were observed in cultivation outcomes. The larval emergence rate reached the maximum value of 52.1% in Group G (Beibu Gulf natural seawater), followed by 43.57% in Group R (artificial seawater), and only 36.4% in Group Z (East China Sea natural seawater), indicating distinct larval emergence gaps and a gradual decline in larval development efficiency. Intestinal microbiota analysis indicated that Pseudomonadota, Actinomycetota and Bacillota were the dominant phyla in all three groups. The relative abundance of Bacillota increased significantly in Group G on day 10. LEfSe analysis proved that this group owned the most stable microbial structure and highest community diversity, and pronounced structural fluctuations occurred in Group R, suggesting that intestinal microbial profiles can reflect larval developmental conditions. Correlation analysis showed that gut microbial composition was closely correlated with water environmental parameters, and microbial metabolic pathways were strongly associated with larval growth and development. This study indicates that natural seawater from the Beibu Gulf of China is more suitable for healthy larval cultivation of M. rosenbergii. Structural stability and diversity of intestinal microbiota are key factors affecting larval growth. The results offer theoretical references for optimizing artificial seawater formula and improving larval rearing efficiency.

16S rRNA↗

Development of cardiac sympathetic and adrenal-medullary responses in borderline hypertensive rats.

Borderline hypertensive (BHR) rats are the first generation offspring of a cross of spontaneously hypertensive (SHR) and Wistar-Kyoto (WKY) normotensive rats. In adulthood, BHRs have systolic blood pressures in the 140-160 mm Hg range. If subjected to chronic stress paradigms, however, BHRs develop sustained and permanent elevations in systolic blood pressure (180-200 mm Hg). In the present study, we examined the functional development of cardiac and adrenal medullary responses to reflex activation of the sympathetic nervous system in preweanling BHR and WKY rats. Pups of the two groups were injected with insulin or saline at 4, 8, 12, or 16 days of age and sacrificed 3 h later. Insulin produces an acute lowering of blood glucose which is attended by a centrally mediated increase in sympathetic activity. The induction of ornithine decarboxylase (ODC) activity in heart and the depletion of epinephrine from the adrenal medulla were biochemical indicators of functional sympathetic neurotransmission. WKY and BHR pups had similar levels of cardiac ODC activity under basal conditions and following administration of insulin. In contrast, BHRs had higher amounts of adrenal norepinephrine and epinephrine from 4 to 16 days of age and greater depletion of adrenal epinephrine following insulin administration at 8, 12 and 16 days of age. These findings indicate that BHRs have a greater capacity for catecholamine biosynthesis, storage and release in the adrenal medulla during the preweanling period compared to age-matched normotensive WKY controls. This alteration in the adrenal medulla during the preweanling period may contribute to the susceptibility of adult BHR rats to stress-induced hypertension.

Adrenal Medulla↗

Electrophysiologic consequences of the Mustard repair of d-transposition of the great arteries.

This study describes the electrophysiologic effects of the Mustard repair of d-transposition of the great arteries on the sinus node and on conduction and refractoriness in the atrium, atrioventricular (AV) node and ventricle. Seventy-two electrophysiologic studies were performed on 64 patients after the Mustard operation. Standard rest and 24 hour ambulatory electrocardiograms were evaluated. Catheter endocardial atrial mapping, available in 67 of the 72 studies, revealed that sinus rhythm was present in the atria in 33 patients, ectopic atrial rhythm in 26 and junctional rhythm in 8. Intraatrial conduction delays with very late activation of the low medial, low lateral or low right atrium at the AV junction were present in 53 of 59 patients with atrial or sinus rhythm. Sinus node function was normal in only nine patients. Prolonged refractory periods were found in the right atrial portion of the new right atrium when compared with the left atrial portion of the new right atrium. Forty-one percent of the patients had prolongation of atrial refractoriness with shortening of the paced cycle lengths. Fifty-one percent developed sustained intraatrial reentry with programmed atrial stimulation. Forty-eight percent of these patients with inducible atrial tachycardia have since developed clinical episodes of atrial flutter. In summary, electrophysiologic studies revealed significant abnormalities of sinus node function and atrial conduction and refractoriness. Alone or in combination, these abnormalities, which result in severe bradycardia or rapid atrial arrhythmias, may lead to sudden death. The Jatene or arterial switch procedure may provide an appropriate alternative operation in this group of patients.

Adolescent↗

Ca(2+)-activated Cl(-) current in sheep lymphatic smooth muscle.

Freshly dispersed sheep mesenteric lymphatic smooth muscle cells were studied at 37 degrees C using the perforated patch-clamp technique with Cs(+)- and K(+)-filled pipettes. Depolarizing steps evoked currents that consisted of L-type Ca(2+) [I(Ca(L))] current and a slowly developing current. The slow current reversed at 1 +/- 1.5 mV with symmetrical Cl(-) concentrations compared with 23.2 +/- 1.2 mV (n = 5) and -34.3 +/- 3.5 mV (n = 4) when external Cl(-) was substituted with either glutamate (86 mM) or I(-) (125 mM). Nifedipine (1 microM) blocked and BAY K 8644 enhanced I(Ca(L)), the slow-developing sustained current, and the tail current. The Cl(-) channel blocker anthracene-9-carboxylic acid (9-AC) reduced only the slowly developing inward and tail currents. Application of caffeine (10 mM) to voltage-clamped cells evoked currents that reversed close to the Cl(-) equilibrium potential and were sensitive to 9-AC. Small spontaneous transient depolarizations and larger action potentials were observed in current clamp, and these were blocked by 9-AC. Evoked action potentials were triphasic and had a prominent plateau phase that was selectively blocked by 9-AC. Similarly, fluid output was reduced by 9-AC in doubly cannulated segments of spontaneously pumping sheep lymphatics, suggesting that the Ca(2+)-activated Cl(-) current plays an important role in the electrical activity underlying spontaneous activity in this tissue.

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

Canada's International Development Research Centre's eco-health projects with Latin Americans: origins, development and challenges.

BACKGROUND: Since its founding in 1970, Canada's International Development Research Centre (IDRC) has supported research by concerned Latin American researchers on environments and human health relationships. Framing of such relationships has changed through different periods. METHODS: Participant observation, bibliographic searches, document review, and interviews with key IDRC staff. FINDINGS: From the early years of multiple different projects, IDRC developed more focussed interest in tropical diseases, pesticides, agriculture and human health in the 1980s. The United Nations Conference on Sustainable Development in the early 1990s gave impetus to examination of links between ecosystems and human health or "EcoHealth". Projects in Latin America built on earlier work but extended it in methods (transdisciplinarity, community participation, gendered approach) and scope (broader land use and development paradigm issues tackled). A key IDRC-funded activity in Latin America was "EcoSalud", an Ecuadorian effort, which has worked with farming communities, agricultural researchers, health practitioners and local politicians to advance integrated pest management, better recognize and treat poisonings and improve pesticide-related policies. ONGOING CHALLENGES INCLUDE: mobilizing sufficient resources for the primary prevention focus of EcoHealth activities when primary care infrastructure remains stretched, promoting micro-level change in diverse communities and ecosystems, and addressing power structures at the global level that profoundly affect environmental change.

Agriculture↗

Development and health in the Pacific: which way to die?

Development in the Pacific has largely ignored the importance of health as a pathway and an outcome. This paper reviews the effects of development on health and health services in the region. It aims to highlight the plight of development that happens without considering the sociocultural and physical environments of the small island countries. The review shows that health and social conditions in the Pacific are deteriorating. The process of development has been externally controlled without community participation. Pacific leaders have been preoccupied with economic development and have not been cognisant of health and social consequences. During progress an enjoyable life can be achieved through sustainable development with community participation. However, indicators of economic growth in the Pacific do not correlate with those of health. The increase of rape, suicide, drug abuse, sexual promiscuity and crime suggests that Pacific islanders are increasingly disillusioned by the present developmental approach: they have ceased to enjoy life before death. It is suggested that decentralized development planning with community involvement, integrating health and social considerations, would be the way out of this dilemma.

Attitude to Health↗

Environmental health in Europe. A WHO perspective.

Concern about public health implications of environmental conditions in countries in the European region reached high political levels, demonstrated by European ministers of health and of environment protection at their second European Conference on Environment and Health, Helsinki, 20-22 June 1994. The report "Concern for Europe's Tomorrow", prepared by the WHO European Centre for Environment and Health was a basis for endorsing by the Conference an Environmental Health Action Plan for Europe and adopting a Declaration by which the ministers committed their governments to developing National Environmental Action Plans by the year 1997. Interactions between health and environment, integrated with policies and programmes for sustainable development, provide a unifying framework for a new public health.

Environmental Health↗

Wildlife resource utilisation at Moremi Game Reserve and Khwai community area in the Okavango Delta, Botswana.

This paper uses the concept of sustainable development to examine the utilisation of wildlife resources at Moremi Game Reserve (MGR) and Khwai community area (NG 18/19) in the Okavango Delta, Botswana. Using both secondary and primary data sources, results show that the establishment of MGR in 1963 led to the displacement of Khwai residents from their land; affected Basarwa's hunting and gathering economy; marked the beginning of resource conflicts between Khwai residents and wildlife managers; and, led to the development of negative attitudes of Khwai residents towards wildlife conservation. Since the late 1980s, a predominantly foreign owned tourism industry developed in and around MGR, however, Khwai residents derive insignificant benefits from it and hence resource conflicts increased. In an attempt to address problems of resource conflicts and promote sustainable wildlife utilisation, the Botswana Government adopted the Community-Based Natural Resource Management (CBNRM) programme, which started operating at Khwai village in 2000. The CBNRM programme promotes local participation in natural resource management and rural development through tourism. It is beginning to have benefits to Khwai residents such as income generation, employment opportunities and local participation in wildlife management. These benefits from CBNRM are thus having an impact in the development of positive attitudes of Khwai residents towards wildlife conservation and tourism development. This paper argues that if extended to MGR, CBNRM has the potential of minimising wildlife conflicts between Khwai residents and the wildlife-tourism sectors. This approach may in the process promote the sustainable wildlife use in and around MGR.

Animals↗

Fluctuation in autonomic tone is a major determinant of sustained atrial arrhythmias in patients with focal ectopy originating from the pulmonary veins.

INTRODUCTION: This study was designed to analyze dynamic changes in autonomic tone preceding the onset of sustained atrial arrhythmias in patients with focal atrial fibrillation (AF) to determine why patients with frequent discharge from the arrhythmogenic foci develop sustained AF. METHODS AND RESULTS: Holter tapes from 13 patients (10 men and 3 women; mean age 53 +/- 5 years) with paroxysmal "lone" AF (mean 18 +/- 13 episodes per week) and a proven focal origin (pulmonary veins in all cases) were analyzed. A total of 38 episodes of sustained (>30 min) were recorded and submitted to frequency-domain heart rate variability analysis. Six periods were studied using repeated measures analysis of variance: the 24-hour period, the hour preceding AF, and the 20 minutes before AF divided into four 5-minute periods. A significant increase in high-frequency (HF, HF-NU) components was observed during the 20 minutes preceding AF (P = 0.003 and 0.002, respectively), together with a progressive decrease in normalized low-frequency (LF-NU) components (P = 0.035). An increase in LF/HF ratio followed by a linear decrease starting 15 minutes before sustained AF also was observed, indicating fluctuations in autonomic tone, with a primary increase in adrenergic drive followed by a marked modulation toward vagal predominance immediately before AF onset. CONCLUSION: In patients with focal ectopy originating from the pulmonary veins, sustained episodes of atrial arrhythmias are mainly dependent on variations of autonomic tone, with a significant shift toward vagal predominance before AF onset.

Adult↗

A holosphere of healthy and sustainable communities.

Public health practice is in a transitory state, expanding considerably beyond medical and behavioural models of health and disease to encompass physical and social environmental health determinants. A new public health practice is emerging, apparent in initiatives like the international healthy cities/communities projects. This new public health practice must integrate the challenge of sustainable development, as defined by the 1987 World Commission on Environment and Development. The holosphere framework locates health as its central metaphor, and defines six interacting environmental spheres: a viable natural environment, a sustainable economic environment, a sufficient economy, an equitable social environment, a convivial community, and a livable built environment. There are five functional roles for local government: policy, legislation, education, partnerships and advocacy. Representative actions from each of the six environmental spheres of the holosphere framework are identified and discussed, using the five functional roles of local government. There is a need for new intersectoral forums to act upon the knowledge generated by integrative models such as the holosphere. Canadian Round Tables on Environment and Economy are encouraging examples of such intersectoralism.

Economics↗

Electrocardiographic response to intravenous urography: prospective evaluation of 275 patients.

A total of 275 consecutive patients referred for intravenous urography were monitored for electrocardiographic changes during administration of Conray 400 or Renovist II in the form of either intravenous bolus or infusion. Three patients who received Conray (two bolus and one infusion) developed sustained ventricular tachycardia; they reverted to sinus rhythm with intravenous lidocaine. A statistically significant (P less than .05) number of patients developed a heart rate increase of 10 beats/min or more with bolus of either drug (65 of 128) compared to infusion (21 of 147). Depression of ST segment (greater than or equal to 0.5 mm) was encountered statistically more often (P less than .05) with bolus (20 of 128) compared to infusion (six of 147). Increase of corrected QT of 0.10 sec or more was observed more often (P less than .05) with bolus (43 of 128) compared to infusion (five of 147). Abnormal resting ECG, coronary artery disease, or congestive heart failure imposed a higher (P less than .05) risk for development of ventricular tachycardia, ST depression, or ectopic ventricular beats. It is concluded that a bolus injection be very cautiously administered to patients with risk factors such as abnormal ECG, coronary artery disease, or congestive heart failure during intravenous urography and that resuscitative facilities be available.

Adolescent↗

Commissioning. Building the builders.

Continual structural changes have hampered the development of the commissioning function. A new development programme is helping commissioners form networks and move away from outdated approaches. Evidence suggest commissioners benefit greatly from networking and sustained development opportunities.

Health Care Reform↗

Apolipoprotein E-deficient mice created by systemic administration of antisense oligodeoxynucleotides: a new model for lipoprotein metabolism studies.

Atherosclerotic cardiovascular disease results from complex interactions among multiple genetic and environmental factors. Thus, it is important to elucidate the influence of each factor on cholesterol metabolism. For this purpose, transgenic/gene-targeting technology is a powerful tool for studying gene functions. However, this technology has several disadvantages such as being time consuming and expensive. Accordingly, we established new animal models using in vivo gene transfer technology. In this study, we examined the feasibility of the creation of a new animal model for the study of atherosclerosis. We hypothesized that apolipoprotein (apo) E-deficient mice can be created by systemic administration of antisense apo E oligodeoxynucleotides (ODN) coupled to the HVJ-liposome complex. Initially, we examined the localization and cellular fate of FITC-labeled antisense ODN administered intravenously. FITC-labeled ODN transfection by the HVJ-liposome method resulted in fluorescence in the liver, spleen and kidney, but not in other organs such as brain. Moreover, fluorescence with the HVJ-liposome method was sustained for up to 2 weeks after transfection, which resulted in a striking difference from transfection of ODN alone or ODN in liposomes without HVJ, which showed rapid disappearance of fluorescence (within 1 day). Given these unique characteristics of the HVJ-liposome method, we next examined transfection of antisense apo E ODN by intravenous administration. Transfection of antisense apo E ODN resulted in a marked reduction of apo E mRNA levels in the liver, but no change in apo B and beta-actin mRNA levels. In mice fed a normal diet, a transient increase in cholesterol and triglyceride levels was observed in the antisense apo E-treated group, but they returned to normal levels by 6 days after transfection. Similar findings were also found in mice fed a high cholesterol diet. Neither scrambled nor mismatched ODN resulted in any increase in cholesterol. To make chronic hypercholesterolemic mice, we therefore performed repeated injections of apo E antisense ODN. Whenever antisense apo E ODN were injected, mice showed a transient increase in cholesterol and triglyceride. Cumulative administration of antisense apo E ODN resulted in a sustained increase in cholesterol for up to 3 weeks after the last transfection. Finally, mice treated with repeated injections of antisense apo E every week developed sustained hypercholesterolemia and hypertriglyceridemia until withdrawal of injections. Apolipoprotein-deficient mice created by intravenous administration of antisense ODN are a promising new animal model to help understand the role of apolipoprotein in vivo and develop a new drug therapy targeting apolipoprotein.

Animals↗

Results of electrophysiological testing and long-term follow-up in patients sustaining cardiac arrest only while receiving type IA antiarrhythmic agents.

UNLABELLED: Therapeutic management of patients sustaining a cardiac arrest while receiving antiarrhythmic agents can be difficult since the role of the drug in possibly facilitating the arrhythmia is often difficult to define. To determine if the response to programmed stimulation could give insight into which patients may have experienced a drug-induced cardiac arrest, we studied 29 patients (61 +/- 9 years) with no prior history of sustained ventricular tachyarrhythmias (VT) who suffered a cardiac arrest only while receiving type Ia antiarrhythmic agents. Patients with documented myocardial infarction, acute ischemia, electrolyte abnormalities, or torsade de pointes were excluded from the study. Twenty-four patients had coronary artery disease with prior myocardial infarction (ejection fraction 28% +/- 9%) and five patients had idiopathic dilated cardiomyopathy (ejection fraction 31% +/- 6%). During baseline electrophysiological testing, 19 patients (66%) had inducible sustained ventricular arrhythmias: uniform VT, n = 14 (group I), polymorphic VT or ventricular fibrillation, n = 5 (group II). Ten patients (group III) had no inducible sustained ventricular arrhythmias. To determine if rechallenge with a type Ia agent could facilitate induction of a sustained ventricular arrhythmia in group III, eight patients underwent ten electrophysiological studies during therapy with either procainamide or quinidine. Only two patients developed sustained VT in response to programmed stimulation. Patients in groups I and II received therapy guided by electrophysiological testing, including antiarrhythmic agents alone (n = 8), subendocardial resection (n = 4), or an implantable cardioverter defibrillator (n = 7). Patients in group III received antiarrhythmic agents empirically (n = 3), or for treatment of atrial tachyarrhythmias (n = 2) or nonsustained VT (n = 1). In addition, four patients in group III received an implantable cardioverter defibrillator. During a mean follow-up of 28 +/- 27 months (range: 1 day-84 months) 13 patients died suddenly or received a defibrillator shock preceded by syncope or presyncope: group I: n = 5; group II: n = 2; group III: n = 6. IN CONCLUSION: (1) most patients sustaining a cardiac arrest only in the presence of type Ia antiarrhythmic agents have inducible sustained VT in the absence of antiarrhythmic agents, and (2) the risk of recurrent VT persists in patients without inducible sustained arrhythmias in the drug-free state, regardless of whether they manifest inducible arrhythmias after rechallenge with a type Ia agent.

Aged↗