Seasonal variations in myocardial infarctions and the possible biotropic influence of short-period geomagnetic pulsations on the human cardiovascular system

Analysis of ambulance calls in Moscow during 1979–1981 reporting myocardial infarction (85 700 events), sudden death (71 700 events), and hypertension crises (165 500 events) shows the presence of clear seasonal variations with a deep summer minimum and a winter maximum. The same trend was upon analysis of monthly data on infarction mortality in Bulgaria over 15 years (1970–1985). One of the biotropic factors influencing the human cardiovascular system can be geomagnetic pulsations Pc1, agreeing in frequency with cardiac rhythms. In the seasonal trend, Pc1 have maximum intensity in winter. The comparison of data on ambulance calls in Moscow with the Pc1 observation data catalog revealed that, on ～70% of days, an abnormally large number of myocardial infarction calls was accompanied by the presence of Pc1; their concurrence was half again the chance expectation. Besides, it was determined that the biotropic influence of magnetic storms in winter was much higher than in summer. One of the plausible reasons of the winter infarction maximum could be seasonal variations in the production of the pineal hormone melatonin, which destabilized the organism and increased its sensitivity to geomagnetic disturbances attended by Pc1.     

Biotropic effects of geomagnetic storms and their seasonal variations

A substantial effect of geomagnetic storms on human health with a confidential probability P = 0.95 was revealed. The quantitative estimates of the biotropic effect are presented. For example, the frequency of occurrence of bursts exceeding the average number of hospitalized patients with mental and cardiovascular diseases during magnetic storms increases approximately 2 times compared with quiet periods (based on the data on 1983-84). The frequency of occurrence of myocardial infarction, angina pectoris, violation of cardial rhythm, acute violation of brain blood circulation during storms increases 2.1; 1.6; 1.6; 1.5 times, respectively compared with magnetically quiet periods (based on the data of 1992-96). A similarity of the seasonal distribution of the magnitude of the biotropic effect is revealed in the case of myocardial infarction and the number of magnetic storms: a maximum in the equinox and a minimum in summer.     

药物涂层支架与金属裸支架治疗ST段抬高型心肌梗死的临床价值比较

目的：评价药物涂层支架（DES）与金属裸支架（BMS）在急性心肌梗死患者中应用的安全性和有效性。方法：选择2003年1月-2010年12月,在我院确诊的急性sT段抬高型心肌梗死（STEMI）167例患者,其中使用BMS65例,DES102例。对比分析两组患者住院期间和出院后1年内的主要心血管或脑血管事件（MAACE）的发生情况及支架内血栓形成的发生率。结果：至随访结束,BMS组有1例患者猝死,5例出现复发心绞痛。DES组有1例突发急性左心衰后死亡,1例复发心绞痛和1例发生亚急性支架内血栓。结论：DES应用于STEMI具有较好的安全性,其术后MAACE发生率较BMS低。     

Vascular events in healthy older women receiving calcium supplementation: randomised controlled trial

Objective To determine the effect of calcium supplementation on myocardial infarction, stroke, and sudden death in healthy postmenopausal women.Design Randomised, placebo controlled trial.Setting Academic medical centre in an urban setting in New Zealand.Participants 1471 postmenopausal women (mean age 74): 732 were randomised to calcium supplementation and 739 to placebo.Main outcome measures Adverse cardiovascular events over five years: death, sudden death, myocardial infarction, angina, other chest pain, stroke, transient ischaemic attack, and a composite end point of myocardial infarction, stroke, or sudden death. Results Myocardial infarction was more commonly reported in the calcium group than in the placebo group (45 events in 31 women v 19 events in 14 women, P=0.01). The composite end point of myocardial infarction, stroke, or sudden death was also more common in the calcium group (101 events in 69 women v 54 events in 42 women, P=0.008). After adjudication myocardial infarction remained more common in the calcium group (24 events in 21 women v 10 events in 10 women, relative risk 2.12, 95% confidence interval 1.01 to 4.47). For the composite end point 61 events were verified in 51 women in the calcium group and 36 events in 35 women in the placebo group (relative risk 1.47, 0.97 to 2.23). When unreported events were added from the national database of hospital admissions in New Zealand the relative risk of myocardial infarction was 1.49 (0.86 to 2.57) and that of the composite end point was 1.21 (0.84 to 1.74). The respective rate ratios were 1.67 (95% confidence intervals 0.98 to 2.87) and 1.43 (1.01 to 2.04); event rates: placebo 16.3/1000 person years, calcium 23.3/1000 person years. For stroke (including unreported events) the relative risk was 1.37 (0.83 to 2.28) and the rate ratio was 1.45 (0.88 to 2.49).Conclusion Calcium supplementation in healthy postmenopausal women is associated with upward trends in cardiovascular event rates. This potentially detrimental effect should be balanced against the likely benefits of calcium on bone.Trial registration Australian Clinical Trials Registry ACTRN 012605000242628.     

Follow-up of emergency ambulance calls in Nottingham: implications for coronary ambulance servie.

Information about patients in ambulance service records has been linked to that in the patients'' hospital records in an attempt to make the most efficient use of a special ambulance service for patients suspected of having heart attacks. During one week 248 emergency (999) calls for an ambulance were made by the public in the city of Nottingham. The quality of information given to the ambulance centre was poor, and all four patients eventually found to have had a myocardial infarction were described as having collapsed. A further study of patients who were also described as having collapsed has led to a system which allows an ambulance controller to send a "coronary ambulance" only in answer to those emergency calls where there is a reasonable possibility that the patient has had a heart attack.     

Ozone concentration in the ground atmosphere and morbidity during extreme heat in the summer of 2010

Dependence of the population morbidity on the ground-level ozone concentration in the summer of 2010 was studied in a city with low urbanization (Vyatskie Polyany, Kirov oblast) and in Moscow. At a high air temperature and low ozone concentration, the population morbidity was not associated with these parameters in Vyatskie Polyany. When the average daily ground-level ozone concentration exceeded 60 μg/m³ for 13 successive days, the correlation coefficient between ozone concentration and the number of ambulance calls was statistically significant, r = 0.62. Heavy smoke from forest fires reduced ozone concentration, and the number of emergency calls did not increase. In Moscow, the incidence of respiratory diseases and population mortality were growing up at high ozone concentrations.     

负荷量阿托伐他汀对稳定型冠心病患者非心脏手术围手术期保护作用的研究

目的:探讨负荷量阿托伐他汀对稳定型冠心病患者非心脏的择期外科手术围手术期主要不良心脏事件的保护作用。方法:将拟行非心脏外科手术的60名稳定型冠心病患者随机分为负荷量阿托伐他汀组(n=30)和对照组(n=30),其中负荷量阿托伐他汀治疗组在术前12小时给予阿托伐他汀80 mg顿服,术前2小时阿托伐他汀40 mg顿服,且每晚服用阿托伐他汀40 mg,对照组术前每晚服用阿托伐他汀20 mg,而后进行非心脏的外科手术(主要病种为慢性胆囊结石胆囊炎、慢性阑尾炎、消化性溃疡、疝气),术后负荷量组给予每晚服用阿托伐他汀40 mg,对照组每晚服用阿托伐他汀20 mg。比较两组围手术期主要不良心脏事件(包括心脏性猝死,急性心肌梗死,非计划性血运重建)的发生情况。结果:对照组出现1例急性前壁ST段抬高型心肌梗死并行急诊前降支介入再灌注治疗和7例无症状型心肌梗死,负荷量阿托伐他汀组出现1例无症状型心肌梗死,围手术期心肌梗死发生率较对照组明显降低(P0.05)。结论:负荷量阿托伐他汀可显著降低稳定型冠心病患者非心脏的择期外科手术围手术期主要不良心脏事件如心肌梗死,特别是无症状型心肌梗死的发生率,但该结果尚需大样本多中心随机对照临床试验进一步证实。     

Seasonality and the sudden infant death syndrome during 1987-9 and 1991-3 in Australia and Britain.

OBJECTIVE--To determine whether seasonality of the sudden infant death syndrome persists now that rates have fallen, mostly after widespread adoption of the "face upwards" sleeping position. DESIGN--Monthly data on the sudden infant death syndrome during 1987-9 were compared for seasonality with those of 1991-3; rates were studied as deaths per 1000 live births. SETTING--Australia and Britain (England, Wales, and Scotland). SUBJECTS--Infants under 1 year dying of the syndrome (2401 for Australia and 6630 for Britain). MAIN OUTCOME MEASURE--Extent of seasonal variation (amplitude) was established by cosinor analysis; amplitudes for the earlier and later years were compared. RESULTS--The rate fell in every month, and, though it did so relatively more in winter than summer, seasonality remained a distinctive feature. In the comparison of amplitudes the ratio between the earlier and later years was 1.4 in both Australia and Britain. Some differences between the hemispheres were noted. CONCLUSIONS--Seasonality of the sudden infant death syndrome remains to be explained and continues to be an important aetiological lead. Studies from other countries are needed.     

Experimental and epidemiological estimation of seasonal and climato-geographical features of non-specific resistance of the organism to influenza

One and the same series of live influenza vaccine from the strains B/Dushanbe/66 and B/Leningrad/67 or A2/Moscow/21/65 administered intranasally to non-immune persons in Leningrad and 'krasnodar in winter caused an increase in body temperature in 6.7-8% of vaccinated subjects, but in summer in 0.8%. In the transitional seasons of the year (in May and in October), 6.3-16.8% of reactions were observed in Murmansk and 0.1% in Krasnodar. An increase in antibodies in the vaccinated in Leningrad and Arkhangelsk in winter was observed 1.5 times more frequently than in summer. In Krasnodar, seroconversion occurred in only 5.7% in May and october, but in 31.3% in January; in Murmansk in 41.2-48% in May and in 75.6-78.8% in October. The seasonal as well as latitudinal and climatic differences in reactogenicity and antigenic activity of the vaccine can be explained by seasonal oscillations in non-specific resistance of people of influenza viruses. The importance of this factor in the mechanism of seasonal occurrence of influenza is discussed.     

The association between phenomena on the Sun, geomagnetic activity, meteorological variables, and cardiovascular characteristic of patients with myocardial infarction

It has been found that solar and geomagnetic activity affects the cardiovascular system. Some evidence has been reported on the increase in the rate of myocardial infarction, stroke and myocardial infarction related deaths during geomagnetic storms. We investigated the association between cardiovascular characteristics of patients, admitted for myocardial infarction with ST elevation (STEMI), and geomagnetic activity (GMA), solar proton events (SPE), solar flares, and meteorological variables during admission. The data of 1,979 patients hospitalized at the Hospital of Lithuanian University of Health Sciences (Kaunas) were analyzed. We evaluated the association between environmental variables and patient’s characteristics by multivariate logistic regression, controlling patient’s gender and age. Two days after geomagnetic storms the risk of STEMI was over 1.5 times increased in patients who had a medical history of myocardial infarction, stable angina, renal or pulmonary diseases. The dose–response association between GMA level and STEMI risk for patients with renal diseases in history was observed. Two days after SPE the risk of STEMI in patients with stable angina in anamnesis was increased over 1.5 times, adjusting by GMA level. The SPE were associated with an increase of risk for patients with renal diseases in history. This study confirms the strongest effect of phenomena in the Sun in high risk patients.     

GEOMAGNETIC ACTIVITY AND LIFE. I. EMERGENCY VISITS IN AN ORTHOPAEDIC CLINIC

We have analysed the daily number of emergency calls in an orthopaedic clinic for the period 1995–1999 and the corresponding index, Ap, of daily global geomagnetic activity (GMA). We found that both kinds of annual time series represent fractal dynamics as revealed by a Fast Fourier Transform of the series. The time series showed a seasonal, wavelike pattern. The minimum and maximum values of these waves revealed, to a first approximation, a negative correlation between Ap and emergency calls. A change in the average geomagnetic activity from one season to another can be accompanied by up to about a 16% effect on the average number of emergency calls. This suggests that the human organism continuously accumulates small or unnoticeable effects of geomagnetic activity, and the effect is only seen when examined over long periods of time of the order of seasons.     

Seasonality of occurrence and recruitment of Arctic marine benthic invertebrate larvae in relation to environmental variables

The Arctic system is one of the regions most influenced by ongoing global climate change, but there are still critical gaps in our knowledge regarding a substantial number of biological processes. This is especially true for processes taking place during the Arctic winter but also for seasonal processes, such as the dynamics of intra-annual meroplankton occurrence. Here, we report on a 1-year study of meroplankton seasonal variability from a fjordic system in the Arctic Archipelago of Svalbard. The study combines an examination of phytoplankton, zooplankton, and hard bottom benthic settlement with measurements of environmental parameters (e.g., water temperature, particulate organic matter, and dissolved organic carbon). Samples were taken on a bi-weekly or monthly basis, and a total of 11 taxa representing six phyla of meroplankton were recorded over a 1-year period from January to December 2007. The occurrence of benthic larvae varied between the seasons, reaching a maximum in both abundance and taxon richness in late spring through early summer. Meroplanktonic larvae were absent in winter. However, settlement of benthic organisms was also recorded during the winter months (February and March), which indicates individual trade-offs related to timing of reproduction and competition. In addition, it suggests that these larvae are not relying on higher summer nutrient concentrations, but instead are dependent on alternative food sources. In parallel with meroplankton abundance, all other measured parameters, both biological (e.g., phyto- and zooplankton abundance and diversity) and physical (e.g., particulate organic matter), exhibited seasonal variability with peaks in the warmer months of the year.     

The influence of meteorological and geomagnetic factors on acute myocardial infarction and brain stroke in Moscow,Russia

Evidence of the impact of air temperature and pressure on cardiovascular morbidity is still quite limited and controversial, and even less is known about the potential influence of geomagnetic activity. The objective of this study was to assess impacts of air temperature, barometric pressure and geomagnetic activity on hospitalizations with myocardial infarctions and brain strokes. We studied 2,833 myocardial infarctions and 1,096 brain strokes registered in two Moscow hospitals between 1992 and 2005. Daily event rates were linked with meteorological and geomagnetic conditions, using generalized linear model with controls for day of the week, seasonal and long-term trends. The number of myocardial infarctions decreased with temperature, displayed a U-shaped relationship with pressure and variations in pressure, and increased with geomagnetic activity. The number of strokes increased with temperature, daily temperature range and geomagnetic activity. Detrimental effects on strokes of low pressure and falling pressure were observed. Relative risks of infarctions and strokes during geomagnetic storms were 1.29 (95 % CI 1.19–1.40) and 1.25 (1.10–1.42), respectively. The number of strokes doubled during cold spells. The influence of barometric pressure on hospitalizations was relatively greater than the influence of geomagnetic activity, and the influence of temperature was greater than the influence of pressure. Brain strokes were more sensitive to inclement weather than myocardial infarctions. This paper provides quantitative estimates of the expected increases in hospital admissions on the worst days and can help to develop preventive health plans for cardiovascular diseases.     

Seasonality and causes of black grouse (Lyrurus tetrix,Galliformes, Tetraonidae) death in Western Russia according to count of remains

Black grouse (Lyrurus tetrix) death in north and middle zones of the Russian plain were studied in 1981–2013 according to counts of the remains of perished individuals. The average annual death of birds older than 1.5–2 months is estimated as 2.0–2.5 birds/km². Its maximum falls into spring or winter-spring season and minimum into summer. Predation is main cause of death; all other reasons (unusual weather, hunting, no established circumstances) determine only one-quarter of total loss. Raptors cause maximal death of black grouse in northern regions. No significant differences between death of males and females were detected, but seasonal patterns of their death is not the same, and factors that determine their act differently. The female losses as a result of activity of all predators are distributed relatively uniformly by seasons; male death is higher in spring than in other times of year. The dynamics of male and female removal by only raptors is similar: maximum in spring, decrease in summer, and drop to minimum in autumn and winter. Seasonal distribution of losses due to activity of carnivorous beasts is uneven; male death is higher in transitional seasons (as compared with winter and summer), and female losses are maximal in winter and minimal in spring-summer period.     

Sudden death in epileptic rats exposed to nocturnal magnetic fields that simulate the shape and the intensity of sudden changes in geomagnetic activity: an experiment in response to Schnabel, Beblo and May

To test the hypothesis that sudden unexplained death (SUD) in some epileptic patients is related to geomagnetic activity we exposed rats in which limbic epilepsy had been induced to experimentally produced magnetic fields designed to simulate sudden storm commencements (SSCs). Prior studies with rats had shown that sudden death in groups of rats in which epilepsy had been induced months earlier was associated with the occurrence of SSCs and increased geomagnetic activity during the previous night. Schnabel et al. [(2000) Neurology 54:903–908) found no relationship between SUD in human patients and geomagnetic activity. A total of 96 rats were exposed to either 500, 50, 10–40 nT or sham (less than 10 nT) magnetic fields for 6 min every hour between midnight and 0800 hours (local time) for three successive nights. The shape of the complex, amplitude-modulated magnetic fields simulated the shape and structure of an average SSC. The rats were then seized with lithium and pilocarpine and the mortality was monitored. Whereas 10% of the rats that had been exposed to the sham field died within 24 h, 60% of the rats that had been exposed to the experimental magnetic fields simulating natural geomagnetic activity died (P<.001) during this period. These results suggest that correlational analyses between SUD in epileptic patients and increased geomagnetic activity can be simulated experimentally in epileptic rats and that potential mechanisms might be testable directly.     

Metabolic rate and food availability of the Antarctic amphipod <Emphasis Type="Italic">Gondogeneia antarctica</Emphasis> (Chevreux 1906): seasonal variation in allometric scaling and temperature dependence

Among the few existing works on seasonal variation in metabolic rate of polar species, most have been conducted during summer due to logistic constraints and have been focused on species that cease feeding during winter. In this work, we present the first extensive data set on the seasonal variation in metabolic rate of G. antarctica, an abundant amphipod that feeds throughout the year, and its relationship with body size, potential food availability and temperature. We measured the resting metabolic rate (RMR) of groups of individuals during 6 months from late summer through winter at 4 experimental temperatures and for a wide range of body size. RMR had a negative allometric scaling with body size and showed a tendency to increase with temperature as expected. However, temperature and body size effects on RMR showed a significant temporal variation, and an increase in temperature decreased scaling exponents. RMR at the mean seawater temperature throughout the study showed a strong seasonal variation following food availability: RMR decreased from the end of summer through winter, coinciding with a reduction in microphytobenthos stock, but recovered summer values in August, when an epontic algae boom occurred. The seasonal factorial aerobic scope (×2.37) is lower than benthic Antarctic invertebrates that cease feeding during winter, in agreement with what is expected based on theoretical grounds. Results suggest that seasonal variation of RMR would allow G. antarctica to achieve a high efficiency in energy utilization, while maintaining the ability to exploit sudden changes in food supply.     

New aspects of ICD therapy: from rhythm therapy to complex cardiac monitoring. Development of an implantable, ICD-assisted, intrathoracic 6-channel ECG for continuous monitoring of high infarct risk patients]

Implantable defibrillator systems (ICD) are therapy of choice for the treatment of life-threatening ventricular arrhythmias and in prevention of sudden cardiac death. In more than 80% of patients who receive an ICD, the underlying cardiac disease is a coronary heart disease. Since arrhythmogenic sudden cardiac death can be reliably prevented in these patients by the use of ICD technology, the cardiac prognosis for these patients is determined by the occurrence of myocardial ischemia and myocardial infarction, as well as from the heart failure which develops in consequence. An intrathoracic 6-channel ECG comparable to the standard surface ECG can be reconstructed by further technical development of the electrode configurations currently present in ICD systems. The importance of this development in early diagnosis of myocardial ischemias and myocardial infarction can hardly be adequately estimated at the moment. The chronic consequences of myocardial infarction can be completely prevented or at least greatly reduced by means of such diagnostics and inclusion of immediate initiation of effective, appropriate early therapeutic measures before more serious symptoms even occur. In the development and pilot studies thus far, it has been found that the intrathoracic 6-channel ECG which can be generated in the ICD is capable of reliably recognizing acute myocardial ischemia, irrespective of localization or extent earlier and better than the standard surface ECG. Continuous preventive ischemia monitoring using the implanted ICD thus appears possible in patients at risk of infarction.     

Hemostatic triggers of myocardial infarction

The occurrence of acute ischemia in the coronary circulation, leading to myocardial infarction and sudden cardiac death and numerous other thromboembolic events in different areas of the body, follows a circadian periodic pattern. This pattern is characterized by a major peak in the morning. Numerous circadian rhythms in different compartments of the hemostatic system contribute to this characteristic pattern. The temporal coincidence of vascular rhythms favoring impairment of the coronary circulation, with a morning increase in the activity of platelets in response to stimulation with a hypercoagulable state and a circadian minimum in fibrinolysis, leads to the increased incidence of thromboembolic events at that circadian stage. Direct circadian clock-dependence has been shown for some rhythms, e.g. in fibrinolysis, and circadian rhythm disturbances may favor coronary artery pathology. The circadian transient risk state for myocardial infarctions and other thromboembolic events during the morning hours in diurnally active subjects has to be recognized and may be amenable to possible prevention. If an event has occurred, some of the hemostatic rhythms operative in this condition may also affect treatment.     

Value of thallium-201 imaging in detecting adverse cardiac events after myocardial infarction and thrombolysis: a follow up of 100 consecutive patients.

OBJECTIVE: To determine the prognostic role of thallium-201 imaging compared with that of exercise electrocardiography in patients with acute myocardial infarction treated by thrombolysis. DESIGN: Patients who remained free of adverse cardiac events six weeks after myocardial infarction had stress and rest 201TI imaging and exercise electrocardiography and were followed up for 8-32 months. Adverse cardiac events (death, reinfarction, unstable angina, and congestive heart failure) were documented. SETTING: Large district general hospital, Middlesex. SUBJECTS: 100 consecutive male and female patients who were stable six weeks after thrombolysis for myocardial infarction. MAIN OUTCOME MEASURES: Prediction of occurrence of adverse cardiac events after myocardial infarction by exercise cardiography and 201TI myocardial perfusion imaging. RESULTS: Reversible ischaemia on 201TI imaging predicted adverse cardiac events in 33 out of 37 patients with such events during follow up (hazard ratio 8.1 (95% confidence interval 2.7 to 23.8), P < 0.001). Exercise electrocardiography showed reversible ischaemia in 33 patients, of whom 13 had subsequent events, and failed to predict events in 24 patients (hazard ratio 1.1 (0.56 to 2.2), P = 0.8). CONCLUSION: 201TI imaging is a sensitive predictor of subsequent adverse cardiac events in patients who have received thrombolysis after acute myocardial infarction, whereas exercise electrocardiography fails to predict outcome.     

Underwater acoustic behavior of bearded seals (Erignathus barbatus) in the northeastern Chukchi Sea, 2007–2010

Bearded seal (Erignathus barbatus) calls were recorded using autonomous passive acoustic recorders deployed in the northeastern Chukchi Sea between October 2007 and October 2010. Continuous acoustic data were acquired during summer (August to mid‐October), and overwinter data (mid‐October through July) were acquired on a duty cycle of 40/48 min every 4 h. We investigated the spatio‐temporal distribution and acoustic behavior of vocalizing bearded seals in this multiyear data set. Peaks in calling occurred in spring, coinciding with the mating period, and calls stopped abruptly in late June/early July. Fewer calls were detected in summer, and the vocal presence of seals increased with the formation of pack ice in winter. Vocal activity was higher at night than during the day, with a peak around 0400 (AKST). Monthly patterns in proportional use of each call type and call duration were examined for the first time. The proportion and duration of AL1(T) and AL2(T) call types increased during the mating period, suggesting that males advertise their breeding condition by producing those specific longer trills. The observed seasonal and diel trends were consistent between years. These results improve our understanding of occurrence and acoustic behavior of bearded seals across the northeastern Chukchi Sea.