Background and Purpose—Acute myocardial infarction and sudden death display a circadian rhythm, with a higher risk between 6 am and noon. Some reports suggest that stroke does not follow such a circadian variation and that hemorrhagic stroke occurs more often during the evening. Methods—A meta-analysis of 31 publications reporting the circadian timing of 11 816 strokes was performed, subdividing (when possible) by the type of stroke, according to the time of onset of symptoms. When precise timing was not given, strokes were distributed evenly (that is, biasing toward the null hypothesis of lack of circadian variation). Results—All subtypes of strokes displayed a significant (P<0.001) circadian variation in time of onset, whether divided into 3-, 4-, or 6-hour time periods. There was a 49% increase (95% confidence interval, 44% to 55%) in stroke of all types between 6 am and noon (compared with expectations if no circadian variation was present), which is a 79% (95% confidence interval, 72% to 87%) increas...

Circadian Variation in the Timing of Stroke Onset A Meta-analysis

Background— Inflammatory processes have fundamental roles in stroke in both the etiology of ischemic cerebrovascular disease and the pathophysiology of cerebral ischemia. We summarize clinical data on infection and inflammation as risk or trigger factors for human stroke and investigate current evidence for the hypothesis of a functional interrelation between traditional risk factors, genetic predisposition, and infection/inflammation in stroke pathogenesis. Summary of Review— Several traditional vascular risk factors are associated with proinflammatory alterations, including leukocyte activation, and predispose cerebral vasculature to thrombogenesis on inflammatory stimulation. Furthermore, accumulation of inflammatory cells, mainly monocytes/macrophages, within the vascular wall starts early during atherogenesis. During later disease stages, their activation can lead to plaque rupture and thrombus formation, increasing stroke risk. Inflammatory markers (eg, leukocytes, fibrinogen, C-reactive protein) ar...

Inflammation and Infections as Risk Factors for Ischemic Stroke

The last 2 decades have seen major advances in understanding of the mechanism of onset and treatment of acute coronary syndromes. It has become accepted that acute myocardial infarction (MI), sudden cardiac death, and stroke can be triggered by stressors such as heavy physical exertion and severe emotional stress; the clinical implications that can be derived from the findings of triggering remain uncertain, however.

The triggering studies were stimulated by observations of a circadian variation and morning peak in MI, sudden cardiac death, and stroke that indicated that events did not occur randomly.1 In a 1989 review in Circulation ,1 we stated that although the primary value of recognizing the circadian variation of acute coronary events was the emphasis that could be placed on pharmacological protection during the morning hours, the main significance was the support it provided for the broader concept that the onset of coronary thrombosis at any time of the day is frequently triggered by activities of the patient.

The aim of the present review is to update current knowledge about triggering of acute cardiovascular disease (CVD), place it in the context of advances in understanding of the mechanisms of onset, and suggest a 5-faceted strategy to protect against the pathophysiological effects of triggering. The rationale for such a strategy is discussed, with areas for further research highlighted.

The treatment of hyperlipidemia and hypertension illustrates long-term risk factor management, in which an individual may take a daily lipid-lowering or antihypertensive agent for several years to reduce the risk of MI. Although the relative risk reduction with treatment may be 30%, the absolute risk reduction varies considerably, depending on the overall risk profile of a particular individual. For instance, in a moderately high-risk person with a 10% to 15% 5-year CVD event rate, a 30% risk …

Triggering of Acute Cardiovascular Disease and Potential Preventive Strategies

http://www.airguardmedical.com/html/content/J%20Am%20Coll%20Cardiol_Sheth_1999.pdf

Increased winter mortality from acute myocardial infarction and stroke: the effect of age

Raynaud’s phenomenon (RP) represents the most frequent clinical aspect of cardio/microvascular involvement and is a key feature of several autoimmune rheumatic diseases. Moreover, RP is associated in a statistically significant manner with many coronary diseases. In normal conditions or in primary RP (excluding during the cold-exposure test), the normal nailfold capillaroscopic pattern shows a regular disposition of the capillary loops along with the nailbed. On the contrary, in subjects suffering from secondary RP, one or more alterations of the capillaroscopic findings should alert the physician of the possibility of a connective tissue disease not yet detected. Nailfold capillaroscopy (NV) represents the best method to analyse microvascular abnormalities in autoimmune rheumatic diseases. Architectural disorganization, giant capillaries, haemorrhages, loss of capillaries, angiogenesis and avascular areas characterize >95% of patients with overt scleroderma (SSc). The term ‘SSc pattern’ includes, all together, these sequential capillaroscopic changes typical to the microvascular involvement in SSc. The capillaroscopic aspects observed in dermatomyositis and in the undifferentiated connective tissue disease are generally reported as ‘SSc-like pattern’. Effectively, and early in the disease, the peripheral microangiopathy may be well recognized and studied by nailfold capillaroscopy, or better with nailfold video capillaroscopy (NVC). The early differential diagnosis between primary and secondary RP is the best advantage NVC may offer. In addition, interesting capillaroscopic changes have been observed in systemic lupus erythematosus, anti-phospholipid syndrome and Sjogren’s syndrome. Further epidemiological and clinical studies are needed to better standardize the NCV patterns. In future, the evaluation of nailfold capillaroscopy in autoimmune rheumatic diseases might represent a tool for the prediction of microvascular heart involvement by considering the systemic microvascular derangement at the capillary nailfold.

Nailfold capillaroscopy is useful for the diagnosis and follow-up of autoimmune rheumatic diseases. A future tool for the analysis of microvascular heart involvement?

Background and Purpose Several studies have shown stroke onset to vary by season, day of the week, and time of day. These temporal patterns, which may provide insights into pathogenesis, were found mainly in clinical series, which can be subject to selection bias. To obtain a less distorted picture of stroke onset, we examined the month and season, day of the week, time, and place stroke occurred in a community-based cohort. Methods Over a 40-year period of surveillance of the Framingham Study cohort of 5070 people aged 30 to 62 years and free of stroke and cardiovascular disease at entry, 637 completed initial strokes occurred. Month, season, day of the week, time of day, and place of occurrence of stroke were ascertained systematically and related prospectively to stroke incidence, subtype, and gender. Results Winter was the peak season for cerebral embolic strokes. Significantly more stroke events occurred on Mondays than any other day, particularly for working men. For intracerebral hemorrhages, a thi...

Temporal Patterns of Stroke Onset The Framingham Study

The prevalence and predisposing conditions for primary and secondary Raynaud's phenomenon (RP) were examined in The Framingham Study based on 16 years of follow-up of a cohort of 4182 men and women. The association with atypical chest pain and migraine headache was also investigated. Over the 16 years of follow-up there were 130 men and 171 women who developed primary RP. The prevalence in women (9.6%) was somewhat higher than in men (8.1%) and 81.4% of the RP was primary. Secondary RP was equally prevalent in men (18.6%) and women (19.7%). The most common causes of secondary RP were beta-blocker use (34.2%), carpal tunnel syndrome (10.5%) and rheumatoid arthritis (7.2%). Primary RP cases differed from noncases by having lower systolic blood pressure (p < or = 0.001) and diastolic blood pressure (p < 0.0001), and more coronary disease (p = 0.009), smoking (p < or = 0.01) and higher blood sugars (p < or = 0.009). Atypical chest pain was present more often than noted previously in The Framingham Study general population survey, and was equally prevalent in primary and secondary RP and in the two sexes. Associated migraine was more prevalent in women (14.4%) than men (5.0%). Vibrating tool use with associated RP occurred in 14.6%.

https://vmj.sagepub.com/content/2/4/296.full.pdf

Jacqueline M. McGuirk

Papers

Temporal Patterns of Stroke Onset The Framingham Study

The Occurrence of Raynaud's Phenomenon in a General Population: The Framingham Study