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Query: UMLS:C0038454 (stroke)
 147,016 document(s) hit in 31,850,051 MEDLINE articles (0.00 seconds)

Left ventricular hypertrophy is associated with an increased cardiovascular mortality in hypertension. A potential role of ventricular arrhythmias is debated but not yet determined. The purpose of this study was to evaluate whether the presence of arrhythmias would ascribe any additional risk to cardiovascular mortality beyond that related to the presence of left ventricular hypertrophy. From November 1988 to February 1991, 40 mild to severe hypertensive patients (mean SBP, DBP 183/117 mm Hg) were submitted to clinical, echocardiographic and electrocardiographic evaluations complemented by 24-h Holter monitoring and then followed until November 1996. The Kaplan-Meier method supplemented by the Cox multiple regression model were performed to identify the variable(s) associated with fatal cardiovascular outcome. Twelve cardiovascular fatalities occurred as a consequence of sudden death (n = 4), stroke (n = 4), heart failure (n = 2) and myocardial infarction (n = 2). In comparison with patients who survived, those dying from cardiovascular causes had a greater percentage of electrocardiographic left ventricular hypertrophy (83 vs 36%, P = 0. 0037) and couplets of ventricular ectopic beats (58 vs 18%, P = 0. 0467). In addition, they showed larger left ventricular diastolic diameter (60 +/- 10 vs 53 +/- 8 mm), mass index (248 +/- 67 vs 154 +/- 57 g/m2) and posterior wall thickness (12 +/- 2 vs 10 +/- 2 mm), as well as shorter left ventricular fractional shortening (0.23 +/- 0.8 vs 0.32 +/- 0.9). Univariate analysis showed that electrocardiographic left ventricular hypertrophy and strain, mass index, end-systolic wall stress, fractional shortening and the presence of couplets were significantly related to cardiovascular mortality. However, only mass index was shown to be independently associated with cardiovascular death. In conclusion, left ventricular hypertrophy predicts cardiovascular outcome, regardless of the presence of other signs of cardiac damage, including ventricular arrhythmia.
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PMID:Left ventricular hypertrophy predicts outcome of hypertension regardless of the type of ventricular arrhythmia present. 1048 71

A disproportionate increase in SBP over DBP has been recognized for many years as a frequent accompaniment of aging. Initially this was considered to be benign, risk free and potentially dangerous to treat. Study over the years has shown that it is not benign and that antihypertensive therapy can reduce the risks of stroke, myocardial infarction, congestive heart failure and cardiovascular death. Currently, the drugs most widely recommended for this purpose are the thiazide diuretics, long acting dihydropiridine calcium channel antagonists, ACE inhibitors, and beta blocking agents. There may be a special place for nitrates, since these agents are very effective in increasing arterial distensibility--a primary abnormality of the disorder--but a formal study of their effectiveness has not been done. Concern about diastolic hypotension during therapy suggests that treatment to lower the blood pressure in this disorder should be carried out gradually with the aim of reducing the SBP toward normal while avoiding diastolic hypotension.
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PMID:Clinical studies and therapeutic trials in systolic hypertension. 1052 66

Oxidative stress has been reported to be involved in not only cardiovascular diseases but in hypertension, which is a major risk for cardiovascular diseases. Urinary 8-hydroxy-2'-deoxyguanosine (8-OHdG) has been recognized as a sensitive biomarker of oxidative DNA damage and also of oxidative stress. In the present study, we assessed the oxidative stress in human subjects with hypertension and in hypertensive rats. In stroke-prone spontaneously hypertensive rats at the age of 14 weeks, the excretion of urinary 8-OHdG was significantly (p < 0.05) increased compared with that in age-matched normotensive Wistar-Kyoto rats. Next, we investigated the relationship between oxidative DNA damage and cardiovascular risk factors among Tanzanians aged 46-58 years in a population study carried out in 1998 in at Dar es Salaam, Tanzania, according to the WHO-CARDIAC Study Protocol. Sixty subjects (male/female, 28/32) were selected by SPSS Base 8.0 from those who completed a 24-h urine collection. The 24-h urinary 8-OHdG of the hypertensive subjects (SBP > or =140 mmHg and/or DBP > or =90 mmHg) was significantly (p < 0.05) higher than that of the normotensive subjects (SBP <140 mmHg and DBP <90 mmHg) after adjusting for age and gender (Hypertensives: 17.31 +/- 2.0 ng/mg creatinine, n=38; Normotensives: 10.10 +/- 2.64 ng/mg creatinine, n=22). Oxidative stress was thought to be involved in hypertensive subjects and in hypertensive rats.
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PMID:Assessment of in vivo oxidative stress in hypertensive rats and hypertensive subjects in Tanzania, Africa. 1082 Nov 40

The Study on COgnition and Prognosis in the Elderly (SCOPE) is a multi-centre, prospective, randomized, double-blind, parallel-group study. The primary objective of SCOPE is to assess the effect of the angiotensin II type 1 (AT1) receptor blocker, candesartan cilexetil 8-16 mg once daily, on major cardiovascular events in elderly patients (70-89 years of age) with mild hypertension (DBP 90-99 and/or SBP 160-179 mmHg). The secondary objectives of the study are to test the hypothesis that antihypertensive therapy can prevent cognitive decline (as measured by the Mini Mental State Examination, MMSE) and dementia, and to assess the effect of therapy on total mortality, myocardial infarction (MI), stroke, renal function, and hospitalization. A total of 4964 patients from 15 participating countries were recruited during the randomization phase of SCOPE, exceeding the target population of 4000. The mean age of the patients at enrolment was 76 years, the ratio of male to female patients was approximately 1:2, and 52% of patients were already being treated with an antihypertensive agent at enrolment. The majority of patients (88%) were educated to at least primary school level. At randomization, mean sitting blood pressure values were SBP 166 mmHg and DBP 90 mmHg, and the mean MMSE score was 28. Previous cardiovascular disease in the study population included myocardial infarction (4%), stroke (4%) and atrial fibrillation (4%). Men, more often than women, had a history of previous MI, stroke and atrial fibrillation. A greater percentage of men were smokers (13% vs 6% in women) and had attended university (11% vs 3% of women). Of the randomized patients, 21% were 80 years of age. In this age group smoking was less common (4% vs 10% for 70-79-year-olds) and fewer had attended university (4% vs 7% for 70-79-year-olds). The incidence of MI was similar in both age groups. However, stroke and atrial fibrillation had occurred approximately twice as frequently in the older patients. The patients' mean age at baseline was similar in the participating countries, and most countries showed the approximate 1:2 ratio for male to female patients. There was also little inter-country variation in terms of mean SBP, DBP or MMSE score. However, there was considerable regional variation in the percentage of patients on therapy prior to enrolment.
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PMID:Study on COgnition and Prognosis in the Elderly (SCOPE): baseline characteristics. 1085 39

This epidemiological study was carried out as a 3-year follow-up project to assess the incidence of transient ischemic attacks (TIAs) and strokes; 8,846 treated hypertensive patients (mean BP, 149/84 mm Hg) aged 65 years or over (mean age, 73.7 +/- 6.3 years), devoid of symptoms of dementia and with documented vascular risk factors were recruited from January 1994 to August 1995, by 1,598 general practitioners in connection with 36 referral university neurology units throughout metropolitan France. Among these patients, 506 (5.7%) had at least one cerebrovascular event during the follow-up period: 309 (3.5%) experienced one or more isolated TIAs, and 197 (2.2%) had a stroke with or without a preceding TIA. A total of 510 TIAs were reported. The stroke subtypes were ischemia, hemorrhage, and unclassified in 70, 16, and 15% of the cases, respectively. The estimated annual stroke incidence was 7.42 per thousand. Of the 197 patients who developed strokes, 51 (26%) died. This case-fatality rate should be compared with the 4.5% mortality rate observed in the whole population during the study period. The 3 subgroups (with isolated TIAs, strokes, or no events during the study) were found to differ regarding age, sedentary lifestyle, past history of cardiovascular events, duration of hypertension, and evidence of complicated hypertension (univariate analysis). The factors identified as predictive of a stroke (multivariate analysis) were: the patient's age; sedentary lifestyle; pulse pressure (SBP-DBP); identification of TIA at baseline, and presence of arrhythmias.
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PMID:Incidence and predictive factors of cerebrovascular events in 8,846 elderly treated hypertensive patients during a 3-year follow-up: the PRESAGE study. 1124 71

Malignant stroke-prone spontaneously hypertensive rats (M-SHRSP), separated from SHRSP, develop severe hypertension and spontaneously develop stroke at early ages. Using this model of cerebrovascular stroke, influence of stroke-onset on the autonomic nervous system was investigated. Heart rate (HR), systolic and diastolic blood pressures (SBP and DBP) and locomotive activity were monitored during development of stroke using a telemetry system. Stroke-onset was assessed by neurologic symptoms, changes in body weight, fluid intake and serum NOx level. The rat displayed a nocturnal pattern of circadian rhythms. At stroke-onset, mean HR over 24 h increased by 20 to 30 bpm and rapidly increased at post stroke, approximately 100 bpm higher than that at pre stroke. Circadian variation in HR, which was normally 50 bpm higher during night than during day, attenuated at stroke-onset, and it was blunted or reversed at post stroke. BP variation, which was approximately 7 mmHg higher at night than at day, decreased one or two days before stroke-onset and reversed at post stroke, especially in DBP. Insufficient falls in HR and BP during the day mainly accounted for the disturbed circadian variations. Variation of locomotive activity also decreased. These changes serve as reliable and accurate markers for stroke-onset in evaluation of drugs for the prevention and outcome predictions of stroke.
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PMID:Disturbance of circadian rhythm in heart rate, blood pressure and locomotive activity at the stroke-onset in malignant stroke-prone spontaneously hypertensive rats. 1128 3

We developed a mathematical model describing the interaction between the heart and the arterial system. The model was constructed and tested on basis of invasive hemodynamic data in six sheep. Data from a first group of three animals (49 cardiac cycles) were used to assess a template time-varying elastance curve for the left ventricle, while the baseline steady-state data of a second group of three animals were used to assess reference cardiac and arterial parameters in sheep. The model is fully characterized by nine parameters, which were converted into 6 dimensionless numbers using the Buckingham pi theorem. The model was then used to generate LV pressure and volume and aortic pressure and flow for 86 conditions obtained by varying parameters 50 to 200% of their reference value. Systolic (SBP) and diastolic (DBP) blood pressure and stroke volume (SV) were determined from these model-generated curves and multiple linear regression analysis yielded the following expressions: SBP = Pisovolumic [0.638 - 0.0773 Emax C + 0.0507 RC/T] (r2 = 0.89); DBP = Pisovolumic [0.438-0.0712 Emax C + 0.0655RC/T] (r2 = 0.88) and SV = LVEDV [1.265-1.040 LVEDV/(LVEDV - Vd) + 0.125 Emax C-0.0777RC/T] (r2 = 0.93) with Pisovolumic = Emax (LVEDV - Vd), Emax and Vd being the slope and intercept of the end-systolic pressure-volume relation, R and C the total peripheral resistance and compliance, LVEDV the left ventricular end-diastolic volume, and T the cardiac cycle length. These expressions were validated using data from the second group of three animals obtained during vena cava occlusion at baseline and during administration of dobutamine (61 cycles). The correlation between measured and predicted values was 0.98, 0.97 and 0.92 for SBP, DBP and SV, respectively. Compared to the measured values, SBP and DBP were, on average, underestimated by 5 and 6mmHg, respectively, and SV overestimated by 1.4 ml. We conclude that the derived expressions for blood pressure and stroke volume remain valid in the intact sheep for various hemodynamic conditions, and, taking into account their dimensionless form, may hold in other species and in humans.
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PMID:Predicting systolic and diastolic aortic blood pressure and stroke volume in the intact sheep. 1142 79

The long-acting calcium antagonist nifedipine reduces the incidence of stroke in Eastern Asia, as shown by the Shanghai Trial Of Nifedipine in the Elderly (STONE) and the Systolic Hypertension in China (Syst-China) trials. Recent trials in Japan have shown that benidipine may be more efficient than the former drug in preventing strokes in the elderly. Benidipine, commonly prescribed in Japan for a definite depressor effect, reportedly without causing remarkable fluctuations in blood pressure (BP), is investigated herein from a chronobiological viewpoint. Eighteen subjects (nine women and nine men, 39 to 87 years of age) with essential hypertension (office and ambulatory systolic, S/diastolic, D BP values above 160/95 mm Hg and 130/80 mm Hg, respectively) were enrolled in this investigation. Ambulatory BP was monitored at 30-min intervals for at least 24 h (ABPM-630, Colin Medical) before and after 4 weeks of crossover treatment with nifedipine tablets (twice daily, 20 mg/d) and benidipine (once daily, 4 mg/d, in the morning). The results indicate that: 1) benidipine and nifedipine reduce 24-h daytime (10:00-20:00) and nighttime (00:00-06:00) averages of SBP and DBP (P < 0.001); 2) the circadian double amplitude of BP is decreased after treatment with benidipine (from 28.6 to 21.1 mm Hg SBP and from 19.7 to 15.2 mm Hg DBP; P< 0.05), while the day-night difference in SBP is increased after treatment with nifedipine (18.6 vs 27.9 mm Hg, P< 0.01); and 3) the increase in the day-night difference of heart rate (HR) is significant after treatment with benidipine (13.6 vs 18.8 beats per minute, bpm; P< 0.05), but not with nifedipine. We have previously evaluated the usefulness of the circadian amplitude of BP as a prognostic tool of cardiovascular outcome, and found that an excessive circadian SBP or DBP amplitude was associated with an increased risk of vascular disease. The fact that benidipine reduces the circadian BP amplitude may be one reason for the superiority of this treatment over nifedipine in preventing an adverse outcome. A reduced heart rate variability (HRV) also predicts adverse cardiovascular outcomes in patients with overt cardiovascular disease and in hypertensive subjects. The fact that benidipine increases the day-night difference in HR may be another reason for the positive effects of this treatment.
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PMID:Impact of circadian amplitude and chronotherapy: relevance to prevention and treatment of stroke. 1177 59

To calculate the estimated relative and absolute risks for cardiovascular diseases according to alcohol consumption increase, we performed a cross-sectional study of men aged 40-79 years using the data from the National Survey of Circulatory Disorders 1990 in Japan. First, we investigated the association between alcohol intake and two types of biochemical variables: serum lipids and blood pressure, by using analysis of variance. Then, concerning the subjects aged 40-59 years, linear regression analyses between alcohol intake and these biochemical markers were done to calculate regression coefficients adjusted for confounding factors. Finally, we substituted these regression coefficients for previously reported regression coefficients in Cox proportional hazard models to calculate relative and absolute risks for coronary heart disease and stroke. Alcohol intake positively correlated to systolic and diastolic blood pressure (SBP and DBP) and high-density lipoprotein cholesterol (HDLC). However, there was no relation between alcohol intake and serum total cholesterol. Linear regression coefficients of SBP, DBP and HDLC were 2.25, 1.43, 2.70, respectively. We used two proportional hazard regression formulas of Japanese population: one for coronary disease (Circulation 89, 2533-39) and the other for stroke (NIPPON DATA80, a 14-year cohort study of randomly selected Japanese). The estimated relative risks of coronary heart disease and stroke were 0.89 and 1.06 for 1 "go" (23 g of ethanol) increment of alcohol intake. The results indicate that the mortality rates shift from 0.44 to 0.39 per 1,000 person-years for coronary heart disease and from 0.76 to 0.81 per 1,000 person-years for stroke in the representative Japanese population aged 40-59 years. The absolute risk of cardiovascular disease may be unchanged if we assume 23 g increment of ethanol intake in Japan because the risk reduction in coronary heart disease was nearly equal to the risk increment in stroke.
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PMID:[Estimated relative and absolute risk for cardiovascular disease according to alcohol consumption increase in Japanese general population]. 1182 15

In order to understand the changes of baroreflex gain due to postural changes in normal pregnancies, we measured percentage changes (% changes) in blood pressure (SBP, DBP), heart rate (HR), stroke volume (SV), cardiac output (CO), total peripheral resistance (TPR) as well as cardiac autonomic nervous function (HF as an index of parasympathetic and LF/HF as an index of sympathetic function) and compared these parameters in normal pregnancies with those found in hypertensive pregnancies, such as chronic hypertensive (CHP) and severe preeclamptic pregnancies (PE), in late pregnancy (after 32 wks). When the position was changed from supine to standing in normal and non-pregnant women, the % changes of HR, DBP, TPR and LF/HF were increased and SBP, SV, CO and HF were decreased. The % changes of these parameters, however, were gradually decreased as pregnancy progressed, especially after 20-24 wks of gestation. In hypertensive pregnancies, however, even in late pregnancy, the decreased SBP and increased TPR was still observed and the profound decrease of CO and SV and increase of TPR were characteristic in PE when compared to CHP.
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PMID:The effects of postural changes of baroreflex gain in normal and hypertensive pregnancies. 1184 66


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