Ischemic Episodes In Patients Research Articles

Results of holter monitoring in patients with coronary heart disease depending on the severity of atherosclerotic lesions of the coronary arteries

The aim – to conduct a comparative analysis of the presence, frequency and duration of episodes of myocardial ischemia and arrhythmias based on the results of Holter monitoring in patients with coronary heart disease depending on the condition of the coronary arteries.
 Materials and methods. We examined 53 patients (group I) with stable coronary heart disease (CHD) and slightly altered coronary arteries (INOCA), who were hospitalized in the period from October 2018 to February 2021 at the “City Clinical Hospital № 8” of Kharkiv City Council. Group II included 52 patients with a diagnosis of stable coronary heart disease, and according to coronary angiography (CAG) had stenosis of coronary arteries (CA) more than 50 %.
 Results. According to the results of comparative analysis, it was found that in group I there were signs of myocardial ischemia – depression of the ST segment in 62.3 % (n=33) and elevation of the ST segment in 11.3 % (n=6), compared with group II -73 % (n=38) and 5.66 % (n=3), respectively. Ventricular arrhythmias (VA) have been reported in 52 patients of group I, and in 44 patients of group II. VA 4 and 5 type according to Laun, was significantly higher in group II compared with group I (p=0.0324). The occurrence of ventricular tachycardia was recorded in 5.7 % (n=3) of patients in group I and 9.3 % (n=5) patients of group II (p=0.347). In group II, there was a tendency to more episodes of ischemia compared with group I (p=0.072). The duration of ischemia was significantly longer in group I, compared with group II (p=0.042).
 Conclusions. The results of the study did not show significant differences in the development of the number of episodes of myocardial ischemia according to Holter monitoring depending on the condition of the coronary arteries. The duration of episodes of ischemia in patients with INOCA is significantly longer than in patients with obstructive atherosclerosis. In patients with coronary heart disease with obstructive coronary arteries, ventricular arrhythmia was statistically significantly more severe according to Lown

ОСНОВНІ ХАРАКТЕРИСТИКИ ПОРУШЕНЬ РИТМУ У ПАЦІЄНТІВ З АРТЕРІАЛЬНОЮ ГІПЕРТЕНЗІЄЮ ТА ХРОНІЧНОЮ ІШЕМІЧНОЮ ХВОРОБОЮ СЕРЦЯ НА ФОНІ ГАСТРОЕЗОФАГЕАЛЬНОЇ РЕФЛЮКСНОЇ ХВОРОБИ

<p>Резюме. Мета роботи – продемонструвати вплив ГЕРБ на перебіг ІХС на прикладі аналізу кількісних і якісних характеристик порушень ритму, а також частоти і тривалості ішемічних епізодів у пацієнтів з АГ в поєднанні з хронічною ІХС на тлі ГЕРХ. З цією метою було обстежено 107 пацієнтів з АГ в поєднанні з хронічною ІХС, віком від 44 до 78 років. Середній вік пацієнтів склав 63,4±8,94 року, в тому числі 73 (68,2 %) жінок і 34 (31,8 %) чоловіків. Основною групу склало 65 пацієнтів з АГ в поєднанні з хронічною ІХС на тлі ГЕРХ і 42 пацієнти з АГ в поєднанні з хронічною ІХС без супутньої ГЕРХ, відповідно, увійшло в групу контролю. Були проведені всі необхідні загальноклінічні та інструментальні обстеження відповідно до поставлених завдань дослідження: загальноклінічне дослідження, ЕхоКГ, холтерівське моніторування ЕКГ, езофагогастродуоденоскопія. Отримані дані свідчать про значно більшу частоту порушень ритму як суправентрикулярних, так і шлуночкових, в групі пацієнтів з АГ в поєднанні з хронічною ІХС на тлі ГЕРХ. Крім того, за кількісними характеристиками порушень ритму пацієнти з супутньою ГЕРХ характеризувалися більш тяжким перебігом порушень ритму, що відображалося великою кількістю пацієнтів з аритміями більш високих градацій. Наявність супутньої ГЕРХ у пацієнтів з АГ в поєднанні з хронічною ІХС достовірно частіше асоціювалося з наявністю ФП. Частота ішемічних епізодів у пацієнтів з АГ в поєднанні з хронічною ІХС на тлі ГЕРХ була достовірно частіше в порівнянні з пацієнтами без супутньої ГЕРХ. Таким чином ГЕРБ у пацієнтів з АГ в поєднанні з хронічною ІХС є додатковим фактором, який погіршує перебіг ІХС і створює умови для підвищення загального кардіоваскулярної ризику.</p>

Impaired Cerebrovascular Reactivity Predicts Recurrent Symptoms in Patients with Carotid Artery Occlusion: A Hypercapnia BOLD fMRI Study.

A key factor in predicting recurrent ischemic episodes in patients with carotid artery occlusion is the presence of hemodynamic impairment. There is, however, no consensus on how to best assess this risk in terms of imaging modalities or thresholds used. Here we investigated whether a predefined threshold of hemispheric asymmetry in hypercapnia fMRI predicts recurrent symptoms in patients with carotid artery occlusion. We studied 23 patients (2 women) with a mean age of 67.5 ± 9 years. Patients were assessed for recurrent ischemic events until lost to follow-up, study end, death, or recurrent ischemic event. Hypercapnia fMRI was used to assess the cerebrovascular reserve and quantify the percentage signal change in GM in the MCA territory and the hemispheric asymmetry index. Kaplan-Meier survival analysis and log-rank tests were performed to assess differences between patients with normal or abnormal hemispheric indices. The median follow-up was 20 months. During this period, 8 patients experienced recurrent events, and 15 did not. The percentage signal change in GM in the MCA territory was significantly decreased in those patients with recurrent events compared with those without (2.39 ± 0.22 versus 2.70 ± 0.42, P = .032). The normal hemispheric index predicted event-free survival during follow-up (median, 20 months) for both the combined outcome (recurrent events and/or death, log-rank, P = .034) and recurrent retinal or ipsilateral ischemic events only (log-rank, P = .012). The hemispheric asymmetry index derived from hypercapnia fMRI showed hemodynamic impairment in more than half of the studied patients with carotid occlusion, and those patients showed a higher risk of recurrent ischemic symptoms.

Mitral and aortic annular calcifications and cerebrovascular ischemic episodes in patients with coronary artery disease.

Atherosclerosis is a systemic pathological process involving the whole arterial bed. Valvular calcifications are associated with cardiovascular risk factors. Significant carotid stenosis accounts for approximately 20% of cerebrovascular ischemic episodes. The aim of the study was to assess the relationship between mitral and aortic annular calcifications, increased carotid intima-media thickness (CIMT), and incidence of cerebrovascular ischemic episodes. A total of 127 patients with angiographically confirmed coronary artery disease (68 men and 59 women; aged 74 (33-87) years) were divided into 4 groups: with aortic valve calcifications (AVCs), mitral annular calcifications (MACs), both aortic valve and mitral annular calcifications (AMVCs), and no valvular calcifications (no-VCs), based on the echocardiographic assessment of the mitral and aortic valves. CIMT and the presence of atherosclerotic plaques were evaluated by carotid ultrasonography. A history of cerebrovascular ischemic episodes was obtained. The combined prevalence of mitral or aortic valve calcifications in the study population was 59% (AVCs, 55%; MACs, 24%; and AMVCs, 21%). CIMT was significantly increased in the MAC and AMVC groups (P <0.05 for MACs; P <0.01 for AMVCs). Ischemic stroke was more common in the AVC group (P <0.05), while the MAC group had a higher incidence of carotid plaques (P <0.05), transient ischemic attacks (TIA; P <0.05), and strokes (P <0.05) as compared with the no-VC group. In multivariate analysis, only MACs remained independently associated with increased CIMT. In patients with coronary artery disease, MACs are independently associated with increased CIMT but not with TIA or stroke. There is no relationship between the concomitant presence of mitral and aortic calcifications and carotid atherosclerosis.

Abstract T P364: Longitudinal Evaluation of Functional Magnetic Resonance Imaging on Working Memory in Patients after Transient Ischemic Attack

OBJECTIVE: Transient ischemic attack (TIA) can increase the risk of cognitive decline, especially in attention-executive-psychomotor functioning. However, whether TIA patients have altered patterns of brain activation during this function, and whether there is a dynamic change on cerebral activity patterns, have not been examined to date. This study is designed to using functional magnetic resonance imaging (fMRI) to investigate longitudinal changes in brain activation during a verbal working memory (VWM) task in patients with TIA. METHODS: The current study included 25 patients with first-ever TIA in right hemisphere and 25 healthy volunteers. N-Back VWM task-related fMRI were conducted one week and three months after TIA onset. The brain activity evoked by n-back task in the patients was assessed and compared with that of the controls. Significant changes in cerebral activation over time were also observed in TIA patients. RESULTS: The groups did not differ on any demographic, cognitive and task performance variables. Compared with healthy subjects, patients at one week after TIA demonstrated increased activity in bilateral inferior frontal gyrus (IFG), right dorsolateral prefrontal cortex (DLPFC), insula, inferior parietal lobe (IPL) and cerebellum during the task. However, at 3-month follow-up, the task-related brain activity in patients was clearly less recruited, and only right IFG still exhibited increased activity. Moreover, a direct comparison of fMRI data between one week and three months after TIA showed that there was increased activation in bilateral middle temporal gyrus (MTG), right DLPFC, IPL, cerebellum and left IFG in patients at one week after TIA. CONCLUSIONS: These findings support the hypotheses that the patterns of brain activity during VWM performance may change for a period of time post-TIA despite the cessation of clinical symptoms. They also provide evidence of a progressive normalization of the VWM activation pattern after transient episodes of ischemia in patients with first-ever TIA.

Mitral and aortic calcifications are associated with cerebrovascular ischemic episodes in coronary patients

Purpose: Atherosclerosis is a systemic pathological process involving the whole vascular bed. Valvular calcifications are reported to be associated with cardiovascular risk factors. Significant carotid stenosis is a cause of 5-10% of cerebrovascular ischemic episodes. We investigated whether there is a relationship between mitral or aortic calcifications, intimal carotid disease and incidence of cerebrovascular ischemic episodes. Methods: The group of 126 patients with angiographically confirmed coronary artery disease (M-68;F-58;aged 70±10.5 yrs) was divided into 4 subgroups according to the echocardiographic assessment of the mitral and aortic valve: AVC-aortic valve calcifications; MVC-mitral valve calcifications; AMVC- calcifications on both valves; no-VC- no valvular calcifications. Intima-media thickness (IMT) and carotid atherosclerotic lesions were evaluated by ultrasonography of carotid arteries and the history of cerebrovascular ischemic episodes was obtained. Excluding criteria were: atrial fibrillation, medium and severe aortic or mitral stenosis, past thromboembolic events and diagnosed trombophilia. Results: The combined prevalence of mitral or aortic valve calcification in the study population was 58% (of which AVC-77%, MVC-44% and 20%-both valves). IMT was significantly increased in AVC, MVC and AMVC groups comparing with no-VC group (p<0.05 for AVC and MVC; p<0.01 for AMVC group). As compared with no-VC group an ischemic stroke was significantly more common in the AVC group (p<0.05) while MVC were associated with carotid plaques (p<0.05), transient ischemic attack (p<0.05) and stroke (p<0.05). Conclusions: Both aortic and mitral valvular calcifications are associated with intimal carotid disease and cerebrovascular ischemic episodes in patients with coronary artery disease.

Effects of chronic testosterone administration on myocardial ischemia, lipid metabolism and insulin resistance in elderly male diabetic patients with coronary artery disease

Background The evidence of antiatherogenic and vasodilatatory effects of testosterone (T) suggest a possible role of the lack of this hormone in the development and pathophysiology of coronary artery disease (CAD). Aim of the present study was to evaluate the effects of oral administration of testosterone undecanoate during a period of three months on serum lipid levels and on the occurrence of anginal attacks and daily ischemic episodes in patients with CAD. Methods and results Eighty seven (87) diabetic male subjects (mean age: 74 ± 7 years) with proven CAD were randomized to a 12 week treatment with either T undecanoate (40 mg administered three daily) or placebo (P) in a double blind protocol. Weekly episodes of angina attacks, number of ischemic episodes daily and total ischemic burden on ambulatory ECG Holter were evaluated at baseline and at the end of the study. Serum total cholesterol and triglyceride concentrations were also measured at the same time points. Compared to P, T significantly reduced the number of anginal attacks/weeks of 34% ( p < 0.05); the silent ischemic episodes of 26% ( p < 0.05), and the total ischemic burden of 21% ( p < 0.05) on ambulatory ECG monitoring. After 12 weeks total cholesterol, plasma triglycerides and HOMA index were significantly reduced in the T group compared to P group. Conclusions Three months administration of T has beneficial effect on serum cholesterol and triglyceride levels in patients with CAD and reduces the number of anginal attacks, and ischemic episodes. These effect may be related to the metabolic and vasoactive properties of the hormone. Further studies are needed in order to assess the long term relevance of these effects.

Antianginal Actions of Beta-Adrenoceptor Antagonists

Angina pectoris is usually the first clinical sign of underlying myocardial ischemia, which results from an imbalance between oxygen supply and oxygen demand in the heart. This report describes the pharmacology of beta-adrenoceptor antagonists as it relates to the treatment of angina. The beta-adrenoceptor antagonists are widely used in long-term maintenance therapy to prevent acute ischemic episodes in patients with chronic stable angina. Beta-adrenoceptor antagonists competitively inhibit the binding of endogenous catecholamines to beta1-adrenoceptors in the heart. Their anti-ischemic effects are due primarily to a reduction in myocardial oxygen demand. By decreasing heart rate, myocardial contractility and afterload, beta-adrenoceptor antagonists reduce myocardial workload and oxygen consumption at rest as well as during periods of exertion or stress. Predictable adverse effects include bradycardia and cardiac depression, both of which are a direct result of the blockade of cardiac beta1-adrenoceptors, but adverse effects related to the central nervous system (eg, lethargy, sleep disturbances, and depression) may also be bothersome to some patients. Beta-adrenoceptor antagonists must be used cautiously in patients with diabetes mellitus, peripheral vascular disease, heart failure, and asthma or other obstructive airway diseases. Beta-adrenoceptor antagonists may be used in combination with nitrates or calcium channel blockers, which takes advantage of the diverse mechanisms of action of drugs from each pharmacologic category. Moreover, concurrent use of beta-adrenoceptor antagonists may alleviate the reflex tachycardia that sometimes occurs with other antianginal agents.

Metabolic Therapy for Patients with Diabetes Mellitus and Coronary Artery Disease

Patients with diabetes mellitus and ischemic heart disease more frequently develop heart failure and have a greater amount of myocardial ischemia, often silent, compared with patients without diabetes. Furthermore, patients with coronary artery disease (CAD) and diabetes or insulin resistance have altered myocardial metabolism and accelerated and diffuse atherogenesis with involvement of distal coronary segments that causes chronic hypoperfusion and hibernation. Therefore, in patients with diabetes and CAD, the ischemic metabolic changes are heightened by the metabolic changes in patients with diabetes. An important metabolic alteration in patients with diabetes is the increase in free fatty acid (FFA) concentrations and the increased skeletal muscle and myocardial FFA uptake and oxidation. The increased uptake and utilization of FFA and the reduced utilization of glucose as a source of energy during stress and ischemia contribute to the increased susceptibility of diabetic hearts to myocardial ischemia and to a greater decrease of myocardial performance for a given amount of ischemia compared with nondiabetic hearts. A therapeutic approach aimed at an improvement in cardiac metabolism through manipulations of the use of metabolic substrates should result in an improvement in myocardial ischemia and left ventricular (LV) function. The inhibition of FFA oxidation with trimetazidine improves cardiac metabolism at rest, increases cardiac resistance to ischemia, and therefore reduces the decrease of LV function caused by chronic hypoperfusion and repetitive episodes of myocardial ischemia in patients with and without diabetes. Thus, modulation of myocardial FFA metabolism should be the key target for metabolic interventions in patients with CAD with and without diabetes. In patients with diabetes, the effects of modulation of FFA metabolism should be even greater compared with those observed in patients without diabetes. Because of its effect on cardiac metabolism at rest and its effects on myocardial ischemia and LV function, trimetazidine should always be considered for the treatment of patients with diabetes with CAD with or without LV dysfunction.

Oxidative stress and cardiovascular injury: Part II: animal and human studies.

This review so far has considered the role of vascular cells in the generation of reactive oxygen species (ROS) and novel approaches to their detection in integrated systems such as animal models of vascular disease and humans. We now turn attention to evidence consistent with a role for ROS in models of human disease and in discrete patient populations. We also briefly comment on the outcomes of clinical trials of antioxidants. Mainly, these have been disappointing. However, it is premature to conclude that the oxidation hypothesis of disease causality has been adequately tested. Animal studies, for the most part, support a fundamental role for ROS in cardiovascular disease. Any controversy could in part reflect the use of ineffective antioxidants and the selection of models in which ROS generation is of marginal relevance to the measured outcome. Both of these issues require a quantitatively accurate measurement of drug effect (ie, antioxidant capacity) before hypotheses relating to the role of oxidant stress can be addressed rationally. These issues pertain to clinical trials also, as we will discuss. However, animal studies permit administration of much more powerful antioxidants (eg, rate constant for interaction of superoxide dismutase (SOD) with O2·− ≈1.6×109 · mol/L−1 · s−1) than is possible in humans (eg, rate constant for vitamin E ≈0.59 mol/L−1 · s−1) or, like in the case of vitamin E, doses of the antioxidant in excess of those usually applied in clinical research. ### Atherosclerosis Animal models of atherosclerosis have documented that all the constituents of the plaque produce and use ROS. Lesion formation is associated with the accumulation of lipid peroxidation products1,2 and induction of inflammatory genes,3 inactivation of NO·resulting in endothelial dysfunction, 4,5 activation of matrix metalloproteinases,6 and increased smooth muscle cell growth.7 …

Endothelial function fluctuates with diurnal variation in the frequency of ischemic episodes in patients with variant angina.

The aim of the present study was to investigate whether there is diurnal fluctuation in the endothelial function of patients with variant angina (VA). Coronary spasm is induced by acetylcholine and is promptly relieved by nitroglycerin. Thus, it is possible that endothelial dysfunction is involved in the pathogenesis of coronary spasm. Furthermore, the frequency of ischemic episodes is known to display diurnal variation. Flow-mediated, endothelium-dependent vasodilation of the brachial arteries was measured in the early morning (6 AM), afternoon (2 PM) and evening (8 PM) in 20 patients with VA (mean age 54.5 years; 10 men and 10 women) and in 20 control subjects (mean age 54.2 years; 10 men and 10 women). All patients underwent 24-h ambulatory electrocardiographic monitoring during the study. Flow-mediated vasodilation in patients with VA was deteriorated by the early morning and improved by the afternoon (patients with VA at 8 PM vs. 6 AM vs. 2 PM: 7.8 +/- 2.1% (p < 0.01 vs. VA at 6 AM) vs. 5.4 +/- 2.3% vs. 8.8 +/- 1.9% (p < 0.01 vs. VA at 6 AM); control subjects: 9.5 +/- 2.8% vs. 9.0 +/- 2.2% vs. 9.9 +/- 1.9%, respectively). The frequency of spontaneous ischemic episodes was highest from midnight to morning and was lowest from morning to late afternoon (4 PM to midnight: 7 episodes; midnight to 8 AM: 25 episodes; 8 AM to 4 PM: 3 episodes). There is diurnal fluctuation in endothelial function, which is associated with variation in the frequency of ischemic episodes.

Relation of heart rate dynamics to the occurrence of myocardial ischemia after coronary artery bypass grafting

Postoperative myocardial ischemia is a common finding after coronary artery bypass grafting (CABG) and is associated with an adverse short-term clinical outcome. The reasons and pathophysiologic background for the occurrence of ischemia after CABG are not well established. We tested the hypothesis that altered heart rate (HR) behavior precedes the onset of myocardial ischemic episodes in patients after CABG. Time-domain HR variability measurements, along with analysis of Poincaré plots and fractal scaling analysis were assessed in 40 CABG patients from 48-hour postoperative Holter recordings. Twenty patients experienced 195 ischemic episodes during the postoperative course. In the univariate analysis of HR variability measurements of the first postoperative day (POD), the increased ratio between the short-term (SD1) and long-term (SD2) HR variability analyzed from the Poincaré plot and the decreased short- and intermediate-term fractal scaling exponents α 1 and α 2 were significantly associated with ischemia during the study period (p <0.01, p <0.05, and p <0.05, respectively). In the multivariate model, the increased SD1/SD2 ratio of the first POD was the most powerful independent predictor of all possible confounding variables for the occurrence of postoperative ischemia (corresponding to a change of 0.15 U; odds ratio 2.2 and 95% confidence interval 1.2 to 5.7; p <0.01). Altered HR dynamics have been associated with myocardial ischemic episodes in patients after CABG, suggesting that the autonomic nervous system has an important role in the pathogenesis of myocardial ischemia in the postoperative phase of CABG.

Efficacy of clonidine for prevention of perioperative myocardial ischemia: a critical appraisal and meta-analysis of the literature.

There is a belief that clonidine may be effective in reducing perioperative myocardial ischemic events, although the results of several trials are conflicting. The aim of the current study was to provide a systematic review of randomized controlled trials that tested the efficacy of clonidine in this regard. Data was collected from a MEDLINE search of English-language studies published from 1980 to 1999 and a manual search of bibliographies from retrieved articles. A total of 28 studies were assessed. According to the selection criteria (study design, population, intervention, and outcome) and a quality scoring system, seven studies were finally included in the meta-analysis. After homogeneity was established by Q value, the data were then combined using the fixed-effects model. The pooled odds ratio was calculated. A subgroup analysis based on the types of surgery and administration route was also performed to qualify the results. The results were expressed as odds ratio and 95% confidence interval. Heterogeneity of outcome data was negative in the trials. The pooled odds ratio was 0.49 (95% confidence interval 0.34-0.71). In the subgroup analysis, clonidine reduced the incidence of myocardial ischemia in patients undergoing cardiac and noncardiac surgery. Rates of bradycardia were similar in clonidine and placebo groups. The meta-analysis suggests that perioperative clonidine reduces cardiac ischemic episodes in patients with known, or at risk of, coronary arterial disease without increasing the incidence of bradycardia. Therefore, these findings strongly justify planning and execution of a definitive study seeking the benefits of clonidine.

Impact of daily life myocardial ischemia in patients with chronic reversible and irreversible myocardial dysfunction

Repetitive myocardial ischemia during daily life has been suggested as the underlying mechanism of reversible myocardial dysfunction, which may progress into a hibernating state. Thirty-seven patients with ischemic cardiomyopathy (ejection fraction 35 ± 7%) underwent positron emission tomography (N-13 ammonia and 18-F-fluoro-2-deoxy-glucose [FDG]) and exercise testing before coronary artery bypass grafting (CABG) and 48- hour ambulatory electrocardiographic monitoring to detect ischemia before CABG and 6 months postoperatively. Reversibility of regional myocardial dysfunction was detected by echocardiographic follow-up at 5 days, 2 months, and 6 months after the operation. Preoperatively, ischemic episodes during daily activities were more common (2 [25th to 75th percentiles 0 to 4] vs 0 episodes, p <0.01) and duration of ischemia longer (9 [25th to 75th percentiles 0 to 37] vs 0 [25th to 75th percentiles 0 to 1] minutes, p <0.02) in patients with reversible dysfunction (n = 15) than in patients with irreversible dysfunction (n = 22). The number of ischemic episodes per patient correlated with the numbers of reversibly dysfunctional segments (p = 0.003), viable segments as seen by positron emission tomography (p <0.05), and flow-metabolic mismatch segments (p <0.05). CABG eliminated ambulatory ischemic episodes in patients with reversible dysfunction (0 episodes, p <0.05 vs before CABG). Preoperatively, all patients with reversible dysfunction had a positive exercise test (14 of 15 patients), whereas daily life ischemia was present in 60% of patients. Reversibly dysfunctional segments in patients with ambulatory ischemia had faster recovery of function (15 of 28 patients vs 2 of 12 patients recovered at 5 days, p <0.05), higher FDG uptake (0.86 ± 0.19% vs 0.71 ± 0.24%, p <0.05) than in patients without ambulatory ischemia, whereas perfusion was similar (0.63 ± 0.20 and 0.62 ± 0.19 ml/g/min). Thus, exercise-induced myocardial ischemia is associated with reversibility of myocardial dysfunction, but not all patients with reversible ischemic cardiomyopathy have ischemic attacks during daily life.

Does a circadian variation occur in myocardial ischemia over 48 hours in patients with unstable angina?

To study the incidence of and variation in myocardial ischemia over 48 hours in patients with unstable angina. Thirty-nine patients with unstable angina underwent long-term electrocardiography for 48 hours. The number of events and the period of time of ischemia (in minutes) were analyzed for the 48 hours, in two periods of 24 hours, and in periods of 4 hours. We analyzed 1755.8 hours of monitoring tapes, and ischemic episodes were detected in 18 (46.2%) patients, corresponding to 173 ischemic episodes, allowing the evaluation of 1304 minutes of ischemia.only 4 of which were (2.2%) symptomatic, Considering the entire period of time of recording and the predetermined time intervals, we observed a higher number of ischemic episodes (38) and a longer duration of ischemia (315.4 minutes) between 11:00 am and 3:00 pm. However, no significant differences occurred among the values in the different intervals. Long-term electrocardiography over 48 hours showed a high incidence (97.8%) of silent ischemic episodes in patients with unstable angina. No evidence of a circadian variation of myocardial ischemia in unstable angina was observed.

Changes in autonomic nervous activity prior to spontaneous coronary spasm in patients with variant angina.

Although the autonomic nervous system has been implicated in the genesis of coronary spasm, the precise mechanism by which it serves as the trigger of coronary spasm remains unclear. The aim of this study was to investigate changes in autonomic nervous activity associated with ischemic episodes in patients with variant angina (VA). Heart rate variability (HRV) on Holter monitoring was analyzed during 17 ischemic episodes in 11 patients with VA. The parameters of HRV were measured during a 2-min period at various time intervals prior to the onset of ST-segment elevation. The low frequency (LF) and high frequency (HF) components of the HRV, LF/HF ratio, mean RR interval, and the coefficient of the RR interval variation (CV) were calculated for each time interval. Both the HF and the CV increased significantly in the 2 min prior to the onset of ST-segment elevation, suggesting heightened vagal activity. The LF/HF ratio, a measure of cardiac sympatho-vagal balance, did not change. The LF, a measure of sympathetic activity with vagal modulation, also did not change. The RR interval decreased significantly in the 2 min prior to the onset of ST-segment elevation. These results suggest that enhancement of both the vagal and the sympathetic nervous activity plays an important role in the initiation of coronary spasm.

Symptomatic and asymptomatic episodes of myocardial ischemia in patients with arterial hypertension

Symptomatic and asymptomatic episodes of myocardial ischemia in patients with arterial hypertension

Book Reviews

Part 1 introduction: ambulatory assessment - issues and perspectives the naturalistic approach in differential psychology - the consistency issue. Part 2 New methodologies: assessment of experience, activation, and cognitive performance related to the time of the day, setting, and situational consistencies a computer-assisted self-monitoring procedure for assessing stress-related behaviour under real-life conditions computer-assisted interaction diary on social networks, social support and interpersonal stress computer-assisted versus paper & pencil-based self-monitoring - compliance, reactivity, and reliability temporal analysis of speech patterns in the real world using the LOGOPORT interactive monitoring and contingency analysis of emotionally induced ECG changes - methodology and applications field trials oa an interactive ambulatory heart rate monito ambulatory assessment of parasympathetic/sympathetic balance by impedance cardiography concurrent assessment of blood pressure, heart rate, activity, subjective state, and free commentaries on important episodes in everyday life continuous assessment of finger blood pressure and other hemodynamic and behavioral variables in everyday life towards a comprehensive technology for the recording and analysis of multiple physiological parameters within their behavioral and environmental context laboratory-field studies for improvement of ambulatory monitoring methodology strategies and designs in ambulatory assessment. Part 3 Monitoring and assessment in the workplace: psychophysiological analysis of work strain and action-oriented patterns of coping validation studies of emotional, mental and physical strain components in the field psychophysiological analysis of the stress-strain processes under different break schedules during computer work. Part 4 Monitoring and assessment of patients: ambulatory assessment of clinical anxiety psychophysiological monitoring of transient ischemic episodes in patients with coronary heart disease ambulatory blood pressure monitoring - promises and limitations in behavioral medicine ambulatory monitoring of sleep apnea ambulatory assessment of subjective and objective symptoms of diabetic patients signal-contingent computer diary for the assessment of psychological precedents of migraine attacks.

Dexmedetomidine.

Pharmacological manipulation of the sympathetic tone has led to the synthesis of novel compounds to control stress-induced hemodynamic disorders. The use of alpha(2)-adrenoceptor agonists is particularly interesting in this regard, since these agents decrease sympathetic activity by reducing norepinephrine release from nerve terminals. Dexmedetomidine is a potent, highly selective alpha(2)-adrenoceptor agonist. Its use is associated with a decrease in heart rate and blood pressure both in animals and humans. Several lines of evidence suggest that this compound increases perioperative cardiovascular stability and reduces the incidence of ischemic episodes in patients with coronary artery disease. In addition to its cardiovascular properties, dexmedetomidine possesses anxiolytic, hypnotic/sedative, anesthetic-sparing and analgesic actions and is devoid of significant respiratory depressant effects. Targeted mutations of the alpha(2) receptor site indicate that the alpha(2A) subtype is primarily involved in its sedative and anesthetic-sparing effects. Because of these properties, dexmedetomidine may be particularly useful during the perioperative period, as well as for sedation of patients in critical care settings.

Disturbed Autonomic Activity Precedes Ischemic Episodes in Patients with Variant Angina

BackgroundWhile the autonomic nervous system is known to be involved in the pathogenesis of variant angina, the relationship between disturbed autonomic activity and ischemic episodes in patients with variant angina has not been determined.MethodsWe performed 24‐hour Holter monitoring and power spectral analysis of heart rate variability (HRV) in ten patients with variant angina. The low frequency (0.04–0.15 Hz [LF]) and high frequency (0.15–0.40 Hz [HF]) components of HRV were quantified. The ratio of LF to HF (LF/HF) and the coefficient of the RR interval variation (CV) were also calculated. We analyzed HRV every 10 minutes beginning 50 minutes before the onset of ischemic episodes confirmed by ST segment elevation.ResultsThe LF/HF from 40 to 30 minutes before ischemia was decreased compared with the value from 50 to 40 minutes before ischemia (0.80 ± 0.15 vs 1.63 ± 0.44, mean ± SE, P = 0.037). The LF/HF then began to increase, and the value from 20 to 10 minutes (2.91 ± 0.66) was significantly greater than that from 40 to 30 minutes (P &lt; 0.01). The CV was increased from 30 to 20 minutes before ischemia compared with the CV from 50 to 40 minutes (8.5%± 1.6% vs 5.2%± 0.8%, P = 0.033). The LF/HF and the CV remained increased until the onset of ischemia.ConclusionsData suggests that a disturbed autonomic nervous activity plays an important role in the initiation of coronary vasospasm in patients with variant angina. A.N.E. 1997;2(4):313–318