Age- and sex-based reference ranges for non-invasive ventricular repolarisation parameters.

SummaryBackground Some electrocardiographic parameters are able to assess indirectly ventricular repolarisation homogeneity. It is consequently essential to discriminate between normal and abnormal values in clinical decision-making. Considering there is still not a consensus about normal cut-off values, the aim of this study was to document reference intervals in all age groups of a healthy population, providing for age- and sex-percentile tables, which can be used easily and quickly in clinical practice. Methods We evaluated repolarisation markers in 606 sex-matched participants aged 1 day–94 years. Each subject underwent a 12-lead electrocardiogram at rest, and the following parameters were measured: QT, corrected QT, QTpeak, Tpeak-Tend, Tpeak-Tend dispersion, Tpeak-Tend/QT and QTpeak/QT ratio. Results A relationship was demonstrated between age and QTpeak, Tpeak-Tend, QT and QTc. In children, QTpeak, Tpeak-Tend and QT intervals increased linearly with age. In adolescents, all the three parameters remained stable. In adults, QTpeak and QT showed a further significant increase. On the contrary, Tpeak-Tend interval was longer in adults aged between 20 and 64 years than in participants aged 65 years or over, but the difference was not statistically significant. Male vs female participants showed longer Tpeak-Tend intervals; this sex difference was not statistically significant at birth and during childhood, whereas it was in adolescents and in adults. Conclusions Repolarisation parameters showed age- and sex-based variations, which are important to know to differentiate normal from pathological values

Usefulness of QT dispersion in clinical practice

The measurement of QT dispersion in the surface electrocardiogram has been proposed as a non invasive method for assessing inhomogeneity of myocardial repolarization and has been linked to an increased risk of arrhythmic cardiac death. Several studies have evaluated the use of QTd in a wide variety of cardiac diseases and have reached conflicting conclusions regarding its clinical significance

Physical exercise and Sport activities in patients with and without coronary heart disease

Background: The quantity and intensity of physical activity required for the primary prevention of coronary heart disease remain unclear. Therefore, we examined the association between physical activity and coronary risk. Methods: We studied 100 patients with chest pain, 78 men and 22 women, not older than 65 years, admitted to a coronary care unit. Patients were subdivided in 3 groups: the first group included patients with acute myocardial infarction, the second group included patients with chronic heart disease, the third included patients with non-ischemic chest-pain. A questionnaire on daily physical activity was filled by each patient. Results: A significantly higher percentage of patients with myocardial infarction and coronary heart disease had a sedentary life style compared to patients of the third group. Compared with subjects without heart disease, a significantly higher percentage of patients of the first and second group covered a daily average distance shorter than 500 meters, while a significantly inferior percentage covered a distance longer than 1 Km every day. A significantly lower percentage of patients with coronary heart disease practised sport compared with the third group. At the time of hospitalization a very small percentage of coronary heart disease patients still practised sport. Conclusions: The association between physical activity and reduced coronary risk is clear; in order to obtain benefits it is sufficient just walking every day. Regarding physical activity, continuity is important: patients, who practised sport only in juvenile age, breaking off when older, may lose the obtained advantages

Acute exercise-induced changes in hemostatic and fibrinolytic properties: analogies, similarities, and differences between normotensive subjects and patients with essential hypertension

Following acute exercise, normotensive and hypertensive subjects both undergo changes in hemostatic and fibrinolytic properties, but the hypertensive patient’s response to exercise is exaggerated and prolonged, exposing them to increased cardiovascular risk during or immediately after unusual and strenuous exercise. Thrombotic complications are triggered by the activation of the autonomic sympathetic nervous system in a pathological milieu characterized by platelet α2-adrenergic receptors with increased responsiveness to circulating catecholamine, altered platelet profile and function, abnormal hemostatic parameters, impaired fibrinolytic potential, and endothelial dysfunction. The recovery period is particularly dangerous for triggering adverse cardiovascular events because the balance between the thrombotic and fibrinolytic systems is temporarily shifted toward increased pro-coagulative activity. This review highlights the analogies, similarities, and differences between normotensive and hypertensive subjects regarding the acute exercise-induced changes to the hemostatic and fibrinolytic properties, showing what differentiates essential hypertension from physiological status. Abbreviations : HT, hypertensive; METs, metabolic equivalents; min, minutes; MPA, monocyte-platelet aggregates; NT, normotensive; PAI-1, plasminogen activator inhibitor-1; tPA, tissue plasminogen activator; VO2 max, maximal oxygen consumption

Increased plasma levels of fibrinogen in acute and chronic ischemic coronary syndromes.

BACKGROUND: The aim of this study was to evaluate the pathophysiological role of fibrinogen in patients with chronic or acute ischemic coronary syndromes on the basis of epidemiological and clinical evidences showing the importance of fibrinogen as a risk factor for cardiovascular diseases and atherosclerosis progression. METHODS: We evaluated the behavior of plasma fibrinogen in 310 hospitalized patients with 1) acute myocardial infarction (n = 98); 2) unstable angina (n = 87); 3) chronic ischemic heart disease (n = 75); and 4) in controls without myocardial ischemia (n = 50). Fibrinogen was evaluated, by using the Clauss method, on day 1 and 5 during in hospital-stay and at 6-month follow-up in patients suffering from acute myocardial infarction. RESULTS: Plasma levels of fibrinogen were higher in patients with chronic ischemic heart disease (335.3 +/- 81.2 mg/dl, p < 0.001) and especially in patients with acute myocardial infarction (454.72 +/- 69.5 mg/dl, p < 0.00001) and unstable angina (382.6 +/- 101.3 mg/dl, p < 0.00025) in comparison with controls (271.28 +/- 62.4 mg/dl). Q wave myocardial infarction showed higher levels of fibrinogen than non-Q wave (461.3 +/- 95.8 vs 422.5 +/- 71.3 mg/dl, p < 0.02). Patients with acute myocardial infarction showed a further increase in fibrinogen on day 5 in comparison with entry levels (525.88 +/- 87.3 vs 454.7 +/- 69.5 mg/dl, p < 0.00001) regardless of the fibrinolytic treatment. Patients who died (n = 6) or had severe arrhythmias (n = 4) during in-hospital stay as well as those with post-infarction angina (n = 20) showed higher fibrinogen levels. CONCLUSIONS: Our results confirm the role of fibrinogen as a risk factor for ischemic heart disease, especially in patients with unstable angina and acute myocardial infarction. In the latter, elevated fibrinogen values seem also to be associated with a worsen prognosis during hospitalization

Influence of climatic variables on acute myocardial infarction hospital admissions

BACKGROUND: Seasonal peaks in acute myocardial infarction (AMI) incidence have been widely reported. Weather has been postulated to be one of the elements at the basis of this association. The aim of our study was to determine the influence of seasonal variations and weather on AMI hospital admissions. METHODS: We correlated the daily number of AMI cases admitted to a western Sicily hospital over twelve years and weather conditions on a day-to-day basis. Information on temperature, humidity, wind force and direction, precipitation, sunny hours and atmospheric pressure was obtained from the local Birgi Air Force base. A total of 3918 consecutive patients were admitted with AMI over the period 1987-1998 (2822 men, 1096 women; M/F: 2,58). RESULTS AND CONCLUSIONS: A seasonal variation was found with a significant winter peak. The results of multivariate Poisson analysis show in both sexes a significant association as regards the incidence relative ratio between the daily number of AMI hospital admission and minimal daily temperature and maximal daily humidity. The incidence relative ratios (95% confidence intervals) were, in males, 0.95 (0.92-0.98) (p<0.001) as regards minimal temperature and 0.97 (0.94-0.99) (p=0.017) as regards maximal humidity. The corresponding values in females were respectively 0.91 (0.86-0.95) (p<0.001) and 0.94 (0.90-0.98) (p=0.009). Environmental temperature, and also humidity, may play an important role in the pathogenesis of AMI. These data may help in understanding the mechanisms whereby AMI events are triggered and in organizing better the assistance to ischemic patients throughout the yea

Effects of green tea catechins and exercise training on body composition parameters

The impact of phytochemicals, as green tea catechins, on body composition measures has become a relevant topic as ongoing epidemiological evidence suggests their potential role in weight loss. Although catechins have been shown to modulate fat and energy metabolism, clinical effects of green tea consumption still remain controversial. Given the role played by physical exercise in weight management, it is important to determine whether the association of catechins and exercise is able to improve outcomes over and above the beneficial effects of exercise alone. Considering that scientific findings on this topic are not entirely consistent, aim of the present review was to assess the current scientific literature regarding the interplay between green tea catechins and exercise in overweight and obese populations. In particular, it was evaluated whether the addition of green tea supplementation to exercise training was able to further improve the exercise-induced changes in body composition parameters

IN-HOSPITAL COMPLICATIONS OF ACUTE MYOCARDIAL INFARCTION IN HYPERTENSIVE SUBJECTS

BACKGROUND: Recent studies have shown a worse in-hospital outcome in hypertensive than in normotensive patients with acute myocardial infarction (AMI), which has been attributed to more frequent complications. The aim of this study was to investigate clinical patterns, risk factors, and in-hospital complications in hypertensive and normotensive patients with AMI. METHODS: Of 4994 consecutive patients with AMI admitted to the intensive care unit, hypertensive patients with first infarction (n = 915; mean age 68.8 +/- 11.4 years) and 915 gender- and age-matched normotensive subjects were retrospectively studied. RESULTS: In the univariate analysis, hypertensive subjects presented more frequently non-Q-wave infarction and ST segment depression than did normotensive subjects, even if hypertensive subjects more frequently had diabetes, dyslipidemia, renal failure, peripheral artery disease, cerebrovascular disease, and chronic obstructive pulmonary disease (P < .01 for all). Hypertensive subjects less frequently presented with cardiogenic shock (4.0% v 11.6%; P < .01), atrioventricular block (4.9% v 7.4%; P = .02), ventricular fibrillation (2.2% v 3.7%; P = .04), cardiac rupture (0.1% v 0.9%; P = .02), and ventricular thrombosis (0.5% v 1.5%; P < .03), and a higher frequency of paroxysmal atrial fibrillation (9.2 v 5.6%; P < .01). Mortality was significantly higher in patients with anterior versus inferior infarction, for all normotensive and hypertensive subjects (13.7% v 7.1%; P < .001), but mortality was remarkably higher in normotensive than in hypertensive subjects (17.8% v 6.2%; P < .001), regardless of infarction site (anterior, 11.2% v 4.1%; P < .001; inferior, 4.4% v 1.9%; P < .001). CONCLUSIONS: Hypertensive subjects with first AMI have a better in-hospital outcome than age- and gender-matched normotensive subjects, perhaps due to a less severe extension of the infarction area or to a different pathophysiologic mechanism

Association between Tpeak-Tend/QT and major adverse cardiovascular events in patients with Takotsubo syndrome

Background:Conflicting results have been described in the scientific literature regarding the relationship between electrocardiographic parameters and complications in patients with Takotsubo syndrome (TTS). Aim of the present study was to investigate whether there is an association between markers of ventricular repolarization and major adverse cardiovascular events (MACE) during hospitalisation. Methods:A retrospective chart review was conducted on a sample of patients with diagnosis of TTS, based on the fulfilment of the revised Mayo Clinic criteria. MACE included acute heart failure, cardiogenic shock, sustained ventricular tachycardia, ventricular fibrillation, and death. The following parameters, assessed on the admission electrocardiogram, were analysed: ST-segment elevation, ST-segment depression, T wave inversion, presence of Q waves, QT interval, QT interval corrected for heart rate, QT-dispersion, Tpeak-Tend (Tpe) interval, Tpe dispersion, Tpe/QT ratio, and QTpeak/QT ratio. Results:Patients with MACE, compared to patients without MACE, showed more commonly anterior ST-segment elevation and had significantly higher values of Tpe/QT ratio. Low ejection fraction and Tpe/QT ratio &gt; 0.27 identified a sub-population of patients more likely to have MACE during hospitalisation. Conclusions:Tpe/QT ratio represents a useful electrocardiographic parameter in the acute phase of TTS