Are T-Inversions in Chest Leads Always Benign?

Non peer reviewe

Antenatal hemodynamic findings and heart rate variability in early school-age children born with fetal growth restriction

Background: According to epidemiological studies, impaired intrauterine growth increases the risk for cardiovascular morbidity and mortality in adulthood. Heart rate variability (HRV), which reflects the autonomic nervous system function, has been used for risk assessment in adults while its dysfunction has been linked to poor cardiovascular outcome. Objective: We hypothesized that children who were born with fetal growth restriction (FGR) and antenatal blood flow redistribution have decreased HRV at early school age compared to their gestational age matched peers with normal intrauterine growth. Study design: A prospectively collected cohort of children born with FGR (birth weight = -2SD. Conclusions: Early school age children born with FGR and intrauterine blood flow redistribution demonstrated altered heart rate variability. These prenatal and postnatal findings may be helpful in targeting preventive cardiovascular measures in FGR.Peer reviewe

Psyykenlääkkeet ja sydän

Vertaisarvioitu. English summaryMonet masennus- ja psykoosilääkkeet pidentävät QT-aikaa ja voivat siten altistaa käyttäjänsä äkkikuolemalle. Näiden lääkkeiden aloitus edellyttää riskinarviointia ja jatkuva käyttö muun muassa EKG-seurantaa. Varsinkin klotsapiini voi aiheuttaa kardiomyopatian tai ennen sitä myokardiitin, jonka ilmetessä lääkitys kannattaa keskeyttää. Monet psykoosilääkkeet huonontavat kardiologista riskiprofiilia, sillä ne lisäävät painoa ja muuttavat glukoosi- ja lipidiaineenvaihduntaa. Psyykenlääkehoitoja aloitettaessa kannattaa tehdä kardiovaskulaarinen riskinarvio, ja heti, kun potilaan psyykkinen tila sen sallii, puuttua erityisesti tupakointiin ja painon lisääntymiseen elintapainterventiolla tai jopa lääkitystä muuttamalla. Psyykenlääkkeiden sekä sydän- ja verisuonitautilääkkeiden välillä esiintyy merkittäviä yhteisvaikutuksia. Eräät masennuslääkkeet voivat aiheuttaa vuotokomplikaatioita tukosta estävien lääkkeiden ja antikoagulanttien kanssa. Yhteisvaikutusriski on erityisen suuri monilääkityillä vanhuksilla.Peer reviewe

Measurement of heart rate variability: a clinical tool or a research toy?

AbstractOBJECTIVESThe objectives of this review are to discuss the diversity of mechanisms that may explain the association between heart rate (HR) variability and mortality, to appraise the clinical applicability of traditional and new measures of HR variability and to propose future directions in this field of research. There is a large body of data demonstrating that abnormal HR variability measured over a 24-h period provides information on the risk of subsequent death in subjects with and without structural heart disease. However, the mechanisms responsible for this association are not completely established. Therefore, no specific therapy is currently available to improve the prognosis for patients with abnormal HR variability. Reduced HR variability has been most commonly associated with a risk of arrhythmic death, but recent data suggest that abnormal variability also predicts vascular causes of death, progression of coronary atherosclerosis and death due to heart failure. A consensus is also lacking on the best HR variability measure for clinical purposes. Time and frequency domain measures of HR variability have been most commonly used, but recent studies show that new analysis methods based on nonlinear dynamics may be more powerful in terms of risk stratification. Before the measurement of HR variability can be applied to clinical practice and used to direct therapy, more precise insight into the pathophysiological link between HR variability and mortality are needed. Further studies should also address the issue of which of the HR variability indexes, including the new nonlinear measures, is best for clinical purposes in various patient populations

Relation between heart rate variability and spontaneous and induced ventricular arrhythmias in patients with coronary artery disease

AbstractObjectives. The aim of this study was to determine the relation between autonomic control of heart rate and the spontaneous occurrence and inducibility of ventricular arrhythmias in patients with coronary artery disease.Background. Low heart rate variability increases the risk of arrhythmic events. It is not known whether impaired autonomic heart rate control reflects alterations in functional factors that contribute to the initiation of spontaneous arrhythmias or whether it is the consequence of an anatomic substrate for reentrant tachyarrhythmias.Methods. Fifty-four patients with coronary artery disease with a history of sustained ventricular tachycardia (n = 25) or cardiac arrest (n = 29) were studied by 24-h ambulatory electrocardiographic recording and by programmed electrical stimulation. Heart rate variability was compared among the patients with and without spontaneous ventricular arrhythmias and with and without inducibility of sustained ventricular tachyarrhythmias.Results. Eight patients had a total of 21 episodes of sustained ventricular tachycardia on Holter recordings. Standard deviation of RR intervals and low frequency and very low frequency components of heart rate variability were significantly blunted in patients with sustained ventricular tachycardias compared with those without repetitive ventricular ectopic activity (p < 0.05, p < 0.01 and p < 0.05, respectively). However, no significant alterations were observed in heart rate variability before the onset of 21 episodes of sustained ventricular tachycardia. Heart rate variability did not differ between the patients with or without nonsustained episodes of ventricular tachycardia. In patients with frequent ventricular ectopic activity, low frequency and very low frequency power components were significantly blunted compared with those with infrequent ventricular ectopic activity (p < 0.01 and p < 0.001, respectively). Heart rate variability did not differ significantly between the patients with and without inducible sustained ventricular tachyarrhythmias.Conclusions. Impaired very low and low frequency oscillation of heart rate reflects susceptibility to the spontaneous occurrence of ventricular arrhythmias but may not reflect the instantaneous triggers for life-threatening arrhythmias or a specific marker of the arrhythmic substrate for ventricular tachyarrhythmias

Electrocardiogram Quality Classification based on Robust Best Subsets Linear Prediction Error

Abstract A computationally efficient electrocardiogram (EC

Nighttime ambulatory pulse pressure predicts cardiovascular and all-cause mortality among middle-aged participants in the 21-year follow-up

Office pulse pressure (PP) is a predictor for cardiovascular (CV) events and mortality. Our aim was to evaluate ambulatory PP as a long-term risk factor in a random cohort of middle-aged participants. The Opera study took place in years 1991-1993, with a 24-h ambulatory blood pressure measurement (ABPM) performed to 900 participants. The end-points were non-fatal and fatal CV events, and deaths of all-causes. Follow-up period, until the first event or until the end of the year 2014, was 21.1 years (mean). Of 900 participants, 22.6% died (29.6% of men/15.6% of women, p<.001). A CV event was experienced by 208 participants (23.1%), 68.3% of them were male (p<.001). High nighttime ambulatory PP predicted independently CV mortality (hazard ratio [HR] 2.60; 95% confidence interval [CI 95%] 1.08-6.31, p=.034) and all-cause mortality in the whole population (HR 1.72; Cl 95% 1.06-2.78, p=.028). In males, both 24-h PP and nighttime PP associated with CV mortality and all-cause mortality (24-h PP HR for CV mortality 2.98; CI 95% 1.11-8.04, p=.031 and all-cause mortality HR 2.40; CI 95% 1.32-4.37, p=.004). Accordingly, nighttime PP; HR for CV mortality 3.13; CI 95% 1.14-8.56, p=.026, and for all-cause mortality HR 2.26; CI 95% 1.29-3.96, p=.004. Cox regression analyses were adjusted by sex, CV risk factors, and appropriate ambulatory mean systolic BP. In our study, high ambulatory nighttime PP was detected as a long-term risk factor for CV and all-cause mortality in middle-aged individuals

Cardiac structural and functional profile of patients with delayed QRS transition zone and sudden cardiac death

Delayed QRS transition zone in the precordial leads of the 12-lead electrocardiogram (ECG) has been recently associated with increased risk of sudden cardiac death (SCD), but the underlying mechanisms are unknown. We correlated echocardiographic findings with ECG and clinical characteristics to investigate how alterations in cardiac structure and function contribute to this risk marker. From the ongoing population-based Oregon Sudden Unexpected Death Study (catchment population similar to 1 million), SCD cases with prior ECG available (n = 627) were compared with controls (n = 801). Subjects with delayed transition at V-5 or later were identified, and clinical and echocardiographic patterns associated with delayed transition were analysed. Delayed transition was present in 31% of the SCD cases and 17% of the controls. These subjects were older and more likely to have cardiovascular risk factors and history of myocardial infarction. Delayed transition was associated with increased left ventricular (LV) mass (122.7 +/- 40.2 vs. 102.9 +/- 33.7 g/m(2); P <0.001), larger LV diameter (53.3 +/- 10.4 vs. 49.2 +/- 8.0 mm; P <0.001), and lower LV ejection fraction (LVEF) (46.4 +/- 15.7 vs. 55.6 +/- 12.5%; P <0.001). In multivariate analysis, delayed transition was independently associated with myocardial infarction, reduced LVEF, and LV hypertrophy. The association between delayed transition and SCD was independent of the LVEF (OR 1.57; 95% CI 1.04-2.38; P = 0.032). The underpinnings of delayed QRS transition zone extend beyond previous myocardial infarction and reduced LVEF. Since the association with sudden death is independent of these factors, this novel marker of myocardial electrical remodelling should be explored as a potential risk predictor of SCD.Peer reviewe

Waveform prototype-based feature learning for automatic detection of the early repolarization pattern in ECG signals

Objective: Our aim was to develop an automated detection method, for prescreening purposes, of early repolarization (ER) pattern with slur/notch configuration in electrocardiogram (ECG) signals using a waveform prototype-based feature vector for supervised classification. Approach: The feature vectors consist of fragments of the ECG signal where the ER pattern is located, instead of abstract descriptive variables of ECG waveforms. The tested classifiers included linear discriminant analysis, k-nearest neighbor algorithm, and support vector machine (SVM). Main results: SVM showed the best performance in Friedman tests in our test data including 5676 subjects representing 45408 leads. Accuracies of the different classifiers showed results well over 90%, indicating that the waveform prototype-based feature vector is an effective representation of the differences between ECG signals with and without the ER pattern. The accuracy of inferior ER was 92.74% and 92.21% for lateral ER. The sensitivity achieved was 91.80% and specificity was 92.73%. Significance: The algorithm presented here showed good performance results, indicating that it could be used as a prescreening tool of ER, and it provides an additional identification of critical cases based on the distances to the classifier decision boundary, which are close to the 0.1 mV threshold and are difficult to label.Peer reviewe