Diagnostic Value of the TpTe Interval in Children with Ventricular Arrhythmias

Background: The changes in the period of ventricular repolarization, i.e., QT interval, QTp (Q-Tpeak) and TpTe interval (Tpeak–Tend), make it possible to assess the electrical instability of the heart muscle, which may lead to the development of life-threatening ventricular arrhythmia. The aim of the study was to determine and evaluate the use of differences in T-wave morphology and durations of repolarization period parameters (QT, TpTe) in resting ECGs for children with ventricular arrhythmias. Methods: The retrospective analysis was made of the disease histories of 80 examined children with resting ECGs, which were admitted to the Children’s Cardiology Department. The study group consisted of 46 children aged 4 to 18 with ventricular arrhythmias and the control group consisted of 34 healthy children between 4 and 18 years of age, with no arrhythmias. Results: The duration of the TpTe interval was significantly (p < 0.001) longer in the group of children with ventricular arrhythmia with abnormal T-wave (bactrian/bifid, humid/biphasic) compared to the TpTe interval in children with ventricular arrhythmia with the normal repolarization period. The duration of the TpTe (p < 0.001), QTcB (p < 0.001) and QTcF (p < 0.001) intervals were significantly longer in the group of children with ventricular arrhythmias and with abnormal T-wave compared to the values of the TpTe, QTcB, and QTcF intervals of the control group with normal morphology of the repolarization period. Only the duration of the TpTe interval was significantly (p = 0.020) longer in the group of children with ventricular arrhythmia without clinical symptoms. Conclusions: Children with benign ventricular arrhythmias recorded on a standard ECG with prolonged TpTe and QT intervals and abnormal T-wave morphology require systematic and frequent cardiac check up with long term ECG recordings due to the possibility of future more severe ventricular arrhythmias. Further follow-up studies in even larger groups of patients are necessary to confirm the values of these repolarization parameters in clinical practice.

Do You Have a "Strict Purse"? The Routes to Meaning in Metaphor

<p>Theoretically there are two processing systems through which meaning can be found for a given statement: an effortless, associative processing system (meaning retrieval), or an effortful, analytical processing system (meaning construction). The current study investigated whether or not the context in which target (loosely figurative) word-pairs are presented can influence whether a person relies on associative or analytical processing to find their meaning. Participants were presented with target (loosely figurative) novel word-pairs and asked to judge them for meaningfulness. These target novel word-pairs were presented in different contexts: either mixed with clearly meaningful word-pairs or with additional novel word-pairs. By nature, meaning cannot be retrieved for novel word-pairs, so if a novel word-pair is to be found "meaningful," then its meaning must usually be constructed online (via the analytical processing system). Consistent with increased reliance on analytical processing, participants who saw target novel word-pairs mixed with additional novel word-pairs judged them meaningful more often than did participants who saw them mixed with clearly meaningful word-pairs. Participants who saw target novel word-pairs mixed with additional novel word-pairs also had more negative N400s to target novel word-pairs, indicating that they committed more semantic effort to the processing of these (again consistent with analytical processing). Associative processing does not involve attempts to construct new meaning for given word-pairs. Consistent with increased reliance on associative processing, participants who saw target novel word-pairs mixed with clearly meaningful word-pairs judged them meaningful less often than did participants who saw them mixed with additional novel word-pairs. These participants also had less negative N400s to target novel word-pairs, indicating that they committed less semantic effort to the processing of these (again fitting with associative processing). Further evidence for different contexts leading to differential processing of the same target novel word-pairs was provided by examination of wave morphology. Two distinctive patterns of neural activation were found in response to the same target novel word-pairs, differing depending on the context in which these appeared. Overall, the results of the current study were consistent with the hypothesis that context can influence which processing system is relied upon to find meaning for a given statement. This finding challenges contemporary models of meaning construction and metaphor comprehension by showing that context is essential to these processes and needs to be taken into consideration.</p>

Do You Have a "Strict Purse"? The Routes to Meaning in Metaphor

<p>Theoretically there are two processing systems through which meaning can be found for a given statement: an effortless, associative processing system (meaning retrieval), or an effortful, analytical processing system (meaning construction). The current study investigated whether or not the context in which target (loosely figurative) word-pairs are presented can influence whether a person relies on associative or analytical processing to find their meaning. Participants were presented with target (loosely figurative) novel word-pairs and asked to judge them for meaningfulness. These target novel word-pairs were presented in different contexts: either mixed with clearly meaningful word-pairs or with additional novel word-pairs. By nature, meaning cannot be retrieved for novel word-pairs, so if a novel word-pair is to be found "meaningful," then its meaning must usually be constructed online (via the analytical processing system). Consistent with increased reliance on analytical processing, participants who saw target novel word-pairs mixed with additional novel word-pairs judged them meaningful more often than did participants who saw them mixed with clearly meaningful word-pairs. Participants who saw target novel word-pairs mixed with additional novel word-pairs also had more negative N400s to target novel word-pairs, indicating that they committed more semantic effort to the processing of these (again consistent with analytical processing). Associative processing does not involve attempts to construct new meaning for given word-pairs. Consistent with increased reliance on associative processing, participants who saw target novel word-pairs mixed with clearly meaningful word-pairs judged them meaningful less often than did participants who saw them mixed with additional novel word-pairs. These participants also had less negative N400s to target novel word-pairs, indicating that they committed less semantic effort to the processing of these (again fitting with associative processing). Further evidence for different contexts leading to differential processing of the same target novel word-pairs was provided by examination of wave morphology. Two distinctive patterns of neural activation were found in response to the same target novel word-pairs, differing depending on the context in which these appeared. Overall, the results of the current study were consistent with the hypothesis that context can influence which processing system is relied upon to find meaning for a given statement. This finding challenges contemporary models of meaning construction and metaphor comprehension by showing that context is essential to these processes and needs to be taken into consideration.</p>

Slow pseudo sinus rhythm and atrial tachycardia of right superior venous pulmonary origin

ABSTRACT Paroxysmal atrial tachycardia usually presents as a sudden acceleration of the atrial rate combined with modifications of the P wave morphology. A 22-year-old patient presented with very fast and very slow atrial ectopic activity. He complained of repetitive episodes of fast tachycardia, some accompanied with dizziness. When the ectopic discharge was slow, no clear-cut difference between the sinus rate and the ectopic rate was seen and thus the atrial rhythm appeared quite regular. The ectopic focus was situated deep inside the right upper pulmonary vein (RSPV). After RSPV isolation a persistent sinus rhythm was established and since then the patient has been asymptomatic for 3 years. Thus, subtle changes in the P wave morphology without a significant change in the heart rate in patients presenting with palpitations can give a clue to the diagnosis of the tachycardia and the localization of the ectopic focus.

Current ECG Aspects of Interatrial Block

Interatrial blocks like other types of block may be of first degree or partial second degree, also named transient atrial block or atrial aberrancy, and third degree or advanced. In first degree, partial interatrial block (P-IAB), the electrical impulse is conducted to the left atrium, through the Bachmann’s region, but with delay. The ECG shows a P-wave ≥ 120 ms. In third-degree, advanced interatrial block (A-IAB), the electrical impulse is blocked in the upper part of the interatrial septum (Bachmann region); the breakthrough to LA has to be performed retrogradely from the AV junction zone. This explains the p ± in leads II, III and aVF. In typical cases of A-IAB, the P-wave morphology is biphasic (±) in leads II, III and aVF, because the left atrium is activated retrogradely and, therefore, the last part of the atrial activation falls in the negative hemifield of leads II, III and aVF. Recently, some atypical cases of A-IAB have been described. The presence of A-IAB is a risk factor for atrial fibrillation, stroke, dementia, and premature death.

Characterising the Photoplethysmography Pulse Waveform for Use in Human Neuroscience: The Hybrid Excess and Decay (HED) Model

Photoplethysmography (PPG) offers a widely-used, convenient and non-invasive approach to monitoring basic indices of cardiovascular function such as heart rate and blood oxygenation. However, while the pulse waveform, generated by PPG comprises features that are shaped by physiological and psychological factors, it is frequently overlooked in analyses of such data. We suggest that studies could be enriched by exploiting the possibilities afforded by a systematic analysis of PPG waveforms. To do this we initially require a robust and automated means of characterising it, thereby allowing us to examine variations across individuals and between different physiological and psychological contexts. We present a psychophysiologically-relevant model, the Hybrid Excess and Decay (HED) Model, which characterises pulse wave morphology in terms of three underlying pressure waves and a decay function. We show that these parameters capture PPG data with a high degree of precision and, moreover, are sensitive to specific, physiologically-relevant changes within individuals. We present the theoretical and practical basis for the model and demonstrate its performance when applied to a pharmacological dataset of 105 participants receiving intravenous administrations of the sympathomimetic drug isoproterenol (Isoprenaline). We conclude by discussing the possible value in using the HED model to complement standard measures of PPG outputs.