Slow Pulse Rate Research Articles

Transient Bradyarrhythmia

Amiodarone is a class III anti-arrhythmic drug which is commonly used in various cardiac arrhythmias. Hypothyroidism is one important complication linked with this drug. Herein, we recount a case of amiodarone-induced hypothyroidism, which presented as atrial fibrillation (AF) with slow ventricular response. A middle-aged gentleman was brought to the casualty in unconscious state. He was a known case of hypertension and on amiodarone treatment for AF for the past 2 years. On presentation, the patient had a slow pulse rate and his electrocardiogram was suggestive of AF with very slow ventricular beat. This was managed medically and a temporary cardiac pacemaker was instituted thereafter. In search of the cause for bradycardia, his thyroid function test depicted hypothyroidism with 2-fold raised thyroid-stimulating hormone and decreased levels of free tetraiodothyronine hormone, but the patient had no other features suggestive of hypothyroidism. Therefore, the patient was started on oral thyroxine hormone, which led to considerable pulse rate improvement.

Influence of systematic variations of the stimulation profile on responses evoked with a vestibular implant prototype in humans

Objective. To explore the impact of different electrical stimulation profiles in human recipients of the Geneva-Maastricht vestibular implant prototypes. Approach. Four implanted patients were recruited for this study. We investigated the relative efficacy of systematic variations of the electrical stimulus profile (phase duration, pulse rate, baseline level, modulation depth) in evoking vestibulo-ocular (eVOR) and perceptual responses. Main results. Shorter phase durations and, to a lesser extent, slower pulse rates allowed maximizing the electrical dynamic range available for eliciting a wider range of intensities of vestibular percepts. When either the phase duration or the pulse rate was held constant, current modulation depth was the factor that had the most significant impact on peak velocity of the eVOR. Significance. Our results identified important parametric variations that influence the measured responses. Furthermore, we observed that not all vestibular pathways seem equally sensitive to the electrical stimulus when the electrodes are placed in the semicircular canals and monopolar stimulation is used. This opens the door to evaluating new stimulation strategies for a vestibular implant, and suggests the possibility of selectively activating one vestibular pathway or the other in order to optimize rehabilitation outcomes.

Do estimated 24-h pulse pressure components affect outcome? The Ohasama study.

Twenty-four-hour ambulatory pulse pressure (PP) is a powerful predictor of outcome. We attempted to apply the recently described PP components, an elastic (elPP), and systolic stiffening (stPP) components from 24-h ambulatory blood pressure (BP) monitoring (AMBP), and examine their influence on outcome in the Ohasama study population. Included were participants of the Ohasama study without history of cardiovascular disease (CVD), who were followed-up for total and CVD mortality, and for stroke morbidity. The PP components were derived from 24-h SBP and DBP using a model based on the nonlinear pressure--volume relationship in arteries expressing pressure stiffness relationship. Outcome predictive power was estimated by Cox regression models; hazard ratio with 95% confidence interval (CI), applied to elPP, and stPP, adjusted for age, sex, BMI, smoking, alcohol drinking, diabetes mellitus, total cholesterol, antihypertensive treatment, and mean arterial pressure (MAP), whenever appropriate. Of 1745 participants (age 61.4 ± 11.6, 65% women), 580 died, 212 of CVD, and 290 experienced a stroke during 17 follow-up years. PP was strongly correlated with elPP (r = 0.89) and less so with stPP (r = 0.58), and the correlation between the two components was weak (r = 0.15). After the adjustment, hazard ratio of PP per 1 SD increment for total mortality, CVD mortality, and stroke morbidity were 1.095 (95% CI 0.973-1.232), 1.207 (1.000-1.456), and 0.983 (0.829-1.166), respectively. Corresponding hazard ratios and 95% CIs were nonsignificant for elPP, and stPP. However, among participants with median pulse rate 68.5 bpm or less (median, n = 872), total (327 deaths) and CVD (131 deaths) mortality were predicted by elPP (per 1 SD increment), hazard ratio 1.231 (95% CI, 1.082-1.401), and 1.294 (95% CI, 1.069-1.566), respectively. In the subgroup of treated participants with hypertension and pulse rate 68.5 or less bpm (n = 309), total (177 deaths) and CVD (77 deaths) mortality were predicted by elPP, hazard ratio of 1.357 (95% CI, 1.131-1.628), and 1.417 (95% CI, 1.092-1.839), respectively. Stroke morbidity was not predicted by either PP or the PP components. In a rural Japanese population, elPP but not stPP was predictive of total and CVD mortality even when adjusted for MAP and conventional risk factors in the subpopulation with slower pulse rate. This was mostly among the treated hypertensive patients.

ELASTIC COMPONENT OF 24 -HOUR OF PULSE PRESSURES PREDICTS CARDIOVASCULAR AND TOTAL MORTALITY IN THE OHASAMA STUDY

Objective: 24-hour ambulatory pulse pressure (PP) is a powerful predictor of outcome. We attempted to apply the recently described PP components, an elastic (elPP), and systolic stiffening (stPP) components from 24-hour ambulatory blood pressure (BP) monitoring (AMBP), and examine their influence on outcome in the Ohasama study populationDesign and method: Included were participants of the Ohasama study without history of cardiovascular disease (CVD), who were followed-up for total and CVD mortality, and for stroke morbidity. The PP components were derived from 24-hour systolic and diastolic BP using a model based on the nonlinear pressure-volume relationship in arteries that express pressure-stiffness relationship. Outcome predictive power, was estimated by Cox regression models hazard ratio (HR) with 95% confidence interval (CI), applied to elPP, and stPP, adjusted for age, gender, BMI, smoking, drinking, diabetes mellitus, total cholesterol, antihypertensive treatment, and mean arterial pressure (MAP). Results: Of 1745 participants (age 60.7 ± 11.6, 65% female), 580 died, 212 of CVD, and 290 experienced a stroke during 17 follow-up years. PP was strongly correlated with elPP (r = 0.89) and less so with stPP (r = 0.58), the correlation between the 2 components was weak (r = 0.15). After adjustment, PP (per 1 mmHg increment) HR of total and CVD mortality and stroke morbidity were, 1.01, 1.02, 1.0, 95%CI 1.00–1.03, 1.00–1.05, 0.98–1.02, respectively. Corresponding HRs and 95%CIs were nonsignificant for elPP, and stPP. However when stratified by pulse rate (PR) <=68.5 bpm (median, n = 872), total (327 deaths) and CVD (131 deaths) mortality were predicted by elPP (per 1 mmHg increment), HR 1.03 95%CI 1.01–1.05, and 1.040 95%CI 1.01–1.07 respectively. In the subgroup of treated participants with hypertension and PR<=68.5 bpm (n = 309), total (177 deaths) and CVD (77deaths) mortality were predicted by elPP, HR of 1.04 95%CI 1.02–1.07, and 1.05, 1.01–1.09 respectively. Stroke morbidity was not predicted by either PP or the PP components Conclusions: In a rural Japanese population elPP but not stPP, was predictive of total and CVD mortality even when adjusted for MAP and conventional risk factors in the subpopulation with slower pulse rate. This was mostly among the treated hypertensive patients.

Audit to See the Effect of Nicotine Addiction on Pulse Rate

Objective of present study was to see the effect of nicotine addiction on pulse rate. Nicotine can cause cardiovascular diseases and it also affect pulse rate by increasing its speed. So it was concluded that the docents who are addicted to tea have higher pulse rate and who are not addicted to tea they have normal or slow pulse rate.

Stimulus specific adaptation in the auditory system of insects: Can a single neuron learn?

Stimulus-specific adaptation (SSA) is the suppression of a neuron's activity to repetitive stimuli while maintaining responsiveness to infrequent signals. In Neoconocephalus katydids, one auditory interneuron (TN-1) shows strong SSA in oddball paradigms, when standard and oddball pulses differ in carrier frequency. SSA occurred for pulse rates from &amp;gt;140 Hz down to 1 Hz. At fast repetition rates (&amp;gt;100 Hz), responses to the common pulses ceased, while oddballs elicit single spikes. At slower rates (&amp;lt;50 Hz), both standard and oddball pulses elicited spiking, with responses to oddballs being significantly larger, comparable to SSA described in vertebrate hearing systems. At slow rates, SSA also occurred when the shape of standard and oddball pulses differed, while having identical spectral properties. We identified at least two dendritic mechanisms that contribute to SSA at fast pulse rates (&amp;gt;100 Hz). The mechanisms underlying SSA at slow pulse rates are less well understood; likely, dendritic Ca2 + -gated currents contribute to SSA at slow pulse rates. At slow rates, response reduction to repeated pulses resembles habituation as oddball pulses cause dishabituation, i.e., the response to the following standard pulse is larger than that to the preceding one. Whether this habituation is generated within TN-1 or by its synaptic inputs remains an open question.

Responsiveness of the Electrically Stimulated Cochlear Nerve in Children With Cochlear Nerve Deficiency.

This study aimed to (1) investigate the responsiveness of the cochlear nerve (CN) to a single biphasic-electrical pulse in implanted children with cochlear nerve deficiency (CND) and (2) compare their results with those measured in implanted children with normal-size CNs. Participants included 23 children with CND (CND1 to CND23) and 18 children with normal-size CNs (S1 to S18). All subjects except for CND1 used Cochlear Nucleus cochlear implants with contour electrode arrays in their test ears. CND1 was implanted with a Cochlear Nucleus Freedom cochlear implant with a straight electrode array in the test ear. For each subject, the CN input/output (I/O) function and the refractory recovery function were measured using electrophysiological measures of the electrically evoked compound action potential (eCAP) at multiple electrode sites across the electrode array. Dependent variables included eCAP threshold, the maximum eCAP amplitude, slope of the I/O function, and time-constants of the refractory recovery function. Slopes of I/O functions were estimated using statistical modeling with a sigmoidal function. Recovery time-constants, including measures of the absolute refractory period and the relative refractory period, were estimated using statistical modeling with an exponential decay function. Generalized linear mixed-effect models were used to evaluate the effects of electrode site on the dependent variables measured in children with CND and to compare results of these dependent variables between subject groups. The eCAP was recorded at all test electrodes in children with normal-size CNs. In contrast, the eCAP could not be recorded at any electrode site in 4 children with CND. For all other children with CND, the percentage of electrodes with measurable eCAPs decreased as the stimulating site moved in a basal-to-apical direction. For children with CND, the stimulating site had a significant effect on the slope of the I/O functions and the relative refractory period but showed no significant effect on eCAP threshold and the maximum eCAP amplitude. Children with CND had significantly higher eCAP thresholds, smaller maximum eCAP amplitudes, flatter slopes of I/O functions, and longer absolute refractory periods than children with normal-size CNs. There was no significant difference in the relative refractory period measured in these two subject groups. In children with CND, the functional status of the CN varied along the length of the cochlea. Compared with children with normal-size CNs, children with CND showed reduced CN responsiveness to electrical stimuli. The prolonged CN absolute refractory period in children with CND might account for, at least partially, the observed benefit of using relatively slow pulse rate in these patients.

YELLOWNESS IS A THREAT TO NEWBORN - A REVIEW

Jaundice is a very well-known disease found worldwide. Jaundice comes from the French word “Jaune” - which means yellow. In medical term, jaundice is known as icterus which is a Greek word. This is a very common disease in the population, which causes the yellowish or greenish pigmentation in the skin and whiteness in the eyes. This is a condition of hyperbilirubinemia in which the amount of bilirubin increases in the blood. In this case, the high amount of bilirubin is found in blood, and the disruption of the movement of bilirubin into the liver and out of the body causes jaundice. Different symptoms seen in this case are yellow skin, yellow/white eyes, dark or reddish urine, loss of appetite, bitter taste of tongue, pale faces, nausea, itching in skin, anfd slow pulse rate. Jaundice may be mild to severe. Different types of jaundice are seen like normal jaundice in newborn, hepatic jaundice, and post-hepatic Jaundice.

Evolutionary diversification of the auditory organ sensilla in Neoconocephalus katydids (Orthoptera: Tettigoniidae) correlates with acoustic signal diversification over phylogenetic relatedness and life history.

Neoconocephalus Tettigoniidae are a model for the evolution of acoustic signals as male calls have diversified in temporal structure during the radiation of the genus. The call divergence and phylogeny in Neoconocephalus are established, but in tettigoniids in general, accompanying evolutionary changes in hearing organs are not studied. We investigated anatomical changes of the tympanal hearing organs during the evolutionary radiation and divergence of intraspecific acoustic signals. We compared the neuroanatomy of auditory sensilla (crista acustica) from nine Neoconocephalus species for the number of auditory sensilla and the crista acustica length. These parameters were correlated with differences in temporal call features, body size, life histories and different phylogenetic positions. By this, adaptive responses to shifting frequencies of male calls and changes in their temporal patterns can be evaluated against phylogenetic constraints and allometry. All species showed well-developed auditory sensilla, on average 32-35 between species. Crista acustica length and sensillum numbers correlated with body size, but not with phylogenetic position or life history. Statistically significant correlations existed also with specific call patterns: a higher number of auditory sensilla occurred in species with continuous calls or slow pulse rates, and a longer crista acustica occurred in species with double pulses or slow pulse rates. The auditory sensilla show significant differences between species despite their recent radiation, and morphological and ecological similarities. This indicates the responses to natural and sexual selection, including divergence of temporal and spectral signal properties. Phylogenetic constraints are unlikely to limit these changes of the auditory systems.

Multivariate female preference tests reveal latent perceptual biases.

The question of why males of many species produce elaborate mating displays has now been largely resolved: females prefer to mate with males that produce such displays. However, the question of why females prefer such displays has been controversial, with an emerging consensus that such displays often provide information to females about the direct fitness benefits that males provide to females and/or the indirect fitness benefits provided to offspring. Alternative explanations, such as production of arbitrarily attractive sons or innate pre-existing female sensory or perceptual bias, have also received support in certain taxa. Here, we describe multivariate female preference functions for male acoustic traits in two chirping species of field crickets with slow pulse rates; our data reveal cryptic female preferences for long trills that have not previously been observed in other chirping species. The trill preferences are evolutionarily pre-existing in the sense that males have not (yet?) exploited them, and they coexist with chirp preferences as alternative stable states within female song preference space. We discuss escape from neuronal adaptation as a possible mechanism underlying such latent preferences.

Regular pulse rate but irregular heart rate?

The 12-lead ECG shows a ventricular bigeminy with right bundle branch block, which is evidence of a left ventricular origin. The inferior axis and repetitive monomorphic occurrence points to an origin from the outflow tract. Thus, the diagnosis is repetitive left ventricular outflow tract premature beats. This extrasystole can be found in healthy individuals and does not increase the risk of sudden cardiac death. However, due to the short coupling interval of the extrasystole there is almost no diastolic filling before the extrasystolic beat, thus leading to a pulse deficit which is aggravated by the lack of a subsequent sinus beat (postextrasystolic pause). The subsequent sinus beat is augmented due to postextrasystolic potentiation and a prolonged diastole. During bigeminy there is a 2:1 pulse deficit leading to the reported slow but regular pulse rates of the patient. Outflow tract premature beats often show a fixed coupling interval due to triggered activity during phase III of the action potential (early afterdepolarisation) and thus sometimes responds to calcium channel inhibitors such as verapamil. Beta-blockers may be effective but sides effects such as arterial hypotension decrease compliance, especially in young adults. Accordingly, in this patient, ablation of the arrhythmia was scheduled. For electrophysiological mapping, a deflectable mapping and ablation catheter was introduced retrogradely into the left ventricle and mapping of the earliest ventricular activity was performed during spontaneous ventricular premature beats. In this case, earliest activity was recorded above the aortic valve inside the left coronary sinus cusp. Pacing from this site revealed a similar 12-lead ECG morphology as during spontaneous ventricular premature beats. Due to the proximity to the left main coronary artery, a left coronary angiography catheter was positioned into the left main coronary artery (Fig. 1 and 2) and simultaneous visualisation during ablation at this site was performed to identify impeding damage to the coronary vessel [1]. Ablation was performed using an irrigated catheter and the arrhythmia terminated after 10 seconds of radiofrequency ablation (Fig. 3). On the right side of the ECG you can see ST elevation which is documented near the coronary artery. After the ablation, this completely resolved. Since then, the patient has been free of symptoms and repetitive Holter ECGs did not show a recurrence of the arrhythmia. Fig. 1 Ablation catheter in the ascending aorta below the left main coronary artery as visualised by a diagnostic angiography catheter (JL-4). Additional electrode catheters are positioned in the high right atrium and right ventricle. Due to the anatomical ... Fig. 2 Under such ablations at critical points, imaging from different levels is important to safely prevent injury to the coronary arteries. (LAD left anterior descending) Fig. 3 12-lead ECG with termination of the premature beats (arrow) under radiofrequency ablation. On the right side of the ECG you can see ST elevation (*) which is documented near the coronary artery. After the ablation, these completely resolved

Regular pulse rate but irregular heart rate?

The 12-lead ECG shows a ventricular bigeminy with right bundle branch block, which is evidence of a left ventricular origin. The inferior axis and repetitive monomorphic occurrence points to an origin from the outflow tract. Thus, the diagnosis is repetitive left ventricular outflow tract premature beats. This extrasystole can be found in healthy individuals and does not increase the risk of sudden cardiac death. However, due to the short coupling interval of the extrasystole there is almost no diastolic filling before the extrasystolic beat, thus leading to a pulse deficit which is aggravated by the lack of a subsequent sinus beat (postextrasystolic pause). The subsequent sinus beat is augmented due to postextrasystolic potentiation and a prolonged diastole. During bigeminy there is a 2:1 pulse deficit leading to the reported slow but regular pulse rates of the patient. Outflow tract premature beats often show a fixed coupling interval due to triggered activity during phase III of the action potential (early afterdepolarisation) and thus sometimes responds to calcium channel inhibitors such as verapamil. Beta-blockers may be effective but sides effects such as arterial hypotension decrease compliance, especially in young adults. Accordingly, in this patient, ablation of the arrhythmia was scheduled. For electrophysiological mapping, a deflectable mapping and ablation catheter was introduced retrogradely into the left ventricle and mapping of the earliest ventricular activity was performed during spontaneous ventricular premature beats. In this case, earliest activity was recorded above the aortic valve inside the left coronary sinus cusp. Pacing from this site revealed a similar 12-lead ECG morphology as during spontaneous ventricular premature beats. Due to the proximity to the left main coronary artery, a left coronary angiography catheter was positioned into the left main coronary artery (Fig. 1 and 2) and simultaneous visualisation during ablation at this site was performed to identify impeding damage to the coronary vessel [1]. Ablation was performed using an irrigated catheter and the arrhythmia terminated after 10 seconds of radiofrequency ablation (Fig. 3). On the right side of the ECG you can see ST elevation which is documented near the coronary artery. After the ablation, this completely resolved. Since then, the patient has been free of symptoms and repetitive Holter ECGs did not show a recurrence of the arrhythmia. Fig. 1 Ablation catheter in the ascending aorta below the left main coronary artery as visualised by a diagnostic angiography catheter (JL-4). Additional electrode catheters are positioned in the high right atrium and right ventricle. Due to the anatomical ... Fig. 2 Under such ablations at critical points, imaging from different levels is important to safely prevent injury to the coronary arteries. (LAD left anterior descending) Fig. 3 12-lead ECG with termination of the premature beats (arrow) under radiofrequency ablation. On the right side of the ECG you can see ST elevation (*) which is documented near the coronary artery. After the ablation, these completely resolved

Character State Reconstruction of Call Diversity in the Neoconocephalus Katydids Reveals High Levels of Convergence.

The katydid genus Neoconocephalus is characterized by high diversity of the acoustic communication system. Both male signals and female preferences have been thoroughly studied in the past. This study used Bayesian character state reconstruction to elucidate the evolutionary history of diverse call traits, based on an existing, well supported phylogenetic hypothesis. The most common male call pattern consisted of continuous calls comprising one fast pulse rate; this pattern is the likely ancestral state in this genus. Three lines of call divergence existed among the species of the genus. First, four species had significantly slower pulse rates. Second, five species had alternating pulse periods, resulting in a double pulse rhythm. Third, several species had discontinuous calls, when pulses were grouped into rhythmically repeated verses. Bayesian character state reconstruction revealed that the double-pulse pattern likely evolved convergently five times; the slow pulse rate also evolved four times independently. Discontinuous calls have evolved twice and occur in two clades; each of which contains reversals to the ancestral continuous calls. Pairwise phylogenetically independent contrast analyses among the three call traits found no significant correlations among the character states of the different traits, supporting the independent evolution of the three call traits.

The Diversity of Call Recognition: Selective Phonotaxis in Neoconocephalus ensiger

In many insect and anuran species, the temporal pattern of male calls encodes the species identity of the signaler and females use the temporal pattern to identify and approach conspecific mates. We studied the call recognition mechanism of Neoconocephalus ensiger in phonotaxis experiments conducted on a walking compensator. Stimuli were presented in a no-choice paradigm and female response strength quantified. The calls of N. ensiger have an unusually slow pulse rate (approximately 12 Hz) for this genus, which is a derived trait. Call models were attractive when pulse durations were between 25 and 55 ms and interval durations were between 19 and 99 ms. An amplitude attenuation depth of 6 dB was sufficient for females to detect the conspecific temporal pattern. The call recognition mechanism of N. ensiger differs strikingly from four other temporal recognition mechanisms previously described in Neoconocephalus, but is similar to call recognition in more distantly related taxa (including anurans) that have male calls with similar pulse period. This suggests that the evolution of call recognition mechanisms is more strongly influenced by signal parameters and/or neural constraints than by phylogenetic constraints.

Time computations in anuran auditory systems.

Temporal computations are important in the acoustic communication of anurans. In many cases, calls between closely related species are nearly identical spectrally but differ markedly in temporal structure. Depending on the species, calls can differ in pulse duration, shape and/or rate (i.e., amplitude modulation), direction and rate of frequency modulation, and overall call duration. Also, behavioral studies have shown that anurans are able to discriminate between calls that differ in temporal structure. In the peripheral auditory system, temporal information is coded primarily in the spatiotemporal patterns of activity of auditory-nerve fibers. However, major transformations in the representation of temporal information occur in the central auditory system. In this review I summarize recent advances in understanding how temporal information is represented in the anuran midbrain, with particular emphasis on mechanisms that underlie selectivity for pulse duration and pulse rate (i.e., intervals between onsets of successive pulses). Two types of neurons have been identified that show selectivity for pulse rate: long-interval cells respond well to slow pulse rates but fail to spike or respond phasically to fast pulse rates; conversely, interval-counting neurons respond to intermediate or fast pulse rates, but only after a threshold number of pulses, presented at optimal intervals, have occurred. Duration-selectivity is manifest as short-pass, band-pass or long-pass tuning. Whole-cell patch recordings, in vivo, suggest that excitation and inhibition are integrated in diverse ways to generate temporal selectivity. In many cases, activity-related enhancement or depression of excitatory or inhibitory processes appear to contribute to selective responses.

Bryde's whale calls recorded in the Gulf of Mexico

Bryde's whale calls recorded in the Gulf of Mexico

Widespread genetic linkage of mating signals and preferences in the Hawaiian cricket Laupala

The evolution of novel sexual communication systems is integral to the process of speciation, as it discourages gene flow between incipient species. Physical linkage between genes underlying male-female communication (i.e. sexual signals and preferences for them) facilitates both rapid and coordinated divergence of sexual communication systems between populations and reduces recombination in the face of occasional hybridization between diverging populations. Despite these ramifications of the genetic architecture of sexual communication for sexual selection and speciation, few studies have examined this relationship empirically. Previous studies of the closely related Hawaiian crickets Laupala paranigra and Laupala kohalensis have indirectly suggested that many of the genes underlying the difference in pulse rate of male song are physically linked with genes underlying the difference in female preference for pulse rate. Using marker-assisted introgression, we moved 'slow pulse rate' alleles from L. paranigra at five known quantitative trait loci (QTL) underlying male pulse rate into the 'fast pulse rate' genetic background of L. kohalensis and assessed the effect of these loci on female preference. An astounding four out of five song QTL predicted the preferences of female fourth-generation backcrosses, providing direct evidence for the extensive genetic linkage of song and preference in one of the fastest diversifying genera currently known.

Patterned sound therapy for the treatment of tinnitus

USING SOUND TO CURE TINNITUS Sound therapy, via either acoustic or electric stimulation, uses external sounds to provide short- and longterm relief from tinnitus. The interactions between external sounds and tinnitus are well established, as the external sounds can not only induce tinnitus, but can alter its perception as well. Excessive exposure to loud sounds is the single greatest risk associated with tinnitus onset, and for those with tinnitus, sound overexposure may exacerbate it. However, sounds used at safe levels can be highly beneficial to an individual with tinnitus. Sounds can not only distract a person’s attention away from tinnitus, but also affect the overall quality of the tinnitus. In some cases, people report noticeable changes in tinnitus pitch or quality following exposure to certain external sound sources. For example, a variety of sounds, ranging from constant, low-level background sounds mimicking running water to intermittent sounds mimicking fire crackling have been used to mask the overall perception of tin

Arrhythmias in Children

Arrhythmias in children can be classified according to their effect on central pulse: Fast pulse rate - tachyarrhythmia; Slow pulse rate - bradyarrhythmia; and Absent pulse is pulseless arrest (cardiac arrest). Tachyarrythmia may be narrow complex tachycardia (QRS duration ≤ 0.08 s): sinus tachycardia (ST), supraventricular tachycardia (SVT), atrial flutter or Wide-complex tachycardia (QRS duration >0.08 s): ventricular tachycardia (VT), SVT with aberrant intraventricular conduction. The choice of therapy depends on the patient's degree of hemodynamic instability. Attempt vagal stimulation, if patient is stable and if it does not unduly delay chemical or electrical cardioversion. Bradyarrhythmias include: sinus bradycardia, sinus node arrest with atrial, junctional and idioventricular escape rhythms and AV block. The emergency treatment of bradycardia depends on its hemodynamic consequences. If heart rate is <60 beats per minute with poor perfusion despite effective ventilation with oxygen, it may be treated with chest compressions, epinephrine through IV or endotracheal tube. If bradycardia persists or responds only transiently, consider a continuous infusion of epinephrine or isoproterenol and plan for emergency transcutaneous pacing. If bradycardia is due to vagal stimulation or primary A-V block, giving atropine may be beneficial.

103: CLUE: A Comparative Effectiveness Trial of Nicardipine Versus Labetalol Use In the Emergency Department

103: CLUE: A Comparative Effectiveness Trial of Nicardipine Versus Labetalol Use In the Emergency Department