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Steven R. Neish, Richard A. Friedman and J. Timothy Bricker

Exercise testing has become an important method for evaluation of pediatric patients with known or suspected arrhythmias. It has proven useful in patients with exercise-induced symptoms, patients with congenital heart disease, and patients with pacemakers. Exercise has predictable effects on the normal electrocardiogram. Exercise can also bring out abnormalities in cardiac rhythm that may not be present at rest. The results of exercise testing can provide information that directs further therapy or evaluation. Exercise testing also helps to evaluate the efficacy of antiarrhythmic therapy in some patients.

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Mark S. Sklansky, James M. Pivarnik, E. O’Brian Smith, Jody Morris and J. Timothy Bricker

The effects of exercise training on hemodynamics and on the prevalence of arrhythmias in 11 asymptomatic children following tetralogy of Fallot (TOF) repair were investigated. Training consisted of three 30-min supervised exercise sessions per week for 8 consecutive weeks. Each subject exercised on a cycle ergometer and/or treadmill at 60–80% of measured peak heart rate (HR). Submaximal HR decreased (p < .0016), and maximal treadmill time increased, in every patient (p < .0004). Small decreases occurred in submaximal cardiac output (CO) (p < .094), VO2 (p < .047), and respiratory rate (RR) (p < .053). No significant change occurred in peak HR, peak VO2, or in resting LV end-diastolic dimension or posterior wall thickness. No significant change occurred in atrial or ventricular ectopy. It was concluded that young active children following repair of TOF can demonstrate aerobic training effects with an 8-week exercise program of three 30-minute sessions of moderately intense aerobic activity per week.

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Kelly L. Holzberger, Kim Keeley and Martin Donahue

and analyzes the conduction pathways within the heart. 5 Figure 1 —Sign and symptoms of supraventricular tachycardia (SVT). Treatment for SVT, like other arrhythmias, initially begins with medication. Beta blockers or calcium channel blockers are often prescribed to control the patient’s heart rate

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Falk Müller-Riemenschneider, Frank Andersohn, Sabine Ernst and Stefan N. Willich

Background:

There is controversy regarding the association of physical activity (PA) and atrial fibrillation (AF). This systematic review aims to summarize the evidence regarding the association of PA at different levels and AF.

Methods:

A structured search of databases was performed until December 2009. Studies that investigated the association between PA and AF were included and assessed by 2 researchers according to selection criteria and methodological quality. The overall quality of evidence was rated according to the Grade system.

Results:

Of 855 publications, 10 met the inclusion criteria. The risk of uncontrolled bias and confounding was profound and there was substantial heterogeneity regarding observed associations. One methodologically rigorous study reported substantial risk reductions associated with moderate intensity PA. Another indicated modest increases in risk with high levels of vigorous PA. Five methodologically less reliable studies reported large increases in risk due to regular sport practice.

Conclusion:

The overall quality of evidence indicating increases in risk of AF is low. Most reports of large increases in risk appear to be overestimated substantially. In light of the public health importance of regular PA, contradictory recommendations concerning the participation in PA should be considered cautiously before more rigorous studies have investigated this issue.

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Karla A. Kubitz and Daniel M. Landers

This study examined the effects of an 8-week aerobic training program on cardiovascular responses to mental stress. Dependent variables included electrocardiographic activity, blood pressure, electroencephalographic (EEG) activity, state anxiety, and state anger. Quantification of indicators of sympathetic, parasympathetic, and central nervous system activity (i.e., respiratory sinus arrhythmia, T-wave amplitude, and EEG activity, respectively) allowed examination of possible underlying mechanisms. Subjects (n = 24) were randomly assigned to experimental (training) and control (no training) conditions. Pre- and posttesting examined cardiorespiratory fitness and responses to mental stress (i.e., Stroop and mental arithmetic tasks). MANOVAs identified a significant effect on cardiorespiratory fitness, heart rate, respiratory sinus arrhythmia, and EEG alpha laterality. The results appear consistent with the hypothesis that enhanced parasympathetic nervous system activity and decreased central nervous system laterality serve as mechanisms underlying certain aerobic training effects.

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J. Timothy Bricker, Arthur Garson Jr., Stephen M. Paridon and Thomas A. Vargo

This study evaluated prospective exercise correlates of sinus node function in young individuals. Subjects for this study were 25 children and young adults who required cardiac catheterization for a symptomatic arrhythmia. Measurements of sinus node function at elechophysiological catheterization were the sinus node recovery time (SNRT) and sinoatrial conduction time (SACT). Maximal exercise testing was performed using a Bruce treadmill protocol the day prior to cardiac catheterization. Exercise measurements included resting heart rate, peak heart rate, cardiac acceleration from rest to 3 minutes, from rest to 6 minutes, from rest to peak, and from 3 to 6 minutes, cardiac deceleration from peak to 1 minute postexercise, deceleration for each minute of recovery, recovery heart rates for each of 5 minutes postexercise, heart rate at which respiratory exchange ratio >1.0 and slope of the heart rate – VO2 curve. Exercise testing did not predict intracardiac measures of sinus node function either as a group (“normal” vs. “abnormal” groups) or individually.

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Hans U. Wessel, Janette F. Strasburger and Brett M. Mitchell

We have developed normal standards for the Bruce exercise (EX) protocol since a review of 875 studies in patients with congenital or acquired heart disease showed that only 5.1% achieved the predicted 50th percentile for EX time of the standards reported by Cumming, Everatt, and Hastman (Am. J Cardiol 41:69, 1978). Our data are based on 160 males and 103 females, age 4–18 years who met the following criteria: trivial or no heart disease, maximal effort, maximal EX heart rate (HR) > 180 beats/min, and normal resting and EX ECG without arrhythmia. The ECG was monitored continuously and HR computed from the ECG and the end of each minute of EX. Comparison with the predicted data of Cumming et al. for each age group by stage showed essentially identical submaximal EX heart rates but slightly lower maximal HR (–2%), which averaged 197 beats per minute in males and females. EX times were on average 15% lower than the predicted 50th percentile for most age groups in males and females. We developed regression equations, which predict exercise time from age and body size or age, body size and 2nd stage exercise heart rate. They better reflect the capabilities of untrained, asymptomatic children and adolescents seen in our laboratory in the 1990s than the Canadian data of 1978.

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Laurent Mourot, Nicolas Fabre, Aldo Savoldelli and Federico Schena

To determine the most accurate method based on spectral analysis of heart-rate variability (SA-HRV) during an incremental and continuous maximal test involving the upper body, the authors tested 4 different methods to obtain the heart rate (HR) at the second ventilatory threshold (VT2). Sixteen ski mountaineers (mean ± SD; age 25 ± 3 y, height 177 ± 8 cm, mass 69 ± 10 kg) performed a roller-ski test on a treadmill. Respiratory variables and HR were continuously recorded, and the 4 SA-HRV methods were compared with the gas-exchange method through Bland and Altman analyses. The best method was the one based on a time-varying spectral analysis with high frequency ranging from 0.15 Hz to a cutoff point relative to the individual’s respiratory sinus arrhythmia. The HR values were significantly correlated (r 2 = .903), with a mean HR difference with the respiratory method of 0.1 ± 3.0 beats/min and low limits of agreements (around –6/+6 beats/min). The 3 other methods led to larger errors and lower agreements (up to 5 beats/min and around –23/+20 beats/min). It is possible to accurately determine VT2 with an HR monitor during an incremental test involving the upper body if the appropriate HRV method is used.

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1990 2 3 209 229 10.1123/pes.2.3.209 Research Exercise Testing in Patients with Arrhythmias Steven R. Neish * Richard A. Friedman * J. Timothy Bricker * 8 1990 2 3 230 248 10.1123/pes.2.3.230 Research Articles Validation of the Caltrac Movement Sensor Using Direct Observation in Young Children

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* Ginny Dahlstrom * 5 1994 6 2 178 187 10.1123/pes.6.2.178 Exercise Training Hemodynamics and the Prevalence of Arrhythmias in Children Following Tetralogy of Fallot Repair Mark S. Sklansky * James M. Pivarnik * E. O’Brian Smith * Jody Morris * J. Timothy Bricker * 5 1994 6 2 188 200 10