Heart rate dynamics during and after exercise in postoperative congenital heart disease patients. Their relation to cardiac autonomic nervous activity and intrinsic sinus node dysfunction

Prognostic value of right ventricular dyssynchrony in adults with repaired tetralogy of Fallot

OBJECTIVE

Residual sequelae after surgical repair of tetralogy of Fallot (rTOF) affect clinical outcome. We investigated the prognostic impact of right ventricular (RV) dyssynchrony in adults with rTOF years after the surgical repair.

METHODS

Patients from the Swiss Adult Congenital HEart disease Registry were included. NT-proBNP levels, echocardiography, exercise testing and MRI data were collected. An offline strain analysis to quantify RV-ventricular and interventricular dyssynchrony was performed. The standard deviation of the time-to-peak shortening (TTP) of six RV segments defined the RV Dyssynchrony Index (RVDI). Maximal difference of TTP between RV and left ventricular segments defined the interventricular shortening delay (IVSD). Predictors of a composite adverse event (arrhythmias, hospitalisation for heart failure and death) were identified by multivariate Cox regression analysis. Their median values were used to create a risk score.

RESULTS

Out of 285 included patients (mean age 34±14 years), 33 patients (12%) experienced an adverse event during a mean follow-up of 48±21 months. No correlation was found between RVDI, IVSD and clinical events. NT-proBNP, right atrial area and peak heart rate were independent predictors of outcomes. After 4 years-follow-up, no adverse events occurred in patients at low risk (score=0 points), while an adverse event occurred in 62% of patients at high risk (score=3 points, p<0.001).

CONCLUSION

In our cohort of adults with rTOF, surrogates of RV dyssynchrony did not correlate with outcomes. A multimodality approach was effective in predicting the risk for adverse events.

Heart Rate Recovery Following Exercise Testing in Pediatric Patients with Acyanotic Repaired Congenital Heart Disease

Attenuated heart rate recovery (HRR) following peak exercise has been shown to be a predictor of mortality in populations of adults with Fontan palliation, coronary artery disease, heart failure, and heart transplantation. However, few have studied HRR in children and adolescents with congenital heart disease (CHD). This case-control study compared HRR patterns from exercise stress testing in children and adolescents with and without repaired acyanotic CHD (raCHD). Retrospective analysis included patients aged 10-18 years who had exercise testing between 2007 and 2017. The raCHD cohort included patients with Tetralogy of Fallot, transposition of the great arteries, coarctation, truncus arteriosus, atrioventricular septal defect, pulmonary outflow obstruction, aortic stenosis and/or insufficiency, or septal defects. Those in the control cohort were matched for age, sex, BMI, peak METs achieved, and peak heart rate (HR). HR at 1-min intervals throughout the 10-min recovery period and HRR patterns were analyzed. The study included n = 584 individuals (raCHD: n = 146), median age 14 years old, 67.1% male. The cohorts had similar resting and peak HRs. Linear mixed-effects models (LMM) suggested statistically significant cohort-by-time interaction for HR in exercise recovery, with the largest mean difference at minute-6 (2.9 bpm, p = 0.008). When comparing lesion types, LMM found no cohort or cohort-by-time interaction. While minute-6 of exercise recovery was statistically significant, the difference was 2.9 bpm and may not have clinical significance. These results suggest that HRR in pediatric raCHD patients should not vary from their healthy peers, and an attenuated HRR may not be directly attributed to underlying raCHD.

Management of a Residual VSD 60 Years after One of the First Operations Worldwide

Background  Although surgical closure of ventricular septal defect (VSD) is the gold standard treatment, patients are subjected to deterioration in the following decades. We will present here the first case in literature surviving 60 years after surgical VSD closure with a residual VSD and presenting again for surgery. Case Description  A 68-year-old male patient who underwent surgical closure of a perimembranous VSD in Berlin in 1959. Postoperatively, a small residual VSD was noticed, which was well tolerated over six decades. He presented 60 years postoperatively with severe aortic regurgitation, tricuspid regurgitation, and moderate mitral regurgitation.

Analysis of the recovery phase after maximal exercise in children with repaired tetralogy of Fallot and the relationship with ventricular function

Background

Few studies demonstrate delayed recovery after exercise in children and adults with heart disease. We assess the recovery patterns of gas exchange parameters and heart rate (HR) in children with repaired Tetralogy of Fallot (rToF) compared to healthy peers and investigate the correlation with ventricular function and QRS duration.

Methods

45 children after rToF and 45 controls performed a maximal incremental cardiopulmonary exercise test. In the subsequent recovery period, patterns of VO₂, VCO₂ and HR were analysed. Half-life time (T_1/2) of the exponential decay and drop per minute (Rec_min) were compared between groups. In the rToF group, correlations were examined between the recovery parameters and QRS-duration and ventricular function, described by fractional shortening (FS) and tricuspid annular plane systolic excursion (TAPSE) measured at baseline prior to exercise.

Results

Recovery of VO₂ and VCO₂ was delayed in rToF patients, half-life time values were higher compared to controls (T_1/2VO₂ 52.51 ±11.29 s vs. 44.31 ± 10.47 s; p = 0.001 and T_1/2VCO₂ 68.28 ± 13.84 s vs. 59.41 ± 12.06 s; p = 0.002) and percentage drop from maximal value was slower at each minute of recovery (p<0.05). Correlations were found with FS (T_1/2VO₂: r = -0.517; p<0.001; Rec_1minVO₂: r = -0.636, p<0.001; Rec_1minVCO₂: r = -0.373, p = 0.012) and TAPSE (T_1/2VO₂: r = -0.505; p<0.001; Rec_1minVO₂: r = -0.566, p<0.001; T_1/2VCO₂: r = -0.466; p = 0.001; Rec_1minVCO₂: r = -0.507, p<0.001), not with QRS-duration. No difference was found in HR recovery between patients and controls.

Conclusions

Children after rToF show a delayed gas exchange recovery after exercise. This delay correlates to ventricular function, demonstrating its importance in recovery after physical activity.

Determinants of Exercise Performance in Children and Adolescents with Repaired Tetralogy of Fallot Using Stress Echocardiography

Exercise performance is variable and often impaired in patients with repaired tetralogy of Fallot (rTOF). We sought to identify factors associated with exercise performance by comparing high to low performers on cardiopulmonary exercise testing (CPET) in patients with rTOF. We conducted a cross-sectional study of subjects presenting for CPET who underwent echocardiograms at rest and peak exercise. Patients with pacemakers and arrhythmias were excluded. Right ventricular (RV) global longitudinal strain was used as a measure of systolic function. Pulmonary insufficiency (PI) was assessed with the diastolic systolic ratio and the diastolic systolic time-velocity integral ratio by Doppler interrogation of the pulmonary artery. CPET measures included percent-predicted maximum [Formula: see text][Formula: see text], percent-predicted maximum work and oxygen pulse. High versus low performers were identified as those achieving [Formula: see text] of at least 80% or falling below, respectively. Differences in echocardiographic parameters from rest to peak exercise were examined using mixed-effects regression models. Compared to the low performers (n = 17), high performers (n = 12) were younger (12.8 ± 3.3 years vs. 18.3 ± 4.8 years), had normal chronotropic response (peak heart rate > 185 bpm) with greater heart rate reserve and superior physical working capacity. High performers also had a greater reduction in PI at peak exercise, despite greater PI severity at rest. Oxygen pulse was comparable between groups. For both groups, there was no association of PI severity and RV systolic function at rest with exercise parameters. There was no group difference in the magnitude of change in RV strain and diastolic parameters from rest to peak exercise. Chronotropic response to exercise appears to be an important parameter with which to assess exercise performance in rTOF. Chronotropic health should be taken into consideration in this population, particularly given that RV function and PI severity at rest were not associated with exercise performance.

Evaluation and management of bradycardia in neonates and children

Heart rate is commonly used in pediatric early warning scores. Age-related changes in the anatomy and physiology of infants and children produce normal ranges for electrocardiogram features that differ from adults and vary with age. Bradycardia is defined as a heart rate below the lowest normal value for age. Pediatric bradycardia most commonly manifests as sinus bradycardia, junctional bradycardia, or atrioventricular block. As a result of several different etiologies, it may occur in an entirely structurally normal heart or in association with concomitant congenital heart disease. Genetic variants in multiple genes have been described to date in the pathogenesis of inherited sinus node dysfunction or progressive cardiac conduction disorders. Management and eventual prognosis of bradycardia in the young are entirely dependent upon the underlying cause. Reasons to intervene for bradycardia are the association of related symptoms and/or the downstream risk of heart failure or pause-dependent tachyarrhythmia. The simplest aspect of severe bradycardia management is reflected in the Pediatric and Advanced Life Support (PALS) guidelines.

CONCLUSION

Early diagnosis and appropriate management are critical in many cases in order to prevent sudden death, and this review critically assesses our current practice for evaluation and management of bradycardia in neonates and children.

WHAT IS KNOWN

Bradycardia is defined as a heart rate below the lowest normal value for age. Age related changes in the anatomy and physiology of infants and children produce normal ranges for electrocardiogram features that differ from adults and vary with age. Pediatric bradycardia most commonly manifests as sinus bradycardia, junctional bradycardia, or atrioventricular block.

WHAT IS NEW

Management and eventual prognosis of bradycardia in the young are entirely dependent upon the underlying cause. Bradycardia may occur in a structurally normal heart or in association with congenital heart disease. Genetic variants in multiple genes have been described. Reasons to intervene for bradycardia are the association of related symptoms and/or the downstream risk of heart failure or pause-dependent tachyarrhythmia. Early diagnosis and appropriate management are critical in order to prevent sudden death.

Reduced long-term exercise capacity in young adults operated for ventricular septal defect

BACKGROUND

Ventricular septal defects are normally closed in early childhood, and post-surgically the patients are considered as healthy and fit as their peers. However, data are inconsistent. We exercise-tested a cohort of ventricular septal defect-operated patients and a group of matched controls to evaluate long-term physical fitness.

METHODS

Cardiopulmonary exercise capacity was tested on an ergometer cycle in 30 patients and 30 healthy age and gender-matched controls. Pulmonary ventilation and gas exchange were simultaneously measured breath-by-breath with Jaeger MasterScreen CPX® (CareFusion, San Diego, United States of America). During the test session, respiratory gas exchange was measured along with heart rate, blood pressure, and electrocardiogram. The endpoints were peak oxygen uptake, maximal workload, and ventilatory anaerobic threshold. The International Physical Activity Questionnaire and the SF-36 were applied for Health-Related Quality-of-Life assessment.

RESULTS

Ventricular septal defect-operated adults had a markedly lower peak oxygen uptake: mean 38.0(±8.2 ml O2/kg/minute) versus 47.9(±6.5 ml O2/kg/minute) in controls, p<0.01. Furthermore, ventilatory anaerobic threshold was impaired in ventricular septal defect patients: mean 25.3(±7.8 ml O2/kg/minute) versus 35.2(±7.7 ml O2/kg/minute) in controls, p<0.01. Maximal workload was reduced: mean 3.3(±0.7 W/kg) versus 4.0(±0.5 W/kg) in the control group, p<0.01. Lastly, ventricular septal defect patients had a significantly lower peak heart rate: mean 182(±8.8 beats/minute) versus 188(±9.0 beats/minute) in controls, p=0.03. Regarding Health-Related Quality of Life, the ventricular septal defect group had significantly lower scores in physical functioning, role physical, and social functioning.

CONCLUSION

Young adults with a surgically closed ventricular septal defect had a markedly reduced cardiopulmonary exercise capacity and a lower peak heart rate compared with controls.

Experience of decortication for restrictive hemodynamics in adults with congenital heart disease

We treated four postoperative adults with congenital heart disease with severe restrictive hemodynamics (RH), and performed decortication (DC) with the anticipation of some relief of the RH. The catheterizations before DC showed high central venous, and right and left ventricular end-diastolic pressures with "dip-and-plateau" pressure waveforms in the right and left ventricles. Upon myocardial histopathologic examination, moderate myocardial fibrotic change was demonstrated in two of three cases. DC led to decrease in type B natriuretic peptide levels in all cases, resulting in a decline in the central venous, right and left ventricular end-diastolic pressures in three cases. Successful DC-related relief of RH, dilatation of the ventricles with decline in central and end-diastolic pressures, was observed in only one case. Our limited DC-related hemodynamic improvement indicates a complexity of the severe RH, which may represent a unique intractable heart failure pathophysiology in intractable postoperative adult congenital heart disease.

The clinical characteristics of sudden cardiac arrest in asymptomatic patients with congenital heart disease

Sudden cardiac arrest (SCA) is a major cause of death in patients with congenital heart disease (CHD). Systemic ventricular dysfunction is a reported risk factor for SCA. We retrospectively analyzed the medical records of 46 patients (age >6 years) who experienced SCA. The following underlying cardiac defects were observed: biventricular repair with affected subpulmonary right ventricle (n = 18, 39 %), biventricular repair with systemic right ventricle and Eisenmenger syndrome (n = 6 each, 13 %), Fontan circulation and unrepaired CHD (n = 5 each, 11 %), and others (n = 6, 13 %). Twenty-one patients (46 %) had no history of arrhythmias, and 21 of 43 (49 %) showed systemic ventricular ejection fraction >55 %. According to the New York Heart Association classification, 18 patients (39 %) were class I and 28 (61 %) were class II/III. SCA occurred at a younger age in class I (16 ± 5 years) than in the other classes (23 ± 10 years; P = 0.004). QRS duration was similar between the groups (136 ± 38 vs. 141 ± 50 ms; P not significant). Seven patients in class I (15 % of all SCAs) had no history of arrhythmias or features of hemodynamic abnormalities. The proportion of patients with biventricular repair and affected subpulmonary right ventricle was higher than that of patients with other defects, and the majority of SCA patients had more complicated defects than a simple repaired ventricular septal defect or an atrial septal defect. No symptoms of heart failure, history of arrhythmias, or features of hemodynamic abnormalities were observed in 15 % of the patients who experienced SCA. Prolonged QRS duration might be a predictor of SCA even in asymptomatic CHD patients. Prevention of SCA in CHD patients may require more detailed evaluation than is typically considered necessary.

Pathophysiology of exercise heart rate recovery: a comprehensive analysis

Expanded use of exercise heart rate recovery (HRR) has renewed interest in the pathophysiology of heart rate control. This study uses basic physiologic principles to construct a unique model capable of describing the full time course of sympathetic and parasympathetic activity during HRR. The model is tested in a new study of 22 diverse subjects undergoing both maximal and submaximal treadmill exercise. Based on this analysis, prolongation of HRR involves changes within the sinus node, changes in sympathetic function, in parasympathetic function, and in the central mechanisms regulating autonomic balance. The methods may provide unique insight into alterations in autonomic control in health and disease.

Exercise testing and prescription in patients with congenital heart disease

The present paper provides a review of the literature regarding exercise testing, exercise capacity, and the role of exercise training in patients with congenital heart disease (CHD). Different measures of exercise capacity are discussed, including both simple and more advanced exercise parameters. Different groups of patients, including shunt lesions, pulmonary valvar stenosis, patients after completion of Fontan circulation, and patients with pulmonary arterial hypertension are discussed separately in more detail. It has been underscored that an active lifestyle, taking exercise limitations and potential risks of exercise into account is of utmost importance. Increased exercise capacity in these patients is furthermore correlated with an improvement of objective and subjective quality of life.

Evaluation of exercise capacity with cardiopulmonary exercise testing and BNP levels in adult patients with single or systemic right ventricles

INTRODUCTION

The aim of the study was to evaluate exercise capacity using cardiopulmonary exercise test (CpET) and serum B-type natriuretic peptide (BNP) levels in patients with single or systemic right ventricles.

MATERIAL AND METHODS

The study group included 40 patients (16 males) - 17 with transposition of the great arteries after Senning operation, 13 with corrected transposition of the great arteries and 10 with single ventricle after Fontan operation, aged 19-55 years (mean 28.8 ±9.5 years). The control group included 22 healthy individuals (10 males) aged 23-49 years (mean 30.6 ±6.1 years).

RESULTS

The majority of patients reported good exercise tolerance - accordingly 27 were classified in NYHA class I (67.5%), 12 (30%) in class II, and only 1 (0.5%) in class III. Cardiopulmonary exercise test revealed significantly lower exercise capacity in study patients than in control subjects. In the study vs. control group VO(2max) was 21.7 ±5.9 vs. 34.2 ±7.4 ml/kg/min (p = 0.00001), maximum heart rate at peak exercise (HRmax) 152.5 ±32.3 vs. 187.2 ±15.6 bpm (p = 0.00001), VE/VCO(2) slope 34.8 ±7.1 vs. 25.7 ±3.2 (p = 0.00001), forced vital capacity (FVC) 3.7 ±0.9l vs. 4.6 ±0.3 (p = 0.03), forced expiratory volume in 1 s (FEV(1)) 3.0 ±0.7 vs. 3.7 ±0.9l (p = 0.0002) respectively. Serum BNP concentrations were higher in study patients than in control subjects; 71.8 ±74.4 vs. 10.7 ±8.1 (pg/ml) respectively (p = 0.00001). No significant correlations between BNP levels and CpET parameters were found.

CONCLUSIONS

Patients with a morphological right ventricle serving the systemic circulation and those with common ventricle physiology after Fontan operation show markedly reduced exercise capacity. They are also characterized by higher serum BNP concentrations, which do not however correlate with CpET parameters.

Exercise performance after surgery for pulmonary atresia and intact ventricular septum

The objective of this study was to assess exercise performance in subjects born in Sweden between 1980 and 1995 and undergoing surgery for pulmonary atresia and intact ventricular septum and to identify determinants of exercise performance. Twenty-seven subjects, 16 with biventricular repair and 11 with univentricular palliation, and 28 age- and sex-matched controls completed cardiopulmonary exercise and lung function testing. Peak oxygen uptake was determined using a symptom-limited ramp bicycle exercise protocol. Regression analysis was performed to identify predictors of peak oxygen uptake (V'O(2)), The index group had lower peak V'O(2) (1.4 [median 0.8; range 2.5] l/min) than controls (1.9 [0.7; 3.1]; p < 0.05). Subjects without ventriculocoronary arterial communications (VCAC), corrected to biventricular circulation, had higher peak V'O(2), than the remaining index subjects. Decreased total lung capacity, low minute ventilation, and high physiologic dead space measured at peak exercise were all independent determinants of low peak V'O(2) Exercise capacity is generally decreased in subjects with pulmonary atresia and intact ventricular septum, although there are marked interindividual differences. Good exercise capacity was found in subjects without VCAC who had undergone biventricular repair. Decreased lung function was an unfavourable predictor of exercise capacity.