Postoperative Congenital Heart Disease Patients Research Articles

Airway Anomalies in Pediatric Patients After Surgery for Congenital Heart Disease: Single-Center Retrospective Cohort Study, Taiwan 2017-2020.

Airway anomalies increase risk of morbidity and mortality in postoperative pediatric patients with congenital heart disease (CHD). We aimed to identify airway anomalies and the association with intermediate outcomes in patients undergoing surgery for CHD. Single-center, hospital-based retrospective study in Taiwan, 2017-2020. A tertiary referral hospital in Taiwan. All pediatric patients who underwent surgery for CHD and were admitted to the PICU and had data about airway evaluation by cardiopulmonary CT scan or bronchoscopy. None. Among 820 CHD patients identified as having undergone airway evaluation in the PICU, 185 (22.6%) were diagnosed with airway anomalies, including structural lesions in 146 of 185 (78.9%), and dynamic problems were seen in 87 of 185 (47.0%). In this population, the explanatory factors associated with greater odds (odds ratio [OR]) of airway anomaly were premature birth (OR, 1.90; p = 0.002), genetic syndromes (OR, 2.60; p < 0.001), and in those with preoperative ventilator use (OR, 4.28; p < 0.001). In comparison to those without airway anomalies, the presence of airway anomalies was associated with higher hospital mortality (11.4% vs. 2.7%; p < 0.001), prolonged intubation days (8 d [1-27 d] vs. 1 d [1-5 d]; p < 0.001), longer PICU length of stay (23 d [8-81 d] vs. 7 d [4-18 d]; p < 0.001), and greater hazard of intermediate mortality (adjusted hazard ratio, 2.60; p = 0.001). In our single-center retrospective study, 2017-2020, between one-in-five and one-in-four of our postoperative CHD patients undergoing an airway evaluation had airway anomalies. Factors associated with greater odds of airway anomaly included, those with premature birth, or genetic syndromes, and preoperative ventilator use. Overall, in patients undergoing airway evaluation, the finding of an airway anomalies was associated with longer postoperative intubation duration and greater hazard of intermediate mortality.

Effects of Aerobic Exercise on Cardiopulmonary Function in Postoperative Patients with Congenital Heart Disease: A Meta-analysis.

This meta-analysis aimed to evaluate the impact of aerobic exercise on Peak VO2 (Oxygen Consumption) in postoperative patients with congenital heart disease (CHD). Besides this, we also tried to discover whether the improvement was influenced by patient ages, modes of supervision, types of exercise, the total dose of exercise, intervention periods, and types of CHD. Following the Population Intervention Comparison Outcome Study Design (PICOS) principle, a comprehensive search of the PubMed, Web of Science, Embase and Cochrane Library databases was conducted for randomized controlled trials (RCTs) evaluating the intervention effects of aerobic exercise on cardiopulmonary function in postoperative CHD patients until December 2023. This meta-analysis and publication bias tests were conducted using Stata 17.0, and the mean differences (MDs) with 95% confidence intervals (CIs) were used as effect sizes in statistics. A total of 15 RCTs (762 cases) were included in this meta-analysis, with 407 cases in the experimental group and 355 cases in the control group. Meta-analysis showed that aerobic exercise had a positive effect on Peak VO2 in postoperative CHD patients (MD = 2.14, 95% CI (1.34, 2.94), p 0.00001, I2 = 36%). The analysis of subgroups showed that intervention effects of aerobic exercise were superior to the control group when patients were 18 years old (MD = 2.53, p 0.00001), 18 years old (MD = 1.63, p = 0.01), under supervision (MD = 2.23, p 0.00001), unsupervised (MD = 2.06, p 0.00400), performing aerobic exercise (MD = 1.87, p = 0.0003), performing aerobic exercise combined with resistance training (MD = 2.57, p 0.00010), with a total dose of exercise 1440 minutes (MD = 2.45, p 0.00010), with the intervention period of 10-12 weeks (MD = 2.31, p 0.00001), with that 12 weeks (MD = 1.97, p = 0.00300), or with mixed types of CHD (MD = 2.34, p 0.00001). This meta-analysis did not deduct points for limitations, inconsistency, indirectness, imprecision, or publication bias, so the quality of evidence was graded as high. Aerobic exercise has a significantly positive impact on improving Peak VO2 in postoperative CHD patients. Moreover, it was found that for patients aged 18 and above, supervised aerobic exercise combined with resistance training, implemented for 10-12 weeks with a total dose of exercise 1440 minutes, had a better intervention effect on Peak VO2. This finding provided evidence-based medicine for the exercise rehabilitation of postoperative CHD patients, and explored the optimal exercise prescription for clinical practice as well. Registered on INPLASY No.202440016 (https://inplasy.com).

Enhancing Congenital Cardiac Postprocedural Care: A QR Code-Enabled Medical Bracelet Pilot Study.

The study aimed to evaluate the feasibility of using QR code-enabled medical bracelets for congenital heart disease (CHD) patients after hospital discharge to ensure quick communication of vital information to other medical personnel in emergency situations. A prospective study was conducted where QR code-enabled medical bracelets were given to families of postoperative pediatric cardiac patients. The QR code linked to a secure medical information sheet detailing the patient's cardiac history. Post-study surveys were completed by providers and families to assess their experiences with the bracelet. Of the 20 participants enrolled, 65% used the QR bracelet when seeking medical care. 55% found the bracelet useful, and 70% rated their experience as either "positive" or "very positive". Additionally, 80% recommended the bracelet for other patients undergoing cardiac procedures. The use of QR code bracelets for postoperative CHD patients has shown high levels of satisfaction from families and providers, potentially reducing medical errors and treatment delays.

Lactobacillus plantarum 24-7 improves postoperative bloating and hard stools by modulating intestinal microbiota in patients with congenital heart disease: a randomized controlled trial.

Gastrointestinal symptoms are a common postoperative complication in patients with congenital heart disease (CHD), affecting their postoperative recovery. Probiotic intervention may be a promising therapeutic approach to alleviate postoperative gastrointestinal symptoms. This study aimed to evaluate the potential of Lactobacillus plantarum 24-7 (L. plantarum 24-7) in mitigating postoperative gastrointestinal symptoms and promoting patient recovery. Adult CHD patients scheduled for surgical intervention were recruited. One hundred and twenty patients were randomized and received L. plantarum or placebo intervention twice daily for ten days. Gastrointestinal symptoms were assessed utilizing the Gastrointestinal Symptom Rating Scale (GSRS). Various postoperative variables were analyzed across both groups. Alterations in gut microbiota were evaluated through 16S rRNA sequencing. 112 patients completed the study, with 55 in the probiotic group and 57 in the placebo group. While the disparity in overall postoperative GSRS scores between the two groups did not reach statistical significance (P = 0.067), marked differences were observed in bloating (P = 0.004) and hard stool (P = 0.030) scores. Furthermore, individuals within the probiotic group exhibited lower postoperative neutrophil counts (P = 0.007) and concurrently higher lymphocyte counts (P = 0.001). Variations in the diversity and composition of postoperative gut microbiota were discerned between the probiotic and placebo groups. Remarkably, no probiotic-related adverse events were documented. Supplementation with L. plantarum was well-tolerated and demonstrated partial efficacy in ameliorating gastrointestinal symptoms in postoperative CHD patients. Modulating the gut microbiota may be a potential mechanism by which L. plantarum exerts clinical benefits.

Does sacubitril/valsartan work in children with heart failure?—a pilot study

BackgroundSacubitril/valsartan is an angiotensin receptor neprilysin antagonist (ARNI) approved for adult heart failure (HF). Its safety and efficacy in pediatric HF patients with cardiomyopathy or congenital heart disease are poorly understood. A pilot study was conducted to assess the clinical response, efficacy and safety of sacubitril/valsartan in this population at a tertiary care hospital in China.MethodsClinical parameters of patients who received sacubitril/valsartan from January 2019 to March 2023 were retrospectively collected and analyzed. Children over 1 month with a left ventricular ejection fraction (LVEF) &amp;lt;45% were included. Clinical efficacy was evaluated by echocardiographic LVEF, N-terminal pro-brain natriuretic peptide (NT-proBNP), New York Heart Association (NYHA) HF classification, HF re-admission, and death or transplantation. The initial dose was either 0.2 mg/kg bid or 0.4 mg/kg bid, with a target dose of 2.3 mg/kg bid or 3.1 mg/kg bid.ResultsForty-five patients (60% male) with a median age of 7.86 years were enrolled. Among them, 23 had congenital heart disease and 22 had cardiomyopathies. The median maintenance dose was 0.76 mg/kg. The primary endpoint of LVEF up to 45% was reached by 24 patients (53.3%). The median NT-proBNP was significantly decreased from 5,501.5 pg/ml to 2,241.5 pg/ml (P &amp;lt; 0.001), more in congenital heart disease than in cardiomyopathies (P = 0.032). The NYHA HF class was improved or remained stable in 42 cases (93.3%). During a median follow-up of 1.23 years, 13 patients (28.9%) were re-hospitalized due to HF, and 9 patients (20%) died or underwent transplantation. Hypotension was the main adverse event, occurring in 8 patients.ConclusionsSacubitril/valsartan may be effective in children with HF, but its safety and outcomes may differ depending on the etiology and anatomy of HF. Early post-operative congenital heart disease patients had less tolerance, more hypotension but better recovery and outcomes, while mid- and late- post-operative congenital heart disease patients and cardiomyopathy patients had less side effects but poorer clinical outcomes.

Standardization of Care Reduces Length of Stay for Postoperative Congenital Heart Disease Patients.

This single-center study utilized the Institute for Healthcare Improvement model to achieve the project aim. A diuretic wean protocol implemented in April 2018 entailed weaning to a homegoing diuretic regimen upon transfer from the cardiac intensive care unit to the inpatient step-down unit. A discharge milestone checklist implemented in September 2018 contained milestones necessary for discharge and an anticipated date of discharge. Outcome measures included aggregate median postoperative LOS and ∆LOS. Balancing measures included cardiac intensive care unit bounce back, pleural chest tube replacement, and readmission rates. Our baseline aggregate median postoperative LOS for the lesions studied was 6.2 days. Following diuretic protocol implementation, the aggregate median LOS decreased to 4.4 days. Baseline ∆LOS decreased from 5.5 to 0.42 days. Postoperative cost fell by an average of $11,874. Balancing measures demonstrated no unintended consequences. Implementation of a diuretic wean protocol led to sustained improvement in postoperative LOS, and ∆LOS in a subset of CHD patients with no unintended consequences supporting that standardization of postoperative care is effective for improvement efforts and can reduce overall practice variation.

Hyperlactatemia and Patient Outcomes After Pediatric Cardiac Surgery.

Elevated serum lactate level, or hyperlactatemia, is often associated with alterations in tissue perfusion, increased risk for complications in the postoperative period, and patient mortality. Measuring lactate levels is a relatively simple and noninvasive method of obtaining useful data about an impending clinical deterioration in a seemingly hemodynamically stable patient. This article evaluates the current practice of measuring lactate levels in pediatric patients after cardiac surgery and the association between these levels and patient outcomes. The article addresses periods of increased risk for decreased perfusion, the critical postoperative period, use of lactate measurements in conjunction with a risk scoring system for pre-and postoperative congenital heart disease patients, and the implications of elevated lactate levels in nursing practice.

Neurally Adjusted Ventilatory Assist Is Associated with Greater Initial Extubation Success in Postoperative Congenital Heart Disease Patients when Compared to Conventional Mechanical Ventilation.

Extubation failure is associated with considerable morbidity and mortality in postoperative patients with congenital heart disease (CHD). The study purpose was to investigate initial extubation success utilizing neurally adjusted ventilatory assist (NAVA) compared with pressure-regulated volume controlled, synchronized intermittent mandatory ventilation with pressure support (SIMV-PRVC + PS) for ventilatory weaning in patients who required prolonged mechanical ventilation (MV). Also, total days on MV, inotropes, sedation, analgesia, and pediatric intensive care unit (PICU) length of stay (LOS) between both groups were compared. This was a non-randomized pilot study utilizing historical controls (SIMV-PRVC + PS; n = 40) compared with a prospective study population (NAVA; n = 35) in a Level I PICU and was implemented to help future trial designs. All patients ( n = 75) required prolonged MV ≥96 hours due to their complex postoperative course. Ventilator weaning initiation and management was standardized between both groups. Ninety-seven percent of the NAVA group was successfully extubated on the initial attempt, while 80% were in the SIMV-PRVC + PS group ( p = 0.0317). Patients placed on NAVA were eight times more likely to have successful initial extubation (odds ratio [OR]: 8.50, 95% confidence interval [CI]: 1.01, 71.82). The NAVA group demonstrated a shorter median duration on MV (9.0 vs. 11.0 days, p = 0.032), PICU LOS (9.0 vs. 13.5 days, p < 0.0001), and shorter median duration of days on dopamine (8.0 vs. 11.0 days, p = 0.0022), milrinone (9.0 vs. 12.0 days, p = 0.0002), midazolam (8.0 vs. 12.0 days, p < 0.0001), and fentanyl (9.0 vs. 12.5 days, p < 0.0001) compared with the SIMV-PRVC + PS group. NAVA compared with SIMV-PRVC + PS was associated with a greater initial extubation success rate. NAVA should be considered as a mechanical ventilator weaning strategy in postoperative congenital heart disease (CHD) patients and warrants further investigation.

Dysnatremia in the Pediatric Cardiac Critical Care Unit: incidence and Outcomes in Post-operative Congenital Heart Disease Patients

Dysnatremia in the Pediatric Cardiac Critical Care Unit: incidence and Outcomes in Post-operative Congenital Heart Disease Patients

P6312Health related quality of life in post-operative congenital heart disease patients: experience from a low middle income country pakistan

P6312Health related quality of life in post-operative congenital heart disease patients: experience from a low middle income country pakistan

Comparison of pulmonary arterial wall properties between a congenital heart disease patient and a normal subject using in vivo pressure–diameter measurements: A feasibility study

Patients with congenital heart disease (CHD) requiring pulmonary valve and right ventricular intervention often suffer from residual lesions including pulmonary regurgitation or pulmonary artery (PA) obstruction after the placement of a patch or artificial conduit during surgery. These residual lesions can result in significant changes in the structure and function of the right ventricle (RV) and PA. Characterization of the material properties such as stress, strain, and compliance of the PA provides a quantitative assessment of RV–PA dysfunction and may aid in the longitudinal assessment of CHD patients. Thus, in this feasibility study, we aim to assess the variations in the material properties between the left PA (LPA) of a CHD patient, which was located in close proximity of the RV-main PA (MPA) homograft, and that of a normal subject (control) with a native LPA, using in vivo pressure–diameter data as input to a non-linear material model.In vivo LPA pressure and diameter were obtained using cardiac catheterization and cardiac MRI, respectively. This in vivo data was used in conjunction with a set of sample constitutive equations to define a 2D nonlinear anisotropic material model for the LPA. Subsequently, the model constants were predicted using an optimization algorithm and by applying an equilibrium condition to the LPA wall. The model was then used to predict the pressure–diameter and stress–stretch characteristics of the LPA of the patient and control.Based on the pressure–diameter curve predicted by the model, a greater slope was observed for the patient compared to the control, thus indicating a reduction in compliance of the patient's LPA due to the presence of a RV-MPA homograft. The stress–stretch characteristics indicated a higher stress for the patient's LPA compared to that of the control. Further, a difference between the circumferential and axial stresses confirmed the anisotropic nature of the artery.Thus, this feasibility study indicates that differences between a native and diseased PA can be evaluated using a material model in conjunction with in vivo pressure–diameter data. The material properties may provide insight into RV–PA dysfunction in post-operative CHD patients.

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Introduction: This study was performed to determine if the creation of a separate cardiac intensive care unit (CICU) within a pediatric intensive care unit (PICU) improves subjective measures of quality, consistency of care, and morale among nurses, nurse practitioners, intensivists, congenital cardiac surgeons, and cardiologists. Hypothesis: Creation of a separate CICU within a PICU will improve subjective measures of quality, consistency of care, and morale among nurses, nurse practitioners, intensivists, congenital cardiac surgeons, and cardiologists. Methods: An online survey was sent to all nurses, nurse practitioners, intensivists, congenital cardiac surgeons, and cardiologists who care for postoperative congenital heart disease patients in a 12 bed PICU at Kentucky Children’s Hospital. Survey participants answered questions on a five point ordinal scale regarding their comfort level caring for cardiac patients; their enjoyment caring for cardiac patients; the consistency of care among intensivists, nurses, surgeons, nurse practitioners, and cardiologists; and the quality of care provided by intensivists, surgeons, and cardiologists. Following the initial survey, a separate CICU was created within the PICU consisting of a separate intensivist, a nurse-driven rounding tool, protocol and clinical pathway implementation, with a dedicated cardiology and cardiac surgery team. Six months after the creation of the separate CICU service, the same survey was again sent to the same group of care providers. The results were analyzed using a proportional odds model fitted for each outcome. Results: There was no significant difference in type of respondent (p=0.33) or survey response rate (p=0.12). There was significant improvement in the consistency of care among cardiologists (p<0.01) and among intensivists (p<0.01). There was a trend toward statistical improvement in the consistency of care among nurses (p=0.08) and the likelihood of providers to take a position solely caring for CICU patients (p=0.10). There was no improvement in the quality of medical (p=0.73) or surgical (p=0.93) care. Conclusions: The creation of a separate CICU within a PICU improved consistency of care among intensivists and cardiologists.

Cardiac MRI in postoperative congenital heart disease patients

The survival of patients with congenital heart disease (CHD) has greatly improved over the past decades. Nevertheless, lifelong follow-up is required in postoperative CHD patients, and noninvasive imaging plays an important role during follow-up. Cardiac MR (CMR) imaging enables comprehensive imaging of cardiac function and anatomy, and helps to detect patients who need re-intervention and to predict clinical outcome. Postoperative CHD patients who are frequently referred for CMR evaluation include those with coarctation of the aorta, tetralogy of Fallot, transposition of the great arteries, and single ventricle patients after the Fontan procedure. This article reviews the current clinical role of CMR in these various subgroups of postoperative CHD patients. Furthermore, an overview of novel CMR applications and their clinical value in CHD patients is provided.

Electrical and mechanical dyssynchrony in pediatric pulmonary hypertension

Electrical and mechanical dyssynchrony are often seen in patients with left ventricular failure. In pediatric pulmonary hypertension (PH), right ventricular failure predominates; however, the prevalence of electrical and/or mechanical dyssynchrony in these patients is unknown. We examined the prevalence of electrical and mechanical dyssynchrony in pediatric PH patients. Medical records (including, functional status, electrocardiograms and echocardiograms) of pediatric PH patients were reviewed. QRS duration z-scores were calculated to determine electrical dyssynchrony. Echo vector velocity imaging was used to calculate the mechanical dyssynchrony index (DI). Seventy-seven PH patients (idiopathic pulmonary arterial hypertension [IPAH]: n = 26; congenital heart disease: n = 41; other: n = 10) were studied. Electrical dyssynchrony was seen in 84% (p < 0.01 vs historic controls), with a mean z-score of 4.3 (95% CI 3.5 to 5.1). There was no difference between those with IPAH, z = 3.6 (95% CI 2.5 to 4.6), and those without, z = 4.7 (95% CI 3.6 to 5.8). Mechanical dyssynchrony was seen in 76% of patients (mean DI = 66 ± 47 vs 18 ± 8 milliseconds in historic controls, p < 0.01) in both IPAH and non-IPAH patients. Post-operative congenital heart disease patients had the largest dyssynchrony index. No correlation was found among electrical or mechanical dyssynchrony, hemodynamics or disease severity. Significant electrical and mechanical dyssynchrony is present in pediatric PH patients, regardless of etiology. The overall effect of electrical and mechanical dyssynchrony on outcomes in this patient population is still unknown. Select patients may benefit from resynchronization therapy.

Catheter Ablation of the Patients with Postsurgical Congenital Heart Diseases

Background: Arrhythmias became one of the most interests among long time survivor of postoperative congenital heart disease patients (poCHD). Methods: We reviewed the result of RFCA for tachyarrhythmias in patients with poCHD from 1998 to 2011. Twenty-six patients (males:females=16:10, mean age 14.3± yearswere enrolled in this study. Result: The arrhythmias for RFCA were, 16 with atrial tachycardia, 8 with atrial flutter, 7 with ventricular tachycardia, 2 with atrio-ventricular reentrant tachycardia, 4 with intraatrial reentrant tachycardia. Between these 26 patients, 33 sessions were performed for 37 lesions, and 29 lesions (78%) were successfully ablated. Overall mean radiation time is 55.5 minutes and mean radiation dose was 136.8 mGy. Conclusion: The success rate of RFCA with poCHD is lower than without CHD, because of complex reentry circuit and multiple tachyarrhythmia mechanism. To improve the success rate of them, development of instant mapping system with the use of thin catheter should be necessary.

Catheter Ablation of Primary Supraventricular Tachycardia Substrate Presenting as Atrial Fibrillation in Adolescents

Atrial fibrillation is rarely encountered in children and adolescents, and these cases are usually secondary to myocardial diseases, electrical abnormalities, or scar related in postoperative congenital heart disease patients. Untreated sustained atrial fibrillation may lead to tachycardia-induced cardiomyopathy and/or systemic thromboembolization. The objective here is to describe our findings in four adolescent patients presenting with recurrent atrial fibrillation. We report here the results of the findings in four patients who presented with recurrent clinical atrial fibrillation. Each of the four underwent electrophysiologic study that revealed a primary reentry or automatic supraventricular tachycardia (SVT) substrate, which was able to be treated with radiofrequency ablation. In three of the four cases, elimination of the primary substrate prevented subsequent recurrence of SVT symptoms or documented SVT and/or atrial fibrillation. Children and adolescents presenting with atrial fibrillation warrant an exhaustive search for a treatable primary cause of myocardial or electrical disease. If present, a primary SVT substrate may be successfully ablated to prevent recurrence of atrial fibrillation and any associated complications. Pulmonary vein isolation is rarely indicated in adolescents and should be avoided.

Long-term prognostic value of cardiac autonomic nervous activity in postoperative patients with congenital heart disease

BackgroundAbnormal cardiac autonomic nervous activity (CANA) is not uncommon in postoperative patients with congenital heart disease (CHD). Methods and resultsWe attempted to clarify the prognostic value of the CANA variables in postoperative CHD patients and prospectively evaluated the CANA variables in 292 consecutive biventricular and 91 Fontan repair patients. The CANA variables included the heart rate variability, arterial baroreflex sensitivity (BRS), washout ratio of the myocardial metaiodobenzylguanidine scintigraphy, and plasma norepinephrine level. With a follow-up of 10±2years, 98 total events that required hospitalization, including 13 deaths and 48 unscheduled cardiac events (UCEs), occurred. In all the CHD patients, all the CANA indices predicted the total events and UCEs. Of those, the NE level (p=0.0004) and BRS (p=0.0373) predicted the mortality. In a multivariate analysis, the BRS was an independent CANA-predictor for the total events (p=0.007). In the biventricular patients, the plasma NE level, heart rate variability, and BRS predicted the total events and UCEs and the BRS was the only independent CANA-predictor for the total events (p=0.0329). In the Fontan patients, the plasma NE level was the only predictor for the UCEs (p=0.0242) and no other CANA variables were independent predictors of the total events or UCEs. ConclusionsAll CANA variables, especially the BRS, were useful predictors for future clinical events in biventricular CHD patients, whereas no CANA variables, except for the plasma NE level, predicted future clinical events in the Fontan patients.

Percutaneous implantation of pulmonary valves for treatment of right ventricular outflow tract dysfunction: a single-centre experience

Stenosis and/or regurgitation of the right-ventricle-to-pulmonary-artery conduit are common conditions in patients after corrective surgery for congenital heart defects. Percutaneous pulmonary valve implantation was introduced to reduce the number of operations needed during the total lifetime of patients with right-ventricle-to-pulmonary-artery conduits. Between April 2007 and April 2008, six patients with severe stenosis and/or regurgitation of the conduit underwent percutaneous pulmonary valve implantation. Cardiac diagnoses were tetralogy of Fallot (three patients), truncus arteriosus (two patients) and post Ross operation (one patient). The median age was 13 (range 7–21) years. Deployment of percutaneous pulmonary valve implantation was achieved without major complications. Right ventricular systolic pressure and right ventricular outflow tract gradient decreased respectively from 61 to 40 mmHg and 37 to 20 mmHg. Follow-up ranged from–to 16 (mean 11) months. All patients are free from reoperation, and valvular competence has been well maintained. One patient experienced recurrence of the obstruction, which was successfully treated with transcatheter balloon dilatation 9 months after the implant. This small study confirms Professor Bonhoeffer's findings that percutaneous pulmonary valve implantation is a safe and feasible treatment that allows the avoidance of surgery in postoperative congenital heart disease patients with a dysfunctioning right-ventricle-to-pulmonary-artery conduits.

Methods to access the surgically excluded cavotricuspid isthmus for complete ablation of typical atrial flutter in patients with congenital heart defects

Cavotricuspid isthmus (CVTI)-dependent flutter in postoperative congenital heart disease patients is common and difficult to treat. The purpose of this study was to evaluate techniques for accessing excluded portions of the CVTI after Fontan or atrial switch procedures and completely ablating flutter. Patients who had undergone Fontan or atrial switch procedures and had CVTI-dependent flutter requiring ablation between 1990 and 2007 were identified. Flutters induced, methods for accessing the CVTI, use of intracardiac echocardiography, complications, and success rates were noted. Sixteen patients (44% males, mean age at ablation 28 years) were identified: 14 prior Fontan and 2 Mustard repair, with a total of 19 ablation procedures. In 13 (81%) of 16 patients, access to the entire CVTI could not be achieved via a systemic venous route. The excluded CVTI was accessed by retrograde transaortic approach in 6 and by anterograde transconduit puncture in 1 patient, with termination and lack of reinducibility of CVTI-dependent flutter achieved in all cases. One patient developed high-grade AV block requiring pacemaker therapy. Follow-up data (range 1-89 months, mean 29 months) were available for 18 of 19 procedures. CVTI atrial flutter recurred in 1 of 7 patients involving access to the pulmonary venous side. Even when surgical procedures exclude a portion of the CVTI, complete ablation of "typical" atrial flutter, including documentation of bidirectional block, can be achieved by novel approaches targeting the surgically excluded arrhythmogenic atrial tissue.

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

Abnormal exercise-related heart rate (HR) dynamics, that is, blunted exercise HR response, lower peak HR, and delayed HR recovery after exercise, are associated with high morbidity and mortality in adults with acquired and congenital heart disease (CHD). However, the precise mechanisms underlying the abnormal HR dynamics remain unclear. The purpose of this study is to evaluate the precise contribution of cardiac autonomic nervous activity (CANA) and sinus node function on exercise-related HR dynamics in postoperative patients with CHD. We analyzed our previous data in 53 postoperative patients with CHD who had undergone pharmacologic evaluation, including intrinsic HR, and compared the results with HR dynamics. Intrinsic HR (84% +/- 11%) was lower than the expected value and independently correlated with resting HR (P < .05). Univariate analysis demonstrated that all CANA indices significantly correlated with most HR dynamic parameters. On multivariate analysis, basal parasympathetic nervous activity significantly influenced all HR dynamics (P < .05-.0001), except for peak HR, whereas postsynaptic beta sensitivity of the sinus node significantly influenced all HR dynamics (P < .05-.001), except for early HR recovery. Resting plasma norepinephrine significantly correlated with all HR dynamics (P < .05-.001), except for resting HR. Lower resting and peak HRs are independently associated with intrinsic sinus node dysfunction and abnormal sympathetic CANA, respectively. A blunted HR increase and delayed early HR recovery are independently associated with impaired sympathetic and parasympathetic CANAs with the greater influence on a blunted exercise HR increase.