Atrial switch operation: past, present, and future

The internal jugular approach for baffle puncture and ablation of atrial arrhythmias in patients with atrial switch procedures: a retrospective analysis

BACKGROUND

Patients with transposition of the great arteries (TGA) who undergo atrial switch procedures may develop symptomatic atrial arrhythmias necessitating ablation. We present a single-centre retrospective analysis of a novel approach using jugular access for catheter ablation in this unique patient population.

METHODS

A 5-year retrospective analysis was conducted on patients referred for atrial arrhythmia ablation following atrial switch procedures. Procedures were performed by experienced operators, and data on patient demographics, procedural characteristics, and outcomes were collected. Statistical analysis was performed to compare outcomes between jugular and femoral access groups.

RESULTS

Jugular access (N = 9) and femoral access (N = 13) cohorts were comparable in age, gender distribution, and clinical characteristics. Procedural success rates were high in both groups, with no significant difference in recurrence rates. Jugular access demonstrated a comparatively safe profile compared to femoral access.

DISCUSSION

The jugular approach offers a viable alternative to femoral access for atrial arrhythmia ablation in patients with atrial switch procedures. The trajectory from the internal jugular vein to the baffle is straightforward, reducing vascular complications. Success rates and procedural times were comparable, highlighting the feasibility and safety of the jugular approach. The option for rapid post-procedural mobilisation adds to its appeal.

CONCLUSION

Atrial arrhythmia ablation with jugular access in patients with atrial switch procedures is safe and effective, providing an alternative in cases where femoral access may pose challenges. This approach warrants consideration in the management of atrial arrhythmias in this unique patient population.

The Role of Speckle-Tracking Echocardiography in Predicting Mortality and Morbidity in Patients With Congenital Heart Disease: A Systematic Review and Meta-analysis

BACKGROUND

Speckle-tracking echocardiography (STE) is now routinely included in cardiac evaluations, but its role in predicting mortality and morbidity in congenital heart disease (CHD) is not well described. We conducted a systematic review to evaluate the prognostic value of STE in patients with CHD.

METHODS

The EMBASE, Medline, Web of Science, Scopus, and Cochrane Central Register of Controlled Trials (CENTRAL) databases were searched from inception to January 2023 for terms related to all CHD, STE, and prognosis. Meta-analysis of association of right ventricle and left ventricle strain (RV Sl and LV Sl, respectively) with major adverse cardiovascular events (MACEs) was performed in atrial switch transposition of the great arteries (asTGA)/congenitally corrected TGA (ccTGA), tetralogy of Fallot (ToF), and congenital aortic stenosis (cAS)/bicuspid aortic valve (BAV). P-value combination analysis was additionally performed for all CHD groups.

RESULTS

A total of 33 studies (30 cohorts, n = 8,619 patients, children, and adults) were included. Meta-analysis showed the following parameters as being associated with MACE: RV Sl in asTGA/ccTGA (hazard ratio [HR] = 1.1/%; CI, [1.03; 1.18]), RV Sl and LV Sl in ToF (HR = 1.14/%; CI, [1.03; 1.26] and HR = 1.14/%; CI, [1.08; 1.2], respectively), and LV Sl in cAS/BAV (HR = 1.19/%; CI, [1.15; 1.23]). The RV Sl and strain rate were associated with outcomes also in single ventricle/hypoplastic left heart syndrome (at all palliation stages except before Norwood stage 1) and LV Sl in Ebstein's anomaly.

CONCLUSIONS

This systematic review and meta-analysis showed that biventricular strain and strain rate were associated with outcomes in a variety of CHD, highlighting the need for updated recommendations on the use of STE in the current guidelines, specific to disease types.

Echocardiographic differences between D-TGA and L-TGA in adult patients

Transposition of the great arteries (TGA) is a common cardiac malformation in which the great arteries are discordant relative to the ventricles. The two common forms of transposition include D-TGA, which presents with cyanosis early in life, and L-TGA, which on the other hand, may permit survival to adulthood without being diagnosed in childhood. There are remarkable differences between these two forms of TGA in the clinical presentation, echocardiographic findings, and long-term outcomes. Multimodality imaging in patients with TGA usually provides diagnostic and hemodynamic assessment for routine follow-up and preoperative planning prior to surgical or transcatheter intervention. In this review, we present a summary of the fundamental echocardiographic aspects of these two forms of TGA with emphasis in the adult congenital heart disease population.

Intracardiac Echocardiography to Guide Mapping and Ablation of Arrhythmias in Patients with Congenital Heart Disease

Catheter ablation of arrhythmias in congenital heart disease can be a challenging undertaking with often complicated anatomic considerations. Understanding this anatomy and the prior surgical repairs is key to procedural planning and a successful outcome. Intracardiac echocardiography (ICE) adds complimentary real-time visualization of anatomy and catheter positioning along with other imaging modalities. In addition, ICE can visualize suture lines, baffles, and conduits from repaired congenital heart disease and forms a useful part of the toolkit required to deal with these complex arrhythmias.

Left Atrial Volumetric and Deformation Analysis in Adult Patients with Dextro-Transposition of the Great Arteries (Insights from the CSONGRAD Registry and MAGYAR-Path Study)

Background: In complete or dextro-transposition of the great arteries (dTGA), the aorta and the pulmonary artery are transposed. The present study was designed to examine dTGA-associated left atrial (LA) volumetric and functional abnormalities in adult patients late after repair and to compare their results to those of healthy controls. Methods: The present study consisted of 15 dTGA patients (30.3 ± 8.1 years, 9 males), the patients had Mustard (n = 8) or Senning (n = 7) procedure performed. Their results were compared to those of 36 age- and gender-matched healthy subjects (28.7 ± 1.5 years, 24 males). Results: Increased maximum LA volume and reduced LA emptying fractions respecting the cardiac cycle could be demonstrated in our dTGA patients. LA stroke volumes representing all LA functions were significantly reduced. Peak LA circumferential, longitudinal, and area strains and LA circumferential, longitudinal, and area strains measured at atrial contraction were reduced in our dTGA patients. Most LA strains were reduced in patients having Mustard surgery compared to controls and patients undergoing Senning operation. Conclusions: Significant LA volumetric and functional abnormalities could be demonstrated in adult patients with dTGA late after repair. Senning procedure seems to have more beneficial long-term effects on LA volumetric and functional features as compared to the Mustard procedure.

NFC Powered Implantable Temperature Sensor

Inductively powered 99% accurate implantable temperature sensor is designed, characterized and the findings are presented in this paper. The implantable sensors deliver a continuous temperature reading to external storage or readout devices via Near Field Communication interface. A 2.76μH rectangular inductive coil printed on a thin biocompatible plastic substrate is designed to establish the coupling link through NFC interface with external readout devices. A commercially available wide range temperature sensor chip is mounted along with the developed inductive coil on the same plastic substrate. For 50 samples, the received signal strength indicator, temperature accuracy and statistical distribution of measurement levels is investigated. Comparison of predetermined temperature in a controlled temperature and humidity chamber versus the temperature reading from the developed sensors proves a 99% accuracy.

Echocardiography vs cardiac magnetic resonance imaging assessment of the systemic right ventricle for patients with d-transposition of the great arteries status post atrial switch

OBJECTIVE

Patients with Dextro-transposition of the great arteries status post atrial switch (dTGA s/p atrial switch) are "at-risk" for systemic right ventricular (RV) dysfunction. Due to complex RV geometry, echocardiography (Echo) does not allow accurate determination of ejection fraction (EF), but cardiac magnetic resonance imaging (CMR) allows quantitative right ventricular assessment. Measures of ventricular deformation may be precursors to global ventricular dysfunction. The primary aim of this study was to characterize imaging and clinical findings for adult patients with dTGA s/p atrial switch.

DESIGN

This was a retrospective cohort study of patients with dTGA s/p atrial switch operation (February 1966 to August 1988) with CMR performed at Children's Hospital of Wisconsin (from September 2005 to May 2015). Eligible patients had clinic visit, Echo, and exercise stress test within 1 year of CMR.

RESULTS

This study enrolled twenty-seven patients (16 males, 11 females) with dTGA s/p atrial switch (18 with Mustard operation and 9 with Senning operation; median age 30 years; 74% New York Heart Association class 1 and 26% class 2). Seventy-four percentage had normal RV systolic function (RV EF >45% by CMR). No correlation was observed between Echo strain data and clinical status (EF, exercise endurance, VO₂ max, or New York Heart Association class). Cardiac magnetic resonance imaging RV global circumferential strain GCS and RV EF had moderate negative correlation (r = -0.65, P < .001). Global circumferential strain was significantly different for those with RV EF above and below 45%, while global peak longitudinal strain (GLS) was not. Patients had reduced CMR myocardial strain values compared with healthy controls.

CONCLUSIONS

Reduced RV CMR GCS (for those with RV EF <45%) suggests that CMR evaluation may enhance early detection of detrimental changes in the systemic RV myocardium.

Exploring the Prognostic Value of Novel Markers in Adults With a Systemic Right Ventricle

Background Adults with a systemic right ventricle (sRV) have a high risk of cardiac complications. This study aimed to identify prognostic markers in adults with sRV based on clinical evaluation, echocardiography, and blood biomarkers. Methods and Results In this prospective cohort study, consecutive clinically stable adults with sRV caused by Mustard- or congenitally corrected transposition of the great arteries were included (2011-2013). Eighty-six patients were included (age 37±9 years, 65% male, 83% New York Heart Association functional class I, 76% Mustard transposition of the great arteries, 24% congenitally corrected transposition of the great arteries). Venous blood sampling was performed including N-terminal pro B-type natriuretic peptide, high-sensitive-troponin-T, high-sensitivity C-reactive protein, growth differentiation factor-15, galectin-3, red cell distribution width, estimated glomerular filtration rate, and hemoglobin. Besides conventional echocardiographic measurements, longitudinal, circumferential, and radial strain were assessed using strain analysis. During a median follow-up of 5.9 (interquartile range 5.3-6.3) years, 19 (22%) patients died or had heart failure (primary end point) and 29 (34%) patients died or had arrhythmia (secondary end point). Univariable Cox regression analysis was performed using dichotomous or standardized continuous variables. New York Heart Association functional class >I, systolic blood pressure, and most blood biomarkers were associated with the primary and secondary end point (galectin-3 not for primary, N-terminal pro B-type natriuretic peptide and high-sensitivity C-reactive protein not for secondary end point). Growth differentiation factor-15 showed the strongest association with both end points (hazard ratios; 2.44 [95% CI 1.67-3.57, P<0.001], 2.00 [95% CI 1.46-2.73, P<0.001], respectively). End-diastolic basal dimension of the subpulmonary ventricle was associated with both end points (hazard ratio: 1.95 [95% CI 1.34-2.85], P<0.001, 1.70 [95% CI 1.21-2.38, P=0.002], respectively). Concerning strain analysis, only sRV septal strain was associated with the secondary end point (hazard ratio 0.58 [95% CI 0.39-0.86], P=0.006). Conclusions Clinical, conventional echocardiographic, and blood measurements are important markers for risk stratification in adults with a sRV. The value of novel echocardiographic strain analysis seems limited.

The role of echocardiography in the management of adult patients with congenital heart disease following operative treatment

Treatment of congenital heart diseases has significantly advanced over the last few decades. Due to the continuously increasing survival rate, there are more and more adult patients with congenital heart diseases and these patients present at the adult cardiologist from the paediatric cardiology care. The aim of the present review is to demonstrate the role of echocardiography in some significant congenital heart diseases.

Long-term Management of the Arterial Switch Patient

PURPOSE OF REVIEW

This review paper describes the management of patients with dextro-transposition of the great arteries (D-TGA) with a focus on the complications seen and the appropriate care required to identify and prevent adverse events.

RECENT FINDINGS

D-TGA is a form of cyanotic congenital heart disease (CHD) representing ~ 3% of all CHD and almost 20% of all cyanotic CHD. Since the late 1980s, standard of care is to repair these patients with an arterial switch operation (ASO) as opposed to a Mustard/Senning operation. The long-term survival and complication rates are superior in the ASO. Long-term follow-up is recommended for all D-TGA patients and includes management with adult congenital heart disease specialists and the use of echocardiography and advanced imaging with CT or MRI. The most common complications seen are pulmonary stenosis, coronary artery stenosis, and neo-aortic regurgitation. Careful evaluation of new symptoms or declining function is essential in preventing and treating these long-term sequelae.

Left-Sided Reoperations After Arterial Switch Operation: A European Multicenter Study

BACKGROUND

We sought to report the frequency, types, and outcomes of left-sided reoperations (LSRs) after an arterial switch operation (ASO) for patients with D-transposition of the great arteries (D-TGA) and double-outlet right ventricle (DORV) TGA-type.

METHODS

Seventeen centers belonging to the European Congenital Heart Surgeons Association (ECHSA) contributed to data collection. We included 111 patients who underwent LSRs after 7,951 ASOs (1.4%) between January 1975 and December 2010. Original diagnoses included D-TGA (n = 99) and DORV TGA-type (n = 12). Main indications for LSR were neoaortic valve insufficiency (n = 52 [47%]) and coronary artery problems (CAPs) (n = 21 [19%]).

RESULTS

Median age at reoperation was 8.2 years (interquartile range [IQR], 2.9-14 years). Seven patients died early after LSRs (6.3%); 4 patients with D-TGA (5.9%) and 3 patients with DORV TGA-type (25%) (p = 0.02). Median age at last follow-up was 16.1 years (IQR, 9.9-21.8 years). Seventeen patients (16%) required another reoperation, which was more frequent in patients with DORV- TGA type (4 of 9 [45%]) than in patients with D-TGA (13 of 95 [14%]). Late death occurred in 4 patients (4 of 104 [3.8%]). The majority of survivors were asymptomatic at last clinical examination (84 of 100 [84%]).

CONCLUSIONS

Reoperations for residual LSRs are infrequent but may become necessary late after an ASO, predominantly for neoaortic valve insufficiency and CAPs. Risk at reoperation is not negligible, and DORV TGA-type anatomy, as well as procedures on the coronary arteries, were significantly associated with a higher morbidity and a lower overall survival. Recurrent reoperations after LSRs may be required.

Venous Diversion Surgery Revisited: A Baffling Situation

With the increasing number of survivors with congenital heart disease (CHD) reaching adulthood, it is important for the clinician to be familiar with the various surgical options performed in this growing patient population. We describe the case of a 65-year-old female who presented with hypoxia and right-to-left shunting following a surgical repair of an atrial septal defect (ASD) secundum and anomalous pulmonary veins with a partial atrial diversion procedure in childhood. The use of multimodality cardiovascular imaging using echocardiography, computed tomography, magnetic resonance imaging, and invasive cardiac catheterization was complementary in the preoperative diagnosis and management of this unique baffling situation.

Imaging the adult with transposition of the great arteries

PURPOSE OF REVIEW

Patients with complete and congenitally corrected transposition of the great arteries commonly survive into adulthood and present with a vast array of clinical residua.

RECENT FINDINGS

Echocardiography remains the primary imaging modality in the routine assessment of the adult with transposition of the great arteries. It provides a comprehensive anatomic and hemodynamic evaluation. Limitations to echocardiography include evaluation of the following: the systemic right ventricle, baffle patency following atrial switch procedure, coronary arteries following arterial switch procedure or Nikadoh, and multilevel right ventricular outflow tract obstruction.

SUMMARY

Each form of palliation for transposition of the great arteries results in unique long-term sequelae that affect outcomes. A multimodality approach to imaging is required for a complete evaluation.

Modified Warden Procedure Using the Concept of Senning Operation: Repair Without Any Patch

Various surgical techniques have been proposed to repair a partial anomalous pulmonary venous connection to the superior vena cava, such as the single-patch, the double-patch, and the caval division (Warden) techniques. The limited growth potential of the artificial patch, stenosis of the cavoatrial channel or rerouted pulmonary vein channel, and the risk of sinus node dysfunction were possible adverse events. We here describe a modified Warden procedure without any patch in a 6-month-old infant. Using the concept of the Senning atrial switch technique, the interatrial septum and the free wall of the right atrium were used to baffle the anomalous pulmonary vein into the left atrium.

Palliative Senning in the Treatment of Congenital Heart Disease with Severe Pulmonary Hypertension

BACKGROUND

Transposition of the great arteries (TGA) is the most common cyanotic cardiopathy, with an incidence ranging between 0.2 and 0.4 per 1000 live births. Many patients not treated in the first few months of life may progress with severe pulmonary vascular disease. Treatment of these patients may include palliative surgery to redirect the flow at the atrial level.

OBJECTIVE

Report our institutional experience with the palliative Senning procedure in children diagnosed with TGA and double outlet right ventricle with severe pulmonary vascular disease, and to evaluate the early and late clinical progression of the palliative Senning procedure.

METHODS

Retrospective study based on the evaluation of medical records in the period of 1991 to 2014. Only patients without an indication for definitive surgical treatment of the cardiopathy due to elevated pulmonary pressure were included.

RESULTS

After one year of follow-up there was a mean increase in arterial oxygen saturation from 62.1% to 92.5% and a mean decrease in hematocrit from 49.4% to 36.3%. Lung histological analysis was feasible in 16 patients. In 8 patients, pulmonary biopsy grades 3 and 4 were evidenced.

CONCLUSION

The palliative Senning procedure improved arterial oxygen saturation, reduced polycythemia, and provided a better quality of life for patients with TGA with ventricular septal defect, severe pulmonary hypertension, and poor prognosis.

Persistent Pulmonary Hypertension in a Neonate With Transposition of Great Arteries and Intact Ventricular Septum

Transposition of the great arteries (TGA) with intact ventricular septum (IVS) has very favorable short- and long-term surgical outcome. Although rare, when associated with persistent pulmonary hypertension (PPH), it exhibits significant mortality risk and management challenges. We report the case of a neonate with TGA with IVS and PPH who underwent successful early surgical repair with emphasis on clinical management and review of the literature.

Surgery for transposition of great arteries: A historical perspective

The history of surgery for transposition of great arteries (TGA) has paralleled the history of cardiac surgery. In fact, it began before the birth of open heart surgery when the palliative Blalock–Hanlon septectomy was first performed in 1948. The atrial switch, which was an attempt to correct the physiology of transposition, had significant shortcomings. The arterial switch sought to address them. This has emerged as an anatomically as well as physiologically appropriate solution. Today we continue to pursue technical refinements as well as try to expand the indications of the arterial switch. This review traces the various milestones in this perpetual journey.

Mid-term morbidity and mortality of patients after arterial switch operation in infancy for transposition of the great arteries

INTRODUCTION AND OBJECTIVES

The arterial switch operation is currently the preferred surgical approach for complete transposition of the great arteries. We sought to determine the mid-term results of this intervention.

METHODS

A single-institution retrospective review of clinical records of all consecutive patients who underwent the arterial switch surgery between 1985 and 2010.

RESULTS

Overall, the operation was performed on 155 patients (68% boys) at a median age of 13 days: 64% with an intact septum, 46% with a ventricular septal defect, and 4.5% with associated aortic arch anomaly. The usual coronary pattern was found in 63%. Palliative surgery was performed prior to arterial switch in 6.5%. In all, 137 perioperative survivors were followed for a median of 6 years. Late mortality was 2.9%, of which 50% was due to coronary complications. Eighteen percent required surgical and/or percutaneous reintervention: 95.6% for right-sided obstruction and 4.3% for aortic regurgitation. At last follow-up, 92% had functional class I symptoms and 95% were free of arrhythmias. The left ventricular ejection fraction was greater than 55% in 95%, 28% had neoaortic regurgitation (78% mild regurgitation), and 31% had right ventricular outflow tract obstruction with a mean gradient according to echocardiography greater than 25mmHg.

CONCLUSIONS

Mid-term survival of patients after arterial switch operation is excellent and their functional status is good. However, a few patients have residual lesions and a need for further intervention during follow-up, mostly for right-sided obstructions. Late mortality was uncommon and was related to coronary complications. Neoaortic root dilation and regurgitation are not major issues in early adulthood, but the long-term course of these lesions is still unknown.

Revisiting the Baffes operation: its role in transposition of the great arteries

Thomas Baffes developed one of the first operations for transposition of the great arteries directing inferior vena cava flow to the left atrium using an interposed homograft in the era before open heart surgery. He performed 117 Baffes operations from 1953 to 1960, with 30% overall mortality, and an additional 85 Baffes procedures before 1968, allowing many to survive until the atrial baffle operations. During the early days before hospitals had cardiopulmonary bypass machines, Tom Baffes and colleagues purchased a heart-lung machine and transported it to various Chicago hospitals to treat patients and stimulate interest in this emerging technology.

Long-term follow-up assessment after the arterial switch operation for correction of dextro-transposition of the great arteries by means of exercise myocardial perfusion-gated SPECT

The arterial switch operation (ASO) is the preferred technique for correcting transposition of the great arteries, but translocation and reimplantation of the coronary arteries can produce myocardial ischemia. This report aims to describe the authors' experience with exercise single-photon emission computed tomography (SPECT) used to evaluate myocardial perfusion. Exercise-rest gated-myocardial perfusion SPECT was performed for 69 patients (49 boys; median age, 9 years; 5th percentile [6.4 years] to 95th percentile [15.6 years]), 64 of whom were asymptomatic 9.98 ± 3.20 years after ASO. During exercise testing, the patients reached 9.85 ± 3.05 metabolic equivalents (METs) and a median heart rate of 160 beats per minute (bpm), 5th percentile (106 bpm) to 95th percentile (196 bpm). Whereas 61 patients (88.41 %) had normal myocardial perfusion, 2 patients (2.9 %) had reversible defects, and 6 patients (8.7 %) had fixed defects. All the patients with perioperative ischemic complications (4/4, 100 %) had myocardial perfusion defects, whereas four patients (4/65, 6.15 %) without ischemic complications had abnormal perfusion (p = 0.0005). Age at the time of surgery did not differ significantly (p = 0.234) between the patients with perfusion defects and those with normal study results. No significant difference was observed between the patients who had an A coronary pattern (left coronary artery originating from the left sinus and the right coronary artery originating from the right sinus, n = 47) and those who had a non-A coronary pattern (n = 22) (p = 1). The high rate for normality of exercise myocardial perfusion in our study suggests that myocardial perfusion gated-SPECT should be reserved for patients who have experienced perioperative ischemic complications or those with symptoms, at least during the first 10 years after the surgery.

Adolescents with d-transposition of the great arteries corrected with the arterial switch procedure: neuropsychological assessment and structural brain imaging

BACKGROUND

We report neuropsychological and structural brain imaging assessments in children 16 years of age with d-transposition of the great arteries who underwent the arterial switch operation as infants. Children were randomly assigned to a vital organ support method, deep hypothermia with either total circulatory arrest or continuous low-flow cardiopulmonary bypass.

METHODS AND RESULTS

Of 159 eligible adolescents, 139 (87%) participated. Academic achievement, memory, executive functions, visual-spatial skills, attention, and social cognition were assessed. Few significant treatment group differences were found. The occurrence of seizures in the postoperative period was the medical variable most consistently related to worse outcomes. The scores of both treatment groups tended to be lower than those of the test normative populations, with substantial proportions scoring ≥1 SDs below the expected mean. Although the test scores of most adolescents in this trial cohort are in the average range, a substantial proportion have received remedial academic or behavioral services (65%). Magnetic resonance imaging abnormalities were more frequent in the d-transposition of the great arteries group (33%) than in a referent group (4%).

CONCLUSIONS

Adolescents with d-transposition of the great arteries who have undergone the arterial switch operation are at increased neurodevelopmental risk. These data suggest that children with congenital heart disease may benefit from ongoing surveillance to identify emerging difficulties.

CLINICAL TRIAL REGISTRATION

URL: http://www.clinicaltrials.gov. Unique identifier: NCT00000470.

Reversal of fortune: surgical management of transposition in the pre-arterial switch era

The development of operations for transposition of the great arteries (TGA) culminating in the eventual success of the arterial switch operation (ASO) remains one of the most intriguing demonstrations of ingenuity in the history of cardiac surgery. Very early attempts at switching the great arteries were daring but unsuccessful. This early lack of success with the ASO proved daunting, and yielded to "venous" switches, with increasing success. These venous switches evolved into the atrial baffle procedures, which began in the first golden age of TGA surgery of the 1960s and 1970s. The continued quest for an anatomic correction resulted in other clever operations before the modern era of the ASO.

Treatment options for transposition of the great arteries with ventricular septal defect complicated by pulmonary vascular obstructive disease

The arterial switch operation is the procedure of choice for patients with isolated transposition of the great arteries or those with associated atrial and/or ventricular septal defects. After the development of pulmonary arterial hypertension, the surgical options for patients with a late presentation include either retraining the left ventricle by pulmonary artery banding followed by an arterial switch operation or palliative atrial or arterial switch, with or without medical management of pulmonary hypertension. We present a case with D-transposition of the great arteries with ventricular septal defects and irreversible pulmonary arterial hypertension who improved after a palliative atrial switch operation.

Long-term functional outcome of patients following the mustard procedure: the next decade of follow-up

BACKGROUND

Nearly 10 years ago, we studied a population of patients with d-transposition of the great arteries (DTGA) who had undergone the Mustard procedure 8-26 years earlier. The present study was undertaken to determine how that cohort of patients is currently functioning.

METHODS

Of the 45 original patients, 44 were located. Six (13%) had either died (n = 4) or received a cardiac transplant (n = 2). In total, 35 of the remaining 38 patients (78%) chose to undergo testing. Systemic right ventricular ejection fraction (RVEF) was estimated using radionuclide angiocardiography. Exercise stress testing, echocardiography, Holter monitoring, and a quality of life questionnaire were also performed.

RESULTS

Those 6 that died or received cardiac transplantation did so between 16 and 25 years of age. The surviving participants ranged in age from 19 to 37 years. Peak oxygen consumption was significantly diminished at 27.7 +/- 6.9 mL/kg/min. Comparison of exercise duration from the original study demonstrated a significant decrease (11.2 +/- 2.2 minutes to 9.1 +/- 2.9 minutes) (P < 0.001). Comparison of RVEF data from the original study did not demonstrate a significant decrease (0.54 +/- 0.10 to 0.53 +/- 0.10) (P = 0.27). Quality of life data suggested that Mustard patients do not score as well in physical functioning, general health, and level of energy as normal adults, but are comparable with adult patients with other chronic diseases. Mustard patients are similar to normal adults and feel better than other adults with chronic illness in their interpretation of social functioning and bodily pain.

CONCLUSION

Cardiac mortality of 13% occurred during the second and third decade of life in this cohort of patients with DTGA palliated by the Mustard procedure. Despite continuing deterioration in exercise performance, right ventricular function, and cardiac rhythm, many surviving patients with DTGA continue to lead normal lives into the 4th decade after Mustard procedure.

Adaptation of baroreflex function to increased carotid artery stiffening in patients with transposition of great arteries

We have shown previously that TGA (transposition of great arteries) is associated with increased carotid artery stiffness. It has been established that stiffening of the barosensory vessel wall results in reduced baroreceptor activation and impaired BRS (baroreflex sensitivity). In the present study we tested the hypothesis that the increased carotid artery stiffness in TGA patients was associated with reduced cardiovagal BRS. We studied 32 TGA patients aged 9–19 years, 12±3 years after surgical repair and 32 age-matched healthy control subjects. Carotid artery diastolic diameter and pulsatile distension was determined by echo wall tracking; carotid blood pressure was measured by tonometry. BRS was measured using spontaneous techniques [BRSseq and LFgain (low-frequency transfer function gain)] and by the phenylephrine method (BRSphe). Carotid artery distensibility was markedly reduced in patients as compared with controls (5.6±1.9×10−3 compared with 8.7±2.7×10−3/mmHg P<0.05, as determined using an unpaired Student's t test), but BRS was not different in patients and controls (20.3±14.7 compared with 21.7±12.7 for BRSseq; 13.1±9.2 compared with 10.6±4.5 for LFgain; and 19.1±8.6 compared with 24.8±7.2 for BRSphe respectively). Carotid artery elastic function was markedly impaired in patients with TGA, but the increased stiffness of the barosensory vessel wall was not associated with reduced BRS. It appears that attenuation of baroreceptor stimulus due to arterial stiffening may be compensated by other, possibly neural, mechanisms when it exists as a congenital abnormality.

Is the arterial switch operation as good over the long term as we thought it would be?

Surgical intervention for hearts with transposition, defined as concordant atrioventricular and discordant ventriculo-arterial connections, has been one of the landmark achievements in the field of paediatric cardiac surgery. In the early 1950s, pioneer surgeons attempted to palliate patients with transposed arterial trunks with an early form of the arterial switch operation. As a result of initially dismal outcomes secondary to difficulties with coronary arterial transfer, the unprepared nature of the morphologically left ventricle, and primitive methods for cardiopulmonary bypass, the arterial switch was abandoned in favour of several procedures achieving correction at atrial and venous levels, culminating in the Mustard and Senning operations.1,2These innovative procedures produced the earliest surviving children with transposition. Although the atrial switch procedures achieved widespread acceptance and success during the mid-1960s through the mid-1980s, the search for an operation to return the great arteries to their normal anatomic positions continued. This pursuit was stimulated primarily by the accumulating observations in mid-to-late term follow up studies of: an increasing frequency of important arrhythmic complications, including sinus nodal dysfunction, atrial arrhythmias, and sudden, unexplained death, by the development of late right ventricular dysfunction and significant tricuspid regurgitation in a ventricle potentially unsuited for a lifetime of systemic function by a small but important prevalence of obstruction of the systemic and/or pulmonary venous pathways, and by dissatisfaction with the operative mortality in the subgroup of infants complicated by additional presence of a large ventricular septal defect.3–6As we have already discussed, a number of novel procedures to achieve anatomic correction had been described as early as 1954, but clinical success was not accomplished until 1975, when Jatene and co-workers7astounded the world of paediatric cardiology with their initial description.