Experiences and Attitudes Toward Telemedicine in an Adult Congenital Heart Disease Clinic: Lessons Learned from the COVID-19 Pandemic.

The coronavirus disease 2019 (COVID-19) pandemic has driven a broader adoption of telemedicine (TM). We aim to describe adult congenital heart disease (ACHD) patient experiences with TM and explore factors associated with positive attitude toward future TM visits. This is a cross-sectional, single-center study in an outpatient ACHD clinic from February to June, 2022. Between-group comparisons were made using Wilcoxon-Rank Sum, Chi-Square, or Fisher-Exact tests. Univariate logistic regression was performed for variables that could correlate with a "positive" attitude toward future TM visits. Significance was determined using an alpha level of 0.05. Of 262 patients (median age 33 years, 55% female, 81% White), 115 (44%) had a prior TM visit and 110 (96%) reported a positive experience. There were 64 (24%) with a positive attitude toward future TM visits. Concerns include lack of cardiac testing and limited quality of visit. Patients with visits every 3-6 months (Odds Ratio [OR] 2.44; p < 0.01) and prior TM visit (OR 1.89; p = 0.03) had higher odds of a positive attitude toward future TM, whereas males had lower odds (OR 0.53; p = 0.04). Age, annual income, disease complexity, distance from clinic, and employment status were not associated. There is high rate of satisfaction with TM among ACHD patients but only one-quarter indicated interest in using TM in the future. Factors associated with interest in TM visits are identified, and together with patient feedback, can be used to understand potential role of TM for the ACHD population in the post-pandemic era.

Introduction of transcatheter edge-to-edge repair in patients with congenital heart disease at a children's hospital.

BACKGROUND: Atrioventricular valve regurgitation (AVVR) is a devastating complication in children and young adults with congenital heart disease (CHD), particularly in patients with single ventricle physiology. Transcatheter edge-to-edge repair (TEER) is a rapidly expanding, minimally invasive option for the treatment of AVVR in adults that avoids the morbidity and mortality associated with open heart surgery. However, application of TEER in in CHD and in children is quite novel. We describe the development of a peri-procedural protocol including image-derived pre-intervention simulation, with successful application to four patients. AIMS: To describe the initial experience using the MitraClip system for TEER of dysfunctional systemic atrioventricular valves in patients with congential heart disease within a pediatric hospital. METHODS: A standardized screening and planning process was developed using cardiac magnetic resonance imaging, three dimensional echocardiography and both virtual and physical simulation. Procedures were performed using the MitraClip G4 system and patients were clinically followed post-intervention. RESULTS: A series of four CHD patients with at least severe AVVR were screened for suitability for TEER with the MitraClip system: three patients had single ventricle physiology and Fontan palliation, and one had repair of a common atrioventricular canal defect. Each patient had at least severe systemic AVVR and was considered at prohibitively high risk for surgical repair. Each patient underwent a standardized preprocedural screening protocol and image-derived modeling followed by the TEER procedure with successful clip placement at the intended location in all cases. CONCLUSIONS: The early results of our protocolized efforts to introduce TEER repair of severe AV valve regurgitation with MitraClip into the CHD population within our institution are encouraging. Further investigations of the use of TEER in this challenging population are warranted.

Successful in vitro fertilization in women with Fontan physiology.

PURPOSE: Patients with single ventricle anatomy palliated with Fontan operation are at risk for thromboembolism, arrhythmia, and heart failure rendering pregnancy high risk or even contraindicated. Infertility and high rates of first trimester miscarriage are not uncommon. In vitro fertilization (IVF) with or without gestational surrogacy can be an option, but poses risks during ovarian stimulation, oocyte retrieval, and the post-procedural period. We present six cases of women with complex congenital heart disease status post Fontan operation who underwent successful IVF. METHODS: Case series from a single-center tertiary care setting. RESULTS: Indications for referral were cardiac or fertility concerns for pregnancy of the congenital cardiologist. One woman had mild volume overload after oocyte retrieval requiring furosemide and one experienced post-operative colitis. There were no thrombotic complications. CONCLUSIONS: A multidisciplinary team-based approach can result in successful oocyte retrieval and IVF in women with complex congenital heart disease and Fontan physiology.

Improvement in ventricular function with rhythm control of atrial arrhythmias may delay the need for atrioventricular valve surgery in adults with congenital heart disease.

OBJECTIVE: Atrial arrhythmias and atrioventricular valve regurgitation (AVVR) are common causes of morbidity among adults with congenital heart disease (ACHD). The impact of rhythm control on AVVR in this population is unknown. We sought to determine whether a rhythm control strategy is associated with greater freedom from AV valve surgery than a rate control strategy. DESIGN: Patients evaluated by both ACHD and electrophysiology specialists at a single academic center were screened for atrial arrhythmias and at least moderate-severe AVVR. Clinical and electrographic data were abstracted. All echocardiograms were interpreted by a single echocardiographer blinded to treatment strategy. Patients were followed until AV valve surgery, heart transplantation, death, or last clinical follow-up. RESULTS: Rhythm control was attempted in 9 of 24 identified patients. Among these nine patients, arrhythmias were eliminated in three and reduced from persistent to paroxysmal in another three. In the rhythm control group, mean left ventricular ejection fraction improved from 54.4 ± 12.4% to 60.0 ± 11.5% (P = .02) and mean right ventricular systolic function increased nearly one grade (P = .02). AVVR did not decrease significantly. No significant change in left or right ventricular systolic function, or AVVR was observed among the 15 patients treated with rate control. Four-year survival free of AV valve operation and heart transplant was 88% in the rhythm control group and 31% in the rate control group (P = .04). CONCLUSIONS: In ACHD patients with atrial arrhythmias and at least moderate-severe AVVR, a rhythm control strategy was associated with improved biventricular systolic function. This improvement in ventricular function and symptoms may allow valve surgery to be deferred.

Long term follow-up after ventricular tachycardia ablation in patients with congenital heart disease.

BACKGROUND: Ventricular tachycardia (VT) is frequently encountered in patients with repaired and unrepaired congenital heart disease (CHD), causing significant morbidity and sudden cardiac death. Data regarding underlying VT mechanisms and optimal ablation strategies in these patients remain limited. OBJECTIVE: To describe the electrophysiologic mechanisms, ablation strategies, and long-term outcomes in patients with CHD undergoing VT ablation. METHODS: Forty-eight patients (mean age 41.3 ± 13.3 years, 77.1% male) with CHD underwent a total of 57 VT ablation procedures at two centers from 2000 to 2017. Electrophysiologic and follow-up data were analyzed. RESULTS: Of the 77 different VTs induced at initial or repeat ablation, the underlying mechanism in 62 (81.0%) was due to scar-related re-entry; the remaining included four His-Purkinje system-related macrore-entry VTs and focal VTs mainly originating from the outflow tract region (8 of 11, 72.7%). VT-free survival after a single procedure was 72.9% (35 of 48) at a median follow-up of 53 months. VT-free survival after multiple procedures was 85.4% (41 of 48) at a median follow-up of 52 months. There were no major complications. Three patients died during the follow-up period from nonarrhythmic causes, including heart failure and cardiac surgery complication. CONCLUSION: While scar-related re-entry is the most common VT mechanism in patients with CHD, importantly, nonscar-related VT may also be present. In experienced tertiary care centers, ablation of both scar-related and nonscar-related VT in patients with CHD is safe, feasible, and effective over long-term follow-up.

Pulmonary arterial hypertension in adults with systemic right ventricles referred for cardiac transplantation.

BACKGROUND: Systemic right ventricular (RV) failure may progress necessitating referral for orthotropic heart transplantation (OHT). Pulmonary hypertension (PH) frequently coexists in adult congenital heart disease and can complicate the assessment for OHT. METHODS: Single-center case series of six patients (median age 34.9 years [IQR, 31.9-42.4]) with systemic RV physiology with PH referred for OHT evaluation from 2008 to 2017. RESULTS: One-third (n = 6) of 18 patients with systemic RV physiology referred for OHT evaluation had pulmonary arterial hypertension (PAH) defined as mean pulmonary artery pressure (mPAP) > 25 mm Hg and pulmonary vascular resistance (PVR) > 3 Wood Units. Two of the six patients were considered OHT-ineligible due to PH and comorbidities. Of the remaining four, two had pre-capillary PH and underwent heart-lung transplant (HLTx). The other two demonstrated reversibility of PVR with vasodilator testing and underwent OHT alone, one of whom died post-transplant from PH crisis. CONCLUSIONS: Pulmonary arterial hypertension is common in systemic RV patients referred for OHT. Systemic RV dysfunction places these patients at risk for post-capillary PH but pre-capillary PH can exist. Despite management with selective pulmonary vasodilators and afterload reduction, criteria for listing patients for HLTx vs OHT are not known and need further elucidation.

Accuracy of risk prediction scores in pregnant women with congenital heart disease.

OBJECTIVE: To assess performance of risk stratification schemes in predicting adverse cardiac outcomes in pregnant women with congenital heart disease (CHD) and to compare these schemes to clinical factors alone. DESIGN: Single-center retrospective study. SETTING: Tertiary care academic hospital. PATIENTS: Women ≥18 years with International Classification of Diseases, Ninth Revision, Clinical Modification codes indicating CHD who delivered between 1998 and 2014. CARPREG I and ZAHARA risk scores and modified World Health Organization (WHO) criteria were applied to each woman. OUTCOME MEASURES: The primary outcome was defined by ≥1 of the following: arrhythmia, heart failure/pulmonary edema, transient ischemic attack, stroke, dissection, myocardial infarction, cardiac arrest, death during gestation and up to 6 months postpartum. RESULTS: Of 178 women, the most common CHD lesions were congenital aortic stenosis (15.2%), ventricular septal defect (13.5%), atrial septal defect (12.9%), and tetralogy of Fallot (12.9%). Thirty-five women (19.7%) sustained 39 cardiac events. Observed vs expected event rates were 9.9% vs 5% (P = .02) for CARPREG I score 0 and 26.1% vs 7.5% (P < .001) for ZAHARA scores 0.51-1.5. ZAHARA outperformed CARPREG I at predicting adverse cardiovascular outcomes (AUC 0.80 vs 0.72, P = .03) but was not significantly better than modified WHO. Clinical predictors of adverse cardiac event were symptoms (P = .002), systemic ventricular dysfunction (P < .001), and subpulmonary ventricular dysfunction (P = .03) with an AUC 0.83 comparable to ZAHARA (P = .66). CONCLUSIONS: CARPREG I and ZAHARA scores underestimate cardiac risk for lower risk pregnancies in these women. Of the three risk schemes, CARPREG I performed least well in predictive capacity. Clinical factors specific to the population studied are comparable to stratification schemes.

Perioperative electrophysiology study in patients with tetralogy of Fallot undergoing pulmonary valve replacement will identify those at high risk of subsequent ventricular tachycardia.

BACKGROUND: Ventricular tachyarrhythmias are the most common cause of death in patients with repaired tetralogy of Fallot (TOF), but predicting those at risk remains a challenge. An electrophysiology study (EPS) has been proposed to risk stratify patients with TOF. OBJECTIVE: We sought to evaluate a perioperative EPS-guided approach to risk stratify patients with TOF undergoing pulmonary valve replacement (PVR) and guide concomitant cryoablation. METHODS: A prospective cohort study of patients with TOF undergoing an EPS at the time of PVR from 2006 to 2017 was conducted at 2 centers. Patients inducible at the time of pre-PVR had undergone concomitant cryoablation in addition to PVR. A repeat post-PVR EPS was performed in those initially inducible to guide implantable cardioverter-defibrillator (ICD) implantation. RESULTS: Of 70 patients who underwent a pre-PVR EPS, 34 (49%) had inducible sustained ventricular tachycardia (VT): 25 monomorphic VT and 9 polymorphic VT. Among patients undergoing cryoablation, 14 (45%) had inducible VT and underwent ICD implantation. During a mean follow-up period of 6.1 ± 3.2 years, 3 patients (21%) had appropriate ICD shocks for symptomatic VT. There was an average of 2.3 shocks (range 1-4 shocks), and the mean time to first shock post-device implantation was 3.6 years (range 2.9-4.3 years). Among patients with negative pre- or post-PVR EPS results, 2 had VT requiring radiofrequency ablation and/or subsequent ICD implantation. There were no arrhythmic deaths. CONCLUSION: A pre-PVR EPS identified patients with higher-risk TOF undergoing PVR. Despite empirical VT cryoablation at the time of PVR, a high percentage of patients remained inducible for VT. In this high-risk cohort, post-PVR EPS evaluation is important to identify patients at risk of VT despite cryoablation.

Noninvasive predictors of perioperative atrial arrhythmias in patients with tetralogy of Fallot undergoing pulmonary valve replacement.

BACKGROUND: Patients with tetralogy of Fallot (TOF) have increased risk of atrial arrhythmias. HYPOTHESIS: A measure of atrial dispersion, the P-wave vector magnitude (Pvm), can identify patients at risk for perioperative atrial flutter (AFL) or intra-atrial re-entrant tachycardia (IART) in a large TOF cohort. METHODS: We performed a blinded, retrospective analysis of 158 TOF patients undergoing pulmonary valve replacement between 1997 and 2015. History of AFL/IART was documented using electrocardiogram, Holter monitor, exercise stress test, implanted cardiac device, and electrophysiology study. P-R intervals, Pvm, QRS duration, and QRS vector magnitude were assessed from resting sinus-rhythm 12-lead electrocardiograms and identification of those with AFL/IART was determined. RESULTS: Fourteen patients (8.9%) were found to have AFL/IART. Pvm, QRS duration, and QRS vector magnitude significantly differentiated those with AFL/IART from those without on univariate analysis: 0.09 ± 0.04 vs 0.18 ± 0.07 mV, 161.3 ± 21.9 vs 137.7 ± 31.4 ms, and 1.2 (interquartile range, 1.0-1.2) vs 1.6 mV (1.0-2.3), respectively (P < 0.05 for each). The Pvm had the highest area under the ROC curve (0.88) and was the only significant predictor on multivariate analysis, with odds ratio of 0.02 (95% confidence interval: 0.01-0.53). P-R duration, MRI volumes, and right-heart hemodynamics did not significantly differentiate those with vs those without AFL/IART. CONCLUSIONS: In TOF patients undergoing pulmonary valve replacement, Pvm has significant value in predicting those with perioperative AFL/IART. These clinical features may help further evaluate TOF patients at risk for perioperative atrial arrhythmias. Prospective studies are warranted.

Noninvasive Predictors of Ventricular Arrhythmias in Patients With Tetralogy of Fallot Undergoing Pulmonary Valve Replacement.

OBJECTIVES: This study sought to test the hypothesis that a vectorcardiographic parameter, the QRS vector magnitude (QRSVm), can risk stratify those patients at risk for sustained spontaneous ventricular arrhythmias (VAs) or ventricular arrhythmia inducibility (VAI) in a large cohort of patients with tetralogy of Fallot (TOF). BACKGROUND: Patients with TOF have an increased risk of VAs, but predicting those at risk can often be challenging. METHODS: Blinded retrospective analyses of 177 TOF patients undergoing pulmonary valve replacement (PVR) between 1997 and 2015 were performed. VAI was evaluated by programmed electrical stimulation in 48 patients. QRS intervals and QRSVm voltage measurements were assessed from resting 12-lead electrocardiograms, and risk of VA was determined. Clinical characteristics, including imaging and cardiac catheterizations, were used for other modality comparisons. RESULTS: Sustained spontaneous VA occurred in 12 patients and inducible VA in 18 patients. Age and QRSVm were significant univariate predictors of VA. QRSVm was the only independent predictor of VAI (p < 0.001). Using a root mean square QRS value of 1.24 mV, the positive and negative predictive values were 47.9% and 97.8%, respectively, for spontaneous sustained VA. For VAI, using a QRSVm cutoff of 1.31 mV, positive and negative predictive values were 63.0% and 95.3%, respectively. CONCLUSIONS: In TOF patients undergoing PVR, older age was associated with increased spontaneous VA risk. Lower QRSVm predicted spontaneous VA or VAI risk with high negative predictive values. QRSVm is the only independent predictor of VAI. These clinical features may help further risk stratify TOF patients requiring therapies to prevent sudden death.

Factors Associated with the Accurate Diagnosis of Obesity.

Obesity is a growing epidemic, yet few patients with obesity receive a clinical diagnosis of obesity or appropriate counseling. We examined the socioeconomic and demographic factors associated with the accurate diagnosis of obesity during ambulatory care visits. We used data from the National Hospital Ambulatory and National Ambulatory Medical Care Surveys (NHAMCS and NAMCS) to determine if a patient with obesity had been clinically diagnosed with obesity during the visit by either of the following: (1) a diagnosis listed in the patient's record; or (2) the provider's answer to the question "despite the diagnoses listed, does this patient have obesity?" We used multivariate models to examine the association between the accurate diagnosis of obesity and socioeconomic and demographic factors. We examined 885,291,770 weighted office visits involving individuals 5 years of age and older between 2006 and 2010. Providers were less likely to diagnose obesity at office visits involving children (5-12 years) with obesity (23.4 %) than at visits for adolescents (13-21 years; 39.7 %), young adults (22-34 years; 45.4 %), adults (35-64 years; 43.9 %) or elderly adults (≥65 years; 39.6 %; P < 0.001 for all). Individuals with obesity residing in more highly educated areas were more likely to be diagnosed than those living in less highly educated areas (44.2 vs. 40.9 %; AOR 1.4; 95 % CI 1.2-1.6). Males with obesity were less likely to be diagnosed than females with obesity (36.1 vs. 45.8 %; AOR 0.7; 95 % CI 0.6-0.8). After controlling for socioeconomic-status we did not find a consistent difference in the diagnosis of obesity by race. The diagnosis of obesity was made at less than half of all office visits involving patients with obesity. Children, adolescents, elderly, males, and those living in less educated areas were less likely to be accurately diagnosed with obesity.

Approach to residual pulmonary valve dysfunction in adults with repaired tetralogy of Fallot.

Residual right ventricular outflow tract and pulmonary valve disease is common in adults with repaired tetralogy of Fallot. Chronic severe pulmonary regurgitation as a result of surgical repair can lead to myriad complications including right ventricular dysfunction, decreased exercise tolerance, right heart failure and symptomatic arrhythmias. The aim of restoring pulmonary valve integrity is to preserve right ventricular size and function with the intent of mitigating the development of symptoms and poor long-term outcomes. Right ventricular size thresholds by cardiac MRI have emerged beyond which reverse right ventricular remodelling after pulmonary valve replacement is less likely. Though pulmonary valve replacement has been shown to improve right ventricular dimensions and symptoms, no consistent improvement in right ventricular ejection fraction or objective measures of exercise capacity have been demonstrated. Furthermore, there are no long-term studies showing that normalisation of right ventricular size results in improved clinical outcomes. New transcatheter techniques of percutaneous pulmonary valve replacement have emerged with good short-term and mid-term outcomes, further adding to the complexity in determining 'when' and 'how' right ventricular outflow tract and pulmonary valve intervention should occur. With improved survival of these patients, the trend towards earlier pulmonary valve replacement at smaller right ventricular size and rapidly evolving transcatheter pulmonary valve techniques, the clinician must balance the goals of preserving right ventricular size and function in an attempt to prevent untoward outcomes with risks of multiple interventions in a patient's lifetime.

Atrial Fibrillation Ablation Without Pulmonary Vein Isolation in a Patient with Fontan Palliation.

In a patient with Fontan palliation and persistent atrial fibrillation two triggers were identified that initiated atrial fibrillation (AF) from the superior vena cava (SVC) and the right atrium. SVC triggers are more common in patients with a normal-sized left atrium. Eliminating these triggers prevented AF from being sustained in this patient and thus pulmonary vein isolation was not pursued. The patient has remained AF free for 3 years without medications or repeat ablation. Targeting of potential right-sided triggers for AF ablation, before pulmonary vein isolation, should be considered; such an approach may reduce risks in these complex patients.

A Case of Cough-induced Ventricular Tachycardia in a Patient with a Left Ventricular Assist Device.

In this case, the patient's ventricular tachycardia (VT) was specifically induced by coughing, which has not previously been described. Decreasing the rotational speed of the left ventricular assist device (LVAD) and increasing preload by stopping the patient's nitrates and reducing diuretic dose allowed improved filling of the left ventricle (LV) and increased LV volumes. When coughing recurred, the effects on the LV cavity were less pronounced and thus VT was reduced. Although ventricular arrhythmias are common after LVAD placement, this is a unique case in which VT was caused by coughing, which is ordinarily not considered arrhythmogenic.

Slow Pathway Modification in a Patient with D-Transposition of the Great Arteries and Atrial Switch Procedure.

Patients with systemic right ventricles are often not able to tolerate frequent, rapid, or incessant atrial arrhythmias without developing significant symptoms and ventricular dysfunction. Atrial arrhythmias are associated with an increased risk of ventricular arrhythmias and sudden cardiac death. Rhythm disturbances must be aggressively addressed in this population with frequent screening, follow-up, and treatment.

Ventricular Tachycardia in Congenital Pulmonary Stenosis.

With modern surgical techniques, there is significantly increased life expectancy for those with congenital heart disease. Although congenital pulmonary valve stenosis is not as complex as tetralogy of Fallot, there are many similarities between the 2 lesions, such that patients with either of these conditions are at risk for ventricular arrhythmias and sudden cardiac death. Those patients who have undergone surgical palliation for congenital pulmonary stenosis are at an increased risk for development of ventricular arrhythmias and may benefit from a more aggressive evaluation for symptoms of palpitations or syncope.

Vectorcardiographic predictors of ventricular arrhythmia inducibility in patients with tetralogy of Fallot.

INTRODUCTION: Vectorcardiography (VCG) may have predictive value in Tetralogy of Fallot (TOF) patients undergoing ventricular arrhythmia inducibility (VAI) electrophysiology studies (EPs). MATERIALS AND METHODS: Blinded, retrospective analyses of 37 adult TOF patients undergoing EPs prior to pulmonary valve replacements were performed (21 female, median age 37years). VAI was evaluated from EPs and resting 12-lead electrocardiograms, respectively using QRS and heart rate adjusted Q-T intervals, spatial QRS-T angles (peaks), T-wave and QRS-wave (QRSwave vc) component vector root mean squares. Differences were assessed (Student t-tests, Mann Whitney U-tests, Analysis of Variance). Relative risks were calculated. RESULTS: 16 patients had VAI (6 monomorphic, 10 polymorphic). Only the QRSwave vc showed significant differences between those with and without VAI, 10.5±2.4 dmV vs. 13.9±4.5dmV, respectively (p=0.002), area under the ROC curve of 0.78 and relative risk of 2.52. CONCLUSION: VCG evidence of depolarization differences was significant between TOF patients with and without inducible VA.

Pulmonic regurgitation and management challenges in the adult with tetralogy of fallot.

OPINION STATEMENT: Patients with tetralogy of Fallot (TOF) are living longer than ever because of advances in surgery in childhood since the 1950s. However, surgery in childhood is not a cure and remains only a palliative procedure because almost all patients will require further intervention throughout life. The most common intervention required in adulthood is pulmonary valve replacement (PVR) because of residual pulmonary regurgitation leading to right ventricular dilation and eventual dysfunction. The most appropriate timing for PVR remains difficult to determine and is based on many factors. Our practice is to weigh not only objective factors such as right ventricular size and function but also careful objective assessment of the patient's current quality of life and functional status.

Preprocedural imaging in patients with transposition of the great arteries facilitates placement of cardiac resynchronization therapy leads.

OBJECTIVE: The purpose of this study is to review a series of patients with complex congenital heart disease in whom preprocedural imaging was used to assist placement of cardiac resynchronization therapy (CRT) leads. BACKGROUND: CRT may be beneficial in patients with a failing systemic ventricle and transposition of the great arteries (TGA). However, complex coronary venous anatomy can be challenging for placement of CRT leads. METHODS: Between October 2006 and June 2012, seven patients with either dextro-TGA (d-TGA) or levo-TGA (l-TGA) underwent preprocedural imaging prior to placement of CRT leads (three, d-TGA and four, l-TGA). Three patients underwent cardiac computed tomography (CT) and four underwent coronary angiography, which included levophase imaging of the coronary sinus (CS) or direct contrast injection of the CS. Where CS anatomy was appropriate with drainage into the systemic venous circulation, a transvenous approach was planned. In all other cases, the patient was referred for surgical placement of epicardial leads. RESULTS: Seven patients were identified with either d-TGA or l-TGA who had undergone preprocedural imaging prior to placement of CRT leads (three, d-TGA and four, l-TGA). Three patients underwent cardiac CT and four underwent coronary angiography, which included levophase imaging of the CS or direct contrast injection of the CS. All seven patients had successful CRT lead placement guided by preprocedure imaging. Three patients required surgical placement whereas four were able to undergo transvenous placement. There were no complications. The majority of patients (four of seven) had improvement in New York Heart Association class as well as subjective improvement in exercise tolerance and energy. The majority of patients also had subjective improvement in systemic right ventricular function by echocardiogram and objective improvement in fractional area change of the right ventricle. The follow-up period ranged from 13 months to 55 months with a mean follow-up of 39 months. CONCLUSIONS: Placement of biventricular leads for CRT in patients with l-TGA or d-TGA is feasible. Preprocedural imaging of the CS allows for better assessment of its anatomy and helps determine procedural approach for CRT placement, thereby limiting unnecessary procedures. In the majority of patients, there was subjective improvement in functional status and right ventricular function; in addition, there was objective improvement in echocardiographic parameters of right ventricular function after CRT placement.