Biatrial Anastomosis Research Articles

Implantation of a permanent pacemaker following orthotopic heart transplantation: a systematic review and meta-analysis.

Orthotopic heart transplant (OHT) is among the final armamentariums for end-stage heart disease. Many patients who have had OHT require a post-transplant permanent pacemaker (PPM) implantation due to an abnormal conduction system. We aimed to evaluate the risk of mortality and acute rejection in patients with OHT who had received PPM compared to patients without PPM and to determine predictors for PPM placement in this population. We comprehensively searched for studies from MEDLINE, EMBASE, and Cochrane databases from inception to September 2023. Inclusion criteria focused on patients who had undergone OHT and PPM implantation post-transplant. Data from each study were combined using a random-effects model. Results were expressed as relative risk (RR) or odd ratios (OR) with a 95% confidence interval (CI). A total of 9 studies were included in this meta-analysis incorporating a total of 54,848 patients (3.3% had PPM). The pooled all-cause mortality rate among patients with PPM post-OHT was 26% (95% CI: 19-33%, I2 = 1%). There were no differences between post-heart transplant patients with PPM and those without PPM in risk of all-cause mortality (RR 0.76, 95% CI: 0.43-1.34; I2 = 45%) and acute rejection (RR 1.22, 95% CI: 0.74-2.00, I2 = 59%). Bi-atrial anastomosis was associated with an increased risk of PPM implantation post-OHT (OR 7.74, 95% CI: 3.55-16.91, I2 = 0%), while pre-OHT mechanical circulatory support (MCS) was associated with a decreased risk of PPM implantation post-OHT (OR 0.45, 95% CI 0.27-0.76, I2 = 0%). There were no significant differences in all-cause mortality or acute rejection between post-OHT recipients who required PPM compared to those who did not receive PPM. Further, bi-atrial anastomosis portended the need for PPM implantation, while MCS was associated with a decreased occurrence of PPM.

Cardiac implantable electronic devices following orthotopic heart transplantation: insights on indications and outcomes from a single centre experience

Abstract Background Need for cardiac implantable electronic devices (CIED) after orthotopic heart transplantation (OHT) ranges from 7 to 24% of cases depending on several patient and procedural related factors. Purpose The aims of this study were to investigate the frequency, indications and the predictors of CIED implantation (especially permanent pacemaker [PPM]) following biatrial anastomosis OHT. Methods A retrospective, single centre, observational study was conducted, including all the patients who underwent OHT between May 1990 and October 2023 at our Institution. For each patient clinical and procedural information were collected and a long-term active follow-up was performed. The primary endpoint of the study was PPM or implantable cardioverter defibrillator (ICD) implantation while all-cause mortality or de novo OHT was a secondary endpoint. Uni- and multivariable logistic regression analyses were performed to identify factors associated with PPM implantation. Results Overall, 546 patients were included and followed-up for a median of 8 years [IQR 1.2-14.3]. During this time frame, 89 (16.3%) patients required PPM implantation (only one patient [0.2%] underwent ICD implantation) at median time of 110 days [IQR 25-2230] after OHT. The main indication for PPM implantation was the development of sinus node dysfunction in 60 patients (67.4%) whereas 29 (32.6%) patients with atrioventricular block required PPM implantation. During follow-up, 265 deaths (48.5%) occurred but no significant differences in long-term prognosis were observed between patients requiring CIED implantation and those who did not (45.5% vs. 49.1%, p-value=0.53, figure). At multivariable analysis, impaired renal function (i.e. low eGFR), cardiac allograft vasculopathy, the occurrence of severe heart transplant rejection and a higher BMI were factors associated with PPM implantation (table). Conclusions Among patients undergoing OHT with biatrial anastomosis technique, PPM implantation is not uncommon but it does not negatively impact on prognosis. Several factors, especially severe heart transplant rejection, cardiac allograft vasculopathy and impaired renal function can help identifying patients at higher risk of PPM.TableFigure

Frequency, Risk Factors, and Clinical Outcomes of Late-Onset Atrial Flutter in Patients after Heart Transplantation.

Aims: Atrial flutter (AFL) is a common late-onset complication after heart transplantation (HTX) and is associated with worse clinical outcomes. Methods: This study investigated the frequency, risk factors, and outcomes of late-onset post-transplant AFL. We analyzed 639 adult patients undergoing HTX at the Heidelberg Heart Center between 1989 and 2019. Patients were stratified by diagnosis and type of late-onset post-transplant AFL (>90 days after HTX). Results: A total of 55 patients (8.6%) were diagnosed with late-onset post-transplant AFL, 30 had typical AFL (54.5%) and 25 had atypical AFL (45.5%). Patients with AFL were younger at HTX (p = 0.028), received more biatrial anastomosis (p = 0.001), and presented with moderate or severe tricuspid regurgitation (56.4%). Typical AFL was associated with graft rejection (p = 0.016), whereas atypical AFL was associated with coronary artery disease (p = 0.028) and stent implantation (p = 0.042). Patients with atypical AFL showed a higher all-cause 1-year mortality (p = 0.010) along with a higher rate of graft failure after diagnosis of AFL (p = 0.023). Recurrence of AFL was high (83.6%). Patients with catheter ablation after AFL recurrence had a higher 1-year freedom from AFL (p = 0.003). Conclusions: Patients with late-onset post-transplant AFL were younger at HTX, received more biatrial anastomosis, and showed a higher rate of moderate or severe tricuspid regurgitation. Typical AFL was associated with graft rejection, whereas atypical AFL was associated with myocardial ischemia, graft failure, and mortality. Catheter ablation represents a viable option to avoid further episodes of late-onset AFL after HTX.

Modified biatrial heart transplantation after bilateral bidirectional cavo-pulmonary shunts.

We describe a patient who underwent modified biatrial anastomosis heart transplantation after the bilateral Glenn procedure. We introduced a new surgical technique to use the native central pulmonary artery as systemic venous return, which was anastomosed to right atrium, and then, biatrial anastomosis was performed.

Impact of a Modified Bicaval Anastomoses Technique on Outcome After Orthotopic Heart Transplantation

<h3>Purpose</h3> Implantation techniques for orthotopic heart transplantation (HTx) have evolved during the centuries. By now, bicaval anastomosis are preferred compared to biatrial as they are reported to cause less pacemaker implantation, however they can increase duration of warm ischemia. Recently new approaches of modified bicaval techniques in order to minimize warm ischemia are gaining popularity in the literature. <h3>Methods</h3> Between 2010 and 2021 n=218 patients underwent HTx in our department. The recipients were retrospectively reviewed and divided regarding their anastomoses technique. Anastomoses were sutured either in biatrial, bicaval or in a modified bicaval manner with suturing of the superior cava vein and A. pulmonalis anastomosis after removing the aortic cross-clamp during the reperfusion. <h3>Results</h3> The majority of patients were transplanted in bicaval (n=179), followed by biatrial (n=34) and modified bicaval technique (n=5). Warm ischemia was 66±15 min for bicaval, 62±11 min for biatrial but only 42±8 min for modified bicaval technique (p<0.01). Bonferroni correction revealed no significant differences between bicaval and biatrial (p=0.18) but between both bicaval and modified bicaval (p<0.01) and biatrial and modified bicaval technique (p=0.05). Incidence of severe primary graft dysfunction was comparable between bicaval (29.9 %) and biatrial (27.3 %) anastomosis. In contrast, in patients with modified bicaval technique primary graft dysfunction did not occur. The same effect was observed for perioperative neurological events as well as thoracic bleeding. In addition, stay on intensive care unit was significantly shorter for modified bicaval patients (p=0.02). Incidence of postoperative pacemaker implantation was 16.7 % for biatrial compared to 3.2 % for bicaval and 0 % for modified bicaval technique (p=0.03). <h3>Conclusion</h3> While incidence of postoperative need for pacemaker implantation was increased in patients with biatrial anastomoses, there was no significant difference regarding warm ischemia and perioperative adverse events compared to bicaval technique. Although the results for modified bicaval technique are only preliminary by now, we were able to report promising results with significant shorter duration of warm ischemia and decreased perioperative complications indicating an optimized anastomoses technique for HTx.

Two Hearts, Believing in Just One Mind: What Is the Rhythm?

A 59-year-old patient who underwent orthotropic heart transplantation for end-stage nonischemic cardiomyopathy presented 2 months later with palpitations and fatigue. He had a history of hypertension, diabetes mellitus, and well-controlled HIV. Of note, pretransplant imaging had demonstrated a persistent left-sided superior vena cava draining into a large coronary sinus. Therefore, a biatrial anastomosis surgical technique (involving suturing the donor right atrium to a portion of the native right atrium with preservation of the native and donor coronary sinuses) was used at the time of transplantation.

B-PO05-204 LATE ONSET ATYPICAL ATRIAL FLUTTER IN A TRANSPLANTED HEART

Cardiac denervation, allograft rejection and vasculopathy increase the risk of cardiac arrhythmias and pose management challenges in a heart transplant patient. To discuss the management of atrial arrhythmia in a transplanted heart. N/A A 71-year-old Caucasian woman with a history of orthotopic heart transplant in 2001, paroxysmal atrial fibrillation, and transplant vasculopathy status post left circumflex artery stent presented with palpitations. External monitoring revealed supraventricular tachycardia. Twelve lead ECG confirmed an atrial flutter with variable block. Echocardiography showed normal ventricular function. Cardiac biopsy showed focal moderate cellular allograft rejection. Left heart catheterization did not show significant coronary obstruction. The finding of graft rejection prompted commencement of steroids. Following steroid therapy, repeat biopsy was negative for rejection; however, atrial arrhythmia persisted requiring multiple cardioversions. Antiarrhythmic drug therapy caused intolerable side effects. An electrophysiology study revealed atypical mitral flutter in the donor atria. Catheter ablation of the anterior mitral line terminated the flutter. Allograft rejection causes inflammation and fibrosis leading to slowing of conduction in the atria forming the substrate for intra-atrial arrhythmia. Bi-atrial anastomosis might have increased the risk of transmitral flutter in the donor heart. Catheter ablation should be considered for late onset atrial arrhythmia in transplant patients.

Immuno-Electrophysiological Mechanisms of Functional Electrical Connections Between Recipient and Donor Heart in Patients With Orthotopic Heart Transplantation Presenting With Atrial Arrhythmias.

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Case report: Transcatheter valve repair with Cardioband: a new treatment option for secondary tricuspid regurgitation in cardiac transplant patients.

BackgroundTricuspid regurgitation (TR) is the most frequent valvular complication after cardiac transplantation. As in native hearts, the role of surgical therapy particularly in secondary TR is unclear due to high procedural risk and unsatisfying results. Currently, percutaneous techniques are under development for TR repair with less procedural risk and promising preliminary results.Case summaryWe present a 67-year-old man who underwent heart transplantation (biatrial anastomosis) because of ischaemic heart disease 15 years ago and aortic valve replacement in 2010. Because of progressive severe dyspnoea (New York Heart Association Class III) in 2018 and signs of right heart failure with ascites he underwent transthoracic echocardiography which showed normal graft function, but massive TR of functional aetiology. The heart team decision was an interventional approach using the Cardioband System (Edwards Lifesciences) to treat TR based on the high risk associated with a third cardiac surgery and impaired right ventricular function. The procedure was performed in general anaesthesia with transoesophageal echocardiography and fluoroscopic guidance. Tricuspid regurgitation improved from massive to mild with a mean pressure gradient of 2.9 mmHg.DiscussionThis is the first case report of Cardioband implantation in tricuspid position in a heart transplant patient with the good technical and clinical result, suggesting that this technique might offer a treatment option to highly selected post-transplant patients with secondary severe TR and high surgical risk.

A Tale of 2 Nodes After Orthotopic Heart Transplant

We report the case of a 30-year-old man who underwent orthotopic heart transplant via biatrial anastomosis technique. His post-operative electrocardiogram showed atrial dissociation, which is infrequently seen with newer surgical techniques in heart transplantation. (Level of Difficulty: Advanced.)

Functional tricuspid valve insufficiency after cardiac transplantation: Which factor is the most important?

ObjectivesTricuspid insufficiency (TI) is the most common valvular complication following orthotopic heart transplantation (HTx) and in serious cases is associated with increased mortality. In this study, we analyze the possible variables influencing TI following HTx and aim to identify the most important risk factors and mechanisms responsible for functional TI development and progression.MethodsWe identified the incidence of TI within our institute in 857 of 1515 patients who underwent HTx using the biatrial anastomosis technique in the years between 1986 and 2010. The risk factors that could influence TI were retrospectively analyzed in detail in a representative group of 152 patients with identical TI distribution as found in the entire program. Patients of the group were subdivided into 2 groups according to the severity of TI: patients with TI grade ≤2 and those with TI grade >2. Impact on long-term survival (>15 years) was assessed.ResultsIn univariable analysis, study variables such as age of recipient (P = .027), donor to recipient right atrium anterior wall ratio (P < .001), tricuspid annulus anterior to septal leaflet excursion ratio (P = .001), dialysis (P = .026), and total biopsy number (P = .003) showed significant differences. The variables, height of recipient (P = .080), body mass index donor to body mass index recipient ratio (P = .080), and number of biopsies with more than moderate grade (P = .067) showed a trend toward significance in the development of severe TI after HTx. In multivariable analysis, we found an independent significant association between TI after HTx and donor to recipient right atrium anterior wall ratio, number of biopsies, and dialysis.ConclusionsChanges in tricuspid annulus geometry, number of biopsies, and dialysis are the most important risk factors for the development and progression of TI following cardiac transplantation. It could be prevented using modified operative techniques, noninvasive diagnostic modalities, and intensified ultrafiltration. In patients with biatrial anastomosis technique with generous atrial cuff, the presence of TI greater than grade 2 did not impact long-term survival.

Cardiac Implantable Electronic Devices Following Heart Transplantation.

Permanent pacemaker (PPM) implantation is required in a subset of patients (∼10%) for sinus node dysfunction or atrioventricular block both early and late after heart transplantation. The incidence of PPM implantation has decreased to<5% with the advent of bicaval anastamosis transplantation surgery. Pacing dependence upon follow-up has been variably reported. An even smaller percentage of transplantation recipients (1.5% to 3.4%) undergo implantable cardioverter-defibrillator (ICD) placement. Rigorous data are lacking for the use of ICDs in the transplantation population and is largely derived from cohort studies and case series. Sudden cardiac death occurs in approximately 10% of transplantation recipients, but multiple nonarrhythmic factors are believed to be responsible, including acute rejection, late graft failure with electromechanical dissociation, and ischemia due to cardiac allograft vasculopathy. This review provides a comprehensive analysis of the existing data regarding the role for PPMs and ICDs in this population, including leadless PPMs and subcutaneous ICDs, special considerations, and future directions.

Bicaval vs biatrial anastomosis techniques in orthotopic heart transplantation: An updated analysis of the UNOS database.

Despite the significant increase in the number of orthotopic heart transplants (OHT) performed yearly using the bicaval anastomosis technique, the impact on long-term outcomes remains a topic of debate. We analyzed the United Network for Organ Sharing (UNOS) database in search of the latest insight. We performed a retrospective analysis of the UNOS database from 2006 to 2016 to identify first-time OHT recipients. Patients were primarily stratified according to anastomosis technique: bicaval vs biatrial. Baseline characteristics and clinical status were recorded. The primary endpoint was all-cause mortality. Secondary outcomes included need for permanent pacemaker (PPM), and length of hospital stay (LOS). The Kaplan-Meier method was used to compare survival between the two groups. The Cox proportional hazards regression model was used to conduct multivariable analysis. Statistical significance established at P < .0001. A total of 26 990 patients were identified. Of those who met the inclusion criteria (21 597), 16 573 (77%) underwent bicaval anastomosis. There were no major differences in baseline characteristics between the two groups. The bicaval anastomosis technique was not associated with increased survival during the study period (hazard ratio: 0.97; P = .3557), but the bicaval group required postoperative PPM less often (2.51% vs 5.79%, P < .0001) and was associated with shorter LOS on multivariable analysis. The use of either bicaval or biatrial anastomosis during OHT offers comparable survival advantage. Nonetheless, bicaval anastomosis is associated with less need for postoperative PPM and slightly shorter LOS.

Permanent pacemaker implantation in pediatric heart transplant recipients: A systematic review and evidence quality assessment.

Bradyarrhythmias are a common complication following pediatric OHT and may require permanent pacemaker implantation (PPM). The purpose of this study was to investigate the incidence, predictors, and outcomes of children undergoing PPM implantation following OHT. A PRISMA-compliant systematic literature review was performed using the PubMed database and the Cochrane Library (end-of-search date: January 27, 2019). The Newcastle-Ottawa scale and the Joanna Briggs Institute tool were used to assess the quality of cohort studies and case reports, respectively. We analyzed data from a total of 11 studies recruiting 7198 pediatric patients who underwent heart transplant. PPM implantation was performed in 1.9% (n=137/7,198; 95% CI: 1.6-2.2) of the patients. Most patients underwent dual-chamber pacing (46%, 95% CI: 32.6-59.7). Male-to-female ratio was 1.3:1. Mean patient age at the time of OHT was 10.1±6.3. Overall, biatrial anastomosis was used in 62.2% (95% CI: 52.8-70.6) of the patients. The bicaval technique was performed in the remaining 37.8% (95% CI: 29.4-47.1). Sinus node dysfunction was the most frequent indication for PPM implantation (54.4%; 95% CI: 42.6-65.7) followed by AV block (45.6%; 95% CI: 34.3-57.3). The median time interval between OHT and PPM implantation ranged from 17days to 12.5years. All-cause mortality was 27.9% (95% CI: 18.6-39.6) during a median follow-up of 5years. PPM implantation is rarely required after pediatric OHT. The most common indication for pacing is sinus node dysfunction, and patients undergoing biatrial anastomosis may be more likely to require PPM.

Clinical and procedural characteristics predicting need for chronotropic support and permanent pacing post–heart transplantation

Postoperative bradycardia can complicate orthotopic heart transplantation (OHT). Previous studies suggested donor age and surgical technique as possible risk factors. However, risk factors in the era of bicaval anastomosis have not been elucidated. We sought to examine the association between donor/recipient characteristics with need for chronotropic support and permanent pacemaker (PPM) implantation in patients with OHT. All patients treated with OHT between January 2003 and January 2018 at the Hospital of the University of Pennsylvania were retrospectively evaluated until June 2018. Chronotropic support was given upon postoperative inability to increase the heart rate to patient's demands and included disproportionate bradycardia and junctional rhythm. A total of 820 patients (mean age 51.3 ± 12.6 years; 607, 74% men) underwent 826 OHT procedures (787 patients, 95.3% bicaval anastomosis). Patients who were exposed to amiodarone (odds ratio [OR] 2.30; 95% confidence interval [CI] 1.58-3.34; P < .001) and have older donor (OR 1.02; 95% CI 1.01-1.04; P = .001) were more likely to develop need for chronotropic support. In multivariable analysis, recipient age (OR 1.03; 95% CI 1.00-1.06; P = .04) and biatrial anastomosis (OR 6.12; 95% CI 2.48-15.09) were significantly associated with PPM implantation within 6 months of OHT. No association was found between pre-OHT amiodarone use and PPM implantation. No risk factors assessed were associated with PPM implantation 6 months post-OHT. Surgical technique and donor age were the main risk factors for the need for chronotropic support post-OHT, whereas surgical technique and recipient age were risk factors for early PPM implantation.

Right atrial function in pediatric heart transplant patients by echocardiographic strain measurements.

CAV is a major cause of mortality in PHTx patients. Research on echocardiographic indices to detect CAV focuses primarily on ventricular function and less is known about RAF. Thus, we primarily sought to evaluate RAF in PHTx patients with CAV. For secondary analysis, we compared RAF between PHTx patients and control patients and evaluated RAF with respect to rejection and surgical type. We retrospectively evaluated echocardiography derived RA strain indices in recipients <18years old and >1year from time of transplant. The RA strain phases included, reservoir (εs), conduit (εe), pump (εa), and respective strain rate indices (SRs, SRe, SRa). There were 36 PHTx patients and 14 age-, sex-matched control patients. There was a significant reduction in εs, εe, SRs, and SRe (P<0.001) in the PHTx patients when compared to controls. There was no difference between the CAV (+) and CAV (-) patients with respect to RAF indices. Furthermore, εs, εe, and SRe (P<0.05) were lower in patients with acute rejection (n=7) compared to those without (n=26). Patients with a bi-atrial anastomosis (n=14) had decreased εs, εa, SRs, SRa (P<0.05), compared to bi-caval anastomosis (n=24). PHTx patients have decreased RAF compared to healthy children. RAF does not differentiate PHTx patients based on the presence of CAV. RAF is also decreased in PHTx patients with rejection and in those transplanted with a bi-atrial anastomosis.

Left atrial appendage occlusion using a Watchman device in a transplanted heart with biatrial anastomosis

A percutaneous left atrial appendage (LAA) occlusion using a Watchman device was performed in a patient with prior biatrial anastomosis orthotopic heart transplant (OHT). Due to the anatomical changes following biatrial anastomosis, transesophageal echocardiography (TEE) imaging and transseptal puncture become technically challenging. We describe how the standard LAA views on TEE were obtained for device sizing, and how the transseptal puncture was modified to cross the scarred septum. This case demonstrates that LAA occlusion using a Watchman device in biatrial anastomosis OHT is safe and can successfully be done.

Sinus node dysfunction after heart transplantation-An analysis of risk factors and atrial pacing burden.

We investigated the development of sinus node dysfunction (SND) requiring pacemaker implantation after heart transplant (HTx) especially regarding pacing burden in these patients. Patients requiring a pacemaker for SND were compared to all other patients in an HTx cohort including transplant patients from 1981 to 2016. Sinus node dysfunction requiring pacemaker implantation developed in 118 patients (10%). These patients had received a biatrial anastomosis more frequently than those in the No SND group 95.8% vs 90.0% (P=.042). The ratio of reperfusion time to aortic cross-clamp time was significantly smaller in the SND group compared to the No SND group 71.7% vs 80.3% (P=.033). This also holds for the ratio of reperfusion time to ischemia time, which was 23.2% and 28.6%, respectively (P=.032). Pacing burden decreased from 90.5% to 66.3% after 2years and remained around this value in the remaining 4years of follow-up. We identified the biatrial anastomosis and a low ratio of reperfusion time to aortic cross-clamp time as well as to ischemia time as risk factors for SND requiring pacing. After implantation pacemakers continue to pace for over 60% of the time after 6years.

Experience on temporary and permanent cardiac pacing after heart transplantation

// Qiang Xu 1, 3 , Lin-Hai Xu 2, 3 , Bai-Ming Qu 1, 3 and Qi Xue 1, 3 1 Department of Cardiology, Zhejiang Provincial People's Hospital, Hangzhou 310014, China 2 Department of Cardiac Surgery, Zhejiang Provincial People's Hospital, Hangzhou 310014, China 3 People&rsquo;s Hospital of Hangzhou Medical College, Hangzhou 310014, China Correspondence to: Qi Xue, email: xueq@zjheart.com Bai-Ming Qu, email: qubm@zjheart.com Keywords: cardiac pacing; heart transplantation; permanent cardiac pacing; temporary cardiac pacing Received: August 07, 2017&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Accepted: December 28, 2017&nbsp;&nbsp;&nbsp;&nbsp;&nbsp; Published: January 02, 2018 ABSTRACT Objectives: To evaluate and summarize the indications and outcome of cardiac pacing after heart transplantation. Methods: We reviewed a total of 19 cases who received orthotopic heart transplantation with biatrial anastomosis at our hospital since 1997. Data of cases who received temporary or permanent cardiac pacing due to bradyarrhythmias during both perioperative and follow-up periods. Results: Nine cases received temporary cardiac pacing after heart transplantation. In addition, seven of these cases received temporary cardiac pacing during the perioperative period most of them spontaneously recovered. Two cases received temporary cardiac pacing at late stage post-surgery after discontinuance of anti-rejection drugs, and died because of cardiac function deterioration during hospitalization. Four cases received permanent cardiac pacing, three at late stage post-surgery, another during perioperative period. All three cases received implantation of a dual-chamber pacemaker via conventional approach. After pacemaker implantation, patients were followed up for 6 months to 11 years, and parameters were all within the normal range. Two cases underwent device replacement because of battery exhaustion. Another patient developed infective endocarditis and secondary multi-organ failure after pacemaker implantation and didn&rsquo;t survive. Conclusions: After orthotopic heart transplantation with biatrial anastomosis, the occurrence of bradyarrhythmia is higher during the perioperative period, which indicates the need for temporary cardiac pacing. A considerable number of cases will require cardiac pacing at the late stage post-implantation. Furthermore, bradycardia with severe heart failure may indicate signs of graft rejection.

Catheter ablation of organized atrial arrhythmias in orthotopic heart transplantation

Organized atrial arrhythmias (OAAs) are common after orthotopic heart transplantation (OHT). Some controversies remain about their clinical presentation, relationship with atrial anastomosis and electrophysiologic features. The objectives of this retrospective study were to determine the mechanisms of OAAs after OHT and describe the outcomes of radiofrequency catheter ablation (RFCA). Thirty consecutive transplanted patients (mean age 48 ± 17 years, 86.6% male) underwent 3-dimensional electroanatomic mapping and RFCA of their OAA from 2004 to 2012 at our center. Twenty-two patients had biatrial anastomosis and 8 had bicaval anastomosis. Macro-reentry was the arrhythmia mechanism for 96% of patients. The electrophysiologic diagnoses were: cavotricuspid isthmus (CTI)-dependent atrial flutter (AFL) in 93% of patients (n = 28); perimitral AFL in 3% (n = 1); and focal atrial tachycardia (FAT) in 3% (n = 1). In 5 patients with biatrial anastomosis, a right FAT was inducible. Primary RFCA success was obtained in 93% of patients. Mean follow-up time was 39 ± 26.8 months. Electrical repermeation between recipient and donor atria, present in 20% of patients (n = 6), did not account for any of the OAAs observed. Survival without OAA relapse at 12, 24 and 60 months was 93%, 89% and 79%, respectively. CTI-dependent AFL accounted for most instances of OAA after OHT, regardless of anastomosis type. Time from transplantation to OAA was shorter with bicaval than with biatrial anastomosis. RFCA was safe and provided good long-term results.