Outcomes of Atrial Arrhythmia Surgery in Patients With Congenital Heart Disease: A Systematic Review.

Background The improved life expectancy of patients with congenital heart disease is often accompanied by the development of atrial tachyarrhythmias. Similarly, the number of patients requiring redo operations is expected to continue to rise as these patients are aging. Consequently, the role of arrhythmia surgery in the treatment of atrial arrhythmias is likely to become more important in this population. Although atrial arrhythmia surgery is a well-established part of Fontan conversion procedures, evidence-based recommendations for arrhythmia surgery for macroreentrant atrial tachycardia and atrial fibrillation in other patients with congenital heart disease are still lacking. Methods and Results Twenty-eight studies were included in this systematic review. The median reported arrhythmia recurrence was 13% (interquartile range, 4%-26%) during follow-up ranging from 3 months to 15.2 years. A large variation in surgical techniques was observed. Based on the acquired data, biatrial lesions are more effective in the treatment of atrial fibrillation than exclusive right-sided lesions. Right-sided lesions may be more appropriate in the treatment of macroreentrant atrial tachycardia; evidence for the superiority of additional left-sided lesions is lacking. There are not enough data to support the use of exclusive left-sided lesions. Theoretically, prophylactic atrial arrhythmia surgery may be beneficial in this population, but evidence is currently limited. Conclusions To be able to provide recommendations for arrhythmia surgery in patients with congenital heart disease, future studies should report outcomes according to the type of preoperative arrhythmia, underlying congenital heart disease, lesion set, and energy source. This is essential for determining which surgical techniques should ideally be applied under which circumstances.

The Effects of Valvular Heart Disease on Atrial Conduction During Sinus Rhythm.

Different arrhythmogenic substrates for atrial fibrillation (AF) may underlie aortic valve (AV) and mitral valve (MV) disease. We located conduction disorders during sinus rhythm by high-resolution epicardial mapping in patients undergoing AV (n = 85) or MV (n = 54) surgery. Extent and distribution of conduction delay (CD) and block (CD) across the entire right and left atrial surface was determined from circa 1880 unipolar electrogram recordings per patient. CD and CB were most pronounced at the superior intercaval area (2.5% of surface, maximal degree 6.6%/cm2). MV patients had a higher maximal degree of CD at the lateral left atrium than AV patients (4.2 vs 2.3%/cm2, p = 0.001). A history of AF was most strongly correlated to CD/CB at Bachmann's bundle and age. Although MV patients have more conduction disorders at the lateral left atrium, disturbed conduction at Bachmann's bundle during sinus rhythm indicates the presence of atrial remodeling which is related to AF episodes.

Tetralogy of Fallot in the Current Era.

Only few studies have reported long-term outcome of the transatrial-transpulmonary approach in the current era of management of tetralogy of Fallot (ToF). We investigated 15-year outcome of correction via a transatrial-transpulmonary approach in a large cohort of successive patients operated in the 21st century. All infant ToF patients undergoing transatrial-transpulmonary ToF correction between 2000 and 2015 were included (N = 177, 106 male, median follow-up 7.1 (interquartile range 3.0-10.9) years. Data regarding postoperative complications, reinterventions, development of atrial and ventricular arrhythmia, cardiac function, and survival were evaluated. Prior shunting was performed in 10 patients (6%). The transatrial-transpulmonary approach resulted in valve-sparing surgery in 57 patients (32%). Postoperative surgical complications included junctional ectopic tachycardia (N = 12, 7%), pericardial (N = 10, 6%) or pleural effusion (N = 7, 3%), chylothorax (N = 7, 4%), bleeding requiring reoperation (N = 4, 3%), and superficial wound infection (N = 1). Fifty-one patients underwent 68 reinterventions, mainly due to pulmonary restenosis (PS) (N = 57). ToF correction at age <2 months and double outlet or double-chambered right ventricle variants of the ToF spectrum were independent predictors for reintervention. Patients undergoing valve-sparing ToF correction had a significant longer PR-free survival than those with a transannular patch (8.5 [95% confidence interval 6.8-10.3] years vs 1.1 [95% confidence interval 0.8-1.5] years; P < 0.001). Overall mortality was 2.8%; mortality rates were higher in premature/dysmature newborns (0.7% vs 9.5%; P < 0.001). Although the 15-year outcome of the transatrial-transpulmonary approach in terms of postoperative complications and mortality rates is excellent, the high incidence of moderate and severe PR is worrisome. Valve-sparing surgery was associated with a substantially lower incidence of PR, yet was surgically not possible in the majority of patients.

Concomitant arrhythmia surgery in patients with congenital heart disease.

OBJECTIVES: Atrial tachyarrhythmia, including atrial fibrillation (AF), atrial flutter (AFL) and intra-atrial reentrant tachycardia (IART), occur frequently in patients with congenital heart disease (CHD), who may undergo multiple surgical procedures throughout life. However, data on the effectiveness of concomitant arrhythmia surgery in CHD patients are scarce. METHODS: Outcome of concomitant arrhythmia surgery for AF or AFL/IART was examined in 66 successive patients [31 men (47%); age at surgery: 56 ± 14 (24-78) years] with various CHD. RESULTS: Concomitant arrhythmia surgery was performed in patients with a history of only AF (n = 46, 70%), only AFL/IART (n = 6, 9%) or a combination of AF and AFL/IART (n = 14, 21%). Median follow-up after arrhythmia surgery was 2 (1-4) years. AF reoccurred in 40 patients (67%), of whom 13 (22%) only had early recurrences; none of the patients with only AFL or IART prior to arrhythmia surgery developed AF after arrhythmia surgery. Recurrence-free survival of late AF was 4.6 years and differed according to the type of AF prior to surgery. Late recurrence-free survival at 3-year follow-up was 71% for paroxysmal AF, 45% for persistent AF and 20% for long-standing persistent AF (P = 0.047). Age at arrhythmia surgery was an independent predictor for late AF recurrence (odds ratio 1.05, P = 0.006). AFL/IART occurred in 17 patients (26%) after arrhythmia surgery, which was de novo in 11 patients (17%). CONCLUSIONS: Arrhythmia surgery in CHD patients results in freedom from late AF recurrence for a small majority of patients after median follow-up of 2 years. (Long-standing) persistent AF and older age at arrhythmia surgery are related to higher recurrence rates.

Intraoperative Inducibility of Atrial Fibrillation Does Not Predict Early Postoperative Atrial Fibrillation.

BACKGROUND: Early postoperative atrial fibrillation (EPoAF) is associated with thromboembolic events, prolonged hospitalization, and development of late PoAF (LPoAF). It is, however, unknown if EPoAF can be predicted by intraoperative AF inducibility. The aims of this study are therefore to explore (1) the value of intraoperative inducibility of AF for development of both EPoAF and LPoAF and (2) the predictive value of de novo EPoAF for recurrence of LPoAF. METHODS AND RESULTS: Patients (N=496, 75% male) undergoing cardiothoracic surgery for coronary and/or valvular heart disease were included. AF induction was attempted by atrial pacing, before extracorporeal circulation. All patients were on continuous rhythm monitoring until discharge to detect EPoAF. During a follow-up period of 2 years, LPoAF was detected by ECGs and Holter recordings. Sustained AF was inducible in 56% of patients. There was no difference in patients with or without AF before surgery (P=0.159), or between different types of surgery (P=0.687). In patients without a history of AF, incidence of EPoAF and LPoAF was 37% and 2%, respectively. EPoAF recurred in 58% patients with preoperative AF, 53% developed LPoAF. There were no correlations between intraoperative inducibility and EPoAF or LPoAF (P>0.05). EPoAF was not correlated with LPoAF in patients without a history of AF (P=0.116), in contrast to patients with AF before surgery (P<0.001). CONCLUSIONS: Intraoperative AF inducibility does not predict development of either EPoAF or LPoAF. In patients with AF before surgery, EPoAF is correlated with LPoAF recurrences. This correlation is absent in patients without AF before surgery.

Unipolar atrial electrogram morphology from an epicardial and endocardial perspective.

BACKGROUND: Endo-epicardial asynchrony (EEA) and the interplay between the endocardial and epicardial layers could be important in the pathophysiology of atrial arrhythmias. The morphologic differences between epicardial and endocardial atrial electrograms have not yet been described, and electrogram morphology may hold information about the presence of EEA. OBJECTIVE: The purpose of this study was to directly compare epicardial to endocardial unipolar electrogram morphology during sinus rhythm (SR) and to evaluate whether EEA contributes to electrogram fractionation by correlating fractionation to spatial activation patterns. METHODS: In 26 patients undergoing cardiac surgery, unipolar electrograms were simultaneously recorded from the epicardium and endocardium at the inferior, middle, and superior right atrial (RA) free wall during SR. Potentials were analyzed for epi-endocardial differences in local activation time, voltage, RS ratio, and fractionation. The surrounding and opposite electrograms of fractionated deflections were evaluated for corresponding local activation times in order to determine whether fractionation originated from EEA. RESULTS: The superior RA was predisposed to delayed activation, EEA, and fractionation. Both epicardial and endocardial electrograms demonstrated an S-predominance. Fractionation was mostly similar between the 2 sides; however, incidentally deflections up to 4 mV on 1 side could be absent on the other side. Remote activation was responsible for most fractionated deflections (95%) in SR, of which 4% could be attributed to EEA. CONCLUSION: Local epi-endocardial differences in electrogram fractionation occur occasionally during SR but will likely increase during arrhythmias due to increasing EEA and (functional) conduction disorders. Electrogram fractionation can originate from EEA, and this study demonstrated that unipolar electrogram fractionation can potentially identify EEA.

Quantification of the Arrhythmogenic Effects of Spontaneous Atrial Extrasystole Using High-Resolution Epicardial Mapping.

BACKGROUND: Atrial extrasystoles (AES) can initiate atrial fibrillation. However, the impact of spontaneous AES on intra-atrial conduction is unknown. The aims of this study were to examine conduction disorders provoked by AES and to correlate these conduction differences with patient characteristics, mapping locations, and type of AES. METHODS AND RESULTS: High-resolution epicardial mapping (electrodes N=128 or N=192; interelectrode distance, 2 mm) of the entire atrial surface was performed in patients (N=164; 69.5% male; age 67.2±10.5 years) undergoing open-chest cardiac surgery. AES were classified as premature, aberrant, or prematurely aberrant. Conduction delay and conduction block were quantified during sinus rhythm and AES and subsequently compared. Median incidence of conduction delay and conduction block during sinus rhythm was 1.2% (interquartile, 0%-2.3%) and 0.4% (interquartile, 0%-2.1%). In comparison, the median incidence of conduction delay and conduction block during 339 AES was respectively 2.8% (interquartile, 1.3%-4.6%) and 2.2% (interquartile, 0.3%-5.1%) and differed between the types of AES (prematurely aberrant>aberrant>premature). The degree of prematurity was not associated with a higher incidence of conduction disorders (P>0.05). In contrast, a higher degree of aberrancy was associated with a higher incidence of conduction disorders; AES emerging as epicardial breakthrough provoked most conduction disorders (P≥0.002). AES caused most conduction disorders in patients with diabetes mellitus and left atrial dilatation (P<0.05). CONCLUSIONS: Intraoperative high-resolution epicardial mapping showed that conduction disorders are mainly provoked by prematurely aberrant AES, particularly in patients with left atrial dilation and diabetes mellitus or emerging as epicardial breakthrough.

Intra-operative mapping of the atria: the first step towards individualization of atrial fibrillation therapy?

INTRODUCTION: Atrial fibrillation (AF), an age-related progressive disease, is becoming a worldwide epidemic with a prevalence rate of 33 million. Areas covered: In this expert review, an overview of important results obtained from previous intra-operative mapping studies is provided. In addition, our novel intra-operative high resolution mapping studies, its surgical considerations and data analyses are discussed. Furthermore, the importance of high resolution mapping studies of both sinus rhythm and AF for the development of future AF therapy is underlined by our most recent results. Expert commentary: Progression of AF is determined by the extensiveness of electropathology which is defined as conduction disorders caused by structural damage of atrial tissue. The severity of electropathology is a major determinant of therapy failure. At present, we do not have any diagnostic tool to determine the degree of electropathology in the individual patient and we can thus not select the most optimal treatment modality for the individual patient. An intra-operative, high resolution scale, epicardial mapping approach combined with quantification of electrical parameters may serve as a diagnostic tool to stage AF in the individual patient and to provide patient tailored therapy.

Early ventricular tachyarrhythmias after coronary artery bypass grafting surgery: Is it a real burden?

BACKGROUND: The prevalence of ventricular dysrhythmias (VD) [ventricular premature beats (VPBs), ventricular couplets (Vcouplets), ventricular runs (Vruns)] after coronary artery bypass grafting (CABG) has so far not been examined. The goal of this study is to examine characteristics of VD and whether they precede ventricular tachyarrhythmias (VTA) during a postoperative follow-up period of 5 days using continuous rhythm registrations. In addition, we determined predictive factors of VD/VTA. METHODS: Incidences and burdens of VD/VTA were calculated in patients (N=105, 83 male, 65±9 years) undergoing primary, on-pump CABG. Independent risk factors were examined using multivariate analysis. RESULTS: VPBs, Vcouplets, and Vruns occurred in respectively 100%, 82.9%, and 48.6% with corresponding burdens of 0.05%, 0%, and 0%. Sustained ventricular tachycardia (VT) and ventricular fibrillation (VF) did not occur in our cohort. Independent risk factors for VD included male gender, mitral valve insufficiency, hyperlipidemia, and age ≥60 years. CONCLUSIONS: VD are common in patients with coronary artery disease after CABG. Despite high incidences of these dysrhythmias, corresponding burdens are low and sustained VT or VF did not occur. Incidences were highest on the first postoperative day and diminished over time.