Superior Transseptal Approach Research Articles

Superior transseptal versus left atriotomy approaches in isolated mitral valve surgery

ObjectiveThe superior transseptal approach to mitral valve surgery offers improved exposure compared with left atriotomy; however, concerns remain regarding postoperative arrhythmias and pacemaker placement. This study investigates intraoperative parameters and postoperative outcomes in these approaches. MethodsRetrospective review of 259 adults undergoing isolated mitral valve repair or replacement over a 10-year period was performed. Exclusion criteria included previous history of permanent pacemaker placement and concomitant cardiac procedures. The primary outcome evaluated was postoperative permanent pacemaker placement. Secondary outcomes included postoperative new-onset atrial fibrillation, new-onset arrhythmias, major adverse cardiovascular events, length of stay, and mortality. ResultsOf 259 surgeries, 116 were performed via left atriotomy and 143 via superior transseptal approach. The overall incidence of postoperative permanent pacemaker placement was 3.0%, with similar rates (left atriotomy 1.7% vs superior transseptal 4.2%, P = .30). The incidence of new-onset atrial fibrillation (31.0% vs 42.7%, P = .055) and arrhythmias in general (37.1% vs 49.0%, P = .06) was similar. Rates of other secondary outcomes, such as major adverse cardiovascular events and mortality, were similar between cohorts. In addition, cardiopulmonary bypass and aortic crossclamp times did not differ. Interestingly, intensive care unit (55 vs 73 hours, P = .04) and postoperative length of stay (6.8 vs 9.0 days, P = .002) were shorter after left atriotomy. ConclusionsThe superior transseptal approach provides optimal exposure while preserving similarly low rates of postoperative morbidity and mortality to left atriotomy. There is no difference in the incidence of postoperative permanent pacemaker placement and new-onset arrhythmias.

Comparative study of outcomes of different approaches in redo mitral valve surgery

Background Redo mitral valve replacement surgery is a challenging procedure as the access of the mitral valve mandates good exposure yet mitral visualization may not be sufficient as previous cardiac operations may complicate mitral valve exposure, as adhesions and loss of mobility in the surrounding tissues may be present. In such cases, the conventional left atrial incision may not offer satisfactory visualization in the surgical site of the valve. Therefore, several alternative approaches have been proposed, such as superior trans-septal approach, for satisfactory visualization of the mitral valve intra-operatively. Patients and methods Between January 2017 and November 2021, 100 patients were enrolled and with 50 patients randomly assigned in each group. Group one on patients undergoing redo surgery via a superior trans-septal approach and group two undergoing redo surgery via left atrial approach. Results Transeptal approach provides same results like left atrial approach in redo mitral valve surgery. Conclusion We conclude that the transseptal approach when compared to left atrial in redo patients provides comparable results in the intraoperative as well as postoperative outcomes

Dual linear lesions for right atrial flutter after mitral valve surgery via the superior transseptal approach.

The superior transseptal approach (STA) for mitral valve surgery is associated with a higher risk of developing macroreentrant incisional atrial flutter (AFL) than the left atrial approach. This study aimed to describe the linear lesions for the complex AFL circuit after the STA and to propose an option for the linear ablation target site. Of the 26 patients who underwent radiofrequency catheter ablation for AFL after mitral valve surgery, data from seven patients with STA incisions were retrospectively analyzed. All patients who had undergone the STA had incisional AFL rotated in a long loop within the right atrium (RA) and cavo-tricuspid isthmus (CTI)-dependent AFL. The linear lesions were created in the CTI, the superior RA vestibule, and between the RA-free wall incision or the septal incision and the inferior vena cava. Procedural success was achieved with dual linear lesions in the CTI and superior RA vestibule. Two of seven patients had AFL recurrence during a mean observation period of 22.5 ± 16.7months. The circuits of recurrent AFL were CTI-dependent AFL and perimitral AFL, respectively. No AFL recurrence was noted with reconduction of the superior RA vestibular lesion. Dual linear lesions in the CTI and superior RA vestibule are an effective treatment option for RA macroreentrant AFL after the STA.

Atrial approaches in mitral valve surgery: a propensity analysis of differences in the incidence of clinically relevant adverse effects

BackgroundThe lack of evidence on complications using mitral valve approaches leaves the choice of risk exposure to the surgeon’s preference, based on individual experience, speed, ease, and quality of exposure.MethodsThe present study analysed patients undergoing mitral valve surgery using a superior transseptal approach or a left-atrial approach between 2006 and 2018. We included first-time elective mitral valve procedures, isolated, or combined, without a history of rhythm disturbances. We used propensity score matching based on 26 perioperative variables. The primary endpoint was the association between the superior transeptal approach and clinically significant adverse outcomes, including arrhythmias, need for a permanent pacemaker, cerebrovascular events, and mortality.ResultsA total of 652 patients met the inclusion criteria; 391 received the left atrial approach, and 261 received the superior transseptal approach. After matching, 96 patients were compared with 69 patients, respectively. The distribution of the preoperative and perioperative variables was similar. There was no difference in the incidence of supraventricular tachyarrhythmias or the need for treatment. The incidence of nodal rhythm (p = 0.008) and length of stay in intensive care (p = 0.04) were higher in the superior transseptal group, but the need for permanent pacemaker implantation was the same. Likewise, there was no difference in the need for anticoagulation due to arrhythmia, the incidence of cerebrovascular events or mortality in the postoperative period or in the long-term follow-up.ConclusionWe did not find an association with permanent heart rhythm disorders or any other significant adverse clinical outcome. Therefore, the superior transeptal approach is useful and safe for mitral valve exposure.

Treatment of atrial tachycardia arising after superior transseptal approach mitral valve surgery: Insights from ultra‐high‐density mapping to prevent atrioventricular block

Mitral valve surgery employing a superior transseptal approach (STA) is associated with arrhythmogenicity and intra-atrial conduction delay, despite being optimal for visualization of the surgical field. It is sometimes difficult to treat atrial tachycardias (AT) that arise after STA. To investigate AT circuits that arise after STA in detail in order to identify the optimal ablation line, using ultra high-resolution mapping (UHRM). We retrospectively analyzed 12 AT from 10 patients (median age 70 years, 9 males) who had undergone STA surgery. The tachycardias were mapped using the Rhythmia mapping system (Boston Scientific, Natick, Massachusetts). The 12 STA-related AT (STA-AT) circuits were classifiable as follows according to location of the optimal ablation line: (1) peri-septal incision STA-AT (n = 3), (2) cavotricuspid isthmus dependent STA-AT (n = 7) and (3) biatrial tachycardia (n = 2). Radiofrequency (RF) application terminated 11 of the 12 STA-AT. We found that difference in STA-AT circuit type was due to characteristics of the septal incision line made for STA. UHRM was important in identifying optimal ablation sites that did not create additional conduction disturbances in the right atrium. ATs after STA involve complex arrhythmia circuits due to multiple and long incision lines in the right atrium. Accurate understanding of the arrhythmia circuit and sinus conduction in the right atrium after STA is recommended for treating post-surgical tachycardia in a minimally invasive manner. This article is protected by copyright. All rights reserved.

Transseptal versus left atrial approach for mitral valve surgery: postoperative need for pacemaker.

Concerns exist about higher rates of pacemaker implantation using the extended superior transseptal approach for mitral valve surgery. This study aims to compare the extended superior transseptal and the left atrial approach regarding the need for pacemaker implantation after mitral valve surgery. We performed a retrospective analysis of the data of patients undergoing mitral valve surgery through either a sternotomy and transseptal approach or a mini-thoracotomy and left atrial approach in a single centre in the period January 2010 to May 2021. The primary outcome was the evaluation of the postoperative pacemaker implantation rate. Overall, 677 patients were included, 333 with transseptal and 344 with left atrial approach, and 58 (8.6%) patients underwent pacemaker implantation postoperatively. There was no significant difference in the rate of pacemaker implantation between the 2 groups [overall: 34 (10.2%) vs 24 (7%), P = 0.133; for sinus node dysfunction: 12 (3.6%) vs 9 (2.6%), P = 0.459; for high-degree atrioventricular block: 22 (6.6%) vs 15 (4.4%), P = 0.199; transseptal vs left atrial approach, respectively]. A subgroup analysis of the relative effect of transseptal versus left atrial approach on the rate of postoperative pacemaker implantation revealed mitral replacement as a statistically significant confounder (P = 0.019). The exclusion of patients undergoing concomitant cardiac procedures did not lead to a statistically significant difference in the pacemaker implantation rate between the 2 approaches. The analysis of the data of these patients shows no significant difference in the rate of permanent pacemaker implantation between the extended superior transseptal and the left atrial approach for mitral valve surgery.

Rhythm disorders after isolated mitral valve surgery: Consideration of the variations of the sinoatrial nodal artery in choice of atriotomy.

Background This study aims to investigate the effect of atriotomy approaches applied in mitral valve surgery and variations of the sinoatrial nodal artery on postoperative arrhythmias and the need for a temporary or permanent pacemaker. Methods Data of 241 patients (108 males, 133 females, mean age: 53.7±12.3 years; range, 18 to 82 years) who underwent isolated mitral valve surgery with a median sternotomy between January 2009 and December 2019 were retrospectively analyzed. The patients were divided into three groups according to the surgical approach for mitral valve exploration as left atriotomy (n=47), transseptal (n=131), and superior transseptal (n=63). By scanning the hospital records, the origin of the sinoatrial nodal artery was determined in the coronary angiography images obtained before surgery. Postoperative rhythm changes were analyzed based on electrocardiography and telemetry recordings. Results Temporary pacing was required in 31 (49.2%) patients in the superior transseptal group, 40 (30.5%) patients in the transseptal group, and 12 (25.5%) patients in the left atriotomy group, indicating a statistically significantly higher rate in the superior transseptal group (p=0.013). Permanent pacemaker implantation was required in only one patient (superior transseptal), indicating no significant difference among the groups. The first-degree atrioventricular block was seen in 28 (44.4%) patients in the superior transseptal group, 42 (32.1%) patients in the transseptal group, and 13 (27.7%) patients in the left atriotomy group (p=0.130). The PR interval in the postoperative period was longer in the superior transseptal group than in the left atriotomy group in patients with the sinoatrial nodal artery originating from the right coronary artery (p=0.049). No significant difference was observed among the surgical approaches regarding the PR interval in patients with the sinoatrial nodal artery originating from the left circumflex coronary artery after surgery. Conclusion We believe that the choice of atriotomy in isolated mitral valve surgery and sinoatrial nodal artery variations do not affect permanent arrhythmia alone. Still, the superior transseptal approach causes the electrical conduction to slow down temporarily more than the left atriotomy and transseptal method.

Electrophysiological Characteristics of Atrial Tachycardia After Mitral Valve Surgery via a Superior Transseptal Approach.

Electrophysiological Characteristics of Atrial Tachycardia After Mitral Valve Surgery via a Superior Transseptal Approach.

Superior trans-septal approach for minimally invasive mitral valve surgery via right small thoracotomy.

Minimally invasive mitral valve surgery (MIMVS), despite its challenges, is not a rare procedure. However, MIMVS via a right small thoracotomy must be performed using long-shafted surgical instruments and thoracotomy instruments specialized for minimally invasive cardiac surgeries. We have performed 12 cases of MIMVS via right small thoracotomy using the superior trans-septal approach and secured a surgical visual field that easily allows a finger to reach the mitral valve annulus without using special instruments for minimally invasive cardiac surgery. We named this technique the "drawer-case technique." In conclusion, MIMVS via right thoracotomy using the superior trans-septal approach can be performed easily and safely, similar to mitral valve surgery performed via median sternotomy.

Comparison of Left Atriotomy and Superior Transseptal Approaches in Mitral Valve Surgery.

To compare the operative and post-operative outcomes of mitral valve surgery (MVS) with a superior transseptal (STS) approach and a left atriotomy (LA) approach. In a tertiary academic center, the charts of patients who underwent MVS between 2012 and 2016 were analyzed retrospectively. A total of 135 patients underwent MVS. Forty patients who underwent MVS with the STS approach were enrolled in the study as the STS group. In the same period, we selected 40 patients who underwent MVS with the LA approach to serve as the control group (LA group). Two groups were operated by the same surgeon. To minimize the bias related to the lack of randomization in this observational study, LA group patients were selected using propensity score matching. According to the study design, the preoperative characteristics of gender, age, mitral valve stenosis, and mitral valve insufficiency were matched (P = .368, P = .920, P = .250 and P = .057, respectively). The cardiopulmonary bypass time was 91.2 ± 12.1 minutes in the superior transseptal group and 72.8 ± 6.4 minutes in the left atriotomy group (P < .001). Additionally, duration of clamp time was significantly shorter in the left atriotomy group (P < .001). Estimated blood loss was significantly less in patients with a left atriotomy (535.8 ml versus 658.0 mL, P < .001). Duration of intensive care unit stay and hospitalization time were significantly longer in patients who underwent the superior transseptal approach compared with patients who underwent left atriotomy (P < .001 versus P < .001, respectively). Post-operative dysrhythmia rate and mortality rate were similar between the groups. Our study demonstrated that MVS with LA decreased cardiopulmonary bypass time, duration of clamp time, amount of hemorrhage, duration of intensive care unit stay, and hospitalization time compared with MVS with STS.

Transaortic Repair as Bailout Procedure for Left Atrial Tear in Redo Mitral Valve Surgery via Superior Transseptal Approach

We encountered a tear of the left atrium with severe calcification during redo mitral surgery, and report a technique for its repair. An 82-year-old woman underwent redo mitral valve replacement. The mitral valve was performed via a superior transseptal approach. The atriotomy was closed directly. The roof of the left atrium was found to be torn after aortic de-clamping. There was no remaining intact left atrial tissue on the aortic side. Patch closure was performed using transaortic stitches passing through the subaortic curtain to fix the patch. The left atrial roof and atrial septum were closed with the same patch.

Clinicopathological and surgical experience with primary cardiac tumors

Intracardiac tumors are rare neoplasms that present with clinical features of obstruction, embolization, conduction disturbances, and constitutional symptoms. Complete surgical resection under cardiopulmonary bypass offers the best prospect of disease-free survival. Data of 30 consecutive patients who underwent resection of an intracardiac mass at St. Vincent's Hospital from 1990 to 2012 were reviewed. The patients presented with dyspnea (33%), palpitations or arrhythmias (20%), and recurrent pulmonary edema (6%). There was a history of embolic stroke in 46%. Intracardiac masses were identified using preoperative echocardiography. Resection was performed on cardiopulmonary bypass via a modified Dubost (superior transseptal) approach in 78%, a left atriotomy in 11%, and a biatrial approach in 5%. Twenty-eight (93%) masses were identified as neoplastic, predominantly myxomas (62%). There was no mortality at 30 days. On long-term follow-up (mean 9 years, range 1-19 years) there were 5 deaths; 83% of patients were still alive. Cardiac tumors are rare and an important differential diagnosis in the context of unexplained obstructive symptoms, emboli, and conduction abnormalities. Myxomas are the most common cardiac neoplasm. Solid tumors are more common, more likely to be associated with heart failure, and best excised in one whole part, whereas papillary tumors are more likely to be associated with neurological symptoms, and more likely to be resected by piecemeal removal. Prompt and complete resection under cardiopulmonary bypass is the safest approach.

A modified cryo-maze procedure via the superior transseptal approach

The superior transseptal approach provides excellent exposure for mitral valve reconstruction. For atrial fibrillation, cryoablation is less invasive, simpler, and safer than the Cox maze operation. Combining the superior transseptal approach and cryoablation for mitral valve procedures yields a high recovery rate from atrial fibrillation, similar to that of radiofrequency ablation. Cryoablation-related complications such as thromboembolic events or requirement for a permanent pacemaker were not observed in our consecutive series. Cryoablation is also cost-effective.

Partial transplant cardiectomy mitral exposure

Case Previous operation Index operation Outcome Although a traditional groove of Sondergaard left atriotomy incision gives adequate mitral valve exposure in most instances, for difficult cases alternative approaches can be helpful. Radical approaches to the difficult mitral valve through sternotomy have included azygos division with superior vena cava mobilization, superior vena cava transection, and the superior transseptal approach. Drawbacks to these approaches include loss of azygos venous drainage, possible stenosis of the reconstructed superior vena cava, and possible sinoatrial node dysfunction. In a difficult mitral case, however, possible transient sinus node dysfunction is a small trade-off in light of the generally excellent exposure the transseptal exposure provides, and so this approach has become relatively common. Occasionally, though, even the transseptal incision does not provide good mitral exposure through a sternotomy. The partial cardiectomy approach begins with a standard superior transseptal incision, with bicaval cannulation and caval snares. After aortic crossclamping, the right atrium is opened on the appendage, the dome of the left atrium is identified, and a transatrial septal incision through the fossa ovalis is carried onto the dome, leaving enough atrium toward the aorta for easy reconstruction, as depicted by Smith and Guiraudon and colleagues. The right atrial and atrial septal incisions are carried down toward but short of the inferior vena cava and coronary sinus, respectively. If this transseptal exposure is insufficient, the aorta is transected just above the sinotubular junction, the atrial dome incision is extended, and the heart is retracted anteriorly. If mitral exposure is still inadequate, the pulmonary artery is also transected just above the sinotubular junction, and the dome atriotomy is continued leftward in front of the left pulmonary veins and behind the left atrial appendage. The heart is rolled toward the feet, exposing all 4 valves (Figure 1). After the mitral operation, closure proceeds similarly to a heart transplant: the left atrium, followed by the medial right atrium (the free wall of the right atrium can be left unsewn until after crossclamp release), the

A Novel Criterion for Conduction Block After Catheter Ablation of Right Atrial Tachycardia After Mitral Valve Surgery

One operative approach to the mitral valve, the superior transseptal incision, is proarrhythmic because of extensive atriotomies. The objective of this study is to describe complex atrial tachycardias (ATs) that occur after this approach and propose methods to verify lines of block as an end point for catheter ablation. Of the 69 patients who had electrophysiological studies for AT after mitral valve surgery, 20 patients had prior superior transseptal incisions. Of these, 14 had complex ATs involving the lateral right atrium (RA). There were 9 dual-loop, 4 single-loop, and 1 focal tachycardias. Lateral wall ablation was performed either by creating a linear lesion from the lateral atriotomy to the inferior vena cava, superior vena cava, or tricuspid annulus or by ablating focally in the lateral RA. After a single ablation procedure, conduction block in the lateral wall was verified in 10 of 14 patients using 1 of 2 distinct patterns of block. One pattern consisted of late activation in an anterolateral corridor of the RA, and a second pattern consisted of wide-spaced double potentials. Recurrent conduction through the lateral wall lesions was associated with intraprocedural and late recurrences of ATs. The optimal end point for ablating ATs after mitral valve surgery with the superior transseptal approach is to establish lines of block that can be recognized by characteristic patterns of activation in the lateral RA. A novel criterion for lateral conduction block after catheter ablation is identification of a late-activated corridor in the anterolateral RA.

Sinus Node Artery-preserving Superior Transseptal Approach: A Simple Technique

With the use of the superior transseptal approach during mitral valve surgery, good exposure of the mitral valve can be achieved with simple traction sutures, which minimize the risk of deformation of the mitral valve. For this reason, we routinely perform mitral valvoplasty using the superior transseptal approach; however, we, occasionally encounter cases that develop postoperative atrial dysrhythmia. We have therefore, devised a very simple technique for preservation of the sinus node artery in the superior transseptal approach, which is effective for reducing the incidence of postoperative sinus node dysfunction. In this technique, during incision of the dome of the left atrium, the sinus node artery is carefully dissected and preserved.

Improved Combined Superior-Transseptal Approach to the Mitral Valve

In mitral valve surgery, the combined superior-transseptal approach gives excellent exposure of the mitral valve, but it is lengthy and complex. A modified version of this approach was made without cutting the right atrial appendage and the dome of the right atrium. This shorter procedure was evaluated in 30 patients aged 4-61 years undergoing complex mitral valve operations including mitral repair (33.3%), reoperation (30%), and small left atrium (30%). The mitral valve was exposed well in all cases. Because of the shorter incision, closure was relatively easy. The aortic crossclamp time was 117 +/- 29.9 min (range, 53-173). There were no major complications. Cardiac rhythm resumed spontaneously after release of the aortic clamp in 93.3% of patients, including 36.7% who regained sinus rhythm from arrhythmia preoperatively. There was no heart block, bleeding, or mortality. Results at 3 months were good. Despite a decreased operative field, this modified approach provided adequate exposure for all the required techniques. The benefits of this approach are a shorter incision in the atrial muscle, and simplified closure technique.

Superior Transseptal Approach to Mitral Valve Is Associated With a Higher Need for Pacemaker Implantation Than the Left Atrial Approach

Several studies suggest that the superior transseptal approach to mitral valve surgery leads to sinus node dysfunction. The clinical consequences are not known. Consecutive patients undergoing surgery for mitral valve disease from November 16, 1994 through January 26, 2004 were retrospectively evaluated. The surgeons used either the superior transseptal (group A) or left atrial approach (group B). The risk of pacemaker implantation associated with the superior transseptal approach as compared with the left atrial approach was estimated using the multivariate Cox regression analysis to adjust for possible confounders. We included 577 patients, 150 in group A and 427 in group B. Forty-four patients had a pacemaker implanted after the surgery; 17 in group A and 27 in group B (p = 0.010). The superior transseptal approach was an independent risk factor of pacemaker implantation in multivariate analysis (hazard ratio 2.2 [1.2 to 4.1], p = 0.014). Nineteen patients had a pacemaker implanted because of sinus node dysfunction; 9 in group A and 10 in group B (p = 0.017). Group A was an independent predictor of pacemaker implantation because of sinus node dysfunction in bivariate analyses. The risk of pacemaker implantation because of atrioventricular conduction disturbances was not different between the groups (p = 0.178). The superior transseptal approach has a higher risk of clinically significant sinus node dysfunction than the left atrial approach.

The Superior Transseptal Surgical Approach to Mitral Valve Creates Slow Conduction

Atrial tachycardia is very frequent after mitral valve surgery using the superior transseptal approach. Sixteen patients operated on for mitral valve disease (superior transseptal approach = Group A, n = 9, and left atrial approach = Group B, n = 7) underwent radiofrequency catheter ablation of atrial tachycardia guided by electroanatomic mapping. Twenty-six consecutive patients without previous cardiac surgery with typical atrial flutter served as controls (Group C). Atrial tachycardia occurred earlier after the operation in Group A than in Group B (median 97 vs 2,159 days, P = 0.003). Typical atrial flutter was the most frequent circuit in all groups (Group A-7 patients, Group B-5 patients, Group C-26 patients). Three patients in Group A developed right atrial incisional tachycardia. Ten of 14 tachycardia circuits (typical atrial flutter, n = 7, incisional tachycardia, n = 3) in Group A depended on the corridor between the right atrial part of the atriotomy and the tricuspid annulus. Slow conduction during typical atrial flutter was detected in this corridor in Group A, but not in the corresponding region in Groups B and C (P < 0.001). The cycle length of typical atrial flutter was longer in Groups A and B than in Group C (mean 283 ms and 282 ms vs 233 ms, P = 0.003). Patients in Group B with typical atrial flutter had larger right atria than patients in Group A or Group C (mean 156 mL vs 96 mL and 113 mL, P = 0.033). The superior transseptal incision may predispose to atrial tachycardia by creating slow conduction between the atriotomy and the tricuspid annulus.

Atrial Incision Affects the Incidence of Atrial Tachycardia After Mitral Valve Surgery

Atrial fibrillation is common after mitral valve surgery. We do not know the incidence of atrial tachycardia and how it depends on the surgical approach used. The subjects of the study were 213 consecutive patients who had surgery for mitral valve disease from January 1, 2001, through January 26, 2004. The surgeons used either the superior transseptal approach (69 patients, group A) or left atrial approach (144 patients, group B). An investigator, blinded for the approach used, analyzed all 12-lead electrocardiograms taken during the admission after the operation. The data were analyzed using the Cox regression analysis as time from the operation until documentation of atrial tachycardia or atrial fibrillation on a 12-lead electrocardiogram. Hazard ratio (95% confidence interval) is reported. The superior transseptal approach (2.0 [1.1 to 3.5], p = 0.023), age 60 years or more (2.3 [1.2 to 4.6], p = 0.015), and male sex (2.6 [1.3 to 5.2], p = 0.007) were independent predictors of atrial tachycardia. Age 60 years or more was the only independent predictor of atrial fibrillation (2.0 [1.2 to 3.3], p = 0.007). Although atrial tachycardia was less frequent than atrial fibrillation in group B (p < 0.001), atrial tachycardia was as common as atrial fibrillation in group A (p = 0.149). The superior transseptal approach has a higher risk of atrial tachycardia than the left atrial approach. Atrial tachycardia has different predictors than atrial fibrillation and constitutes a significant problem, especially after the superior transseptal approach. These results emphasize the need to distinguish between atrial tachycardia and atrial fibrillation-two entities with different pathophysiology, therapy, and also epidemiology.