Permanent pacemaker insertion postmitral surgery: Do the atrial access and the origin of the sinoatrial node artery matter?

Rare origin of the sinoatrial node artery: an anatomic report and a brief review of the literature

Several studies reported anatomical variations in the sinoatrial node artery (SANa). Here, we report a rare variation in the origin of the SANa on a human adult male cadaver. During dissection, we identified the SANa originating from a large atrial branch of the right coronary artery (RCA). This branch originates at the level of the inferior border of the heart and courses upwards. The initial part of this vessel is tortuous, and then it follows a straight path parallel to the RCA along the anterior surface of the right atrium. After this part, the artery curves posteriorly and to the left until it reaches the lower border of the right auricle, where it closely approaches the RCA. Finally, the artery runs posteriorly and to the right to follow a course along the medial wall of the right auricle and right atrium to reach a location close to the region of the junction of the superior vena cava and right atrium, where it follows its path buried in the myocardium. After perforating the myocardium, this vessel gives rise to branches that are distributed to both atria in addition to the SANa. The SANa runs to the sinoatrial node in a precaval (anterior to the superior vena cava) course. We also tried to characterize the vessels radiologically. The knowledge of the anatomical variations of the SANa is of the utmost importance for cardiologists and heart surgeons to better understand cardiac disease and accurately plan and execute cardiac interventions and surgical procedures.

A simple transseptal approach versus the conventional left atrial approach for mitral valve procedures: a retrospective study

Background

Having good exposure to the mitral apparatus during mitral valve replacement is a vital decision every cardiac surgeon must take. This study was conducted to compare the simple transseptal approach and the conventional left atrial approach for mitral valve procedures, to evaluate the safety and efficacy of the simple transseptal approach during open heart mitral valve procedures, as the conventional left atrial approach may not provide optimal exposure, especially in unfavorable anatomical and operative situations.

Methods

This is a retrospective study. It has been conducted on 140 patients who were diagnosed with heart diseases that required mitral valve replacement. Surgeries were performed in the Cardiothoracic Surgery Department. Mitral procedure was done through median sternotomy incision under general anesthesia on a cardiopulmonary bypass machine with cold antegrade cardioplegia. Demographic data, preoperative diagnosis, intraoperative findings, hospital stay, complications, and mortality were documented and revised.

Results

One hundred and forty patients were enrolled in this study with a median age of 39 years, and no significant differences as regards the baseline demographic data as age, sex, and body mass index (BMI). A total of 68 patients underwent mitral valve replacement through the simple transseptal approach and 72 patients through the conventional left atrial approach. Both studied groups had insignificant differences as regards bypass time, re-operation rate, postoperative complications, hospital stay, and mortality.

Conclusion

The simple transseptal approach through the midpoint of the fossa ovalis could be a safe and even favorable alternative to the traditional left atriotomy approach in certain difficult operative situations during mitral valve replacement surgery.

Graphical abstract

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.