Atrial fibrillation recurrence and spontaneous conversion to sinus rhythm after cardiac surgery: Insights from 426 patients with continuous rhythm monitoring.

INTRODUCTION: Cardiac surgery may influence occurrence and persistence of atrial fibrillation (AF). In patients with a history of cardiac surgery and postoperative pacemaker or implantable cardioverter defibrillator implantation we attempted to quantify AF characteristics and investigate factors that influence AF recurrence. METHODS: In 426 patients (319 male; age: 73 SD: 9 years) with a history of cardiac surgery (364 CABG; 69 mitral valve; 57 aortic valve and 59 combination procedures) the heart rhythm history (mean: 351 days SD: 54 days) was reconstructed and investigated for AF recurrence patterns. RESULTS: AF developed and subsequently recurred in 75% of patients (n = 320). The mean AF burden in these patients was 0.21 (21% of the total observed time spent in AF) and 4085 episodes of AF were observed and analyzed. AF episodes spontaneously terminated within 24 h (n = 2509), 48 h (n = 700), 72 h (n = 279), and 1 week (n = 31). The probability of spontaneous conversion to sinus rhythm (SR) decreased with time spent in AF and plateaued after approximately 7 days. Patient age, LVEF and presence of coronary artery disease significantly influenced the probability of spontaneous conversion to SR. Type of cardiac surgery also significantly influenced AF episode characteristics. CONCLUSION: AF episodes are common in patients with a history of cardiac surgery. Spontaneous conversion to SR diminishes with increasing time spent in AF and is influenced by AF characteristics and several patient-related factors. Continuous monitoring can provide detailed information about AF recurrence that may immensely improve our understanding and influence the clinical management of AF.

Tricuspid valve annuloplasty and mitral valve replacement are associated with bradyarrhythmia after mitral valve surgery.

INTRODUCTION: Mitral valve surgery has developed into a strong subspecialty of cardiac surgery with operative techniques and outcomes constantly improving. The development of bradyarrhythmias after mitral valve surgery is not completely understood. METHODS: We investigated a cohort of 797 patients requiring mitral valve surgery with and without concomitant procedures. Incidences and predictors of pacemaker requirement as well as survival were analyzed. RESULTS: In the complete follow-up period (median follow-up time: 6.09 years [95% confidence interval [CI]: 5.94-6.22 years, maximum 8.77 years) 80 patients (10% of the complete cohort) required pacemaker implantation for bradyarrhythmia. The cumulative rate of pacemaker implantation was 6.4% at 50 days (48 patients) with most (54.2%) requiring pacing for atrioventricular block. Mitral valve replacement (odds ratio [OR]: 1.905; 95% CI: 1.206-3.536; p = .041) and tricuspid ring annuloplasty (OR: 2.348; 95% CI: 1.165-4.730, p = .017) were identified as operative risk factors of pacemaker requirement after mitral valve surgery. Insulin-dependent diabetes mellitus was also identified as a predictor of pacemaker requirement (OR: 4.665; 95% CI: 1.975-11.02; p = .001). There was no difference in survival in the paced and unpaced groups. CONCLUSIONS: After mitral valve surgery, a relevant subgroup of patients requires pacemaker implantation-most for atrioventricular block. We identified mitral valve replacement and tricuspid ring annuloplasty as significant operative risk factors and insulin-dependent diabetes mellitus as a demographic risk factor. While anatomic relationships help explain the operative risk factors the role of diabetes mellitus is not completely understood.

Incidental detection of single coil right ventricular lead perforation during aortic valve surgery.

It is unknown how many pacemaker and implantable cardioverter defibrillator (ICD) leads perforate during lead placement. Symptoms of a perforated lead include shortness of breath and chest pain. Signs of perforation can include a high pacing threshold, reduced lead sensing, and a high lead impedance. We present the case of a patient where perforation of the single coil right ventricular lead was not evident in imaging but incidentally detected during operative aortic valve replacement. The lead perforation rate during device implantation is around 1%-ICD leads have a higher perforation rate.

Etiology of tricuspid valve disease is a predictor of bradyarrhythmia after tricuspid valve surgery.

AIMS: The tricuspid valve is situated in close proximity to cardiac conduction tissue and damage to this tissue can affect postoperative rhythm. The aim of this study was to quantify the incidence of pacemaker requirement after tricuspid valve surgery and investigate predictors. METHODS: Data were collected via our operative data collection system and patient files. All patients who underwent surgical procedures of the tricuspid valve from 2004 until 2017 and lacked a pacemaker preoperatively were included in the study. RESULTS: In our cohort of 505 patients 54 required a pacemaker in the first 50 days after surgery. We calculated a 17.5% (95% confidence interval [CI], 13.5-21.3) risk of pacemaker implantation at 4 years postoperatively. Multivariate analysis identified preoperative active endocarditis (odds ratio 3.17; CI, 1.32-7.65; P = 0.010) and "inadequate pacemaker dependent rhythm" (defined as any intrinsic heart rate below 45 per minute requiring pacing) upon admission to the intensive care unit after surgery (odds ratio 5.924; CI, 2.82-12.44; P = 0.001) as predictors for pacemaker requirement in the first 50 days after surgery. Twenty-six pacemakers (48%) were implanted for atrioventricular block, 16 (30%) for sinus node dysfunction and 12 (22%) for atrial fibrillation. Kaplan-Meier analysis showed no difference in survival between the pacemaker and no pacemaker group. CONCLUSION: Surgery of the tricuspid valve has a high burden of postoperative pacemaker requirement. Preoperative active endocarditis and the initial postoperative rhythm are predictors. Understanding this allows for better decision-making regarding further medical/device therapy.

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

INTRODUCTION: We investigated the development of sinus node dysfunction (SND) requiring pacemaker implantation after heart transplant (HTx) especially regarding pacing burden in these patients. PATIENTS AND METHODS: Patients requiring a pacemaker for SND were compared to all other patients in an HTx cohort including transplant patients from 1981 to 2016. RESULTS: 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 2 years and remained around this value in the remaining 4 years of follow-up. CONCLUSION: 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 6 years.

A survey study on student preferences regarding pathology teaching in Germany: a call for curricular modernization.

BACKGROUND: Pathology is a discipline that provides the basis of the understanding of disease in medicine. The past decades have seen a decline in the emphasis laid on pathology teaching in medical schools and outdated pathology curricula have worsened the situation. Student opinions and thoughts are central to the questions of whether and how such curricula should be modernized. METHODS: A survey was conducted among 1018 German medical students regarding their preferences in pathology teaching modalities and their satisfaction with lecture-based courses. A qualitative analysis was performed comparing a recently modernized pathology curriculum with a traditional lecture-based curriculum. The differences in modalities of teaching used were investigated. RESULTS: Student satisfaction with the lecture-based curriculum positively correlated with student grades (spearman's correlation coefficient 0.24). Additionally, students with lower grades supported changing the curriculum (spearman's correlation coefficient 0.47). The majority supported virtual microscopy, autopsies, seminars and podcasts as preferred didactic methods. CONCLUSIONS: The data supports the implementation of a pathology curriculum where tutorials, autopsies and supplementary computer-based learning tools play important roles.

Recurrence of Atrial Fibrillation in Patients With New-Onset Postoperative Atrial Fibrillation After Coronary Artery Bypass Grafting.

Importance: New-onset postoperative atrial fibrillation (POAF) occurs in approximately 30% of patients undergoing coronary artery bypass grafting (CABG). It is unknown whether early recurrence is associated with worse outcomes. Objective: To test the hypothesis that early AF recurrence in patients with POAF after CABG is associated with worse outcomes. Design, Setting, and Participants: This Swedish nationwide cohort study used prospectively collected data from the SWEDEHEART (Swedish Web System for Enhancement and Development of Evidence-Based Care in Heart Disease Evaluated According to Recommended Therapies) registry and 3 other mandatory national registries. The study included patients who underwent isolated first-time CABG between January 1, 2007, and December 31, 2020, and developed POAF. Data analysis was performed between March 6 and September 16, 2023. Exposure: Early AF recurrence defined as an episode of AF leading to hospital care within 3 months after discharge. Main Outcomes and Measures: The primary outcome was all-cause mortality. Secondary outcomes included ischemic stroke, any thromboembolism, heart failure hospitalization, and major bleeding within 2 years after discharge. The groups were compared with multivariable Cox regression models, with early AF recurrence as a time-dependent covariate. The hypothesis tested was formulated after data collection. Results: Of the 35 329 patients identified, 10 609 (30.0%) developed POAF after CABG and were included in this study. Their median age was 71 (IQR, 66-76) years. The median follow-up was 7.1 (IQR, 2.9-9.0) years, and most patients (81.6%) were men. Early AF recurrence occurred in 6.7% of patients. Event rates (95% CIs) per 100 patient-years with vs without early AF recurrence were 2.21 (1.49-3.24) vs 2.03 (1.83-2.25) for all-cause mortality, 3.94 (2.92-5.28) vs 2.79 (2.56-3.05) for heart failure hospitalization, and 3.97 (2.95-5.30) vs 2.74 (2.51-2.99) for major bleeding. No association between early AF recurrence and all-cause mortality was observed (adjusted hazard ratio [AHR], 1.17 [95% CI, 0.80-1.74]; P = .41). In exploratory analyses, there was an association with heart failure hospitalization (AHR, 1.80 [95% CI, 1.32-2.45]; P = .001) and major bleeding (AHR, 1.92 [1.42-2.61]; P < .001). Conclusions and Relevance: In this cohort study of early AF recurrence after POAF in patients who underwent CABG, no association was found between early AF recurrence and all-cause mortality. Exploratory analyses showed associations between AF recurrence and heart failure hospitalization, oral anticoagulation, and major bleeding.

Aortic Root Replacement and Berlin Heart EXCOR Implantation in Marfan Syndrome.

Aortic regurgitation secondary to aortic aneurysmal disease with subsequent long-term volume overload of the left ventricle is associated with left ventricular dysfunction. In Marfan syndrome, ventricular dysfunction may exist independent of valvular disease (Marfan cardiomyopathy). We report of a 20-year-old Marfan syndrome patient presenting with severe aortic regurgitation and severe heart failure. Aortic surgery with concurrent biventricular paracorporeal assist device implantation was performed to bridge the patient to heart transplantation, which was performed successfully 21 weeks after aortic surgery. While the optimal strategy for this situation has not been described, the approach applied here appears a valid option.

Influence of pulmonary artery size on early outcome after the Fontan operation.

BACKGROUND: Small pulmonary arteries (PAs) are often considered as a contraindication for the Fontan operation (FO). The aim of this study was to evaluate if the PA size is still one of the major impact factors on the postoperative early outcome. METHODS: Data of 146 patients, with a median age of 2.0 years (range, 1.5 to 18 years) and a median weight of 12.45 kg (range, 7.7 to 64.7 kg) who underwent a modified FO in the same center between 2007 and 2012 were retrospectively analyzed with respect to the traditional McGoon ratio, Nakata index, and modified indices (measuring the narrowest diameters). RESULTS: Patients with a McGoon ratio of 1.6 or less (modified≤1.2) or a Nakata index of 150 mm2/m2 or less (modified≤100 mm2/m2) were not at a higher risk of longer mechanical ventilation (p=0.87 [0.1] and p=0.68 [0.52], respectively), longer stay (p=0.52 [0.18] and p=0.54 [0.38], respectively) in the intensive care unit, prolonged hospital stay (p=0.08 [0.26] and p=0.22 [0.29], respectively) or effusions (p=0.25 [0.37] and p=0.13 [0.06]), respectively). Younger and smaller children tended to have smaller PAs, but younger age (<24 months) and lower weight (<12 kg) were not predictive for poor early postoperative outcome. CONCLUSIONS: Small PAs do not significantly affect the early postoperative period after FO. In our opinion, there is no need to postpone the FO due to "smaller" PAs. The palliative procedures performed before FO to increase the size of the PA at the expense of volume overload of the single ventricle and the possible complications of prolonged cyanosis must be carefully weighed.

In vitro biological and mechanical evaluation of various scaffold materials for myocardial tissue engineering.

A cardiac patch is a construct devised in regenerative medicine to replace necrotic heart tissue after myocardial infarctions. The cardiac patch consists of a scaffold seeded with stem cells. To identify the best scaffold for cardiac patch construction we compared polyurethane, Collagen Cell Carriers, ePTFE, and ePTFE SSP1-RGD regarding their receptiveness to seeding with mesenchymal stem cells isolated from umbilical cord tissue. Seeding was tested at an array of cell seeding densities. The bioartificial patches were cultured for up to 35 days and evaluated by scanning electron microscopy, microscopy of histological stains, fluorescence microscopy, and mitochondrial assays. Polyurethane was the only biomaterial which resulted in an organized multilayer (seeding density: 0.750 × 10(6) cells/cm(2)). Cultured over 35 days at this seeding density the mitochondrial activity of the cells on polyurethane patches continually increased. There was no decrease in the E Modulus of polyurethane once seeded with cells. Seeding of CCC could only be realized at a low seeding density and both ePTFE and ePTFE SSP1-RGD were found to be unreceptive to seeding. Of the tested scaffolds polyurethane thus crystallized as the most appropriate for seeding with mesenchymal stem cells in the framework of myocardial tissue engineering.