Impact of concomitant surgical interventions on outcomes of septal myectomy in obstructive hypertrophic cardiomyopathy

BACKGROUND

Septal myectomy (SM) is offered to symptomatic patients with obstructive hypertrophic cardiomyopathy (oHCM) despite medical therapy. Frequently, patients undergo concomitant planned or ad-hoc mitral valve replacement (MVR), aortic valve replacement (SAVR), or coronary artery bypass grafting (CABG).

OBJECTIVES

We sought to assess characteristics and outcomes of patients with oHCM undergoing concomitant surgical interventions at the time of SM.

METHODS

The National Readmission Databases were used to identify all SM admissions in the United States (2010-2019). Patients undergoing SM were stratified into: isolated SM (±MV repair), SM + CABG only, SM + MVR, SM + SAVR, and SM + MVR + SAVR. Primary outcomes were in-hospital mortality, in-hospital adverse events, and 30-day readmission.

RESULTS

12,063 encounters of patients who underwent SM were included (56.1% isolated SM, 9.0% SM + CABG only, 17.5% SM + MVR, 13.1% SM + SAVR, and 4.3% SM + MVR + SAVR). Patients who underwent isolated SM were younger (54.3 vs. 67.1 years-old, p < 0.01) and had lower overall comorbidity burden. In-hospital mortality was lowest in isolated SM, followed by CABG only, SM + SAVR, SM + MVR, and SM + SAVR+MVR groups (2.3% vs. 3.7% vs. 5.3% vs. 6.7% vs. 13.7%, p < 0.01), respectively. SM with combined surgical interventions was associated with higher adverse in-hospital events (24.3% vs. 11.1%, p < 0.01) and 30-day readmissions (16.9% vs. 10.4%, p < 0.01). MV repair performed concomitantly with SM was not associated with increased in-hospital mortality (3.9% vs. 3.4%, p = 0.72; aOR 0.99; 95% CI: 0.54-1.80, p = 0.97]) or adverse clinical events.

CONCLUSIONS

In SM for oHCM, patients undergoing concomitant surgical interventions were characteristically distinct. Aside from MV repair, concomitant interventions were associated with worse in-hospital death, adverse in-hospital events, and 30-day readmission.

Prognosis of pacing-dependent patients with cardiovascular implantable electronic devices

BACKGROUND

Data on the prognostic significance of pacing dependency in patients with cardiovascular implantable electronic devices (CIEDs) are sparse.

METHODS

The prognostic significance of pacing dependency defined as absence of an intrinsic rhythm ≥ 30 bpm was determined in 786 patients with CIEDs at the authors' institution using univariate and multivariate regression analysis to identify predictors of all-cause mortality.

RESULTS

During 49 months median follow-up, death occurred in 63 of 130 patients with pacing dependency compared to 241 of 656 patients without pacing dependency (48% versus 37%, hazard ratio [HR] 1.34; 95% confidence interval [CI]: 1.02-1.78, P = 0.04). Using multivariate regression analysis, predictors of all-cause mortality included age (HR 1.07; 95% CI: 1.05-1.08, P < 0.01), history of atrial fibrillation (HR 1.32, 95% CI: 1.03-1.69, P < 0.01), chronic kidney disease (HR 1.28; 95% CI: 1.00-1.63, P = 0.048) and New York Heart Association (NYHA) class ≥ III (HR 2.00; 95% CI: 1.52-2.62, P < 0.01), but not pacing dependency (HR 1.15; 95% CI: 0.86-1.54, P = 0.35).

CONCLUSIONS

In contrast to age, atrial fibrillation, chronic kidney disease and heart failure severity as indexed by NYHA functional class III or IV, pacing dependency does not appear to be an independent predictor of all-cause mortality in patients with CIEDs.

Incidence, Risk Factors, and Outcomes Associated With Permanent Pacemaker Implantation Following Tricuspid Valve Surgery

BACKGROUND

Data regarding permanent pacemaker (PPM) implantation following tricuspid valve surgery (TVS) are limited. We sought to evaluate its incidence, risk factors, and outcomes.

METHODS AND RESULTS

Medicare beneficiaries who underwent TVS from 2013 to 2020 were identified. Patients who underwent TVS for endocarditis were excluded. The primary exposure of interest was new PPM after TVS. Outcomes included all-cause mortality and readmission with endocarditis or heart failure on follow-up. Among the 13 294 patients who underwent TVS, 2518 (18.9%) required PPM placement. Risk factors included female sex (relative risk [RR], 1.26 [95% CI, 1.17-1.36], P<0.0001), prior sternotomy (RR, 1.12 [95% CI, 1.02-1.23], P=0.02), preoperative second-degree heart block (RR, 2.20 [95% CI, 1.81-2.69], P<0.0001), right bundle-branch block (RR, 1.21 [95% CI, 1.03-1.41], P=0.019), bifascicular block (RR, 1.43 [95% CI, 1.06-1.93], P=0.02), and prior malignancy (RR, 1.23 [95% CI, 1.01-1.49], P=0.04). Tricuspid valve (TV) replacement was associated with a significantly higher risk of PPM implantation when compared with TV repair (RR, 3.20 [95% CI, 2.16-4.75], P<0.0001). After a median follow-up of 3.1 years, mortality was not different in patients who received PPM compared with patients who did not (hazard ratio [HR], 1.02 [95% CI, 0.93-1.12], P=0.7). PPM placement was not associated with a higher risk of endocarditis but was associated with a higher risk of heart failure readmission (HR, 1.28 [95% CI, 1.14-1.43], P<0.001).

CONCLUSIONS

PPM implantation frequently occurs after TVS, notably in female patients and patients undergoing TV replacement. Although mortality is not increased, it is associated with higher rates of heart failure rehospitalization.

Long-Term Atrioventricular Block Following Valve Surgery: Electrocardiographic and Surgical Predictors

BACKGROUND

Bradyarrhythmia requiring pacemaker implantation among patients undergoing valve surgery may occur even after several years, with unclear predictors. Our aim was to investigate the incidence of pacemaker implantation at different follow-up times and identify associated predictors.

METHODS

We conducted a retrospective study evaluating 1046 consecutive patients who underwent valve surgery at the Cardiac Surgery Division of Bologna University Hospital from 2005 to 2010.

RESULTS

During 10 ± 4 years of follow-up, 11.4% of these patients required pacemaker implantation. Interventions on both atrioventricular valves independently predicted long-term pacemaker implantation (SHR 2.1, 95% CI 1.2-3.8, p = 0.014). Preoperative atrioventricular conduction disease strongly predicted long-term atrioventricular block, with right bundle branch block as the major predictor (SHR 7.0, 95% CI 3.9-12.4, p < 0.001), followed by left bundle branch block (SHR 4.9, 95% CI 2.4-10.1, p < 0.001), and left anterior fascicular block (SHR 3.9, 95% CI 1.8-8.3, p < 0.001).

CONCLUSION

Patients undergoing valvular surgery have a continuing risk of atrioventricular block late after surgery until the 12-month follow-up, which was clearly superior to the rate of atrioventricular block observed at long-term. Pre-operative atrioventricular conduction disease and combined surgery on both atrioventricular valves are strong predictors of atrioventricular block requiring pacemaker implantation.

Implantable Triboelectric Nanogenerators for Self-Powered Cardiovascular Healthcare

Triboelectric nanogenerators (TENGs) have gained significant traction in recent years in the bioengineering community. With the potential for expansive applications for biomedical use, many individuals and research groups have furthered their studies on the topic, in order to gain an understanding of how TENGs can contribute to healthcare. More specifically, there have been a number of recent studies focusing on implantable triboelectric nanogenerators (I-TENGs) toward self-powered cardiac systems healthcare. In this review, the progression of implantable TENGs for self-powered cardiovascular healthcare, including self-powered cardiac monitoring devices, self-powered therapeutic devices, and power sources for cardiac pacemakers, will be systematically reviewed. Long-term expectations of these implantable TENG devices through their biocompatibility and other utilization strategies will also be discussed.

Concomitant ablation of atrial fibrillation: New pacemakers and early rhythm recovery

OBJECTIVE

New permanent pacemaker (PPM) implantation after concomitant atrial fibrillation (AF) ablation has been associated with surgical ablation (SA). We sought to determine factors for PPM use as well as early rhythm recovery.

METHODS

From 2004 through 2019, 6135 patients underwent valve surgery and were grouped: No AF (n = 4584), AF no SA (n = 346), and AF with SA (n = 1205) to evaluate predischarge PPM and 3-month rhythm recovery (intrinsic heart rate >40 beats per minute).

RESULTS

Overall, 282 (4.6%) patients required a predischarge PPM: atrioventricular node dysfunction in 75.3%, sick sinus syndrome in 19.1%, both (5%), and indeterminate (0.7%). Patients with AF had more PPMs: AF with SA (7.9%) versus AF no SA (6.9%) versus No AF (3.6%) (P < .001). For patients with AF, PPM rates were not significantly higher for ablation patients (7.6% SA vs 6.9% AF no SA; P = .56). There were differences in PPM by SA lesion set (biatrial 12.8%; left atrial only 6.1%; pulmonary vein isolation 3.0%; P < .001). Among patients with AF treated with 3-month PPM follow-up, rhythm recovery was common (35 out of 62 [56.5%]) and did not differ by lesion set. Rhythm recovery was seen in 63 out of 141 (44.7%) in the atrioventricular node dysfunction group versus 24 out of 35 (68.6%) in the sick sinus syndrome group (P = .011). In propensity score-matched groups, late survival was similar (P = .63) for new PPM patients.

CONCLUSIONS

Avoiding conduction system trauma and delaying implantation reduces the need for postoperative PPM. Rhythm recovery within 3 months is frequent, especially for patients with sick sinus syndrome. A conservative approach to the implantation of a new PPMs is warranted.

How robust are recommended waiting times to pacing after cardiac surgery that are derived from observational data?

AIMS

For bradycardic patients after cardiac surgery, it is unknown how long to wait before implanting a permanent pacemaker (PPM). Current recommendations vary and are based on observational studies. This study aims to examine why this variation may exist.

METHODS AND RESULTS

We conducted first a study of patients in our institution and second a systematic review of studies examining conduction disturbance and pacing after cardiac surgery. Of 5849 operations over a 6-year period, 103 (1.8%) patients required PPM implantation. Only pacing dependence at implant and time from surgery to implant were associated with 30-day pacing dependence. The only predictor of regression of pacing dependence was time from surgery to implant. We then applied the conventional procedure of receiver operating characteristic (ROC) analysis, seeking an optimal time point for decision-making. This suggested the optimal waiting time was 12.5 days for predicting pacing dependence at 30 days for all patients (area under the ROC curve (AUC) 0.620, P = 0.031) and for predicting regression of pacing dependence in patients who were pacing-dependent at implant (AUC 0.769, P < 0.001). However, our systematic review showed that recommended optimal decision-making time points were strongly correlated with the average implant time point of those individual studies (R = 0.96, P < 0.001). We further conducted modelling which revealed that in any such study, the ROC method is strongly biased to indicate a value near to the median time to implant as optimal.

CONCLUSION

When commonly used automated statistical methods are applied to observational data with the aim of defining the optimal time to pacing after cardiac surgery, the suggested answer is likely to be similar to the average time to pacing in that cohort.

The prevalence of permanent pacemaker implantation after open-heart surgeries; eight years of experience in Tehran heart center

BACKGROUND

We aimed to evaluate the prevalence of permanent pacemaker implantation (PPI) among open-heart surgery patients.

METHODS

We reviewed data from 23 461 patients undergoing open-heart surgeries between 2009 and 2016 in our heart center in Iran. A total of 18 070 patients (77%) had coronary artery bypass grafting (CABG), 3 598 (15.3%) valvular surgeries, and 1 793 (7.6%) congenital repair procedures. Finally, 125 patients who received PPI following open-heart surgeries were enrolled in our study. We defined the demographic and clinical characteristics of all these patients.

RESULTS

PPI was required in 125 (0.53%) patients with an average age of 58 ± 15.3 years. The average hospitalization time after surgery and waiting time for PPI were 19.7 ± 10.2 and 11.4 ± 6.5 days, respectively. Atrial fibrillation was the dominant pre-operative cardiac conduction abnormality (29.6%). Also, the primary indication for PPI was complete heart block in 72 patients (57.6%). Patients in the CABG group were significantly older (P = 0.002) and were more likely to be male (P = 0.030). The valvular group longer bypass and cross-clamp times and had more left atrial abnormalities. In addition, the congenital defect group was younger and had longer ICU stay times.

CONCLUSIONS

Based on our study findings, PPI was required in 0.53% of patients following open-heart surgery due to damage to the cardiac conduction system. The current study paves the way for future investigations to identify possible predictors of PPI in patients undergoing open-heart surgeries.

Techniques to aid prediction of pacing dependence at 30 days in patients requiring pacemaker implantation after cardiac surgery

Permanent pacemaker (PPM) implantation occurs in up to 5 % of patients after cardiac surgery but there is little consensus on how long to wait between surgery and PPM insertion. Predicting the likelihood of a patient being pacing dependent 30 days after implant can aid with this timing decision and avoid unnecessary observation time waiting for intrinsic conduction to recover. In this paper, we introduce a new approach for the prediction of PPM dependency at 30 days after implant in patients who have undergone recent cardiac surgery. The aim is to create an automatic detection model able to support clinicians in the decision-making process. We first applied Synthetic Minority Oversampling Technique (SMOTE) and Bayesian Networks (BN) to the dataset, to balance the inherently imbalanced data and create additional synthetic data respectively. The six resultant datasets were then used to train four different classifiers to predict pacing dependence at 30 days, all using the same testing set. The Bagged Trees classifier achieved the best results, reaching an area under the receiver operating curve (AUC) of 90 % in the train phase, and 83 % in the test phase. The overall classification performance was clearly enhanced when using SMOTE and synthetic data created with BN to create a combined and balanced dataset. This technique could be of great use in answering clinical questions where the original dataset is imbalanced.

Temporary epicardial pacing wires post-cardiac surgery: a literature review

BACKGROUND

Although epicardial pacing wires are routinely inserted after cardiac surgical procedures, there is little in the medical literature to help standardise their use and identify associated risks and benefits. Much of the decision-making surrounding pacing wires are based on the surgeon's preference and vary highly between centers.

METHODS

A literature review was conducted exploring the evidence, indications, and current practice for temporary pacing wires. Risk factors for developing post-operative arrhythmias necessitating use of temporary pacing wires and complications were also reviewed.

CONCLUSIONS

Although temporary epicardial pacing wires have a crucial role to play in the post-operative recovery period, the current literature suggests that they should be considered on an individual basis in all high-risk patients including increased age, low ejection fraction, diabetes mellitus, elevated pulmonary artery pressures, prolonged cross clamp time, pacing required to wean from bypass, pre-operative arrhythmia, and multiple valvular and transplant operations. Although complications from pacing wires are low, this figure is likely underreported and further studies are required to focus on the risks and benefits of insertion.

Mitral valvuloplasty with left atrial appendage closure and pacemaker implantation in a dog with severe myxomatous mitral valve degeneration: a case report

Background

Mitral valvuloplasty (MVP) has been widely recognized as a treatment option for myxomatous mitral valve disease (MMVD). However, postoperative complications such as thromboembolism, arrhythmia, and pancreatitis in some cases have resulted in death. We treated a dog with severe MMVD complicated by impaired sinus function with MVP and pacemaker implantation. Also, due to an intrinsic procoagulant state and severe arrhythmia after the MVP, left atrial appendage (LAA) closure was performed to reduce the postoperative risk of thrombosis.

Case presentation

An 11-year-old castrated 7.5-kg male Miniature Schnauzer with a history of congestive heart failure was brought to Shiraishi Animal Hospital for MMVD surgical treatment. Echocardiography revealed an enlarged left atrium and ventricle secondary to MMVD. Sinus arrest with 2 to 3-second periods of asystole was identified by electrocardiogram. Mitral valvuloplasty was performed with cardiopulmonary bypass to treat the MMVD. After coronary reperfusion, there was no spontaneous electrical activity. Cardiac arrest continued. Based on this surgical outcome, a permanent pacemaker was implanted. In addition, LAA closure with an AtriClip was performed to prevent intra-atrial thrombus formation. Cardiac remodeling and congestion were ameliorated after surgery. Sinus rhythm was restored 5 days postoperatively; however, the patient continued pacemaker dependent. All cardiac drugs were discontinued 3 months after surgery. The owner reported no postoperative complications (i.e., thrombosis), and the patient was brought for a check-up 4 months after the operation in good health.

Conclusions

For surgical MMVD cases complicated with impaired sinus function, the chances of spontaneous sinus rhythm are low, requiring pacemaker implantation. LAA closure may be considered to protect against decreased atrial function after mitral valvuloplasty and prevent intra-atrial thrombus formation.

Pre-operative Considerations in Adult Mucopolysaccharidosis Patients Planned for Cardiac Intervention

Mucopolysaccharidoses (MPS) are rare lysosomal storage diseases characterized by multiorgan involvement and shortened longevity. Due to advances in therapies such as enzyme replacement therapy and haematopoietic stem cell therapy, life expectancy has increased posing newer challenges to patients and health professionals. One such challenge is cardiovascular manifestations of MPS, which can be life limiting and cause reduction in quality of life. Any cardiovascular intervention mandates comprehensive, multi-systemic work-up by specialist teams to optimize outcome. We highlight the importance of multidisciplinary evaluation of adult MPS patients requiring cardiovascular intervention. Clinical assessments and investigations are discussed, with a focus on the cardiac, anesthetic, airway, respiratory, radiological and psychosocial factors.

Outcomes and periprocedural management of cardiac implantable electronic devices in patients with carcinoid heart disease

BACKGROUND

Carcinoid heart disease (CHD) is a rare complication of hormonally active neuroendocrine tumors that often requires surgical intervention. Data on cardiac implantable electronic device (CIED) implantation in patients with CHD are limited.

OBJECTIVE

The purpose of this study was to evaluate the experience of CIED implantation in patients with CHD.

METHODS

Patients with a diagnosis of CHD and a CIED procedure from January 1, 1995, through June 1, 2020, were identified using a Mayo Clinic proprietary data retrieval tool. Retrospective review was performed to extract relevant data, which included indications for implant, procedural details, complications, and mortality.

RESULTS

A total of 27 patients (55.6% male; mean age at device implant 65.6 ± 8.8 years) with cumulative follow-up of 75 patient-years (median 1.1 years; interquartile range 0.4-4.6 years) were included for analysis. The majority of implanted devices were dual-chamber permanent pacemakers (63%). Among all CHD patients who underwent any cardiac surgery, the incidence of CIED implantation was 12%. The most common indication for implantation was high-grade heart block (66.7%). Device implant complication rates were modest (14.8%). No patient suffered carcinoid crisis during implantation, and there was no periimplant mortality. Median time from implant to death was 2.5 years, with 1-year mortality of 15%.

CONCLUSION

CHD is a morbid condition, and surgical valve intervention carries associated risks, particularly a high requirement for postoperative pacing needs. Our data suggest that CIED implantation can be performed relatively safely. Clinicians must be aware of the relevant carcinoid physiology and take appropriate precautions to mitigate risks.

Self-rechargeable cardiac pacemaker system with triboelectric nanogenerators

Self-powered implantable devices have the potential to extend device operation time inside the body and reduce the necessity for high-risk repeated surgery. Without the technological innovation of in vivo energy harvesters driven by biomechanical energy, energy harvesters are insufficient and inconvenient to power titanium-packaged implantable medical devices. Here, we report on a commercial coin battery-sized high-performance inertia-driven triboelectric nanogenerator (I-TENG) based on body motion and gravity. We demonstrate that the enclosed five-stacked I-TENG converts mechanical energy into electricity at 4.9 μW/cm³ (root-mean-square output). In a preclinical test, we show that the device successfully harvests energy using real-time output voltage data monitored via Bluetooth and demonstrate the ability to charge a lithium-ion battery. Furthermore, we successfully integrate a cardiac pacemaker with the I-TENG, and confirm the ventricle pacing and sensing operation mode of the self-rechargeable cardiac pacemaker system. This proof-of-concept device may lead to the development of new self-rechargeable implantable medical devices.

Self-powered implantable devices have the potential to extend device operation, though current energy harvesters are both insufficient and inconvenient. Here the authors report on a commercial coin battery-sized high-performance inertia-driven triboelectric nanogenerator based on body motion and gravity that can be used to charge a lithium-ion battery and integrated into a cardiac pacemaker.

Impact of early (<7 days) pacemaker implantation after cardiac surgery on long-term pacemaker dependency

OBJECTIVE

We aimed to investigate pacemaker dependency after at least 1 year in patients with early (<7 days) implantation, compared to those who received a pacemaker ≥7 days after cardiac surgery. Secondary endpoints were length of hospital stay and in-hospital complications.

METHODS

Retrospective analysis of 108 consecutive patients who received a pacemaker after cardiac surgery between 06/2012 and 06/2018. Characteristics and outcomes were compared between patients with early (<7 days) and late (≥7 days) implantation. Patients were followed up with evaluation of pacemaker dependency between April and June 2019. We identified predictors of dependency by logistic regression.

RESULTS

In total, 63.9% were men, average age 71.9 ± 11.8 years; 32 (29.6%) had early implantation, and 76 (70.4%) late implantation. After a median 3.2 years [IQR 1.9, 4.5] of follow-up, 30 patients (27.8%) had died, and there was no difference in pacemaker dependency among survivors (66.7% vs. 46.5%, early vs. late respectively, p = .15). Patients in the early group had a shorter length of stay (11.5 [9.0, 14.0] vs. 15.0 [11.5, 20] days, p = .002) and less often had new-onset atrial fibrillation (AF) post-surgery (22.7% vs. 47.8%, p = .05). The only significant predictor of dependency was aortic valve replacement surgery (OR = 4.70, 95% CI [1.36 to 16.24]).

CONCLUSION

Early implantation of a permanent pacemaker (<7 days after cardiac surgery) does not impact on the proportion of patients with long-term (>12 months) pacemaker dependency, but is associated with shorter length of stay and less frequent new-onset AF. These findings warrant prospective confirmation in randomized trials.

Relation of Prolonged Pacemaker Dependency After Cardiac Surgery to Mortality

Permanent pacemaker implantation (PPI) represents a rare complication after cardiac surgery, with no uniform agreement on timing and no information on follow-up. A multicenter retrospective study was designed to assess pacemaker dependency (PMD) and long-term mortality after cardiac surgery procedures. Between 2004 and 2016, PPI-patients from 18 centers were followed. Time-to-event data were evaluated with semiparametric regression Cox models and semiparametric Fine and Gray model for competing risk framework. Of 859 (0.90%) PPI-patients, 30% were pacemaker independent (PMI) at 6 months. PMD showed higher mortality compared with PMI (10-year survival 80.1% ± 2.6% and 92.2% +2.4%, respectively, log-rank p-value < 0.001) with an unadjusted hazard ratio for death of 0.36 (95% CI 0.20 to 0.65, p< 0.001 favoring PMI) and an adjusted hazard ratio of 0.19 (95% CI 0.08 to 0.45, p< 0.001 with PMD as reference). Crude cumulative incidence function of restored PMI rhythm at follow-up at 6 months, 1 year and 12 years were 30.5% (95% CI 27.3% to 33.7%), 33.7% (95% CI 30.4% to 36.9%) and 37.2% (95% CI 33.8% to 40.6%) respectively. PMI was favored by preoperative sinus rhythm with normal conduction (SR) (HR 2.37, 95% CI 1.65 to 3.40, p< 0.001), whereas coronary artery bypass grafting and aortic valve replacement were independently associated with PMD (HR 0.63, 95% CI 0.45 to 0.88, p = 0.006 and HR 0.807, 95% CI 0.65 to 0.99, p = 0.047 respectively). Time-to-implantation was not associated with increased rate of PMI. Although 30% of PPI-patients are PMI after 6 months, PMD is associated with higher mortality at long term.

Predictors of Pacemaker Insertion Post-Sutureless (Perceval) Aortic Valve Implantation

INTRODUCTION

The use of rapid deployment sutureless aortic valve replacement (AVR) has become a viable alternative to conventional AVR especially in intermediate and high-risk patients. However, sutureless AVR has been associated with increased rates of permanent pacemaker (PPM) implantation compared with conventionally implanted aortic valve prostheses. The aim of this study was to determine predictive factors for complete heart block requiring insertion of a PPM post-AVR with a Perceval S sutureless valve (LivaNova, London, UK). Such knowledge will help to improve patient counselling, selection and management of patients undergoing sutureless AVR.

METHODOLOGY

A retrospective cohort study assessed all patients who underwent insertion of the Perceval sutureless aortic valve prosthesis between July 2015 and September 2019. Medical records were reviewed for demographic, preoperative electrocardiograph (ECG), and operative features related to postoperative PPM implantation and follow-up in the electrophysiology clinic.

RESULTS

One hundred and thirty (130) patients without pre-existing PPM underwent sutureless AVR (66.9% male, average age 74.4±6.6 years). Fifty-seven (57) underwent concomitant cardiac surgical procedures. Eight (8) patients underwent redo cardiac surgery. Nineteen (19) of the 130 (14.6%) patients required insertion of a PPM during their postoperative course. Factors associated with PPM insertion were right bundle branch block (overall n=15, PPM vs No PPM: 8/19 vs 7/111 [42.1 % vs. 6.31 %; p<0.01]), longer QRS duration 113.32ms±22.24 ms vs 100.52±20.96 ms (p=0.017) and longer PR Interval 185.166±42.38 ms vs 169.23±25.70 ms (p=0.03).

CONCLUSION

Insertion of rapid deployment sutureless aortic valves in the setting of pre-existing right bundle branch block, prolonged QRS complex and longer PR intervals is associated with increased risk of postoperative PPM requirement. These factors should be considered when preoperatively counselling and postoperatively managing patients when balloon expandable sutureless valves are used.

Indications and predictors for pacemaker implantation after isolated aortic valve replacement with bioprostheses: the CAREAVR study

OBJECTIVES

We sought to study the indications, long-term occurrence, and predictors of permanent pacemaker implantation (PPI) after isolated surgical aortic valve replacement with bioprostheses.

METHODS

The CAREAVR study included 704 patients (385 females, 54.7%) without a preoperative PPI (mean ± standard deviation age 75 ± 7 years) undergoing isolated surgical aortic valve replacement at 4 Finnish hospitals between 2002 and 2014. Data were extracted from electronic patient records.

RESULTS

The follow-up was median 4.7 years (range 1 day to 12.3 years). Altogether 56 patients received PPI postoperatively, with the median 507 days from the operation (range 6 days to 10.0 years). The PPI indications were atrioventricular block (31 patients, 55%) and sick sinus syndrome (21 patients, 37.5%). For 4 patients, the PPI indication remained unknown. A competing risks regression analysis (Fine-Gray method), adjusted with age, sex, diabetes, coronary artery disease, preoperative atrial fibrillation (AF), left ventricular ejection fraction, New York Heart Association class, AF at discharge and urgency of operation, was used to assess risk factors for PPI. Only AF at discharge (subdistribution hazard ratio 4.34, 95% confidence interval 2.34-8.03) was a predictor for a PPI.

CONCLUSIONS

Though atrioventricular block is the major indication for PPI after surgical aortic valve replacement, >30% of PPIs are implanted due to sick sinus syndrome during both short-term follow-up and long-term follow-up. Postoperative AF versus sinus rhythm conveys >4-fold risk of PPI.

CLINICAL TRIAL REGISTRATION

clinicaltrials.gov Identifier: NCT02626871.

Immediate outcome following valve surgery for rheumatic heart disease: the first local experience from Ethiopia

BACKGROUND

Rheumatic heart disease is the most common cardiac diseases in developing countries including Ethiopia. The current study aimed to describe the immediate surgical outcome following valve surgery for rheumatic heart disease in Ethiopia.

METHODS

Data were collected through chart abstraction from two centres in Addis Ababa, Ethiopia: the Cardiac Center of Ethiopia and El Ouzier cardiac centre. Included were all patients who were operated for rheumatic valvular heart disease in the mentioned centres by local cardiac surgical team during the period from June 2017 to April 2020. Demographic and clinical characteristics of the study population at admission and within 30 days of the index cardiac surgery were collected. Statistical Package for Social Sciences version 20.0 for windows was used to analyse the data.

RESULT

Of the 114 patients included in the study (median age 31 years with interquartile range of 23-40), 62 (54.4%) of them were female. Surgical procedures done were triple valve surgery 9 (7.9%) patients, mitral and tricuspid valves 26 (22.8%) patients, double-valve 16 (14.0%) patients, single-valve surgery 50.9% (11 aortic and 47 mitral valves) of patients, redo mitral valve surgery 3 (2.6%) patients, and left maze with mitral valve surgery 2 (1.8%) patients. Of the total, 103 (90.4%) of them had mitral valve surgery. Post-operatively, 5 (4.4%) patients died within 30 days following the index surgery.

CONCLUSION

Immediate surgical outcome following valve surgery for rheumatic heart disease had excellent outcome in our setting. This evidence can be taken as a show of success in building local capacity to manage rheumatic heart disease surgically.

Reduced Permanent Pacemaker Implantation in Patients With Stentless Freedom SOLO Compared With Stented Perimount Magna Aortic Bioprostheses: A Propensity Score Weighted Analysis

OBJECTIVES

Postoperative permanent pacemaker implantation (PPI) after conventional aortic valve replacement (AVR), due to new-onset severe conduction system disorders, is required in approximately 7% of patients. This study investigated the need for PPI after AVR with conventional stented Perimount Magna compared with the Freedom SOLO (FS) stentless valve (Sorin Group, Saluggia, Italy), now LivaNova plc (London, UK) that uses a strictly supra-annular, subcoronary running suture implantation technique, sparing the vulnerable interleaflet triangles in the region of the septum membranaceum.

METHODS

A total of 413 consecutive patients (71.4±9.2 yrs, 178 [43.1%] female) underwent isolated AVR using the stented Perimount Magna (n=264) or the stentless FS (n=149) bioprosthesis. Propensity score weighted analysis was used to account for patient-specific and procedural-specific variables, and to identify the prosthesis-specific need for early postoperative PPI within 30 days of AVR.

RESULTS

Twenty (20) patients required PPI, which was associated with longer intensive care unit (2.1±1.7 vs 1.5±3.0 days, p<0.001) and overall hospital stays (13.8±5.2 vs 10.7±5.3 days, p<0.001) compared with no PPI. Propensity weighted logistic regression including cross-clamp times identified that use of the stented Perimount Magna was associated with increased need for PPI, as compared with the FS, with an odds ratio 5.8 (95% CI, 1.09-30.76; p=0.039).

CONCLUSIONS

After corrections for all plausible confounders, AVR with the stented Perimount valve was associated with an odds ratio of almost 6 for an increased early postoperative need for pacemaker implantation compared with the FS stentless valve. This finding can be explained by the conventional implantation technique, which is potentially associated with mechanical trauma to the conducting system.

Localization of the sinoatrial and atrioventricular nodal region in neonatal and juvenile ovine hearts

Localization of the components of the cardiac conduction system (CCS) is essential for many therapeutic procedures in cardiac surgery and interventional cardiology. While histological studies provided fundamental insights into CCS localization, this information is incomplete and difficult to translate to aid in intraprocedural localization. To advance our understanding of CCS localization, we set out to establish a framework for quantifying nodal region morphology. Using this framework, we quantitatively analyzed the sinoatrial node (SAN) and atrioventricular node (AVN) in ovine with postmenstrual age ranging from 4.4 to 58.3 months. In particular, we studied the SAN and AVN in relation to the epicardial and endocardial surfaces, respectively. Using anatomical landmarks, we excised the nodes and adjacent tissues, sectioned those at a thickness of 4 μm at 100 μm intervals, and applied Masson's trichrome stain to the sections. These sections were then imaged, segmented to identify nodal tissue, and analyzed to quantify nodal depth and superficial tissue composition. The minimal SAN depth ranged between 20 and 926 μm. AVN minimal depth ranged between 59 and 1192 μm in the AVN extension region, 49 and 980 μm for the compact node, and 148 and 888 μm for the transition to His Bundle region. Using a logarithmic regression model, we found that minimal depth increased logarithmically with age for the AVN (R2 = 0.818, P = 0.002). Also, the myocardial overlay of the AVN was heterogeneous within different regions and decreased with increasing age. Age associated alterations of SAN minimal depth were insignificant. Our study presents examples of characteristic tissue patterns superficial to the AVN and within the SAN. We suggest that the presented framework provides quantitative information for CCS localization. Our studies indicate that procedural methods and localization approaches in regions near the AVN should account for the age of patients in cardiac surgery and interventional cardiology.

Epicardial pacing wires after cardiac surgery: an Irish cross-sectional study

BACKGROUND

Temporary epicardial pacing wires are inserted after cardiac surgery. However, there are no international guidelines on which to base best practice regarding wire insertion or removal.

METHODS

Data were collected on patients following cardiopulmonary bypass and analysed in terms of use, duration of use and complications of pacing wires after surgery.

RESULTS

Wires were inserted in 164 of the 167 patients. Most (74%) did not require pacing. Patients were categorised into those who had aortic valve replacement (AVR) (n=42) and those who did not (n=122). Of the AVR group, 26% (n=11) were pacemaker dependent after surgery and 10% (n=4) required permanent pacemakers. Most pacing wires were removed by day 4. The only noted complication was delayed discharge.

CONCLUSION

Unused pacing wires are normally removed on day 4, but for 77 (47%) of patients they remained in place longer. Forty patients (24%) had delayed wire removal because of a policy of wire removal during business hours only. Of these 40 patients, 27 (17% of the 77 with delayed removal) had delayed discharge as a result of our wire removal policy.

Permanent pacemaker implantation after cardiac surgery: Optimization of the decision making process

BACKGROUND

Conduction disturbances necessitating permanent pacemaker (PPM) implantation after cardiac surgery occur in 1% to 5% of patients. Previous studies have reported a low rate of late PPM dependency, but there is lack of evidence that it might be related to implantation timing. In this study, we sought to determine whether PPM implantation timing and specific conduction disturbances as indications for PPM implantation are associated with late pacemaker dependency and recovery of atrioventricular (AV) conduction.

METHODS

Patients with a PPM implanted after cardiac surgery were followed in an outpatient clinic. Two outcomes were assessed: AV conduction recovery and PPM dependency, defined as the absence of intrinsic rhythm on sensing test in VVI mode at 40 bpm.

RESULTS

Of 15,092 patients operated between September 2008 and March 2019, 185 (1.2%) underwent PPM implantation. One hundred seventy-seven of these patients met the criteria for inclusion into this study. Follow-up data were available in 145 patients (82%). Implantation was performed at ≤6 days after surgery in 58 patients (40%) and at >6 days after surgery in 87 patients (60%). The median time from implantation to last follow-up was 890 days (range, 416-1998 days). At follow-up, 81 (56%) patients were not PPM dependent. Multivariable analysis showed that PPM implantation at ≤6 days after surgery is a predictor of being not PPM dependent (odds ratio [OR], 5.40; 95% confidence interval [CI], 2.43-12.04; P < .001) and of AV conduction recovery (OR, 4.96; 95% CI, 2.26-10.91; P < .001). Sinus node dysfunction as indication for PPM implantation was predictive of being not PPM dependent (OR, 6.59; 95% CI, 1.67-26.06; P = .007).

CONCLUSIONS

We recommend implanting a PPM on postoperative day 7 to prevent unnecessary implantations and avoid prolonged hospitalization.

Incidence of permanent pacemaker implantation after valve replacement surgery : Cardiac structure and function at 1-year follow-up

BACKGROUND

Our study aimed to explore the incidence and risk factors of permanent pacemaker implantation (PPI) after valve replacement surgery (VR). The influence of long-term pacemaker dependency on cardiac structure and function at the 1‑year follow-up was also assessed.

METHODS

The demographic and surgical data of all consecutive patients who underwent VR between 2013 and 2016 were collected. Univariate and multivariate analyses were performed to identify variables independently associated with PPI after VR. A 1‑year follow-up was undertaken of patients who underwent dual-chambers pacemaker after VR because of complete atrioventricular block (AVB). Long-term pacemaker dependency and recovery of cardiac structure and function were evaluated.

RESULTS

There were 5320 consecutive patients with VR. The incidence of postoperative PPI was 2.42%. Multivariate analysis indicated that among the 62 patients who underwent PPI due to AVB and sick sinus syndrome, isolated aortic valve replacement (AVR; OR: 2.24, p < 0.05), VR combined with ventricular septal defect (VSD) repair (OR: 6.78, p < 0.05), and VR with aortic root and arch surgery (OR: 4.14, p < 0.05) were independent predictors of PPI after surgery. In total, 89.6% (43/48) of the survivors showed pacemaker dependency. Of these 43 patients, 24 had enlarged left heart before VR. Compared with preoperative values, the left atrial and left ventricular end-diastolic diameter post-PPI decreased significantly, while left ventricular ejection fraction was not significantly different.

CONCLUSION

Isolated AVR, VR concomitant with VSD repair, and VR with aortic root and arch surgery are independent predictors of PPI after VR. The majority of patients do not recover from AVB disorders and there is no significant negative effect on recovery of cardiac structure and function.

Predictors of pacing-dependency in patients with cardiovascular implantable electronic devices

BACKGROUND

Data on the prevalence and predictors for the development of pacing-dependency in patients with cardiovascular implantable electronic devices (CIEDs) are sparse.

METHODS

Pacing-dependency defined as an absence of intrinsic rhythm of ≥ 30 bpm was determined in 802 consecutive patients with CIEDs who visited the documented pacemaker or implantable cardioverter- defibrillator outpatient clinic for routine follow-up.

RESULTS

A total of 131 (16%) patients were found to be pacing-dependent 67 ± 70 months after CIED implant. Multivariate analysis revealed a significant association between pacing-dependency and the following clinical variables: second or third-degree atrioventricular (AV) block at implant (OR = 19.9; 95% CI: 10.9-38.5, p < 0.01), atrial fibrillation at implant (OR = 2.15; 95% CI: 1.16-4.05, p = 0.02), left ventricular ejection fraction (LVEF) ≤ 30% (OR = 2.06; 95% CI: 1.03-4.15, p = 0.04), B-type natriuretic peptide (BNP) > 150 pg/mL (OR = 2.12; 95% CI: 1.16-3.97, p = 0.02), chronic kidney disease (OR = 1.86; 95% CI: 1.08-3.26, p = 0.03), and follow-up duration after implantation > 5 years (OR = 3.29; 95% CI: 1.96-5.64, p < 0.01). None of the remaining clinical variables including age, gender, diabetes mellitus, underlying heart disease, prior cardiac surgery or medication during follow-up including betablockers and amiodarone predicted pacing-dependency.

CONCLUSIONS

Pacing-dependency is associated with second or third-degree AV-block at implant, atrial fibrillation before implant, low LVEF, elevated BNP, chronic kidney disease and follow-up duration after implant.

Anesthetic challenges in a pregnant patient with post mitral valve replacement, complete heart block, and coagulopathy coming for emergency cesarean section: A case report

A 24-year-old primigravida with a history of rheumatic heart disease and prosthetic mitral valve on oral anticoagulation who was lost follow-up during the third trimester presented with premature rupture of membranes. On evaluation, she had new-onset complete heart block. She was temporarily paced but developed cardiac failure. Anesthetic challenges and management of this parturient with post mitral valve replacement, complete heart block, and warfarin-induced coagulopathy for emergency cesarean delivery are discussed in this case report. Ours is the first case report of a pregnant patient with new onset of complete heart block during pregnancy several years after mitral valve replacement.

Bradyarrhythmia development and permanent pacemaker implantation after cardiac surgery

OBJECTIVE:

Bradyarrhythmia is one of the complications that may develop after cardiac surgery. Only a few studies have previously dealt with this concern, and in our study, we investigated the factors affecting the development of atrioventricular block or sinus node dysfunction and the requirement of permanent pacemaker following cardiac surgery.

METHODS:

A total of 62 patients who developed the atrioventricular (AV) block or sinus node dysfunction and required a permanent pacemaker following cardiac surgery were included in the study. Among these, 31 patients were evaluated prospectively, and the information regarding 31 patients was evaluated retrospectively based on hospital records. Demographic, clinical, and surgical information was recorded. Patients were grouped according to the types of procedures, including the coronary artery bypass graft, valve surgery, congenital heart disease, and combinations of these. Patients were evaluated by standard 12-lead electrocardiogram and transthoracic echocardiography preoperatively. The postoperative development of bradyarrhythmia and requirement of permanent pacemaker were evaluated.

RESULTS:

The mean age of patients with preoperative conduction abnormality and wide QRS was statistically significantly higher than those without these disorders. The odds ratio for preoperative conduction abnormality risk in patients over 70 years of age was found as 4.429 (95% confidence interval, 1.40–13.93). There was no gender-related statistically significant difference in terms of left ventricular ejection fraction, left ventricular dilatation, interventricular septum thickness, the time interval from operation to the development of AV block, concomitant diseases, and complication rates.

CONCLUSION:

Preoperative conduction abnormality and wide QRS in patients over 70 years of age was determined as a risk factor.

Frequency of Recovery from Complete Atrioventricular Block After Cardiac Surgery

Best timing for permanent pacemaker implantation to treat complete atrioventricular block (AVB) after cardiac surgery is unclear, as late pacemaker dependency was found low in recent observational studies. This study aimed to identify factors associated with spontaneous recovery from AVB. In a prospective and observational cohort, all patients who underwent cardiothoracic surgery during a 14-month-period were included (n = 1,200). Risk factors of postoperative AVB were assessed by logistic regression. Among patients who developed AVB, variables associated with recovery from AVB were assessed by Cox and logistic regression. Overall incidence of postoperative AVB was 6.0%. Risk factors of AVB were age (OR 1.03 [1.00 to 1.06], p = 0.023); female gender (OR 2.06 [1.24 to 3.41], p = 0.005), active endocarditis (OR 3.31 [1.33 to 8.26], p = 0.01), and aortic valve replacement (OR 3.17 [1.92 to 5.25], p <0.001). Among aortic valve replacement, sutureless aortic valve replacement was associated with more AVB (26.7% vs 8.1%, p <0.01). Recovery from AVB occurred in 30 patients (41.7%) in a median period of 3 days [interquartile range = 1;5]. Among patients who would recover from AVB, 90% of patients did so before day 7. None of the studied variable was independently associated with recovery from AVB. In conclusion, identified risk factors of postoperative AVB after cardiac surgery were age, female gender, endocarditis, and aortic valve replacement. Because most patients who would recover did so before day 7, this study validates modern guidelines suggesting permanent pacemaker implantation on day 7.

Assessment of the effect of left atrial cryoablation enhanced by ganglionated plexi ablation in the treatment of atrial fibrillation in patients undergoing open heart surgery

BACKGROUND

The aim of our study was to investigate, whether enhancement of left atrial cryoablation by ablation of the autonomic nervous system of left atrium leads to influencing the outcomes of surgical treatment of atrial fibrillation in patients with structural heart disease undergoing open-heart surgery.

METHODS

The observed patient file consisted of 100 patients, who have undergone a combined open-heart surgery at our department between July 2012 and December 2014. The patients were indicated for the surgical procedure due to structural heart disease, and suffered from paroxysmal, persistent, or long-standing persistent atrial fibrillation. In all cases, left atrial cryoablation was performed in the extent of isolation of pulmonary veins, box lesion, connecting lesion with mitral annulus, amputation of the left atrial appendage and connecting lesion of the appendage base with left pulmonary veins. Furthermore, 35 of the patients underwent mapping and radiofrequency ablation of ganglionated plexi, together with discision and ablation of the ligament of Marshall (Group GP). A control group was consisted of 65 patients without ganglionated plexi intervention (Group LA). The main primary outcome was establishment and duration of sinus rhythm in the course of one-year follow-up.

RESULTS

Evaluation of the number of patients with a normal sinus rhythm in per cent has shown comparable values in both groups (Group GP - 93.75%, Group LA - 86.67%, p = 0.485); comparable results were also observed in patients with normal sinus rhythm without anti-arrhythmic treatment in the 12th month (Group GP - 50%, Group LA - 47%, p = 0.306). We have not observed any relation between the recurrence of atrial fibrillation and the presence of a mitral valve surgery, or between the presence of a mitral and tricuspid valves surgery and between the left atrial diameter > 50 mm.

CONCLUSIONS

Enhancement of left atrial cryoablation by gangionated plexi ablation did not influence the outcomes of surgical ablation due to atrial fibrillation in our population in the course of 12-month follow-up.

TRIAL REGISTRATION

The study was approved retrospectively by the Ethics Committee of the University Hospital Ostrava ( reference number 867/2016).

Predictors of Permanent Pacemaker Implantation After Coronary Artery Bypass Grafting and Valve Surgery in Adult Patients in Current Surgical Era

Background

Permanent pacemaker (PPM) implantation after cardiac surgery is required in 0.4-6% of patients depending on cardiac surgery type. PPM implantation in the early postoperative period may reduce morbidity and postoperative hospital stay. We performed a retrospective review of electronic medical records of adult patients with coronary artery bypass grafting (CABG), valve surgery, or both, over a 3-year period. Our aim was to identify predictors of PPM requirements and PPM dependency on follow-up in the current surgical era.

Methods

After exclusion of patients with congenital heart disease, patients who already had a PPM or implantable cardioverter defibrillator (ICD), and patients with an indication for PPM or ICD before surgery, we identified 1,234 adult patients who underwent cardiac surgery between January 2007 and December 2009. A retrospective review of electronic medical records and pacemaker clinic data was performed.

Results

Patients’ mean age was 46.65 ± 16 years, and 59% were males. CABG was performed in 575 (46.6%) cases, aortic valve replacement in 263 (21.3%), mitral valve replacement in 333 (27%), and tricuspid valve replacement in 76 patients (6.2%). Twenty patients (1.6%) required implantation of a PPM postoperatively. Indications for PPM implantation included complete atrioventricular (AV) block in 13 (65%), sick sinus syndrome in three (15%), and atrial fibrillation (AF) with a slow ventricular rate in four (20%). Predictors for PPM requirement by multivariate analysis were the presence of pulmonary hypertension (P-HTN), reoperation, and left bundle branch block (LBBB) (P < 0.05). Late follow-up was available in 18 patients, at 84.5 ± 30 months. Eleven patients (61%) were PPM dependent on long-term follow-up.

Conclusions

Patients at high risk for PPM implantation after cardiac surgery include those with P-HTN, reoperation, and pre-existing LBBB. Of those receiving a PPM, about one-third will recover at least partially at long-term follow-up. We recommend preoperative assessment for risk of requiring postoperative PPM, to counsel patients about this risk and early PPM implantation in high-risk patients who are PPM dependent after surgery.

Pacemaker Dependency after Cardiac Surgery: A Systematic Review of Current Evidence

Background

Severe postoperative conduction disturbances requiring permanent pacemaker implantation frequently occur following cardiac surgery. Little is known about the long-term pacing requirements and risk factors for pacemaker dependency in this population.

Methods

We performed a systematic review of the literature addressing rates and predictors of pacemaker dependency in patients requiring permanent pacemaker implantation after cardiac surgery. Using a comprehensive search of the Medline, Web of Science and EMBASE databases, studies were selected for review based on predetermined inclusion and exclusion criteria.

Results

A total of 8 studies addressing the endpoint of pacemaker-dependency were identified, while 3 studies were found that addressed the recovery of atrioventricular (AV) conduction endpoint. There were 10 unique studies with a total of 780 patients. Mean follow-up ranged from 6–72 months. Pacemaker dependency rates ranged from 32%-91% and recovery of AV conduction ranged from 16%-42%. There was significant heterogeneity with respect to the definition of pacemaker dependency. Several patient and procedure-specific variables were found to be independently associated with pacemaker dependency, but these were not consistent between studies.

Conclusions

Pacemaker dependency following cardiac surgery occurs with variable frequency. While individual studies have identified various perioperative risk factors for pacemaker dependency and non-resolution of AV conduction disease, results have been inconsistent. Well-conducted studies using a uniform definition of pacemaker dependency might identify patients who will benefit most from early permanent pacemaker implantation after cardiac surgery.

Atrioventricular block in coronary artery bypass surgery: perioperative predictors and impact on mortality

Introduction

Disturbances of the cardiac conduction system are frequent in the postoperative period of coronary artery bypass surgery. They are mostly reversible and associated with some injury of the conduction tissue, caused by the ischemic heart disease itself or by perioperative factors.

Objective

Primary: investigate the association between perioperative factors and the emergence of atrioventricular block in the postoperative period of coronary artery bypass surgery. Secondary: determine the need for temporary pacing and of a permanent pacemaker in the postoperative period of coronary artery bypass surgery and the impact on hospital stay and hospital mortality.

Methods

Analysis of a retrospective cohort of patients submitted to coronary artery bypass surgery from the database of the Postoperative Heart Surgery Unit of the Sao Lucas Hospital of the Pontifical Catholic University of Rio Grande do Sul, using the logistic regression method.

Results

In the period from January 1996 to December 2012, 3532 coronary artery bypass surgery were carried out. Two hundred and eighty-eight (8.15% of the total sample) patients had atrioventricular block during the postoperative period of coronary artery bypass surgery, requiring temporary pacing. Eight of those who had atrioventricular block progressed to implantation of a permanent pacemaker (0.23% of the total sample). Multivariate analysis revealed a significant association of atrioventricular block with age above 60 years (OR=2.34; CI 95% 1.75-3.12; P<0.0001), female gender (OR=1.37; CI 95% 1.06-1.77; P=0.015), chronic kidney disease (OR=2.05; CI 95% 1.49-2.81; P<0.0001), atrial fibrillation (OR=2.06; CI 95% 1.16-3.66; P=0.014), functional class III and IV of the New York Heart Association (OR=1.43; CI 95% 1.03-1.98; P=0.031), perioperative acute myocardial infarction (OR=1.70; CI 95% 1.26-2.29; P<0.0001) and with the use of the intra-aortic balloon in the postoperative period of coronary artery bypass surgery (OR=1.92; CI 95% 1.21-3.05; P=0.006). The presence of atrioventricular block resulted in a significant increase in mortality (17.9% vs. 7.3% in those who did not develop atrioventricular block) (OR=2.09; CI 95% 1.46-2.99; P<0.0001) and a longer hospital stay (12.75 days x 10.53 days for those who didn't develop atrioventricular block) (OR=1.01; CI 95% 1.00-1.02; P=0.01).

Conclusions

In most cases, atrioventricular block in the postoperative period of coronary artery bypass surgery is transient and associated with several perioperative factors: age above 60 years, female sex, chronic kidney disease, atrial fibrillation, New York Heart Association functional class III or IV, perioperative acute myocardial infarction and use of an intra-aortic balloon. Its occurrence prolongs hospitalization and, above all, doubles the risk of mortality.

Valvular heart disease and postoperative considerations

Despite increasing trends in catheter-based cardiac surgical procedures, more than 278 000 Americans had traditional cardiac surgery in 2013. Of those surgical procedures, approximately 133 000 involved valvular repair or replacement. Aortic valve replacement was by far the most common valvular operation, followed by mitral valve repair or replacement. This review article will discuss characteristics of valvular pathologies and postoperative concerns for each the 4 cardiac valves.

Conversion of hemiblock to complete heart block by intraoperative motor-evoked potential monitoring

Intraoperative monitoring of nervous system pathways, including assessing the integrity of descending motor pathways with motor-evoked potentials, is often performed in intracranial and spine operations to reduce the risk of iatrogenic neurological impairment. We present a case in which intraoperative monitoring with motor-evoked potentials resulted in complete heart block in a patient with a history of hemiblock. Neuromonitoring has been associated with arrhythmias in patients with ostensibly normal conduction systems, and we propose that monitoring personnel, anesthesiologists, and surgeons need to be aware of this risk and exercise caution when monitoring motor-evoked potentials in patients with known conduction deficits.