Heart Rate Variability and Its Role in Predicting Atrial Fibrillation in Patients Undergoing Coronary Artery Bypass Graft.

Background: An association between heart rate variability (HRV) and cardiac events in certain diseases has been demonstrated. However, the association with new-onset atrial fibrillation (AF) after coronary artery bypass grafting (CABG) is still controversial. This study aimed to investigate the association between HRV and new-onset AF in patients undergoing CABG during a 6-month follow-up. Methods: This prospective study included 119 consecutive patients who underwent off-pump CABG. All patients were assessed using 24-hour Holter recordings 2 days before CABG and 1 week, 3 months, and 6 months postoperatively. HRV was analyzed, and AF was detected from its recordings. Main results: In patients undergoing CABG, NYHA III increased the AF rate 7 days postoperatively, and advanced age and diabetes were associated with AF 6 months postoperatively. A reduction in time-domain measurements before surgery was significantly associated with a higher risk of developing AF seven days postoperatively; no association between preoperative HRV and AF was found at six months. Reduced preoperative HRV (SDNN (standard deviation of all normal-to-normal intervals [) < 50 ms) was an independent predictor of AF at 3 (AUC = 0.65) and 6 months (AUC = 0.62) following surgery. Conclusion: A reduction in the time domain measurements before CABG was associated with a higher risk of new-onset AF at 7 days postoperatively but not at 6 months. An SDNN <50 ms was a weak independent predictor of a higher incidence of AF at 3 and 6 months post-surgery.

Pattern Changes in the Heart Rate Variability of Patients Undergoing Coronary Artery Bypass Grafting Surgery.

Introduction: Coronary artery bypass grafting (CABG) with extracorporeal circulation is a key therapy for coronary artery disease (CAD). However, cardiovascular events and cardiac arrhythmias may still occur in these patients following surgery. Many studies have demonstrated a correlation between cardiac arrhythmias and heart rate variability (HRV). This study aimed to establish the temporal change pattern of HRV observed following CABG. Methods: A prospective method was used to study 119 consecutive patients with stable CAD who were assessed using 24-hour Holter recordings 2 days before CABG and 1 week, 3 months, and 6 months after the surgery at Hanoi Heart Hospital from June 2016 to August 2018. Main results: All the time-domain and frequency-domain parameters of HRV decreased precipitately after CABG and were mostly recovered 3 months postoperatively. The percentage of decreased HRV before surgery was 28.6% and 51.8% after 7 days, 19.6% after 3 months, and 12.7% after 6 months. ASDNN and SDNN before and after surgery had the highest rates of change. Conclusion: The early decrease in HRV observed 7 days after CABG may be related to the acute effects of the surgery. The recovery of HRV at 3 months after surgery, regardless of the preoperative state of the patients, implies that the autonomic nervous system (ANS) disorder may be improved at this time. At 6 months after surgery, the autonomic nervous injury was recovered in combination with improvement of reperfusion, resulting in improvement in almost all HRV indices compared with those indices preoperatively.

Factors Associated with Early Postoperative Results of Total Anomalous Pulmonary Venous Connection Repair: Findings from Retrospective Single-Institution Data in Vietnam.

INTRODUCTION: There are scanty reports of the risk factors for pulmonary hypertensive crisis and low cardiac output syndrome after the operative repair of total anomalous pulmonary venous connection (TAPVC). We aim to evaluate early surgical outcomes of TAPVC and risk factors for pulmonary hypertensive crisis and low cardiac output syndrome. METHODS: We conducted a retrospective medical record review for all patients undergoing operative repair of TAPVC within 5 years. Outcome variables included pulmonary hypertensive crisis, low cardiac output syndrome and early mortality. RESULTS: Of 58 patients, we documented 77.59% supracardiac, 20.69% cardiac and 1.72% mixed site of connection. About 86.21% patients underwent elective surgery, and 13.79% patients required emergency surgery. Incidence rates were 27.59% for pulmonary hypertensive crisis and 6.90% for low cardiac output syndrome. Body weight below 6 kg, pneumonia, tachycardia, hepatomegaly, preoperative pulmonary congestion on chest x-ray, preoperative elevated mean pulmonary artery pressure, preoperative pulmonary venous obstruction, emergency surgery and prolonged aortic cross-clamping time were significant risk factors for postoperative pulmonary hypertensive crisis. Significant risk factors for postoperative low cardiac output syndrome included pneumonia, prolonged duration of preoperative mechanical ventilation and prolonged aortic cross-clamping time. CONCLUSION: The early outcome of surgical repair of TAPVC was acceptable, with 96.55% survival rate. This current analysis suggests that a thorough evaluation of all preoperative and operative characteristics is imperative to achieve best medical and surgical outcomes.

Impact of Pre-, Intra-and Post-Operative Parameters on In-Hospital Mortality in Patients Undergoing Emergency Coronary Artery Bypass Grafting: A Scarce Single-Center Experience in Resource-Scare Setting.

BACKGROUND: In-hospital mortality after emergency coronary artery bypass grafting (CABG) remains an important issue that has needed considerable attention in recent years as the mortality rate is still high and prevention factors are not yet optimal. Our study presents the first largest cohort of emergency CABG from one large institution in Vietnam with the primary aim of comparing a large variety of pre-, intra-and post-operative parameters between in-hospital mortality patients and in-hospital survival patients and investigate risk factors of in-hospital mortality in patients undergoing emergency CABG. METHODS: We conducted a retrospective evaluation of prospectively collected data in patients undergoing emergency CABG at the Hanoi Heart Hospital (Hanoi, Vietnam) from January 1, 2017, to December 31, 2019. Primary outcome variable was in-hospital mortality. RESULTS: A total of 71 patients were included in final analysis. The mean age of the cohort was 68.68 years (± 9.28, range 38-86). The mean weight, height and body mass index were 54.35 kg (± 9.17, range 37-77), 158.96 (±7.64, range 145-179) and 21.48 kg/m2 (±3.08, range 13.59-30.08), respectively. In-hospital mortality rate was 9.86%. Preoperative risk factors for in-hospital mortality included diabetes, decreased ejection fraction (EF), EF below 30%, cardiogenic shock, elevated systolic pulmonary artery pressure (PAP), elevated NT-ProBNP, and Euroscore II. Without grafting with left internal thoracic artery, and prolonged cardiopulmonary bypass (CPB) time were increased intraoperative factors for in-hospital mortality risk. In-hospital mortality's postoperative risk factors were found to be postextubation respiratory failure requiring mechanical ventilation, ventricular fibrillation, dialysis-requiring acute renal failure, pneumonia, bacterial sepsis, gastrointestinal bleeding, and prolonged mechanical ventilation time. Significant predictors determining in-hospital mortality were known as prolonged CPB time in surgery and postoperative ventricular fibrillation. CONCLUSION: Our hospital mortality rate after emergency CABG was relatively high. An optimal preventive strategy in emergency CABG management should target significant factors combined with other previously identified risk factors to reduce in-hospital mortality.