LAUSR

Atrial fibrillation (AF) is the most common arrhythmia with a prevalence ranging from 2% to 4% in the adult population. In addition to increasing the risk of mortality, it also causes socioeconomic problems by causing morbid consequences such as heart failure and stroke. Postoperative atrial fibrillation (PoAF) is a frequent complication ranging from 10% to 60% after major surgical interventions (cardiac surgery, pulmonary thromboendarterectomy [PTE], aortic surgery, etc.) requiring cardiopulmonary bypass (CPB). Its prevalence varies depending on the type and technique of surgery, patient characteristics, arrhythmia surveillance method, and the definition of arrhythmia. It is very important to reveal the risk factors and predictors of PoAF because it prolongs hospitalizations and increases the risk of mortality. PTE is the therapeutic modality of choice in chronic thromboembolic pulmonary hypertension (CTEPH). In patients undergoing PTE, postoperative complications including pleural effusion, bleeding, atrial arrhythmias and wound infection are similar to other cardiac surgery interventions. In this issue of the Journal of Cardiac Surgery , in a retrospective study by Liu et al., the impact of preoperative resting heart rate (RHR) on PoAF was investigated in patients who underwent elective PTE surgery for CTEPH. In this study, which included 97 patients, PoAF developed in 21 (21.6%) patients, and they showed preoperative RHR as an independent predictor of PoAF (odds ratio [OR] = 1.043, 95% confidence interval [CI]: 1.009–1.078, p = .012). However, this result had low predictive power (sensitivity: 47.6%, specificity: 77.6%). One of the most important problems in studies investigating PoAF risk factors after cardiothoracic surgical operations is the diagnosis of PoAF. In some studies, continuous telemetry recording was taken in the postoperative period, but in most studies, continuous electrocardiogram (ECG) follow‐up is not performed after the second postoperative day. If no symptoms related to AF occur in patients who are not followed up continuously, the diagnosis may be missed in some patients. Therefore, this situation reduces the value of the studies. Liu et al. have been increased the importance of their studies by performing continuous ECG monitoring in the postoperative period. RHR is an easily accessible physiological predictor that reflects the autonomic nervous system activity. It is also a well‐recognized predictor of morbidity and mortality in the general population. The relationship between RHR and the incidence of AF is controversial. Two large independent cohort studies from the Copenhagen Electrocardiographic Study and theTromsø Study found that a low RHR was considered an independent predictor of AF. In contrast, the results of another study showed that low RHR was not a significant risk factor for AF. High RHRs can increase hemodynamic stress and shorten the diastolic phase, thereby increasing blood pressure, cardiac workload, and oxygen consumption, resulting in myocardial ischemia. In a dose‐response meta‐analysis, it has been suggested that there was a significant J‐ shaped association between the RHR and AF. The authors also reported that both low RHR and high RHR were associated with an increased risk of AF compared with a modest RHR of 68–80 bpm. The development of PoAF can be affected by preoperative RHR, as demonstrated in this study by Liu et al. RHR is a marker of the autonomic nervous system. After autonomic activation, beta adrenergic stimulation can develop and PoAF can be triggered. This is where beta receptor blockers show effectiveness. The amiodarone is also an effective therapeutic agent in the preventing of PoAF, and in a meta‐analysis that included six studies, its effectiveness was found to be equivalent to the use of beta‐blockers. For all these reasons,