A case of new onset of atrial fibrillation during thoracoscopic lobectomy and review of the literature

Abstract

Background

Atrial fibrillation (AF) is a prevalent perioperative complication associated with lung surgery, contributing to an elevated risk of adverse postoperative outcomes. However, instances of new-onset intraoperative Atrial fibrillation (IOAF) remain infrequently documented. In this report, we present a case of intraoperative new-onset atrial fibrillation occurring during thoracoscopic partial lung resection. Additionally, we examine the risk factors, preventive strategies, and therapeutic interventions for atrial fibrillation, with the objective of enhancing prevention and management of this condition in the perioperative setting.

Case presentation

A 71-year-old female patient was scheduled to undergo a thoracoscopic left upper lobectomy due to a ‘left upper lung mass.’ Preoperative electrocardiogram showed occasional atrial premature beats, and cardiac ultrasound indicated left ventricular diastolic dysfunction. During the intraoperative dissection of the hilar lymph nodes, the patient suddenly developed rapid atrial fibrillation with a heart rate of 113 beats per minute, accompanied by pulse deficit. Immediately suspend the surgical operation, but after intravenous administration of dexmedetomidine, the patient’s rhythm did not convert to sinus rhythm, and hemodynamic instability occurred. After stabilizing blood pressure with vasoactive drugs, intravenous amiodarone was given to control the ventricular rate. The patient was transferred to the ICU postoperatively and successfully restored sinus rhythm after subsequent amiodarone treatment.

Conclusions

New-onset atrial fibrillation during surgery is a complication that requires attention in thoracic surgery. The novelty of this report lies in: (1)providing a detailed description of the negative clinical experience in which dexmedetomidine was ineffective in this scenario and led to hemodynamic instability, contrasting with previous case reports; (2) proposing a pragmatic strategy of controlling heart rate during surgery and delaying cardioversion until after surgery; (3)emphasizing that elderly women, left lung lobe resection (involving hilar lymph node dissection), and preoperative diastolic dysfunction should also be considered as potential risk factors.

Background

This study reports a case of a 71-year-old female patient who developed new-onset atrial fibrillation during mediastinal lymph node dissection in a thoracoscopic left upper lobectomy, and, combined with a literature review, explores the risk factors, prevention and treatment strategies, and research controversies of IOAF.

Atrial fibrillation(AF) is the most common arrhythmia in thoracic surgery patients during the perioperative period. The incidence of postoperative atrial fibrillation after lung resection ranges from 8% to 46%, while the intraoperative incidence is 1.2%–3.4% [1–2]. Although atrial fibrillation alone is rarely fatal, it can still lead to many adverse outcomes, such as hemodynamic instability, prolonged ICU or hospital stays, and even associations with stroke and death in patients [3]. It should be emphasized that currently, the vast majority of studies focus on atrial fibrillation occurring from the 2nd to the 7th day after surgery, which is primarily attributed to systemic inflammatory response, sympathetic nerve activation, and decreased cardiopulmonary reserve, and corresponding management guidelines have been established [4]. However, new-onset atrial fibrillation during surgery, due to its sudden occurrence, different mechanisms (mainly induced by mechanical surgical stimulation), and a very narrow treatment window, remains a challenge in anesthesia management and lacks dedicated clinical guidelines or consensus [5].

Currently, studies on new-onset atrial fibrillation during surgery are mostly single-center and small-sample studies, and their conclusions show significant heterogeneity [6–8]. Against this background, each high-quality case report of intraoperative atrial fibrillation may provide valuable real-world data for subsequent research and clinical practice. This article reports a case of new-onset atrial fibrillation during thoracoscopic lobectomy and reviews related literature to explore the risk factors, prevention and treatment strategies, and research controversies of new-onset atrial fibrillation during surgery, and to share the negative experience of using dexmedetomidine in this context.

Case presentation

A 71-year-old female patient, with a height of 153 cm and a weight of 49.5 kg, classified as American Society of Anesthesiologists (ASA) Physical Status II, underwent a thoracoscopic left upper lobectomy combined with hilar and mediastinal lymph node dissection to address a space-occupying lesion in the left upper lobe.The patient was in good physical condition with no prior history of cardiovascular disease. Preoperative ambulatory electrocardiogram results indicated the presence of sinus arrhythmia and episodic atrial premature beats. Cardiac ultrasound findings revealed mild mitral and tricuspid regurgitation, normal systolic function of the left ventricle, and impaired diastolic function. Prior to the administration of anesthesia, the patient’s blood pressure was recorded at 162/94 mmHg, with a heart rate of 76 beats per minute, sinus rhythm, and an oxygen saturation level of 98%. Ten minutes preceding the induction of anesthesia, the patient received 0.03 mg of pentoxyverine hydrochloride. Anesthesia was induced using propofol at a dosage of 1.5 mg/kg, cisatracurium at 2 mg/kg, and sufentanil at 0.04 µg/kg. Following induction, radial arterial and deep venous catheterizations were performed.During the surgical procedure, anesthesia was maintained using a combination of propofol, remifentanil, and sevoflurane. The dosages of these agents were adjusted in response to intraoperative stimuli. During the surgery, the surgeon performed a systematic lymph node dissection according to standard procedures. After successfully completing the left upper lobectomy and mediastinal lymph node (stations 5 and 7) dissection, the surgeon began addressing the left hilar lymph nodes (station 10). These lymph nodes were adjacent to the root of the left inferior pulmonary vein and the pericardium, with dense adhesions to the wall of the left atrium. While the surgeon was dissecting the lymph nodes, the patient suddenly developed rapid atrial fibrillation, with a heart rate of 113 beats per minute and a pulse of 80 beats per minute (Fig. 1). Following the anesthesiologist’s request for the surgeon to pause hilar lymph node dissection, the patient’s condition remained unimproved. Subsequently, a rapid intravenous infusion of dexmedetomidine at a dose of 20 µg was administered, which failed to ameliorate the situation, and the patient’s blood pressure began to decline. Consequently, norepinephrine was administered at a rate of 0.05 µg/kg/min to stabilize the blood pressure. Once the blood pressure was stabilized, the patient’s vital signs improved, and the ventricular rate decreased; however, atrial fibrillation persisted.Following surgery, the patient was transferred to the intensive care unit (ICU). Subsequent administration of amiodarone resulted in the restoration of the patient’s heart rate to sinus rhythm, with a reduction to 75 beats per minute and return to sinus rhythm.

Fig. 1.

Anesthesia Sheet (Upper red arrow: instantaneous heart rate during AF onset. Lower red arrow: concurrent pulse rate.)

Discussion and conclusion

This study reports a case of a 71-year-old female patient who developed new-onset atrial fibrillation during hilar lymph node dissection in thoracoscopic left upper lobectomy, and, combined with a literature review, explores the risk factors, prevention and treatment strategies, and research controversies of intraoperative new-onset atrial fibrillation.

AF represents a prevalent complication following thoracoscopic pulmonary resection, and its occurrence is intricately linked to several factors. These include advanced age (greater than 60 years), elevated preoperative resting heart rate (exceeding 72 beats per minute), pre-existing cardiac and pulmonary conditions, alterations in autonomic function, inflammatory responses, surgically induced trauma, and the extent of surgical resection [5–8]. However, the risk factors for new-onset IOAF differ from those for perioperative atrial fibrillation (Table 1). A study identified advanced age, male gender, and the extent of surgical resection as independent risk factors for intraoperative atrial fibrillation [2].Elderly patients exhibit diminished pulmonary reserve, heightened comorbidities, and increased tissue fragility, in conjunction with age-associated myocardial apoptosis and fibrosis. These factors may contribute to cardiac remodeling, delayed intra-atrial conduction, and increased susceptibility of nerve impulses to refracture within the atria, thereby predisposing them to atrial fibrillation [2]. Additionally, the incidence of atrial fibrillation is higher in men compared to women, potentially due to the larger cardiac size in men, which may elicit a more pronounced pro-inflammatory response and result in reduced post-traumatic cardioprotection relative to women [9]. he elevated incidence of intraoperative atrial fibrillation observed in lobectomy, as opposed to thoracoscopic segmental lung resection, may be attributed to the greater number of lymph nodes requiring dissection, the more extensive resection of critical tissues, and the heightened risk of.

Table 1.

High-risk factors for perioperative new-onset atrial fibrillation and high-risk factors for intraoperative new-onset atrial fibrillation

High-risk factors for new-onset perioperative atrial fibrillation			Unique high-risk factors for new-onset intraoperative Atrial fibrillation
The patient’s condition	Elderly people Male Malignant tumor Hypertension Preoperative baseline heart rate is fast (> 72 beats/min) Congestive heart failure Coronary heart disease, as well as preoperative cardiac anatomical abnormalities and electrophysiological abnormalities, etc. Smoking or lung dysfunction	[5,13] [5] [14] [6,14] [5] [6] [6, 14] [6, 14]	Elderly people Male Diabetes Diameter of the lesion	[2] [2] [2] [2]
Surgical factors	The scope of surgical excision Open surgery Surgery time	[14, 15] [14] [11]	The scope of surgical excision Lymph node involvement and right lung resection	[2] [2,7]

vagal nerve injury [10, 11]. Additional potential risk factors for intraoperative atrial fibrillation, as identified in other studies, include diabetes mellitus, lesion diameter, clinical lymph node involvement, and right-sided pneumonectomy [2]. The elevated incidence of intraoperative atrial fibrillation associated with diabetes mellitus can be attributed to autonomic neuropathy, which impairs parasympathetic nerve function, thereby relatively enhancing sympathetic nerve activity [11]. In cases of inflammation at the lesion site, extensive tumor foci, and lymph node involvement, the vagus nerve and its branches may be obscured, complicating dissection and increasing the risk of injury. This risk is particularly pronounced in right-sided pneumonectomies, especially during the dissection of lymph nodes in the pulmonary venous plexus and the central venous plexus [11, 12].

This case is a 71-year-old female patient who underwent a left upper lobectomy. Intraoperatively, atrial fibrillation was triggered during the dissection of the hilar lymph nodes. From the perspective of risk factors: this patient meets the common risk factor of advanced age (71 years) for postoperative and intraoperative atrial fibrillation; she also meets the common risk factor of lobectomy; intraoperatively, there was clinically significant lymph node involvement (dissection of the hilar lymph nodes), which is a unique risk factor for intraoperative atrial fibrillation. However, the patient is female (literature shows males have a higher risk), had preoperative occasional atrial premature beats and left ventricular diastolic dysfunction, and underwent left-sided lung resection (literature shows right-sided procedures carry a higher risk), indicating that the existing risk factor models are not perfect. Patients who are female, have preexisting latent cardiac structural or functional abnormalities, or undergo left-sided lobectomy still require clinical vigilance and should not have intraoperative monitoring relaxed due to being considered ‘low risk.’

There are significant differences in the mechanisms of new-onset atrial fibrillation during surgery and postoperatively [1]. The formation of postoperative atrial fibrillation is mainly related to reduced cardiopulmonary reserve, a diminished systemic inflammatory response to surgery, and increased sympathetic nervous system activity [16]. In contrast, the main trigger for intraoperative atrial fibrillation is direct mechanical stimulation, especially manipulation near the cardiac plexus and pulmonary veins [1]. In this case, during the dissection of the left hilar lymph nodes, the mechanical traction from the separation procedure likely stimulated the neural plexus around the atria, which may be the main cause of intraoperative atrial fibrillation.

IOAF is predominantly attributed to mechanical stimulation resulting from surgical procedures. It has been proposed that this form of AF exhibits a poor response to pharmacological interventions, with β-blockers, the first-line recommended treatment for AF, demonstrating greater efficacy in managing new-onset AF [1, 17]. This enhanced efficacy may be attributed to the β-blockers’ capacity for appropriate rate control, which suppresses cardiac sympathoadrenergic tone and balances sympathetic and vagal tone [18]. However, it has also been suggested that the intraoperative use of pharmacological cardioversion for new-onset AF may influence hemodynamic stability [19, 20].Prophylactic use of amiodarone can reduce the incidence of postoperative atrial fibrillation after pulmonary resection [21, 22]. Wu et al.‘s study found that intraoperative use of amiodarone did not affect the rate of restoration of sinus rhythm in newly developed atrial fibrillation during surgery, but it might shorten the time to sinus rhythm recovery postoperatively [23]. Our report is similar, as patients did not restore sinus rhythm during surgery with the use of amiodarone, but recovered after postoperative amiodarone treatment. We speculate that the lack of amiodarone effect may be due to continuous mechanical stimulation during surgery. In a sense, the amiodarone effect is masked during surgery. The absence of surgical stimulation postoperatively allows amiodarone to exert its therapeutic effect. This phenomenon suggests that in the management of newly developed atrial fibrillation during surgery, controlling the ventricular rate might be a more realistic goal intraoperatively, while restoration of sinus rhythm can safely be pursued postoperatively.Electrical cardioversion is commonly employed in the management of atrial fibrillation; however, it is often conducted in the post-anesthesia care unit (PACU) due to intraoperative limitations and the fact that the patient has not yet fully recovered from anesthesia and remains intubated A single-center retrospective analysis demonstrated that electrical cardioversion performed in the PACU successfully restored sinus rhythm in over 98% of patients [1]. Dexmedetomidine, a highly selective α2-adrenergic agonist, has been shown to attenuate sympathetic activity affecting heart rate, sinus node function, and atrioventricular node conduction. Its use has been associated with a decreased incidence of new-onset atrial fibrillation in the critical care management of patients in intensive care units (ICUs) [24]. There are also reports suggesting that dexmedetomidine can be used as an alternative drug under conditions where other medications, such as β-blockers or amiodarone, poorly control ventricular rate [25]. However, the observations in this case differ significantly from the aforementioned literature.In this study, we administered 20 µg of dexmedetomidine immediately following the onset of atrial fibrillation and observed that its impact on heart rate was minimal. However, it induced blood pressure instability. This phenomenon may be related to the peripheral vascular α2 receptor agonist effect of dexmedetomidine. At high concentrations or with rapid administration, its peripheral α2 effects may activate presynaptic α2 receptors, providing negative feedback to inhibit norepinephrine release, leading to vasodilation and blood pressure reduction, which to some extent counteracts its central inhibitory effect on heart rate [26]. This phenomenon suggests that in acute sympathetic excitation states such as newly onset atrial fibrillation, the cardiovascular effects of dexmedetomidine may be complex and non-selective, and relying solely on it to control heart rate requires caution regarding the risk of hemodynamic instability. Currently, there is a lack of unified clinical guidelines or consensus for the treatment of intraoperative newly onset atrial fibrillation, and existing evidence mainly comes from the extension of postoperative atrial fibrillation management experience. However, after atrial fibrillation occurs, eliminating hidden risk factors, maintaining stable blood pressure, and controlling heart rate are key aspects of intraoperative management.

This report has the following limitations: First, it is a single case, so the generalizability of the observations is limited; second, although continuous electrocardiographic monitoring was used postoperatively, more detailed cardiac rhythm analysis was not conducted.

New-onset atrial fibrillation during surgery is an uncommon but highly concerning complication during thoracoscopic lobectomy. The main contributions of this report are: (1) presenting negative clinical evidence that dexmedetomidine was ineffective for new-onset atrial fibrillation during surgery and may exacerbate hemodynamic instability, which serves as an important supplement to previous case reports; (2) proposing a pragmatic management strategy during surgery that focuses on controlling the ventricular rate, with cardioversion postponed to the postoperative period; (3)suggesting that elderly women, left lung resection (involving hilar lymph node dissection), and preoperative diastolic dysfunction should also be included in the risk assessment for new-onset atrial fibrillation during surgery. Strengthening the identification of high-risk patients before surgery, maintaining vigilance during surgery, and establishing a rapid and organized management process are key to optimizing perioperative care and improving outcomes. In the future, multicenter, large-scale studies are needed to establish specialized risk assessment models and treatment guidelines for new-onset atrial fibrillation during surgery.

Abbreviations

ASA

Anesthesiologists

AF

Atrial fibrillation

IOAF

Intraoperative Atrial fibrillatio

ICU

Intensive care unit

PACU

Post-anesthesia care unit

Author contributions

Yuefen Zuo was responsible for the administration of anesthesia and writing of the article, Yanping Yang and Guangming Liang were responsible for the guidance of anesthesia, and Zhijun Wei and Xianping Wu were responsible for the guidance of review and revision of the complex article.

Funding

None.

Data availability

No datasets were generated or analysed during the current study.

Declarations

Ethics approval and consent to participate

Written consent obtained.

Consent for publication

Written consent obtained.

Competing interests

The authors declare no competing interests.