“Ping-pong” in the heart: a case report and literature review

Abstract

Background

Ball thrombus is rare and life-threatening. The correct diagnosis and timely management are key to improving patient prognosis. Here, we present a case report and literature review of ball thrombus.

Case presentation

A 75-year-old woman presented to our outpatient clinic because of palpitations and chest distress for 8 months. She was diagnosed mitral stenosis, and transthoracic echocardiography (TTE) showed a round mass attached to the left atrial (LA) wall. Before anesthesia induction, TTE found that the mass has dropped from the LA wall, and was spinning in the LA causing intermittent obstruction of the valve. Anesthesia induction was then carried out under TTE monitoring, and transesophageal echocardiograph found another mass in the LA appendage after intubation. She underwent LA mass removal and mitral valve replacement, and was discharged uneventfully. Histopathology confirmed the diagnosis of thrombus. Our literature review identified 19 cases of ball thrombus between 2015 and 2024. The average age was 54.8 (range 3–88) years. Heart failure was present as the initial symptom in 11 cases, and most patients had mitral valve disease or concomitant with atrial fibrillation. 12 cases received surgery, and 7 received medical treatment only. 2 deaths occurred, one due to the obstruction of left ventricular inflow tract and the other due to the worsening of heart failure.

Conclusion

Ball thrombus is rare in clinical settings. Urgent thrombectomy should be performed as soon as possible, and echocardiography can be used for real-time monitoring during surgery.

Background

Ball thrombus is defined as an unattached clot with its cross-sectional diameter greater than the orifice of the heart chamber where it exists [1]. It is rare and may cause sudden death and embolism [2]. Once diagnosed, removing thrombus and eliminating etiology is regarded as gold standard [3]. We here present a woman with left atria (LA) ball thrombus, and was successfully managed through operation. Additionally, we performed a literature review to summarize the clinical features of this rare disease.

Case presentation

A 75-year-old woman presented to outpatient clinic because of palpitations and chest discomfort for 8 months. Her electrocardiogram showed atrial fibrillation. Transthoracic echocardiography (TTE) revealed rheumatic heart disease, moderate stenosis of mitral valve with minor regurgitation, minor to moderate regurgitation of tricuspid valve, LA dilated with a 3.6 * 5.1 cm mass attached to the left anterior wall, swaying with the cardiac cycle, and the echogenicity is slightly stronger (should be differentiated between large thrombus and myxoma), right atrial dilated, and minor pericardial effusion. She was posted for LA mass removal and mitral valve replacement.

Before anesthesia induction, the heart was inspected by the anesthesiologist with a TTE probe, and he found that the mass had dropped from the LA wall. The mass was spherical with a smooth surface, spinning in the LA causing the intermittent obstruction of the valve. Anesthesia induction was then carried out under TTE monitoring. Anesthesia induction was performed using 20 mg etomidate, 75 ug sufentanil, and 20 mg cisatracurium intravenously. During this period, there was a decrease in blood pressure, and phenylephrine 100 ug was intermittently administered while fluid replacement was accelerated. After reaching a certain depth of anesthesia, tracheal intubation was completed.

After induction, the heart was inspected by the anesthesiologist with transesophageal echocardiography (TEE) probe, which confirmed the TTE findings (Supplementary file S1). Moreover, TEE revealed another cone-shaped thrombus in the LA appendage, which was not detected by preoperative TTE (Fig. 1).

Fig. 1

TEE showed another thrombus in LAA, in addition to the one in left atrium

After adequate heparinization, cardiopulmonary bypass (CPB) was conducted. The intervention included removal of the clots, LA appendage occlusion, and mitral valve replacement (Fig. 2). Intraoperative exploration revealed thickening of the mitral valve leaflets and adhesions at the junction. Post CPB TEE showed good prosthetic valve function. She was detached from CPB with stable hemodynamics and her postoperative period was uneventful. Histopathological examination confirmed the mass as thrombus, and the removed mitral valve showed hyaline degeneration and mucinous degeneration.

Fig. 2

Ball-shaped mass and the mass from LAA. Histopathological examination confirmed them as thrombi

At the 1.5-month follow-up evaluation, there were no signs of relevant postoperative complications, and no new thrombus was identified on repeat echocardiographic examination.

Discussion and conclusions

Around 12% of patients with atrial fibrillation have LA thrombus [4]. Rarely, a ‘‘ball thrombus’’ is formed. This remodeling may be caused by sculpting effect of multiple collisions with LA wall and mitral valve apparatus and spinning of the thrombus [5].

for reviewing this uncommon disease, we searched PubMed for “ball thrombus” in recent decade [1,2,3,4,5,6,7,8,9,10,11,12,13,14,15,16,17,18,19]. In sum, 19 cases were identified. The clinical characteristics are shown in Table 1. There are 7 males and 12 females, with an average age of 54.8 years old. 3 cases have multiple thrombi. As for the initial symptom, 11 cases had heart failure and 4 cases had cerebral embolism. Twelve cases received surgical treatment, and 7 cases received anticoagulation therapy only. Two deaths occurred, one due to thrombosis blocking the left ventricular inflow tract and the other due to worsening heart failure.

Table 1 Literature review of ball thrombus

The thrombi should be differentiated from myxomas, since it alters the treatment strategies [19, 20]. The differences between myxoma and thrombus are sometimes confusing, although medical history and their characteristic appearance is generally helpful. Among the noninvasive imaging modalities, echocardiography is of primary importance. Cardiac myxomas typically appear as a mobile mass attached to the atrial septum by a narrow stalk, followed by the mobility and distensibility of the tumor [21]. Thrombi on the other hand, are generally immobile, by attaching to the LA wall by a broad base [22]. However, if they are pedunculated and mobile, like in our case, distinguishing between them may be difficult [14]. Final diagnosis relies on a pathology [15]. A medical history of MS and LA enlargement favor the diagnosis of thrombus, and anticoagulation and follow‑up can help to differentiate between them [23]. The thrombus may dissolve with anticoagulant therapy while no change will occur in myxoma.

The ball thrombus is considered to be a high risk of embolism [8]. However, no guideline exists to direct the treatment strategy [24]. Urgent thrombectomy possibly remains the best approach [1], with a survival rate of 90% [25]. Mitral valve replacement is indicated to treat valvular stenosis, along with ligation of the LA appendage [5]. Though there were few cases demonstrated disappearance of thrombus after anticoagulation therapy only [10], anticoagulation therapy should be considered as a treatment for free-floating ball thrombus only in extremely high-risk cases or for patients refusing surgery, due to the risk of superficial fragmentation and embolization [16]. Anticoagulation therapy is required after surgery [19]. In our case, the thrombus detached from the atrial wall before induction possibly due to the anticoagulation therapy before surgery.

The anesthetic management is challenging due to multiple risks such as embolization, obstruction of mitral valve, arrhythmias, and marked hemodynamic instability [23]. Echocardiography plays an important role in intracardiac thrombus detection, and TEE is the gold-standard technique to detect LA appendage thrombi [26]. In our case, the thrombus in LA appendage was not detected by TTE, but TEE discovered it after induction.

In conclusion, ball thrombus is rare in clinical settings. Urgent thrombectomy should be performed as soon as possible, and echocardiography can be used for real-time monitoring during surgery.