ORIGINAL ARTICLE Year : 2022  |  Volume : 32  |  Issue : 3  |  Page : 145-147

Evaluation of left atrium/left atrial appendage function in cases with systemic embolization in the setting of normal transthoracic echocardiography and normal sinus rhythm

Niloufar Samiei, Abdolali Ehsani, Behshid Ghadrdoost, Mohaddeseh Behjati
Heart Valve Disease Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Echocardiography Research Center, Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran, Iran

Date of Submission28-Jan-2022Date of Decision02-Jun-2022Date of Acceptance12-Jul-2022Date of Web Publication16-Nov-2022

Correspondence Address:
Mohaddeseh Behjati
Rajaie Cardiovascular Medical and Research Center, Iran University of Medical Sciences, Tehran
Iran

Source of Support: None, Conflict of Interest: None

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DOI: 10.4103/jcecho.jcecho_4_22

Background: Various left atrium (LA) and left atrial appendage (LAA) anatomies and functions could be associated with embolic events. Aims and Objectives: We aimed to investigate the impact of variation in LAA and LA functions on the occurrence of systemic embolization in normal sinus rhythm and normal echocardiography findings. Materials and Methods: This cross-sectional study was performed on 22 patients with documented peripheral emboli versus 32 control subjects. Results: LA area, LAA area, ejection fraction (EF) of LA/LAA, LAA velocity and tissue Doppler imaging (TDI) of LA walls, left ventricular diastolic function, and EF were determined. There were statistically significant differences between LAA area, LAA EF, TDI of lateral LA wall, and TDI of anterior LA wall in cases versus controls. Conclusion: Echocardiography findings in LAA and LA functions could help to identify high-risk patients for embolic events in normal sinus rhythm cases.

Keywords: Echocardiography, embolization, left atrial appendage

How to cite this article:
Samiei N, Ehsani A, Ghadrdoost B, Behjati M. Evaluation of left atrium/left atrial appendage function in cases with systemic embolization in the setting of normal transthoracic echocardiography and normal sinus rhythm. J Cardiovasc Echography 2022;32:145-7
How to cite this URL:
Samiei N, Ehsani A, Ghadrdoost B, Behjati M. Evaluation of left atrium/left atrial appendage function in cases with systemic embolization in the setting of normal transthoracic echocardiography and normal sinus rhythm. J Cardiovasc Echography [serial online] 2022 [cited 2022 Nov 17];32:145-7. Available from: https://www.jcecho.org/text.asp?2022/32/3/145/361273   Introduction 

In many patients with an embolic event, no source for embolism has been identified.[1] Association between atrial cardiopathy and atrial dysfunction with embolic stroke has been reported previously.[2],[3],[4] Decreased compliance of left atrial (LA) walls depicted by tissue Doppler imaging (TDI) has been seen in situations without sinus rhythm (normal sinus rhythm [NSR]).[5] Although left atrial appendage (LAA) has been largely considered a nonfunctional organ, its unique function is changed in various disease states such as atrial fibrillation (AF) and could be a prime site for thrombus formation. This could explain the role of LAA dysfunction in stroke pathogenesis.[6],[7] Various parameters of LA and LAA dysfunctions have been evaluated in the presence of AF rhythm. There are few studies regarding the role of LA and LAA dysfunctions in patients with NSR and systemic embolization. Thus, the purpose of this study was to investigate the variation of LAA and LA functions with systemic embolization in patients with NSR and normal thoracic echocardiography (TTE) findings.

  Methods 

In this cross-sectional study, 22 patients with documented peripheral emboli versus 32 control subjects were evaluated. The inclusion criteria were the absence of any source of emboli which means negative carotid Doppler ultrasonography and the absence of any mass on valves or cardiac chambers found in TTE. TTE and transesophageal echocardiography were performed by a cardiologist and echocardiologist, respectively, who were blind about the status of participants regarding embolic status. The applied echocardiography machine was Philips Echo Machine EPIQ 7, VA, USA. In all participants, LA area, LAA area, ejection fraction (EF) of LA/LAA, LAA velocity and TDI of LA walls, left ventricular (LV) diastolic function, and LVEF were determined. LA and LAA functions were calculated using measurement of fractional area change (FAC). Data were expressed as mean ± standard deviation and analyzed through an independent samples t-test using SPSS v. 18 (SPSS inc., Chicago, IL, USA).

  Results 

In this study, patients with embolic events were significantly older than the control group (55.04 ± 13.86 vs. 39.93 ± 21.95, P = 0.006). There were statistically significant differences between LAA area (4.09 ± 0.58 vs. 2.88 ± 0.82, P < 0.001), LAA EF (78.69 ± 7.15 vs. 73.91 ± 8.77, P = 0.04), LVEF (54.31 ± 3.19 vs. 56.40 ± 5.71, P = 0.003), TDI of lateral LA wall (11.64 ± 3.58 vs. 13.69 ± 3.66, P = 0.04), and TDI of anterior LA wall (10.41 ± 2.89 vs. 12.59 ± 3.64, P = 0.01) between case and control groups, respectively. Other parameters showed no significant difference between the case and control groups. Data are depicted in [Table 1].

Table 1: Comparison of echocardiographic parameters between patients with embolic events and controls

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One of the LAA tissue Doppler images obtained by the Philips Echo Machine EPIQ 7 is shown in [Figure 1].

Figure 1: Tissue Doppler image of LAA that is obtained by Philips Echo Machine EPIQ 7. LAA: Left atrial appendage

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  Discussion 

Our data demonstrate that lower TDI measures of anterior and lateral LA walls could predict the development of systemic embolization events in NSR cases. Donal et al. have demonstrated that contrast-enhanced TDI index of LAA could provide quantitative data regarding the prothrombotic state of the LAA cavity in AF cases.[8] Kang et al. have found no differences in strain rate among LA walls in cases with paroxysmal AF (PAF) during NSR, regardless of stroke state,[9] but our data support lower TDI of anterior and lateral LA walls which could be a marker of at-risk patients for embolism.

Various LAA functional parameters have been attributed to enhanced risk of stroke in the presence of AF rhythms such as spontaneous echo contrast and nonchicken LAA morphology, but available data are rare in NSR status.[10],[11] We have tried out to seek a more comprehensive assessment of LAA function. We have measured LAA function using the measurement of LAA FAC. Shimizu et al. showed lower LAAEF and larger LAA area in the acute stroke phase in cases with NSR which was attributed to the presence of PAF.[12] Our data are on the same side with their findings, but still, data are limited in NSR cases. We have found lower LAAEF in association with systemic embolism in NSR, but we could not rule out the occurrence of PAF in our NSR participants. Thus, PAF is still an explanation for lower LAAEF in our NSR participants.

We also observed an increased risk of embolism in the setting of NSR in elder subjects and in cases with reduced LVEF. Reduced LVEF and advanced age, per se, are potential risk factors for the development of embolism.[13],[14],[15] Finally, a package of echocardiographic-derived parameters such as LAA area, LAAEF, and TDI of lateral and anterior LA walls could be used for the identification of high-risk patients for the development of embolic events in the NSR state.

  Conclusion 

Reduced LA and LAA functions determined by LAA area, LAAEF, and TDI of lateral and anterior LA walls could indirectly identify patients at risk for development of embolic events in the setting of NSR. These parameters could be used for the assessment of LA and LAA functions in NSR cases but need further investigation.

Ethical statement

The study was approved by the institutional Ethics Committee of Iran University of Medical Sciences by Approval No: RHC.HC.IR.REC.1394.46.

Financial support and sponsorship

Nil.

Conflicts of interest

There are no conflicts of interest.

 

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  [Figure 1]
 
 
  [Table 1]