Disclosure. All the authors have no conflict of interest to disclose in this study.

Assessment of Left Atrial Deformation and

Dyssynchrony by Three-dimensional

Speckle Tracking Imaging: Comparative

Studies in Healthy Subjects and Patients

with Atrial Fibrillation

Atsushi Mochizuki, MD*; Satoshi Yuda, MD, PhD*

; Yukiko

Oi, MT

, Mina Kawamukai, MD*; Junichi Nishida, MD*;

Atsuko Muranaka, MD, PhD*; Hidemichi Kouzu*, MD, PhD;

Nobuaki Kokubu, MD, PhD*; Shinya Shimoshige, MD*;

Akiyoshi Hashimoto, MD, PhD*; Kazufumi Tsuchihashi, MD,

PhD*; Naoki Watanabe, MD, PhD

; Tetsuji Miura, MD, PhD*

Second Department of Internal Medicine*,

Department of Clinical Laboratory Medicine

,

Sapporo Medical University School of Medicine,

Sapporo, Japan

Division of Laboratory Diagnosis

,

Disclosure

All the authors have no conflict of interest

to disclose in this study.

Background 1

Left atrial (LA) strain which is measured

by strain rate imaging and

two-dimensional speckle tracking (2DS) is

impaired in patients with atrial fibrillation

(AF).

Inaba Y, et al. J Am Soc Echocardiogr 2005; 18: 729-36

Tsai WC, et al. Echocardiograpy 2009; 26: 1188-94

2DS is enable to quantify LA synchrony,

and LA asynchrony can predict AF

recurrence post electrical cardioversion.

A newly developed 3-dimensional (3D)

speckle tracking echocardiography (3DS)

can quantify 3D left ventricular (LV) strain

and LV dyssynchrony.

Saito K, et al. J Am Soc Echocardiogr 2009; 22: 1025-30

Tanaka H, et al. Am J Cardiol 2010; 105: 235-42

However, whether 3DS is applicable for

evaluation of LA functions remains

unclear. Furthermore, alterations in 3D LA

morphology and function in patients with

AF have not been characterized.

Objective

We examined whether LA strains

and synchrony are assessable by

3DS and how the 3DS parameters

are modified by AF.

Study Population

Healthy subjects: n=77

age 32

±

14 years, 48 males, 29 females

Patients with Non-valvular AF: n=30

・

Paroxysmal AF (PAF): n=20

age 61

±

6 years, 14 males, 6 females

・

Permanent AF: n=10

age 62

±

8 years, 8 males, 2 females

Control group and PAF patients were in sinus

rhythm at the time of echocardiographic

examination.

Exclusion criterion was presence of

regional or global LV systolic dysfunction

(ejection fraction [EF] <55%).

Conventional Echocardiographic Examination

Two-dimentional echocardiography 1. LA diameter (LAD, mm)

2. EF (%) (by biplane modified Simpson’s method) 3. LA volume index (LAVI, ml/m2_{): biplane Simpson’s}

method and normalized for body surface area 4. LV mass index (LVMI, g/m2₎

Pulsed-wave Doppler echocardiography Transmitral flow velocities

5. peak velocity during early diastole (E, cm/s) 6. peak velocity during late diastole (A, cm/s) 7. E/A

Tissue Doppler imaging

Myocardial velocities at the medial mitral annulus 8. peak velocity during early diastole (e’, cm/s) 9. peak velocity during late diastole (a’, cm/s) 10. E/e’

Artida (Toshiba Medical Systems, Tokyo, Japan) equipped with a PST-25SBT transducer was used in the present study.

Measurement of LA Strain by 2DS

The LA endocardial border was manually traced in both apical four- and two-chamber views and the software automatically tracks the contours on the subsequent frames.

Peak longitudinal LA strain during systole (2D-LSs) was calculated by averaging the value of the 6 segments.

[Representative measurements of 2D-LSs]

Measurement of LA Strain by 3DS

With 3D echocardiographic datasets, the software detects the LA endocardium using a semi-automated contour-tracing

algorithm and divides the LA into 16 segments.

LA longitudinal (LS), circumferential (CS) and area (AS) strains for each segment and maximal LA volume (3D-LAV) are

automatically calculated.

Peak LS, CS and AS are measured in systole (LSs, CSs, ASs)

and late diastole (LSa, CSa, ASa).

ASs 65%

ASa 25% Control

Assessments of LA Synchrony by 3DS

To quantify LA synchrony, standard deviations (SD) of times to peaks of regional LSs, CSs, ASs, LSa, CSa and ASa were calculated.

Each parameter of LA synchrony was corrected by the R-R’ interval.

[Representative 16 Segmental LA Area Strain Curves]

Control PAF

Feasibility and Time needed for

Analysis

2DS

3DS

p

value

Healthy subjects

77/76 (99%)

75/77 (97%)

NS

AF patients

30/30 (100%) 30/30 (100%)

NS

Time for analysis, min

4.0

±

2.3

3.3

±

1.9

<0.05

The feasibility of 3DS was comparable with

that of 2DS for LA longitudinal strain.

The mean time needed for analysis for 3DS

was 18%

shorter

than for 2DS (p<0.05).

Inter

observer Variability

mean 2D-LSs of observer 1 and 2 (%)

mean CSs of observer 1 and 2 (%) mean ASs of observer 1 and 2 (%) mean LSs of observer 1 and 2 (%)

CSs (CV=9.8%)

60

mean dif = -0.7 SD = 6.8

Intra

observer Variability

mean 2D-LSs of 1st & 2nd measurement (%)

CSs (CV=11.6%)

60

mean dif = -3.2 SD = 7.5

CV: Coefficient of Variation

mean LSs of 1st & 2nd measurement (%)

mean ASs of 1st & 2nd measurement (%) mean CSs of 1st & 2nd measurement (%)

Clinical Characteristics in

Age-matched

Healthy Controls and Patients with AF

Control

(

n=15

)

(n=20)

PAF

Permanent AF

(n=10)

Age, years

57.9

±

5.4

61.2

±

5.7

62.4

±

7.6

Male

12 (80%)

14 (70%)

8 (80%)

Systolic BP, mmHg

118

±

13

113

±

14

122

±

16

Diastolic BP, mmHg

79

±

9

74

±

8

79

±

16

Heart rate, beats/min

65

±

10

61

±

15

68

±

16

Hypertension

0

4 (20%) 5 (50%)

Diabetes mellitus

0

3 (15%)

5 (50%)

Calcium antagonist

0

8 (40%)

5 (50%)

ACE-inhibitors or ARBs

0

2 (10%)

3 (30%)

Beta-blockers

0

12 (60%)

2 (20%)

Duration of AF, years

-

7.4

±

6.7

11.6

±

8.2

Echocardiographic Parameters

Control

(

n=15

)

(n=20)

PAF

Permanent AF

(n=10)

2D-LAVI, ml/m

27

±

8

36

±

15*

51

±

15*

**

3D-LAVI, ml/m

26

±

7

35

±

14*

53

±

16*

**

LVMI, g/m

118

±

23

143

±

29*

137

±

35

LVEF, %

69

±

5

68

±

5

67

±

5

E, cm/s

60

±

12

68

±

1.7

88

±

18*

**

A, cm/s

62

±

11

61

±

24

-

DcT of E, ms

189

±

34

187

±

61

161

±

35

e’, cm/s

10.1

±

1.9

9.3

±

2.3

10.6

±

2.9

a’, cm/s

11.5

±

1.8

8.5

±

2.6*

-

E/e’

6.1

±

1.4

7.6

±

2.2

8.6

±

2.4*

Peak LA Strain during

Systole

- LA Reservoir Function -

2D-LSs

LSs

CSs

ASs

Age-matched Control

PAF

Permanent AF

* *,_** * *,_** * *,_** * *,_** (%)

*p<0.05 vs control, **p<0.05 vs PAF 0 10 20 30 40 50

LSa

CSa

ASa

Age-matched Control

PAF

*

*

*

Peak LA Strain during

Late Diastole

- LA Booster Pump Function -

*p<0.05 vs control

LA Synchrony during

Systole

- Synchrony in Reservoir Phase -

0 5 10 15 20 25 30

SD-LSs

SD-CSs

SD-ASs

Age-matched Control

PAF

Permanent AF

* * * * (%) * * (%)

0 10 20 30 40

SD-LSa

SD-CSa

SD-ASa

Age-matched Control

PAF

* _*

(%)

LA Synchrony during

Late Diastole

- Synchrony in Booster Phase -

*p<0.05 vs control

Control Permanent AF ASs 80% ASa 32% SD-ASs 3.5% SD-ASa 8.2% ASs 49% ASa 13% SD-ASs 4.6% SD-ASa 9.0% ASs 13% ASa N/A SD-ASs 11.2%

SD-ASa N/A PAF

Independent Predictors of

PAF Patients

- Multivariate Logistic Regression Analysis -

Model 1

Model 2

Odds

ratio 95% CI

p

value

Odds

ratio 95% CI

p

value

2D-LSs

0.71

0.045

CSs

0.77

0.043

ASs

0.90

0.011

SD of ASa

1.15

0.039

Model 1: age, LSs, LSa, CSs, CSa, 2D-LSs, lateral a’, 2D-LAVI, LVMI,

SD of LSs, SD of LSa, SD of CS, SD of CSa

Model 2: age, ASs, ASa, 2D-LSs, lateral a’, 2D-LAVI, LVMI, SD of ASs,

Sensitivity and Specificity of

Prediction of PAF

- ROC Analysis -

Optimal

Threshold

Sensitivity Specificity

AUC

2D-LSs

<26%

100%

75%

0.85

CSs

<32%

80%

95%

0.88

ASs

<57%

87%

85%

0.89

Summary 1

1. The feasibility of 3DS for assessing LA

function was comparable with that of 2DS for

assessing LA longitudinal strain.

2. Interobserver and intraobserver variabilities

of LA strains in 3DS were relatively small

compared with those of 2DS.

3. Not only longitudinal but also circumferential

and area strains of LA were reduced in both

PAF and permanent AF patients.

4. LA dyssynchrony during systole and late

diastole was significantly larger in patients

with AF than in age-matched controls.

5. 2D-LSs and CSs were significant predictors of

PAF patients in a model using directional LA

strain indices (model 1).

6. In a model using area strain indices (model 2),

ASs and SD of ASa were significant predictors

of PAF patients.

Clinical Implications

1. 3DS may be more suitable for serial and

comprehensive assessment of effects of

interventions (e.g. cardioversion and

pulmonary vein isolation) on LA functions and

also for risk stratification of patients with AF

and/or LV dysfunction.

2. Close examination of relationships between

changes in LA functions, including synchrony,

and development of PAF might provide novel

knowledge for prediction of new-onset AF.

Conclusion

3DS is feasible for measurement of both

LA strain and synchrony with excellent

reproducibility. 3DS shows significant LA

dysfunction and dyssynchrony in both PAF

and permanent AF patients. 3D LA strain

appears to be comparable to the 2D LA

strain for identifying PAF patients.