1. Radiofrequency Maze Operation for Permanent Atrial Fibrillation
高雄長庚醫院
心臟內科
陳勉成醫師
Mien-Cheng Chen, MD

2. Table of Contents Why to treat atrial fibrillation (AF)
Mechanisms of AF
Surgical treatment of AF

3. Background AF is the most common sustained cardiac arrhythmia
Unpleasant palpitation, aggravation of CHF and ischemic syndromes, sudden death (eg, WPW syndrome)
Compromised cardiac function: impaired LV function as a result of AF with rapid ventricular rate
Increase the risk of thromboembolism

4. Mechanisms of AF
Focal AF
Multiple wavelets hypothesis

5. Mechanisms of AF
The wavelength for circus defined as: the distance traveled by the depolarization wave during the period of the refractory period
wavelength = conduction velocity X
refractory period
Short wavelength of a premature beat, either by depressed conduction or shortened refractoriness, may lead to induction of AF

6. Atrial flutter
AFL was defined as a rapid atrial rhythm (rate > 240 beats/min) characterized by a constant beat-to-beat cycle length, polarity, morphology, and amplitude of the recorded bipolar electrograms and the presence of a constant, stable, and a single reentrant circuit)
Cir Res 1994;74:

7. Atrial fibrillation
AF was defined as a rapid atrial rhythm (rate > 260 beats/min) characterized by variability of the beat-to-beat cycle length, polarity, morphology, and/or amplitude of recorded bipolar atrial electrograms and the presence of an unstable reentrant circuit (ie, one changing in both location and cycle length), more than one reentrant circuit, and/or multiple activation fronts (wavelets)
Cir Res 1994;74:

9. Surgery for AF
1980, Cox et al. described the left atrial isolation procedure
1985, Guiraudon et al. described Corridor procedure
1987, Cox et al. introduced maze procedure
1994, Lin et al. described atrial compartment operation

10. Left Atrial Isolation
1980, Cox et al. performed the procedure in 10 dogs, all remained in normal sinus rhythm

11. Left Atrial Isolation
Graffigna et al. described the procedure in 100 patients with valvular heart disease
Operative mortality 3%
Early postoperative, 81.4% in sinus rhythm
3.1% late death
Long-term results with persistence of sinus rhythm in more than 60%
Ann Thorac Surg 1992;54:1093-8

13. Left Atrial Isolation
Electrically isolated the left atrium from the remainder of the heart
Loss of synchronous left atrial kick

15. Corridor Operation (Sinus Node-Atrioventricular Node isolation)
Electrically isolating the sinus node, a band of atrial tissue and AV node from the remaining atrial tissue

17. Corridor Operation
7/9 patients free of AF, 2 recurrent AF, permanent pacemaker in 4 patients for sinus node dysfunction
JACC 1991;17:970-5
32 patients lone AF, 68% free of any atrial arrhythmias at 4 years
Pace 1993;16:880

18. Corridor Operation
Compromise in hemodynamics secondary to the absence of synchronous atrioventricular contraction
Same physiological state as His bundle ablation
Vulnerability to systemic embolization

19. Atrial Compartment Operation
22 patients underwent mitral valve surgery
Immediately after operation 91% in sinus rhythm
68% maintained in sinus rhythm for > 1 week
64% maintained in sinus rhythm > 6 months
No surgical mortality complication
Left atrial paralysis: 11/15 at 1 week, 6/14 at 2 months
Right atrial paralysis: 9/15 at 1 week, 1/14 at 2 months

20. Maze Procedure 1987, Cox et al introduced the maze procedure
Cure AF (by separating and blocking all the potential macroreentrant pathways and narrowing the atrial tissue to block propagation of the microreentrant wavelets)
Restore AV synchrony
Preserved atrial transport function

21. Maze I

22. Maze II

25. Maze Procedure
46 patients, Doppler echocardiography, 8 ± 7 months after maze procedure
Right atrial (RA) contraction: 83%
Left atrial (LA) contraction: 61%
RA filling fraction: 32 ± 7% (control: 33 ± 8%)
LA filling fraction: 20 ± 5% (control: 36 ± 7%)
Decreased LA compliance
Cox et al. Circulation 1994;90[Part 2]: II 285-II 292

26. RF maze II and III operation
Between December 1995 and August 1996
12 patients with mitral valve disease and chronic AF (9M/3F; mean age 50 ± 14 yrs), underwent RF-maze II or III and concomitant valvular operation
10 patients in NYHA class III, 2 in class IV
Mean duration of documented AF: 31.3 ± 30.7 months (1-84 months)
Preoperative LA dimension 55.0 ± 6.3 mm (48-70)
MVD+AVD in 5 patients, MVD+TVD in 3, MVD+CAD in 1 and isolated MVD in 3

27. Characteristics of Patients
Case No.
Age/Sex
NYHA
AF duration
(months)
Heart disease
Procedures
Type of Maze 1
56/M 3
MSR, AR
MVR, AVR
III 2
32/M 48
MSR
MVP
47/F 72
MR, AR II 4
35/F 24
MSR, TR
MVR, TAP 5
63/M
MR, TR
MVP, TAP 6
54/F 36
MVR 7
34/M 8
38/M 9
44/M 12 10
57/M 18 11
76/M
MR, CAD
MVP, CABG
61/M 84
Ann Thorac Surg 1998;65:

30. RF maze II and III operation
2 surgical deaths (1 died of massive cerebral infarction 17th days after operation while in atrial rhythm; the other died of acute renal failure and refractory heart failure while in sinus rhythm)

31. RF maze II and III operation
Post-operative cardiac rhythm at 6 months:
6 patients in sinus rhythm, 2 in atrial rhythm, 1 in paroxysmal atrial tachycardia and 1 in AF

32. RF maze II and III operation
Doppler echocardiographic study at 6 months:
Right atrial contraction: 80%
Left atrial contraction: 30%

33. RF Maze II
RF Maze III

34. RF maze IV operation
Aim: to improve left atrial transport function

36. Efficacy of RF-Maze IV Procedure
Group 1: 13 patients with mitral valve disease and chronic AF underwent the RF-maze II (n=9) or III (n=4) procedure
Group 2: Between March 1997 and September 1999, 48 chronic AF patients with mitral valve disease received modified RF-maze IV procedure and concomitant valvular operation
Group 3: 58 chronic AF patients who had mitral valve disease underwent valvular operations only without maze procedure served as control

38. Mortality and Morbidity
Surgical death:
2 patients in Group 2 developed sick sinus syndrome and received VVIR pacemaker implantation
Group 1
Group 2
Group 3
2/13 (15.4%)
1/48 (2.1%),
4/58 (6.9%)

39. Restoration of Sinus Rhythm
Group 1: at a mean follow-up of 43 months,
sinus rhythm: 73% (8/11)
AF: 1 patient; paroxysmal AF: 1 patient
AFL: 1 patient
Group 2: at a mean follow-up of 16 months,
sinus rhythm: 87% (41/47)
AF: 3 patients
junctional rhythm: 1 patient
paroxysmal AT and sick sinus syndrome: 1 patient
Group 3: at a mean follow-up of 61 months,
sinus rhythm: 11% (6/54)
AF: 48 patients

41. Postoperative Doppler Echocardiographic Study
Group 1: at a mean follow-up of 43 months,
Transmitral A wave (+) in 55% (6/11)
Transtricuspid A wave (+) in 73% (8/11)
Group 2: at a mean follow-up of 16 months,
Transmitral A wave (+) in 74% (35/47)
Transtricuspid A wave (+) in 81% (38/47)
Group 3: at a mean follow-up of 61 months,
Transmitral A wave (+) in 11% (6/54)
Transtricuspid A wave (+) in 11% (6/54)

43. RF Maze II
RF Maze III
RF Maze IV

45. Atrial Size Reduction as a Predictor of the Success of RF-Maze Procedure
JCE 2001;12:

46. Atrial Size Reduction as a Predictor of the Success of RF-Maze Procedure
JCE 2001;12:

47. 陳勉成醫師, 張仁平醫師 高雄長庚醫院 心臟內科,心臟外科
Preoperative Left Atrial Size Predicts the Success of Radiofrequency Maze Procedure for Permanent Atrial Fibrillation in Patients Undergoing Concomitant Valvular Surgery
陳勉成醫師, 張仁平醫師
高雄長庚醫院
心臟內科,心臟外科

48. Aims
To test whether preoperative atrial size could determine the rhythm status after RF maze IV operation

49. Aims
To determine the best cutoff value of preoperative atrial size in predicting the sinus conversion by the RF maze IV procedure using linear discriminant analysis

50. Methods (Patient Population)
Between March 1997 and March 2002, 81 permanent AF patients with mitral valve disease received RF-maze IV procedure while undergoing valvular operation

51. Results
One surgical mortality (1.2%) due to pneumonia and sepsis; 1 died 13 months later as a result of acute necrotizing pancreatitis

52. Results
Two patients received transvenous VVIR permanent pacemaker due to sick sinus syndrome developed postoperatively

53. Results At a mean follow-up of 38 months in the remaining 77 patients
Sinus rhythm: 65 patients (84.4%)
AF in 9 patients; PAF in 2; persistent AFL in 1

54. Results Success (n=65) Failure (n=12) P value Age 51.7 48.9 NS
Sex (M/F)
32/33
6/6
Duration of AF (months)
36.2
62.1
LA pre (mm)
53.0
62.7
0.02
LAA pre (cm2)
45.0
67.5
0.03
RAA pre (cm2)
25.4
29.1
LVEDD pre (mm)
54.6
51.8
LVESD pre (mm)
35.6
34.9
EF pre (%)
61.6
60.2
RF time (mins)
59.2
68.9
LA RF time (mins)
35.5
43.4
0.01

55. Results
By multivariate stepwise logistic regression analysis, only preoperative LA area was significant independent predictor of sinus conversion (P < 0.005)

56. Results Preoperative LA area: cutoff value 56.25 cm2 Sensitivity: 50%
Specificity: 86.2%
Positive predictive value: 40%
Negative predictive value: 90.3%

57. Chen et al. Chest 2004;125:

58. Results Success (n=65) Failure (n=12) P value LA post (mm) 44.1 55.6
< 0.006
LAA post (cm2)
28.5
46.5
< 0.02
RAA post (cm2)
17.9
24.7
< 0.004
LVEDD post (mm)
48.0
51.0 NS
LVESD post (mm)
31.7
33.8
EF post (%)
62.3

59. Conclusions (I)
RF-maze IV procedure is effective in terms of restoration of sinus rhythm in permanent AF patients with mitral valve disease undergoing valvular operations

60. Conclusions (II)
Preoperative left atrial size could predict the postoperative rhythm status

61. Conclusions (III)
Patients who restore their sinus rhythm have significantly more atrial size reduction after operation than those who fail to restore their sinus rhythm

62. Predictor of Sinus Conversion by RF-Maze IV Procedure
Between March 1997 and March 2002, 81 chronic AF patients with mitral valve disease received RF-maze IV procedure while undergoing valvular operation
One surgical mortality (1.2%) due to pneumonia and sepsis; 1 died 13 months later as a result of acute necrotizing pancreatitis
Two patients received transvenous VVIR permanent pacemaker due to sick sinus syndrome developed postoperatively
At a mean follow-up of 38 months in the remaining 77 patients
Sinus rhythm: 65 patients (84.4%)
AF in 9 patients; PAF in 2; persistent AFL in 1
Chest 2004 in press

63. Predictor of Sinus Conversion by RF-Maze IV Procedure
Success (n=65)
Failure (n=12)
P value
Age
51.7 ±11.4
48.9 ±11.9 NS
Sex (M/F)
32/33
6/6
Duration of AF (months)
36.2 ± 44.6
62.1 ± 51.3
LA pre (mm)
53.0 ±8.2
62.7 ±12.2
0.02
LAA pre (cm2)
45.0 ±16.8
67.5 ±30.6
0.03
RAA pre (cm2)
25.4 ± 8.5
29.1 ± 11.2
LVEDD pre (mm)
54.6 ± 9.7
51.8 ± 7.9
LVESD pre (mm)
35.6 ± 9.3
34.9 ± 6.9
EF pre (%)
61.6 ± 13.3
60.2 ± 8.9
RF time (mins)
59.2 ± 13.0
68.9 ± 15.3
LA RF time (mins)
35.5 ± 9.6
43.4 ± 11.7
0.01
Hospital days
18.5 ± 17.2
16 ± 5.3
ICU days
6.4 ± 11.9
4.8 ±4.6

64. Predictor of Sinus Conversion by RF-Maze IV Procedure
By multivariate stepwise logistic regression analysis, only preoperative LA area was significant independent predictor of sinus conversion (P < 0.005)
Preoperative LA area < 56.2 cm2
Sensitivity: 86.2%
Specificity: 50%
Positive predictive value: 90.3%
Negative predictive value: 40%

65. Chest in press

66. Predictor of Sinus Conversion by RF-Maze IV Procedure
Success (n=65)
Failure (n=12)
P value
LA post (mm)
44.1 ± 7.6
55.6 ± 11.5
< 0.006
LAA post (cm2)
28.5 ± 9.8
46.5 ± 21.9
< 0.02
RAA post (cm2)
17.9 ± 3.9
24.7 ± 6.5
< 0.004
LVEDD post (mm)
48.0 ± 6.5
51.0 ± 5.7 NS
LVESD post (mm)
31.7 ± 6.7
33.8 ± 5.1
EF post (%)
62.3 ± 10.8
62.3 ± 5.2

67. Conclusion
RF-maze IV procedure is effective in terms of restoration of sinus rhythm in chronic AF patients with mitral valve disease undergoing valvular operations
Preoperative left atrial size could predict the postoperative rhythm status
Patients who restore their sinus rhythm have significantly more atrial size reduction after operation than those who fail to restore their sinus rhythm