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

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

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

Mechanisms of AF

Focal AF Multiple wavelets hypothesis

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

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;74:882-894

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;74:882-894

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

Left Atrial Isolation 1980, Cox et al. performed the procedure in 10

dogs, all remained in normal sinus rhythm

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

Left Atrial Isolation Electrically isolated the left atrium from

the remainder of the heart Loss of synchronous left atrial kick

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

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

Corridor Operation Compromise in hemodynamics

secondary to the absence of synchronous atrioventricular contraction

Same physiological state as His bundle ablation

Vulnerability to systemic embolization

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

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

Maze I

Maze II

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

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

Characteristics of PatientsCase No. Age/Sex NYHA AF

duration

(months)

Heart disease Procedures Type of Maze

1 56/M 3 1 MSR, AR MVR, AVR III

2 32/M 3 48 MSR MVP III

3 47/F 3 72 MR, AR MVR, AVR II

4 35/F 3 24 MSR, TR MVR, TAP II

5 63/M 4 72 MR, TR MVP, TAP II

6 54/F 3 36 MSR MVR II

7 34/M 3 2 MSR, AR MVR, AVR II

8 38/M 3 2 MSR, AR MVR, AVR II

9 44/M 3 12 MR, TR MVR, TAP III

10 57/M 3 18 MSR, AR MVR, AVR II

11 76/M 4 4 MR, CAD MVP, CABG

II

12 61/M 3 84 MSR MVP IIAnn Thorac Surg 1998;65:1666-72

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)

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

RF maze II and III operation Doppler echocardiographic study at 6

months:

Right atrial contraction: 80%

Left atrial contraction: 30%

RF Maze II

RF Maze III

RF maze IV operation

Aim: to improve left atrial transport function

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

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%)

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 patientAFL: 1 patient

Group 2: at a mean follow-up of 16 months,sinus rhythm: 87% (41/47)AF: 3 patientsjunctional rhythm: 1 patientparoxysmal AT and sick sinus syndrome: 1 patientAFL: 1 patient

Group 3: at a mean follow-up of 61 months,sinus rhythm: 11% (6/54)

AF: 48 patients

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)

RF Maze II

RF Maze III

RF Maze IV

Atrial Size Reduction as a Predictor of the Success of RF-Maze Procedure

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JCE 2001;12:867-874

Atrial Size Reduction as a Predictor of the Success of RF-Maze Procedure

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JCE 2001;12:867-874

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

Aims

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

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

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

Results One surgical mortality (1.2%) due to

pneumonia and sepsis; 1 died 13 months later as a result of acute necrotizing pancreatitis

Results Two patients received transvenous VVIR

permanent pacemaker due to sick sinus syndrome developed postoperatively

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

ResultsSuccess (n=65) Failure (n=12) P value

Age 51.7 48.9 NS

Sex (M/F) 32/33 6/6 NS

Duration of AF (months)

36.2 62.1 NS

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 NS

LVEDD pre (mm) 54.6 51.8 NS

LVESD pre (mm) 35.6 34.9 NS

EF pre (%) 61.6 60.2 NS

RF time (mins) 59.2 68.9 0.02

LA RF time (mins) 35.5 43.4 0.01

Results

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

Results Preoperative LA area: cutoff value 56.25

cm2

Sensitivity: 50%

Specificity: 86.2%

Positive predictive value: 40%

Negative predictive value: 90.3%

Follow-up Months

36 24 12 6 0

50

10

0 Inci

denc

e of

atr

ial

fibr

illa

tion

LA area < 56.25 cm2

LA area > 56.25 cm2

%

40

30

20

P < 0.003

Chen et al. Chest 2004;125:2129-2134

ResultsSuccess (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 NS

EF post (%) 62.3 62.3 NS

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

Conclusions (II) Preoperative left atrial size could predict

the postoperative rhythm status

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

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 patientsSinus rhythm: 65 patients (84.4%)AF in 9 patients; PAF in 2; persistent AFL in 1

Chest 2004 in press

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 NS

Duration of AF (months)

36.2 ± 44.6 62.1 ± 51.3 NS

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 NS

LVEDD pre (mm) 54.6 ± 9.7 51.8 ± 7.9 NS

LVESD pre (mm) 35.6 ± 9.3 34.9 ± 6.9 NS

EF pre (%) 61.6 ± 13.3 60.2 ± 8.9 NS

RF time (mins) 59.2 ± 13.0 68.9 ± 15.3 0.02

LA RF time (mins) 35.5 ± 9.6 43.4 ± 11.7 0.01

Hospital days 18.5 ± 17.2 16 ± 5.3 NS

ICU days 6.4 ± 11.9 4.8 ±4.6 NS

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%

Follow-up Months

36 24 12 6 0

50

10

0 Inci

denc

e of

atr

ial

fibr

illa

tion

LA area < 56.25 cm2

LA area > 56.25 cm2

%

40

30

20

P < 0.003

Chest 2004 in press

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 NS

EF post (%) 62.3 ± 10.8 62.3 ± 5.2 NS

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