第四章 討論
4.5 術後上心室頻脈之治療成效與手術短期預後
續性上心室頻脈的患者，未納入心房早期收縮（atrial premature contraction）或短 暫非持續性上心室頻脈（short-run or non-sustained SVT），故需要抗心律不整治 療比例較高 (Pfammatter et al., 2001; Rekawek et al., 2007; Valsangiacomo et al., 2002)。整體而言對心律不整治療的反應佳，經過適當治療心律不整通常很快便
能獲得控制，除了延長住院時間之外，無人因心律不整而死亡或出現嚴重心衰竭 等重大合併症，術後短期死亡率與術後無上心室頻脈的患者相當。過去其他研究 由於多將各類型的心率合併討論預後與死亡率，分析結果較為分歧 (Pfammatter et al., 2001; Rekawek et al., 2007; Valsangiacomo et al., 2002)，無法反應上心室頻脈 對術後短期死亡率的影響（表七）。
接受口服抗心律不整藥物治療的患者，六成經過平均六個月左右的口服藥物 治療後，便可逐漸停藥，停藥後僅一位復發。長期口服用藥治療時間的差異，可 能反應術後上心室頻脈多重因素的病生理機轉，若心律不整因手術前後血液動力 學、電解質的變化、手術過程的刺激或術後強心藥物等短期因素影響，或手術改 善了原本心臟的負荷，可能經過數個月的治療便可停藥；然而，如果心律不整發 生原因與疤痕組織、或因心臟持續存在壓力或容積負荷過大 (pressure or volume overload)，或先天結構異常，便可能需要長期用藥，或接受電燒、再次手術等治 療才能控制。術後發生上心室頻脈的患者，術後住院時間較長，對抗心律不整藥 物與非藥物治療反應良好，未增加術後短期死亡率或嚴重合併症發生率，手術短 期預後佳。
五、展望
手術疤痕組織在中長期上心室頻脈的病生理機轉佔有重要的相關性，心房頻脈好 發於多次手術或經過複雜心房重建手術的患者，這些患者對藥物治療有時不甚理 想，需要電燒或再度手術等治療；但在術後早期，特別是初次手術的病患，手術 疤痕組織的影響可能較有限，其他因素在此時期的影響相對更大，因此上心室頻 脈的好發族群、對治療的反應與預後等，與術後中長期心律不整不同。另一方面，
有三至四成的上心室頻脈患者，需要長期使用抗心律不整藥物維持性治療，無法 完全停藥，這些患者的心律不整可能不只涉及自身背景狀況與周術期因素，手術 的疤痕組織與未解決的容積或壓力負荷可能影響更大，臨床上需要調整治療策略 與方法，並評估心律不整對手術後中長期預後的影響。我們透過觀察性研究，配 合過去心律不整的病生理背景知識與流行病學分析所得的推論，尚需進一步實驗 性與基礎研究的證實，亦能對先天性心臟病患的手術後電生理變化有更深入探究。
六、Summary
6.1 Background
In patients with congenital heart disease (CHD), atrial arrhythmia mostly associated with underlying hemodynamic condition and cardiac surgery related factors. The lifelong prevalence of atrial arrhythmia in CHD patients was around 20%, usually increased with age. Certain cardiac structural anomalies may be associated with accessory atrioventricular conductions, and paroxysmal supraventricular tachycardia (PSVT) could be induced in postoperative stage. Late supraventricular arrhythmia in repaired congenital heart disease patients carries an unfavorable long-term outcome. It can cause heart failure or cardiogenic shock, depressed ventricular function, or stasis of atrial flow and thrombus formation. Therefore, the frequency of hospitalization and even mortality rate increase in those with associated supraventricular tachycardia.
However, the influence of supraventricular tachycardia in early postoperative stage was still unclear.
One small cohort study showed that the incidence of supraventricular tachycardia in postoperative stage was around 3.7%. The risk factors of postoperative arrhythmia were young age, low bodyweight, complicated surgical procedure, prolonged
cardiopulmonary bypass time and cross clamp time. Occurrence of arrhythmia in postoperative stage was related to prolonged ICU stay and ventilator use, also
increased mortality up to 9.3%. However, the characteristic of the study population of this early report was different from current surgical strategies. The finding of high perioperative mortality rate is not consistent with our clinical experience.
The pathophysiology of postoperative supraventricular tachycardia was a complex electromechanical problem. The mechanism is related to CHD structural associated conduction abnormality, postoperative pressure or volume overload, persistent residual lesions, surgical injuries to conduction system and myocardium, metabolic and electrolytes disturbance, and increased adrenergic tone in response to surgical stress or inotropic agent use.
6.2 Objectives
First, understand the incidence, natural history and risk factors of SVT in early post-op stage for CHD surgery. Second, analyze the outcome, treatment and its association with perioperative morbidity in CHD patients.
6.3 Hypotheses
There were 3 hypotheses of our study. First, postoperative SVT may be
associated with underlying CHD and previous operation. Second, postoperative SVT incidence may be increased by perioperative hemodynamic factors. Third, under
effective management, SVT may not increase postoperative morbidity and mortality.
6.4 Methods
We retrospectively reviewed the medical records of congenital heart disease patients who received congenital heart disease surgeries in NTUH during January 2010 to December 2015. The definition of early postoperative stage was the time of ICU stay after congenital heart disease surgery. The supraventricular tachycardia included atrial tachycardia, atrial flutter, atrial fibrillation, multifocal atrial
tachycardia and paroxysmal supraventricular tachycardia. The diagnosis of congenital heart disease could be grossly classified as acyanotic and cyanotic congenital heart disease. We sub-classified the cyanotic congenital diseases in to 5 categories:
tetralogy of Fallot, transposition of great arteries, heterotaxy syndrome, patients who received single ventricle repair surgeries, and other types of congenital heart diseases.
6.5 Results
There were 1404 patients with congenital heart disease received congenital heart disease surgeries in NTUH during 2010 to 2015. Their median age was 0.56 years old, 58.2% were male, and 2.4% had history of supraventricular tachycardia before this surgery. Cyanotic congenital heart disease accounted for 50.9% patients, and half of
them were tetralogy of Fallot. The patients received average 0.5 times of congenital heart disease surgeries before this surgery. Among them, 97.6% congenital heart disease surgeries were under cardiopulmonary bypass.
Totally 1650 surgeries were performed in these 1404 CHD patients; 32 patients who received 33 surgeries developed SVT in early postoperative stage. The incidence of early postoperative SVT is 2.3%. The age of patients with postoperative SVT ranged from 0 to 17.5 years old. 72% were younger than 3 years old. The most common type of SVT was atrial tachycardia 56%, followed by PSVT 28%. Mean atrial rate was 278 +/- 93.8 bpm, and mean ventricular rate was 197 +/- 40 bpm. The incidence of SVT in different CHD categories varied a lot. Heterotaxy syndrome had highest incidence (9.7%), followed by TGA (6.6%). The univariate and multivariate analysis showed that previous SVT history and complex cyanotic CHD, especially heterotaxy syndrome and TGA, were independent risk factors of early postoperative SVT. Other characteristic, including age, gender, previous surgery times, and bypass surgery this time, had no significant influence.
The perioperative hemodynamic condition of patients with postoperative SVT was relatively unstable. Half of them received emergent surgeries due to critical preoperative condition, and 6% needed ECMO support after surgery. Median length of ICU stay was 22 days. All SVT could be controlled by acute treatment: 22%
patients received adenosine, 68% used intravenous amiodarone, and 30% needed amiodarone for more than one day. Still 13% received DC cardioversion due to critical hemodynamic condition or limited response to medication treatment. The length of postoperative hospital stay of patients with SVT was significantly longer than that of patients without SVT (median 27 vs. 21 days). The perioperative
mortality was similar in patients with and without SVT (6.0 vs. 6.3%). All except one patients received maintenance oral antiarrhythmic agents, and 11 of them need 2 or more kinds of oral agents. Oral medication could be discontinued in 19 (59%) patients with only one recurrence. The median oral medication treatment duration was 137 days. Two patients, with diagnosis of RAI and other single ventricle, received ablation to control SVT.
6.6 Discussion
To our knowledge, the current study is the largest cohort study of early
postoperative SVT in CHD patients. The distribution of CHD categories was similar to the current trend of CHD surgery. The incidence of early postoperative SVT was low, but varied greatly with CHD categories. Overall incidence was 2.3%, and but up to 9.7% and 6.6% in heterotaxy syndrome and TGA. Univariate and multivariate analysis revealed that previous SVT history and complex cyanotic CHD, especially
heterotaxy syndrome and TGA, were independent risk factors of early postoperative SVT. The majority of heterodoxy syndrome in Taiwan was right atrial isomerism (RAI), which was commonly associated with conduction system abnormality, especially twin atrioventricular nodes. Due to the structural predisposition, SVT occurred more easily after cardiac surgeries. TGA often presented with hypoxia and shock soon after birth, and needed emergent surgery in the first few days of life. The mainstream of surgical procedure was arterial switch operative, which involved re-implantation of coronary arteries. The critical hemodynamic condition, young age and low body weight, and possibly hypoxic injuries of myocardium after coronary artery manipulation, might induce SVT in the early postoperative period. Previous SVT history was an independent risk factor of postoperative SVT, but seldom
mentioned in the past studies. Based on the possible pathophysiology of postoperative SVT, complex cyanotic CHD patients could possess multiple risk factors of recurrent SVT, including congenital structural abnormality, repetitive surgical interventions, residual pressure or volume overload, preoperative critical hemodynamics,
complicated surgical procedures and prolonged bypass time. Surgical manipulation, peri-operative hemodynamic change and postoperative inotropic agents use might induce the recurrence of SVT.
The response to anti-arrhythmic treatment and short-term surgical outcome were
generally good in patients with postoperative SVT. In our study, all except one patients needed long term oral anti-arrhythmic agents after acute management.
Among them, 60% could discontinue oral agents within 6 months. A few patients need radiofrequency ablation or long-term oral anti-arrhythmic medications control.
Comparing with those without SVT, patients with postoperative SVT were not related to increased surgical morbidity or mortality.
6.7 Conclusions
In conclusion, the incidence of early postoperative SVT was around 2.3%.
Patients with previous SVT history and complex cyanotic CHD were risk factors.
Postoperative SVT might increase length of hospital stay, but responded well to antiarrhythmic treatment, and did not pose increased risk of morbidity and mortality.
The short-term postoperative outcome was good. Most patients with postoperative SVT needed maintenance oral agents, and 60% could discontinue oral medication in 6 months.
七、參考文獻
Attenhofer Jost, C. H., Connolly, H. M., Dearani, J. A., Edwards, W. D., & Danielson, G. K. (2007). Ebstein's anomaly. Circulation, 115(2), 277-285.
doi:10.1161/circulationaha.106.619338
Avila, P., Mercier, L. A., Dore, A., Marcotte, F., Mongeon, F. P., Ibrahim, R., . . . Khairy, P. (2014). Adult congenital heart disease: a growing epidemic. Can J Cardiol, 30(12 Suppl), S410-419. doi:10.1016/j.cjca.2014.07.749
Birnbaum, S. E. (2002). Mechanisms of atrial reentry tachycardia after surgery for congenital heart disease. Progress in Pediatric Cardiology, 14(3), 205-209.
doi:https://doi.org/10.1016/S1058-9813(01)00139-4
Boehm, W., Emmel, M., & Sreeram, N. (2006). Balloon atrial septostomy: history and technique. Images Paediatr Cardiol, 8(1), 8-14.
Bouchardy, J., Therrien, J., Pilote, L., Ionescu-Ittu, R., Martucci, G., Bottega, N., &
Marelli, A. J. (2009). Atrial arrhythmias in adults with congenital heart disease.
Circulation, 120(17), 1679-1686. doi:10.1161/circulationaha.109.866319
Deal, B. J., Mavroudis, C., & Backer, C. L. (2007). Arrhythmia management in the Fontan patient. Pediatr Cardiol, 28(6), 448-456.
doi:10.1007/s00246-007-9005-2
Hoffman, T. M., Wernovsky, G., Wieand, T. S., Cohen, M. I., Jennings, A. C., Vetter,
V. L., Rhodes, L. A. (2002). The incidence of arrhythmias in a pediatric cardiac intensive care unit. Pediatr Cardiol, 23(6), 598-604.
doi:10.1007/s00246-001-0079-y
Khairy, P., & Balaji, S. (2009). Cardiac arrhythmias in congenital heart diseases.
Indian Pacing Electrophysiol J, 9(6), 299-317.
Ko, J. K., Deal, B. J., Strasburger, J. F., & Benson, D. W., Jr. (1992). Supraventricular tachycardia mechanisms and their age distribution in pediatric patients. Am J Cardiol, 69(12), 1028-1032.
Peretto, G., Durante, A., Limite, L. R., & Cianflone, D. (2014). Postoperative arrhythmias after cardiac surgery: incidence, risk factors, and therapeutic management. Cardiol Res Pract, 2014, 615987. doi:10.1155/2014/615987 Pfammatter, J. P., Bachmann, D. C., Wagner, B. P., Pavlovic, M., Berdat, P., Carrel, T.,
& Pfenninger, J. (2001). Early postoperative arrhythmias after open-heart procedures in children with congenital heart disease. Pediatr Crit Care Med, 2(3), 217-222.
Rekawek, J., Kansy, A., Miszczak-Knecht, M., Manowska, M., Bieganowska, K., Brzezinska-Paszke, M., . . . Kawalec, W. (2007). Risk factors for cardiac arrhythmias in children with congenital heart disease after surgical intervention in the early postoperative period. J Thorac Cardiovasc Surg,
133(4), 900-904. doi:10.1016/j.jtcvs.2006.12.011
Smith, A. H., Owen, J., Borgman, K. Y., Fish, F. A., & Kannankeril, P. J. (2011).
Relation of milrinone after surgery for congenital heart disease to significant postoperative tachyarrhythmias. Am J Cardiol, 108(11), 1620-1624.
doi:10.1016/j.amjcard.2011.07.023
Talwar, S., Patel, K., Juneja, R., Choudhary, S. K., & Airan, B. (2015). Early postoperative arrhythmias after pediatric cardiac surgery. Asian Cardiovasc Thorac Ann, 23(7), 795-801. doi:10.1177/0218492315585457
Valsangiacomo, E., Schmid, E. R., Schupbach, R. W., Schmidlin, D., Molinari, L., Waldvogel, K., & Bauersfeld, U. (2002). Early postoperative arrhythmias after cardiac operation in children. Ann Thorac Surg, 74(3), 792-796.
Walsh, E. P., & Cecchin, F. (2007). Arrhythmias in adult patients with congenital heart disease. Circulation, 115(4), 534-545. doi:10.1161/circulationaha.105.592410 Wu, M.-H., Wang, J.-K., Lin, J.-L., Lin, M.-T., Chiu, S.-N., & Chen, C.-A. (2008).
Long-term outcome of twin atrioventricular node and supraventricular tachycardia in patients with right isomerism of the atrial appendage. Heart Rhythm, 5(2), 224-229. doi:10.1016/j.hrthm.2007.10.010
Wu, M. H., Chen, H. C., Lu, C. W., Wang, J. K., Huang, S. C., & Huang, S. K. (2010).
Prevalence of congenital heart disease at live birth in Taiwan. J Pediatr, 156(5),
782-785. doi:10.1016/j.jpeds.2009.11.062
Wu, M. H., Wang, J. K., Lin, J. L., Lai, L. P., Lue, H. C., Young, M. L., & Hsieh, F. J.
(1998). Supraventricular tachycardia in patients with right atrial isomerism. J Am Coll Cardiol, 32(3), 773-779.
八、圖表
表一、病患特徵。研究族群手術年齡小，半數為發紺性心臟病，且複雜性心臟病 比例高，與現今先天性心臟病手術趨勢相符。
Demographics CHD patients, n=1404
(range or %)
Mean previous OP times Current OP with Bypass
0.5 (0 – 6) 1371 (97.6)
表二、術後早期有發生與未發生上心室頻脈之患者特徵比較。有上心室頻脈病史、 Median age (year) Male
SVT History
0.56 (0 – 48.2)
Ave. previous OP times Current OP with Bypass
0.45 (0–6) 1339 (97.6)
0.56 (0–3) 32 (100)
0.5–0.4
表三、危險因子單變項與多變項分析
Univariate Multivariate
Risk factor OR 95% CI OR 95% CI
Age 1.0 0.9–1.1
Male 1.6 0.8–3.5
SVT History 13.9 5.2–33.7 15.4 5.2–42.6 Previous CHD surgery
times
表四、上心室頻脈患者急性期病程特徵
Characterisitics Patient number (%) Perioperative course
Pre-op unstable Post-op ECMO
Median ICU stay days (range)
16 (50%) 2 (6%) 22 (3–263) Acute treatment
Adenosine
Amiodarone ≤ 1day > 1 days DC cardioversion
7 (22%)
(1372 patients, 1617 surgeries)
SVT
(32 patients, 33 surgeries)
p value
Median hospital stay of CHD surgery (days)
21 (1–953) 27 (9–278) 0.002
Perioperative mortality of CHD patients (%)
82 (6.0%) 2 (6.3%) 0.9
表六、上心室頻脈患者長期病程特徵
Characterisitics Patient number (%)
Long-term treatment Oral agents
≥ 2 agents Class III DC medication
Median medication use days (range) Catheter ablation
31 (97%)
Depressed ventricular function Mortality
* 診斷分別為兩側右心房症（right atrial isomerism）發生陣發性上心室頻脈，與 複雜發紺性心臟病接受單一心循環手術（situs inversus, atrioventricular discordance, double outlet right ventricle, pulmonary atresia）發生心房頻脈
表七、本研究與過去文獻對照
Rekawek (2007) Pfammatter (2001) Wu (2018) Study time Jan. 2005–Dec. 2005 Jul. 1996–Mar. 2000 Jan. 2010–Dec. 2015 Study patients
number
402 310 1404
Age Mean 29.5 months old SD +/- 46.8
2 days–15.4 years old
<1 y/o: 102 (32%)
Median 0.56(0–48.2) y/o
< 1 y/o: 60%
Acyanotic CHD Cyanotic CHD SV
Post-op ICU stay from post-op ICU admission to discharge
Post-op ICU stay
Monitoring methods
continuous EKG monitor
(1) continuous EKG monitor
(2) 12-lead EKG at pre-op and before discharge (3) 24hr Holter EKG
before discharge
(1) Continuous EKG monitor
(2) 12-lead EKG as needed
SVT incidence 3.7% (15 / 402) 2.9% (9 / 310) 2.3% (32 / 1404)
SVT type + PSVT AFL
Afib 1
(others not specified) 7 2
9
5 (AFL-Afib)
Risk factors (of post-op arrhythmia)
Lower age
Lower body weight
Higher surgical complexity
Longer bypass time
Longer cross-clamp time
(of post-op arrhythmia)
Infants
Cyanotic CHD
Prolonged bypass time
Higher post-op max troponin level
Hemodynamic significant residual findings
(of post-op SVT)
Cyanotic CHD
TGA
Heterotaxy
History of SVT
Surgical morbidity and mortality
Higher (9.26 vs. 2.6%) (with / without
arrhythmia)
No mortality related to SVT
Similar (6.3% vs. 6.0) (with / without SVT)
Use of long-term antiarrhythmic agents
Not mentioned 33% (3 / 9) 96.9% (31 / 32)
Treatment duration
Not mentioned < 3 months 60% discontinued within 6 months
* The number of patients received surgical procedures for acyanotic and cyanotic CHD
** Include heterotaxy and other single ventricle
*** Include TOF and pulmonary atresia
+ PSVT: paroxysmal supraventricular tachycardia, or atrioventricular reciprocating tachycardia; AFL: atrial flutter; Afib: atrial fibrillation
資料來源：(Avila et al., 2014)
圖一、先天性心臟病術後可能導致上心室頻脈之相關因子
先天性心臟病患術後上心室頻脈之病生理機轉，可能受到機械性與電生理多因子 共同影響。
Medications
Electrolytes disturbance
Electrolytes disturbance