Total anomalous pulmonary venous return，TAPVR

review normal anatomy

http://www.sccs.swarthmore.edu/users/98/maryann/tapvr.html

Total Anomalous Pulmonary Venous Return or TAPVR is a congenital heart defect where the pulmonary veins do not connect to their normal point of attachment which is the left atrium of the heart. Instead the pulmonary veins connect to the right atrium or to other parts of the venous system.

TAPVR is not a problem during fetal development in utero because of high pulmonary vascular resistance and because the foramen ovale is open between the atria and shunts the circulating blood thus, bypassing the pulmonary system. At birth the pulmonary vascular resistance decreases and the foramen ovale may close causing blood flow to increase to the right heart and lungs. Cyanosis and congestive heart failure result.

If the TAPVR is not surgically corrected death within the first year of life is likely.

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a nice speculation on the formation of the TAPVR

Between Horizons XII and XVI of human embryo development the heart divides into four chambers and the common pulmonary vein, the lung bud and pulmonary circulation develop. The pulmonary veins mainly develop during Horizons XIII and XV which corresponds to Days 26 to 32 of human embryo growth. During Horizon XV the pulmonary veins are very close to the right and left horns of the sinus venosus. Thus, a small shift in position of the pulmonary veins during development can lead to the veins connecting to the right horn of the sinus venosus instead of the left horn. This may be the stage of development where TAPVR can arise. However, the mechanism of the development of the pulmonary veins is still controversial and so, this theory is speculative.

we are fearfully and wonderfully made. when i am studying medicine, it is not an infrequent thing to get be amazed by how He watches over us even when we were still in our mother's womb.

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TAPVR can be due to four possible anomalous connections of the pulmonary veins.

The normal figure illustrates the pulmunary veins attaching to the left atrium.
These four anomalies are:
1.Drainage into the Right Atrium
The pulmonary veins may attach to the right atrium if the atrial septum develops too far to the left.
2.Drainage into the Right Common Cardinal System
The pulmonary veins may connect to the right superior vena cava.
3.Drainage into the Left Common Cardinal System
The pulmonary veins may connect with the left superior vena cava.
4.Drainage into the Umbilicovitelline System
The pulmonary veins may connect to the portal vein or ductus venosus via a channel associated with the esophagus.

Most cases of TAPVR are not due to familial links. However, several familial cases have been reported and studied. The two predominant theories about the genetic mechanism of inheritance are that TAPVR is either multifactorially determined or is an autosomal dominant disease with incomplete penetrance and variable expressivity. Also a gene for familial TAPVR has been linked to chromosome 4p13-q12. Further studies are underway to further define the gene's chromosomal location.

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http://www.cincinnatichildrens.org/health/heart-encyclopedia/anomalies/tapvr.htm

Total Anomalous Pulmonary Venous Return (TAPVR) is a rare congenital malformation in which all four pulmonary veins do not connect normally to the left atrium. Instead all four pulmonary veins drain abnormally to the right atrium by way of an abnormal (anomalous) connection.

Total Anomalous Pulmonary Venous Return is classified into different types, based how and where the pulmonary veins drain to the heart:

A. Supracardiac Total Anomalous Pulmonary Venous Return -- The pulmonary veins drain to the right atrium via the superior vena cava. In this type of TAPVR, the pulmonary veins first come together behind the heart and then drain upwards to an abnormal “vertical vein.” This vertical vein joins the innominate vein which connects to the right superior vena cava and drains to the right atrium.

B. Cardiac Total Anomalous Pulmonary Venous Return -- The pulmonary veins come together behind the heart and then drain to the right atrium through the coronary sinus. The coronary sinus is the vein that normally returns blood from the heart muscle itself back to the right atrium after its oxygen has been depleted. The coronary sinus drains directly into the right atrium.

C. Infracardiac Total Anomalous Pulmonary Venous Return -- The pulmonary veins drain to the right atrium via the hepatic (liver) veins and inferior vena cava. In this type, the pulmonary veins join together behind the heart and then typically drain downwards, connecting to the liver's portal vein system. They then drain through the vascular bed of the liver and enter the right atrium from the hepatic veins.

All types of Total Anomalous Pulmonary Venous Return have to have an atrial septal defect (ASD). Because none of the pulmonary veins connect normally to the left side of the heart (and thus out to the body) blood is shunted from the right atrium across the atrial septal defect. Absence of an atrial septal defect in Total Anomalous Pulmonary Venous Return is not compatible with survival.

http://www.cincinnatichildrens.org/health/heart-encyclopedia/anomalies/graphicsummaries/totalgs.htm

9 下列何種總肺靜脈回流異常（total anomalous pulmonary venous return，TAPVR），最常合併肺靜脈回流阻塞？

總肺靜脈回流注入無名靜脈（innominate vein）

總肺靜脈回流注入上腔靜脈（superior vena cava）

總肺靜脈回流注入門脈靜脈（portal vein）

總肺靜脈回流注入冠狀靜脈竇（coronary sinus）

answer: portal vein

http://220.130.64.110/web/oldpage/tapvr.htm

無心臟雜音的先天性心臟病──

全肺靜脈迴流異常

一、前言：

　　 新生嬰兒在出生後，常因反覆性肺炎，又無心臟雜音，而被診斷為肺部感染。當發生嚴重發紺及心臟衰竭時，預後已趨惡化甚至快速夭折。全肺靜迴流異常雖屬罕見（約佔所有先天性心臟病的百分之二），但卻有嚴重症狀，如無治療病嬰在一歲內將有百分之80的死亡率，在新生兒期必需加以重視，觀察症狀，以早期診斷，早期治療。

二、定義及分類：

　 全肺靜脈迴流異常（Total Anomalous Pulmonary Venous Connection/Return---TAPVC 或 TAPVR）是指所有肺靜脈都不直接回到左心房，而採直接或借由體靜脈間接回到右心房。依據異位連接部位做解剖分型，Darling等分為四型：

第一型：心臟上型，約佔50%，連於左側無名靜脈，上腔靜脈或奇靜脈。約有70%連於左側無名靜脈。

第二型：心臟型，約佔30%，連於右心房，或經冠狀靜脈竇再入右心房。

第三型：心臟下型或膈下型，約佔13%，連於門靜脈、下腔靜脈、靜脈導管或肝靜脈。

第四型（混合型）：至少同時存在上述兩型以上，約占7%。

三、病灶特性

1. 連接至左側無名靜脈（心臟上型）為最常見的全肺靜脈迴流異常，肺靜脈在左心房後面匯合成一腔室，再由其左側接一管道稱垂直靜脈，在左側肺門前面向上進入上縱隔腔，在主動脈弓之前，向上開口入左側無名靜脈，經上腔靜脈回到右心房。當垂直靜脈上行時，位在左側肺動脈和左側支氧管之間，出生後，因肺動脈血流增多，愈益擴張而壓迫垂直靜脈，使肺靜脈回到右心房途中受阻，稱為血流動力學的夾卡。

2. 連接到上腔靜脈時，全肺靜脈匯合腔經右側的管道走右側肺門之前，向上開口入上腔靜脈的後壁。有的也可開口入奇靜脈。

3. 連到右心房時，全肺靜脈匯合後開口入右心房的後下部或肺靜脈各自分別開口進入右心房。開口部的梗阻，則較少見，但常伴有其他畸型。

4. 連接冠狀靜脈竇：如同冠狀竇型心房間隔缺損，造成冠狀靜脈竇擴張，但竇道與左心房間並無左心房壁缺損。

5. 連到膈下靜脈時，全肺靜脈匯合腔經由一根下降垂直靜脈，經食道前面，向下穿過膈肌的食管裂孔入腹部，與肝門靜脈，靜脈導管，肝靜脈或下腔靜脈連接。肺靜脈因回到右心房路途遙遠，且穿過膈裂，將受到外來壓迫及迴流遲滯，使肺靜脈回流受到阻塞，血流積存肺內產生嚴重肺水腫，導致出生數日後夭折。

6. 肺靜脈回流異常，常發生阻塞部位有：

　　ａ．垂直靜脈進入左側無名靜脈或夾在左側肺動脈及左側支氣管之間，約：40%-50%。

　　ｂ．上腔靜脈：肺靜脈匯入上腔靜脈開口處，約70%。

　　ｃ．冠狀靜脈竇：匯入竇腔的開口或竇道入右心房的開口，約：10%。

　　ｄ．右心房：肺靜脈入右心房的開口，約5%。

ｅ．隔下靜脈：肺靜脈回流受膈肌壓迫，或入門靜脈開口處，可視為必然會發生阻塞。

7. 伴發畸型：

　 約有¹/₃ 的病例併發有其他心血管畸型，如：單一心室，總動脈幹，完全性大動脈轉位症，肺動脈閉鎖，無脾綜合症等。其中，約有¹/₄病人合併有心房異構體（附件１）。

四、病態生理：

　 體靜脈及肺靜脈，回心血都在右心房會合。肺循環血流經右心室到肺動脈，造成肺動脈血含氧增高，血流量大，肺動脈擴張。體循環的血源則端賴心房間隔的通道，如心房間隔缺損太小或僅為一未閉合的卵圓孔，則血流入左心房有限，將造成體循環血流量不足。肺循環的阻力端賴肺靜脈回右心房的路途有無阻塞而定，依阻塞嚴重度，可分為三個類型：

１．肺靜脈嚴重阻塞：肺動脈壓力高，肺循環嚴重充血，造成肺部通過量減少（PBF↓）。

２．肺靜脈中度阻塞：肺動脈壓力高，但肺血流量增多（PBF↑）。

３．肺靜脈無阻塞：肺動脈壓力不高，但肺血流量增多（PBF↑）。

　 當全肺靜脈回流無阻塞，出生時，因肺循環阻力高，所以體循環與肺循環血流量大致相等。出生後，肺部高壓逐漸下降，將使肺循環量遽增。但肺動脈壓往往增高不多，患兒存活較長。全肺靜脈回流異常如合併阻塞，常使肺靜脈瘀滯，造成肺微血管床壓力升高，導致肺水腫，肺動脈高壓造成右心衰竭。

五、臨床表現：

臨床症狀端視（一）肺靜脈回流阻塞程度及肺高壓（二）心房間隔通道所控制的體循環血流量來決定發紺及心臟衰竭的嚴重度。

◎無阻塞者：因肺血流量增加造成心臟衰竭，患兒常以呼吸急促，餵食因難，體重不增及常有反覆性呼吸道感染為表現。但青紫並不明顯，患兒約有80%死於一歲內，大多在三個月內死亡。如單純的心房中隔缺損一般。理學檢查可完全無心雜音，肺動脈瓣區可呈第二度收縮期雜音，可存在第二心音固定分裂（Ｓ2 Splitting），心電圖呈心軸右偏，右心室肥厚，右心房增大。心臟超音波可見右心房右心室擴大，心尖四腔室無法見到肺靜脈回流，胸骨旁短軸切面或劍突下切面可見肺靜脈匯合腔及垂直靜脈，而精確診斷。胸部Ｘ光可見肺野血流增加，右側房室增大，肺動脈幹突出，心上型全肺靜脈回流異常到左側無名靜脈者可見心臟影像呈“８”字型或雪人樣。心導管可定位異常的肺靜脈迴流，探知阻塞的嚴重度，並可測量心房間隔管道大小。如果右側心房壓力高於左心房壓力達２毫米汞柱以上，表示心房間隔管道過小。可同時進行Rashkind心房間隔造口術，以維持左心室血流量，。

◎阻塞者：全部肺靜脈回流異常，如途中遇到阻塞，將造成肺靜脈積血，肺水腫。患兒在出生後不久會呈現發紺及呼吸急促，餵食困難，心臟衰竭。常於數日或延至３、４個月內死亡，易誤診為肺炎。如屬異位連接到膈肌下靜脈，舌嚥、哭鬧、使勁排便等動作，將提高腹腔內壓力或使膈肌的收縮而加重對肺靜脈垂直降支的阻塞，從而加重發紺及呼吸困難，甚至導致缺氧發作。理學檢查呈症狀嚴重，但心臟表徵卻很少，可全無心雜音，肺底部可有濕囉音；肝臟腫大。心電圖呈右心室肥厚，右心房可不大，因肺靜脈回心血減少。胸部ｘ光呈Kerley B線，肺野上部靜脈影增粗，可被誤解為肺部疾病。心導管可診斷異常連接所在位置，當右心房壓力不高但肺動脈楔壓很高時，即要懷疑此病。

六、治療：

　 以心導管進行Rashkind心房造口術擴大心房間隔管道以增加體循環血流量，並減少肺循環血流量而減輕肺水腫，使病嬰可暫時存活而等待手術治療。因左側心房及心室偏小，手術前常有肺水腫，肺循環阻力又高均為不利因素，使手術危險性偏高。自1991年以後，手術死亡率已大幅下降至13.6%以下，然而年齡在30天內手術死亡率還是偏高。而膈膜下型的全肺靜脈回流異常手術死亡率也高於其它類型，手術方法的選擇上也以經心房手術方法有較高的存活率。根據統計，手術時如年齡低於30天，手術前已開始使用體外循環膜性氧合器（ECMO），採用心臟後面修補法等，則將有顯著的死亡率。

七、總結：

　 當我們面臨此一罕見，卻具有高死亡率，症狀不明顯又無顯著心雜音的警訊，而常誤為吸呼道感染的全肺靜脈回流異常，應對的方法，應時時將它列入發紺及心臟衰竭病嬰的憶斷，以期早期診斷，並立即安排手術治療，以提高存活率及減少併發症。