Ventricular septal defect (VSD)

Congenital heart disease in adults	Congenital heart defects in children
Bileaflet aortic valve  Mitral valve prolapse  Patent foramen ovale (PFO) (20-30%)  Atrial septal defect (ASD) Ventricular septal defect (VSD) Patent ductus arteriosus (PDA) Coarctation of the aorta (CoA) Tetralogy of Fallot (ToF)	without shunt  - Acyanotic - aortic/pulmonary (sub)valvular disease, coarctation of aorta with left-to-right shunt  - Initially Acyanotic - ASD, VSD, PDA, anomalous venous return with right-to-left or right-to-bidirectional shunt - cyanotic - ASD/VSD with right heart outflow obstruction,    tetralogy of Fallot, Ebstein’s anomaly

 

* Congenital heart disease (CHD) is the most common congenital anomaly type.

* Prevalence : approximately 1 % of live birth.

* Embryogenesis (weeks 3 - 8) ; 심장은 발생 3주부터 시장하여 7주 말 또는 8주 초면 완성된다. 

* Most congenital heart defects are sporadic ; Unknown

대부분의 선천성 심장문제의 원인은 불분명하다.

단일 유전자 이상으로 인한 심장질환의 경우에는 Marfan syndrome, Noonan syndrome이 있다. 심장질환에서 염색체 이상은 약 13%의 환자에서 동반되지만 대부분은 유전과 환경의 상호작용에 의한 것으로 분류된다. 이 점을 충분히 설명할 것.

 

 

 

Disease can be divided into

1. Two categories of congenital heart disease : cyanotic and acyanotic.

 

청색증을 동반한 심질환 (Cyanotic)의 경우에는 청색증이 주 증상이며 RL shunt, TOF, Ebstein anomaly 등은 여기에 속한다. 비청색증 선천성 심질환(Acyanotic)의 경우에는 심부전이 주증상이고 LR shunt (ASD, VSD, AVSD, PDA)와 without shunt인 경우로 또 나뉜다. 

 

2. Two categories of shunt : Left-to-right shunt and Right-to-left shunt

 

선천적인 심장질환은 shunt를 동반한 질환, 동반하지 않은 질환으로 나눌 수 있다. 만약 동반하는 질환이라면 또 2가지, LR인지 아니면 RL인지로 나눌 수가 있다. LR shunt의 경우에는 산소화된 혈류가 다시 폐로 들어가는 경우로 중격이 결손된 ASD, VSD, 또는 PDA가 있다. LR shunt가 지속되면 폐고혈압으로 이어진다. 반면에 RL shunt의 경우에는 산소가 적은 정맥혈이 왼쪽 심장을 통하여 체순환을 하게 되기 때문에 청색증을 보인다. 

 

 

 

Prevalence rate 

VSD (most common) > ASD > PDA > TOF > PS > CoA > AVSD 

 

 

 

 

VENTRICULAR SEPTAL DEFECT (VSD)

 

VSD has defect in the septum that divides the right and left ventricles. It is most common congenital heart defect which associated with 

• Down syndrome
• Maternal diabetes
• fetal alcohol syndrome
• Intrauterine infections (e.g., TORCH)

 

 

It results in LR shunt.

Clinical features depend on

• size of defect which determines extent of shunting and age at presentation
• flow of arteries (Qp/Qs ; flow of pulmonary/flow of systemic)
• severity of pulmonary hypertension

 

Size of defect

Small defects (< 1cm²) are usually asymptomatic, however, typically louder murmur in small defects than large defects. Many VSDs spontaneously close in childhood (75-80% small VSDs) However, subaortic/subsrterial type dose not spontaneously close.

 

Medium and Large defects can lead to fetal condition as CHF, signs of hypertrophy of both ventricles. exertional dyspnea, exercise intolerance, pulmonary infections, growth retardation, dyspnea, syncope, chest pain, hemoptysis

Many VSDs spontaneously close in childhood (10-15% large VSDs). But severe case of large VSD can lead, if it untreated -> significant L-to-R shunt -> irreversible pulmonary vascular disease & Eisenmenger’s syndrome.

 

 

Eisenmenger’s syndrome mechanism summary 

Eisenmenger’s syndrome : Left to Right shunt → Prolonged pulmonary hypertension → Remodeling of pulmonary vessels → Irreversible pulmonary hypertension → Right ventricle hypertrophy → Reversal of blood flow → Cyanosis 

 

 

VSD types:

• membranous (70-80%) : pseudoaneurysum -> spontaneously close 
• muscular : less common in Asian
• other: AV canal, subaortic, subarterial / juxta-arterial ; more common in Asian; High risk of AR; It need surgical closure even thoug size of defect is small. 

 

 

Auscultation

• Harsh holosystolic murmur over the left lower sternal border. 
• Mid-diastolic murmur 

 

 

 

Treatment 

 

Many VSDs spontaneously close in childhood (75-80% small VSDs, 10-15% large VSDs)

Large defects with pulmonary hypertension need surgical operation.

 

Failure to correct VSD at the appropriate time can lead to anatomical changes in the pulmonary artery due to pulmonary hypertension, resulting in a high mortality rate immediately after surgery. In other words, if the appropriate timing is missed, it progresses to Eisenmenger's syndrome. In such a case, complications such as severe cyanosis, polycythemia, brain abscess, heart failure, etc., can lead to death in individuals in their 20s to 30s.

Therefore, Surgery for VSD is not feasible. In such cases, heart and lung transplantation or bilateral lung transplantation are the only viable alternatives.

대부분의 작은 결손의 경우에는 자연적으로 폐쇄된다. 그러나 동맥 주변의 결손의 경우에는 작더라도 수술을 하는 것이 옳다. 큰 결손의 경에는 시기를 놓칠 경우에 폐소동맥의 해부학적인 변화를 일으킬 수 있다. 즉, 적절한 시기를 놓친다면 Eisenmenger’s syndrome 로 진행하게 된다. 그렇게 되면 심각한 청색증, 객혈, 뇡농양, 심부전 등의 합병증으로 20-30대에 사망한다. 현재까지 유일한 대안은 심폐이식 또는 양측 폐 이식 수술 밖에 없다. (VSD는 만 1세 전에 수술하게 될 경우에 Eisenmenger 증후군으로 진행이 드물다. 시기를 놓치지 않도록 주의하자) 

 

Intermediate risk of endocarditis, prophylaxis Not recommended 
The clinical manifestations and diagnosis of infective endocarditis, and antibiotic prophylaxis to prevent endocarditis are discussed in detail separately.

- Dental procedures & some others, e.g. tonsillectomy, surgery involving infected skin/musculoskeletal tissue
- Unrepaired cyanotic CHD, including palliative shunts and conduits
- Completely repaired congenital heart defect with prosthetic material or device, whether placed by surgery or by catheter intervention, during the first 6 months after the procedure

- Repaired CHD with residual defects at the site or adjacent to the site of a prosthetic patch or prosthetic device (which inhibit endothelialization)

선청성 심장결손으로 인한 심내막염을 예방하기 위한 항생제의 사용은 즉각적인 사용은 권장되지 않으며 개별적인 논의가 필요하다.