ALCAPA

ALCAPA (Anomalous Left Coronary Artery arising from the Pulmonary Artery) also known as ALCAPA syndrome; Bland-White-Garland syndrome

This page is dedicated to Tania and other children/adults who have ALCAPA

Background

ALCAPA was first described in 1866 and the first clinical description in conjunction with autospy findings was described by Bland and colleagues in 1933 which is where the other name ‘Bland-White-Garland syndrome comes from.  Furthermore in 1962 it was reported in a series of 50 postmorten specimens carried out by Fontana and EdwALCAPAards that these postmortens demonstrated that most patients had died at a young age.

Anomalous left coronary artery from pulmonary artery (ALCAPA) occurrence is generally similar between males and females and is not considered an inheritable congenital cardiac defect but is a rare congenital cardiac malformation. It presents predominantly in infancy with:

features of myocardial ischaemia or cardiac failure, and
may be mistaken for common paediatric conditions such as:

  • colic,
  • reflux or
  • bronchiolitis.

However, the prognosis is good with early surgical correction, but awareness of this condition is essential for prompt diagnosis and referral to a tertiary cardiac centre.

What is Alcapa?

The acronym is ALCAPA which stands for Anomalous origin of the left coronary artery arising from the pulmonary artery which in laymans terms means a heart defect in the left coronary artery which is connected to the pulmonary artery instead of the aorta.  The left coronary artery carries blood to the heart muscle.

The ALCAPA occurs when the baby’s heart is developing, early in the pregnancy. The developing  blood vessels in the heart do not connect correctly.  In the normal heart, the left coronary artery starts in the aorta which is the major blood vessel that takes oxygen-rich blood from the heart to the rest of the body.  But when the left coronary artery starts in the pulmonary artery and it carries oxygen-poor blood to the left side of the heart. This is when the heart does not get enough oxygen and it begins to die which causes a condition leading to a heart attack in the baby.

This condition is known as “coronary steal” which further damages the heart in babies with ALCAPA.  Due to the low blood pressure in the pulmonary artery which causes the blood from the abnormal left coronary artery to flow toward the pulmonary artery instead of toward the heart. This then results in less blood and oxygen to the heart, which will also lead to a heart attack in a baby.  Coronary steal develops over time in babies with ALCAPA if the condition is not treated early.

Nowaday, the prognosis for patients with ALCAPA is dramatically improved due to a result of both early diagnosis using echocardiography with color flow mapping and improvements in surgical techniques, including myocardial preservation.

The ALCAPA anomaly may result from:

  1. abnormal septation of the conotruncus into the aorta and pulmonary artery, or from
  2. persistence of the pulmonary buds together with involution of the aortic buds that eventually form the coronary arteries.

ALCAPA is usually an isolated cardiac anomaly but, in rare incidences, it has been described with other congenital heart defects. These other congenital heart defects are:

  1. Patent Ductus Arteriosus,
  2. Ventricular Septal Defect (VSD),
  3. Tetralogy of Fallot (TOF), and
  4. Coarctation of the Aorta (CoA).

There are also extremely rare variations of anomalous origin of the coronary arteries from the main pulmonary artery which include the following:

  • The left anterior descending or circumflex branches
  • The right coronary, often discovered as an incidental finding on autopsy
  • Both the right and left coronary arteries, a circumstance not compatible with survival

What is the Pathophysiology of Alcapa?

ALCAPA does not present prenatally because of the favorable fetal physiology that includes

  1. equivalent pressures in the main pulmonary artery and aorta secondary to a nonrestrictive patent ductus arteriosus, and
  2. relatively equivalent oxygen concentrations due to parallel circulations.

ALCAPAThis results in normal myocardial perfusion and, therefore, no stimulus for collateral vessel formation between the right and left coronary artery systems is present. Shortly after birth, as the circulation becomes one in series, pulmonary artery pressure and resistance decrease, as does oxygen content of pulmonary blood flow. This results in the left ventricular myocardium being perfused by relatively desaturated blood under low pressure, leading to myocardial ischemia.

Initially, myocardial ischemia is transient, occurring during periods of increased myocardial demands, such as when the infant is feeding and crying. Further increases in myocardial oxygen consumption lead to infarction of the anterolateral left ventricular free wall. This often causes mitral valve papillary muscle dysfunction and variable degrees of mitral insufficiency.

Collateral circulation between the right and left coronary systems ensues. Left coronary artery flow reverses and enters the pulmonic trunk due to the low pulmonary vascular resistance (coronary steal phenomena). As a result, left ventricular myocardium remains underperfused. Consequently, the combination of left ventricular dysfunction and significant mitral valve insufficiency leads to congestive heart failure (CHF) symptoms (eg, tachypnea, poor feeding, irritability, diaphoresis) in the young infant. Inadequate myocardial perfusion likely causes significant chest pain and these symptoms of myocardial ischemia may be misinterpreted as routine infantile colic.

What are the signs and symptoms of ALCAPA?

The signs of ALCAPA include:

  • Abnormal heart rhythm
  • Enlarged heart
  • Heart murmur (rare)
  • Rapid pulse

The symptoms of ALCAPA include:

  • Crying or sweating during feeding
  • Pale skin
  • Poor feeding
  • Rapid breathing
  • Sweating
  • Symptoms of pain or distress in the baby (often mistaken for colic)

Symptoms can appear within the first 2 months of the baby’s life.

ALCAPA can be diagnosed in an infant. However, this defect may not be diagnosed until someone is a child or adult.

What are the Exams and Tests to Diagnosed ALCAPA?

The following exams and tests are carried out to diagnose ALCAPA.

  • Electrocardiogram – a test of the electrical activity in the heart.
  • Arteriography – a special dye injected into the blood vessels of the heart to see their structure and position.
  • Cardiac Catherisation – A thin tube (catheter) inserted in a blood vessel of the heart to measure blood pressure and oxygen levels.
  • MRI (Cardiac magnetic resonance imaging)
  • Chest x-rays
  • Echocardiogram – Ultrasound of the heart.

What is the Treatmeant for ALCAPA?

Treatment for ALCAPA is surgery which is needed to correct it.   Usually only one surgery is required which all depends on the baby’s condition and the size of the involved blood vessels.

If the mitral valve is seriously damaged from lack of oxygen, the baby may also need surgery to repair or replace the valve. The mitral valve regulates blood flow between the chambers on the left side of the heart.

If the baby’s heart is already severely damaged from lack of oxygen, a heart transplant may be an option.

Very ill babies may need treatment with medications before surgery. The medications help the baby get strong enough to have surgery.

Does my child need to take medications?
Your child may need to take the following medications:

  • Diurectics = “Water pills”
  • Inotropic Agents – medications that make the heart muscle pump harder.
  • Beta-blockers, ACE inhibitors – medications that lower the work load on the heart.

What is the Outlook (Prognosis)?

If the baby does not have treatment they most likely not survive their first year.  However, those who do survive without treatment are likely to have severe complications, or die suddenly during the following years.

Most babies do well with timely treatment and can expect a normal life. However, they will need routine follow-ups with cardiologist (a heart specialist).  If ALCAPA is left untreated, the mortality rate in the first year of life is 90% secondary to myocardial ischemia or infarction and mitral valve insufficiency leading to CHF. Sudden death may occur because of inadequate collateral circulation between the left and right coronary artery systems.

The surgical procedure of choice is direct transfer of the anomalous left coronary artery from the pulmonary artery (ALCAPA).  At most congenital heart surgery centres specialists have gained more experience with coronary artery transfer with the arterial switch operation, surgical repair of anomalous left coronary artery from the pulmonary artery which has benefited from refinement of these surgical techniques.  With the appropriate diagnosis, presurgical stabilization, and team-oriented postoperative care, patients with anomalous left coronary artery from the pulmonary artery are expected to have an excellent outcome.

Further refinement of long-term follow-up care with specialised stress and functional testing (eg, nuclear medicine perfusion, stress echocardiography) is anticipated.

Are they any Possible Complications?

Complications of ALCAPA include:

  • Heart attack
  • Heart failure
  • Heart rhythm problems
  • Permanent damage to the heart
  • Permanent damage to the mitral valve in the heart, requiring repair or replacement later in life

For Doctors/Nurses only.

  • If CHF is present, the infant appears distressed and exhibits tachypnea, tachycardia, diaphoresis, and irritability.
  • Auscultation may demonstrate a systolic murmur of mitral valve regurgitation and, possibly, a diastolic rumble of relative mitral stenosis best located at the apical left precordial region.
  • Rarely, a soft continuous murmur may be detected at the upper left sternal border that is reminiscent of a coronary artery fistula or a small patent ductus arteriosus.
  • The left ventricular precordial impulse may appear prominent and displaced both inferiorly and laterally.
  • The second heart sound may seem narrowly split with increased intensity of the pulmonic component, if left ventricular failure causes pulmonary artery hypertension secondary to elevated left atrial pressure.
  • In cases of severe CHF, hepatic enlargement may be observed, and the peripheral pulses may be diminished in intensity secondary to low cardiac output.

Disclaimer: The facts and opinions shown in this article are as accurate and up to date as possible, but are provided as general “information resources”, which may not be relevant to individual persons. This article is not a substitute for individual assessment and always take advice from a doctor who is familiar with the particular person.

Consult you or your child’s physician regard the specific outlook for you or your child.

Related Links and References

Other Congenital Heart and Vascular Malformations. In: Kliegman RM, Behrman RE, Jenson HB, et al., eds. Nelson Textbook of Pediatrics, 18th ed. Philadelphia, Pa: Saunders Elsevier;2007:chap 432.
Marelli AJ. In: Mandell GL, Bennett JE, Dolin R. Goldman: Cecil Medicine. 23rd ed. Philadelphia, Pa: Saunders Elsevier; 2007:chap 68.
Park MK. Park: Pediatric Cardiology for Practitioners, 5th ed. Philadelphia, PA: Mosby Elsevier; 2008.(1)
http://apps.uwhealth.org/health/hie/1/007323.htm
http://emedicine.medscape.com/article/905229-overview
www.netwellness.org/ency/article/007323.htm
(1)www.ingentaconnect.com/content/klu/431/2008/00000167/00000001/00000423?crawler=true
www.wrongdiagnosis.com/medical/alcapa_syndrome.htm
http://fortishospitalsblog.in/2010/05/rare-congenital-deformity-alcapa-anomalous-left-coronary-artery-from-the-pulmonary-artery-corrected-at-mulundfortis-hospitals/
www.invasivecardiology.com/articles/AVNRT-Unmasking-Asymptomatic-ALCAPA-Anomalous-Left-Coronary-Artery-Arising-Pulmonary-Artery
http://adam.about.com/encyclopedia/infectiousdiseases/Anomalous-left-coronary-artery.htm

Statistics

ALCAPA is a rare, congenital cardiac anomaly accounting for approximately 0.25-0.5% of all congenital heart disease. The incidence of ALCAPA does not vary geographically. ALCAPA is not considered an inheritable congenital cardiac defect. No risk factors for the occurrence of ALCAPA in any individual family are known, and ALCAPA is not associated with any syndromes or noncardiac conditions.

In this report we review the five cases that presented during our 5-year study period and discuss the incidence and clinical presentation of ALCAPA among infants. Our observed incidence of 1 in 4243 live births – 0.023 % – is higher than previously reported. ALCAPA may be more common than previously recognised, and there should be a high index of awareness among paediatricians, paediatric trainees and general practitioners to enable early surgical intervention and improved prognosis for these children. (1)

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