ALCAPA – Anomalous Left Coronary Artery from the Pulmonary Artery

ALCAPA - Anomalous Left Coronary Artery from the Pulmonary ArteryEmbryology is amazing. Seriously. Think about it. Growing from one cell to all of the complex structures that form our organs is literally miraculous. It is shocking that it is able to occur correctly at all and it should be no surprise when it doesn’t go perfectly. Unfortunately, when it doesn’t go perfectly, terrible outcomes can become evident. We have previously discussed some issues when chromosomes don’t migrate properly (ex, Down’s Syndrome). We have also looked at what can happen when arteries form incorrectly (ex, AVM). Now let us take a moment to ponder the issues that can arise when an artery finds its origins incorrectly in an adjacent structure – Anomalous Left Coronary Artery from the Pulmonary Artery (ALCAPA).

 

ALCAPA: Basics

  • Anomalous Left Coronary Artery from the Pulmonary Artery is a life-threatening congenital abnormality.
    • The coronary artery, instead of originating from the aorta, arises from the pulmonary artery.
      • Early on, when pulmonary vascular pressures are high, there is flow from the pulmonary artery to the myocardium.
      • Later, when pulmonary vascular resistance decreases, blood is “stolen” from the myocardium and flows retrograde to the pulmonary artery.
      • Collateral blood vessels can help compensate for diminished myocardial perfusion.
        • Even with collateral perfusion, myocardial damage still occurs.
        • LV scarring and diminished LV function
    • Leads to:
      • Myocardial ischemia
      • Left ventricular dysfunction
      • Mitral insufficiency
      • Congestive heart failure
      • Arrhythmias
      • Sudden Death
  • It is a rare disease (estimates of 1 in 300,000 live births; <0.5% of congenital heart disease cases)
  • Usually manifests as an isolated defect, but can be associated with other defects in ~5% of cases.

 

ALCAPA: Presentation

  • Often asymptomatic at birth. [Levitas, 2016]
  • Two primary clinical variants: [Gonzalez, 2015]
    • Infants (< 2 years of age)
      • Most common type (>75%)
      • Poor collateral circulation
      • Symptoms begin around 2 months of age, coinciding with reduction in pulmonary vascular resistance -> coronary steal -> ischemia
      • Present with signs of CHF or Dilated Cardiomyopathy
        • Irritability
        • Poor feeding
        • Grunting
        • Sweating
        • Recurrent wheezing – “Bronchiolitis”, “Asthma” [Levitas, 2016]
        • Failure to Thrive [Levitas, 2016]
        • Poor perfusion
        • Cardiogenic shock
      • ECG with evidence of ischemia
        • Often anterolateral leads
        • Q waves in lateral limb leads should catch your attention!
    • Older Children (> 2 years of age)
      • Have more substantial collateral vessels
        • Clinical pictures can vary based on degree of collateral blood supply. [Levitas, 2016]
      • Often are asymptomatic until late childhood or even early adulthood
      • At risk for SUDDEN DEATH!
      • Present with:
        • Murmur (MR)
          • May be only finding
          • Due to ischemia of the papillary muscles
          • Lack of MR diminishes likelihood of ALCAPA. [Gonzalez, 2015]
        • Angina
        • Signs of CHF from borderline heart function worsened by acute (viral) illness
          • May be initially diagnosed as myocarditis. [Levitas, 2016]
        • Sudden Death (that is a terrible presenting complaint).
      • ECG may be normal (that’s scary).

 

ALCAP: Evaluation

  • ECG – looking for ischemia
  • CXR – looking for cardiomegaly
  • Troponin – if concern for ischemia on ECG
  •  Imaging:
    • Transthoracic Echo is the primary screening tool, but has it’s limitations. [Arunamata, 2015]
      • Even in the setting of a normal echo, evidence of ischemia on ECG and dilated cardiomyopathy with mitral regurgitation suggests ALCAPA. [Gonzalez, 2015]
    • Cardiac CT and MRI can be useful in depicting the complex anatomy and assist with planning of surgery. [Duan, 2015, Arunamata, 2015]
  • Unlike other cardiomyopathies in children, the ischemic cardiomyopathy due to ALCAPA can respond to surgical therapy. [Gonzalez, 2015]
  • When detected early and repaired surgically, outcomes are excellent and re-intervention is rare. [Cabrera, 2015; Gonzalez, 2015]

 

Moral of the Morsel

  • ALCAPA is rare, but potentially devastating (like so many other pediatric illnesses). Be vigilant!
  • Get the ECG for the critically ill infant and look for ischemia!
  • Be wary of the infant who is being labeled as having “asthma”… may be heart failure signs.
  • Listen to the older kid’s heart! (actually listen) Is there a murmur consistent with MR? Needs follow up and restricted physical activity until able to have ALCAPA ruled out.

 

References

Levitas A1, Krymko H, Ioffe V, Zalzstein E, Broides A. Anomalous Left Coronary Artery From the Pulmonary Artery in Infants and Toddlers Misdiagnosed as Myocarditis. Pediatr Emerg Care. 2016 Apr;32(4):232-4. PMID: 26414630. [PubMed] [Read by QxMD]

Rodriguez-Gonzalez M, Tirado AM, Hosseinpour R, de Soto JS. Anomalous Origin of the Left Coronary Artery from the Pulmonary Artery: Diagnoses and Surgical Results in 12 Pediatric Patients. Tex Heart Inst J. 2015 Aug 1;42(4):350-6. PMID: 26413018. [PubMed] [Read by QxMD]

Duan X1, Yu T, Wang F, Liu H, Sun J, Zhai R. Anomalous origin of the left coronary artery from the pulmonary artery in infants: imaging findings and clinical implications of cardiac computed tomography. J Comput Assist Tomogr. 2015 Mar-Apr;39(2):189-95. PMID: 25594385. [PubMed] [Read by QxMD]

Arunamata A1, Buccola Stauffer KJ2, Punn R1, Chan FP3, Maeda K4, Balasubramanian S2. Diagnosis of Anomalous Aortic Origin of the Left Coronary Artery in a Pediatric Patient. World J Pediatr Congenit Heart Surg. 2015 Jul;6(3):470-3. PMID: 26180168. [PubMed] [Read by QxMD]

Cabrera AG1, Chen DW2, Pignatelli RH3, Khan MS2, Jeewa A3, Mery CM2, McKenzie ED2, Fraser CD Jr2. Outcomes of anomalous left coronary artery from pulmonary artery repair: beyond normal function. Ann Thorac Surg. 2015 Apr;99(4):1342-7. PMID: 25725925. [PubMed] [Read by QxMD]

Lam JC1, Giuffre M1, Myers KA1. Late intervention in an asymptomatic pediatric patient with anomalous left coronary artery. World J Cardiol. 2014 Aug 26;6(8):874-7. PMID: 25228967. [PubMed] [Read by QxMD]

Sean Fox

I enjoy taking care of patients and I finding it endlessly rewarding to help train others to do the same. I trained at the Combined Emergency Medicine and Pediatrics residency program at University of Maryland, where I had the tremendous fortune of learning from world renown educators and clinicians. Now I have the unbelievable honor of working with an unbelievably gifted group of practitioners at Carolinas Medical Center. I strive every day to inspire my residents as much as they inspire me.

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1 Response

  1. John Hipskind says:

    Thanks again for putting out these amazing bits of information. Finding topics, summarizing them, summarizing them even further and all with a great sense of humor is really appreciated by myself and many of our colleagues in the trenches.

    John

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