Rare Hematology News

Disease Profile

Pulmonary arterio-veinous fistula

Prevalence
Prevalence estimates on Rare Medical Network websites are calculated based on data available from numerous sources, including US and European government statistics, the NIH, Orphanet, and published epidemiologic studies. Rare disease population data is recognized to be highly variable, and based on a wide variety of source data and methodologies, so the prevalence data on this site should be assumed to be estimated and cannot be considered to be absolutely correct.

Unknown

Age of onset

Childhood

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ICD-10

Q25.7

Inheritance

Autosomal dominant A pathogenic variant in only one gene copy in each cell is sufficient to cause an autosomal dominant disease

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Autosomal recessive Pathogenic variants in both copies of each gene of the chromosome are needed to cause an autosomal recessive disease and observe the mutant phenotype

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X-linked
dominant X-linked dominant inheritance, sometimes referred to as X-linked dominance, is a mode of genetic inheritance by which a dominant gene is carried on the X chromosome.

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X-linked
recessive Pathogenic variants in both copies of a gene on the X chromosome cause an X-linked recessive disorder

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Mitochondrial or multigenic Mitochondrial genetic disorders can be caused by changes (mutations) in either the mitochondrial DNA or nuclear DNA that lead to dysfunction of the mitochondria and inadequate production of energy.

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Multigenic or multifactor Inheritance involving many factors, of which at least one is genetic but none is of overwhelming importance, as in the causation of a disease by multiple genetic and environmental factors.

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Not applicable

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Other names (AKA)

Pulmonary arteriovenous fistula; Pulmonar arteriovenous aneurysm

Categories

Blood Diseases; Congenital and Genetic Diseases

Summary

The following summary is from Orphanet, a European reference portal for information on rare diseases and orphan drugs.
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Orpha Number: 2038

Definition
Pulmonary arteriovenous malformation (PAVM) describes an anatomic communication between a pulmonary artery and a pulmonary vein leading to a right to left extracardiac shunt that can be asymptomatic or can lead to varying manifestations such as dyspnea, hemoptysis, and neurological symptoms.

Epidemiology
Prevalence is estimated at around 1/ 2,600. There is a minor female predominance.

Clinical description
Clinical features vary widely but in most cases, PAVMs are asymptomatic because of successful physiological compensations (i.e. polycythemia, high cardiac output). The mean age for presentation is over 50ys of age, though lower if screening programs are utilized. Dyspnea, fatigue and exercise intolerance are more common in patients with concurrent conditions such as anemia, cardiac and/or respiratory diseases. Hemoptysis is rare, but is the most frequent cause of maternal death in pregnancy. Neurological manifestations including migraines, ischemic strokes/ transient ischemic attacks, and cerebral abscesses are attributed to paradoxical embolism through PAVMs. Tachyarrhythmias and angina may be present at diagnosis, although they usually reflect a more complex underlying pathology; particularly iron deficiency and/or visceral arteriovenous malformations (AVMs) due to underlying hereditary hemorrhagic telangiectasia (HHT). HHT is present in the majority of recognized cases of PAVMs (> 90 % in some series).

Etiology
The exact pathogenesis is still unknown. Although generally observed in the context of HHT, PAVMs may also be idiopathic. Much rarer etiological causes include cavopulmonary surgical corrections of cyanotic congenital heart disease; gestational trophoblastic disease; and arteriovenous fistulae induced by trauma.

Diagnostic methods
Diagnosis is based on imaging demonstrating one or more AVMs usually located in the lower lobes of the lungs. Although PAVMs may be clearly visible on chest x-rays, many are not, even when clinically significant. Computed tomography (CT) is generally considered the gold-standard investigation for diagnosing PAVMs. AVMs can be isolated or multiple, unilateral or bilateral. 'Simple' lesions consist of an aneurysmal venous sac communicating with a dilated feeding artery and draining vein. Other PAVMs are complex plexiform masses with multiple afferent and efferent vessels. Diffuse PAVMs are multiple small PAVMs affecting a single segment, or every segment of one or more lobes. Arterial partial pressure of oxygen (PaO2) and oxygen saturation (SaO2), are often low, and are inversely related to the size of the right to left shunt. Approximately 1/3 of patients demonstrate orthodeoxia, but platypnea is seldom observed.

Differential diagnosis
Differential diagnoses include pulmonary artery aneurysms, pulmonary varices, bronchoceles and vascular tumors.

Genetic counseling
Genetic counseling focuses on the presence of hereditary hemorrhagic telangiectasia (HHT). Since HHT can be difficult to diagnose, and familial PAVMs are recognized in non-HHT families, screening of first-degree relatives is common.

Management and treatment
Percutaneous transcatheter embolization of the pulmonary artery/ies feeding the PAVMs is the treatment of choice, irrespective of respiratory symptoms. Additional recommendations include judicious dental hygiene; antibiotic prophylaxis prior to dental and surgical procedures; optimization of iron status; and pregnancy-specific recommendations.

Prognosis
With appropriate management and interventions, prognosis is generally very good with many patients reaching their 9th and 10th decades of life. During pregnancy, however, there is a 1% maternal death rate. Difficult management issues arise in patients who continue to experience neurological complications, or when PAVMs acquire a systemic arterial supply, increasing the risk of hemoptysis.

Visit the Orphanet disease page for more resources.

Symptoms

This table lists symptoms that people with this disease may have. For most diseases, symptoms will vary from person to person. People with the same disease may not have all the symptoms listed. This information comes from a database called the Human Phenotype Ontology (HPO) . The HPO collects information on symptoms that have been described in medical resources. The HPO is updated regularly. Use the HPO ID to access more in-depth information about a symptom.

Medical Terms Other Names
Learn More:
HPO ID
80%-99% of people have these symptoms
Pulmonary arteriovenous fistulas
0004952
Telangiectasia
0001009
30%-79% of people have these symptoms
Dyspnea
Trouble breathing
0002094
Hemothorax
0012151
Hypoxemia
Low blood oxygen level
0012418
Ischemic stroke
0002140
Transient ischemic attack
Mini stroke
0002326
5%-29% of people have these symptoms
Abnormal thrombosis
Abnormal blood clot
0001977
Bacterial endocarditis
0006689
Brain abscess
0030049
Clubbing
Clubbing of fingers and toes
0001217
Cough
Coughing
0012735
Cyanosis
Blue discoloration of the skin
0000961
Epistaxis
Bloody nose
Frequent nosebleeds
Nose bleed
Nose bleeding
Nosebleed

[ more ]

0000421
Heart murmur
Heart murmurs
0030148
Hemoptysis
Coughing up blood
0002105
Iron deficiency anemia
0001891
Migraine
Intermittent migraine headaches
Migraine headache
Migraine headaches

[ more ]

0002076
Myocardial infarction
Heart attack
0001658
Palpitations
Missed heart beat
Skipped heart beat

[ more ]

0001962
Pleural empyema
0011919
Pulmonary arterial hypertension
Increased blood pressure in blood vessels of lungs
0002092
Pulmonary hemorrhage
0040223
1%-4% of people have these symptoms
Gastrointestinal infarctions
Death of digestive organ tissue due to poor blood supply
0005244
Liver abscess
0100523
Recurrent abscess formation
0002722
Seizure
0001250

Learn more

These resources provide more information about this condition or associated symptoms. The in-depth resources contain medical and scientific language that may be hard to understand. You may want to review these resources with a medical professional.

In-Depth Information

  • The Monarch Initiative brings together data about this condition from humans and other species to help physicians and biomedical researchers. Monarch’s tools are designed to make it easier to compare the signs and symptoms (phenotypes) of different diseases and discover common features. This initiative is a collaboration between several academic institutions across the world and is funded by the National Institutes of Health. Visit the website to explore the biology of this condition.
  • Orphanet is a European reference portal for information on rare diseases and orphan drugs. Access to this database is free of charge.