Pulmonary arteriovenous malformation (PAVM) is an anomalous communication between the pulmonary arterial and venous vasculature which allows a right to left shunting of systemic deoxygenated blood. Currently, the prevalence of PAVMs is reported to be approximately 1 in 2,600 [1]. PAVM can be congenital or acquired and can coexist with hereditary hemorrhagic telangiectasia (HHT). Although this vascular abnormality may be present at birth, the manifestations usually appear later in life, frequently as dyspnea or embolic episodes.

Clinical presentation in PAVM patients is variable and includes asymptomatic hypoxemia [2], dyspnea [1], orthodeoxia [3], pleuritic chest pain [1], cyanosis, and clubbing. Hemoptysis and hemothorax are rare but could be fatal in pregnant patients, those with pulmonary hypertension, and in cases where PAVMs have feeders from the systemic arteries [4] [5]. Epistaxis and hemoptysis are seen more frequently in PAVM patients with HHT. The incidence of neurological manifestations is high in undiagnosed PAVM cases. Affected individuals could present with myocardial infarction, ischemic strokes secondary to paradoxical emboli, and intracranial abscesses [6] [7] [8]. The risk of migraines is also higher in PAVM patients with HHT [9] [10] [11].

• Unconsciousness

  […] and suffered a seizure during a practice, leading to him being diagnosed with AVM. [19] Actor Ricardo Montalbán was born with spinal AVM. [20] During the filming of the 1951 film Across the Wide Missouri, Montalbán was thrown from his horse, knocked unconscious [en.wikipedia.org]

• Collapse

  December 14, 2006. ^ "Mike Patterson's Collapse Reportedly Related To Brain AVM". sbnation.com. [en.wikipedia.org]

• Platypnea

  We describe a case of a rare clinical disorder, platypnea-orthodeoxia syndrome. A 57-year-old man was admitted with progressive dyspnea. [ncbi.nlm.nih.gov]

  In view of the platypnea-orthodeoxia and family history of PAVMs associated with HHT, a provisional diagnosis of PAVMs associated with HHT was made. [ispub.com]

  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. [orpha.net]

  The signs and symptoms of Pulmonary Arteriovenous Fistula include: Shortness of breath: Increased shortness of breath in upright position (platypnea), relieved by lying down Chest pain, cough that may contain blood in phlegm (hemoptysis) Migraine headaches [dovemed.com]

  If the patient becomes significantly desaturated in the upright position, the patient also demonstrates platypnea, which is dyspnea in the upright position, although this symptom is seen only in advanced cases. [emedicine.medscape.com]

• Pulmonary Disorder

  Conclusion Pulmonary AV malformation is a rare disorder and a rare cause of hemoptysis caused by congenital or acquired lesions in the lungs. [jacpjournal.org]

• Rhinorrhea

  […] sometimes seen as a complication of empyema, fibrosis, or pneumonia. cerebrospinal fluid fistula one between the subarachnoid space and a body cavity, such as from head trauma or bone erosion, with leakage of cerebrospinal fluid, usually in the form of rhinorrhea [medical-dictionary.thefreedictionary.com]

• Respiratory Distress

  Heart failure and respiratory distress also resolved after the procedure. [ncbi.nlm.nih.gov]

• Vascular Disease

  Arterial disease Cerebrovascular disease Cerebral disorder Human Congenital disease Central nervous system disease Nervous system diseases Instrumentation therapy Motor system disorder Vascular disease Venous disease Keyword (es) Adolescente Aneurisma [pascal-francis.inist.fr]

  Resumen Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) is an autosomal dominant vascular disease that can be associated with pulmonary arteriovenous fistulas. [repositorio.uchile.cl]

  Hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome) is an autosomal dominant vascular disease that can be associated with pulmonary arteriovenous fistulas. [scienceopen.com]

  He had no history of smoking or thrombotic vascular diseases. In physical exam the patient had normal vital signs. He had left-side facial palsy and hemi paresis. He was dysarthric and complained of diplopia when looking to the right side. [advbiores.net]

The diagnosis of PAVM should be suspected in individuals presenting with telangiectasis on mucous membranes or skin and unexplained clinical manifestations such as hypoxia or strokes. A family history of spontaneous epistaxis or hemoptysis should be elicited. If clinically relevant, all close relatives of the patient should be screened for PAVM and HHT [12]. On physical examination, telangiectasias may be noticed on the nose, lips, tongue [13], chest, and upper limbs. Other findings on examination include clubbing, occasionally cyanosis, and murmurs or bruits overlying the PAVM [14]. Pulse oximetry reveals oxygen saturation under 90% with a fall in partial oxygen pressure (PaO2) and oxygen saturation (SaO2) when the patient rises from a supine to an erect position (orthodeoxia). Pulmonary function tests may show a mild decrease in diffusion capacity and most patients with PAVM have a diminished tolerance to exercise.

Laboratory tests like a complete blood count in patients with chronic hypoxia will show elevated hemoglobin and hematocrit levels indicative of polycythemia but PAVM patients with HHT may have anemia due to recurrent episodes of epistaxis.

Findings on a plain chest X-ray include nodules or multiple soft tissue masses [15]. Definitive diagnosis of PAVM requires studies such echocardiography with contrast, radionuclide perfusion lung scan, computed tomography (CT), magnetic resonance imaging (MRI), or pulmonary angiography which is the gold standard [16]. Currently, conventional angiography is being replaced by digital subtraction angiography. CT findings could reveal a well-circumscribed and non-calcified nodule, serpiginous mass with vascular connections on non-contrast images [17], and feeding artery or draining vein on post-contrast images. MR angiography is useful to demonstrate vascular thoracic lesions in PAVM [18].

An echocardiogram with contrast is used to exclude other etiologies of a right-to-left shunt while a radionuclide perfusion lung scan is indicated if echocardiography with contrast is unavailable. However, pulmonary angiography continues to be the mainstay in the diagnosis of PAVM and should be performed, prior to embolization therapy, in all the lung lobes to detect multiple PAVMs.

• X-Ray Abnormal

  Therefore, the presence of P-AVF in stroke patients who have normal physical findings and no chest x ray abnormalities cannot be excluded. [jnnp.bmj.com]

• Chest X-Ray Abnormal

  Therefore, the presence of P-AVF in stroke patients who have normal physical findings and no chest x ray abnormalities cannot be excluded. [jnnp.bmj.com]

Large pulmonary arteriovenous fistula (PAVF) manifests as cyanosis and predisposes to serious complications of right-to-left shunt, and therefore necessitates early treatment. [ncbi.nlm.nih.gov]

Typically, individuals with mild conditions presenting no symptoms may not require any treatment. [dovemed.com]

With the increased blood flow in pregnancy such fistulas enlarge, occasionally giving rise to haemothorax, which generally has a poor prognosis. [ncbi.nlm.nih.gov]

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. [orpha.net]

Treatment and prognosis Treatment options include: trans-catheter coil embolization surgery (historically treated with surgery) Once successfully treated (embolotherapy, surgical resection), prognosis is generally good for an individual lesion. [radiopaedia.org]

[…] history with this disease Epistaxis common Telangiectasia of skin and mucus membrane GI bleeding TIA Stroke Cerebral abscess secondary to loss of pulmonary filter function Hemothorax 2° rupture of subpleural AVM Polycythemia Congestive heart failure Prognosis [learningradiology.com]

The analysis of a concomitant occurrence of these abnormalities may be useful in elucidating the etiology of pulmonary arteriovenous fistula. [ncbi.nlm.nih.gov]

Etiology The exact pathogenesis is still unknown. Although generally observed in the context of HHT, PAVMs may also be idiopathic. [orpha.net]

(See "Risk factors and epidemiology of coronary heart disease in end-stage renal disease (dialysis)" .) [uptodate.com]

Summary Epidemiology Prevalence is estimated at around 1/ 2,600. There is a minor female predominance. [orpha.net]

Lung India 33: 313-316 Zouboulis CC (1999) Epidemiology of Adamantiades-Behcet's disease. Ann Med Interne 150: 488-498. Erkan F (1999) Pulmonary involvement in Behcet disease. Curr Opin Pulm Med 5: 314-318. [omicsonline.org]

Robert.1989.Age related clinical profile of HHT in an epidemiologically recruited population. Am J. Med Genet.32: 291-297 5. [ispub.com]

[…] coils, particles, acrylates, or polymers introduced by a radiographically guided catheter, may be used in addition to neurosurgery or radiosurgery, but is rarely successful in isolation except in smaller AVMs. [15] Gamma knife may also be used. [16] Epidemiology [en.wikipedia.org]

Grasp the full scope of the pathophysiology of CHD with well-organized, expert guidance. Quickly search the contents online, download images in JPG or PPT format, and view 70 echocardiogram videos at expertconsult.com. [books.google.com]

This implies that the pathophysiology of the arteriovenous malformations in these conditions is dilation of the normal capillary bed. [emedicine.medscape.com]

[…] malformations [ edit ] In the lungs, pulmonary arteriovenous malformations have no symptoms in up to 29% of all cases. [5] Genetics [ edit ] Can occur due to autosomal dominant diseases, such as hereditary hemorrhagic telangiectasia. [ citation needed ] Pathophysiology [en.wikipedia.org]

PATHOPHYSIOLOGY In contrast to systemic arteriovenous malformation, PAVMs do not affect cardiac haemodynamics. 12, 13, 16 Cardiac output, cardiac index, pulmonary capillary wedge pressure, heart rate, blood pressure, and the electrocardiogram are usually [pmj.bmj.com]

The major concern when operating on a patient with a neurologically symptomatic pulmonary arteriovenous fistula (PAVF) is how to prevent a thromboembolic event during surgery. [ncbi.nlm.nih.gov]

Embolization is a standard medical procedure which is done to stop or prevent hemorrhage (bleeding) from an AVM. [clinicaltrials.gov]

1. Shovlin CL. Pulmonary Arteriovenous malformations. Am. J Respir Crit Care Med. 2014;190(11):1217-1228
2. Santhirapala V, Williams LC, Tighe HC, et al. Arterial oxygen content is precisely maintained by graded erythrocytotic responses in settings of high/normal serum iron levels, and predicts exercise capacity: an observational study of hypoxaemic patients with pulmonary arteriovenous malformations. PLoS ONE. 2014;9:e90777.
3. Santhirapala V, Chamali B, McKernan H, et al. Orthodeoxia and postural orthostatic tachycardia in patients with pulmonary arteriovenous malformations: a prospective 8-year series. Thorax. 2014;69:1046–1047
4. Shovlin CL, Sodhi V, McCarthy A, et al. Estimates of maternal risks of pregnancy for women with hereditary hemorrhagic telangiectasia (Osler-Weber-Rendu syndrome): suggested approach for obstetric services. BJOG. 2008;115:1108–15.
5. de Gussem EM, Lausman AY, Beder AJ, et al. Outcomes of pregnancy in women with hereditary hemorrhagic telangiectasia. Obstet Gynecol. 2014;123:514–520.
6. Clark K, Pyeritz RE, Trerotola SO. Angina pectoris or myocardial infarctions, pulmonary arteriovenous malformations, hereditary hemorrhagic telangiectasia, and paradoxical emboli. Am J Cardiol. 2013;112:731–734.
7. Kjeldsen AD, Tørring PM, Nissen H, Andersen PE. Cerebral abscesses among Danish patients with hereditary hemorrhagic telangiectasia. Acta Neurol Scand. 2014;129:192–197.
8. Shovlin CL, Jackson JE, Bamford KB, et al. Primary determinants of ischaemic stroke/brain abscess risks are independent of severity of pulmonary arteriovenous malformations in hereditary hemorrhagic telangiectasia. Thorax. 2008;63:259–266.
9. Thenganatt J, Schneiderman J, Hyland RH, et al. Migraines linked to intrapulmonary right-to-left shunt. Headache. 2006;46:439–443.
10. Marziniak M, Jung A, Guralnik V, et al. An association of migraine with hereditary hemorrhagic telangiectasia independently of pulmonary right-to-left shunts. Cephalalgia. 2009;29:76–81.
11. Post MC, van Gent MW, Plokker HW, et al. Pulmonary arteriovenous malformations associated with migraine with aura. Eur Respir J. 2009;34:882–887.
12. Haitjema TF, Disch TT, Overtoom C, et al. Screening family members of patients with hereditary hemorrhagic telangiectasia. Am. J. Med. 1995;99:519–524.
13. Plauchu H, de Chadarevian J-P, Bideau A, et al. Age-related clinical profile of hereditary hemorrhagic telangiectasia in an epidemiologically recruited population. Am. J. Med. Genet. 1989;32:291–297.
14. Dines DE, Arms RA, Bernatz PE, Gomes MR. Pulmonary arteriovenous fistulas. Pul Mayo Clin. Proc. 1974;49:460–465
    
15. Gill SS, Roddie ME, Shovlin CL, et al. Pulmonary arteriovenous malformations and their mimics. Clin Radiol. 2015;70 (1):96-110.
16. Guttmacher AE, Marchuk DA, White RI Jr. Hereditary hemorrhagic telangiectasia. N Engl J Med. 1995;333(14): 918-924.
17. Remy J, Remy-Jardin M, Wattinne L, Deffontaines C. Pulmonary arteriovenous malformations: evaluation with CT of the chest before and after treatment. Radiology. 1992; 182(3):809-16.
18. Maki DD, Siegelman ES, Roberts DA et al. Pulmonary arteriovenous malformations: three-dimensional gadolinium-enhanced MR angiography-initial experience. Radiology. 2001;219 (1): 243-246.