Pulmonary arteriovenous malformation, also known as pulmonary arteriovenous fistula/aneurysm, cavernous angioma of the lung, and pulmonary telangiectasia, is an irregular communication between arteries and veins within the lungs. It permits blood from the systemic venous circulation to bypass the process of pulmonary gas exchange. This anomaly leads to asymptomatic hypoxemia and other complications like paradoxical emboli and strokes.
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 . 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 , dyspnea , orthodeoxia , pleuritic chest pain , 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  . 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   . The risk of migraines is also higher in PAVM patients with HHT   .
Entire Body System
- Congestive Heart Failure
This is the opposite of orthopnea which is commonly present in congestive heart failure. [healio.com]
Heart Failure (CHF) (see Congestive Heart Failure, [Congestive Heart Failure]): due to intrapulmonary shunt Endocarditis (see Endocarditis, [[Endocarditis]]) Prognosis Mortality Rate : 4-22% in untreated symptomatic cases Spontaneous Regression of [mdnxs.com]
heart failure Prognosis After embolization, show about 96% of AVMs were subsequently undetectable 11% mortality Pulmonary AVM. [learningradiology.com]
Typical signs at presentation include cyanosis, murmur, and congestive heart failure. Abnormality on chest x-ray is common with cardiomegaly, oligemia, and focal pulmonary density. [link.springer.com]
We believed that “IDC, congestive heart failure” cannot explain the patient’s cyanosis, so CT angiography was obtained to detect other pulmonary diseases. [jtd.amegroups.com]
This approach is costly, inconveniences the patient, and may lead to noncompliance with embolotherapy. [ncbi.nlm.nih.gov]
This case is being reported since the association of large PAVM and tuberculosis is very rare, and both could present with hemoptysis. [ncbi.nlm.nih.gov]
He presented to ED with a spurious hemoptysis of about 400 ml. He was not on regular follow-up for RHD and refused any history of fever. [jacpjournal.org]
It usually presents between the fourth and sixth decades with epistaxis, dyspnea, hemoptysis or stroke. We describe a patient who developed an enlarging lung mass and hemoptysis secondary to pulmonary arteriovenous malformation. [slideshare.net]
Platypnea is associated with orthodeoxia which is oxygen desaturation that occurs while upright and improves while supine. [healio.com]
(see Platypnea-Orthodeoxia, [[Platypnea-Orthodeoxia]]) Orthodeoxia: hypoxemia with upright position Platpnea: dyspnea with upright position Physiology: since vascular dilatations are basilar-predominant, upright position increases gravity-dependent blood [mdnxs.com]
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]
It can present with dyspnea, hemoptysis, and platypnea. Most are due to underlying hereditary telangiectasia ( 4 ). We report a case of a 15-year-old girl with sarcoidosis found to have pulmonary AVMs, an extremely rare complication. [frontiersin.org]
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
disorders.  Two reports published in Japan in the year 2011 and 2015, where the preoperative diagnosis on chest imaging was made as PAVM but histopathology was suggestive of an alternative diagnosis, in the above-mentioned cases lung cancer and lung [jacpjournal.org]
His mother related a history of orthodeoxia with an increase in cyanosis when her infant is embraced and decrease in cyanosis when lying on the back. [panafrican-med-journal.com]
We report a 12-year-old girl who presented with exertional dyspnoea, cyanosis and clubbing since the age of five years, and multiple pulmonary arteriovenous malformations. [ncbi.nlm.nih.gov]
Wiggins Summary Pulmonary arteriovenous malformation (PAVM) is a rare cause of cyanosis in the newborn with nine previously reported cases. Typical signs at presentation include cyanosis, murmur, and congestive heart failure. [link.springer.com]
- Heart Disease
Simultaneous treatment of pulmonary AV malformation with rheumatic heart disease. Thorac Cardiovasc Surg 2009;57:174-6. [Figure 1], [Figure 2], [Figure 3] [jacpjournal.org]
A correctable form of cyanotic heart disease; an additional cause of cyanosis with left axis deviation. Circulation 31 :762–767 Google Scholar 8. Milovic I, Oluic D (1989) Congenital pulmonary arteriovenous fistula with hemothorax in a neonate. [link.springer.com]
Glenn and Fontan procedures for cyanotic congenital heart disease) 7 actinomycosis : thoracic actinomycosis infection Fanconi syndrome metastatic thyroid carcinoma tuberculosis 13-14 ( Rasmussen aneurysm ) A number of modalities are available for the [radiopaedia.org]
Other conditions that are less commonly associated with PAVM include liver disease (mainly liver cirrhosis ), certain forms of congenital heart disease, chronic infections, and metastatic thyroid cancer. [rarediseases.info.nih.gov]
- Systolic Murmur
A35-year-old white woman with a history of migraine headaches and a grade 2 systolic murmur presented with symptoms of slurred speech, left-sided facial droop, and left hemiparesis after a hysterectomy. [circ.ahajournals.org]
The significant findings were central cyanosis and a systolic murmur best heard at the apex and radiating to the axilla. Chest radiography revealed a right lower lobe lobulated mass. [pmj.bmj.com]
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 . On physical examination, telangiectasias may be noticed on the nose, lips, tongue , chest, and upper limbs. Other findings on examination include clubbing, occasionally cyanosis, and murmurs or bruits overlying the PAVM . 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 . 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 . 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 , and feeding artery or draining vein on post-contrast images. MR angiography is useful to demonstrate vascular thoracic lesions in PAVM .
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.
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