Vascular Disorders Flashcards
Name 4 classic features of hereditary hemorrhagic telengectasia
(Hint: VETH)
- Pulmonary, hepatic, cerebral spinal AVM (visceral lesions)
- Epistaxis (spontaneous and recurrent)
- Gastrointestinal telengectasia ( considered a visceral lesion by Curaçao criteria)
- Mucocutaneous telengectasia
- Family history- first degree relative with HHT
- Iron deficiency anemia (not a part of CC but considered classic clinical feature)
Curaçao criteria - >3definite 2possible 1 or less unlikely
List three physiologic consequences of Arteriovenous malformations
- Shunt, hypoxemia
- Risk of rupture or bleeding
- Loss of immune and embolus filtering.
- Aneurysm formation
- High output cardiac failure
JL notes
Describe the pathophysiology of HHT
Genetic defects disrupt the production of intact proteins involved in the TGFb signaling pathway. Proteins such as endoglin and ALK1 are abundantly expressed on vascular endothelium, and dysfunction results in defects of the vascular wall- resulting in Avm, telengectasis and epistaxis. Clinical consequences include shunt, Gi and mucocutaneous bleeding, and emboli phenomenon
Risk factors for hemorrhage with pulmonary AVM
Pregnancy
Pulmonary arterial hypertension
Systemic arterial supply has developed
UTD
List 5 causes of pulmonary AVM
- Genetic- HHT
- Infection- actinomycetes, TB, shistomiasis
- Systemic disease- mitral stenosis, cirrhosis, fanconi syndrome
- Metastatic thyroid cancer
- Trauma
JL notes
You see a new patient with suspected HHT. Who needs screening for cerebral AVM? What is the annual risk of bleeding?
- Definite or probably HHT- 2 curaçao criteria (veth)
2. Risk of bleeding 0.5%. Risk of rupture 2%
What is the initial guideline recommended screening test for pulmonary AvM in HHT?
If negative, when is this repeated?
Trans thoracic contrast enhanced echo
+ with bubbles in left atrium, but >30 bubbles considered +true positive. Pulmonary or non cardiac AVM is suggested by bubbles after 3-7 cardiac cycles
If TTCe is not available ct is acceptable (not first due to extra radiation)
Repeat
- After puberty
- Before and After pregnancy
- Every 5-10 years
BMJ 2011 HHT
When should PAVM be treated in HhT?
Feeding artery diameter of > or = 3mm
What lifestyle and non pharmacological recommendations are given to patients with documented PAVM?
- Antibiotic prophylaxis should be given for procedures with a risk of bacteremia
- No scuba diving
- Air filters should be placed on IV lines and intravenous air should be avoided
BMJ 2011
List 5 consequences of hepatic AVM common to HHT
- High output heart failure
- Portal hypertension
- Biliary failure- jaundice, abdominal pain, elevated liver enzymes
- Encephalopathy
- Intestinal arterial steal - ischemia
In a patient with genetic confirmation of HHT - what are the recommended screening tests for AVM
- cerebral avm - mri+contrast
- Pulmonary avm - tte+ constrast
- GI -bleeding, hgb + hct
Liver US only in symptomatic pts
CT chest if echo not available or positive
PVOD - list 3 CT findings, and 3 non radiographic features
CT findings - Mediastinal adenopathy, interlobular septal thickening, centrilobular GGO
Non radiographic - Reduced DLCO, clubbing, Hypoxemia and symptoms out of keeping with percieved disease extent,
*Others: pulmonary edema with vasodilator testing, GEnetic causes, occupational exposure to organic solvents
List 4 classes of oral drugs in non-vasoreactive PAH
Endothelin receptor antagonists - ambrisentan
Phosphodiesterase 5 inhibitors - sildenifil
Guanylate cyclase stimulator - Riociguat
Prostacyline Receptor Agoinst- selexipeg
