Vascular 2.53-2.60 Flashcards
Three vasodilatory substances? (generally antithrombotic too)
NO, PGI2, EDHF.
Four vasoconstrictory/prothrombotic substances?
ET-1, ATII, oxidants, TXA2
What counts as significant FHx for IHD?
Before 55 (M) or 65 (F) in first degree relative.
Troponin T significance?
More specific to cardiac muscle, but can be influenced by other things e.g. sepsis/PE (that damage heart).
Rapid-rule out criteria for troponins?
Measure on admission; >99th URL; repeat after 3 hours; need >10ng/L change AND at least 20% change for possible ACS
What to do if (in hs-cTnT) TnTA <99th URL?
If pain <6 hours, do TnT 3; if 6 hours or more then non ACS.
First investigations in ACS?
Serum lipids, glucose, U&E, ECG. (Echo is second line)
ABPI below 0.9?
Indicates some PAD
Causes of hyperuricaemia?
- Increased production (diet, alcohol, TLS, lymphoma etc)
2. Decreased excretion (diuretics [thiazide/loop], CKD, genetics, HTN)
When to treat hyperuricaemia?
Only when symptomatic ie gout or have complications; use allopurinol.
Best and worst prognosis re ECG changes?
T wave inversion alone is best. ST elevation alone worst initially; ST depression higher at six months; ST elevation AND depression highest
What if ECG non-diagnostic in ACS?
Repeat in 30 mins
When does Tn become detectable in ACS?
After 3 hours.
ABCDE of post ACS discharge?
A = antiplatelets and ACEI B = B blockers and BP C = cholesterol and cigarettes D = diet and diabetes E = education and exercise
When not to give fondaparinux in ACS?
High bleeding risk or angiography planned in next 24 hours
Angiography timescale?
In 90 hours, unless contraindicated, or unstable/high risk/STEMI (STAT)
Drugs that can cause/exacerbate HTN?
Cocaine, amphetamines, oral contraceptives, sympathomimetics (e.g. decongestants with phenylephrine), NSAIDs, systemic steroids (mineral/gluco), erythropoeitin, cyclosporin
BP and CO/PVR?
Either one or the other must be elevated to raise BP
Five factors that promote vascular hypertrophy and vasoconstriction?
Insulin, catecholamines, angiotensin,endothelin, GH (ie explains why acromegaly is a secondary cause of HTN)
Genetics and HTN?
Western black more predisposed, higher BP and mortality. Probably polygenic
HTN and sex?
HTN less common in premenopausal women than me (therefore hormones likely involved) but oestrogen/COC/HRT increases HTN?
Renin levels in essential HTN?
May be high; usually normal/low because of negative feedback
Insulin resistance and HTN?
Clear association, particularly in obese. Insulin is a pressor agent and increases levels of cataecholamines and renal sodium reabsorption
Endothelial dysfunction and HTN?
Reduced vasodilatory responses to NO?
ANS and HTN?
Increases SNS drive (particularly a feature in young HTNsives) will stimulated renin production, constrict arterioles and veins and increease CO.
Effects of angiotensin II?
- Increased sympathetic activity
- Increased tubular Na/Cl reabsorption, H20 retention, K+ excretion
- Increased aldosterone secretion
- Increased arterial vasoconstriction
- ADH release and therefore water retention.
(Net effect is increased circulating volume and therefore better perfusion so renin production should be reduced)
Renal contributions to BP control?
RAAS, medullipin (potent vasodilator; reduced levels in renal disease), renalase (metabolises circulating catecholamines)
Genetic links with phaeochromocytoma?
VHL, MEN2 (A and B), RET.
Investigating phaeohromocytoma?
Plasma mets and/or urinary mets/catecholamines to screen; need CT/MRI of head/neck/chest/abdomen to locaise. Rule out other causes. Usually do surgical resection.
Suspect Conn’s syndrome?
Low K+ and HTN and not on diuretic.
Causes of Conn’s?
2/3 is bilateral adrenal hyperplasia; 1/3 adrenal adeoma; rarely get adrenal malignancy or familial hyperaldosteronism.
Renin in primary vs secondary hyperaldosteronism?
Low in primary; increased in secondary because cardiac output usually low.
Genetics of adrenal adenoma (1/3 Conn’s)
40% have single genetic mutation (KCNJ5)
Screening Conn’s?
Screening considered in high BP with low K+, treatment resistant HTN, family members with condition, or adrenal mass. Measure aldosterone and do A:R.
Diagnosing Conn’s?
Do saline suppression/ambulatory salt loading test/fludrocortisone suppression test. Then image (CT); may need to have adrenal venous sampling to clarify if unilateral or bilateral (uni = adenoma therefore surgery; bi = medical treatment with spironolactone)
Tests in Cushings?
Measure ACTH, check cortisol, MRI brain, dex. suppression
Liddle syndrome?
Rare AD condition with amiloride-sensitive ENac hyperacitivity; get HTN, low K+, high HC03-, met alkalosis, low PRA and aldosterone
Difference in bloods between Liddle’s and Conn’s?
Liddle’s has low renin and aldosterone; Conn’s just low renin.
3 types of mineralocorticoid HTN?
- Conn’s = excess MR ligand
- Apparent mineralocoricoid excess (11bHSD2 defect)
- Liddle syndrome
Apparent mineralocorticoid excess? (RENIN SHOULD ALWAYS BE LOW; IF NORMAL THEN ALTERNATE DIAGNOSIS)
HTN due to genetic 11bHSD2 mutation; cannot transform cortisol to cortisone so get MR activation. Get low renin and aldosterone (-ve FB) Hypernanatraemia, hypokalaemia, HTN.
Diagnosis of AME?
Low renin, low aldosterone (as with Liddle) and high cortisol:cortisone
Diagnosis of Liddle?
Low renin, low aldosterone (or normal), normal cortisol:cortisone, then do genetics
Bloods in Conn’s?
High Na+, low K+, high HC032- = HYPERNATRAEMIC, HYPOKALAEMIC MET ALKALOSIS
Why do radiofemoral delay in HTN exam?
Coarctation of the aorta can cause HTN?
AD PKD?
Potentially lethal monogenic disorder. Large (ballotable) kidneys. High risk of CKD. Diagnosed usually with US/CT/MRI; can go genetic testing in some cases. Get increased SNS activity and HTN
Investigating HTN?
Exam, FBC, BP lying/standing/each arm, end organ damage (U+E, protein creatinine ration, ECG [LVH] fundoscopy), cholesterol/DM/BMI
Investigating HTN (2)
CXR, echo, plasma/urinary mets, renin-aldosterone ratio, renal US (polycystic/renal artery stenosis), MR angio (suspected renal artery stenosis), cortisol
Best Ix for renal artery stenosis?
MR angiography
DD renal artery stenosis?
Fibromuscular dysplasia; young women with severe HTN
Renal US in HTN?
Excludes polycystic kidneys and single shrunken kidney (could be renal artery stenosis)
Stage 1 HTN?
Clinic >140/90 AND ABMP/HBPM mean >135/85. Do not treat; lifestyle; arrange 24 hour monitor.
Stage 2 HTN?
Clinic >160/100 AND ABPM/HBPM mean > 150/95. Need speedyish 24 hour monitor, can treat.
Severe HTN?
Clinic >180 or diastolic >110; treat/admit urgently.
White coat HTN?
BP >/_ 149/90 in clinic, normal daytime mean <135/85. Does not mean normal risk!
Four principle checks of end-organ damage?
Urine (protein), blood (glucose, U&E, cholesterol), fundi, 12 lead ECG.
QRISK2?
Risk of MI/CVA in next 10 years (not for people with history of these)