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what’s a TAVI?

11 Apr

vck8sm5h Transcatheter Aortic Valve Implantation (TAVI) Reduces Mortality Rate Compared to Standard Therapy

RAGING HYPOTHETICAL:
–Hypotensive, elderly gentleman presents to your ED, records show he’s had a TAVI

–You nod your head with a reassurring look, then run to google…

–Next time you won’t need to – because you read this post.

WHAT’S A TAVI?

Transcatheter Aortic-Valve Implantation (TAVI) for patients with severe aortic stenosis who are not candidates for surgery.

What it looks like:

kdaesp1huv Transcatheter Aortic Valve Implantation (TAVI) Reduces Mortality Rate Compared to Standard Therapy

How it is placed: (so cool and worth watching)
The implantation procedure involves accessing a femoral artery, performing balloon valvuloplasty, then advancing the device across the native valve. During rapid right ventricular pacing, a balloon is inflated to deploy the valve and the frame.

Video animation: http://youtu.be/_eiI6S62zOs

Evidence it works:

At one year, the rate of death from any cause was 30% with TAVI vs. 50.7% with standard treatment (balloon aortic valvuloplasty and or medical therapy)

Not so good: TAVI had a higher incidence of strokes and major vascular complications compared to standard treatment, however this was included in rate of death.

Now you know đŸ™‚

Submitted by S. Morris.

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chest pain with recent negative stress test

27 Mar

EP MONTHLY EXCERPT:
–nice overview on stress tests from March 2011(see reference link)

DOES THE RECENT NEGATIVE STRESS MEAN THIS PATIENT CAN’T HAVE ACS?
–No.
–stress tests are good, not great

SOME ROUGH EXAMPLES:
–Sensitivity for single vessel CAD:

  • exercise ECG stress test ~68%
  • exercise nuclear stress test (thallium) 60-82%
  • exercise nuclear stress test (sestamibi) 82-97%
  • adenosine/dipyridamole nuclear stress 77-92%
  • dobutamine nuclear stress 80-100%

BOTTOM LINE:
–stress sensitivity is not perfect
–negative stress test does NOT rule out ACS

Reference(s): ep monthly article, picture

the TASER-ed patient

20 Mar

PHYSIOLOGY OF TASERS:
–nice article in Emergency Medicine News from Feb ’12 (link below)

HIGHLIGHTS:
–TASERs deliver electrical current to cause diffuse muscular contraction, thus incapacitating

–people who need to be TASERed may be drugged up, overexherted, or sustain trauma, so there are other things to think about

–in studies with healthy subjects, there were minimal (returning to baseline in 10 minutes) or no changes in pulse, 02 saturation, bicarb, lactate, electrolytes, troponin, EKGs, acidosis

EVERYTHING’S RELATIVE:
TASER joule output: 0.36-1.76 joules

RANDOM FACT:
–TASER stands for “Thomas A. Swift’s electric rifle”, after the developer’s childhood hero

BOTTOM LINE:
–asymptomatic, awake post-TASERed patient, unlikely to need routine labs/monitoring

Submitted by S. Lee.

Reference(s): EMN article, review article, taser joules, picture

posterior and RV myocardial infarction

17 Feb

Submitted by E. Hawkins.

cardiac tamponade and electrical alternans

7 Feb

POSSIBLE EKG FINDINGS IN CARDIAC TAMPONADE:
–sinus tachycardia
–low voltage
electrical alternans

ELECTRICAL ALTERNANS:

beat to beat alternation in QRS appearance
–related to back & forth swinging motion of the heart in the pericardial fluid (thought this was a nice way of picturing it)

Reference(s): uptodate.com: cardiac tamponadependulum, EKG

where do patient’s with Marfan Syndrome dissect?

24 Jan

AORTIC DISSECTION & MARFAN SYNDROME:
The major cardiovascular manifestation in Marfan Syndrome is a progressive dilatation of the ascending aorta, leading to aortic aneurysm formation and eventually to fatal aortic rupture or dissection. Aortic dissection in early adult life is the leading cause of death.

The ascending and descending aorta are both abnormal in Marfan Syndrome.

· The descending aorta is affected in two out of three patients during aortic dissection, and is the site of most complications which occur during follow-up.

· Aortic dissection limited to the descending aorta can occur in patients without dilatation of the ascending aorta.

–Dissection of the descending aorta was associated with dissection of ascending aorta in 43% and was isolated in 20% of cases.

BOTTOM LINE:
–dissections in Marfan involve descending aorta ~2/3 of the time, but these frequently involve the ascending aorta also
–if you have a patient with Marfan, and are worried about a dissection…worry about both (ascending/descending)
Submitted by J. Gullo.

Reference(s): PMID: 20232788, medscape article, picture

elevated troponin: what if its not an MI?

20 Jan

QUICK REVIEW:
–Myocardial necrosis indicated by elevated troponin is NOT always due to atherosclerotic CAD

–Troponin has high sensitivity for detecting very small amount of myocardial cell death

–Troponin is released in the blood due to irreversible as well as reversible cell damage AND does ≠ permanent myocyte damage

EXPANDED DIFFERENTIAL:
–Demand ischemia: sepsis/SIRS, hypotension, hypovolemia, SVT/afib, LVH

–Myocardial ischemia: coronary vasospasm, ICH/stroke, ingestion of sympathomimetic agents

–Direct myocardial damage: cardiac contusion, ICD shock, cardiac infiltrative d/o (amyloidosis), chemotherapy, myocarditis/pericarditis, heart transplant

–Myocardial strain: CHF, PE, PHTN, COPD, strenuous exercise

–Chronic renal insufficiency

Submitted by F. DiFranco.

Reference(s): Jeremias A. & Gibson M. Narrative review: alternative causes for elevated cardiac troponin levels when acute coronary syndromes are excluded. Annals of Internal Medicine. 142(9):786-791, May 2005.