Cardiology I Flashcards
Xarelto
rivaroxaban
What is the mechanism of rivaroxaban
Selectively blocks active site of factor Xa, inhibiting blood coagulation
What is the blackbox warning associated with Xarelto
TX Discontinuation: increase risk of thrombotic event and stroke when D/C rivaroxaban in pts with non valvular atrial fibrillation: if must D/C rivraoxaban for reasons other than pathological bleeding, consider administering another anticoagulant.
Pradaxa
Dabigitran etexilate
What is the mechanism of dabigitran
directly, reversibly inhibits thrombin
What are the two ways to cardiovert a patient
- Chemically
2. Electrically
Where are 90% of cardiac blood clots formed
atrial appendage
Is removal of the atrial appendage a viable surgical treatment for Afib
Not as the sole means of indication to surgery; will only assist in thromboembolic event but will not affect rate or rhythm
Tikosyn
dofetilide
Considered to be the best antiarrhythmic
When is tikosyn indicated
Atrial fibriliation flutter
What is the mechanism of dofetilide
prolongs action potential phase 3 (class III antiarrhythmic)
Where do the foci for afib typically originate
close proximity to the pulmonary veins
What are the surgical treatment options for Afib
- Endocardial abblation: circular ablation around the pulmonary veins. Lower outcome success
- Maze procedure: epicardial abblation. Numerous incisions leading to scar formation
- Hybrid: epicardial and endocardial abblation. Still considered to be experimental and limited data available on the success rate.
What are the limiting factors for anticoagulants other than heparin and warfarin
renal clearance
What is cardiac FFR
(FFR) is a technique used in coronary catheterization to measure pressure differences across a coronary artery stenosis (narrowing, usually due to atherosclerosis) to determine the likelihood that the stenosis impedes oxygen delivery to the heart muscle (myocardial ischemia).[1]
Fractional flow reserve is defined as the pressure behind (distal to) a stenosis relative to the pressure before the stenosis. The result is an absolute number; an FFR of 0.50 means that a given stenosis causes a 50% drop in blood pressure. In other words, FFR expresses the maximal flow down a vessel in the presence of a stenosis compared to the maximal flow in the hypothetical absence of the stenosis.
What is IVUS
intravascular ultrasound
a medical imaging methodology using a specially designed catheter with a miniaturized ultrasound probe attached to the distal end of the catheter. The proximal end of the catheter is attached to computerized ultrasound equipment. It allows the application of ultrasound technology to see from inside blood vessels out through the surrounding blood column, visualizing the endothelium (inner wall) of blood vessels in living individuals.
Plavix
clopidogrel
What is the mechanism for clopidogrel
Irreversibly binds to P2Y12 adenosine diphosphate receptors, reducing platelet activation and aggregation
What are the indications for clopidogrel
Acute coronary syndrome
Thrombotic event prevention
What are bare metal stents
a vascular stent without a coating (as used in drug-eluting stents). It is a mesh-like tube of thin wire. The first stents licenced for use in cardiac arteries were bare metal - often 316L stainless steel. More recent (‘2nd generation’) stents use cobalt chromium alloy.
What are the types of exercise stress types
- Bruce
- Cornell
- Naughton
Discuss the bruce protocol
The Bruce protocol is generally preferred for office-based exercise testing largely because it has been carefully validated [14]. The protocol is divided into successive three minute stages, each of which requires the patient to walk faster and at a steeper grade. Stage I has at an incline of 10 percent and a speed of 1.7 miles per hours; stage II progresses to an incline of 12 percent and a speed of 2.5 miles per hour (table 8). The determinants of the end of the protocol are discussed below. (See ‘Test endpoints’ below.)
The initial work load in stage I may occur too suddenly for some individuals, and an optional stage 1/2, in which the work load is lower than the usual first stage of the Bruce protocol, may be added at the beginning.
The modified Bruce protocol can be used for risk stratification of patients after an acute coronary syndrome (myocardial infarction or unstable angina) and in sedentary patients in whom the standard Bruce protocol may be too strenuous. The modified protocol adds two low-workload stages, both of which require less effort than Stage 1, to the beginning of the standard Bruce protocol.
Discuss the cornell protocol
The Cornell protocol was developed for use with computerized ST/HR slope determination, a possibly improved method of quantitative exercise electrocardiography [15,16]. The ACC/AHA guidelines concluded that the ST/HR slope (the rate-related change in exercise-induced ST segment depression) has not yet been validated, but that it could prove useful in patients with borderline or equivocal ST responses, such as ST segment depression associated with a very high exercise heart rate [2].
In the Cornell protocol, each stage of the Bruce protocol is divided into two smaller and shorter stages. Although this was done to provide more data points for the computerized ECG analyses, the protocol is also more applicable to patients with limited exercise tolerance because of the smaller workload increments.
Discuss the naughton protocol
The Naughton protocol is often used in post-MI exercise testing to classify patients into high-risk and low-risk categories and to determine optimal treatment strategies [17]. This protocol is also used for functional exercise testing with gas analysis techniques to measure oxygen uptake and VO2max. (See “Functional exercise testing: Ventilatory gas analysis” and “Exercise capacity and VO2 in heart failure”.)
In patients who have not been completely revascularized, two different protocols have been commonly used:
A predischarge submaximal test (modified Bruce or Naughton protocol). The 2004 ACC/AHA guidelines on ST elevation MI suggested that such testing can be performed as early as three to five days in patients without complications [18]. No changes to this approach were made in the ACC/AHA 2007 focused update [19].
A traditional symptom-limited exercise test, in which the test is not terminated for a target heart rate. The 2004 ACC/AHA guidelines for the management of ST elevation MI concluded that such testing is appropriate at five days or later [18] and the 2007 guidelines of unstable angina and non-ST elevation MI recommended testing at three to five days [20]
Name the loop diuretics
Bumetanide
torsemide
ethacrynic acid
furosemide
bumex
bumetanide
What is the mechanism of metazolone
inhibits cortical diluting site and proximal convoluted tubule sodium resorption
demadex
torsemide
lasix
furosemide
Betapace
sotalol
What is the mechanism of sotalol
non-selectively antagonizes beta-1 and beta-2 adrenergic receptors; prolongs action potential phase 3 (class III antiarrhythmic)
What testing is available for patients with palpitations
- EKG
- Echo
- Holter or Event monitor
What is the difference between a holter and an event monitor
Holter Monitor is worn continuously for 48 hours and can not be taken off.
Event monitor is worn for 14-28 days and only records the events when the patient activates the monitor