Cardiology questions Flashcards
What is the Bruce Protocol? What is a MET
Exercise stress test with a set of speed and elevation setting devised to achieve a specified target. The modified Bruce protocol adds two stages below I.
1 MET = 3.5ml of oxygen/kg/min corresponds to a sitting resting postion
3-5 METS = light walking
5-7 METS = shoveling snow
9 METS = playing squash
What is a positive stress test
Abnormal symptoms: chest pain, dyspnea, or syncope at less then 5 METS
Abnormal ECG: ST depression > 2 mm down sloping at < 6 METS, ST elevation, or arrhythmias
Abnormal blood pressure response: hypotension (a drop in SBP of 10 or more), inability to achieve SBP > 120
abnormal heart heart response: Inability to achieve a HR of 85% or more of expected, or bradycardia
Inability to achieve 6 METS
What is post pericardiotomy syndrome
Clinical entity caused by non-infectious inflammation of the pericardium after heart surgery
symptoms: Malaise, fever, pericardial rub, and chest pain
Investigation: ECG, non-specific chest leads ST elevation, Cardiomegaly on CXR and leukocytosis
It occurs one to two weeks after surgery and may last up to 6 to 8 weeks. Usually self limited, however, NSAIDS may help (ASA 650 mg po QID). Steriods are not indicated.
What are risks for perioperative stroke given degree of carotid stenosis
Carotid stenosis < 50% risk about 2%
Carotid 50 to 80% risk is 10%
carotid stenosis > 80% the risk 11 to 19%
Describe Heparin Induced Thrombocytopenia and classify
HIT is a clinical entity classified by a drop in platelet count attributable to the use of Heparin.
Results from IgG antibody against Heparin-PF4 complex.
Binding of the IfG antitbody to the platelets Fc receptor and PF4 leads to aggregation and consumption.
Type 1 HIT: mild drop in plt count > 100 000 without evidence of thrombosis Management is continued monitoring only
Type 2 HIT: moderate to severe drop in plt count to < 100 000 without evidnece of thrombosis. The management is to stop heparin, alternative anticoagulation and monitor for thrombosis
Type 3 HIT: HIT WITH evidence of thrombosis: management
Stop hepaiir/alternative anticoagultion/echo/vascular dropplers/check Anti-PF4/ treat ischemia
What are interesting facts of amio
Take 2 to 3 days to really work
Elimination half life is 25 to 100 days
interferes with metabolism of digoxin and warfarin
List side effects of amiodarone toxicity
Pulmonary chronic interstitial pneumonitis (most common) organizing pneumonia (ARDS) dry cough, malaise, Thyroid Cardiac arrhythmias Hepatitis transient rise in LFT cirrhosis and liver failure is rare Occular changes Skin changes GI--nause sleep/tremor/peripheral neuropathy
How do statins work
Inhibits the conversion of HMG CoA to mevalonate, the rate limiting step of cholesterol biosynthesis
LDL lowers by 30%
HDL increase by 5 to 10%
TG decrease by 20-40%
Treatment of a patient refractory to medical therapy for atrial fibrillation
AV node ablation withe VVIR PPM Pulmonary vein mapping and isolation surgical maze atrial pacing Implantable atrial defibrillator
CCS Classification –Hurst
Class I: Ordinary physical activity such as walking and climbing stairs does NOT cause angina
only angina with strenous or prolonged exertion
Class II: Slight limitation or ordinary activity
walking on level ground or > 2 flights of stairs
Class III: Marked limitation of ordinary physical activity
less then 2 flight of stairs
Class IV: inability to carry on ANY physical activity without discomfort
This pain should be less then 15 minutes because if greater them its unstable angina
NHYA classification
Class I—No symptoms
Class II- symptoms only with ordinary activity
Class II–symptoms with less then ordinary actitivity
Class IV- symptoms at rest
List 8 contraindications to thrombolytic therapy
Intracranial hemorrhage (any prior)
Known structural cerebral vascular lesion (AVM)
Malignant intracranial neoplasm
Ischemic CVA within 3 months
Suspected aortic dissection
Active bleeding
signficant closed head or facial trauma in last 3 months
What is classification of Calcium channel blockers
Dihydropyridines predominatly vasodilators little or no effect on contractility or conduction amlodipine non-hydropyridines reduce vascular permeabilty less potent vasodilators inhibit AV node conduction verapamil
What is the mechanism of action of nitrates and how do they reduce angina
dilate veins, arteries, and coronaries by relaxing smooth muscle
most anti-ischemic effect from systemic vasodilation that decreases myocardial oxygen demand rather than increase coronary artery blood flow
nitrates cause predomonatly venodilation, lowering preload thus decrease LVEDP, and decrease myocardial demand
What is relationship if Coronary artery calcium and coronary artery stenosis
0 — No identifiable disease
1 to 99– mild disease
100 to 399–modeate disease
> 400 severe disease
What are IVUS cut offs
an IVUS mean lumen diameter of < 2.8 mm or MLA < 6mm2 suggets a physiologically significant lesion and identify patients who may benefit from revascularization.
If IVUS MLA is >7.5 to 9 mm, revascularization may be safely deffered.
IVUS MLA between 6 to 7.5mm2 should be interpreted in conjunction with the patients clinical history, stress testing, or FFR>
How do you calculate pulmonary vascular resistance
PVR = PAP - PCWP/Cardiac output
How do you calculate Systemic vascular resistance
SVR = MAP - RAP/cardiac output
RAP = right atrial pressure
What is post pericardiotomy syndrome
non-infectious inflammation of the pericardium after heart surgery
signs
malaise, fever, pericardial rub, chest pain , leukocytosis, non specific ST elevation
occurs 1 to 2 weeks after surgery lasts up to 8.
self limited, NSAID
What are targets for LDL in patients
LDL:
Low risk pt < 4.5
Moderate risk < 3.5
high risk < 2.5
What are targets for Total Chol:HDL ratio
Low risk < 6.0
moderate < 5.0
High risk < 4.0
What are different agents for elevated LDL, TG< and depressed HDL
Statins: decrease LDL, increase HDL, and decrease total ratio
Resins: decrease LDL and increase HDL
Fibrates: decrease TG and increase HDL
Niacin: increase HDL (mostly) and decrease LDL and decrease TG
What is the evidence of PTCA and what are definitions
Primary PTCA: as initial method of reperfusion
↓ reinfarction and death and intracrancial hemorrhage
However, only in centers able to do 1˚ PTCA
Rescue PTCA: done following recurrent angina or HD instability following thrombolytic Rx
Immediate PTCA: performed in conjunction w/ thrombolytic Rx
ECSG/TAMI/TIMI IIA: does not improve clinical outcome; also ↑ risk of bleeding
Delayed PTCA: occurs during the intervening hospitalization
does not improve clinical outcome in pts w/ no ischemia on stress testing (TOPS)
Elective PTCA: following thrombolytic Rx and med mgt when positive stress test is obtained during same hospitalization or soon thereafter
TIMI IIB: thrombolytic Rx followed by PTCA in pts w/ symptomatic or provokable ischemia is appropriate
Cardiogenic shock: 1˚ PTCA improves survival to 40-60%. In hosp survival 70%. W/in 6h of onset of shock → ↑ 1yr survival
What is IVUS
allows visualization of the coronary arterial wall by using a minature transducer at the end of a flexibile catheter which emits u/s in 10 to 40MHz.
useful in delineating plaque morphology and distribution
Summary of IVUS
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Summary of CT angiogram for assessing coronary disease and calcium score
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Exercise stress testing
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Mibi scan
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What is metabolic syndrome
clinical entity associated with increased risk of atherosclerotic coronary artery disease, is components are:
Abdominal obesity
Insulin resistance
Low HDL
Hypertension
