Hemodynamics #2 Flashcards
Mixed Angina
Stable & variant Angina
Variant Angina
Spontaneous CP on rest or early morning, coronary spasm , can lead to infarction
Nitric Oxide
Required for vasodilation, normally released by endothelium. Atherosclerosis makes endothelium dysfunctional, malfunctioning intrinsic nitric oxide production. Nitro donor (nitro) quickens release of nitric oxide.
Nitro results in venous pooling, decreases which cardiac pressures?
Preload and LVEDPs
Nitro benefits
Decreased workload on ventricle, decreased ventricular wall tension, does not effect sympathetic tone other than decreasing myocardial O2 demand = decreased pain = decreased sympathetic tone.
Morphine benefits
- Decrease pain = decrease sympathetic tone = decrease workload on heart
- Histamine release (potent vasodilator)
CorrPP needs to be at least what to perfuse whole heart…
50
CorrPP = DBP - PCWP
Increase in wedge will decrease CorrPP
What pressure pushes blood into the coronary arteries?
Diastolic Blood Pressure
Beta Blocker Benefit in AMI
- Decreases HR and contractility = decrease workload.
- increases diastolic filling times.
- improves ejection fraction & SV
Beta blockers used and considerations
- Can be detrimental in acute phase.
- Tx unnecessary tachycardia. Do not bring down compensatory tachycardia.
- Treat pain 1st
- metoprolol & carvedilol (coreg), esmolol
Which beta blocker is the only beta blocker administered to CHF
carvedilol (coreg)
Ca channel blockers & AMI
Hydralazine
- dilates coronary arteries/collateral vessels
- at cost of decreasing myocardial contraction & conduction.
- Detrimental if heart is not beating fast enough or putting out enough volume.
3 phases of clot prevention & lysis
1- stops clots from forming
2- stop formed clots in their tracks
3- breaks down existing clots
Phase 1 examples
ASA
- inhibit platelet aggregation
- indefinitely poisons platelets by preventing release of thromboxane A2 (platelet interaction)
Glycoprotein IIb/IIIa inhibitors
- prevents common pathway by preventing plately interaction w/ other platelets.
- integelin, abciximab(RePro), tirofiban (aggrastat)
Phase 2 example
Heparin
- Prevent clot from further clotting & clumping
- prevents conversion of fibrinogen to fibrin
- prevents net from forming and stabilizing clot
- prevents formation of future clots
Phase 3 example
Fibrinolytics
- activates plasminogen to plasmin
- normal process to break down clot
- activates it faster than normal
- TPA (tissue plasminogen activator), retrovase, streptokinase, TNkase
Thrombolytic relative contraindications
HTN, recent trauma, pregnancy
Thrombolytic Absolute contraindications
Active internal bleeding, suspected aortic dissection, known intracranial neoplasm, pH hemorrhagic CVA, any CVA in past year.
Pacing complication: Over Sensing
Sensing activity that is not there, false or not productive and not pacing as a result
Pacing complication: Failure to Sense
Failure to pick up low amplitude QRS complexes and pacing over them. Potential for R on T
Other Pacing complications
Failure to capture (electrolyte disorder), myocardial penetration or perforation (tamponade/Becks triad)
-treatment (early) force fluids (late) pericardial centesis.
Pacing verification of electrical and mechanical capture
Electrical: t-wave of opposite polarity following wide bizarre complex
Mechanical: heart tones
