Flashcards in Cardiac Diagnostics and Therapies 1 Deck (32)
-whats included in a transthoracic echo?
benefits: rapid, accurate, readily available, portable, noninvasive
-included: M-mode, 2d cardiac images, color flow doppler
What information is provided from Echocardiography?
-cardiac structure: chamber size, muscle thickness
-Function: ejection fraction, wall motion
-Aortic root size
-Intracardiac blood flow
-whats an advantage to this?
-gives a more detailed evaluation than echocardiography.
-Valve function (for further eval beyond TTE and used in the operating room during valve replacement)
-endocarditis (looking for vegitations)
Tests for the work up of the suspected of arrhythmias
Describe the Holter monitor? Describe the event monitor.
-patient records a diary of activities and sx
-worn for a month
-patient triggers the monitor to record during sx
Ambulatory cardiac monitors are useful to investigate the following.....
-to assess rate control or determine % atrial fibrillation
-intermittent dizziness or light headedness that does not seem to be orthostatic
-evaluate for suspected or known arrhythmias
-what is this?
-indications for this
-uses multipolar electrode catheters placed in the venous/arterial circulation and advanced to various positions in the heart, attempts to induce arrhythmias. Measures response to pharmacologic/pacing device intervention.
-records an internal EKG
-survivors of sudden cardiac death that was not related to an ischemic event
-palpations preceeding syncope
Interventions for arrhythmias and systolic heart failure
-Therapy for advanced heart failure
-how does this work?
-provides electrical stimuli to cause cardiac contraction when intrinsic cardiac activity is anappropriately slow or absent.
What is the only treatment for bradyarrhythmias?
What are the different types of pacemakers?
When are external pacemakers used?
-in emergencies as a bridge therapy.
-used for initial stabilization of hemodynamically sifnificant bradycardia
-how does this work?
-placement of pacemaker involves one or more pacing wires within the chambers of the heart. One end of each wire is attached to the muscle of the heart, the other end is screwed into pacemaker.
-single lead (paces ventricle)
-dual chamber (can pace atrium or ventricle)
With dual chamber pacemaker what feature of the heart still needs to be intact for this to work?
-the AV node
Absolute pacemaker indications
-sick sinus syndrome
-symptomatic sinus bradycardia
-afib with slow ventricular response
-3rd degree heart block
-chonotropic incompetence (inability to increase heart rate to match exercise.)
What are the main functions of pacemakers?
-sensing: "listening" to the hearts native electrical rhythm
-pacing: device will stimulate the ventricles of heart with set amount of energy,
with a single wire pacemaker will you have p waves?
no P waves because this is single wire pacing in the right ventricle.
What is a Pacemaker Complication? WHy does this happen?
-patient feels worse after pacemaker placement.
-presents with worsening CHF sx
-d/t loss of atrioventricular synchrony, pathway now reversed and ventricular origin of beat.
Biventricular pacing is reserved for therapy in ____.
Describe this type of pacemaker.
What are some advantages to this?
advanced heart failure.
-the biventricular pacing devices have a third lead that is designed to conduct signals directly into the left ventricle. All 3 leads create a synchronized pumping of the ventricles
-Advantage: gets rid of asynchrony between ventricles, may increase EF.
-how does this differ from a pacemaker?
-pacing, cardioversion, and defibrillation to treat brady and tachy arrhythmias
-this differs from a pacemaker in that it has two levels of energy to shock the pt, a lower energy for tachy/brady and a higher energy for severe arrhythmias such as when the heart is "quivering."
-previous cardiac arrest
-pt with undetermined origin or continued VT of VF despite medical interventions
-cardiomyopathy (EF less than 35%)
In case of emergency you can still use an external defibrillator with a ICD/pacemaker, true or false?
-True, the sternal paddles should be placed a safe distance from the pulse generator.
Left Ventricular Assist Device
-when do you use this?
-how does this work?
-indications: severe systolic heart failure
-use this as a bridge to transplant or in pts who are too old for heart transplant.
-pump of LVAD takes over the work of the left ventricle, implantable tubes that connect to an external battery pack.
Percutaneous Coronary Intervention
-Angioplasty (ballooning open a blood vessel)
-Intracoronary stent placement
--bare metal stents
--drug coated stents
What is Balloon Angioplasty? Major limitations?
-balloon catheter is passed through the guiding catheter to the area near the narrowing, balloon is inflated compressing the plaque against the artery wall. Once plaque compressed and the artery has been opened, the balloon catheter is deflated and removed.
Limitation: restenosis occurs 30-40% in first 6mo.
Describe Intracoronary stent placement
stent introduced into blood vessel on a balloon catheter and advanced into blocked area of the artery. balloon inflated and causes stent to expand until it fits the inner wall of the vessel. Balloon is then deflated and drawn back. Stent stays in place permanently holding the vessel open and improving the flow of blood.
what are drug eluting stents?
they are stents coated with an agent that inhibits restenosis.
ex. cypher stent coated with abx called sirolimus(rapamycin) which is slowly released into the artery for 30days after implantation
List some factors associated with higher restenosis rates
-small luminal diameter
-longer more complex lesions
can stents be replaced?
- no, new stents can be added but the old stents are not removed.
medications for post op angiogplasty:
-with stent placement
-with or without stent placement
Angioplasty with stent placement: P2Y12 inhibitors for 12mo or longer
Angioplasty with or without stent: aspirin for life.