cardiac dx and invasive procedures Flashcards
1
Q
pros of an echo
A
- rapid
- accurate
- readily available
- portable
- noninvasive
2
Q
Types of transthoracic echo?
A
- M mode
- 2D cardiac images
- color flow doppler: check flow through heart, across valves
3
Q
What information does a echo provide us with?
A
- cardiac structure: chamber size, muscle thickness
- fxn: ejection fraction, wall motion (wall not moving - past MI)
- aortic root size (AAA)
- valve structure and fxn
- intracardiac blood flow (shunts and pressures)
- portable (mini) used in ED for screening for tamponade, effusion
4
Q
A transesophageal echo can provide us with a detailed eval of what?
A
- intracardiac thrombus: prior to direct current cardioversion (looking for clots)
- valve function: for further eval beyond TTE, for use in operating room during valve replacement
- endocarditis: looking for vegetations
5
Q
What do we use to detect abnormal rhythms?
A
- holter monitor
- event monitor
- electrophysiology studies (EPS)
6
Q
Difference b/t holter and event monitor?
A
holter: wear for 24 hrs
- pt records diary of activities and sxs
- many times asx during this time period
event: worn for a month, pt trigger the monitor to record during ss
- newer devices will detect sig arrhythmias, without pt triggering device to record
(king of hearts monitor)
7
Q
Why are these ambulatory cardiac monitors useful?
A
investigate:
- palpitations
- assess rate control or determine percent of a fibb
- syncope
- intermittent dizziness or lightheadedness that doesn’t seem to be orthostatic
- suspected bradycardia (SOB or fatigue)
- eval for suspected or known arrhythmias
8
Q
What is an EPS?
A
- use multipolar electrode catheters placed in venous and or arterial circulation and advanced to various positions in the heart
- records an internal EKG
- defines conduction system disease
- attempts to induce arrhythmias (SVT and VT)
- measure response to pharm and or pacing device intervention
9
Q
What are the indications for EPS?
A
- unexplained syncope
- survivors of sudden cardiac death that wasn’t related to ischemic event
- palpitations preceding syncope
- poorly tolerated episodes of SVT
- many others - related to uncovering or tx arrhythmias
10
Q
What are the devices used for intervention of arrythmias and systolic heart failure?
A
- pacemakers
- defibrillators
- therapy for advanced heart failure:
bi-ventricular pacing
LVAD
11
Q
What is the function of pacemakers?
A
- provides electrical stimuli to cause cardiac contraction when intrinsic cardiac activity is inappropriately slow or absent
- only tx for bradyarrhythmias
12
Q
Different type of pacemakers?
A
- external pacemaker (transcutaneous pacemaker - used in acute situations)
- permanent pacemaker
- biventricular pacemaker
- ICD
13
Q
Indications for external pacemakers?
A
- used in emergencies as a bridge to therapy
- TCP recommended for initial stabilization of hemodynamically sig bradycardia
- place 2 pacing pads on pts chest, either in anterior/lateral position or anterior/posterior position
- short term until transvenous pacing or other therapies can be applied
14
Q
Process of perm placemaker placement?
A
- involves placement of 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 the pacemaker generator
- single lead - paces in ventricle
- dual chamber - can pace in atrium or ventricle
- generator is placed below the subq fat of the chest wall
15
Q
Indications for a pacemaker?
A
- sick sinus syndrome
- sx sinus bradycardia
- tachy-brady syndrome
- Afib with slow ventricular response
- 3rd degree heart block
- chronotropic incompetence: inability to increase heart rate to match exercise
16
Q
Functions of perm pacemakers?
A
- sensing (listening to heart’s native electrical rhythm)
- pacing - the device will stim the venticles of the heart with a set amt of energy, measured in joules at whatever heart rate the device is set at
- most common primary care and pt concern: pt comes in with HR of 55 when pacer is set at 60, don’t think that pacemaker is working adequately.
17
Q
What will you see on an EKG of a pt with pacemaker?
A
- pacemaker spike before QRS
- no P wave - if pacing in ventricle
18
Q
complications of pacemakers?
A
- pacemaker syndrome:
pt feels worse after pacemaker placement - pt with progressive worsening of CHF sxs
- due to loss of atrioventricular synchrony, pathway now reversed and ventricular origin of beat
19
Q
What is biventricular pacing reserved for?
A
- advanced heart failure
- biventricular pacing devices have added 3rd lead that is designed to conduct signals directly in the left ventricle
- combo of all 3 leads creates a synchronized pumping of ventricles
- gets rid of asynchrony b/t ventricles
- may increase EF
20
Q
What is ICD therapy?
A
- consists of pacing, cardioversion, and defibrillation therapies to tx brady and tachy arrythmias
- external programmer is used to monitor and access the device parameters and therapies in each pt
21
Q
Indications for ICD?
A
- used in cases where there wasa previous cardiac arrest
- pts with undetermined origin or cont VT or VF despite medical interventions
- cardiomyopathy: EF less than 35%
22
Q
Fxn of ICD?
A
- prevent sudden cardiac death: most commonly in pts with cardiomyopathy
- performs cardioversion/defibrillation: if ventricular rate exceeds programmed cut off rate
- ATP (antittachycardia pacing): overdrive pacing in an attempt to terminate ventricular tachycardias
- all have pacemaker fxn
23
Q
Lifepsan and placement of pacemakers and ICD?
A
- placed subq or submuscularly
- connected to leads
- battery: lithium iodide
life span: 5 to 10 years
output voltage decreases gradually: makes sudden battery failure unlikely
24
Q
In an emergency - can you still use external defibrillator with a pacemaker or ICD?
A
- yes
- sternal paddles should be placed a safe distance (10 cm) from pulse generator
- in case of MI: may require temporary transcutaneous pacing
25
What is an LVAD used for?
- severe systolic heart failure
- may serve as a bridge to transplant
- may be destination therapy
- pump of LVAD takes over work of left ventricle
- implantable tubes that connect to an external battery pack
26
PCIs?
- angioplasty (ballooning open the artery)
| - intracoronary stent placement: bare metal or drug coated
27
What is a balloon angioplasty?
- balloon catheter passed through guiding catheter to area near narrowing. A guide wire inside the balloon cath is then advanced through the artery until the tip is beyond the narrowing
- angiplasty catheter is moved over guide wire until the balloon is within the narrowed segment
- balloon is inflated, compressing plaque against artery wall
- once plaque has been compressed and the artery has been sufficiently opened the balloon cath will be deflated and removed
- high restenosis rate (30-40%) in first 6 months
- success rate: 90% of lesions attempted (includes repeat procedures)
28
Process of intracoronary stent placement?
- introduced into blood vessel on balloon cath and advanced into blocked area of artery
- balloon is then inflated and causes the stent to expand until it fits the inner wall of the vessel, conforming to contours as needed
- balloon is then deflated and drawn back
- the stent stays in place permanently, holding vessel open and improving flow of blood
- before stent implantation: the blocked artery usually is tx and dilated with one or more angioplasty balloons. A stent tightly mounted on special angioplasty balloon is then guided to site of blockage, it is inflated to stretch open stent and implant in walls of blocked artery
- balloon is deflated and removed and stent remains perm in place to hold artery open
- stents vary in size, the smaller the blood vessell the greater risk of restenosis
29
Drug eluting stents?
- coated with agent that inhibits restenosis
- cypher stent is coated with abx called sirolimus, which is slowly released into artery for about 30 days after implantation
- sirolimus is cytostatic drug, which means it inhibits cell growth and division, and T cell activation and proliferation. T cells initiate an inflammatory response that commonly follows implantation and inflammation can lead to restenosis
30
uncoated vs coated stents?
- with uncoated stents: restenosis occurs in 15-25% of pts
- restenosis rate in pts who receive drug eluting stent is lower than uncoated stents (less than 10%)
- these pts require fewer repeat procedures (add angiplasty, bypass surgery) and have lower risk for heart attack
31
What factors are associated with high restenosis rate?
- diabetics
- smoking
- small luminar diameter (smaller vessel)
- longer more complex lesions
- repeat procedures
32
Are stents replaced?
- no, new stents may be added but old stents can't be removed, endothelium lining grew around stent
- additional cardiac stents may be needed if new blockages occur in other parts of the artery
33
Meds after angioplasty/stent placement?
- angioplasty with or without stent placement:
aspirin for life (sig inflammatory reaction to angioplasty)
- angioplasty with stent placement: P2Y12 inhibitor for 12 months or longer in some cases
34
Complications of angioplasty/stent placement?
- restenosis (can happen in a couple of hours)
- arrythmias
- bleeding at insertion site
- Heart attack, stroke
- infection at insertion site
- kidney failure (from IV contrast)
- ruptured artery (dissection)
35
What is a CABG?
- procedure to bypass a blocekd section of a coronary artery and deliver O2 to the heart
- best artery to use is the LIMA
36
Who are CABG candidates?
- failed medical therapy for angina
- not good candidates for balloon angioplasty and stent placement
- pts with mult coronary lesions as is often seen in pts with diabetes
- left main stenosis - (left main stent - if pt isn't candidate for surgery)
- pts with sig narrowing of all 3 major arteries especially those with systolic dysfunction
37
CABG risks and complications?
- during and shortly after CABG surgery, heart attacks occur in 5-10% of pts and are main cause of death
- about 5% of pts require exploration because of bleeding, this second surgery increases risk of chest infection and lung complications
- stroke occurs in 1-2%
- mortality and complications increase with age (older than 70), poor heart muscle function, disease obstructing the left main, diabetes, chronic lung disease, and chronic kidney failure
- post op afib is common (myocardium irritation - leadd to arrhythmias)
38
Valve replacement or repair?
- aortic valve and mitral valve most commonly replaced valves
- pulm and tricuspid valve replacements are fairly uncommon
- most common valve surgical procedure is aortic valve replacement for aortic stenosis but also done for mitral stenosis, mitral regurg, and endocarditis
39
Surgical options for valve replacement?
- mechanical valve: long lasting valve made of durable materials, lifelong anticoagulation (lasts over 20 years)
- tissue valve (animal donor tissue) aka bioprosthetic: short term anticoagulation
- ross procedure: borrowing healtyh valve and moving it into position of damaged valve aortic valve
- TAVI/TAVR procedure ( transcatheter aortic valve replacement for not good surgical candidates)
40
Valve repairment?
- some valves can be repaired instead of replaced depending on disease process
- mitral, tricuspid and pulmonic
- aortic not usually repaired but may opt to do balloon vavuloplasty for palliation of sxs: short term results, and decrease risk of stroke
