Cardiac Diagnostics and Therapies 1 Flashcards
Echocardiography
- benefits
- 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
Transesophageal echo
- whats an advantage to this?
- indications
-gives a more detailed evaluation than echocardiography.
Indications:
-intracardiac thrombus
- 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
- holter monitor
- event monitor
- electrophysiology studies
Describe the Holter monitor? Describe the event monitor.
Holter:
- worn 24hrs
- patient records a diary of activities and sx
- ambulatory monitor
Event:
- worn for a month
- patient triggers the monitor to record during sx
- ambulatory monitor
Ambulatory cardiac monitors are useful to investigate the following…..
- palpitation
- to assess rate control or determine % atrial fibrillation
- syncope
- intermittent dizziness or light headedness that does not seem to be orthostatic
- suspected bradycardia
- evaluate for suspected or known arrhythmias
Electrophysiologic Studies
- 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
Indications:
- unexplained syncope
- survivors of sudden cardiac death that was not related to an ischemic event
- palpations preceeding syncope
Interventions for arrhythmias and systolic heart failure
- pacemaker
- defibrillators
- Therapy for advanced heart failure
- -Bi-ventricular pacing
- -LVAD
Pacemaker
-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?
PACEMAKERS!!!!
What are the different types of pacemakers?
- External pacemaker
- Permenent Pacemakers
- Biventricular Pacemaker
- ICD
When are external pacemakers used?
- in emergencies as a bridge therapy.
- used for initial stabilization of hemodynamically sifnificant bradycardia
Permanent Pacemaker
- how does this work?
- types
-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.
Types:
- 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
- tachy-brady syndrome
- 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?
Pacemaker Syndrome:
- 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.
ICD therapy
- functions
- how does this differ from a pacemaker?
- indications
- 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.”
- indications:
- 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 (LVAD) -indications -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
-types?
- 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.
