cardiac dx and invasive procedures Flashcards
pros of an echo
- rapid
- accurate
- readily available
- portable
- noninvasive
Types of transthoracic echo?
- M mode
- 2D cardiac images
- color flow doppler: check flow through heart, across valves
What information does a echo provide us with?
- 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
A transesophageal echo can provide us with a detailed eval of what?
- 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
What do we use to detect abnormal rhythms?
- holter monitor
- event monitor
- electrophysiology studies (EPS)
Difference b/t holter and event monitor?
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)
Why are these ambulatory cardiac monitors useful?
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
What is an EPS?
- 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
What are the indications for EPS?
- 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
What are the devices used for intervention of arrythmias and systolic heart failure?
- pacemakers
- defibrillators
- therapy for advanced heart failure:
bi-ventricular pacing
LVAD
What is the function of pacemakers?
- provides electrical stimuli to cause cardiac contraction when intrinsic cardiac activity is inappropriately slow or absent
- only tx for bradyarrhythmias
Different type of pacemakers?
- external pacemaker (transcutaneous pacemaker - used in acute situations)
- permanent pacemaker
- biventricular pacemaker
- ICD
Indications for external pacemakers?
- 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
Process of perm placemaker placement?
- 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
Indications for a pacemaker?
- 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
Functions of perm pacemakers?
- 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.