Week 15 Handout Flipped Classrooms: Pacemakers and ICDs Flashcards
(76 cards)
1
Q
What is the purpose of pacemakers?
A
To regulate slow heartbeats by delivering electrical pulses to stimulate the heart.
2
Q
What are the indications for pacemakers?
A
SA node dysfunction, heart blocks, chronic bifascicular block, long QT syndrome, hypertrophic obstructive cardiomyopathy, dilated cardiomyopathy, post-acute MI, carotid sinus syndrome.
3
Q
What is the purpose of ICDs?
A
To detect and treat life-threatening ventricular arrhythmias with electrical shocks to restore normal rhythm.
4
Q
What are the indications for ICDs?
A
Supraventricular dysrhythmias, ventricular tachycardia/fibrillation, low Left Ventricular Ejection Fraction <30%, congestive heart failure, awaiting heart transplant, long QT syndrome, Brugada syndrome.
5
Q
What does the first character in pacemaker codes represent?
A
Chamber where the pacing electrode is placed.
6
Q
What does the second character in pacemaker codes represent?
A
Chamber where the sensing electrode is placed.
7
Q
What does the third character in pacemaker codes represent?
A
Pacemaker’s response to detection of a spontaneous cardiac depolarization & its effect on subsequent pacing.
8
Q
What does the fifth character in pacemaker codes represent?
A
Multisite pacing.
9
Q
What is a leadless pacemaker?
A
Implanted directly into the RV to manage slow heart rate.
10
Q
What does the first character in ICD codes represent?
A
Chamber shocked.
11
Q
What does the second character in ICD codes represent?
A
Chamber for anti-tachycardia pacing.
12
Q
What does the third character in ICD codes represent?
A
Detection method.
13
Q
What does the fourth character in ICD codes represent?
A
Backup pacing chamber.
14
Q
What is an S-ICD?
A
Subcutaneous ICD that delivers high energy defib shocks externally without intracardiac leads.
15
Q
What should be assessed in preoperative assessment for dysrhythmias?
A
Type of dysrhythmia and treatment history.
16
Q
What considerations are there for patients with SVT?
A
Meds may be withheld to make arrhythmia inducible.
17
Q
What considerations are there for patients with VT?
A
Consider older patients, reduced EF 10-35%, poor LV function, and high sensitivity to myocardial depressants/anesthesia.
18
Q
What is typical for patients with WPW?
A
Usually young & otherwise healthy.
19
Q
What is typical for patients with CHF?
A
Usually very low EFs & failed conventional treatment.
20
Q
What should be reviewed in health history?
A
CAD, HTN, valvular disease, diabetes, mitral insufficiency, and pulmonary diseases secondary to smoking history.
21
Q
What may CHF and poor ventricular function indicate?
A
Renal dysfunction.
22
Q
What should be done with cardiac medications before surgery?
A
Continue most cardiac medications up to surgery.
23
Q
What should be monitored for drug interactions?
A
Antiarrhythmics, diuretics, digoxin.
24
Q
What is evaluated in a preoperative ECG?
A
Rate, rhythm, and ischemia.
25
What does an echocardiogram assess?
Ejection fraction (EF) and wall motion.
26
What is the purpose of angiography in preoperative testing?
To evaluate ventricular function, rule out CAD, or LV aneurysm.
27
What lab tests are important for potassium levels?
Hypokalemia (↓ K+) can lead to loss of capture; Hyperkalemia (↑ K+) can cause ventricular tachycardia.
28
What additional lab tests are included in preoperative testing?
Digoxin and other drug levels, CBC (Hgb & Hct), coagulation panel (PT, PTT, Plt).
29
What imaging tests may be performed for pulmonary disease?
Chest x-ray or pulmonary function tests (PFTs).
30
What renal function tests are important preoperatively?
BUN and creatinine; electrolyte imbalances can cause cardiac irritability.
31
Where is the implantation procedure typically performed?
In the cath lab or hybrid OR.
32
What position should the patient be in during the procedure?
Supine.
33
What gauge IV access is recommended?
16–18 gauge.
34
What fluids are administered during the procedure?
Normal saline (NS) or lactated Ringer's (LR) at 4–8 mL/kg/hr.
35
What antibiotic is given before incision?
Cefazolin 1 g IV.
36
What is the typical duration of the implantation procedure?
1–2 hours with minimal blood loss (5-20 mL).
37
What monitoring is required during the procedure?
Standard monitors plus arterial line for ICD testing (± CVP or PA line for CHF patients).
38
Where is the incision typically made?
Left upper chest with horizontal (below clavicle) or oblique (deltopectoral groove).
39
What type of pocket is created for the device?
Subcutaneous (standard); subpectoral/submuscular is also an option.
40
What is the preferred venous access site?
Subclavian; cephalic or axillary are possible alternatives.
41
What leads are placed during the procedure?
Atrial and/or ventricular leads, depending on the device and patient.
42
What is tested during the lead placement?
Sensing & pacing threshold, depolarization amplitudes, & lead resistance.
43
What is required for ICD testing?
Deeper anesthesia to induce ventricular fibrillation (VF) and verify shock termination.
44
How is closure performed after lead placement?
The generator is placed near the incision for future removal, and leads are positioned underneath to prevent erosion.
45
What is the anesthetic plan for high-risk patients?
General anesthesia (LMA or ETT) is preferred for high-risk patients such as the elderly and those with CHF.
46
What are common induction agents?
Common induction agents include Midazolam 1–2 mg ± fentanyl 25–50 mcg and Propofol infusion 25–75 mcg/kg/min.
47
When should muscle relaxants be used during induction?
Muscle relaxants should only be used if intubation is needed.
48
What is the brief GA protocol for device testing?
Use mask ventilation and administer Propofol 1 mg/kg or Etomidate 0.1 mg/kg for stable induction.
49
What preparations should be made for induced VF/VT?
Use 100% oxygen, have lidocaine or amiodarone ready, and wait ≥5 minutes between shocks if the first shock fails.
50
What should be avoided in patients with CHF during maintenance?
Avoid fluid overload, especially in CHF.
51
What should be considered if LV function drops?
Consider inotropes if LV function drops.
52
When should extubation be delayed?
Delay extubation if multiple shocks are given, ST changes are present, or inotropic support is ongoing.
53
What complications should be monitored for postoperatively?
Monitor for dysrhythmia recurrence, lead dislodgement, pneumothorax/hemothorax, cardiac effusion/tamponade, and acute atrial fibrillation.
54
What postoperative tests are recommended?
Recommended tests include ECG, CXR, and electrolytes.
55
What is the usual pain management postoperatively?
Pain is usually mild; oral analgesics suffice.
56
What education should be provided to patients postoperatively?
Educate patients to sling the arm to avoid lead strain and to avoid lifting/pulling or raising the arm above the shoulder for weeks.
57
What are the electrocautery safety measures?
Place the ground pad away from the pulse generator, use bipolar or short monopolar bursts, and avoid cautery above the umbilicus.
58
What happens when a magnet is placed over an ICD or pacemaker?
A magnet over an ICD disables shocks, while over a pacemaker it causes asynchronous pacing.
59
What should be prepared for device malfunction?
Have emergency defib pads, interrogator, and manufacturer contact info in the room.
60
What are common drug interactions with Midazolam?
Midazolam combined with CCBs (verapamil/diltiazem) can lead to deep and prolonged sedation.
61
What is the interaction of Etomidate with Verapamil?
Etomidate combined with Verapamil increases apnea risk and respiratory depression.
62
What is the effect of Propofol when combined with CCBs?
Propofol combined with CCBs can lead to decreased blood pressure.
63
What is the interaction of opioids with Amiodarone or CCBs?
Opioids combined with Amiodarone/CCBs can lead to decreased blood pressure and heart rate.
64
What is the effect of NMBAs with other medications?
NMBAs combined with antiarrhythmics, beta blockers, calcium channel blockers, or diuretics can alter blockade duration.
65
What is the risk of inhaled agents with Amiodarone?
Inhaled agents combined with Amiodarone or QTc prolonging agents can enhance myocardial depression and conduction defects.
66
What is the role of pacemakers and ICDs?
Pacemakers treat bradyarrhythmia, while ICDs prevent sudden death from ventricular arrhythmias.
67
What does proper preoperative evaluation include?
Proper preoperative evaluation includes cardiac history, ECG, electrolytes, and medication review.
68
What does intraoperative care encompass?
Intraoperative care includes MAC sedation or GA, device testing management, and hemodynamic stability.
69
What is the focus of postoperative monitoring?
Postoperative monitoring focuses on lead stability, bleeding, and arrhythmia prevention.
70
What must anesthesia providers be prepared with?
Anesthesia providers must be prepared with emergency medications, defibrillation equipment, and manufacturer support resources.
71
Student Question: For a pacemaker (PM) , what does the third letter in the Heart Rhythm Society (HRS) code identify?
A. The chamber where the sensing electrode is placed
B. Rate modulation
C. The chamber where the pacing electrode is placed
D. The PM’s response to the detection of spontaneous depolarization
Answer: D) The PM’s response to the detection of spontaneous depolarization
Rational: The third letter of the code identifies the PM’s response to the detection of a spontaneous cardiac depolarization and its effect on subsequent pacing stimuli. The device will either inhibit or trigger a pacing stimulus. An “I” (inhibit) mean the PM response is withheld when intrinsic sensed activity is faster than the programmed lower rate limit. A “T” (trigger) in a single chamber mode, mean the PM will deliver a scheduled output pulse in response to sensed intrinsic activity. A “D” means the PM will either inhibit or trigger in response to sensed intrinsic activity. An “O” means then there is no sensing, and the PM will asynchronously provide pacing.
72
Student Question: Which of the following best describes the effect of placing a magnet over an ICD (which is programmed to recognize a magnet) during a procedure?
A. It switches the ICD to asynchronous pacing
B. It disables the ICD’s shock function
C. It increases the detection threshold for arrhythmias
D. It resets the device’s programming
Answer: B) It disables the ICD’s shock function
Rational: ICDs can be programmed to recognize a magnet, which will disable shock therapy, although not all devices are programmed to do so. The magnet placed on an ICD will not initiate asynchronous pacing.
73
Student Question: In cases where the programmed shock fails during defibrillation testing, what is recommended between repeated VF inductions?
A. Immediate intubation without delay
B. Switching to a different anesthetic
C. A minimum 5-minute interval to allow for hemodynamic recovery
D. Administration of an antiarrythmic drug
Answer: C) A minimum 5-minute interval to allow for hemodynamic recovery
Rational: During testing of defibrillation efficacy, VF is induced once or twice, and sometimes more frequently. In the event of failed defibrillation by the programmed first shock, a somewhat prolonged VF may occur. In the case of repeated DFT testing, it is customary to give at least 5-min intervals between VF inductions to allow for sufficient hemodynamic recovery.
74
Student Question: Which of the following descriptions is true regarding ICD/pacemaker implantation?
A, The procedure is relatively short (1-2hrs), EBL is minimal, and patients generally requires minimal sedation for the transcutaneous approach
B. The procedure is relatively short (1-2hrs), external defibrillation does not need to be readily available, and fentanyl 2-50mcg/kg should be given for induction
C. The procedure is long (4-5hrs), EBL is high, and patients must be under deep/general anesthesia
D. The procedure is long (4-5hrs), monitoring for electrolyte abnormalities preop is optional, and CVP or PA catheter placement is required
Answer: A) The procedure is relatively short (1-2hrs), EBL is minimal, and patients generally requires minimal sedation for the transcutaneous approach
Rational: In the transvenous approach, the insertion of leads and pulse generator requires minimal anesthesia. Exact type of induction depends on the patient's medical condition. Sedation can be provided with small doses of midazolam (1–2 mg) and fentanyl (25–50 mcg) titrated to effect or alternatively a propofol infusion (25– 75 mcg/kg/min) can be used. The procedure is typically 1-2 hours and estimated blood loss is minimal (5-20mLs). External defibrillation should always be available because verification of correct lead placement and testing the device's capability to restore NSR involves the induction of ventricular fibrillation or tachycardia.
75
Student Question: Following ICD/pacemaker implantation, what type of pain management is typically required postoperatively?
A. High dose IV pain medications because postop pain is typically severe
B. No pain medication is typically needed because patients receive regional anesthesia preoperatively
C. Oral analgesics typically sufficient for pain management
D. Fentanyl PCA 0.5 to 1.5 mcg/kg/hour
Answer: C) Oral analgesics typically sufficient for pain management
Rational: Postoperatively, pain is usually managed with oral analgesics. The typical pain level following a transvenous approach is 2-3. Oral analgesics are sufficient to manage this level of pain.
76
Student Question: For ICD/pacemaker implantation, general anesthesia is recommended for which patient populations? (SATA)
A. Elderly patients
B. Young athletes with
WPW syndrome
C. Patients in postacute phase of myocardial infarction
D. Patients with congestive heart failure (CHF)
Answer: A) Elderly patients & D) Patients with congestive heart failure (CHF)
Rational: General anesthesia is specifically recommended for elderly patients due to the risk of disorientation with sedation, and for CHF patients who may be orthopneic or expected to have a longer procedure.
Reference: Jaffe, R. A., Schmiesing, C. A., & Golianu, B. (2014). Anesthesiologist’s manual of surgical procedures (5th ed., p. 2265). Wolters Kluwer Health.
