Cardiology handbook

Question 1

What is management of NSTEMI?

Answer 1

1. Admit CCU for high risk cases*.
2. Bed rest with continuous ECG monitoring
3. ECG stat and repeat at least daily for 3 days (more frequently in severe cases to look for evolution to MI).
4. Serial cardiac injury markers (CK-MB, troponin, myoglobin; depending on availability). Troponin stat (can repeat 3–12 hours later if 1st Troponin is normal)
5. CXR, CBP, R/LFT, lipid profile (within 24 hours), aPTT, INR as baseline for heparin Rx.
6. Allay anxiety - Explain nature of disease to patient.
7. Morphine IV when symptoms are not immediately relieved by
   nitrate e.g. Morphine 2–5 mg iv (monitor BP).
8. Correct any precipitating factors (anaemia, hypoxia,
   tachyarrhythmia).
9. Stool softener & supplemental oxygen for respiratory distress.
10. Consult cardiologist to consider GP IIb/IIIa antagonist, IABP, urgent coronary angiogram/revascularisation if refractory to medical therapy

Question 2

What is specific drug treatment for NSTEMI/unstable angina?

Answer 2

Anti thrombotic therapy:
aspirin
clopidogrel 300-600mg stat, then 75mg faily or ticagrelor 180mg stat, then 90mg BD
LMWH e.g. enoxaparin 1mg/kg sc q12h

Antiischemic therapy
Nitrates: Nitrophol, isosorbide dinitrate, isosorbide dinitrate
B blockers: reduce HR and BP
Metoprolol (betaloc) 25-100mg bd
Atenolol 50-100mg daily
CCB (when B blocker is contraindicated in the absence of clinically significant LV dysfunction): diltiazem, verapamil

Other therapies
Statin: given regardless of baseline LDLc
ACEI: within first 24 hours in the absence of hypotension or contraindications. ARB if intolerant to ACEI

Question 3

What are high risk features in NSTEMI/untable angina that may warrant early PCI?

Answer 3

 Ongoing or recurrent rest pain
 Hypotension & APO
 Ventricular arrhythmia
 ST segment changes  0.1 mV; new bundle branch block  Elevated Troponin > 0.1 mg/mL
 High Risk Score (TIMI, GRACE)

Question 4

What are absolute contraindications and relative contraindications for fibrinolytic therapy?

Answer 4

Absolute:
* Previous haemorrhagic stroke at any time, other strokes or CVA within 3 months; except acute ischaemic stroke within 4.5 hours
* Known malignant intracranial neoplasm (primary or metastatic)
* Known structural cerebrovascular lesion (e.g. AV malformation)
* Active bleeding or bleeding diathesis (does not include menses)
* Suspected aortic dissection
* Significant closed head or facial trauma within 3 months Intracranial or intraspinal surgery within 2 months Severe uncontrolled hypertension (unresponsive to emergency therapy)
* For Streptokinase, prior treatment within previous 6 months

Relative:
* Severe uncontrolled hypertension on presentation (blood pressure > 180/110 mmHg) †
* History of chronic, severe, poorly controlled hypertension
* History of prior ischaemic stroke > 3 months or known intracerebral pathology not covered in absolute contraindications
* Traumatic or prolonged (>10min) CPR
* Oral anticoagulant therapy
* Major surgery < 3 weeks
* Noncompressible vascular punctures
* Recent (within 2–4 weeks) internal bleeding Pregnancy
* Active peptic ulcer

Question 5

What is BLS (basic life support) for CPR?

Answer 5

Determine unresponsiveness
Call for help, defibrillator
Wear PPE
Check for breating and pulse (no more than 10 secs): no normal breathing, has pulse –> provide rescue breathing; 1 breath every 5-6 secs.
No breathing or gasping, no pulse –> start CPR
C: circulation with CPR. Chest compressions at a rate of 100/min to 120/min. At least 2 inches (5cm), avoid excessive depths. CPR 30 compression and 2 breaths
A: Airway: clear airway obstruction –> head tilt chin lift or jaw thrust, insert oropharyngeal airway
B: breathing: bag mask device ventilation with supplementary oxygen, tight seal between face and mask. Cycles of 30 compressions and 2 breaths before advanced airway
D: when defibrillator arrives: check rhythm. If shockable rhythm (VF/ pulseless VT) -> given 1 shock (biphasic 200J, or monophasic 360J), resume CPR immediately until nexdt rhythm check or patient moves
If non shockable rhythm –> continue CPR

Question 6

What is the ACLS management?

Answer 6

A: place arway devices; intubation if skilled (if not conitneu with bag mask ventilation)
B: confirm and secure airway: maintain ventilation. Confirm corect placement of endotracheal tube by PE (5 point auscultation) and confirmation device
Continous waveform capnography is recommended in addition to physical examination
Once advanced airway in place, give 1 breath every 6 secs with continous chetd compression
C: intravenous access; use monitor to identify rhythm
D: differential dx

Drugs used in resuscitation
Adrenaline 1mg (10ml of 1:10000 solution) q3-5min iv
Lignocaine 1mg/kg iv bolus, then 1-4mg/min infuison
Amiodarone In cardiac arrest due to pulseless VT or VF, 300mg iv bolus, further doses of 150mg iv bolus if required
MgSO4: 1-2g in 10ml D5 iv bolus in torsade de pointes

IV or intraosseous route of drug admin preferrred over endotracheal tube
Tracheal admin of resuscitation medications:
Lignocaine, epinephrine (adrenaline), atropine, narcan (LEAN)
Double dosage
Dilute in 10ml NS or water
Put catheter beyond tip of ET tube
Inject drug solution quickly down ET tube, followed by several quick insufflations

Question 7

What is the post resuscitation care with return of spontaneous circulation (ROSC)?

Answer 7

• Correct hypoxia with 100% oxygen to maintain oxygen saturation >94%
• Consider advanced airway and waveform capnography
• Do not hyperventilate
• Treat hypotension with volume expander or vasopressor
• Consider treatable causes
• Initiate targeted temperature management in comatose patients
• Treat seizure with anticonvulsants (diazepam or phenytoin)

Question 8

What is the management of VFib or pulseless ventricular tachycardia?

Answer 8

Question 9

What is the management of asystole/pulseless electrical activity (PEA)?
Causes (5Hs and 5Ts)

Answer 9

Question 10

What is the general management of tachycardia with a pulse?

Answer 10

Identify and treat underlying cause
Maintain patent airway; assist breathing
Oxygen (if hypoxemic)
Cardiac monitor to identify rhythm, monitor BP and oximetry
IV access
12 lead ECG

Question 11

What is the initial management for AFib/A flutter (irregular pulse)?
In WPW syndrpome, AF comp[licating acute illness, impaired cardiac function (EF <40%, CHF)?

Answer 11

1. Correct underlying cause: hypoxia, electrolyte disorders, sepsis
2. Control of ventricular rate
   Diltiazem 0.25mg/kg iv bolus over 2min, then 5-15mg/hr oral maintenance 120-360mg daily (ER)
   Verapamil 0.075-0.15mg/kg iv bolus over 2 min, may give additional 10mg after 30 min if no response, than 0.005mg/kg/min infusion. Risk of hypotension, check BP before 2nd dose
   Metoprolol: 2-5mg iv bolus over 2 min; up to 3 doses; oral maintenance 25-100mg BD
   Amiodarone: 300mg iv over 1 hour, then 10-50mg/hr over 24 hr; oral maintenance 100-200mg daily
   Digoxin: 0.25 mg iv with repeat dosing to a maximum of 1.5mg over 24hr; oral maintenance 0.125-0.25mg daily

WPW syndrome with preexcited AF, consider IV procainamide (all AVN blocking agents should be avoided)
AF complicating acute illness e.g. thyrotoxicosis, B blockers and verapamil may be more effective than digoxin
Impaired cardiac function (EF <40%, CHF), use digoxin or amiodarone

Question 12

What is the anticougulant, termination of arrhythmia, prevention of recurrence for AFib/A flutter (irregular pulse)?

Answer 12

Anticoagulation: unfractionated heparin with maintenance of aPTT 1.5-2 time control or low molecular weight heparin. Long term anticoagulation can be achieved with warfarin with maintenance of PT 2-3 times control (depends on CHA2DS2VASc score general condition.

Termination of arrhythmia: persistent AF, anticoagulate for 3 weeks before conversion and continue for 4 weeks after (delayed cardioversion approach)
Pharmacological conversion
Amiodarone 150mg over 10min then 1mg/min for 6hr than 0.5mg/min for 18 hours or orally 600-800mg daily in divided doses up to 10g, then 200mg daily as maintenance dose
Flecainide 200-300mg orally, preferably given BB or non DHP CCB >30 mins beforehand
Propafenone 450-600mg orally, preferable give BB or or DHP >30 mins beforehand
Procainamide: 15mg/kg iv loading at 20mg/min (max 1g), then 2-6mg/min iv maintenance

Synchronized DC cardioversion
Afib 120-200J and up
Aflutter 50-100J and up

Prevention of recurrence: class 1a, 1c, sotalol, amiodarone or dronedarone

Question 13

What is management of stable regular narrow complex tachycardia?

Answer 13

Question 13

What is the management of stable wide complex tachycarida (confirmed SVT, unknown type, confirmed VT)?

Answer 13

Question 14

What is the management of bradycardia with a pulse?

Answer 14

Question 15

What is hte Ix for Acute STEMI?

Answer 15

Serial ECG for 3 days
Repeat more frequently if only subtle changes on 1st ECG; or when patient complains of chest pain
Serial cardiac injury markers (CK-MB, troponin, myoglobiin, depending on availability)
CXR, CBP, R/LFT, lipid profile (within 24 hours)
aPTT, INR as baseline for thrombolytic Rx

Question 16

What is general management for acute STEMI?

Answer 16

• Arrange CCU bed
• Close monitoring: BP/P, I/O q1h, cardiac monitor
• Complete bed rest (for 12–24 hours if uncomplicated)
• O2 by nasal prongs if hypoxic with arterial oxygen saturation (SaO2) <90%; routine oxygen is not recommended if SaO2 >90%
• Allay anxiety by explanation/sedation (e.g. diazepam 2–5 mg po TDS)
• Stool softener
• Adequate analgesics prn e.g. morphine 2–5 mg iv (monitor BP & RR)

Question 17

What is the Rx protocol for STEMI?

Answer 17

2. e.g. Metoprolol 25 mg bd orally.
   Alternatively, metoprolol 5 mg iv slowly stat for 3 doses at 5 min intervals (Observe BP/P after each bolus, discontinue if pulse < 60/min or systolic BP < 100 mmHg).
3. Starting within the first 24 hrs, esp. for anterior infarction or clinical heart failure. Thereafter, prescribe for those with clinical heart failure or EF < 40%, (starting doses of ACEI: e.g. acertil 1 mg daily; ramipril 1.25 mg daily; lisinopril 2.5 mg daily)
4. Prescribe if persistent chest pain / heart failure / hypertension
   e.g. iv isosorbide dinitrate (Nitropohl/Isoket) 2–10 mg/h. (Titrate dosage until pain is relieved; monitor BP/P, watch out for hypotension, bradycardia or excessive tachycardia).
   C/I if sildenafil taken in past 24 hours

For primary PCI, give:
Clopidogrel loading 600 mg, 75 mg daily maintenance, OR
Prasugrel loading 60mg, 10 mg daily maintenance, OR
Ticagrelor loading 180 mg, 90 mg BD maintenance
For fibrinolytic therapy, give:
Clopidogrel loading 300 mg, 75 mg daily maintenance for age
≤75; and no loading dose for age >75
For age <75, Enoxaparin 30 mg iv bolus, followed in 15 min by
1mg/kg sc Q12H; for age 75, no loading dose, 0.75 mg/kg sc Q12H; give up to 8 days or until revascularization

Question 18

Treatment for symptomatic sinus bradycardia (complication of STEMI)?

Answer 18

Atropine 0.3-0.6mg iv bolus
Pacing if unresponsive to atropine

Question 19

Treatment of AV block (complication of STEMI)?
Ohter indications for temporar pacing?

Answer 19

1st degree and mobitz type 1 2nd degree block : conservative
Mobitz type II 2nd degree or 3rd degree: pacing (inferior MI, if narrow QRS ecape rhythm and adequate rate, conservative Rx under careful monitoring is an alternative)

Other indications for temporary pacing:
Bifascicular block + 1st degree AV block
Alternating BBB or RBBB + alternating LAFB/LPFB

Question 20

What is the treatment for tachyarrhythmia which are complications of STEMI (PSVT, AFib/Aflutter, wide complex tachycardia)?

Answer 20

PSVT: ATP 10-20 mg iv bolus. Verpamail 5-15mg iv slowly (C/I if BP low or on BB)
Aflutter/fib: digoxin 0.25mg iv/po stat, then 0.25 mg po q8H for 2 more doses as loading, maintenance 0.0625-0.25 mg daily. Diltiazem 10-15mg iv over 5-10 mins. Amiodarone 5mg/kg iv infusion over 60 mins as loading, maintenance 600-900mg infusion/24h

Stable sustained monomoprhic VT:
Amiodarone 150mg infused over 10 mins, repeat 150mg iv over 10 mins if needed, then 600-1200mg infusion over 24h
Lignocaine 50-100mg iv bolusm than 1-4mg/min infusion
Procainamide 20-30mg/min loading then 1-4mg/min infusion up to 12-17mg/kg
Synchronized cardioversion starting with 100J
Sustained polymorphic VT: unsynchronized cardioversion starting with 200J

Question 21

What is the management for pump falure (RV/LV dysfunction) complications of STEMI?

Answer 21

RV dysfunction: consider Swan Ganz catheter to monitor PCWP. If low or normal, volume expansion with colloids or crystalloids

LV dysfunction
Vasodilators (ACEI) if BP OK (PCWP monitoring)
Inotropic agents
Central vein. Titrate dose against BP/P and clinical state very 15 mins initially. - Startwithdopamine2.5microg/kg/minifSBP90mmHg, increase by increments of 0.5 g/kg/min
- Consider dobutamine 5–15 g/kg/min when high dose dopamine needed
IABP with a view for catheterization and revascularization

Question 22

What is aftercare for uncomplicated MI?

Answer 22

• Advise on risk factor modification and treatment
  (Smoking, HT, DM, hyperlipidaemia, exercise)
• Stress test (Pre-discharge or symptom limited stress 2–3 wks post MI) - Angiogram if +ve stress test or post-infarct angina or other
  high-risk clinical features
• Drugs for Secondary Prevention of MI
  BB : Metoprolol 25–100 mg bd, Aspirin : 81–325 mg daily
  ACEI: lisinopril (5-20mg daily)
  ARB is ACEI contraindicated and have HF or LVEF <40%

Question 23

What is the management of acute pulmonary edema?

Answer 23

Question 24

What is hypertensive emergency BP?
What is the general principles of management?

Answer 24

BP >180/120mmHg associated with evidence of new or worsening target organ damage e.g. hypertensive encephalopathy, acute MI, acute LV failure with pulmonary edema, unstable angina pectoris, dissecting aortic aneurysm, acute renal failure, eclampsia
Admit to ICU/CCU with continous BP monitor
With a compelling condition (i.e. aortic dissection, severe pre-eclampsia or pheochromocytoma crisis), reduce SBP to <140mmHg during 1st hour and to <120mmHg in aortic dissection
Without a compelling condition, reduce SBP by no more than 25% within the 1st hour, then if stable to 160/100mmHg within the next 2-6 hours; then cautiously to normal during the following 24-28 hours

Question 25

What are the IV medications for hypertensive emergency?

Answer 25

Labetolol 20mg iv over 2 mins. Repeat 40mg iv bolus if uncontrolled by 15 mins, then 0.5-2/mg/min infusion in D5 (max 300mg/d), followed by 100-400mg po BD
Na nitroprusside 0.25-10mg/kg/min iv infusion (50mg in 100ml D5 =500mg/ml, start with 10ml/hr and titrate to desired BP). Check BP every 2 mins still stable, then every 30 mins. Protect from light by wrapping
Hydralazine 5-10mg slow iv over 20 mins, repeat q30 mins or iv infusion at 200-300mg/min and titrate, then 10-100mg po 4x a day (avoid in AMI, dissecting aneurysm)
Phentolamine 5-10mg iv bolus, repeat 10-20 mins PRN (for catecholamine crisis)

Question 26

When is aortic dissection suspected?
What is done to make dx?
What is the management?

Answer 26

Suspect in patients with chest, back or abd pain and presence of unequal pulses (may be absent) or acute AR
Dx: CXR, ECG, cardiac enzymes
Transthoracic (not sensitive) + tranesophageal echo
Urgent dynamic CT scan, MRA and rarely aortogram

Mx
1. NPO, complete bed rest, iv line
2. Oxygen to keep sO2 >90%
3. Book CCU or ICU for intensive monitoring of BP/P. Arterial line on the arm with higher BP
4. Look for life threatening complication: severe HT, cardiac tamponade, massive hemorrhage, severe AR, myocardial, CNS or renal ischemia
5. Medical management: stabilize the dissection, prevent rupture and minimize complication from dissection propogation. It should be initiated before results of confirmatory imaging studies.

Therapeutic goals: reduction of systolic BP to 100-120mmHg (mean 60-75mmHg) and target HR of 60-70/min
6. IV labetolol 10mg ivi over 2mins, followed by additional doses of 20-80mg every 10-15 mins (up to max total dose of 300mg)
Maintenance infusion: 2mg/min, and titrating up to 5-20 mg/min
IV sodium nitroprusside: starting dose 0.25mg/kg/min, increase every 2 mins by 10ugram/min, max dose 8mg/kg/min
Use in caution in patient with renal impairmentm limit infusion rate to <3mg.kg/min if eGFR <30ml/min/1.73m2.
Diltiazem and verapamil are acceptable alternatives when B blockers are contraindicated (COAD)
7. Contact CTS surgeon for all proximal dissection (Type A) and complicated distal dissection (type B) e.g. shock, renal artery involvement, haemoperitoenum, limbs or visceral ischemia, periaortic or mediastinal haematoma or haemoperitoneum, persistent or recurrent pain

Question 27

What are the investigations for pulmonary embolism and expected results?

Answer 27

• Clotting time, INR, aPTT, cardiac enzymes, ABG, D-dimer
• CXR (usually normal, pleural effusion, focal oligemia, peripheral wedge)
• ECG (sinus tachycardia, S1Q3T3, RBBB, RAD, P pulmonale)
• TTE +/- TEE; lower limb doppler
• CT pulmonary angiogram or spiral CT scan
• Ventilation perfusion scan

Question 28

What is treatment for pulmonary embolism?

Answer 28

1. Oxygen to keep sO2>90%
2. Analagsics e.g. morphine iv 2-5mg
3. Haemodynamically insignificant

UFH 5000 units iv bolus, then 500-1500 units/hr to keep aPTT 1.5-2.5 x control or enoxaparin 1mg/kg q12h
Start warfarin on day 2 to 3:5mg daily for 2 days, then 2 mg daily on 3rd day adjust dose to keep INR 2-3.
New oral anticoagulants are alternatives to warfarin
Dabigatran: >5 days of a parenteral anticoagulant, then start 150mg bd
Rivaroxaban: for initial therapy or transition from parenteral anticoagulant: 15mg bd for 21 days than 20mg daily
Apixaban: for initial therapy or transition from parenteral anticoagulant: 10mg bd for 7 days then 5mg bd

Haemodynamically significant (no C/I to thrombolytic)
* Book ICU/CCU
* r-tPA 100mg iv over 2 hours followed by heparin infusion 500-1500 units/hr to keep aPTT 1.5-2.5 control
* Consider surgical embolectomy or percutaneous catheter directed treatment if condition continues to deteriorate or contraindication to thrombolytic therapy

4. Consider IVC filter if PE occurred while on adequate anticoagulation or who have absolute contraindications to anticoagulation

Question 29

What are the complications of STEMI?

Answer 29

• Arrhythmia
  Symptomatic sinus bradycardia, AV block, tachyarrhythmia (PSVT, Aflutter/Fib, wide complex tachy (VT or aberrent conduction )
• Pump failure: RV/LV dysfunction
• Mechanical complications: VSD, mitral regurgitation (cardaic catheterization and repair if unstable (IABP for interim support)
• Pericarditis (Dressler syndrome): high dose aspirin, NSAID e.g. indomethacin 25-50mg TDS for 1-2 days. Others: colchicine, paracetamol

Question 30

Define cardiac tamponade
Causes
dx
SS

Answer 30

Pericardial effusion compressing one or more cardiac chambers and leading to haemodynamic compromise. In acute conditions, the pericardium cannot distend, and its pressure rises markedly with small volume changes

Common causes: neoplastic, pericarditis (infective/non infective), uremia, iatrogenic, traumatic, acute pericarditis treated with anticoagulants
Dx: clinical –> pericardial effusion associated with haemodynamic compromise

SS
Tachypnea, tachycardia, small pulse volume, pulsus paradoxus
Raised JVP with prominent x descend, Kussmauls sign
Absent apex impulse, faint heart sound, hypotension, clear chest

Question 31

What Ix and management for cardiac tamponade?

Answer 31

Ix
ECG
CXR
Echo: RA, RV or LA colalpse, distended IVC, exaggerated tricuspid flow increases and mitral flow decreases during inspiration

Management
Expand intravascular volume: D5 or NS or plasma, full rate if in sock
Positive pressure mechanical ventilation avoided because the positive thoracic pressure can further impair cardiac filling
pericardiocentesis with echo guidance: apical or subcostal approach, risk of damaging epicardial coronary artery or cardiac perforation
Open drainge under LA/GA: permit pericardial biopsy

Misdx of cardiac tamponade as congestive heart failure with diuretics/ACEI or vasodilators can be fatal

Patients with malignant pericardial effusion resulting in cardiac tamponade stabilized by urgent pericardial drainage –> consult oncologist to determine benefit from surgical pericardiectomy (pericardial window)

Question 32

What are the indications for antibiotic prophylaxis for infective endocarditis?

Answer 32

high risk category
* Patients with prosthetic valve, including transcatheter valve, or a prosthetic material used for cardiac valve repair
* Patients with previous infective endocarditis
* Congenital heart disease, repaired congenital heart disease

Antibiotic prophylaxis for dental procedure
Amoxicillin/ampicillin 2g PO or IV (single dose 30-60 mins before procedure)
Allergic to penicillin/ampicillin –> clindamycin (600mg PO or IV)

Antibiotic prophylaxis for infective endocarditis is not recommended for respiratory/GI/urogenital/skin and soft tissue procedures unless they are performed in the context of infection

Established infection with GI or genitourinary tract –> active agent against enterococci
Surgical procedures involving infected skin (oral abscesses) –> agent active against staphylococci and b-hemolytic streptococci

Question 33

What is the periop cardiovascular evaluation for non cardiac surgery?

Answer 33

Question 34

What is stepwise approach to preop cardiac assessment for patients with known or risk factors for coronary artery disease?

Answer 34

Question 35

What is the algorithm for antiplatelet management in patients with coronary stenting and non cardiac surgery

Answer 35

Question 36

What is perioperative management of hypertension, cardiomyopathy/HF, valvular heart disease and prosthetic valves in non cardiac surgeries?

Answer 36

• Hypertension: control preop reduces periop ischemia. Evaluate severity, chronicity of HT and exclude secondary HT
  Severe HT (DBP >110 or SBP >180): elective surgery (better control first), urgent surgery: rapid acting drug to control (B-blocker)
• Cardiomyopathy and heart failure: assess severity of systolic and diastolic dysfunction (affect peri op fluid management)
  HOCM avoid reduction of blood volume, decrease in systemic vascular resistance or decrease in venous capacitance, avoid catecholamines
• Valvular heart disease:
  AS: postpone elective non cardiac surgery (mortality risk around 10%) in severe and symptomatic AS. Need AVR or valvuloplasty
  AR: careful volume control and afterload reduction (vasodilators), avoid bradycardia
  MS: mild or mod –> ensure control of HR, severe –> consider PTMC or surgery
  MR: afterload reduction and diuretic to stabilize haemodynamics before high risk surgery
• Prosthetic valve: reduce INR to subtherapeutic range (e.g. INR <1.3), resume normal dose immediately following the procedure
  Assess risk and benefit of decreased anticoagulation vs periop heparin

Question 37

What is perioperative management of arrhythmia, permanent pacemaker, ICD or antitachycardia devices?

Answer 37

Arrhythmia
High grade AV blocking: pacing
Intravent conduction delays and no history of advanced heart block or symptoms: rarely progress to complete heart block
AF: if on warfarin, may discontinue for a few days, ive PCC or FFP if rapid reversal of drug is necessary
Vent arrhythmia
Simple or complex PVC or non sustsained VT: usually require no Rx except myocardial ischemia or moderately to severe LV dysfunction function
Sustained or symptomatic VT: suppressed preop with lignocaine, procainamide or amiodarone

Permanent pacemaker
* Determine underlying rhythm, interrogate device to etermine threshold, settings and batery status
* If pacemaker in rate responsive mode –> inactivated
* Programmed to AOO, VOO or DOO mode prevents unwanted inhibition of pacing
* Electrocautery avoided; keep as far away from pacemaker

ICD or antitachycardia devices
Programmed off immediately before surgery and on again post op to prevent unwanted discharge
Inappropriate therapy from ICD, suspend ICD function by placing a ring magnet on the device
VF/unstable VT: if no or ineffective therapy from ICD and external defib/cardioversion is required, paddles preferably >12cm from the device

Question 38

What is the periop B blocker therapy indications?

Answer 38

1. Beta blockers should be continued in patients undergoing surgery who have been on beta blockers chronically.
2. In patients with intermediate or high risk myocardial ischaemia noted in preoperative risk stratification tests, it may be reasonable to begin preoperative beta blockers.
3. In patients with 3 or more risk factors (e.g. DM, HF, coronary artery disease, renal insufficiency, CVA), it may be reasonable to begin beta blockers before surgery.
4. In patients in whom beta blocker therapy is initiated, it may be reasonable to begin the medication long enough in advance to assess safety and tolerability, preferably > one day before surgery