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pacemaker . indications
Sinus Node Dysfunction
Pacemaker is indicated only in symptomatic patient regardless of the duration of pause.
Advance AV Block
Pacemaker is indicated in advanced AV block (Mobitz II, 3rd AVB, or high-grade AVB) regardless of the symptoms.
Short notes from brady guideline...

ICD . indications
provided that meaningful survival greater than 1 year is expected.
Primary Prevention
for those with high risks for SCD.
Secondary Prevention
Post arrest NOT from reversible causes.
High risk for SCD
  • LVEF ≤35%, NYHA II-III
  • Post MI, LVEF ≤30%, NYHA I
  • Post MI, NSVT, LVEF ≤40%, +EPS
  • HCM: LV thickness ≥30mm, LVOT obstruction, syncope, LV aneurysm, LGE >15%, LVEF <50%
  • ARVD: RV or LVEF ≤35% or syncope
  • LQTS: symptoms despite beta-blocker
  • Brugada: syncope with spontaneous type I
  • Adult congenital heart disease: syncope, moderate ventricular dysfunction or hypertrophy, or +EPS
Reversible causes
  • Acute ischemia
  • Proarrhythmic medication effects
  • Electrolytes disturbances
  • AF with WPW
  • Idiopathic outflow tract VT
  • Commotio Cordis
CRT . indications
QRS duration
BBB type
NYHA class
Issues during device implantation
during device implantation
  • Warfarin: Continue without Bridging.
    4.5 times lower incidence of hematoma in warfarin arm vs heparin bridging arm.
  • NOACs
    (Apixaban, Rivaroxaban, and etc)
    either Continue or Interrupt.
    Hematoma rate 2.1%; no differences in either continue or interrupt strategy.
  • Significant hematoma
    increases risk of device-related infection by 7 times.
    during device implantation
  • Warfarin: continue without interruption.
    4.5 times lower incidence of hematoma in warfarin arm vs heparin briding arm.
  • NOACs
    (Dabigatran, Apixaban, Rivaroxaban, and etc)
    either continue or interrupt.
    Hematoma rate 2.1%; no differences in either continue or interrupt strategy.
  • Serious hematoma increases risk of of device-related infection by 7 times.
Morphine Derivatives
  • Analgesic
  • Fentanyl, Morphine
  • Antidote: Naloxone or Narcan
  • Amnestic, Sedative
  • Midazolam (Dormicum), Diazepam (Valium)
  • Antidote: Flumazenil
radiation safety
What are the 3 principles of "ALARA"?
Principles of Aseptic Technique in an Operating Room
  • A sterile barrier that has been compromised by punctures, tears or moisture has to be considered contaminated.
  • Once a package is opened, a 2.5 cm (1 inch) border around the edge is considered unsterile.
  • Tables draped as part of a sterile field are considered sterile only at the table level.
  • Anything out of your range of vision or below waist level is considered contaminated and unsterile.
  • A sterile object or field can become contaminated by lingering exposure to air.
  • If there are any questions or doubts about an object's sterility, the object should be considered unsterile.
ConditionsDFT (YES/NO)Class of recommendation
Subcutaneous ICDYESI
Initial left-pectoral, transvenous implantation with well-positioned RV lead and adequate sensing. NOIIa
Right-pectoral implantation or generator changeYESIIa
Contraindications to DFT
documented nonchronic cardiac thrombus, AF or atrial flutter without adequate systemic anticoagulation, critical aortic stenosis, unstable CAD, recent stroke or TIA, haemodynamic instability, or other known morbidities associated with poor outcomes.
Acute Complications
ComplicationsWhat is it?What to do?
Cardiac Tamponade Fluid/Blood in the pericardiac space compressing the heart causing low cardiac output. During device implantation, lead or wire perforation is the major suspect. Echocardiogram to confirm. Pericardiocentesis to release the fluid.
Pneumothorax Air leaks into the pleural space compressing the lung causing desaturation. CXR to confirm. Thoracocentesis to release the air.
Oversedation Desaturation from hypoventilation or hypotension from vasodilatation. Maintain airways, IV fluid, +/-antidote.
Device infection
  • Most common pathogens: Staphylococcus aureus and epidermidis (coagulase-negative)
  • Complete device and lead removal is recommended for all patients with definite CIED system infection or CIED pocket infection.
  • Percutaneous aspiration of the generator pocket should not be performed as part of the diagnostic evaluation of CIED infection
Other Cardiac Tests
Tilt Table Test
  • Tilt the table at 70degree angle for 30-40mins.
  • May use adjunctive agents (Isoproterenol or nitroglycerine) to improve sensitivity.
  • Positive test = inducible presyncope or syncope with hypotension with or without bradycardia.
  • Can be useful if diagnosis of vasovagal syncope is unclear (IIa).
  • Reasonable to be used to differentiate syncope vs. fall vs. convulsion vs. pseudosyncope (IIa).
Electrophysiological Study
  • Asymptomatic 2nd degree AV block + intra- or infra-hisian block found in EP study = IIa for pacemaker.
  • EP study for assessing risk of ventricular arrhythmia: IIa in
    ICM | DCM | Adult Congenital Heart Disease
  • Not useful in HCM, LQTS, SQTS, CPVT, Early repolarization syndrome, and those who are already indicated for ICD.
Questions and Answers
A 35-year-old man with tetralogy of Fallot, which was surgically repaired in childhood, presents for evaluation of palpitations. He is healthy and denies exercise intolerance. He is not on any medications. Which of the following findings is associated with an increased risk of ventricular arrhythmias in this patient?
  1. Body mass index < 19 kg/m2
  2. Arterial Oxygen saturation < 90%
  3. Severe tricuspid regurgitation on echocardiography.
  4. Right aortic arch noted on chest radiography.
  5. QRS duration of 210 ms on resting electrocardiogram.
show answer
Answer: e. QRS>180ms increases risks of VT/VF in tetralogy of Fallot (TOF)
  • Most common congenital cyanotic heart disease.
  • ICD for secondary prevetion in the absence of reversible causes and meaningful survival >1year.
  • Syncope + Moderate LV dysfunction: EP study or ICD.
  • EP study is useful in high risk cases.
    HIGH RISKS for SCA in TOF: prior palliative systemic to pulmonary shunts, unexplained syncope, frequent PVCs, atrial tachycardia, QRS duration ≥180 ms, decreased LVEF or diastolic dysfunction, dilated right ventricle, severe pulmonary regurgitation or stenosis, or elevated levels of BNP.
You are consulted to see a non-CRT responder. An exercise treadmill test was performed. The tracings are as shown. What would be the most likely cause of not responding to the CRT?
  1. Loss of LV capture.
  2. Loss of RV capture.
  3. Intrinsic conduction.
  4. Negative AV hysteresis.
show answer
Answer: c. During the exercise, as shown in the right-sided tracing, fusion between biventricular pacing and native QRS occurs. The positivity of QRS in V1 is clearly lost when compared with the resting ECG on the left sided.
Frontal QRS axis during different pacing configurations. Europace 2012
CLUE to LV/RV/BiV pacing
  • Use leads V1, I, aVL, and III.
  • Positive in V1, Q in I and aVL suggest left to right forces = LV pacing.
  • Positive in III suggests force from left lateral area = LV pacing.
A 76 year-old woman has shortness of breath 6 hours after undergoing a pacemaker. The pacemaker was done via cephalic route. On physical examination, her chest is clear, her BP is 80/50 mmHg, and the rhythm is AV paced at 70 bpm. Which of the following is the most appropriate management?
  1. Administer of furosemide.
  2. Administer of salbutamol.
  3. Echocardiogram.
  4. Chest X-ray.
  5. Intravenous fluid.
show answer
Answer: c.
Think of cardiac tamponade for hypotension and shortness of breath shortly after a device implantation. Pneumothorax is an unlikely complication for cephalic access. Heart failure, asthma exacerbation, or dehydration are possible but does not require an emergent diagnosis and treatment the same way cardiac tamponade does.
A patient undergoes a cardioversion six months after undergoing implantation of a dual chamber pacemaker (DDD 60/140). After the cardioversion, the ECG monitor shows ventricular pacing at 65 bpm with no evidence of either atrial pacing or tracking. Which one of the following is the most appropriate course of action?
  1. Obtaine a chest X-ray.
  2. Replace the generator.
  3. Reprogram the pacemaker.
  4. Place a temporary pacemaker.
  5. Place a magnet over the generator.
show answer
Answer: c.
EMI from cardioversion causes power-on-reset.
What are the clinical advantages of AV nodal ablation and SSIR pacing in the setting of Atrial Fibrillation with a Rapid Ventricular Response?
  1. Slow the atrial rate.
  2. Allow for AV synchrony.
  3. Provide controlled and regular ventricular rate.
  4. Prevent endless-loop tachycardia.
show answer
Answer: c.
AV nodal ablation has nothing to do with the atrial rate. AV synchrony cannot be acheived with atrial fibrillation. End-less loop tachycardia is not possible with AF.
What medication should not be discontinued post SVT ablation?
  1. Propranolol
  2. Verapamil
  3. Digoxin
  4. Atenolol
  5. Warfarin
show answer
Answer: e.
Except warfarin, the rest of the medications are rate-slowing drugs which could be discontinued after a successful ablatino. Warfarin is a blood thinner which is generally indicated for prevention of strok and thromboembolism. In this case, the indication is unknown; yet, discontinuation is not advised.
This tracing was recorded during a tilt table test of a 21 year-old man who has had frequent episodes of presyncope and syncope over the past 3 months. Which of the following is the most appropriate treatment for this patient?
  1. Beta blocker
  2. Florinef
  3. ICD
  4. Pacemaker
  5. Education, diet, exercise
show answer
Answer: e.
Tracing from tilt table test shows neurocardiogenic or vasovagal syncope. BP and HR slowly drop. There is a brief period of asystole which quickly recovers. The initial treatment of neurocardiogenic syncope is education and lifestyle modification to avoid possible triggers such as prolong standing or warm environments.
A 32-year-old woman is referred for evaluation of multiple syncopal events over the last 5 years. Her workup include a negative tilt table test, a normal ECG, echocardiogram, and normal holter monitor. She then received an implantable loop recorder. The following tracing was recorded.
Which of the following would be the next appropriate management?
  1. Increase salt and water intake to her diet.
  2. Start midodrine.
  3. Implant a pacemaker.
  4. Continue monitoring.
show answer
Answer: d.
Pause artifacts are as shown.
A 48 y/o woman with a non-ischemic cardiomyopathy and chronic class II systolic heart failure symptoms despite guideline directed medical therapy underwent implantation of a subcutaneous implantable cardioverter-defibrillator (ICD) for primary prevention of sudden death. She presented 3 months later for a routine ICD device interrogation. Her device setting and presenting rhythm are shown in the left-sided figure. Review of her stored electrograms (right-sided figure) showed an untreated episode several weeks earlier.
Which of the following is the next best step?
  1. Schedule follow-up for device interrogation in 3 months.
  2. Schedule the patient for a procedure to reposition the subcutaneous ICD lead.
  3. Change the sensing configuration to an another vector.
  4. Perform an exercise stress test.
show answer
Answer: d.
TWOS during exercise.
At presentation, the patient is in sinus rhythm. At the programmed sensing configuration, each QRS complex is sensed appropriately. Thus, changing the sensing vector empirically to another configuration would not be indicated.
The stored electrogram demonstrates clear evidence of a change in QRS morphology associated with T-wave oversensing in the initial portion of the tracing. The electrogram by the end of the tracing is sensed appropriately and resembles the electrogram obtained at the patient’s device interrogation on presentation. Since the device detected the rhythm as a ventricular arrhythmia, simply ignoring the observation would not be suggested. On the other hand, it is premature to consider repositioning the ICD lead. T wave oversensing is by FAR the most common cause of oversensing in the subcutaneous ICD and this is typically evaluated by ETT and changing the sensing vector.
The most likely explanation is that the patient develops a rate-related bundle branch block during which the current programmed sensing configuration cannot adequately distinguish between QRS complexes and T waves. Thus, an exercise stress test will be useful to optimize the sensing configuration using a template acquired during exercise when the rate related QRS morphology can be replicated.
A 28 y/o woman experienced a sudden syncopal episode while exercising. Her father had sudden cardiac death at age 38. Her ECG is shown. The most appropriate initial treatment is:
  1. ICD implantation.
  2. Start Nadolol.
  3. Implantation of ILR.
  4. EP study.
show answer
Answer: b.
ECG = Long QT. Beta blocker is the first line.
The ECG shows a markedly prolonged QT interval (about 580 ms corrected). Combined with a history of sudden syncope while exercising and family history of sudden cardiac death, long QT Syndrome Type 1 (LQT1) is the most likely diagnosis. Beta blocker therapy is a Class 1 recommendation in LQT1 patients with syncope. ICD therapy is reserved for patients who have recurrent symptoms on beta blockers or have survived cardiac arrest.
A 72-year-old patient was admitted for stroke. He had been implanted with a dual-chamber pacemaker 2 months ago for sinus node dysfunction. Interrogation of the pacemaker was normal and did not disclose any atrial arrhythmias that may have explained the neurological event. A chest X-ray was performed and shown above.
Where is the ventricular lead positioned?
  1. RV apex.
  2. RV with situs inversus.
  3. Left atrium.
  4. Coronary sinus tributary.
  5. Left ventricular apex.
show answer
Answer: e.
LV apex via foramen ovale.
An apical RV lead would be expected to be situated in a lower position than the one shown in PA view. The lateral chest X-ray shows the ventricular lead to be posterior, whereas an RV lead would be anteriorly located in a patient implanted with an apical RV lead. An endocardial left ventricular lead does not course at the border of the cardiac silhouette, contrary to a CS lead which is epicardial.
Which of the following findings is most likely shown on the X-ray obtained from a 66-year-old man with SSS who underwent a DDD pacemaker implantation 1 month ago.
  1. Dextrocardia.
  2. Image flipped from left to right.
  3. Mustard operation.
  4. Persistent left superior vena cava.
  5. Arterial implantation
show answer
Answer: d.
Left SVC drains through coronary sinus and into RA and RV.
Persistent Left Superior Vena Cava is the most common variation of the thoracic venous system. It is generally benign if found isolated.
An 82-year-old Caucasian male with ischemic cardiomyopathy, left ventricular ejection fraction (LVEF) 0.10, with impaired right ventricular function, patent left internal mammary artery (LIMA) to the left anterior descending artery (LAD), but multiple occluded saphenous venous grafts, status/post single lead ICD without history of shocks, intraventricular conduction delay on electrocardiogram (ECG), heart rate of 66 bpm off beta-blockers, progressive renal impairment, and three hospitalizations over the prior calendar year is re-hospitalized and placed on dobutamine for several days. His device is interrogated and noted to be nearing end-of-life (within 1-3 months). The patient and family express an interest in proceeding with less aggressive care.
At this juncture, which of the following is the best approach to management of the ICD?
  1. Selective inactivation of shock therapies while maintaining back-up ventricular pacing.
  2. Elective generator change.
  3. Upgrade to a CRT-D.
  4. Electrophysiological study to evaluate for placement of an atrial lead.
  5. Use of a beta-blocker with intrinsic sympathomimetic activity.
show answer
Answer: a.
End-of-life care
The decision to inactivate the shock function of a defibrillator needs to take into account patient preferences and overall prognosis, especially when heart failure symptoms have progressed despite optimal medical therapy. ACC/AHA guidelines suggest that a reasonable prognosis for survival of at least 1 year applies to de novo implants; the same applies to generator changes. Similarly, there are no randomized clinical trials that support CRT upgrades with this degree of heart failure, though case series have been published. There is no role for atrial pacing at this juncture; the patient clearly has diffuse conduction disease and the natural history will not be impacted. There are no data to support the use of any beta-blocker with intrinsic sympathomimetic activity for any stage of heart failure.
82 year-old man develops change in mental status and hypotension while he is being monitored in ICU for acute pneumonia. The rhythm strips show complete heart block with ventricular escape of 30bpm. Atropine 1 mg was given without significant changes in heart rate and BP. What would be the most appropriate next step?
  1. Atropine 1 mg
  2. Atropine 2 mg
  3. Dopamine IV drip
  4. Transvenous temporary pacing
show answer
Answer: c.
Although not first-line agents for treatment of symptomatic bradycardia, dopamine, epinephrine, and isoproterenol are alternatives when a bradyarrhythmia is unresponsive to or inappropriate for treatment with atropine, or as a temporizing measure while awaiting the availability of a pacemaker.
A 70 year-old woman undergoes AV node ablation and CRT implantation for chronic AF and poor LVEF. Which of the following is the most likely reason for setting the initial lower rate of the device to 90 bpm?
  1. To improve cardiac output.
  2. To regularize ventricular rate.
  3. To avoid ventricular tachycardia.
  4. To enhance biventricular pacing.
  5. To improve ventricular remodelling.
show answer
Answer: c.
Rapid V pacing to prevent torsades.
Sudden death secondary to torsades de pointes or ventricular fibrillation has been reported after AV junction ablation. This outcome is possibly related to increased dispersion of ventricular refractoriness produced by sudden heart rate slowing and ventricular pacing. After ablation, the ventricular pacing rate is usually set between 90 bpm and 100 bpm and then gradually tapered over several months.
A 59-year-old man is admitted to the hospital with acute anterior wall myocardial infarction. He undergoes an angioplasty and stent placement in the proximal LAD. His left ventricular ejection fraction at the time of angioplasty was 30% with a hypokinetic anterior wall. Prior to discharge, he is noted to have asymptomatic 7 beats of non-sustained ventricular tachycardia.
The next best step is:
  1. Implant a single chamber ICD before discharge.
  2. Perform an electrophysiological study before discharge.
  3. Schedule an ICD implantation in a month.
  4. Continue to monitor and reevaulate LVEF in a month.
show answer
Answer: d.
Asymptomatic NSVT within the first 40-day after MI does not warrant treatment other than standard post MI treatment.
A 79-year-old man without structural heart disease presents with the tracing as shown. Which of the following is the most appropriate mode of pacing?
  1. AAIR
  2. DDI
  3. VDD
  4. VVIR
show answer
Answer: c.
ECG = complete heart block. VDD or DDD are the appropriate pacing mode.
A 17-year-old boy presents with an episode of syncope. Physical examination shows systolic murmur. An echocardiogram shows hypertrophic cardiomyopathy with septal thickness of 30mm and left ventricular outflow tract gradient of 50mmHg.
The next best step is:
  1. Alcohol ablation of the septum.
  2. Electrophysiologic study.
  3. Implantation of an ICD.
  4. Implantation of a dual chamber pacemaker.
  5. 24-hour holter monitoring.
show answer
Answer: c.
High risk HCM --> ICD is indicated.
Which of the tissue planes shown is the appropriate level of insertion for implantation of a pacemaker in most patients?
  1. A
  2. B
  3. C
  4. D

show answer
Answer: c.
Subcutaneous pocket = below fat and above muscle layers.