Posts Tagged → Arrhythmia

LVAD

Brief H&P:

A 48 year-old male with a history of congestive heart failure s/p left ventricular assist device is brought in by EMS with low-flow alarms. According to prehospital report, the patient had otherwise been in his usual state of health and had been shocked by his ICD multiple times prior to their arrival. No vital signs could be obtained en route.

On arrival in the emergency department, the patient was awake and responding appropriately to questions. His MAP was 80mmHg, an audible whir was auscultated from his device and the skin surrounding the percutaneous exit site appeared normal.

ECG

ECG with Ventricular Fibrillation

POCUS

Ultrasound showing parasternal long axis view of fibrillating heart

The patient’s device was inactivated with a magnet to prevent further ineffectual shocks. An arterial line was placed for continuous blood pressure measurement. He was sedated and externally defibrillated with return to normal sinus rhythm prior to admission to the CCU.

An Algorithm for the Evaluation of Unstable LVAD1

Algorithm for the Evaluation of Unstable LVAD

Reference

Stenberg R, Shenvi C. Targeted evaluation of patients with left ventricular assist devices and shock or hypotension. Ann Emerg Med. 2020;76(1):34-41.

Atrial Fibrillation

A 64-year-old male with a history of hypertension and hyperlipidemia presents with palpitations. He reports intermittent symptoms over the past 3 days, associated with dyspnea on exertion, but no chest pain, dizziness or syncope. His vital signs are notable for tachycardia (HR 129bpm) without hypotension or hypoxia. An ECG shows atrial fibrillation with rapid ventricular response.

Evaluation and Management

While the patient’s tachyarrhythmia is not yet associated with hypotension or evidence of malperfusion, preparation is key and includes continuous telemetry and vital sign monitoring, establishment of intravenous access, and application of cardioversion pads 1.

The presence of atrial fibrillation is new and the rapid ventricular response (RVR) may be symptomatic of more serious and potentially reversible pathology. A thorough history and physical examination may elucidate a precipitant and should precede attempts at rate- or rhythm-control. RVR may be provoked by any of the processes that would otherwise induce a sinus tachycardia, including bleeding, infection, toxic/metabolic etiologies and endocrinopathies 2, 3

Candidacy for Cardioversion

In hemodynamically stable patients with new-onset atrial fibrillation, candidacy for cardioversion includes:4-6

  • Stable without ischemia, hypotension or acute CHF
  • Clear onset of <48 hours
  • Non-severe symptoms
  • Few prior episodes/treatments
  • Existing anti-coagulation with warfarin and therapeutic INR (at least 3 weeks)
  • Absence of high-risk features: rheumatic/valvular disease, severe left-ventricular dysfunction, prosthetic valves, or history of thromboembolism

Cardioversion may be pharmacologic (with procainamide, or amiodarone), or electrical (synchronized at 100-200J). Electrical cardioversion for acute atrial fibrillation is both more effective and results in shorter lengths-of-stay in the emergency department – though stable patients should participate in shared decision-making7. Another important consideration when cardioversion is pursued is the prevention of systemic embolization. While atrial fibrillation of duration less than 48-hours is rarely associated with systemic embolization, certain populations are at higher risk8. One retrospective study of 3143 patients with atrial fibrillation for less than 48-hours demonstrated an overall risk of 0.7% for thromboembolic events – though the rate was significantly higher in patients older than 60 years or with other comorbidities (heart failure, diabetes)9. The risk of embolic events should be weighed against the risk of bleeding.

CHA2DS2VASc10-12

C Congestive Heart Failure 1
H Hypertension 1
A2 Age >75 2
D Diabetes Mellitus 1
S2 Stroke, TIA, Thromboembolism 2
V Vascular disease 1
A Age >65 1
Sc Sex Category Female 1

 

  • 0: low risk (may not require anti-coagulation)
  • 1: low-moderate risk (consider anti-platelet or anti-coagulation)
  • ≥ 2: moderate-high risk (anti-coagulation recommended)

HAS-BLED13,14

H Uncontrolled hypertension 1
A Abnormal renal/liver function
Renal (renal replacement therapy, creatinine >2.3mg/dL) 1
Liver (cirrhosis, bilirubin >2x, AST/ALT >3x) 1
S Stroke 1
B Bleeding history/anemia 1
L Labile INR 1
E Elderly (>65) 1
D Drugs
Anti-platelet agent, NSAID 1
Alcohol (>8 drinks/week) 1

 

  • 0: low risk (0.6-1.13% annual risk of major bleeding)
  • 1-2: intermediate risk (1.02-3.2% annual risk of major bleeding)
  • ≥ 3: high risk (4.9-19.6% annual risk of major bleeding)

Pharmacologic Management

For patients who are not candidates for cardioversion, rate-control should be pursued. Options include AV nodal blocking agents such as calcium channel blockers and beta-blockers15. The most frequently studied agents of each category are metoprolol and diltiazem. Both classes show comparable efficacy and safety profiles with trends favoring diltiazem16, 17.

Algorithm for the management of atrial fibrillation with rapid ventricular response:

Algorithm for the management of atrial fibrillation with rapid ventricular response

References

  1. Atzema, C.L. and T.W. Barrett, Managing atrial fibrillation. Ann Emerg Med, 2015. 65(5): p. 532-9.
  2. January, C.T., et al., 2014 AHA/ACC/HRS Guideline for the Management of Patients With Atrial Fibrillation: Executive Summary. A Report of the American College of Cardiology/American Heart Association Task Force on Practice Guidelines and the Heart Rhythm Society, 2014. 64(21): p. 2246-2280.
  3. Scheuermeyer, F.X., et al., Emergency Department Patients With Atrial Fibrillation or Flutter and an Acute Underlying Medical Illness May Not Benefit From Attempts to Control Rate or Rhythm. Ann Emerg Med, 2015. 65(5): p. 511-522 e2.
  4. Stiell, I.G., et al., Association of the Ottawa Aggressive Protocol with rapid discharge of emergency department patients with recent-onset atrial fibrillation or flutter. CJEM, 2010. 12(3): p. 181-91.
  5. von Besser, K. and A.M. Mills, Is discharge to home after emergency department cardioversion safe for the treatment of recent-onset atrial fibrillation? Ann Emerg Med, 2011. 58(6): p. 517-20.
  6. Cohn, B.G., S.M. Keim, and D.M. Yealy, Is emergency department cardioversion of recent-onset atrial fibrillation safe and effective? J Emerg Med, 2013. 45(1): p. 117-27.
  7. Bellone, A., et al., Cardioversion of acute atrial fibrillation in the emergency department: a prospective randomised trial. Emerg Med J, 2012. 29(3): p. 188-91.
  8. Weigner, M.J., et al., Risk for clinical thromboembolism associated with conversion to sinus rhythm in patients with atrial fibrillation lasting less than 48 hours. Ann Intern Med, 1997. 126(8): p. 615-20.
  9. Airaksinen, K.E., et al., Thromboembolic complications after cardioversion of acute atrial fibrillation: the FinCV (Finnish CardioVersion) study. J Am Coll Cardiol, 2013. 62(13): p. 1187-92.
  10. Friberg, L., M. Rosenqvist, and G.Y. Lip, Evaluation of risk stratification schemes for ischaemic stroke and bleeding in 182 678 patients with atrial fibrillation: the Swedish Atrial Fibrillation cohort study. Eur Heart J, 2012. 33(12): p. 1500-10.
  11. Lip, G.Y., et al., Refining clinical risk stratification for predicting stroke and thromboembolism in atrial fibrillation using a novel risk factor-based approach: the euro heart survey on atrial fibrillation. Chest, 2010. 137(2): p. 263-72.
  12. Ntaios, G., et al., CHADS(2), CHA(2)S(2)DS(2)-VASc, and long-term stroke outcome in patients without atrial fibrillation. Neurology, 2013. 80(11): p. 1009-17.
  13. Lip, G.Y., et al., Comparative validation of a novel risk score for predicting bleeding risk in anticoagulated patients with atrial fibrillation: the HAS-BLED (Hypertension, Abnormal Renal/Liver Function, Stroke, Bleeding History or Predisposition, Labile INR, Elderly, Drugs/Alcohol Concomitantly) score. J Am Coll Cardiol, 2011. 57(2): p. 173-80.
  14. Pisters, R., et al., A novel user-friendly score (HAS-BLED) to assess 1-year risk of major bleeding in patients with atrial fibrillation: the Euro Heart Survey. Chest, 2010. 138(5): p. 1093-100.
  15. Goralnick, E. and L.J. Bontempo, Atrial Fibrillation. Emerg Med Clin North Am, 2015. 33(3): p. 597-612.
  16. Demircan, C., et al., Comparison of the effectiveness of intravenous diltiazem and metoprolol in the management of rapid ventricular rate in atrial fibrillation. Emerg Med J, 2005. 22(6): p. 411-4.
  17. Fromm, C., et al., Diltiazem vs. Metoprolol in the Management of Atrial Fibrillation or Flutter with Rapid Ventricular Rate in the Emergency Department. J Emerg Med, 2015. 49(2): p. 175-82.
  18. DiMarco, J.P., Atrial fibrillation and acute decompensated heart failure. Circ Heart Fail, 2009. 2(1): p. 72-3.

Blunt Cardiac Injury

Case Presentation

A 35-year-old female with no past medical history is brought in by ambulance to the emergency department. She was struck by a firework (“Roman Candle”) which lodged in her mid-chest until the propellant was consumed. She transiently lost consciousness but was awake upon EMS arrival. She complains of pleuritic chest pain. Examination reveals a circular 4x4cm full-thickness burn to the mid-chest with surrounding deep and superficial partial-thickness burns. Her ECG shows normal sinus rhythm, the initial serum troponin I is 32.9 (normal <0.012). CT angiography of the thorax is obtained.

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Mechanisms

Blunt cardiac injury (BCI) may be induced by multiple forces including direct thoracic trauma, crush injury of mediastinal contents between the sternum and thoracic spine, rapid deceleration causing tears at venous-atrial confluences, abrupt pressure changes from rapid compression of abdominal contents, blast injury, or laceration from bone fracture fragments1. The most common mechanisms of injury are motor vehicle collisions (50%), auto versus pedestrian (35%), motorcycle accidents (9%) and falls from significant height (>6m)2.

BCI represents a spectrum of conditions. Diagnosis is both challenging and critical as clinical manifestations can be absent or rapidly fatal.

At one end of the spectrum is myocardial contusion. The lack of a gold-standard for the diagnosis of this clinical entity has led to a preference for describing associated abnormalities if present3,4, including cardiac dysfunction (identified on echocardiography) or the next entity along the spectrum – arrhythmia.

The most common arrhythmia identified in blunt cardiac injury is sinus tachycardia, followed by premature atrial or ventricular contractions, T-wave changes, and atrial fibrillation or flutter5. Commotio cordis is a unique arrhythmia induced by untimely precordial impact (often in sports) during a vulnerable phase of ventricular excitability, resulting in ventricular fibrillation2.

ST-segment elevations after blunt cardiac injury should raise concern for myocardial infarction due to coronary artery dissection, laceration or thrombosis (often in already-diseased vessels) 5,6.

The remaining disease entities are increasingly rare, require careful examination or imaging for diagnosis, and are more likely to be non-survivable. Septal injury can range from small tears to rupture. Valvular injury most commonly affects the aortic valve (followed by mitral and tricuspid valves) and involves damage to leaflets, or rupture of papillary muscles or chordae tendineae. The clinical presentation is of acute valvular insufficiency, including acute heart failure and murmur2,7,8. A widened pulse pressure may be noted with aortic valve injury, and the manifestations of valvular injury may be delayed9. Finally, myocardial wall rupture is unlikely to be survivable, though patients may present with cardiac tamponade if rupture is small or contained2.

Evaluation

The primary diagnostic modalities for the assessment of BCI in the emergency department include assessment for pericardial fluid during the Focused Assessment with Sonography for Trauma (FAST), electrocardiography and cardiac enzymes.

While specific for identifying patients at risk of complications of BCI, electrocardiography alone is not sufficient to exclude BCI. In one study, only 59% of patient with echocardiographic evidence of BCI (wall-motion abnormalities, other chamber abnormalities) had initially abnormal ECG’s10. In another study, 41% of patients with initially normal ECG’s developed clinically significant abnormalities11. The use of specialized electrocardiography including right-sided ECG (proposed to better detect right-ventricular abnormalities which are more commonly associated with BCI) and signal-averaged ECG is not supported11,12.

Several studies have supported the use of serum troponin for the detection of clinically significant BCI – particularly in combination with electrocardiography. A prospective study in 2001 evaluating patients with blunt thoracic trauma using ECG at admission and 8-hours, as well as troponin I at admission, 4- and 8-hours had a negative predictive value of 100% for significant BCI (arrhythmia requiring treatment, shock, or structural cardiac abnormalities) in patients with initially normal ECG and troponin13.

Another prospective study adding to the population evaluated by Salim et al. included 41 patients with normal ECG’s and troponin levels at admission and 8-hours who were admitted for significant mechanisms, none developed significant BCI (again described as arrhythmia requiring treatment, shock, or structural cardiac abnormalities) after 1 to 3 days of observation14. The precise timing of serum troponin analysis remains unclear.

While FAST may detect hemopericardium warranting immediate intervention, formal echocardiography is indicated for patients with unexplained hypotension (to evaluate for valvular injury or regional wall-motion abnormalities) or persistent arrhythmias (to evaluate for arrhythmogenic intramural hematomas)15. The presence of sternal fractures was previously thought to increase risk of BCI and mandate echocardiography, however this notion is no longer supported16-18. The role of advanced imaging including helical CT (cardiac-gated), and MRI remains unclear19.

Algorithm for the Evaluation of Blunt Thoracic Trauma

Notes:
† Arrest in ED, immediate chest tube output >20ml/kg (>1.5L) or >200mL/hr for 2-4hr.

Management

Management of BCI depends on the pathologic process localized along the spectrum defined above. Persistent hypotension after appropriate evaluation for alternative etiologies may represent myocardial contusion with cardiac dysfunction and should be evaluated with echocardiography. Similarly, echocardiography and observation with continuous telemetry monitoring is indicated for any new arrhythmia or persistent and unexplained tachycardia. Patients with only elevation of the serum troponin without electrocardiographic abnormalities or obvious cardiac dysfunction should also be admitted for observation and serial cardiac enzymes. Traumatic myocardial infarction, valvular injury, or post-traumatic structural myocardial defects should be managed in consultation with cardiothoracic surgery5,19-21.

Case Conclusion

The CT interpretation noted the soft-tissue defect identified on examination as well as associated pulmonary contusions and a non-displaced sternal fracture. The patient went to the operating room for washout and debridement. A transthoracic echocardiogram demonstrated trace mitral regurgitation and a small pericardial effusion. She remained hemodynamically stable and serial troponin measures downtrended – no dysrhythmias were noted on telemetry monitoring. She was discharged on hospital day four with a negative-pressure wound dressing.

References

  1. Schultz JM, Trunkey DD. Blunt cardiac injury. Crit Care Clin. 2004;20(1):57-70.
  2. Yousef R, Carr JA. Blunt cardiac trauma: a review of the current knowledge and management. Ann Thorac Surg. 2014;98(3):1134-1140. doi:10.1016/j.athoracsur.2014.04.043.
  3. Mattox KL, Flint LM, Carrico CJ, et al. Blunt cardiac injury. The Journal of Trauma: Injury, Infection, and Critical Care. 1992;33(5):649-650.
  4. Sybrandy KC, Cramer MJM, Burgersdijk C. Diagnosing cardiac contusion: old wisdom and new insights. Heart. 2003;89(5):485-489.
  5. Elie M-C. Blunt cardiac injury. Mt Sinai J Med. 2006;73(2):542-552.
  6. Edouard AR, Felten M-L, Hebert J-L, Cosson C, Martin L, Benhamou D. Incidence and significance of cardiac troponin I release in severe trauma patients. Anesthesiology. 2004;101(6):1262-1268.
  7. Cordovil A, Fischer CH, Rodrigues ACT, et al. Papillary Muscle Rupture After Blunt Chest Trauma. Journal of the American Society of Echocardiography. 2006;19(4):469.e1-469.e3. doi:10.1016/j.echo.2005.12.005.
  8. Pasquier M, Sierro C, Yersin B, Delay D, Carron P-N. Traumatic Mitral Valve Injury After Blunt Chest Trauma: A Case Report and Review of the Literature. The Journal of Trauma: Injury, Infection, and Critical Care. 2010;68(1):243-246. doi:10.1097/TA.0b013e3181bb881e.
  9. Ismailov RM, Weiss HB, Ness RB, Lawrence BA, Miller TR. Blunt cardiac injury associated with cardiac valve insufficiency: trauma links to chronic disease? Injury. 2005;36(9):1022-1028. doi:10.1016/j.injury.2005.05.028.
  10. García-Fernández MA, López-Pérez JM, Pérez-Castellano N, et al. Role of transesophageal echocardiography in the assessment of patients with blunt chest trauma: correlation of echocardiographic findings with the electrocardiogram and creatine kinase monoclonal antibody measurements. Am Heart J. 1998;135(3):476-481.
  11. Fulda GJ, Giberson F, Hailstone D, Law A, Stillabower M. An evaluation of serum troponin T and signal-averaged electrocardiography in predicting electrocardiographic abnormalities after blunt chest trauma. The Journal of Trauma: Injury, Infection, and Critical Care. 1997;43(2):304–10–discussion310–2.
  12. Walsh P, Marks G, Aranguri C, et al. Use of V4R in patients who sustain blunt chest trauma. The Journal of Trauma: Injury, Infection, and Critical Care. 2001;51(1):60-63.
  13. Salim A, Velmahos GC, Jindal A, et al. Clinically significant blunt cardiac trauma: role of serum troponin levels combined with electrocardiographic findings. The Journal of Trauma: Injury, Infection, and Critical Care. 2001;50(2):237-243.
  14. Velmahos GC, Karaiskakis M, Salim A, et al. Normal electrocardiography and serum troponin I levels preclude the presence of clinically significant blunt cardiac injury. The Journal of Trauma: Injury, Infection, and Critical Care. 2003;54(1):45–50–discussion50–1. doi:10.1097/01.TA.0000046315.73441.D8.
  15. Nagy KK, Krosner SM, Roberts RR, Joseph KT, Smith RF, Barrett J. Determining which patients require evaluation for blunt cardiac injury following blunt chest trauma. World J Surg. 2001;25(1):108-111.
  16. Roy-Shapira A, Levi I, Khoda J. Sternal fractures: a red flag or a red herring? The Journal of Trauma: Injury, Infection, and Critical Care. 1994;37(1):59-61.
  17. Hills MW, Delprado AM, Deane SA. Sternal fractures: associated injuries and management. The Journal of Trauma: Injury, Infection, and Critical Care. 1993;35(1):55-60.
  18. Rashid MA, Ortenwall P, Wikström T. Cardiovascular injuries associated with sternal fractures. Eur J Surg. 2001;167(4):243-248. doi:10.1080/110241501300091345.
  19. Clancy K, Velopulos C, Bilaniuk JW, et al. Screening for blunt cardiac injury: an Eastern Association for the Surgery of Trauma practice management guideline. J Trauma Acute Care Surg. 2012;73(5 Suppl 4):S301-S306. doi:10.1097/TA.0b013e318270193a.
  20. El-Menyar A, Thani Al H, Zarour A, Latifi R. Understanding traumatic blunt cardiac injury. Ann Card Anaesth. 2012;15(4):287-295. doi:10.4103/0971-9784.101875.
  21. Hockberger RS, Walls RM. Rosen’s Emergency Medicine. Mosby Incorporated; 2002.

ECG Guide: Pediatrics

ECG Standard

  • Full standard: no adjustment
  • Half-standard: commensurate reduction in amplitude (usually 50%)
  • Mixed: reduction in amplitude of precordial leads

Atrial Abnormalities

Right Atrial Abnormality (P pulmonale)
Peaked P-wave in II (>3mm from 0-6mo or >2.5mm >6mo)
Causes: right atrial volume overload, ASD, Ebstein, Fontan
Left Atrial Abnormality (P mitrale)
Wide, notched P-wave in II or biphasic in V1
Causes: MS, MR

Axis

  • Anatomical dominance of right ventricle until approximately 6mo
  • RAD normal
  • eRAD suggests AV canal defect

T-waves

  • 1st week of life: Upright
  • Adolescent: Inverted
  • Adult: Upright

Ventricular Hypertrophy

Right Ventricular Hypertrophy
R-wave height >98% for age in lead V1
S-wave depth >98% for age in lead V6
T-wave abnormality (ex. upright in childhood)
Causes: pHTN, PS, ToF
Left Ventricular Hypertrophy
R-wave height >98% for age in lead V6
S-wave depth >98% for age in lead V1
Adult-pattern R-wave progression in newborn (no large R-waves and small S-waves in right precordial leads)
Left-axis deviation
Causes: AS, coarctation, VSD, PDA

Examples


Normal Neonatal ECG

  • 2mo old
  • RAD
  • Inverted T-waves (normal)
  • Tall R-waves in V1-V3


Extreme Axis Deviation

  • Neonate with Down syndrome
  • Isoelectric in I, Negative in aVF negative in II  mean QRS vector -87°
  • Extreme RAD suggestive of AV canal defect


LVH:

  • Unrepaired Coarctation
  • Deep S-wave in V1 (>98%)
  • Tall R-wave in V6 (>98%)


RVH:

  • 10 year-old boy with pulmonary Hypertension
  • RAD after expected age for normal RAD
  • Tall R-waves in V1 (>98%)
  • Deep S-wave in V6 (>98%)


STEMI

  • ALCAPA (anomalous origin of the left coronary artery from the pulmonary artery): coronary artery arises anomalously from the pulmonary artery; as pulmonary arterial pressure falls during the first 6 months of infancy, prograde flow through the left coronary artery ceases and may even reverse.
  • HLHS (hypoplastic left heart syndrome): coronary arteries are perfused from a hypoplastic, narrow aorta that is susceptible to flow disruption
  • Orthotopic heart transplant with allograft vasculopathy
  • Kawasaki: coronary artery aneurysm with subsequent thrombosis


Benign early repolarization

  • 14 year-old male
  • Concave ST-segment elevation


Left Atrial Abnormality:

  • 9mo female with mitral insufficiency
  • Broad biphasic P-wave in V1
  • Tall, notched P-wave in II


Prolonged QT interval

  • 18-year-old female
  • Familial long QT syndrome and a history of cardiac arrest


WPW:

  • Delta wave, shortened PR interval

References

  1. O’Connor M, McDaniel N, Brady WJ. The pediatric electrocardiogram. Part I: Age-related interpretation. Am J Emerg Med. 2008;26(2):221-228. doi:10.1016/j.ajem.2007.08.003.
  2. Goodacre S, McLeod K. ABC of clinical electrocardiography: Paediatric electrocardiography. BMJ. 2002;324(7350):1382-1385.
  3. O’Connor M, McDaniel N, Brady WJ. The pediatric electrocardiogram Part II: Dysrhythmias. Am J Emerg Med. 2008;26(3):348-358. doi:10.1016/j.ajem.2007.07.034.
  4. O’Connor M, McDaniel N, Brady WJ. The pediatric electrocardiogram Part III: Congenital heart disease and other cardiac syndromes. Am J Emerg Med. 2008;26(4):497-503. doi:10.1016/j.ajem.2007.08.004.
  5. Schwartz P. Guidelines for the interpretation of the neonatal electrocardiogram. Eur Heart J. 2002;23(17):1329-1344. doi:10.1053/euhj.2002.3274.

Bradycardia

Brief H&P:

A 38 year-old male with no medical history presents to the emergency department with abdominal pain. He had one episode each of non-bloody emesis followed by watery, non-bloody diarrhea and cited several sick contacts at home with similar symptoms. Vital signs were notable for bradycardia with a heart rate ranging from 38-46bpm though he was normotensive. The examination including abdominal examination was benign. A 12-lead electrocardiogram was obtained which demonstrated sinus bradycardia. The patient was asymptomatic during episodes of bradycardia and his heart rate responded appropriately during activity and on further history reported that he was an endurance athlete and runs multiple marathons each year. He was discharged after symptomatic improvement with anti-emetics.

Bradycardia 1

  • Definition: heart rate <60bpm
  • Sinus rhythm: upright P-wave in I, II, aV; inverted P-wave in aVR

Electrocardiographic Findings 1-4

  • Sinus bradycardia
    • Potentially asymptomatic and present in healthy individuals
  • Sinoatrial node dysfunction (sick sinus syndrome, SSS) 5,6
    • Sinus bradycardia
    • Sinus arrest
    • Tachy-brady syndrome (sinus bradycardia/arrest interspersed with SVT)
  • Atrioventricular block
    • 1st degree: PR prolongation, rarely symptomatic
    • 2nd degree: Intermittent interruption of conduction of atrial impulses to ventricles
      • Type 1: progressive PR prolongation leading to interrupted conduction
      • Type 2: fixed PR interval with interrupted conduction
    • 3rd degree: atrioventricular dissociation
  • Slow atrial fibrillation
    • Irregular RR interval without recognizable P-wave

Epidemiology7

  • Analysis of 277 patients presenting to the emergency department with “compromising” bradycardia.
  • Symptoms
    • Syncope (33%)
    • Dizziness (22%)
    • Angina (17%)
    • Dyspnea/Heart Failure (11%)
  • ECG
    • High-grade AV block (48%)
    • Sinus bradycardia (17%)
    • Sinus arrest (15%)
    • Slow atrial fibrillation (14%)
  • Cause
    • Primary (49%)
    • Drug (21%)
    • Ischemia/Infarction (14%)
    • Pacemaker failure (6%)
    • Intoxication (6%)
    • Electrolyte disorder (4%)

Important Historical Features8,9

  • Fever/travel
  • Chest pain
  • Cold intolerance, weight gain
  • Headache, AMS, trauma
  • Abdominal pain/distension
  • Medication changes

Important Examination Findings8,9

  • Perfusion (temperature, capillary refill)
  • Presence of fistula or hemodialysis catheter
  • Existing device (malfunction)

Workup8,9

  • ECG
  • Continuous telemetry monitoring
  • Labs
    • Potassium
    • Digoxin level
    • TFT
    • Infection titers (RPR, Lyme)
    • Cardiac enzymes

Management8,10

  • Unstable
    • Airway
    • Atropine 0.5mg IV q3-5min (maximum 3mg)
    • Dopamine/epinephrine infusion
    • Temporary pacemaker (transcutaneous, transvenous) with blood-pressure preserving sedation
    • Admission and evaluation for permanent pacemaker placement
  • Stable (outpatient evaluation)
    • Event monitor
    • Stress test (chronotropic incompetence)

Algorithm for the Evaluation and Management of Bradycardia

Algorithm for the evaluation and management of bradycardia

References

  1. Mangrum JM, DiMarco JP. The evaluation and management of bradycardia. N Engl J Med. 2000;342(10):703-709. doi:10.1056/NEJM200003093421006.
  2. Ufberg JW, Clark JS. Bradydysrhythmias and atrioventricular conduction blocks. Emergency Medicine Clinics of NA. 2006;24(1):1–9–v. doi:10.1016/j.emc.2005.08.006.
  3. Hayden GE, Brady WJ, Pollack M, Harrigan RA. Electrocardiographic manifestations: diagnosis of atrioventricular block in the Emergency Department. J Emerg Med. 2004;26(1):95-106. doi:10.1016/j.jemermed.2003.10.001.
  4. Da Costa D, Brady WJ, Edhouse J. Bradycardias and atrioventricular conduction block. BMJ. 2002;324(7336):535-538.
  5. Semelka M, Gera J, Usman S. Sick sinus syndrome: a review. Am Fam Physician. 2013;87(10):691-696.
  6. Ewy GA. Sick sinus syndrome: synopsis. J Am Coll Cardiol. 2014;64(6):539-540. doi:10.1016/j.jacc.2014.05.029.
  7. Sodeck GH, Domanovits H, Meron G, et al. Compromising bradycardia: management in the emergency department. Resuscitation. 2007;73(1):96-102. doi:10.1016/j.resuscitation.2006.08.006.
  8. Deal N. Evaluation and management of bradydysrhythmias in the emergency department. Emergency Medicine Practice. 2013;15(9):1–15–quiz15–6.
  9. Demla V, Rohra A. Emergency Department Evaluation and Management of Bradyarrhythmia. Hospital Medicine Clinics. 2015;4(4):526-539. doi:https://doi.org/10.1016/j.ehmc.2015.06.009.
  10. Brady WJ, Harrigan RA. Evaluation and management of bradyarrhythmias in the emergency department. Emergency Medicine Clinics of NA. 1998;16(2):361-388.

Nonsustained Ventricular Tachycardia

Case 1

64M with a history of HFrEF (LVEF 20-25%), CAD, AICD (unknown indication), COPD, CKD III presenting with gradual onset shortness of breath, progressive bilateral lower extremity edema.
Examination consistent with severe acute decompensated heart failure presumed secondary to left ventricular dysfunction.
Telemetry monitoring with multiple episodes of nonsustained ventricular tachycardia.

In the ED, the patient developed worsening respiratory failure despite initiation of therapy, requiring endotracheal intubation. Continuous cardiac monitoring revealed persistent salvos of NSVT, progressing to slow ventricular tachycardia without device intervention.
Device interrogation revealed multiple events, 3 shocks, several ATP’s over the recorded period.

Evaluation and Management:

  • NSVT with known (severe) ischemic heart disease
  • For repetitive monomorphic ventricular tachycardia: amiodarone, beta-blockade (if tolerated), procainamide (IIA, C)1

ECG’s

ECG 1
ECG 1

ECG 1

Non-specific IVCD, LAA, VPC

ECG 2
ECG 2

ECG 2

VT initiated by fusion complex

Case 2

31F with autoimmune polyglandular syndrome (adrenal, thyroid and endocrine pancreatic insufficiency), presenting with fever and cough.
Evaluation consistent with sepsis presumed secondary to pulmonary source.
Telemetry monitoring initially with ventricular bigeminy, then nonsustained ventricular tachycardia.

In the ED, the patient developed pulseless ventricular tachycardia – apparently polymorphic. Chest compressions and epinephrine produced return of spontaneous circulation with recovery to baseline neurologic function.
ECG revealed prolonged QTc and chemistry panel notable for critical hypokalemia/hypomagnesemia.

Evaluation and Management:

  • NSVT progressing to VT
  • Initially attributed to electrolyte disturbances. However, serial ECG’s continued to show prolonged QTc (possibly acquired, home medications included metoclopramide and erythromycin). Early echocardiography demonstrated global hypokinesis with EF 30-35% attributed to severe sepsis and recurrent defibrillation. Cardiac CT after resolution of acute illness showed persistently depressed ejection fraction without coronary atherosclerosis. The presence of NICM associated with malignant dysrhythmias warranted ICD placement.
  • Cardioversion for hemodynamic compromise (I, B), B-blockade (I, B), amiodarone if no LQTS (I, C), urgent angiography if ischemia not excluded (I, C)1
  • Correction of electrolyte abnormalities (specifically hypokalemia) may decrease progression to VF.2

ECG’s

ECG 1
ECG 1

ECG 1

Ventricular bigeminy

ECG 2
ECG 2

ECG 2

Long-QT

VT on Telemetry
VT on Telemetry

VT on Telemetry

Non-sustained ventricular tachycardia noted on telemetry monitoring

Definition3,4

  • > 3-5 consecutive beats originating below the AV node
  • Rate > 100bpm
  • Duration <30s

Epidemiology3,5

  • Occurs in 0-4% of ambulatory patients
  • Increased frequency in males and with increasing age

    • In some patients, NSVT is associated with an increased risk of sustained tachyarrhythmias and sudden cardiac death. In others it is of little prognostic significance.6,7,8

Evaluation

In all patients:
History: including arrhythmogenic medications/substances, pertinent family history
Physical examination
ECG/CXR
TTE
In selected patients:
Exercise testing
Advanced imaging (CT/C-MR)
Electrophysiologic studies
Genetic testing

NSVT in the absence of structural heart disease

NSVT in Idiopathic Ventricular Tachycardia

Ventricular outflow arrhythmias:
RVOT: 70-80%, LBBB pattern
LVOT: 20-30%, RBBB pattern
Mechanism:
Adrenergically mediated
Occur during exercise, resolve as heart-rate increases, recur during recovery
Management:
Exclude arrhythmogenic right ventricular cardiomyopathy (imaging, myocardial biopsy)
If symptomatic, beta-blockade, ± IC anti-arrhythmic, CCB (verapamil) for ILVT
Prognosis:
Good, rare tachycardia-induced cardiomyopathy, rare SCD

NSVT in Polymorphic Ventricular Tachycardia

Mechanism
LQTS (acquired or inherited)
Familial catecholaminergic polymorphic VT
Management
Symptomatic (ex. syncope, cardiac arrest): ICD
Asymptomatic QTc > 550ms: consider ICD
Prognosis
Increased risk SCD

Arrhythmogenic Right Ventricular Cardiomyopathy

Mechanism
Fibrosis, fibro-fatty replacement of myocardium in RVIT/RVOT/RV apex
May occur with only subtle structural abnormalities of the right ventricle
LBBB morphology
Management
Anti-arrhythmics of limited utility
Catheter ablation, ICD backup
Prognosis
Increased risk SCD

NSVT with apparent structural heart disease1

Hypertension and LVH

Mechanism
Stretch-induced abnormal automaticity
Fibrotic tissue
Presence of NSVT correlates with degree of hypertrophy and subendocardial fibrosis
Management
Evaluation for ischemic heart disease
Aggressive medical management of hypertension (including beta-blockade)
Prognosis
Unclear

Valvular Disease

Mechanism
High incidence in AS, severe MR (25%)
Mechanical stress from dysfunctional valvular apparatus
Management
Beta-blockade if symptomatic
Prognosis
No evidence that NSVT is an independent predictor of SCD.

Ischemic Heart Disease9-14

Mechanism
Monomorphic VT associated with re-entry at the borders of ventricular scars
Ischemia induces polymorphic NSVT/VF
Management
Revascularization, beta-blockade, statin, ACE/ARB
MADIT I, MUSTT: ICD for ICM LVEF <40%, NSVT, EPS inducible VT
MADIT II, SCD-HeFT: ICD for moderate-to-severe LV dysfunction irrespective of NSVT or EPS findings
Prognosis
NSTEMI with NSVT >48h after admission 2x risk SCD (MERLIN-TIMI 36)
STEMI with NSVT common, not as predictive of ACM or SCD as LVEF (CARISMA)
NSVT <24h after admission for NSTEMI/STEMI not of prognostic significance.

Hypertrophic Cardiomyopathy

Mechanism
Genetic myocardial disease
Myocyte disarray, fibrosis, ischemia result in arrhythmogenic substrate
Management
Restriction of physical activity
ICD (NSVT, LV thickness, FH SCD, syncope, abnormal BP response to exercise)
Beta-blockade, anti-arrhythmic for symptoms
Prognosis
Increased risk SCD (1% annual)

Other Conditions

  • Non-ischemic dilated cardiomyopathy
  • Giant-cell myocarditis
  • Repaired TOF
  • Amyloidosis
  • Sarcoidosis
  • Chagas cardiomyopathy

Algorithm for the Evaluation of NSVT1

Algorithm for the Evaluation of Nonsustained Ventricular Tachycardia

References

  1. Zipes DP, Camm AJ, Borggrefe M, et al. ACC/AHA/ESC 2006 guidelines for management of patients with ventricular arrhythmias and the prevention of sudden cardiac death–executive summary: A report of the American College of Cardiology/American Heart Association Task Force and the European Society of Cardiology Committee for Practice Guidelines (Writing Committee to Develop Guidelines for Management of Patients with Ventricular Arrhythmias and the Prevention of Sudden Cardiac Death) Developed in collaboration with the European Heart Rhythm Association and the Heart Rhythm Society. Eur Heart J. 2006;27(17):2099–2140. doi:10.1093/eurheartj/ehl199.
  2. Higham PD, Adams PC, Murray A, Campbell RW. Plasma potassium, serum magnesium and ventricular fibrillation: a prospective study. Q J Med. 1993;86(9):609–617.
  3. Katritsis DG, Zareba W, Camm AJ. Nonsustained ventricular tachycardia. J Am Coll Cardiol. 2012;60(20):1993–2004. doi:10.1016/j.jacc.2011.12.063.
  4. Katritsis DG, Camm AJ. Nonsustained ventricular tachycardia: where do we stand? Eur Heart J. 2004;25(13):1093–1099. doi:10.1016/j.ehj.2004.03.022.
  5. Wellens HJ. Electrophysiology: Ventricular tachycardia: diagnosis of broad QRS complex tachycardia. Heart. 2001;86(5):579–585.
  6. Buxton AE, Lee KL, Fisher JD, Josephson ME, Prystowsky EN, Hafley G. A randomized study of the prevention of sudden death in patients with coronary artery disease. Multicenter Unsustained Tachycardia Trial Investigators. N Engl J Med. 1999;341(25):1882–1890. doi:10.1056/NEJM199912163412503.
  7. Jouven X, Zureik M, Desnos M, Courbon D, Ducimetière P. Long-term outcome in asymptomatic men with exercise-induced premature ventricular depolarizations. N Engl J Med. 2000;343(12):826–833. doi:10.1056/NEJM200009213431201.
  8. Udall JA, Ellestad MH. Predictive implications of ventricular premature contractions associated with treadmill stress testing. Circulation. 1977;56(6):985–989.
  9. Preliminary report: effect of encainide and flecainide on mortality in a randomized trial of arrhythmia suppression after myocardial infarction. The Cardiac Arrhythmia Suppression Trial (CAST) Investigators. N Engl J Med. 1989;321(6):406–412. doi:10.1056/NEJM198908103210629.
  10. Goldstein S. Propranolol therapy in patients with acute myocardial infarction: the Beta-Blocker Heart Attack Trial. Circulation. 1983;67(6 Pt 2):I53–7.
  11. Moss AJ. MADIT-I and MADIT-II. J Cardiovasc Electrophysiol. 2003;14(9 Suppl):S96–8.
  12. Moss AJ, Hall WJ, Cannom DS, et al. Improved survival with an implanted defibrillator in patients with coronary disease at high risk for ventricular arrhythmia. Multicenter Automatic Defibrillator Implantation Trial Investigators. N Engl J Med. 1996;335(26):1933–1940. doi:10.1056/NEJM199612263352601.
  13. Buxton AE, Lee KL, Fisher JD, Josephson ME, Prystowsky EN, Hafley G. A randomized study of the prevention of sudden death in patients with coronary artery disease. Multicenter Unsustained Tachycardia Trial Investigators. N Engl J Med. 1999;341(25):1882–1890. doi:10.1056/NEJM199912163412503.
  14. Bardy GH, Lee KL, Mark DB, et al. Amiodarone or an implantable cardioverter-defibrillator for congestive heart failure. N Engl J Med. 2005;352(3):225–237. doi:10.1056/NEJMoa043399.
  15. WikEM: Nonsustained Ventricular Tachycardia