Sandbox/NCT: Difference between revisions
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==Treatment== | ==Treatment== | ||
===Initial Approach=== | ===Initial Approach=== | ||
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===Short Term Treatment of SVT in a Hemodynamically Stable Patient=== | ===Short Term Treatment of SVT in a Hemodynamically Stable Patient=== | ||
Shown below is an algorithm summarizing the management of narrow complex tachycardia according to the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias.<ref name="circ.ahajournals.org">{{Cite web | last = | first = | title = ACC/AHA/ESC Guidelines for the Management of Patients With Supraventricular Arrhythmias—Executive Summary | url = http://circ.ahajournals.org/content/108/15/1871 | publisher = | date = | accessdate = 15 August 2013 }}</ref> <br> | Shown below is an algorithm summarizing the management of narrow complex tachycardia according to the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias.<ref name="circ.ahajournals.org">{{Cite web | last = | first = | title = ACC/AHA/ESC Guidelines for the Management of Patients With Supraventricular Arrhythmias—Executive Summary | url = http://circ.ahajournals.org/content/108/15/1871 | publisher = | date = | accessdate = 15 August 2013 }}</ref> <br> | ||
<span style="font-size:85%"> | <span style="font-size:85%">'''AF''': atrial fibrillation; '''AV''': atrioventricular; '''AVNRT''': atrioventricular nodal reciprocating tachycardia; '''AVRT''': atrioventricular reciprocating tachycardia; '''BBB''': bundle-branch block; '''ECG''': electrocardiography; ''' IV''': intravenous; '''LV''': left ventricle; '''SVT''': supraventricular tachycardia; '''VT''': ventricular tachycardia </span> | ||
{{familytree/start}} | {{familytree/start}} | ||
{{familytree | | | D01 | | D01=<div style="float: left; text-align: left; width: 35em; padding:1em;">'''Acute management:'''<br> | {{familytree | | | D01 | | D01=<div style="float: left; text-align: left; width: 35em; padding:1em;">'''Acute management:'''<br> | ||
❑ Perform vagal maneuvers ([[ACC AHA guidelines classification scheme|Class I, level of evidence B]])<br> | ❑ Perform vagal maneuvers ([[ACC AHA guidelines classification scheme|Class I, level of evidence B]])<br> | ||
: ❑ [[Valsalva maneuver]]<br> | : ❑ [[Valsalva maneuver]]<br> | ||
: ❑ Carotid massage<br> | : ❑ [[Carotid sinus massage]]<br> | ||
❑ Monitor [[ECG]] continuously</div>}} | ❑ Monitor [[ECG]] continuously</div>}} | ||
{{familytree | | | |!| | | | |}} | {{familytree | | | |!| | | | |}} | ||
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❑ Monitor [[ECG]] continuously </div>}} | ❑ Monitor [[ECG]] continuously </div>}} | ||
{{familytree | | | |!| | | }} | {{familytree | | | |!| | | }} | ||
{{familytree | | | C01 | |C01=<div style="float: left; text-align: left; width: 35em; padding:1em;">❑ Assess changes on [[ECG]] following adenosine administration | {{familytree | | | C01 | |C01=<div style="float: left; text-align: left; width: 35em; padding:1em;">❑ Assess changes on [[ECG]] following [[adenosine]] administration | ||
<table class="wikitable"> | <table class="wikitable"> | ||
<tr class="v-firstrow"><th>Changes on ECG</th><th> Possible causes</th></tr> | <tr class="v-firstrow"><th>Changes on ECG</th><th> Possible causes</th></tr> | ||
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:❑ Maintenance infusion of 5-15 mg/hour<ref name="pmid16525141">{{cite journal| author=Delacrétaz E| title=Clinical practice. Supraventricular tachycardia. | journal=N Engl J Med | year= 2006 | volume= 354 | issue= 10 | pages= 1039-51 | pmid=16525141 | doi=10.1056/NEJMcp051145 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16525141 }} </ref> | :❑ Maintenance infusion of 5-15 mg/hour<ref name="pmid16525141">{{cite journal| author=Delacrétaz E| title=Clinical practice. Supraventricular tachycardia. | journal=N Engl J Med | year= 2006 | volume= 354 | issue= 10 | pages= 1039-51 | pmid=16525141 | doi=10.1056/NEJMcp051145 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16525141 }} </ref> | ||
❑ IV [[beta blocker]] ([[ACC AHA guidelines classification scheme|Class IIb, level of evidence C]])<br> | ❑ IV [[beta blocker]] ([[ACC AHA guidelines classification scheme|Class IIb, level of evidence C]])<br> | ||
: | :❑ [[Metoprolol]] <br> | ||
:❑ 5 mg over 2 minutes | ::❑ 5 mg over 2 minutes | ||
:❑ Up to 3 doses within 15 minutes | ::❑ Up to 3 doses within 15 minutes | ||
: | :❑ [[Esmolol]] <br> | ||
:❑ 250-500 μg/kg over 1 minute | ::❑ 250-500 μg/kg over 1 minute | ||
:❑ Maintenance with 50-200 μg/kg over 4 minutes (if needed) | ::❑ Maintenance with 50-200 μg/kg over 4 minutes (if needed) | ||
: | :❑ [[Propranolol]] <br> | ||
:❑ 0.15 mg/kg over 2 minutes<ref name="pmid16525141">{{cite journal| author=Delacrétaz E| title=Clinical practice. Supraventricular tachycardia. | journal=N Engl J Med | year= 2006 | volume= 354 | issue= 10 | pages= 1039-51 | pmid=16525141 | doi=10.1056/NEJMcp051145 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16525141 }} </ref> | ::❑ 0.15 mg/kg over 2 minutes<ref name="pmid16525141">{{cite journal| author=Delacrétaz E| title=Clinical practice. Supraventricular tachycardia. | journal=N Engl J Med | year= 2006 | volume= 354 | issue= 10 | pages= 1039-51 | pmid=16525141 | doi=10.1056/NEJMcp051145 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=16525141 }} </ref> | ||
---- | ---- | ||
❑ Monitor [[ECG]] continuously </div>}} | ❑ Monitor [[ECG]] continuously </div>}} |
Revision as of 04:34, 27 March 2014
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Hilda Mahmoudi M.D., M.P.H.[2]; Twinkle Singh, M.B.B.S. [3]; Rim Halaby, M.D. [4]
Narrow Complex Tachycardia Resident Survival Guide Microchapters |
---|
Overview |
Causes |
Diagnosis |
Treatment |
Do's |
Don'ts |
Overview
Narrow complex tachycardia (NCT) is characterized by heart rate > 100 beats per minute and QRS complex of duration < 120 milliseconds. The NCT may originate in the sinus node, the atria, the AV node, the His bundle, or combination of these tissues causing rapid activation of the ventricles. Diagnosis of NCT is established by surface ECG in correlation with history and physical examination. Hemodynamically unstable patients should receive urgent cardioversion.
Causes
Life Threatening Causes
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated.
Common Causes
Diagnosis
Shown below is an algorithm summarizing the approach for diagnosing narrow complex tachycardia according to the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias.[1]
ECG: electrocardiogram; SVT: supraventricular tachycardia; ms: Milliseconds; bpm: beats per minute; NCT: Narrow complex tachycardia; AV: atrioventricular; AVNRT: atrioventricular nodal reciprocating tachycardia; MAT: multifocal atrial tachycardia; ms: milliseconds; PJRT: permanent form of junctional reciprocating tachycardia
Characterize the symptoms: ❑ Asymptomatic (most common presentation) | |||||||||||||||||||||||||||||||||||||||||||||
Identify possible triggers: | |||||||||||||||||||||||||||||||||||||||||||||
Differential Diagnosis of NCT | |||||||||||||||||||||||||||||||||||||||||||||
Examine the patient: General appearance Vitals
Neck
Cardiovascular examination
| |||||||||||||||||||||||||||||||||||||||||||||
❑ Assess hemodynamic stability
❑ Order and monitor the ECG
❑ Give oxygen if needed | |||||||||||||||||||||||||||||||||||||||||||||
Narrow QRS tachycardia ❑ Heart rate > 100 beats/min ❑ QRS duration < 120 ms | |||||||||||||||||||||||||||||||||||||||||||||
❑ Determine the regularity of rhythm | |||||||||||||||||||||||||||||||||||||||||||||
Regular rhythm | Irregular rhythm | ||||||||||||||||||||||||||||||||||||||||||||
Consider the following causes: ❑ AVRT | Consider the following causes: ❑ Atrial fibrillation | ||||||||||||||||||||||||||||||||||||||||||||
❑ Determine P wave morphology | ❑ Determine P wave morphology | ||||||||||||||||||||||||||||||||||||||||||||
❑ P waves are not visible | ❑ P waves are visible | ❑ > 3 P wave morphologies | ❑ Absent P waves | ❑ Sawtooth appearance of P waves | |||||||||||||||||||||||||||||||||||||||||
❑ Consider AVNRT | ❑ Determine if atrial rate is greater than ventricular rate | MAT | Atrial fibrillation | Atrial flutter | |||||||||||||||||||||||||||||||||||||||||
Atrial rate > ventricular rate | Atrial rate ≤ ventricular rate | ||||||||||||||||||||||||||||||||||||||||||||
❑ Determine if RP interval > PR interval | |||||||||||||||||||||||||||||||||||||||||||||
RP < PR | RP > PR | ||||||||||||||||||||||||||||||||||||||||||||
❑ Determine the duration of RP interval | |||||||||||||||||||||||||||||||||||||||||||||
< 70 ms | > 70 ms | ||||||||||||||||||||||||||||||||||||||||||||
Consider the following cause: ❑ AVNRT | |||||||||||||||||||||||||||||||||||||||||||||
Treatment
Initial Approach
Shown below is an algorithm summarizing the initial approach for narrow complex tachycardia according to the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias.[1]Assess the hemodynamic stability of the patient | |||||||||||||||||||||||||||||||||||||||||||||
❑ Unstable patient | ❑ Stable patient | ||||||||||||||||||||||||||||||||||||||||||||
❑ If the rythm isn't sinus tachycardia: Urgent cardioversion | ❑ If the rythm is sinus tachycardia: ❑ Control the rate:
| Documented arrhythmia | Undocumented arrhythmia (ECG is normal) | ||||||||||||||||||||||||||||||||||||||||||
History suggestive of extra premature beats ❑ Sensation of a pause followed by a strong heart beat OR | History suggestive of paroxysmal arrhythmia ❑ Regular palpitations with sudden onset and termination | ||||||||||||||||||||||||||||||||||||||||||||
❑ Refer for an invasive electrophysiological study AND/OR ❑ Catheter ablation ❑ Educate about vagal maneuvers ❑ Consider beta blocker | |||||||||||||||||||||||||||||||||||||||||||||
Short Term Treatment of SVT in a Hemodynamically Stable Patient
Shown below is an algorithm summarizing the management of narrow complex tachycardia according to the 2003 ACC/AHA/ESC guidelines for the management of patients with supraventricular arrhythmias.[1]
AF: atrial fibrillation; AV: atrioventricular; AVNRT: atrioventricular nodal reciprocating tachycardia; AVRT: atrioventricular reciprocating tachycardia; BBB: bundle-branch block; ECG: electrocardiography; IV: intravenous; LV: left ventricle; SVT: supraventricular tachycardia; VT: ventricular tachycardia
Acute management: ❑ Perform vagal maneuvers (Class I, level of evidence B) | |||||||||||||||||||||||||||
If vagal maneuvers fail: ❑ Administer IV adenosine† (Class I, level of evidence A)
| |||||||||||||||||||||||||||
❑ Assess changes on ECG following adenosine administration
| |||||||||||||||||||||||||||
If adenosine fails, administer ONE of the following: ❑ IV verapamil 5 mg IV every 3-5 min, maximum 15 mg (Class I, level of evidence A)[2]
❑ IV beta blocker (Class IIb, level of evidence C)
❑ Monitor ECG continuously | |||||||||||||||||||||||||||
Terminated arrhythmia | Persistent arrhythmia | ||||||||||||||||||||||||||
No further therapy is required if: ❑ Patient is stable ❑ LV function is normal ❑ Normal sinus rhythm on ECG | ❑ Administer AV-nodal-blocking agent AND one of the following
OR | ||||||||||||||||||||||||||
† Adenosine should be used cautiously in patients with severe coronary artery disease and may produce AF.
‡ Ibutilide is especially indicated for patients with atrial flutter but should not be used in patients with ejection fraction less than 30% as it increases risk of polymorphic VT.
Type of Arrhythmia | EKG (lead II)† | Clues |
Supraventricular tachycardia | ![]() |
Any tachyarrhythmia that is initiated and maintained in atrial tissue or atrioventricular junctional tissue.[1] |
Sinus tachycardia | ![]() |
Rhythm with heart rate > 100 bpm, originating in SA node due to its increased automaticity. |
Sinus node re-entry tachycardia | Rare paroxysmal tachycardia arising due to re-entry circuits with in SA node.[3] | |
Atrial fibrillation | ![]() |
Supraventricular tachycardia with irregularly irregular rhythm and absent P waves on EKG. |
Atrial flutter | ![]() |
Cardiac rhythm characterized by an atrial rate ranging from 240 to 400 beats per minute and regular continuous wave-form.[4] |
AVNRT | ![]() |
Most common form of PSVT with a heart rate of 140-250 bpm, re-entrant circuit involves two separate anatomical pathways (slow and fast) loacted in perinodal tissue. |
AVRT | ![]() |
Re-entrant tachycardia occurring due to an accessory pathway in addition to AV node, accessory pathway is essential for the initiation and the maintenance of tachycardia. |
Focal atrial tachycardia | ![]() |
Focal atria tachycardia refers to a rhythm originating from a single site either in the left or right atrium with an atrial rate of 100-250 bpm. |
Nonparoxysmal junctional tachycardia | ![]() |
Benign tachycardia occurring due to increased automaticity arising from a high junctional focus. |
Multifocal atrial tachycardia | ![]() |
Irregular tachycardia characterized by 3 different P wave morphologies on EKG. |
† EKG strips are a courtesy from ECGpedia.
Do's
- Refer patients with narrow complex tachycardia with any of the following to a cardiac arrhythmia specialist:
- Drug resistance
- Intolerance to drugs
- Refusal of drug therapy
- Severe symptoms such as syncope and dyspnea
- Wolff-Parkinson-White syndrome[2]
- Consider trying different types of anti-arrhythmic agents in case the SVT is refractory; however, closely monitor the blood pressure and heart rate.[2]
- Consider invasive electrophysiological investigation in presence of pre-excitation and severe disabling symptoms.
- Monitor the 12 lead ECG during the administration ofadenosine or carotid massage.
- Make sure the equipment for resuscitation is available during the administration of adenosine in case of the occurrence of any complication, such as ventricular fibrillation or bronchospasm.[2]
- Consider esophageal pill electrodes in cases of invisible P waves.
- Administer higher doses of adenosine in patients taking theophylline.
- Perform the following tests when indicated:
- Echocardiography in case of sustained SVT to rule out structural heart disease
- 24 hour holter monitor in case of frequent but transient tachycardia
- Loop recorder in patients with less frequent arrhythmias
- Trans-esophageal atrial recordings if other investigations have failed to document an arrhythmia
Don'ts
- Do not perform esophageal stimulation if an invasive electrophysiological investigation is planned.
- Do not initiate treatment with anti-arrhythmic agents in a patient with undocumented arrhythmia.
- Do not administer adenosine in patients with severe bronchial asthma or heart transplant recipients.[2]
References
- ↑ 1.0 1.1 1.2 1.3 "ACC/AHA/ESC Guidelines for the Management of Patients With Supraventricular Arrhythmias—Executive Summary". Retrieved 15 August 2013.
- ↑ 2.0 2.1 2.2 2.3 2.4 2.5 2.6 2.7 2.8 Delacrétaz E (2006). "Clinical practice. Supraventricular tachycardia". N Engl J Med. 354 (10): 1039–51. doi:10.1056/NEJMcp051145. PMID 16525141.
- ↑ Cossú, SF.; Steinberg, JS. "Supraventricular tachyarrhythmias involving the sinus node: clinical and electrophysiologic characteristics". Prog Cardiovasc Dis. 41 (1): 51–63. PMID 9717859.
- ↑ Dhar S, Lidhoo P, Koul D, Dhar S, Bakhshi M, Deger FT (2009). "Current concepts and management strategies in atrial flutter". South. Med. J. 102 (9): 917–22. doi:10.1097/SMJ.0b013e3181b0f4b8. PMID 19668035. Unknown parameter
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