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| {{CMG}}; {{AE}}{{Aisha}} | | {{CMG}}; {{AE}}{{Aisha}} |
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| {{SK}} | | {{SK}} pVT |
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| ==[[Pulseless ventricular tachycardia overview|Overview]]== | | ==[[Pulseless ventricular tachycardia overview|Overview]]== |
| Pulseless ventricular tachycardia is an often fatal cardiac dysrhythmia where the regular rhythmic contraction of the heart is replaced by non-rhythmic, faster, yet inadequate contractions. These ineffective contractions do not appropriately perfuse the organ, leading to ischemia as well as heart failure. This condition requires immediate medical attention as it is an emergency and can lead to ventricular fibrillation and sudden death.<ref name="pmid32119354">{{cite journal |vauthors=Foglesong A, Mathew D |title= |journal= |volume= |issue= |pages= |date= |pmid=32119354 |doi= |url=}}</ref>
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| ==[[Pulseless ventricular tachycardia historical perspective|Historical Perspective]]== | | ==[[Pulseless ventricular tachycardia historical perspective|Historical Perspective]]== |
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| ==[[Pulseless ventricular tachycardia classification|Classification]]== | | ==[[Pulseless ventricular tachycardia classification|Classification]]== |
| [[Pulseless ventricular tachycardia]] as a [[ventricular tachycardia]], may be classified based on the [[morphology]] of the [[QRS complexes]] into two subtypes/groups: [[monomorphic ventricular tachycardia]], and [[polymorphic ventricular tachycardia]].
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| ==[[Pulseless ventricular tachycardia pathophysiology|Pathophysiology]]== | | ==[[Pulseless ventricular tachycardia pathophysiology|Pathophysiology]]== |
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| Rapid abnormal [[automaticity]] and [[triggered activity]] are thought to be the main [[electrophysiological]] mechanisms of [[pulseless ventricular tachycardia]]. In abnormal automatically, the ventricular myocytes produce strong, voluntary, and recurrent depolarization and subsequent contractions at a rate that is higher than normal. This is due to a due to a decrease (ranging between -70mV and -30mV) in normal [[resting membrane potential]]. The higher the reduction in [[membrane potential]], the faster and more rapid the already abnormal [[automaticity]].<ref name="pmid4237287">{{cite journal |vauthors=Armendares S, Pérez Treviño C |title=[Congenital heart diseases in chromosome abnormalities. I. In Down's syndrome (mongolism)] |language=Spanish; Castilian |journal=Arch Inst Cardiol Mex |volume=38 |issue=6 |pages=779–91 |date=1968 |pmid=4237287 |doi= |url=}}</ref> Triggered activity is used to depict the indication of impulse in cardiac myocytes that is dependent on [[afterdepolarizations]] (an oscillation in membrane potential that occurs after repolarization). Two types of afterdepolarizations have been identified: [[Early afterdepolarizations]](EAD) and [[Delayed afterdepolarizations]] (DAD). When either of these afterdepolarizations become high enough to reach the [[membrane threshold]], they result in a spontaneous "triggered" action potential. Hence for a triggered activity to occur, at least one action potential must precede it.<ref name="pmid1855225">{{cite journal |vauthors=Buchmann A, Ruggeri B, Klein-Szanto AJ, Balmain A |title=Progression of squamous carcinoma cells to spindle carcinomas of mouse skin is associated with an imbalance of H-ras alleles on chromosome 7 |journal=Cancer Res. |volume=51 |issue=15 |pages=4097–101 |date=August 1991 |pmid=1855225 |doi= |url=}}</ref>
| | ==[[Pulseless ventricular tachycardia causess|Causes]]== |
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| In pulseless ventricular tachycardia, the combination of increased automatically and/or triggered activity leads to a rate of contraction that is too rapid to result in adequate ventricular filling during diastole. This results in deficient cardiac output, inadequate perfusion of organs, and hemodynamic collapse.<ref name="pmid32119354">{{cite journal |vauthors=Foglesong A, Mathew D |title= |journal= |volume= |issue= |pages= |date= |pmid=32119354 |doi= |url=}}</ref>
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| ==[[Pulseless ventricular tachycardia causes|Causes]]== | |
| [[Structural heart disease]] is the most common cause of [[pulseless ventricular tachycardia]]. Other causes include but are not limited to, drugs/medications, [[congenital heart diseases]], not to mention congenital and inherited [[channelopathies]]. It is important to note that [[QT interval]] lengthening medications, as well as [[electrolyte]] disturbances, can also result in pulseless ventricular tachycardia.<ref name="pmid27484660">{{cite journal |vauthors=Baldzizhar A, Manuylova E, Marchenko R, Kryvalap Y, Carey MG |title=Ventricular Tachycardias: Characteristics and Management |journal=Crit Care Nurs Clin North Am |volume=28 |issue=3 |pages=317–29 |date=September 2016 |pmid=27484660 |doi=10.1016/j.cnc.2016.04.004 |url=}}</ref>
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| ==[[Pulseless ventricular tachycardia differential diagnosis|Differentiating Pulseless ventricular tachycardia from other Diseases]]== | | ==[[Pulseless ventricular tachycardia differential diagnosis|Differentiating Pulseless ventricular tachycardia from other Diseases]]== |
| Pulseless ventricular tachycardia must be differentiated from other diseases that cause wide complex tachycardia, such as [[supraventricular tachycardia with aberrant conduction]], SVT with pre-excitation and antidromic atrioventricular reentrant tachycardia.<ref name="pmid30267690">{{cite journal |vauthors= |title=Correction |journal=Heart Rhythm |volume=15 |issue=11 |pages=e282 |date=November 2018 |pmid=30267690 |doi=10.1016/j.hrthm.2018.09.024 |url=}}</ref>
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| ==[[Pulseless ventricular tachycardia epidemiology and demographics|Epidemiology and Demographics]]== | | ==[[Pulseless ventricular tachycardia epidemiology and demographics|Epidemiology and Demographics]]== |
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| Ventricular tachycardia and ventricular fibrillation<ref name="pmid29173411">{{cite journal |vauthors=Tang PT, Shenasa M, Boyle NG |title=Ventricular Arrhythmias and Sudden Cardiac Death |journal=Card Electrophysiol Clin |volume=9 |issue=4 |pages=693–708 |date=December 2017 |pmid=29173411 |doi=10.1016/j.ccep.2017.08.004 |url=}}</ref> are the causes of most sudden cardiac deaths and account for about 300,000 deaths per year in the united states alone. This figure is most likely underestimated as it doesn't account for deaths due to unwitnessed dysrhythmias.<ref name="pmid21796098">{{cite journal |vauthors=McNally B, Robb R, Mehta M, Vellano K, Valderrama AL, Yoon PW, Sasson C, Crouch A, Perez AB, Merritt R, Kellermann A |title=Out-of-hospital cardiac arrest surveillance --- Cardiac Arrest Registry to Enhance Survival (CARES), United States, October 1, 2005--December 31, 2010 |journal=MMWR Surveill Summ |volume=60 |issue=8 |pages=1–19 |date=July 2011 |pmid=21796098 |doi= |url=}}</ref>
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| ==[[Pulseless ventricular tachycardia risk factors|Risk Factors]]==
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| ==[[Pulseless ventricular tachycardia screening|Screening]]== | | ==[[Pulseless ventricular tachycardia screening|Screening]]== |
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| According to the 2017 American Heart Association guidelines screening of first-degree relatives is recommended when a patient presents with any of the symptoms such as [[Long QT syndrome|QT syndrome]], [[Hypertrophic cardiomyopathy|hypertrophic]] or [[dilated cardiomyopathy]] and right ventricular dysplasia.<ref name="pmid5731530">{{cite journal |vauthors=Shoubkhova TS |title=[Determination of the particle size of suspensions of dried bacteria by the method of turbidimetric analysis] |language=Russian |journal=Zh. Mikrobiol. Epidemiol. Immunobiol. |volume=45 |issue=7 |pages=108–10 |date=July 1968 |pmid=5731530 |doi= |url=}}</ref><ref name="pmid30554599">{{cite journal |vauthors=Flannery MD, La Gerche A |title=Sudden Death and Ventricular Arrhythmias in Athletes: Screening, De-Training and the Role of Catheter Ablation |journal=Heart Lung Circ |volume=28 |issue=1 |pages=155–163 |date=January 2019 |pmid=30554599 |doi=10.1016/j.hlc.2018.10.004 |url=}}</ref>
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| ==[[Pulseless ventricular tachycardia natural history, complications and prognosis|Natural History, Complications, and Prognosis]]== | | ==[[Pulseless ventricular tachycardia natural history, complications and prognosis|Natural History, Complications, and Prognosis]]== |
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| ===Natural History=== | | ==Diagnosis== |
| *On initial presentation, patients with impending [[pulseless ventricular tachycardia]] may present with signs of inadequate [[cardiac perfusion]] such as [[chest pain]], [[shortness of breath]], [[diaphoresis]], [[palpitations]], and [[syncope]].
| | [[Pulseless ventricular tachycardia diagnostic study of choice|Diagnostic Study of Choice]] | [[Pulseless ventricular tachycardia history and symptoms|History and Symptoms]] | [[ Pulseless ventricular_tachycardia_physical_examination|Physical Examination]] | [[Pulseless ventricular tachycardia laboratory findings|Laboratory Findings]] | [[Pulseless ventricular tachycardia electrocardiogram|Electrocardiogram]] | [[Pulseless ventricular tachycardia x ray|X-ray]] | [[Pulseless ventricular tachycardia echocardiography and ultrasound|Echocardiography]] | [[Pulseless ventricular tachycardia MRI|Cardiac MRI]] | [[Pulseless ventricular tachycardia other diagnostic studies|Other Diagnostic Studies]] | |
| *Physical examination may be positive for [[hypotension]], [[tachycardia]], [[tachypnea]], [[increased JVD]], and an [[S1]].
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| *Eventually, Pulseless ventricular tachycardia ensues and patients become unconscious and unresponsive with no detectable pulse.<ref name="pmid32119354">{{cite journal |vauthors=Foglesong A, Mathew D |title= |journal= |volume= |issue= |pages= |date= |pmid=32119354 |doi= |url=}}</ref>
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| ===Complications=== | | ==Treatment == |
| *Common complications of pulseless ventricular tachycardia include<ref name="pmid31723926">{{cite journal |vauthors=Kang Y |title=Management of post-cardiac arrest syndrome |journal=Acute Crit Care |volume=34 |issue=3 |pages=173–178 |date=August 2019 |pmid=31723926 |pmc=6849015 |doi=10.4266/acc.2019.00654 |url=}}</ref><ref name="pmid31200920">{{cite journal |vauthors=Kang JY, Kim YJ, Shin YJ, Huh JW, Hong SB, Kim WY |title=Association Between Time to Defibrillation and Neurologic Outcome in Patients With In-Hospital Cardiac Arrest |journal=Am. J. Med. Sci. |volume=358 |issue=2 |pages=143–148 |date=August 2019 |pmid=31200920 |doi=10.1016/j.amjms.2019.05.003 |url=}}</ref>:
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| **[[Cardiac arrest]]/[[sudden cardiac death]]
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| **[[Anoxic brain injury]] and lifelong neurological complications
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| **[[Post-cardiac arrest syndrome]]
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| **[[Ischemic-reperfusion injury]]
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| **[[Cardiomyopathy]]
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| **Infection related to [[implantable cardioverter-defibrillator]]
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| ===Prognosis===
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| *[[Prognosis]] of pulseless ventricular tachycardia is majorly based on two considerations; the presence of prior expressed or unexpressed cardiac issues, and the time from the beginning of the [[dysrhythmia]] to [[defibrillation]] and conversion to [[sinus rhythm]] and adequate [[perfusion]].<ref name="pmid32119354">{{cite journal |vauthors=Foglesong A, Mathew D |title= |journal= |volume= |issue= |pages= |date= |pmid=32119354 |doi= |url=}}</ref>
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| *Up to 50% of patients who are defibrillated within seconds of the onset of [[tachycardia]] have high survival rates, while patients who experience delays of up to 15 minutes have a survival rate of as low as 5%.<ref name="pmid10699695">{{cite journal |vauthors=Holmberg M, Holmberg S, Herlitz J |title=Incidence, duration and survival of ventricular fibrillation in out-of-hospital cardiac arrest patients in sweden |journal=Resuscitation |volume=44 |issue=1 |pages=7–17 |date=March 2000 |pmid=10699695 |doi=10.1016/s0300-9572(99)00155-0 |url=}}</ref>
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| *While the most significant factors affecting prognosis are underlying structural and ischemic cardiac issues, the presence of other [[comorbidities]] also play a significant role.<ref name="pmid32119354">{{cite journal |vauthors=Foglesong A, Mathew D |title= |journal= |volume= |issue= |pages= |date= |pmid=32119354 |doi= |url=}}</ref>
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| ==Diagnosis==
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| [[Pulseless ventricular tachycardia diagnostic study of choice|Diagnostic study of choice]] | [[Pulseless ventricular tachycardia history and symptoms|History and Symptoms]] | [[Pulseless ventricular tachycardia physical examination|Physical Examination]] | [[Pulseless ventricular tachycardia laboratory findings|Laboratory Findings]] | [[Pulseless ventricular tachycardia electrocardiogram|Electrocardiogram]] | [[Pulseless ventricular tachycardia x ray|X-Ray Findings]] | [[Pulseless ventricular tachycardia echocardiography and ultrasound|Echocardiography and Ultrasound]] | [[Pulseless ventricular tachycardia CT scan|CT-Scan Findings]] | [[Pulseless ventricular tachycardia MRI|MRI Findings]] | [[Pulseless ventricular tachycardia other imaging findings|Other Imaging Findings]] | [[Pulseless ventricular tachycardia other diagnostic studies|Other Diagnostic Studies]]
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| ==Treatment==
| | [[Pulseless ventricular tachycardia medical therapy|Medical Therapy]] | [[Pulseless ventricular tachycardia interventions|Interventions]] | [[Pulseless ventricular tachycardia surgery|Surgery]] | [[Pulseless ventricular tachycardia primary prevention|Primary Prevention]] | [[Pulseless ventricular tachycardia secondary prevention|Secondary Prevention]] |[[Pulseless ventricular tachycardia cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Pulseless ventricular tachycardia future or investigational therapies|Future or Investigational Therapies]] | |
| [[Pulseless ventricular tachycardia medical therapy|Medical Therapy]] | [[Pulseless ventricular tachycardia interventions|Interventions]] | [[Pulseless ventricular tachycardia surgery|Surgery]] | [[Pulseless ventricular tachycardia primary prevention|Primary Prevention]] | [[Pulseless ventricular tachycardia secondary prevention|Secondary Prevention]] | [[Pulseless ventricular tachycardia cost-effectiveness of therapy|Cost-Effectiveness of Therapy]] | [[Pulseless ventricular tachycardia future or investigational therapies|Future or Investigational Therapies]] | |
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| ==Case Studies== | | ==Case Studies== |
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| {{WH}} | | {{WH}} |
| {{WS}} | | {{WS}} |
| | <references /> |
