Pulsus alternans: Difference between revisions

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{{CMG}}; {{AE}} [[Varun Kumar]], M.B.B.S.
{{CMG}}; {{AE}} [[Varun Kumar]], M.B.B.S.; {{MM}}


==Overview==
==Overview==
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==Pathophysiology==
==Pathophysiology==
In left ventricular dysfunction, the [[ejection fraction]] will decrease significantly, causing reduction in [[stroke volume]], hence causing a increase in [[end-diastolic volume]]. There may initially be a tachycardia as a compensatory mechanism to try to keep the cardiac output constant. As a result, during the next cycle of systolic phase, the [[myocardium|myocardial muscle]] will be stretched more than usual and as a result cause an increase in myocardial contraction, related to the [[Frank-Starling's law|Frank–Starling]] physiology of the heart. This in turn results in a stronger systolic pulse.
The mechanism of pulsus alternans was referred to Starling's law of the heart.<ref name="pmid13899176">{{cite journal| author=GLEASON WL, BRAUNWALD E| title=Studies on Starling's law of the heart. VI. Relationships between left ventricular enddiatolic volume and stroke volume in man with observations on the mechanism of pulsus alternans. | journal=Circulation | year= 1962 | volume= 25 | issue=  | pages= 841-8 | pmid=13899176 | doi= | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=13899176  }} </ref>  The [[ejection fraction]] will decrease significantly in cases of left ventricular dysfunction, which is the most important cause of pulsus alternans, causing reduction in [[stroke volume]], and this reduction results in an increase in the [[end-diastolic volume]]. As explained by Starling's law, during the next cycle of systolic phase, the [[myocardium|myocardial muscle]] will be stretched more than usual and causes an increase in myocardial contraction, this in turn results in a stronger systolic pulse.


[[Image:Pulsus_alternans_trace.jpg|center|400px]]
[[Image:Pulsus_alternans_trace.jpg|center|400px]]


==Causes==
==Causes==
===Overview===
The presence of pulsus alternans almost indicate severe [[left ventricular failure]], and patients should undergo further investigations for proper management.


===Life Threatening Causes===
===Life Threatening Causes===
Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated. Pulsus alternans in itself is not a life threatening condition, but in most of cases it indicate sever [[left ventricular failure]] and further investigations should be done.


===Common Causes===
===Common Causes===
The most common cause of pulsus alternans is [[Left ventricular failure]], other causes include:
*[[Asthma]]
*[[Cardiac tamponade]]
*[[Peripartum cardiomyopathy|Meadows syndrome]]
*[[Premature ventricular contraction]]
*[[Aortic insufficiency|Severe aortic regurgitation]]


=== Causes by Organ System ===
=== Causes by Organ System ===
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{|style="width:70%; height:100px" border="1"
{|style="width:70%; height:100px" border="1"
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:25%" border="1" bgcolor="LightSteelBlue" | '''Cardiovascular'''
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | No underlying causes
|style="height:100px"; style="width:75%" border="1" bgcolor="Beige" | [[Cardiac tamponade]], [[Peripartum cardiomyopathy|Meadows syndrome]], [[premature ventricular contraction]], [[Aortic insufficiency|severe aortic regurgitation]]
|-
|-
|-bgcolor="LightSteelBlue"
|-bgcolor="LightSteelBlue"
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|-bgcolor="LightSteelBlue"
|-bgcolor="LightSteelBlue"
| '''Musculoskeletal / Ortho'''
| '''Musculoskeletal / Ortho'''
|bgcolor="Beige"| [[Scoliosis|Idiopathic spinal scoliosis]]
|bgcolor="Beige"| No underlying causes
|-
|-
|-bgcolor="LightSteelBlue"
|-bgcolor="LightSteelBlue"
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|-bgcolor="LightSteelBlue"
|-bgcolor="LightSteelBlue"
| '''Overdose / Toxicity'''
| '''Overdose / Toxicity'''
|bgcolor="Beige"| [[Diethylpropion]], monocrotaline,<ref name="pmid9776954">{{cite journal| author=Schultze AE, Roth RA| title=Chronic pulmonary hypertension--the monocrotaline model and involvement of the hemostatic system. | journal=J Toxicol Environ Health B Crit Rev | year= 1998 | volume= 1 | issue= 4 | pages= 271-346 | pmid=9776954 | doi=10.1080/10937409809524557 | pmc= | url=http://www.ncbi.nlm.nih.gov/entrez/eutils/elink.fcgi?dbfrom=pubmed&tool=sumsearch.org/cite&retmode=ref&cmd=prlinks&id=9776954 }} </ref> [[phentermine]], [[radiation exposure]] ([[fibrosing mediastinitis]] and [[pulmonary fibrosis]]).
|bgcolor="Beige"| [No underlying causes
|-
|-
|-bgcolor="LightSteelBlue"
|-bgcolor="LightSteelBlue"
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|-bgcolor="LightSteelBlue"
|-bgcolor="LightSteelBlue"
| '''Pulmonary'''
| '''Pulmonary'''
|bgcolor="Beige"| No underlying causes
|bgcolor="Beige"| [[Asthma]]
|-
|-
|-bgcolor="LightSteelBlue"
|-bgcolor="LightSteelBlue"
| '''Renal / Electrolyte'''
| '''Renal / Electrolyte'''
|bgcolor="Beige"| [[renal failure|Chronic renal failure]] on [[dialysis]]
|bgcolor="Beige"| No underlying causes
|-
|-
|-bgcolor="LightSteelBlue"
|-bgcolor="LightSteelBlue"
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|-bgcolor="LightSteelBlue"
|-bgcolor="LightSteelBlue"
| '''Miscellaneous'''
| '''Miscellaneous'''
|bgcolor="Beige"| [[Gaucher disease]], [[glycogen storage diseases]], [[Scoliosis|idiopathic spinal scoliosis]],
|bgcolor="Beige"| No underlying causes
|-
|-
|}
|}
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=== Causes in Alphabetical Order ===
=== Causes in Alphabetical Order ===


*[[Asthma]]


*[[Cardiac tamponade]]


==Related Chapters==
*[[Left ventricular failure]]
[[Congestive cardiac failure]]


*[[Peripartum cardiomyopathy|Meadows syndrome]]
*[[Premature ventricular contraction]]
*[[Aortic insufficiency|Severe aortic regurgitation]]


==References==
==References==
{{Reflist|2}}
{{Reflist|2}}
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[[Category:Cardiology]]
[[Category:Cardiology]]
[[Category:Disease]]
[[Category:Disease]]
[[Category:Mature chapter]]
[[Category:Mature chapter]]
[[Category:Medical signs]]
[[Category:Signs and symptoms]]
[[Category:Signs and symptoms]]
[[Category:Physical examination]]
[[Category:Physical examination]]
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{{Circulatory system pathology}}
{{Circulatory system pathology}}


 
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Latest revision as of 18:26, 12 June 2015


Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Varun Kumar, M.B.B.S.; Mohamed Moubarak, M.D. [2]

Overview

Pulsus alternans is a physical finding with arterial pulse waveform showing alternating strong and weak beats.[1] It is almost always indicative of left ventricular systolic impairment, and carries a poor prognosis.

Pathophysiology

The mechanism of pulsus alternans was referred to Starling's law of the heart.[2] The ejection fraction will decrease significantly in cases of left ventricular dysfunction, which is the most important cause of pulsus alternans, causing reduction in stroke volume, and this reduction results in an increase in the end-diastolic volume. As explained by Starling's law, during the next cycle of systolic phase, the myocardial muscle will be stretched more than usual and causes an increase in myocardial contraction, this in turn results in a stronger systolic pulse.

Causes

Overview

The presence of pulsus alternans almost indicate severe left ventricular failure, and patients should undergo further investigations for proper management.

Life Threatening Causes

Life-threatening causes include conditions which may result in death or permanent disability within 24 hours if left untreated. Pulsus alternans in itself is not a life threatening condition, but in most of cases it indicate sever left ventricular failure and further investigations should be done.

Common Causes

The most common cause of pulsus alternans is Left ventricular failure, other causes include:

Causes by Organ System

Cardiovascular Cardiac tamponade, Meadows syndrome, premature ventricular contraction, severe aortic regurgitation
Chemical / poisoning No underlying causes
Dermatologic No underlying causes
Drug and Toxin Side Effect No underlying causes
Ear Nose Throat No underlying causes
Endocrine No underlying causes
Environmental No underlying causes
Gastroenterologic No underlying causes
Genetic [No underlying causes
Hematologic No underlying causes
Iatrogenic No underlying cause
Infectious Disease No underlying causes
Musculoskeletal / Ortho No underlying causes
Neurologic No underlying cause
Nutritional / Metabolic No underlying cause
Obstetric/Gynecologic No underlying cause
Oncologic No underlying causes
Opthalmologic No underlying causes
Overdose / Toxicity [No underlying causes
Psychiatric No underlying causes
Pulmonary Asthma
Renal / Electrolyte No underlying causes
Rheum / Immune / Allergy No underlying causes
Sexual No underlying causes
Trauma No underlying causes
Urologic No underlying causes
Miscellaneous No underlying causes

Causes in Alphabetical Order

References

  1. ↑ Euler D (1999) Cardiac alternans: mechanisms and pathophysiological significance. Cardiovascular Research. Vol. 42. P. 583-590. PMID 10533597
  2. ↑ GLEASON WL, BRAUNWALD E (1962). "Studies on Starling's law of the heart. VI. Relationships between left ventricular enddiatolic volume and stroke volume in man with observations on the mechanism of pulsus alternans". Circulation. 25: 841–8. PMID 13899176.


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