Pulsus alternans
Editor-In-Chief: C. Michael Gibson, M.S., M.D. [1]; Associate Editor(s)-in-Chief: Varun Kumar, M.B.B.S.
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
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 myocardial muscle will be stretched more than usual and as a result cause an increase in myocardial contraction, related to the Frank–Starling physiology of the heart. This in turn results in a stronger systolic pulse.
Causes
Life Threatening Causes
Common Causes
Causes by Organ System
| Cardiovascular | No underlying causes |
| 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 | Idiopathic spinal scoliosis |
| Neurologic | No underlying cause |
| Nutritional / Metabolic | No underlying cause |
| Obstetric/Gynecologic | No underlying cause |
| Oncologic | No underlying causes |
| Opthalmologic | No underlying causes |
| Overdose / Toxicity | Diethylpropion, monocrotaline,[2] phentermine, radiation exposure (fibrosing mediastinitis and pulmonary fibrosis). |
| Psychiatric | No underlying causes |
| Pulmonary | No underlying causes |
| Renal / Electrolyte | Chronic renal failure on dialysis |
| Rheum / Immune / Allergy | No underlying causes |
| Sexual | No underlying causes |
| Trauma | No underlying causes |
| Urologic | No underlying causes |
| Miscellaneous | Gaucher disease, glycogen storage diseases, idiopathic spinal scoliosis, |
Causes in Alphabetical Order
Related Chapters
References
- ↑ Euler D (1999) Cardiac alternans: mechanisms and pathophysiological significance. Cardiovascular Research. Vol. 42. P. 583-590. PMID 10533597
- ↑ Schultze AE, Roth RA (1998). "Chronic pulmonary hypertension--the monocrotaline model and involvement of the hemostatic system". J Toxicol Environ Health B Crit Rev. 1 (4): 271–346. doi:10.1080/10937409809524557. PMID 9776954.