Cardiac Causes of Syncope

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Cardiac Causes of Syncope - #20

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Review cardiac causes of syncope.

Assessment

Cardiac causes of syncope:

  • Cardiac arrhythmias: Sinus node disease, AV block, VT; diagnosable with ECG
  • Orthostatic hypotension: evaluate with standing BP measurements
  • Carotid Sinus syndrome: due to hypersensitivity of carotid sinus; diagnosable with 3+ seconds of asystole upon carotid massage
  • Vasovagal faint: hypotension /bradycardia usually with an identifiable cause in patient’s history (e.g. standing for long periods of time)
  • Postprandial hypotension
  • Structural Cardiac Disease: valvular disease, acute MI, obstructive cardiomyopathy

Click and Enlarge Image 1 Below: Diagnostic Steps to Determine the Cause of Syncope4

Image 1

Context

Geriatric Patient in hospital.

Action

Elderly patient that presents to the hospital with syncope.

Definition

A transient, self-limited loss of consciousness, usually leading to falling and secondary to a temporary reduction of blood flow to parts of the brain responsible for consciousness.1

Incidence / Prevalence

Syncope is the seventh most common reason for emergency admission of patients over 65 years of age. A retrospective analysis of syncope in 711 very old (mean age 87 years) institutionalized patients revealed a 10 year prevalence of 23 % and one year incidence of 7 %. A two-year prospective follow-up of this population revealed a yearly incidence of 6% and recurrence rate of 30 %2. Despite the fact that in up to 40% of patients with syncope no etiology is found, in some studies, cardiac pathology accounts for approximately 10-20% of syncope in the older adult2 and is associated with higher mortality rates irrespective of age.3

Underlying Sciences

The temporary cessation of cerebral function that causes syncope results from transient and sudden reduction of blood flow to parts of the brain (brain stem reticular activating system) responsible for consciousness.4 Age-related physiologic changes that may participate in the increase incidence of syncope in the older adult: (1) blunted baroreflex sensibility (impaired ability to maintain cerebral blood flow in the setting of hypotension by increasing heart rate and vascular tone). (2) Reduced blood volume due to impaired renal ability to conserve sodium, decline in plasma rennin and aldosterone, and increase in atrial natriuretic peptide (increased susceptibility to orthostatic hypotension). (3) Decreased heart ventricles elasticity and increased after-load (gradual diastolic dysfunction and decrease cardiac output).1

Science Principles

Immunosenescense
Impaired homeostasis
Post-mitotic tissue and age related degeneration

Objectives

  1. List the cardiac causes of syncope in the elderly.
  2. Outline the steps needed to determine the cause of syncope.

Keywords/Tags

References

Hazzard’s geriatric medicine and gerontology. New York, NY: McGraw-Hill Medical, 2009.
Lipsitz LA, Wei JY, Rowe JW. Syncope in an elderly, institutionalized population: prevalence, incidence, and associated risk. Q J Med. 1985 Apr;55(216):45-54. http://www.ncbi.nlm.nih.gov/pubmed/?term=syncope+in+elderly+institutionalized+population+prevalence+incidence+and+associated+risk
Soteriades ES, Evans JC, Larson MG, Chen MH, Chen L, Benjamin EJ, Levy D. Incidence and prognosis of syncope. N Engl J Med. 2002 19;347(12):878-85. http://www.ncbi.nlm.nih.gov/pubmed/?term=incidence+and+prognosis+of+syncope+soteriades
Brocklehurst's textbook of geriatric medicine and gerontology. Edited by Howard M Fillit, Kenneth Rockwood, Kenneth Woodhouse.  Philadelphia, PA: Saunders/Elsevier,  7th Edition.  2010.

This GFF ___ my competence in geriatrics.

Authors

Nicholas Dreger, Kathryn Denson MD, Gabriel Manzi MD, Bambi Wessel

Author Affiliation

Medical College of Wisconsin, Milwaukee, Wisconsin

Copyright

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