#020 Cardiac Causes of Syncope in Geriatric Patients

Fast Facts and Concepts #020 PDF

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

Objectives:

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

Context: Geriatric Patient in hospital.

Action: Elderly patient that presents to the hospital with syncope.

ACGME Competencies: Patient Care, Medical Knowledge, Practice Based learning and improving.

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

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

Diagnostic Steps to Determine the Cause of Syncope⁴

Underlying Science: 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

References:

1. Hazzard’s geriatric medicine and gerontology. New York, NY: McGraw-Hill Medical, 2009.
2. 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.
3. 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.
4. Brocklehurst's textbook of geriatric medicine and gerontology. Edited by Howard M Fillit, Kenneth Rockwood, Kenneth Woodhouse.  Philadelphia, PA: Saunders/Elsevier,  7^th Edition.  2010.

Author Affiliation: Medical College of Wisconsin, Milwaukee, Wisconsin.

Geriatric Fast Facts are edited by the faculty of the Geriatric Education Teams (GETS) program funded by the Reynolds Foundation, Kathryn Denson, MD, Steven Denson, MD, & Edmund Duthie, MD from the Division of Geriatrics, Medical College of Wisconsin, and are published by the Geriatric Fast Facts Website at the Medical College of Wisconsin. For more information write Kathryn Denson, MD. More information, as well as the complete set of Fast Facts, available at www.mcw.edu/Geriatric-Fast-Facts.htm

Copyright/Referencing Information: Users are free to download and distribute Geriatric Fast Facts for educational purposes only. Citation: Nicholas Dreger, Kathryn Denson MD, Gabriel Manzi MD, Bambi Wessel, Fast Fact #20: Cardiac Causes of Syncope in Geriatric Patients, September, 2012.

Geriatric Fast Facts, available at www.mcw.edu/Geriatric-Fast-Facts.htm

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