Cough Syncope

Timothy C. Hain, MD Page last modified: December 25, 2011
Cough Syncope defined Causes Evaluation Index

Cough syncope is a syndrome in which dizziness or syncope occurs after prolonged bouts of cough. See also the syncope page, if symptoms are not particular associated with a cough.

Cause of cough syncope:

Normal or exaggerated response to forceful cough.
Abnormally sensitive cardio-depressor response to Valvalva (straining)
Chiari Malformation

Cough syncope patients not exhibit more pronounced hypotension in response to cough than other fainters, but they also manifest an inappropriate cough-triggered blood pressure-heart rate relationship. These findings argue in favor of the importance of a neurally mediated reflex contribution to symptomatic hypotension in cough syncope. (Benditt, D. G., N. Samniah, et al.; 2005).

It is well known that cough syncope may occur in the Arnold-Chiari malformation (Ireland, P. D., D. Mickelsen, et al. (1996)). This is probably due to impaired autonomic regulation.

Evaluation of cough syncope:

Physical examination should include at a minimum

blood pressure and pulse, standing and supine
cardiac exam
Carotid sinus testing
Check pulse and ideally blood pressure during Valsalva and coughing.

Routine Laboratory Testing:

ECG
Autonomic testing, including tilt-table testing
- The tilt table test should include a valsalva and coughing to simulate the situation.
MRI (for Chiari malformation)
24 hour holter (for sick-sinus).
EEG -- should be normal. It may be helpful to exclude seizures. (Gelisse, P. and P. Genton (2008)_

According to Chao, A. C., R. T. Lin, et al. (2007). Cough syncope patients often exhibit absent BP overshoot following the relief of straining.

According to Choi, Y. S., J. J. Kim, et al. (1989). Sinus arrest may play a role as a mechanism of cough syncope in a patient with sick sinus syndrome, and 24 hour holter monitoring may be helpful in making this diagnosis.

Treatment

Most effort is aimed at treating the cough with cough suppressants, and exhaling before coughing.

If the patient has an central or peripheral dysautonomia, treatment should be directed towards correcting that disorder too.

References:

Benditt, D. G., N. Samniah, et al. (2005). "Effect of cough on heart rate and blood pressure in patients with "cough syncope"." Heart Rhythm 2(8): 807-13.
Chao, A. C., R. T. Lin, et al. (2007). "Mechanisms of cough syncope as evaluated by valsalva maneuver." Kaohsiung J Med Sci 23(2): 55-62.
Choi, Y. S., J. J. Kim, et al. (1989). "Cough syncope caused by sinus arrest in a patient with sick sinus syndrome." Pacing Clin Electrophysiol 12(6): 883-6.
Dhar, R., R. J. Duke, et al. (2003). "Cough syncope from constrictive pericarditis: a case report." Can J Cardiol 19(3): 295-6.
Gelisse, P. and P. Genton (2008). "Cough syncope misinterpreted as epileptic seizure." Epileptic Disord 10(3): 223-4.
Ireland, P. D., D. Mickelsen, et al. (1996). "Evaluation of the autonomic cardiovascular response in Arnold-Chiari deformities and cough syncope syndrome." Arch Neurol 53(6): 526-31.
Mattle, H. P., A. C. Nirkko, et al. (1995). "Transient cerebral circulatory arrest coincides with fainting in cough syncope." Neurology 45(3 Pt 1): 498-501.

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