Table 3.

Frequencies of cough syncope/pre-syncope in four groups of subjects classified by the presence of both-side JVR and the levels of plasma ET-1

Both-side JVR	Plasma ET-1, pg/ml	Cough syncope/pre-syncope		pvalue
		-	+
No	≦ 3.43	38 (92.7%)	3 (7.3%)	<0.001
Yes	≦ 3.43	8 (61.5%)	5 (38.5%)
No	> 3.43	5 (55.6%)	4 (44.4%)
Yes	> 3.43	0	5 (100%)

Presented as numbers (%). Abbreviations: JVR = jugular venous reflux; ET-1 = endothelin-1.