Successful treatment of
cough syncope depends on the correction of various pathogenetic mechanisms among different patients. The valsalva maneuver (VM), which elicits hemodynamic responses mimicking
coughs, has potential for investigating the individual pathogenesis of
cough syncope. Eighteen consecutive patients suffering from
cough-induced
syncope were examined. All patients were asked to
cough and to perform VM several times under continuous cerebral blood-flow velocity and blood pressure (BP) monitoring by transcranial Doppler and finger plethysmography. Eight patients demonstrated abnormal VM characterized by the absent BP overshoot following the relief of straining. Patients demonstrating abnormal VM had delayed BP recovery after
cough (median, 16.4; range, 8.7-25.6 seconds) compared to those demonstrating normal VM (2.6, 1.3-3.8 seconds, p < 0.001). Seven of the 10 patients exhibiting normal BP overshoot during VM had stenotic arterial lesions in the cerebral or coronary circulation, whereas only one of the eight patients demonstrating absent BP overshoot had
coronary artery disease (70% vs. 12.5%, p = 0.025). Other clinical profiles, body mass index, frequency of
obstructive pulmonary disease and valsalva ratio did not differ between patients featuring normal and absent BP overshoot. In conclusion, the pathogenesis of
cough syncope could be different between patients with normal and abnormal VM responses. Patients who had
no BP overshoot during VM sustained prolonged
hypotension after
cough. The VM helps in discriminating among pathogenic mechanisms and guiding investigation and treatment for
cough syncope patients.