Ivabradine in treatment of sinus tachycardia mediated vasovagal syncope.

Aims: Ivabradine, an I(f) current blocker, has shown promising results in treatment of postural orthostatic tachycardia syndrome (POTS). There is a subgroup of vasovagal syncope (VVS) patients, who demonstrate sinus tachycardia before collapse on tilt testing mimicking some features of POTS. These patients may also respond to ivabradine therapy.

Blood pressure oscillations during tilt testing as a predictive marker of vasovagal syncope.

Aims: During head-up tilt (HUT) testing, a period of haemodynamic instability, marked by oscillations in blood pressure, often precedes vasovagal syncope. We hypothesized that the presence of oscillations in blood pressure during HUT testing predicts a positive diagnosis for vasovagal syncope.

Methods And Results: The haemodynamic profiles of 42 consecutive patients non-responsive to passive HUT and glyceryl trinitrate (GTN) provocation ('non-responders') and, contemporaneously, 41 consecutive patients responsive to passive HUT and GTN provocation ('responders') were assigned oscillation-positive or oscillation-negative depending on the presence or absence of a characteristic oscillation in systolic blood pressure which varied by > or =30 mmHg (peak-to-trough).