Hemodynamic mechanisms underlying prolonged post-faint hypotension

During hypotension induced by tilt-table testing, low presyncopal blood pressure (BP) usually recovers within 1 min after tilt back. However, in some patients prolonged post faint hypotension (PPFH) is observed. We assessed the hemodynamics underlying PPFH in a retrospective study. Seven patients (2 females, aged 31-72 years) experiencing PPFH were studied. PPFH was defined as a systolic BP below 85 mmHg for at least 2 min after tilt back. In 6 out of 7 presyncope was provoked by 0.4 mg sublingual NTG, administered in the 60° head-up tilt position following head-up tilt for 20 min. Continuous BP was monitored and stroke volume (SV) was computed from pressure pulsations. Cardiac output (CO) was calculated from SV × heart rate (HR); and total peripheral resistance (TPR) from mean BP/CO. Left ventricular contractility was estimated by dP/dt (max) of finger pressure pulse. Systolic BP (SYS), diastolic BP (DIAS) and HR during PPFH were lower compared to baseline: SYS 75 ± 14 versus 121 ± 18 mmHg, DIAS 49 ± 9 versus 71 ± 9 mmHg and HR 52 ± 14 versus 67 ± 12 beats/min (p < 0.05). Marked hypotension was associated with a 47% fall in CO 3.1 ± 0.6 versus 5.9 ± 1.3 L/min (p < 0.05) and decreases in dP/dt, 277 ± 77 versus 759 ± 160 mmHg/s (p < 0.05). The difference in TPR was not significant 1.1 ± 0.3 versus 1.0 ± 0.3 MU (p = 0.229). In four patients, we attempted to treat PPFH by 30° head-down tilt. This intervention increased SYS only slightly (to 89 ± 12 mmHg). PPFH seems to be mediated by severe cardiac depressio

Management of initial orthostatic hypotension: lower body muscle tensing attenuates the transient arterial blood pressure decrease upon standing from squatting

A B S T R A C T IOH (initial orthostatic hypotension) comprises symptoms of cerebral hypoperfusion caused by an abnormally large transient MAP (mean arterial pressure) decrease 5-15 s after arising from a supine, sitting or squatting position. Few treatment options are available. In the present study, we set out to test the hypothesis that LBMT (lower body muscle tensing) attenuates IOH after rising from squatting and its symptoms in daily life. A total of 13 IOH patients (nine men; median age, 27 years) rose from squatting twice, once with LBMT and once without. In addition, seven healthy volunteers (five men; median age, 27 years) were studied in a cross-over study design. They stood up from the squatting position three times, once combined with LBMT. Blood pressure (Finometer) was measured continuously, and CO (cardiac output) by Modelflow and TPR (total peripheral resistance) were computed. MAP, CO and TPR were compared without and with LBMT. Using a questionnaire, the perceived effectiveness of LBMT in the patients&apos; daily lives was evaluated. With LBMT, the minimal MAP after standing up was higher in both groups (19 mmHg in patients and 13 mmHg in healthy subjects). In healthy subjects, the underlying mechanism was a blunted TPR decrease (to 47 % compared with 60 %; P &lt; 0.05), whereas in the patients no clear CO or TPR pattern was discernible. During follow-up, eight out of ten patients using LBMT reported fewer IOH symptoms. In conclusion, LBMT is a new intervention to attenuate the transient blood pressure decrease after standing up from squatting, and IOH patients should be advised about the use of this manoeuvre

Optimizing squatting as a physical maneuver to prevent vasovagal syncope

OBJECTIVES: Squatting is a potent physical maneuver to prevent syncope; however, a major drawback is that standing up from squatting is a large hemodynamic stressor that often causes new presyncopal symptoms. We tested the hypothesis that lower body skeletal muscle tensing (LBMT) attenuates the decrease of mean arterial blood pressure (MAP) upon standing from squatting when used as a maneuver to prevent vasovagal syncope. METHODS AND RESULTS: In 18 patients (10 females and 8 males, median age 37.5 years) we followed continuous MAP, cardiac output (CO, by Modelflow) and total peripheral resistance (TPR) during tilt test-provoked pre-syncopal episodes. After standing up from squatting MAP decreased to a nadir of 64 +/- 4 mmHg (mean +/- SE), related to a reduction in CO 73 +/- 5% of supine values. Standing up with LBMT limited the reduction in CO (85 +/- 6 %, P < 0.05) and MAP nadir (to 76 +/- 3 mmHg; P < 0.05 compared to without LBMT) with fewer or no presyncopal symptoms. Standing up from squatting with and without LBMT did not affect TPR (99 +/- 5% vs. 101 +/- 7%). INTERPRETATION: LBMT is proposed as an effective follow-up maneuver to squatting when applied to prevent syncop

Effectiveness of midodrine treatment in patients with recurrent vasovagal syncope not responding to non-pharmacological treatment (STAND-trial)

Initial treatment of vasovagal syncope (VVS) consists of advising adequate fluid and salt intake, regular exercise, and physical counterpressure manoeuvres. Despite this treatment, up to 30% of patients continue to experience regular episodes of VVS. We investigated whether additional Midodrine treatment is effective in these patients. In our study, patients with at least three syncopal and/or severe pre-syncopal recurrences during non-pharmacological treatment were eligible to receive double-blind cross-over treatment starting either with Midodrine or placebo. Treatment periods lasted for 3 months with a wash-out period of 1 week in-between. At baseline and after each treatment period, we collected data about the recurrence of syncope and pre-syncope, side effects, and quality of life (QoL). Twenty-three patients (17% male, mean age 32) included in the cross-over trial received both Midodrine and placebo treatment. The proportion of patients who experienced syncopal and pre-syncopal recurrences did not differ significantly between Midodrine and placebo treatment (syncope: 48 vs. 65%, P= 0.22; pre-syncope: 74 vs. 78%, P> 0.99). The median number of syncopes and pre-syncopes per 3 months were also not significantly different during Midodrine and placebo treatment (0 vs. 1; P= 0.57; and 6 vs. 8; P= 0.90). The occurrence of side effects was similar during Midodrine and placebo treatment (48 vs. 57%; P= 0.75). Also, QoL did not differ significantly. Our findings indicate that additional Midodrine treatment is less effective in patients with VVS not responding to non-pharmacological treatment than reported as first-line treatmen

Association between psychological complaints and recurrence of vasovagal syncope

Vasovagal syncope (VVS), the most common cause of transient loss of consciousness (T-LOC), is often accompanied by higher levels of psychological distress. We investigated to what extent psychological complaints interact with the effects of non-pharmacological treatment in patients with frequently recurring VVS. Patients with ≥3 episodes of VVS in the 2 years prior to the start of the study openly received non-pharmacological treatment. Before treatment initiation, we determined the level of general psychological complaints by the Symptom Checklist 90-R (SCL-90-R) questionnaire. We regularly evaluated syncopal recurrence during follow-up. We compared the SCL-90-R scores of VVS patients in our study with the corresponding scores of healthy Dutch subjects (reference population). We examined whether patients with more recurrences during follow-up had higher SCL-90-R scores at baseline and whether this association changed when adjusting for other factors associated with recurrence using logistic regression. Total SCL-90-R scores were higher in our cohort of patients with frequent episodes of VVS than in the reference population (142 vs. 118; p < 0.001). During the first 6 months of treatment, 42% of patients experienced syncopal recurrence(s). The SCL-90-R scores of these patients were significantly higher compared with patients without syncopal recurrence in this period (160 vs. 130; p = 0.01). After adjusting for other predictors of recurrence, especially the number of episodes before inclusion, the association between SCL-90-R scores and recurrence remained intact. Levels of general psychological complaints are higher in patients with syncopal recurrence during non-pharmacological treatment of VVS, even after adjusting for previous syncopal episode

Management of initial orthostatic hypotension: lower body muscle tensing attenuates the transient arterial blood pressure decrease upon standing from squatting

IOH (initial orthostatic hypotension) comprises symptoms of cerebral hypoperfusion caused by an abnormally large transient MAP (mean arterial pressure) decrease 5-15 s after arising from a supine, sitting or squatting position. Few treatment options are available. In the present study, we set out to test the hypothesis that LBMT (lower body muscle tensing) attenuates IOH after rising from squatting and its symptoms in daily life. A total of 13 IOH patients (nine men; median age, 27 years) rose from squatting twice, once with LBMT and once without. In addition, seven healthy volunteers (five men; median age, 27 years) were studied in a cross-over study design. They stood up from the squatting position three times, once combined with LBMT. Blood pressure (Finometer) was measured continuously, and CO (cardiac output) by Modelflow and TPR (total peripheral resistance) were computed. MAP, CO and TPR were compared without and with LBMT Using a questionnaire, the perceived effectiveness of LBMT in the patients' daily lives was evaluated. With LBMT, the minimal MAP after standing up was higher in both groups (19 mmHg in patients and 13 mmHg in healthy subjects). In healthy subjects, the underlying mechanism was a blunted TPR decrease (to 47% compared with 60%; P <0.05), whereas in the patients no clear CO or TPR pattern was discernible. During follow-up, eight out of ten patients using LBMT reported fewer IOH symptoms. In conclusion, LBMT is a new intervention to attenuate the transient blood pressure decrease after standing up from squatting, and IOH patients should be advised about the use of this mancieuvr