| 1. |
- Bachus, E, et al.
(författare)
-
Monitoring of cerebral oximetry during head-up tilt test in adults with history of syncope and orthostatic intolerance
- 2018
-
Ingår i: Europace. - : Oxford University Press (OUP). - 1532-2092.
-
Tidskriftsartikel (refereegranskat)abstract
- Aims: We applied near-infrared-spectroscopy (NIRS) to measure absolute frontal cerebral tissue oxygen saturation (SctO2) during head-up tilt test (HUT) in patients investigated for unexplained syncope.Methods and results: Synchronized non-invasive beat-to-beat haemodynamic monitoring, ECG, SctO2 (NIRS; normal range: 60-80%), and peripheral oxygen saturation (left hand, SpO2) were applied during HUT in a random sample of patients with unexplained syncope. Tracings of 54 patients (mean-age: 55 ± 19 years, 39% male) with negative HUT, vasovagal syncope (VVS), or orthostatic hypotension (OH) were analysed. In 44 patients HUT was diagnostic, in 10 HUT was negative. Thirty-one experienced VVS. Of these, 6 had spontaneous and 25 nitroglycerin-induced syncope. Thirteen patients had orthostatic hypotension (OH). Although there was no significant change in mean-arterial pressure from baseline to 1 min before syncope or end of passive HUT phase (-1.4 ± 13.9 mmHg; P = 0.45), there was a significant fall in SctO2 during the same period (-3.2 ± 3.2%; P ≤ 0.001). Among patients who experienced syncope, a decrease in SctO2 from 71 ± 5% at baseline to 53 ± 9% (P < 0.001) at syncope was observed. During HUT, there was a significant difference in delta SctO2 between spontaneous VVS (-4.5 ± 3.0%) and negative HUT (-1.3 ± 1.9%; P = 0.021), but not between spontaneous VVS and OH (-5.4 ± 4.2%; P = 0.65). In spontaneous VVS, progressive decrease of SctO2 was independent of mean arterial pressure decrease (P = 0.22).Conclusions: Progressive decrease in cerebral tissue oxygenation independent of mean-arterial pressure may precede spontaneous vasovagal reflex during tilt. Patients experience syncope when SctO2 falls below 60%. These data confirm clinical utility of absolute cerebral oximetry monitoring for syncope investigation. We applied NIRS to measure frontal cerebral tissue oxygen saturation (SctO2) during head-up tilt test (HUT) in patients with unexplained syncope. In 44 of 54 patients, HUT was diagnostic. In patients with syncope, a significant SctO2-decrease was observed. Different patterns of SctO2 can be detected.
|
|
| 2. |
|
|
| 3. |
- Engstrom, G., et al.
(författare)
-
Cardiovagal Function Measured by the Deep Breathing Test: Relationships With Coronary Atherosclerosis
- 2022
-
Ingår i: Journal of the American Heart Association. - : Ovid Technologies (Wolters Kluwer Health). - 2047-9980. ; 11:7
-
Tidskriftsartikel (refereegranskat)abstract
- Background The cardiovagal function can be assessed by quantification of respiratory sinus arrhythmia (RSA) during a deep breathing test. However, population studies of RSA and coronary atherosclerosis are lacking. This population-based study examined the relationship between RSA during deep breathing and coronary atherosclerosis, assessed by coronary artery calcium score (CACS). Methods and Results SCAPIS (Swedish Cardiopulmonary Bioimage Study) randomly invited men and women aged 50 to 64 years from the general population. CACS was obtained from computed tomography scanning, and deep breathing tests were performed in 4654 individuals. Expiration-inspiration differences (E-Is) of heart rates were calculated, and reduced RSA was defined as E-I in the lowest decile of the population. The relationship between reduced RSA and CACS (CACS >= 100 or CACS >= 300) was calculated using multivariable-adjusted logistic regression. The proportion of CACS >= 100 was 24% in the lowest decile of E-I and 12% in individuals with E-I above the lowest decile (P<0.001), and the proportion of CACS >= 300 was 12% and 4.8%, respectively (P<0.001). The adjusted odds ratio (OR) for CACS >= 100 was 1.42 (95% CI, 1.10-1.84) and the adjusted OR for CACS >= 300 was 1.62 (95% CI, 1.15-2.28), when comparing the lowest E-I decile with deciles 2 to 10. Adjusted ORs per 1 SD lower E-I were 1.17 (P=0.001) for CACS >= 100 and 1.28 (P=0.001) for CACS >= 300. Conclusions Low RSA during deep breathing is associated with increased coronary atherosclerosis as assessed by CACS, independently of traditional cardiovascular risk factors. Cardiovagal dysfunction could be a prevalent and modifiable risk factor for coronary atherosclerosis in the general population.
|
|
| 4. |
|
|
| 5. |
|
|
