We describe the capnography tilt test (CTT) for the diagnosis of hyperventilation syncope. The CTT is a 10-min supine, 30-min head-up tilt test with simultaneous monitoring of end-tidal PCO2 (ETPCO2). Hyperventilation (HV) was defined as ETPCO2 < or = 25 mmHg. Hyperventilation syncope (HV syncope) was defined as loss of consciousness with ETPCO2 < or = 25 mmHg and no significant drop in blood pressure. Four groups of patients had the CTT: group I (n = 14), patients presenting with syncope who during a prior tilt test had lost consciousness without concomitant fall in blood pressure; group II (n = 50), syncope, primary evaluation, no prior tilt test done; group III (n = 20), generalized anxiety disorder, no syncope; group IV (n = 80), arterial hypertension, no syncope. Hyperventilation was found in 11/14 patients in group I, 5/50 in group II, 7/20 in group III, and none in group IV; HV syncope was diagnosed in seven patients, all in group I. None of the parameters measured in the evaluation, including ETPCO2, predicted HV syncope on tilting. The mechanisms of resting HV and HV during tilt are not well understood. We confirm the existence of HV syncope. The tilt test should probably be used to screen patients presenting with syncope, with the CTT reserved for patients who lose consciousness during the tilt test without an associated fall in blood pressure, as HV is not always clinically obvious.
Download full-text PDF |
Source |
---|---|
http://dx.doi.org/10.1093/qjmed/90.2.139 | DOI Listing |
Mult Scler Relat Disord
January 2025
University of Health Sciences, Bakırköy Prof. Dr. Mazhar Osman Training and Research Hospital for Mental Health and Neurological Disorders, Department of Neurology, Istanbul, Türkiye. Electronic address:
Background: Multiple sclerosis (MS) patients frequently experience gait disturbances, which can be exacerbated in those with vestibular involvement. Various exercise approaches are available to address gait difficulties in this patient population, and the use of vestibular rehabilitation, in particular, has increased recently. However, the effects of this specific exercise approach on gait in MS patients remain unclear.
View Article and Find Full Text PDFPosition detection of elements, especially with high-precision and high-efficiency, continue to present challenges in the off-axis three-mirror space optical system to ensure the imaging quality. To test the position of elements in an off-axis three-mirror system, a method based on ResNet50 and Long short-term memory (LSTM) is proposed in this paper. In the proposed method, point spread function (PSF) with different fields of view is extracted as a high dimensional feature vector by the ResNet50 network to achieve high efficiency.
View Article and Find Full Text PDFPLoS One
January 2025
Department of Neurology, Korea University Guro Hospital, Korea University College of Medicine, Seoul, Republic of Korea.
Background: Visual dysfunction, including abnormal stereopsis, is a significant non-motor symptom in Parkinson's disease (PD) that can reduce quality of life and appears early in the disease. Abnormal stereopsis is associated with worsening of bradykinesia and freezing of gait, though the exact pathways linking stereopsis to motor symptoms remain unclear. Furthermore, in PD patients, the pedunculopontine nucleus and laterodorsal tegmental complex play an active role in sensorimotor control, and these areas provide cholinergic projections.
View Article and Find Full Text PDFFront Cardiovasc Med
January 2025
Department of Cardiology, Beijing Tsinghua Changgung Hospital, School of Clinical Medicine, Tsinghua University, Beijing, China.
Background: Painful left bundle branch block (LBBB) syndrome is an uncommon disease that is defined as intermittent episodes of angina associated with simultaneous LBBB changes on an electrocardiogram (ECG) with the absence of flow-limiting coronary artery disease or ischemia on functional testing. Vasovagal syncope (VVS) is the most common cause of syncope and can be provoked by sublingual nitroglycerin (NTG). Herein, we report a case of painful LBBB syndrome complicated with VVS, which was misdiagnosed as acute coronary syndrome and cardiogenic shock.
View Article and Find Full Text PDFOrthop Surg
January 2025
Department of Orthopedic Surgery, The General Hospital of the People's Liberation Army, Beijing, China.
Objective: Determining the optimal osteotomy length for patients with unilateral Crowe-IV developmental dysplasia of the hip undergoing subtrochanteric osteotomy remains challenging due to the significant variability in pelvic and spinal alignment. Incorrect osteotomy length, compounded by pelvic or spinal tilt, can adversely affect postoperative gait and long-term outcomes. Therefore, this study could introduce a method to calculate the osteotomy length for patients with unilateral Crowe-IV developmental dysplasia of the hip, correcting spinal and pelvic tilt, and improving patient gait.
View Article and Find Full Text PDFEnter search terms and have AI summaries delivered each week - change queries or unsubscribe any time!