Objective:To observe the incidence of syncope in patients with acute and critical cardiovascular diseases and to explore the risk factors of death.Methods:925 cases of acute heart failure, acute myocardial infarction, pulmonary embolism, arrhythmia and aortic dissection rupture who participated in Prospective, Multi-CenterRegistered Research Project for Chinese Syncope Patients from March 2018 to March 2020, admitted to the department of emergency of Nanyang Second General Hospital were selected as the research objects. The incidence and mortality of syncope were recorded, and the patients were divided into syncope group and non-syncope group according to whether they were accompanied by syncope or not. The incidence of syncope in male and female patients with different cardiovascular critical diseases, the age and mortality of cardiovascular critical patients with syncope or not were analyzed and compared. Multivariate Logistic regression analysis was used to analyze the risk factors of death, and receiver operating characteristic curve (ROC curve) was drawn to evaluate the predictive value of risk factors on the prognosis of patients.Results:The incidence of syncope in 5 kinds of cardiovascular critical patients from high to low was: acute myocardial infarction 3.03% (28/925), arrhythmia 2.70% (25/925), pulmonary embolism 1.51% (14/925), aortic dissection rupture 1.41% (13/925), acute heart failure 0.65% (6/925), with statistically significant differences ( χ2 = 10.765, P = 0.010). There was no significant difference in the incidence of syncope between male and female patients with pulmonary embolism, aortic dissection rupture, acute myocardial infarction, arrhythmia and acute heart failure. The age of patients with aortic dissection rupture, acute myocardial infarction and arrhythmia in syncope group were significantly higher than those in non-syncope group [aortic dissection rupture (years old): 66.29±15.64 vs. 57.63±14.23, acute myocardial infarction (years old): 69.55±15.13 vs. 62.10±15.75, arrhythmia (years old): 70.48±14.93 vs. 60.29±16.31, all P < 0.05]. The mortality of patients with pulmonary embolism, aortic dissection rupture, acute myocardial infarction, arrhythmia, acute heart failure in syncope group were significantly higher than those in non-syncope group [pulmonary embolism: 5.81% (5/86) vs. 0.95% (8/839), aortic dissection rupture: 4.65% (4/86) vs. 0.60% (5/839), acute myocardial infarction: 4.65% (4/86) vs. 1.19% (10/839), arrhythmia: 2.33% (2/86) vs. 0.95% (8/839), acute heart failure: 2.33% (2/86) vs. 0.60% (5/839), all P < 0.05]. Multivariate Logistic regression analysis showed that age [odds ratio ( OR) = 2.158, 95% confidence interval (95% CI) was 0.921-4.785, P = 0.000], pulmonary embolism ( OR = 15.391, 95% CI was 8.904-27.314, P = 0.001), aortic dissection rupture ( OR = 13.079, 95% CI was 6.237-25.509, P = 0.000), acute myocardial infarction ( OR = 18.826, 95% CI was 10.420-32.921, P = 0.000), syncope ( OR = 4.940, 95% CI was 1.764-9.287, P = 0.000) were risk factors for the prognosis of patients with acute and critical cardiovascular diseases. ROC curve analysis showed that syncope had a certain predictive value for 28-day prognosis of patients [the area under the ROC curve (AUC) = 0.760, P = 0.000], when the cut-off value was 4.12, the sensitivity was 88.51%, the specificity was 78.05%, the positive predictive value was 81.31%, and the negative predictive value was 84.27%. Conclusions:Syncope is an independent risk factor of death in patients with acute and critical cardiovascular diseases. For patients with syncope as the chief complaint, we should quickly identify the types of acute and critical diseases and assess the risk of sudden death.

Objective:To evaluate the effectiveness of syncope unit in improving the diagnosis efficiency and treatment prognosis of patients with suspected syncope.Methods:The standardized syncope unit was established in the Affiliated Nanyang Second General Hospital of Xinxiang Medical College in 2018. Patients with suspected syncope attending from November 2018 to April 2019 (before the establishment of syncope unit) and from May to October 2019 (after the establishment of syncope unit) were enrolled in the study. There were 109 cases attending before the establishment of syncope unit (control group) and 126 cases attending after establishment (syncope unit group). The positive rate of examination, the treatment and its cost before and after the establishment of syncope unit were compared. After one year, the follow-up rate, recurrence rate, rehospitalization rate, treatment satisfaction and quality of life of patients were documented and compared between two periods.Results:The positive rates of tilt table test [61.90%), Holter monitoring [64.29%(81/126)], exercise stress test [7.14%(9/126)] invasive electrophysiology [40.48%(51/126)], cardiac imaging [9.52%(12/126)] and 24-h blood pressure monitoring [55.56%(70/126)] in syncope unit group were significantly higher than those in control group [44.95%(49/109), 36.70%(40/109), 5.50%(6/109), 10.09%(11/109), 2.75%(3/109) and 40.37%(44/109); χ2=19.28, 23.11, 6.93, 28.18, 15.85 and 11.61,respectively; all P<0.01]. The diagnostic rate of etiology in syncope unit group was significantly higher than that in control group [87.30%(110/126) vs. 77.06%(84/109), χ2=21.70, P<0.01].The time from onset to cardiac assessment and hospitalization time in syncope unit group were significantly shorter than those in control group[(3.68±1.93)h vs. (7.31±2.64)h;(6.17±1.52)d vs. (10.83±2.09)d]. The hospitalization rate [3.17%(4/126) vs. 8.26%(8/109)], hospital mortality [0.79%(1/126) vs. 2.75%(3/109)] and treatment cost [(4.91±1.14) thousands Yuan vs. (7.05±2.53) thousands Yuan] in syncope unit group were significantly lower than those in control group ( t=14.49, P<0.01; t=8.62, P=0.02;χ2=15.83, P<0.01;χ2=10.03, P=0.01; t=6.17, P=0.03).The outpatient follow-up rate [82.54%(104/126)] and treatment satisfaction rate [91.35%(95/104)] in syncope unit group were significantly higher than those in control group [61.47%(67/109) and 64.18%(43/67)]; and the recurrence rate [14.42%(15/104)] and rehospitalization rate [7.69%(8/104)] in syncope unit group were significantly lower than those in control group [40.30%(27/67) and 23.88%(16/67)](χ2=17.30, 20.37, 18.56, 15.08,all P<0.01). The scores of psychological status, physiological status, environmental status, social relations and overall quality of life in contral group were significantly lower than those in syncope unit group (43.62±12.84 vs. 59.13±13.95,43.10±11.31 vs. 5.86±12.09,52.35±12.76 vs. 63.58±13.05,54.87±12.08 vs. 67.91±14.23,58.42±11.87 vs. 69.28±13.51; t=7.74, P=0.03; t=7.50, P=0.03; t=8.66, P=0.02; t=9.77, P=0.01; t=8.46, P=0.02, respectively). Conclusion:The establishment of standardized syncope unit is helpful to improve the diagnosis efficiency and the prognosis of patients with suspected syncope, and also reduce the cost of diagnosis and treatment.