Objective   To explore the principles and clinical applications of CR lead ECGs. Methods   The CR lead system is a bipolar chest lead system with a common negative electrode. The right upper limb (R) is its common negative electrode,  the positive electrode is a point on the chest (C), and  each point of  V leads were multiply chosen. We can obtain CR lead ECGs by the following  two methods. The first method is to make direct acquisition by a conventional ECG machine, with all four limb electrodes connected to the right upper limb and the chest lead electrode connected normally. The second method is to obtain CR lead ECGs through lead conversion based on conventional ECG data. First, the original data of leads such as aVR, V1-V6, V3R-V5R and V7-V9 were retrieved, and then a fixed conversion coefficient CR-Vi=Vi－2/3aVR was used to calculate the target lead (the algorithm was implemented under the compiling environment of Pycharm in Python language); finally, the conversion is completed and plotted. ResultsBoth the direct acquisition method and the conversion method obtained the same CR lead ECGs. However, compared with the corresponding Wilson lead ECG,  CR lead ECG in the left chest lead had a similar morphology but slightly great wave amplitudes while  CR lead ECG in the right chest lead had similar wave amplitudes but distinctly different wave morphology. The CR lead ECG in the right chest lead had a clear P wave, an upward QRS complex with no wide or deep Q wave, and an upright T wave. Wilson lead ECG had a lower P wave, a downward QRS complex, and could exhibit noninfarctionrelated wide and deep Q waves and nonischemic T wave inversion, known as the socalled right ventricular blind zone. Conclusion  CR lead ECG opens up the right ventricular blind zone, and achieves equal detection of the left and right ventricles, providing more valuable ECG morphological information for clinical practice and compensating for the limitations of the Wilson chest lead system. It is worthy of being promoted and popularized.

Handheld ECG collector is a simple bipolar singlelead ECG recording device. A standard Ⅰlead ECG can be conveniently recorded just by pressing the positive and negative electrodes with both thumbs. It is mainly utilized in the monitoring of arrhythmias. As a household medical equipment, it is quite popular with the majority of middleaged and elderly friends. Based on the nature of unipolar  and bipolar leads, and their intrinsic connection, this paper derives a recording method of standard leads and augmented unipolar leads. Meanwhile, on the basis of further exploring the internal connection between CR lead and Wilson lead, the method of directly recording CR chest lead ECGs by handheld ECG collector is creatively proposed. Both theory and practice show that the equivalent recording method of augmented unipolar limb lead and the bipolar recording method of CR chest lead can not only meet the clinical needs, but also prove to be unique. This method can fully develop the medical value of household medical devices, which is worthy of be promoted and popularized.

病理性Q波在心电学诊断中较为常见，可见于心肌梗死患者，也可由其他病因所致。本文就临床诊治的心电图均表现为病理性Q波的3例病例，从心电向量图特征、临床病史及相关检查等方面，对其病理性Q波的形成进行解析，以期为病理性Q波的诊断与鉴别诊断提供新的分析思路。

In the past, it has been generally accepted that tachyarrhythmias other than atrial fibrillation (AF) such as atrial premature beats (APB) and atrial tachycardia (AT) are not of great clinical significance. However, with the development of detection methods in recent years, more and more clinical studies have found that the atrial ectopic activities of APB and AT except for AF are associated with the risk of stroke, and may further contribute to increased mortality. Meanwhile, a positive association has also been revealed between the frequency of this kind of atrial yarrhythmias, and incidence of adverse events such as AF and ischemic stroke, which may be mediated by subclinical atrial cardiomyopathy. There is still no clear definition of the clinical threshold for this type of arrhythmia and its excessive supraventricular ectopic activities at present. Therefore, it is essential to make regular detection and management of tachyarrhythmia other than AF by means such as ambulatory electrocardiography and by following standardized process. This article describes the relationship between such atrial arrhythmias and cardiogenic stroke, and introduces the role of detecting such arrhythmias in the assessment of cardiogenic stroke.

Deceleration capacity of rate (DC) is one of the indicators reflecting the function of autonomic nervous regulation. Due to its noninvasiveness, and high sensitivity and specificity, it had been widely used in the prognosis and sudden death risk assessment of cardiovascular diseases at present. In recent years, domestic and foreign researchers have applied DC detection to research related to diseases other than heart diseases, and have made great progress. This article reviews the clinical research progress related to DC at home and abroad, aiming to further comprehensively and systematically sort out the clinical application value and potential  of DC.

Epicardial adipose tissue (EAT) as an active endocrine tissue located on the surface of the heart, not only provides energy for the heart, but also participates in inflammatory responses and metabolic regulation. Increased amount of epicardial adipose is significantly associated with the increased incidence of atrial fibrillation (AF), potentially promoting the occurrence and persistence of AF through mechanisms such as enhancing local cardiac inflammation, increasing oxidative stress, or directly affecting the electrophysiological properties of cardiomyocytes. This paper reviews the current research status on the relationship between EAT and AF, explores their association mechanism, and proposes future research directions regarding the role of EAT in AF pathogenesis.

Objective  To investigate the clinical significance of 24hour ambulatory electrocardiography (AECG) in patients with pacemaker implantation. Methods  A total of 65 patients with pacemaker implantation were selected as research subjects, and all of them both underwent routine 12 lead electrocardiogram(ECG) and 24hour AECG. The detection rates of pacemaker dysfunction \[abnormal pacing, and abnormal perception (absence of atrial perception, atrial over perception, absence of ventricular perception and ventricular over perception)\], special functions of pacemaker (pacing mode switching, frequency response, frequency lag, dynamic threshold monitoring and ventricular pacing management), self arrhythmias (atrial tachycardia, paroxysmal atrial fibrillation, atrial premature beats and premature ventricular beats), and pacemaker mediated arrhythmias (atrioventricular block, pacemaker mediated tachycardia, rapid rate and ventricular escape) separately by the two examination methods were compared. Results  By using 24hour AECG, the detection rates of pacemaker dysfunction and abnormal perception, and special functions of pacemaker such as pacing mode switching and frequency response were all significantly higher than those of routine ECG (P<0.05). The detection rates of self arrhythmias and pacemaker mediated arrhythmias were also significantly higher than those of routine ECG (P<0.05). Conclusion  The 24-hour AECG examination could effectively detect the working state of pacemaker in patients implanted with pacemaker, and sensitively make judgment of pacemaker dysfunction and cardiovascular events such as arrhythmias.

Objective  To explore the characteristics of abnormal ECGs in elderly population aged 90 and above as well as their clinical significance. Methods  A retrospective analysis was conducted on the clinical data of 204 hospitalized patients aged 90 and above. These patients were divided into two groups based on sex (114 males and 90 females). Baseline clinical data, fasting blood glucose, blood lipids, liver and kidney function, brain natriuretic peptide(BNP), ECG, and echocardiography examination results were compared and analyzed between the two groups. Results  Systolic blood pressure and triglyceride levels at admission were significantly higher in the female group compared to the male group (P<0.05), while creatinine and blood urea nitrogen levels were significantly higher in the male group (P<0.05). Sinus rhythm was observed in 765% of the patients. According to the detection rate from high to low, the most common ECG abnormalities were ST-T changes (46.1%), atrial premature beats (22.1%), firstdegree atrioventricular block (22.1%), right bundle branch block (19.6%), and atrial fibrillation (13.7%) in order. The detection rates of atrial flutter, atrial premature beats, premature ventricular contraction, right bundle branch block, firstdegree atrioventricular block, and left anterior fascicular block were all higher in the male group than those in the female group. Conclusion  ECG abnormalities are common in hospitalized patients aged 90 and above, primarily manifesting as ST-T changes, atrial premature beats, firstdegree atrioventricular block, right bundle branch block, and atrial fibrillation. The distribution of these ECG abnormalities differs between different sexes.

Objective To analyze initial and reexaminations of ECGs among enlisted male youths excluding functional changes due to various adverse influencing factors so as to prevent adverse cardiac events after enlistment and ensure the selection of physically and psychologically qualified candidates for the military. Methods Retrospective analysis was performed in the ECG examination results of 2 065 enlisted male youths. The age range of the examines was 18 to 22 years with a mean of (20.0±1.5) years. According to ECG diagnostic criteria, ECG changes of initial and reexaminations were analyzed. ResultsAmong the 2 065 enlisted male youths, abnormal ECGs were detected in 330 cases: sinus tachycardia in 30 cases (including 13 cases with concurrent ST-T changes), sinus bradycardia in 11 cases, premature beats in 19 cases, STT changes in 60 cases, early repolarization with elevated J point in 80 cases, right ventricular dominance in 12 cases, short PR interval in 56 cases, significant axis deviation in 10 cases, firstdegree atrioventricular block in 25 cases, seconddegree atrioventricular block in 1 case, left anterior fascicular block in 6 cases, atrial rhythm and atrial escape rhythm in 2 cases each, complete right bundle branch block in 12 cases, atrial fibrillation in 1 case, and ventricular preexcitation in 3 cases. A week later, reexamination was performed in the 330 cases with abnormal ECGs out of whom 277 cases turned to be normal, including sinus tachycardia (including 11 cases with concurrent ST-T changes) in 28 cases (93.33%), sinus bradycardia in 11 cases (100%), premature beats in 17 cases (89.47%), ST-T changes in 56 cases (93.33%), early repolarization with elevated J point in 68 cases (85.00%), right ventricular dominance in 11 cases (91.67%), short PR interval in 50 cases (89.29%), significant axis deviation in 8 cases (80.00%), firstdegree atrioventricular block in 22 cases(88.00%), left anterior fascicular block in 2 cases (33.33%), and atrial rhythm and atrial escape rhythm in 2 cases each (100%); the remaining cases were all unqualified in the reexamination. Except for seconddegree atrioventricular block, left anterior fascicular block, complete right bundle branch block, atrial fibrillation and ventricular preexcitation, there were statistically significant differences in the incidences of other ECG abnormalities between initial and reexaminations (all P<0.05). ConclusionBefore physical examinations of enlisted male youths, they should correct unhealthy living habits and keep a positive attitude in advance. ECG physicians should patiently recheck unqualified ECGs to exclude functional changes before confirming unqualified ECG results.

Objective  To investigate the changes of serum creatine kinase isoenzyme (CK-MB), homocysteine (Hcy) and B-type natriuretic peptide (BNP) levels in patients with acute myocardial infarction (AMI), and to analyze their correlation with the severity of the disease and their predictive value on major adverse cardiovascular events (MACEs). Methods   A total of 102 patients with AMI were selected as the research group while another 102 healthy physical examinees during the same period were selected as the control group. The changes of serum CK-MB, Hcy and BNP levels were compared separately between different groups and among the enrolled patients with different numbers of coronary lesions. Spearman and Pearson correlation analysis was utilized to explore the correlation between serum indicators and the number of coronary lesions or Gensini score. Patients in the research group were treated by percutaneous coronary intervention (PCI). They were divided into subgroups with or without MACEs according to the presence or absence of MACEs 6 months after the surgery. The serum CK-MB, Hcy and BNP levels were analyzed in each group before PCI and one month after the surgery. The predictive value of each serum indicator level one month after operation on MACEs was analyzed by using ROC curve. ResultsThe serum levels of CK-MB, Hcy and BNP in the research group were higher than those in the control group (P<0.01); serum CK-MB, Hcy and BNP levels were positively correlated with the number of coronary lesions and Gensini score (P<0.05). One month after surgery, the serum CK-MB, Hcy and BNP levels of the patients with MACEs were higher than those of the patients without MACEs (P<0.05). The AUC value of the combination of serum CK-MB, Hcy and BNP levels one month after surgery for MACEs was 0.943, which was higher than the AUC value of single indicator (0.769, 0.847 and 0.794, respectively;P<0.05). Conclusion  The serum levels of CK-MB, Hcy and BNP in AMI patients are elevated, which are closely related to the severity of the disease. The combined detection of the above serum indicators has certain predictive value for the occurrence of MACEs.

电张调整性T波的累积作用引起的T波改变属于功能性改变，对其充分认识并正确判断，可以避免一些不必要的特殊检查及治疗。特发性室性心动过速频繁发作时，可显示出电张调整性T波改变。  本文对典型的电张调整性T波改变患者前后相隔一周的两次动态心电图进行比较和分析，探讨电张调整性T波改变后的累积作用及其与特发性室性心动过速持续时间与次数的关系。

ObjectiveTo investigate the diagnostic efficiency of routine electrocardiogram (ECG) and ambulatory electrocardiography (AECG) for coronary heart disease (CHD), and to analyze the characteristics of fragmented QRS complex (fQRS) in ECG, providing references for making early clinical diagnosis and intervention program. MethodsWe selected 80 patients with suspected CHD as research objects. ECG and AECG examinations were both performed on them after admission. With the results of coronary angiography as “gold standard”, statistics were performed on the diagnostic results and efficiency of ECG and AECG for CHD, and the detection rates of different types of arrhythmias in CHD patients were compared between the two examination methods. The characteristics of fQRS in ECG were analyzed among CHD patients. ResultsThe results of ECG examination showed that in the 80 examinees, there were 45 arrhythmia positive cases and 35 negative cases, while AECG examination detected 55 positive cases and 25 negative cases. Compared with ECG, the sensitivity and accuracy rate of AECG for the diagnosis of CHD were significantly higher (74.14% vs. 93.10%, 78.75% vs. 93.75%), while the rate of missed diagnosis was significantly lower (25.76% vs. 6.90%, all P＜0.05). The detection rates of atrioventricular block, atrial premature beats, premature ventricular contraction, paired atrial premature beats, paired premature ventricular contraction, short paroxysmal supraventricular tachycardia and paroxysmal atrial fibrillation by AECG examination in CHD patients were significantly higher than those by ECG (all P＜0.05). The incidence of ECG fQRS in CHD patients was significantly higher than that in cases without CHD (P＜0.05), and most of fQRS occurred in the inferior wall lead. ConclusionThe accuracy rate of AECG in the diagnosis of CHD is significantly higher than that of ECG, which provides a basis for clinical early screening and diagnosis. AECG could be used to evaluate arrhythmias clinically and formulate intervention programs correspondingly.

Atrial fibrillation (AF) is one of the most common arrhythmias. It is characterized by concealment, paroxysmal nature, complexity, and high mortality and disability rate; the prevalence rate of AF is on the rise. The new emergence of artificial intelligence technology breaks through the limitations of traditional methods of AF screening, showing unique advantages and broad application prospects in the screening, diagnosis and prediction of AF. Intelligent wearable devices have higher feasibility, specificity and sensitivity in the screening  of AF, with high cost-effectiveness in clinical application.

Cancer is the second leading cause of mortality worldwide, and a quarter of global cancerrelated deaths occur in China. At present, cardiovascular disease has emerged as the second most common cause of death among cancer survivors subsequent to cancer recurrence and metastasis. Accurate prediction and early diagnosis of potential cardiovascular toxicity during cancer treatment could not only optimize patients clinical outcomes but also could alleviate the burden on the healthcare system. This article provides a comprehensive overview of recent research pertaining to predicting and early diagnosing cancer therapyrelated cardiovascular toxicity, offering valuable insights into identifying highrisk patients.

患者男，28岁，因“突发心慌4 h”入院。入院时诊断为室上性心律失常。静脉推注普罗帕酮复律后，患者心电图提示室性心动过速(简称室速)，随即意识丧失，予以非同步电复律，抢救成功，后入院行心内电生理检查，证实为房室结折返性心动过速，行导管消融术，消融治疗成功。经反复心内电生理检查，未诱发室速，证实室速为普罗帕酮所致。本文对普罗帕酮导致的室速病例进行分析，旨在为该药的临床安全应用提供参考，同时提醒医疗人员注意：使用抗心律失常药物可能有促心律失常作用，使用时应进行严密心电监测。

ObjectiveTo understand the performances of cardiac electrical activities in college students, and to analyze the detection and characteristics of ECG abnormalities among them, providing references for identifying those requiring further examinations and screening high risky population based on ECGs. MethodsWe collected the ECGs of 1 003 college students who had been enrolled in 2022 and had undergone physical examination. Descriptive statistical analysis was performed on the population distribution characteristics of ECGs and ECG parameters by different sexes and different ethnic groups. ResultsThere were 459 cases (45.8%) of normal ECGs while abnormal ones were detected in 544 cases (54.2%). The detection of abnormal ECGs was as follows: sinus arrhythmia accounted for 36.7%, sinus tachycardia accounted for 2.2%, sinus bradycardia with arrhythmia accounted for 5.5%, premature contraction accounted for 1.8%, bundle branch block accounted for 1.7%, and ST-T changes accounted for 2.5%. The detection rate of abnormal ECGs was higher in females than that in males, and the difference was statistically significant (P<0.01). Among the male and female college students, the differences of ECG related parameters including Pwave duration, QRS complex duration, QT interval, and RV5 and SV1 amplitudes were all statistically significant (all P<0.05). ConclusionThe detection rate of abnormal ECGs in college students physical examination was relatively high. Their ECG changes may be associated with autonomic nerve dysfunction and the boundary value settings of ECG parameters. Therefore, in diagnosing ECGs of physical examination, careful judgment of whether ECG changes are physiological or pathological is required in case of misdiagnosis, resulting in stress to examinees family members and wasting of medical resources. ECG related parameters differ less between sexes in college students, and thus the difference could be ignored in actual clinical operation.

Objective  To investigate the importance of standard operation of ECG examination for quality control of remote ECG network. Methods  We analyzed ECGs transmitted through the network from January 1,2022 to June 30,2023 at the ECG Network Center of the First People’s Hospital of Xianyang. During the time period, we took every six months as a stage, and performed targeted operation training of ECG examination at each stage. We compared the graphic quality problems and the number of ECGs with quality problems among different stages. Results  After regular ECG operation training for clinical medical staff and instrument maintenance, the quality of ECG graphics has been greatly improved. Conclusion  Standard operation of remote ECG network directly affects the diagnostic accuracy of ECGs. Regular standardized training of ECG operation for clinical medical staff could improve the accuracy of ECG examination results, and avoid the occurrence of medical adverse events.

The prevalence rate of cardiovascular diseases in China has been increasing, therefore the precise diagnosis and treatment of arrhythmias is particularly critical. ECG examination is the main basis for the diagnosis of arrhythmias. At present, artificial intelligence ECG analysis technology has brought new possibilities to improve the efficiency and accuracy of clinical diagnosis and treatment of arrhythmias. This paper reviews the latest progress in the application of artificial intelligence ECG analysis technology at home and abroad, and summarizes the prospects and challenges of the technology in the diagnosis of arrhythmias.

Objective  To analyze the value of arteriosclerosis index combined with pulse pressure index in predicting the degree of coronary artery lesions in patients with coronary heart disease (CHD). Methods  Seventy-two patients with CHD were selected, and divided into singlebranch group (21 cases), double-branches group (34 cases) and threebranches group (17 cases) according to the number of lesioned coronary arteries. Arteriosclerosis index and pulse pressure index were compared among the three groups. Pearson correlation analysis was used to explore the relationship between the indexes and the degree of coronary artery lesions. ROC curve was drawn to analyze the predictive value of the combined index. Results  The arteriosclerosis index and Gensini score of the threebranches group were higher than those of the other two groups, and the pulse pressure index was higher than that of the singlebranch group. Arteriosclerosis index and Gensini score in the doublebranches group were higher than those in the singlebranch group (P<0.05). The arteriosclerosis index and pulse pressure index were both positively correlated with Gensini score. ROC curve was drawn taking the double and threebranches groups as a whole and the singlebranch group as the control. The results showed that arteriosclerosis index and pulse pressure index had certain predictive value for the degree of coronary artery disease in patients with CHD (AUC=0.897 and 0.697,respectively), and the combined detection had greater predictive value (AUC=0.924). Conclusion  Arteriosclerosis index and pulse pressure index are closely related to the degree of coronary artery disease in patients with CHD. The combined detection of the two indexes has greater predictive value for the degree of coronary artery disease.

Objective  To explore the diagnostic value of Peguero-Lo Presti index on heart failure with preserved ejection fraction (HFpEF). Methods  We selected patients with clinical symptoms of heart failure (HF) who had been hospitalized in the Department of Cardiology of Provincial Clinical Medical College, Fujian Medical University; their clinical data were complete, including ECGs, cardiac ultrasound, biochemistry, and NT-proBNP. Based on the HFA-PEFF score standard recommended by the Guidelines for the diagnosis and treatment of acute and chronic HF, 120 patients were enrolled in the HFpEF group (60 males and 60 females) while 100 cases without HF were divided into the control group (56 males and 44 females). The baseline data characteristics were compared between the two groups. Peguero-Lo Presti index, Cornell product index, and RomhiltEstes score were separately calculated and analyzed in the standard 12lead ECGs. We compared the area under the ROC curve, sensitivity and specificity of the above three indicators for diagnosing HFpEF. Results  Compared with the control group, there was no statistically significant difference in the baseline data such as sex, age, diabetes proportion, coronary heart disease, highdensity lipoprotein cholesterol, and serum creatinine in the HFpEF group (P>0.05); the proportion of hypertension, lowdensity lipoprotein cholesterol and hyperuricemia increased (P<0.05). In the male subgroup, the area under the ROC curve of the Peguero-Lo Presti index was 0.84 (0.76, 0.90), which was higher than that of the Cornell product index \[0.70 (0.61, 0.78)\] and that of the Romhilt-Estes score[0.62 (0.53, 0.71)\ (all P<0.05). The sensitivity of the PegueroLo Presti index was 6667%, which was higher than that of the Romhilt-Estes score (36.57%) and that of the Cornell product index (48.33%), with statistically significant differences (all P<0.05) while the difference of specificity was not statistically significant. In the female subgroup, the area under the ROC curve of the Peguero-Lo Presti index was 0.77 (0.69, 0.85), which was higher than that of the Cornell product index [0.68 (0.58, 0.77)] and that of the Romhilt-Estes score [0.57(0.47, 0.66)， all P<0.05］. The sensitivity of the Peguero-Lo Presti index was 68.33%, which was higher than that of the Romhilt-Estes score (26.67%), with statistically significant difference (P<0.01) while the difference of specificity was not statistically significant. Conclusion  The Peguero-Lo Presti index of ECG has high sensitivity and specificity for diagnosing HFpEF. The examination method is convenient, and could be used as an auxiliary diagnosis and screening index for HFpEF clinically.

Objective  To analyze the ECG characteristics of patients with human immunodeficiency virus (HIV) infection and acquired immunodeficiency syndrome (AIDS) among Zhuang ethnic group in Guangxi Zhuang Autonomous Region so as to provide clinical basis for the diagnosis and treatment of this kind of population. Methods  We selected 200 cases infected with HIV and 200 AIDS patients from inhabitants of Guangxi Zhuang Autonomous Region who had been hospitalized in our hospital, separately as infection group and patient group. In addition, 200 healthy physical examinees during the same time period were selected as control group. Routine 12-lead ECG detection was performed on the three groups of research subjects. We compared active arrhythmia, passive arrhythmia, ST-T changes, QT interval/QTc prolongation and other abnormal ECG changes. Results  In the infection group and the patient group, the incidences of active arrhythmias, passive arrhythmias, QT interval/QTc prolongation were all significantly higher than those in the control group. The incidences of the above three abnormal ECG changes in the patient group were also significantly higher than those in the infection group (all P<0.05). Conclusion  Abnormal ECG changes are more common among patients with HIV infection and AIDS in Guangxi Zhuang population, mainly arrhythmias, ST-T changes and QT interval/QTc prolongation. Clinicians need to pay close attention to abnormal ECG changes of patients with HIV infection and AIDS patients among these population in order to prevent adverse cardiac events.

Objective  To compare the effectiveness and safety of secondgeneration cryoballoon ablation and conventional drug therapy separately as the initial treatment for patients with paroxysmal atrial fibrillation (AF). Methods  We selected 44 patients with paroxysmal AF who had been initially treated by secondgeneration cryoballoon ablation as the ablation group. The operation time, ablation time, X-ray fluoroscopy time, pulmonary vein isolation rate, and surgical complications were observed. We selected another 44 inpatients with paroxysmal AF who had been initially treated by drug therapy during the same period as the medication group. The two groups were followed up separately one month, and 3, 6 and 12 months after discharge to observe the recurrence rate and complications of AF. The efficacy and safety of treatment were further compared between the two groups. Results  The operation time, ablation time and X-ray fluoroscopy time of the ablation group were (108.0±39.0) minutes, (35.0±11.7) minutes and (10.0±6.9) minutes, respectively; the immediate isolation rate of pulmonary vein was 100%; there were 3 cases (6.8%) of operationrelated complications, including one case of vagus reflex and 2 cases of transient phrenic nerve injury. In the medication group, drug-induced sinus bradycardia occurred in 2 cases, QTc was prolonged in one case, and thyroid function was decreased in one case. After a mean follow-up of (12.0±5.) months, the recurrence rate of AF was 11.4% in the ablation group while the rate was 20.5% in the medication group. The recurrence rate in the ablation group was significantly lower than that in the medication group (P=0.033). The incidence of complications or adverse reactions did not vary significantly from the ablation group to the medication group (6.8% vs 9.1%, P=0.108). Conclusion  Compared with drug therapy, the secondgeneration cryoballoon ablation has a higher success rate for paroxysmal AF without increased risk of complications. The secondgeneration cryoballoon ablation can be considered as one of the initial treatment strategies for paroxysmal AF.

ObjectiveTo explore the characteristics of atrial, ventricular and junctional escape rhythms in ECG waterfall diagram, and to lay a foundation for rapidly analyzing ambulatory electrocardiography of chronic arrhythmias such as sick sinus syndrome (SSS). MethodsA patient diagnosed with SSS complicated by the above three escape rhythms were selected. The characteristics of ECG waterfall diagram were further analyzed based on the routine view of the ECG scatter plots. Combined with the reversal technique of ECG waterfall diagram, we analyzed and summarized the characteristics of ECG waterfall diagrams of the three escape rhythms, and their correspondence with the corresponding ECGs. ResultsUnder the background of sinus block or sinus arrest, the frequencies of the three protective escape rhythms (atrial, ventricular and junctional escape rhythms) in the patient with SSS were close, competing with each other and alternating repeatedly. The characteristics revealed by the common analytical tools such as ECG scatter plot and RR interval histogram were not obvious, but the features of the ECG waterfall diagram of each rhythm were different which provided a shortcut to rapidly analyze this kind of cases. The R-peak band of normal sinus rhythm was horizontally centered and its width was 120 ms or less. The chromatogram represented the height of QRS complex. The P- and T-peak bands were in parallel, separately located at the upper and the bottom of R-peak band. The width and chromatography represented the duration and polarity of P- and T-waves, respectively. Rhythm transformation was indicated by the changes of the width or chromatography of the threepeakband ECG waterfall diagram of sinus rhythm. The ECG waterfall diagram characteristics of atrial escape rhythm were as follows: P-peak band was allochroic while R- and T-peak bands were normal. The ECG waterfall diagram characteristics of ventricular escape rhythm were as follows: P-peak band disappeared, R-peak band was widened and allochroic, and T-peak band changed its color. The ECG waterfall diagram characteristics of junctional escape rhythm were as follows: P-peak band disappeared while R- and T-peak bands were normal. ConclusionECG waterfall diagram could be used to quickly identify various kinds of escape rhythms in SSS patients, which makes up for the shortcomings of ECG scatter plot and RR interval histogram in ECG big data analysis.

Objective To explore the correlation between ST-segment depression, ST-T changes, and atrial premature beats (APB) or premature ventricular contraction (PVC). Methods  By univariate and multivariate Logistic regression analysis, retrospective analysis was conducted on clinical ECG data to determine the relationship between ST-segment depression, ST-T changes, and APB or PVC. Results  Analysis of the ECG data from 4 952 patients revealed a significant correlation of ST-segment depression and ST-T changes with APB and PVC. Among the patients with ST-segment depression, the incidences of APB and PVC separately increased to 9.00 and 13.65 times the incidences in the patients without ST-segment depression. Among the patients with ST-T changes, the incidences of APB and PVC separately increased to 27.60 and 22.00 times the incidences in the patients without ST-T changes. Multivariate Logistic regression analysis also found that ST-segment depression of up to 0.05 mV and ST-T changes were key factors influencing the occurrence of APB and PVC. Conclusion   ST-segment depression and ST-T changes may serve as risk factors for the occurrence of APB and PVC.

同时发生前壁和下壁急性ST段抬高型心肌梗死较为少见，其梗死相关血管主要为包绕心尖型左前降支闭塞。本例患者男，57岁，因被发现神志不清2 h入院。急诊心电图检查示：窦性心律，V3—V6、Ⅱ、Ⅲ、aVF导联ST段抬高0.1~0.5 mV。急诊冠状动脉造影证实其梗死相关血管为右冠状动脉近段完全闭塞。

Arrhythmia is one of the most common heart diseases and is usually a direct cause of sudden cardiac death. The stability of myocardial electrical activity depends on the balance of autonomic nervous system tension. Autonomic nervous system plays an important role in the onset and persistence of arrhythmias. This article reviews from aspects including the role of autonomic nerves in arrhythmias, intervention measures of autonomic nerve regulation, and assessment methods of autonomic nervous function, in order to provide an emerging therapeutic strategy for the prevention and treatment of arrhythmias.

More and more patients with renal artery stenosis (RAS) have been found in the clinical practice of cardiovascular disease. RAS is an important cause of hypertension and(or) renal insufficiency, and its main cause is atherosclerosis. In China, with aging of population, among the patients with coronary artery disease and peripheral vascular disease, those with atherosclerotic renal artery stenosis (ARAS) have been  constantly increasing. ARAS is one of the important causes of secondary hypertension. If ARAS patients can be found in an early phase, and made correction, diagnosis, treatment and effective intervention, it will be of positive significance for them to control blood pressure and improve the quality of life. This review focuses on the epidemiology for ARAS, the relationship between ARAS and hypertension, the diagnostic clues for ARAS, and its examination methods and treatment.

Atrial fibrillation (AF) is the most common arrhythmia and may easily lead to various complications. Therefore, precision medical methods are needed to identify and enhance AF detection to achieve early diagnosis and treatment. Artificial intelligencebased wearable devices are of great value for the screening and management of AF patients. This article reviews the relevant literature on recent applications of such devices for AF screening.