Evaluation of the usefulness of recording the ECG in the 3rd intercostal space and prevalence of Brugada-type ECG in accordance with recently established electrocardiographic criteria.

BACKGROUND: It has been reported that recording electrocardiograms (ECGs) in the 3rd intercostal space (ICS) is one method that can be used for detecting Brugada syndrome; however, the prevalence of Brugada-type ECGs recorded in the 3rd ICS and the usefulness of recording the ECG in the 3rd ICS in accordance with recently established electrocardiographic criteria is unknown. METHODS AND RESULTS: ECGs were recorded in both the 4th and 3rd ICS in 17 Brugada-type ECG patients (group A) and in 206 consecutive male subjects (group B). Brugada-type ECGs were divided into 3 types. In group A, the prevalence of type 1 ECG, which is a coved-type ECG with ST-segment elevation of >/=2 mm, increased from 23.5% to 64.7% when ECG was recorded in the 3rd ICS. The conversion to type 1 ECG was found to be related to induction of ventricular arrhythmia. In group B, the prevalence of Brugada-type ECG increased from 1.5% to 5.8% when the ECG was recorded in the 3rd ICS. CONCLUSIONS: Recording the ECG in the 3rd ICS is useful for identifying high-risk patients with Brugada-type ECG and for detecting concealed Brugada-type ECG.     

健康人高位右侧胸前导联Brugada心电图征调查

目的 初步了解我国健康人高位右侧胸前导联Brugada心电图征发生率及其意义。方法 对1005例健康体检者进行病史询问、体格检查、X线胸片、标准12导联和第二肋间右侧胸前导联心电图检查,按照欧洲心脏病学会制定的标准筛选Brugada心电图征。结果 排除4例器质性心脏病和心律失常患者后,共1001例（男877例,女124例）人选,年龄17～75（28．3±14．8）岁。标准导联心电图检查发现5例2型Brugada心电图征（0．5％）,第二肋间右侧胸前导联心电图检查发现47例Brugada心电图征（4．70％）,均为男性（2型40例,3型7例）。无不明原因晕厥或黑噱史,无猝死家族史。结论 对于症状不典型者,依据标准导联或高位右侧胸前导联2型或3型Brugada心电图征诊断Brugada综合征要慎重。     

Frequency of Brugada-type ECG pattern (Brugada sign) in Southern Turkey

The frequency of Brugada sign was found to differ among ethnic groups. Yet, there is no data regarding the prevalence of Brugada syndrome and sign in our country. The aim of this study was to determine the frequency of a Brugada-type electrocardiogram (ECG) pattern in southern Turkey. A total of 1,238 subjects (males, 671, females, 567) were included in the study. The previously archived ECGs of 807 subjects without any evidence of structural heart disease were chosen randomly and evaluated. In addition, prospective analysis of the ECGs of 431 subjects (males, 293, females, 138) randomly chosen from healthy university students were also included. The mean age was 38.9 +/- 17.6 years. Six subjects (0.48%) had a Brugada-type ECG pattern. One (0.08%) of them had the coved-type and 5 (0.40%) had the saddleback-type. All subjects were asymptomatic. A Brugada-type ECG pattern was obtained in 1 (0.17%) female and in 5 (0.74%) males (OR: 4.2 CI: 0.5-36.4, P = 0.2). The Brugada-type ECG pattern frequency was 0.12% in subjects >or= 25 years old and 1.16% in subjects between 17-24 years old (OR: 9.4 CI: 1.1-81.2, P = 0.02). Young males between 17-24 years had the highest (1.70%) frequency. The results indicate that the frequency of the Brugada-type ECG pattern was 0.48% in the general population, being more prevalent in young males in our region. These results are similar to the findings of studies performed in other countries.     

Prevalence and mortality of the Brugada-type electrocardiogram in one city in Japan

OBJECTIVES: We sought to study the prevalence and mortality of subjects exhibiting the Brugada-type electrocardiogram (ECG) in a community-based population in Japan. BACKGROUND: The Brugada syndrome has been associated with sudden death in subjects without structural heart disease. Hospital-based studies showed 11% to 38% annual fatal arrhythmic events in patients with the Brugada syndrome. METHODS: Prevalence and mortality of the Brugada-type ECG were studied in subjects who had ECGs during a health examination in Moriguchi, Osaka, Japan. Information about death and relocation from Moriguchi city was obtained prospectively. RESULTS: The Brugada-type ECG was found in 98 of 13,929 study subjects (0.70%, 95% confidence interval [CI]: 0.57% to 0.86%). The typical coved-type with an rsR' pattern in V(1) lead ("typical" Brugada-type) was found in 0.12% of subjects (95% CI: 0.07% to 0.20%). The prevalence for male subjects with the Brugada-type ECG (81%) was significantly higher than it was for those without (26%, p < 0.0001). In male subjects, the Brugada-type ECG was found in 2.14% (95% CI: 1.70% to 2.66%), and the "typical" Brugada-type was found in 0.38% (95% CI: 0.21% to 0.64%). After 2.6 +/- 0.3 years of follow-up, there was 1 death (1.0%, 95% CI: 0.03% to 5.6%) of a subject with the Brugada-type ECG, whereas there were 139 deaths (1.0%, 95% CI: 0.85% to 1.2%) of those without the Brugada-type ECG (p = 0.9943, log-rank test). CONCLUSIONS: A substantial number of the Brugada-type ECG were observed in subjects in a community-based population in Japan, especially in men. The total mortality of subjects with the Brugada-type ECG did not differ from the mortality of those without the Brugada-type ECG in a community-based population.     

The prevalence, incidence and prognostic value of the Brugada-type electrocardiogram: a population-based study of four decades

OBJECTIVES: We sought to demonstrate the prevalence, incidence and prognostic value of the Brugada-type electrocardiogram (ECG) in a general population. BACKGROUND: The Brugada syndrome is characterized by evidence of right bundle branch block and ST segment elevation in the right precordial leads, as well as sudden death caused by ventricular fibrillation. However, the natural history of the Brugada-type ECG remains unclear. METHODS: We investigated 4,788 subjects (1,956 men and 2,832 women) who were <50 years old in 1958 and had undergone biennial health examinations, including electrocardiography, through 1999. The Brugada-type ECG was defined as a terminal r' wave in lead V(1) and ST segment elevation > or =0.1 mV in leads V(1) and V(2). Unexpected death was defined as sudden death or unexplained accidental death. RESULTS: There were a total of 32 Brugada-type ECG cases; the prevalence and incidence were 146.2 in 100,000 persons and 14.2 persons per 100,000 person-years, respectively. The incidence was nine times higher among men than women, and the average age at presentation was 45 +/- 10.5 years. The Brugada-type ECG appeared intermittently in most cases and was found in 26% of subjects who died unexpectedly. Cox survival analysis revealed that mortality from unexpected death was significantly higher in subjects with a Brugada-type ECG than in control subjects (p < 0.01). Unexpected deaths were more frequent among subjects with the Brugada-type ECG who had a history of syncope (p < 0.05). CONCLUSIONS: The Brugada-type ECG is not a very rare condition in the adult Japanese population. Subjects with a Brugada-type ECG have an increased risk of unexpected death.     

Relationships between depolarization abnormality and repolarization abnormality in patients with Brugada syndrome: using body surface signal-averaged electrocardiography and body surface maps

INTRODUCTION: Repolarization and depolarization abnormalities have been reported to be related to Brugada syndrome. METHODS AND RESULTS: We evaluated the relationships between repolarization abnormality and depolarization abnormality using 48-lead unipolar signal-averaged electrocardiograms and 87-lead unipolar body surface maps in 15 patients with Brugada-type ECGs. Data were compared with those from healthy control subjects (n = 5) and within subgroups of Brugada syndrome with (n = 8) and without (n = 7) ventricular arrhythmias (VA) induced by programmed electrical stimulation (PES). Eighty-seven-lead body surface maps were recorded, and potential maps were constructed to evaluate elevation of the ST segment 20 ms after the J point. Forty-eight-lead signal-averaged ECGs were recorded, and isochronal maps of duration of the delayed potential (dDP) were constructed to evaluate the dDP in each lead. Potential maps showed that patients with Brugada-type ECG, especially those with VA induced by programmed electrical stimulation, had greater elevation of the ST segment in the right ventricular outflow tract, especially at E5. Isochronal maps of dDP in the Brugada-type ECG group showed that maximum dDP was located at E5 and that the area with long dDP was larger than that in the control subjects. The dDPs at E7, E5, F7, and F5 in the VA-inducible group were significantly longer than those in the VA-noninducible group. These results showed that the location of greater elevation in the ST segment coincided with the location of longer dDP. CONCLUSION: Repolarization abnormality and depolarization abnormality in the walls of both ventricles, especially in the right ventricular outflow tract, are related to the VA of Brugada syndrome.     

Brugada-type patterns are easily observed in high precordial lead ECGs in collegiate athletes

Background

Displacement of ECG leads can result in unwarranted findings. We assessed the frequency of Brugada-type patterns in athletes when precordial leads were purposely placed upward.

Methods

Four hundred ninety-one collegiate athletes underwent two ECGs: one with standard leads, one with V1 and V2 along the 2nd intercostal space. A positive Brugada-type pattern was defined as ST elevation in V1 or V2 consistent with a Type 1, 2, or 3 pattern in the high-lead ECG. A control group was comprised of 181 outpatients.

Results

No Type 1 patterns were seen. In 58 athletes (11.8%), a Brugada-type 2 or 3 pattern was observed. Those with Brugada-type 2 or 3 patterns were more likely male, taller, and heavier. In the control group, 18 (9.9%) had Brugada-type 2 or 3 patterns and were more likely male.

Conclusions

Proper lead positioning is essential to avoid unwarranted diagnosis of a Brugada-type ECG, especially in taller, heavier male athletes.     

Prevalence of Brugada sign in a Greek tertiary hospital population.

AIMS: The purpose of the present study was to determine for the first time the prevalence of Brugada-type electrocardiographic (ECG) pattern (Brugada sign) in unselected individuals served by an urban Greek tertiary hospital during a 4-year time period. METHODS AND RESULTS: Among 11,488 individuals (6640 males, 4848 females), 25 (23 males, 2 females, aged 36.8 +/- 19.2 years) were found to display the Brugada sign (0.22%). Two cases exhibited the diagnostic type 1 ECG pattern (0.02%) and 23 subjects fulfilled the ECG criteria for type 2 or 3 patterns (0.2%). The incidence of Brugada sign was higher among men (0.34%) than in women (0.04%). Structural heart disease was established in four cases (one of them exhibiting a type 1 ECG pattern). Twenty-one individuals (19 males, 2 females, aged 29.7 +/- 10.7 years) without structural heart disease displaying Brugada-type ECG features (4 cases with spontaneous or procainamide-induced type 1 ECG pattern) were subsequently selected and closely followed up for 24 +/- 12 months. No mortality or life-threatening ventricular arrhythmias were recorded during this period. CONCLUSION: The Brugada-type ECG pattern is infrequently seen in a Greek hospital-based population. All subjects with Brugada sign and structurally normal hearts displayed a benign clinical course without arrhythmic events during a relatively long follow-up period.     

Different effect of the pure Na+ channel-blocker pilsicainide on the ST-segment response in the right precordial leads in patients with normal left ventricular function.

BACKGROUND: The response of the ST-segment in the right precordial leads to Na+ channel blockers in patients without structural heart disease and a typical Brugada-type ECG has not been fully elucidated. METHODS AND RESULTS: A pilsicainide challenge test was performed in 161 patients and according to recently established ECG criteria and an organized computer algorithm, the ST morphology was classified and the maximum increase in the J wave amplitude (maxDeltaJ) from the standard and high right precordial leads V1-3 was examined. Before the test, subjects exhibiting type 1 ECG in the standard leads were excluded. After administering pilsicainide, type 1 ECGs in the standard leads were observed in 31 cases and a maxDeltaJ of >or=200 microV was observed in 29 cases (23 type 1, 2 type 2/3 and 4 normal ECGs). In the additional higher right precordial leads, type 1 ECGs were observed in 55 cases and a maxDeltaJ of >or=200 microV was observed in 45 cases (42 type 1 and 3 type 2/3 ECGs). CONCLUSIONS: A maxDeltaJ>or=200 microV induced by pilsicainide, including that measured in the high right precordial leads, was associated with a change mainly to a type 1 ECG.     

Withdrawal of inhaled corticosteroid therapy in long-term, stable, mild to moderate, persistent asthmatic patients.

We aimed to evaluate the effect of withdrawal of inhaled corticosteroid (ICS) therapy on the course of mild to moderate asthma. Nineteen cases with stable, mild to moderate asthma were included in this study. Patients had used ICSs regularly during the past year and had no symptoms and signs for the last 3 months prior to the study. The patients were randomized into two groups. Group 1 included 11 patients who were followed after withdrawal of ICS therapy (mean age 48.8 +/- 13.1 years; M/F: 2/9), while Group 2 included 8 patients still taking ICS therapy (mean age 47.2 +/- 14.8 years; M/F: 4/4). All subjects were seen at the end of the 1st (V2), 2nd (V3), 3rd (V4), 6th (V5), and 12th (V6) months. Symptom scores and FEV1 measurements were evaluated during these visits. Patients with relapses were excluded from the study. Bronchial challenge test was applied in all cases at V0, V4, V5, and V6. In 10 of 11 cases (90.9%) in which ICS therapy was discontinued, relapse was observed in 1.55 +/- 0.86 months, while in 2 of 8 subjects (25%) still taking ICSs, relapse occurred after 3.76 +/- 1.99 months. In Group 1, "mean symptom score" and "mean PC20FEV1" values measured during the whole follow-up period were found to be lower than in Group 2. We concluded that withdrawal of ICS therapy could increase the possibility of relapse in mild to moderate asthma even in asymptomatic and stable cases.     

Electrocardiographic Identification of Drug‐Induced QT Prolongation: Assessment by Different Recording and Measurement Methods

Background: Careful assessment of QT interval prolongation is required before novel drugs are approved by regulatory authorities. The choice of the most appropriate method of electrocardiogram (ECG) acquisition and QT/RR interval measurement in clinical trials requires better understanding of the differences among currently available approaches. This study compared standard and Holter‐derived 12‐lead ECGs for utility in detecting sotalol‐induced QT/QTc and RR changes. Manual methods (digitizing pad and digital on‐screen calipers) were compared for precision of QT and RR interval measurement. Methods and Results: Sixteen hundred pairs of serial 12‐lead digital ECGs were recorded simultaneously by standard resting ECG device and by continuous 12‐lead digital Holter over 3 days in 39 healthy male and female volunteers. No therapy was given on the 1st day followed by 160 mg and 320 mg of sotalol on the 2nd and 3rd day, respectively. Holter‐derived and standard ECGs produced nearly identical sotalol‐induced QT/QTc and RR changes from baseline, as did the manual digipad and on‐screen caliper measurements. The variability of on‐screen QT measurement in this study was greater than that of digipad. Conclusions: Digital 12‐lead Holter and standard 12‐lead ECG recorders, as well as the manual digitizing pad and digital on‐screen calipers, are of equal utility for the assessment of drug‐induced change from baseline in QT and RR interval, although the variability of the on‐screen method in this study was greater than of the digipad.     

Low prevalence of Brugada-type electrocardiogram in a prospective large cohort of Egyptians

BackgroundBrugada syndrome is a cardiac channelopathy that is associated with a high risk of VF and SCD and characterized by ECG pattern of transient or persistent, coved type ST-segment elevation in leads V₁–V₃.AimTo prospectively determine the prevalence of Brugada-type ECG pattern (Brugada sign) among unselected non cardiac individuals served at Cairo university teaching-hospital.MethodsThis study was conducted from October 2011 to September 2012, and included 4000 unselected noncardiac individuals (2078 males 52%, mean age 39 ± 14.44 years) admitted or presented to our hospital for different reasons. A 12-lead ECG was recorded for each of them; these ECGs were reviewed independently by two electrophysiologists for criteria of the three types of Brugada ECG pattern, and diagnosis of Brugada sign was made when both investigators agreed on the classification of the ECG findings according to the criteria of the Consensus Report of the Study Group of the Molecular Basis of Arrhythmia of the European Society of Cardiology.ResultsTwenty-two (0.55%) subjects had Brugada ECG pattern. All of them were of Mediterranean ethnic group. 18 males (0.45%), and 4 females (0.1%). No subjects showed type-1, while 11 (0.275%) of the 22 subjects had type-2, and the other 11 had type-3 Brugada ECG pattern. Eight cases (0.2%) among the 22 subjects were between 10 and 24 years old. Of the 22 subjects, 4 cases (18.2%) were symptomatic (palpitation and syncope), and 3 cases (13%) had positive F.H of SCD.ConclusionThe frequency of type-1 Brugada-type ECG pattern was 0%, while type-2 and type-3 (saddleback type) was 0.55% among Egyptian hospital-based population, and it was more prevalent in middle-aged males.     

Precordial low voltage in patients with ascites.

AIMS: Electrocardiographic (ECG) changes in patients with ascites are not well studied. The aim of this study was to evaluate ECG changes in patients with ascites. METHODS AND RESULTS: Prospective analysis of patients with ascites who were referred for paracentesis. Three ECGs were recorded before paracentesis. ECG 1 was a standard 12-lead ECG. For ECG 2 the precordial leads were placed 1 intercostal space (ICS) and for ECG 3, 2 ICS cranially. The sums (Sigma) of the QRS in ECG1 were compared with ECG 2 and 3. In six patients the same ECG protocol was performed after removal of ascites. Ten hospitalized patients without ascites served as controls. Twenty patients with ascites were analysed. Limbs leads low voltage was present in 11 patients and precordial low voltage in four patients. Cranial placement of the precordial electrodes increased SigmaQRS in all patients with ascites. The most prominent voltage changes appeared in the leads V4-V6 (+62%). Paracentesis of ascites normalized precordial leads low-voltage, while limbs leads low voltage remained. Cranial placement of the precordial electrodes in patients without ascites decreases SigmaV1-V6. CONCLUSION: We describe a phenomenon of precordial voltage changes in patients with ascites, not reported in the literature yet. By placing the precordial electrodes 1 and 2 ICS cranially the voltage changes can be 'corrected' and this should be done in all patients prior to further diagnostic workup. Removal of the ascites normalizes the precordial leads low voltage.     

Atrial electrophysiological abnormality in patients with Brugada syndrome assessed by P-wave signal-averaged ECG and programmed atrial stimulation.

BACKGROUND: There is evidence that some patients with Brugada syndrome (BS) exhibit atrial tachyarrhythmias including paroxysmal atrial fibrillation. We investigated whether BS associated not only with vulnerability to ventricular fibrillation, but also with vulnerability to atrial fibrillation. METHODS AND RESULTS: In 15 patients with BS and Brugada-type electrocardiogram (ECG) (14 men, 1 woman; age 52.8+/-12.9 years) and 15 age-matched control patients (12 men, 3 women; age 50.9+/-18.9 years), the P-wave signal-averaged ECG was recorded, and the filtered P-wave duration was derived from the vector magnitude obtained by X, Y, Z leads. In 11 of the 15 patients with BS and Brugada-type ECG, invasive electrophysiologic testing was conducted. Filtered P-wave duration was significantly increased in patients with BS and Brugada-type ECG in comparison with control subjects (143.2+/-12.9 vs 129.6+/-10.1 ms, p<0.001). Ventricular late potential (root mean square voltage <20 muV in the last 40 ms and <40 muV at a low amplitude signal duration >38 ms) was present in 10 of the 12 BS patients in whom a QRS wave signal-averaged electrogram was also recorded. In all 11 patients with Brugada-type ECG who underwent electrophysiologic testing, sustained atrial fibrillation (>5 min) was induced by 1 or 2 atrial extrastimuli. In 10 of these 11 patients, ventricular fibrillation was also induced by 2 or 3 right ventricular extrastimuli. CONCLUSIONS: The electrical abnormality in BS is not limited to the ventricular level; similar changes occur in the atria. Such abnormal conduction properties could be a substrate for re-entrant atrial tachyarrhythmias.     

Prevalence of right bundle-branch block and right precordial ST-segment elevation (Brugada-type electrocardiogram) in Japanese children.

BACKGROUND: The prevalence of Brugada-type electrocardiogram (ECG) in schoolchildren remains unclear. This study aimed to further investigate this condition. METHODS AND RESULTS: We studied the prevalence of Brugada-type ECG in 20,387 children (10,434 males and 9,953 females, 9.7 +/- 3.2 [SD] years old) during a school health examination in Kanagawa Prefecture, Japan, in 2002. We considered right bundle-branch block and ST-segment elevation of the J point of > or =0.1 mV in leads V1 through V3 as Brugada-like ECG, and an ECG was considered to be Brugada-type when the 12-lead ECG fully meet the criteria for the Brugada syndrome as recently published in a consensus report. Only 2 children (0.0098%, 95% confidence interval (CI): 0 to 0.023%) completely conformed to the criteria for Brugada-type ECG. Brugada-like ECG was found in 11 (10 male) of 20,387 children (0.054%, 95% CI: 0.022 to 0.086%). The prevalence in males was significantly higher than that in females, even in children (0.096% vs 0.010%, p=0.012). Stratified according to age, there was tendency for the prevalence of Brugada-like ECG to increase up to puberty (first graders, 0.01%; fourth graders, 0.05%; seventh graders, 0.08%; tenth graders, 0.23%; p=0.068). CONCLUSION: The prevalence of Brugada-type ECG in Japanese children was much lower than that reported in the adult population.     

Prevalence of drug-induced electrocardiographic pattern of the Brugada syndrome in a healthy population

To determine the prevalence of drug-induced Brugada's syndrome (BrS) electrocardiograms (ECGs) in a healthy population, a sodium channel blockade challenge was performed in previously identified subjects with BrS-compatible (BrC) ECGs. These subjects were detected in 1,000 normal patients in whom first ECGs were systematically recorded. Because of the intermittent nature of electrocardiographic modifications in BrS, second ECGs were also recorded in a representative sample of the population presenting with first ECGs with normal results. The prevalence of typical drug-induced BrS ECGs was 5 of the 1,000 patients. This value was fivefold greater than the reported prevalence of spontaneous BrS ECGs in the healthy population.     

Prevalência e Características Relacionadas de Pacientes com Eletrocardiograma com Padrão de Brugada em Santa Catarina,Brasil

Background:Brugada Syndrome is an inherited arrhythmogenic disorder characterized by the presence of specific electrocardiographic features with or without clinical symptoms. The patients present increased risk of sudden death due to ventricular fibrillation. The prevalence of this electrocardiographic pattern differs according to the studied region. However, epidemiological information including the Brazilian population is scarce.Objectives:To assess the prevalence of the electrocardiographic pattern of Brugada syndrome and the epidemiological profile associated with it.Methods:Cross-sectional study that included 846,533 ECG records of 716,973 patients from the electrocardiogram (ECG) database from the Santa Catarina Telemedicine Network over a 4-year period. All tests were 12-lead conventional ECG (without V1 and V2 in high positions). The tests revealing “Brugada Syndrome” diagnosis (Types 1 and 2) were reviewed by a cardiac electrophysiologist. The level of significance was set at p<0.05.Results:In total, 83 patients had a pattern potentially consistent with Brugada-type pattern ECG. Of these, 33 were confirmed having Brugada-type 1, and 22 with type 2 ECG after reevaluation. The prevalence of Brugada-type 1 ECG was 4.6 per 100,000 patients. Brugada-type 1 ECG was associated with the male gender (81.8% vs. 41.5%, p<0.001) and a lower prevalence of obesity diagnosis (9.1% vs. 26.4%, p=0.028).Conclusions:This study showed low prevalence of Brugada-type ECG in Southern Brazil. The presence of Brugada-type 1 ECG was associated with the male gender and lower prevalence of obesity diagnosis comparing to the general population.     

高位右侧胸前导联心电图在普罗帕酮激发试验中的价值

目的 报道10例疑诊Brugada综合征（BS）患者的普罗帕酮激发试验的结果，并探讨高位右侧胸前导联心电图在普罗帕酮激发试验中的价值。方法 对心室颤动（室颤）获救、晕厥或晕厥先兆者，以及无症状但有阳性猝死家族史者，经详细的病史询问、体格检查、心电图、X线胸片和超声心动图检查排除器质性心脏病，收集10例疑诊BS患者（观察组）。将同期因阵发性室上性心动过速行射频导管消融术、无器质性心脏病依据和猝死家族史的15例患者设为对照（对照组）。观察组与对照组均进行普罗帕酮激发试验。在普罗帕酮激发试验中同时描记常规12导联心电图与高位右侧胸前导联心电图。结果 观察组10例患者中普罗帕酮试验阳性者8例。常规与高位右侧胸前导联同时呈阳性改变者1例；常规导联阳性、高位右侧胸前导联阴性者3例；常规导联阴性或可疑、高位右侧胸前导联阳性者4例。若仅凭常规胸前导联心电图，阳性例数为4例，结合常规导联与高位右侧胸前导联心电图，阳性例数增加为8例。对照组无一例达阳性诊断标准。结论 普罗帕酮激发试验用于诊断Bs的敏感性与特异性均较好，加做高位右侧胸前导联心电图可提高诊断阳性率，且极为便捷。普罗帕酮试验中可考虑加做高位右侧胸前导联心电图，以避免漏诊。     

Body position effects on the ECG: Implication for ischemia monitoring

Rotation of the heart in relation to surface electrocardiographic (ECG) electrodes when a patient turns to one side has been reported to cause ST-segment shifts, triggering false alarms with continuous ST-segment monitoring. We prospectively analyzed ST-segment and QRS complex changes in both standard and derived ECGs in 40 subjects (18 with heart disease and 22 healthy) in supine, right- and left-lying positions. Of the 40 subjects, 6 (4 cardiac, 2 healthy) developed positional ST deviations of 1 mm or more on the standard ECG. In the derived method, five of the same six subjects showed ST-segment deviation of which most occurred in the left-lying position. Positional ST changes were most frequent for males and for cardiac patients (33%). Changes in QRS complex morphology were common on the standard (28 of 40, 70%) and less frequent on the derived ECGs (17 of 40, 43%), occurring in both healthy and cardiac subjects. QRS axis changes occurred only on the standard ECG. It was concluded that (1) right and left side-lying positions frequently induce clinically significant ECG changes; (2) positional ST-segment deviation is less frequent than previously reported and is most likely to occur in males with cardiac disease; and (3) the derived method is less prone to positional QRS changes than the standard ECG.     

Prognosis of subjects with Brugada-type electrocardiogram in a population of middle-aged Japanese diagnosed during a health examination

There is controversy about the clinical significance of an incidental finding of a Brugada-type electrocardiogram (ECG) pattern. To assess the prognosis of subjects with a diagnosis of a Brugada-type ECG pattern during a health examination, 13,904 subjects (mean age 58 +/- 10 years) who had the annual health examination including an ECG offered to adult citizens of Moriguchi City, Osaka, Japan, in 1997 were studied. A Brugada-type ECG pattern was found in 98 subjects, and 37 subjects had type 1. During a mean follow-up of 7.8 +/- 1.6 years, there were 4 deaths (4.1%) and 1 cardiovascular death (1.0%) in subjects with a Brugada-type ECG pattern, whereas there were 612 deaths (4.4%) and 142 cardiovascular deaths (1.0%) in those without. One cardiovascular death in a subject with a Brugada-type ECG pattern was sudden death. Unadjusted proportional hazards regression analyses showed that Brugada-type ECG pattern was not associated with either all-cause (hazard ratio [HR] 0.90, 95% confidence interval [CI] 0.34 to 2.41) or cardiovascular mortality (HR 0.97, 95% CI 0.14 to 6.93). After adjustment for cardiovascular risk factors, Brugada-type ECG pattern had no association with either all-cause (HR 0.77, 95% CI 0.29 to 2.07) or cardiovascular mortality (HR 1.01, 95% CI 0.14 to 7.31). In conclusion, Brugada-type ECG patterns diagnosed during a health examination in a middle-aged population had a low risk of sudden death and were not associated with increased risk of either cardiovascular or all-cause mortality.