Diagnosis of Arrhythmogenic Right Ventricular Dysplasia‐Cardiomyopathy: Value of Standard ECG Revisited

Background: The diagnostic dilemma in arrhythmogenic right ventricular dysplasia‐cardiomyopathy (ARVD/C) is that a single diagnostic test does not exist and that there is a need for broadening diagnostic criteria. As standard ECG contributes significantly to clinical diagnosis and represents a tool for screening in family studies ECG data should be revisited. Methods and Results: In a cohort of 265 patients (159 males, mean age 46.8 years) with ISFC/ESC criteria of ARVD/C ECG features were reevaluated. QRS duration in (V1 + V2 + V3)/(V4 + V5 + V6) ≥ 1.2—called localized right precordial QRS prolongation—was present in 261/265 patients (98%) and represents the essential finding. Right precordial epsilon potentials were found in 23% in standard and in 75% in highly amplified and modified recording technique. Right precordial T wave inversions were present in 143 cases (54%) and ST‐segment elevation of different types in 66 patients (25%). Localized prolongation of inferior QRS complexes could be found in 58 cases (22%), complete right bundle branch block with T inversions beyond V2 in most cases in 17 patients (6%), incomplete right bundle branch block in 38 cases (14%), pseudo‐incomplete right bundle branch block in 8 patients (3%), and right precordial R wave reduction in 14 cases (5%). Conclusion: With regard to sensitivity and already known specificity an ECG score for the diagnosis of ARVD/C was developed with high probability of ARVD/C in cases with ≥4 points, possibly without the need for an additional imaging technique. Standard ECG with additional highly amplified and modified recording technique represents a single diagnostic test with high value in the clinical diagnosis of ARVD/C and should be used as a first line tool in noninvasive family screening.           A.N.E. 2003; 8(3):238‐245     

The value of different electrocardiographic depolarization criteria in the diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy

Background

The use of electrocardiographic (ECG) depolarization and repolarization criteria plays a large role in the diagnosis of arrhythmogenic right ventricular dysplasia/cardiomyopathy (ARVD/C). Different ECG algorithms should be analyzed in making the diagnosis of ARVD/C with the use of normal and modified recording techniques.

Methods

In a cohort of 343 patients (210 men and 133 women; mean age, 46.0 ± 13.7 years) meeting the Task Force of the Working Group on Myocardial and Pericardial Diseases of the European Society of Cardiology and the Scientific Council on Cardiomyopathies of the International Society and Federation of Cardiology diagnostic criteria for ARVD/C, the value of different ECG criteria (eg, localized right precordial QRS prolongation defined as QRS duration in (V1+V2+V3)/(V4+V5+V6) of 1.2 or higher, right precordial QRS prolongation with QRS in V1-3 of 110 milliseconds or higher, epsilon potentials in the right precordial leads, S-wave upstroke in V1-3 of 55 milliseconds or higher, and right precordial T-wave inversions) was analyzed with the use of a normal recording technique and a highly amplified and modified recording technique (n = 207) at a paper speed of 50 mm/s. Fifty-two phenotypically and genotypically unaffected individuals identified by systematic screening in 24 families (30 men; mean age, 42.4 ± 8.3 years) were treated as control subjects.

Results

In the normal as well as highly amplified and modified recording techniques, the incidence of localized right precordial QRS prolongation was 98% (100%), that of QRS in V1-3 of 110 milliseconds or higher was 75% (80%), that of prolonged right precordial S-wave upstroke was 84% (60%), that of epsilon potentials was 23% (77%), and that of right precordial T-wave inversions was 55%. Four of 6 patients without the phenomenon of localized right precordial QRS prolongation with the use of the normal recording technique had a prolonged S-wave upstroke of 55 milliseconds or higher. In the control group, localized right precordial QRS prolongation, QRS in V1-3 of 110 milliseconds or higher, and epsilon potentials could not be identified. An S-wave upstroke of 55 milliseconds or higher was present in 2 of 3 cases, and T-wave inversions were found in 3.

Conclusions

Electrocardiographic depolarization criteria for ARVD/C analyzed in this large cohort of patients meeting the International Society and Federation of Cardiology/European Society of Cardiology criteria presented with high sensitivity and specificity in comparison with those in the control group of phenotypically and genotypically unaffected individuals defined by systematic screening in 24 families with ARVD/C. The incidence of right precordial T-wave inversions was much lower, indicating that not only patients with overt right ventricular dilatation and dysfunction were included. Electrocardiographic algorithms, including localized right precordial QRS prolongation, prolonged S-wave upstroke, and epsilon potentials, with the use of the normal recording technique and the amplified and modified recording technique at a paper speed of 50 mm/s contribute significantly to the noninvasive diagnosis of ARVD/C.     

致心律失常性右室心肌病高危患者相关危险因素分析

目的探讨致心律失常性右室心肌病(ARVD/C)高危患者相关危险因素。方法根据1994年ARVD/C诊断标准,纳入43例ARVD/C先证者。分组标准:有晕厥病史并记录到室性心动过速(简称室速)为高危病人;记录到室性早搏(简称室早)、室速但无晕厥病史及其他临床情况定为低危病人。收集参数包括:①心电图V1～3QRS波时限≥110 ms、V1～3导联S波升支时限≥55 ms、Epsilon波、T波倒置、(V1+V2+V3)/(V4+V5+V6)QRS波时限≥1.2、QRS波离散度≥40 ms、QT离散度≥65 ms;②信号平均心电图记录晚电位参数;③Holter记录室早或室速;④超声记录双房、双室及右室流出道、流入道内径大小。Logistic回归分析高危患者ARVD/C病人的相关危险因素。结果心室晚电位阳性、右室射血分数<0.40与高危ARVD/C显著相关。结论晚电位阳性、右心功能不全是ARVD/C的高危因素。     

Conventional Electrocardiogram in Arrhythmogenic Right Ventricular Dysplasia-Cardiomyopathy and Idiopathic Right Ventricular Outflow Tract Tachycardia

Objective: Arrhythmogenic right ventricular dysplasia up to now is a rare cardiomyopathic entity with certain difficulties in clinical definition of diagnostic criteria. In 42 patients with major and minor criteria of arrhythmogenic right ventricular dysplasia and 25 patients with idiopathic ventricular arrhythmia, the role of conventional ECG in the diagnosis of arrhythmogenic right ventricular dysplasia was reevaluated. Methods: In standard 12-lead ECG, QRS duration was measured in limb lead D₁, and in V₁-V₆. A ratio of the sum of right (V₂+ V₃) and left (V₄+ V₅) was calculated. T wave inversions, Epsilon wave, and mechanisms of advancing right bundle branch block were analyzed. Results: In 39 out of 42 patients (93%) with the diagnosis of arrhythmogenic right ventricular dysplasia, a ratio of right and left precordial QRS duration of >1.2, a maximum right precordial QRS duration of > 100 ms in 10 cases (26%) and >110 ms in 29 cases (74%) could be found. Incomplete right bundle branch block with right precordial T inversions was found in one case. The ECG in two patients revealed a precordial R/S transition in V₁ or V₂; in all other cases, R/S transition was localized in V₃ or V₄. R peak time was normal (< 0.04 s) in all cases, a “notching” or “slurring” of the S wave was striking in 16 cases. T wave inversions were found in 27 cases and definite Epsilon wave in only one case. Although incomplete right bundle branch block and certain preforms could also be disclosed in four patients with idiopathic right ventricular outflow tract (RVOT) tachycardia, localized right precordial QRS prolongation could be excluded in all but one of these cases. Localized right precordial QRS duration prolongation in one case was probably due to a rotation of the heart with a precordial R/S transition between V₁ and V₂. Conclusion: Localized right precordial QRS prolongation in a normal precordial R/S transition: (a) seems to be the most important aspect of arrhythmogenic right ventricular dysplasia at conventional ECG, with a sensitivity of 93% and a specificity of 96% in order to distinguish idiopathic RVOT tachycardia; (b) can appear with (64%) or without (36%) secondary T wave inversions; and (c) is due to a “parietal” block sparing the specialized conducting system.     

36例致心律失常性右室心肌病的心电图特征和临床观察

目的探讨致心律失常性右室心肌病(ARVC)的心电图特征和临床表现。方法回顾分析符合欧洲心脏病协会ARVC诊断标准的36例患者的心电图参数、临床表现、超声心动图、腔内电生理检查等临床资料。结果36例中男26例、女10例,年龄37±13岁;33例表现为心悸、胸闷,11例同时伴有晕厥,2例有家族性猝死史。心电图研究发现10例(28%)出现Epsilon波,29例(81%)右胸(V1～V3)导联QRS波时限≥110ms;在29例无右束支传导阻滞的患者中,右胸导联分别有16例(55%)出现T波倒置、18例(62%)出现S波升支时间≥55ms;17例(47%)QRSd1/QRSd2(V1～V3导联与V4～V6导联QRS波时间平均值之比)≥1.2;24例(67%)出现室壁阻滞;27例(75%)记录到持续性或非持续性室性心动过速。29例超声心动图表现为严重的右室受累。25例行腔内电生理检查,20例诱发出右室起源的室性心动过速,即刻射频消融成功11例。结论ARVC好发于青年男性,是引起晕厥、室性心律失常和室壁运动异常的重要原因,Epsilon波、右胸导联QRS波时限≥110ms与T波倒置、右室起源的室性心律失常为其特征性的心电图改变,QRSd1/QRSd2≥1.2、室壁阻滞、右胸导联S波升支时间≥55ms有助于该病的诊断,经导管射频消融治疗室性心动过速成功率低。     

家族史在致心律失常性右心室心肌病危险分层中的地位

目的 探讨家族史在致心律失常性右心室心肌病(ARVC)危险分层中的地位.方法 根据1994年ARVC诊断标准,纳入34例ARVC先证者,男性26例,女性8例,平均年龄(38±15)岁.对其家族成员行临床筛查,项目包括:(1)心电图V1～V3导联QRS≥110 ms、V1～V3导联S波升支≥55 ms、Epsilon波、T波倒置(V1～V3导联倒置)、(V1+V2+V3)/(V4+V5+V6)QRS≥1.2、V1～V3导联与V6导联QRS差值≥25 ms,QRS离散度≥40 ms,QT离散度≥65 ms;(2)动态心电图记录室性早搏≥2000个/24 h或室性心动过速(VT);(3)超声心动图记录双心房、双心室及右心室流出道、流人道内径大小.比较ARVC家族史和上述各项临床参数的关系.分类变量用Fisher检验,连续变量使用t检验.P≤0.05为差异有统计学意义.结果 34例ARVC先证者中55个家族成员接受评估,男性28例(6例诊断ARVC)、女性27例(3例诊断ARVC),平均年龄(35±16)岁.8例先证者有家庭成员受累,其中5例有左束支阻滞形室性心动过速(LBBB-VT,63%);26例先证者家庭成员无受累,其中20例有LBBB-VT(77%),P=0.649.家族史和室性心动过速的发生筹异无统计学意义.结论 家族史并不能反映ARVC的危险程度.     

Special features of right bundle branch block in patients with arrhythmogenic right ventricular cardiomyopathy/dysplasia

We searched for special features in patients with complete and incomplete right bundle branch block diagnosed as having arrhythmogenic right ventricular cardiomyopathy/dysplasia. Whether right bundle branch block is a frequent finding in arrhythmogenic right ventricular cardiomyopathy should be studied. The question is whether special features exist such as T-wave inversions, localized right precordial QRS prolongation and r'/s ratio<1. RESULTS: ARVC could be diagnosed according to ISFC/ESC criteria in 374 patients. CRBBB was found in 22 cases (6%) and iCRBBB was present in 47 cases (12.5%). In CRBBB T wave inversions ≥ V4 was found in 10 cases (n.s.) and r'/s ratio<1 was present in 12 cases (p<0.001). In iCRBBB T wave inversions ≥ V4 was found in 10 cases (n.s.) and ST segment elevation in right precordial leads was present in 19 cases (p<0.005). In all patients with ARVC localized right precordial QRS prolongation was found. Patients with CRBBB have a bad prognosis: 17 of 22 patients developed biventricular heart failure requiring heart transplantation and diuretic therapy. CONCLUSIONS: CRBBB and iCRBBB are infrequent findings in arrhythmogenic right ventricular cardiomyopathy. Complete right bundle branch block is characterized by r'/s ratio<1. There are no significant T wave inversions ≥ V4. Incomplete right bundle branch block is characterized by ST segment elevation in right precordial leads but not by T wave inversions ≥ V4.     

An unusual bundle-branch block

We report a case of right bundle-branch block (RBBB) showing a QRS configuration typical for left bundle-branch block (LBBB) in leads V(5) and V(6). The QRS axis was at +90 degrees, and the QRS duration was 0.14 second. There were wide S waves in leads I and aVL, suggesting at first glance an RBBB, but the QRS morphology in the inferior leads (monophasic R wave with secondary ST-T changes) was more consistent with an LBBB. Lead V(1) suggested an RBBB, whereas leads V(5) and V(6) showed a monophasic R wave as in LBBB; moreover, a negative T wave, typical of LBBB, was present in lead V(5). Placement of the electrodes of leads V(4), V(5), and V(6) 2 intercostal spaces above restored in these leads a QRS configuration suggestive of RBBB. The diagnostic problem was mainly caused by the inferior direction of the QRS axis. Because the electrode of V(6) is normally placed below the electrical center of the heart, namely, on a plane that is not orthogonal to the sagittal plane, a vector directed mainly inferiorly and slightly to the right does not project on the negative part but on the positive of the lead line. For this reason, the S waves normally observed in the left precordial leads with RBBB disappear. The superior displacement of the electrodes "normalizes" the plane upon which the lead lines lie, thereby restoring the expected QRS configuration.     

致心律失常性右心室心肌病的心电图特征

目的探讨国人致心律失常性右心室心肌病患者临床心电图特征。方法分析32例致心律失常性右心室心肌病患者体表心电图各项参数。结果心电图记录到Epsilon波12例,QRS时间（V1＋V2＋V3）／（V4＋V5＋V6）≥1.2共15例,终末激动时间延长17例,出现QRS波群碎裂23例,可见异常Q波8例,V1～V3T波倒置且不存在束支传导阻滞14例,完全性右束支传导阻滞3例,不完全性右束支传导阻滞1例。28例记录到室性心动过速。结论Epsilon波、QRS时间（V1＋V2＋V3）／（V4＋V5＋V6）≥1.2、终末激动时间延长≥55ms及QRS波群碎裂是致心律失常性右心室心肌病特征性的体表心电图改变。     

The electrocardiogram of the normal child

The EKG findings of 202 normal children, aged 1 month to 10 years were reviewed in order to determine criteria for diagnosis of ventricular hypertrophy. QRS voltage in right and left precordial leads are very variable and do not constitute adequate criteria for the diagnosis of ventricular hypertrophy the same is true with QRS duration, which increases progressively from 50 to 60 msec from the first to the fourth year of life, and to 70 msec over that age. The values found are smaller than those previously reported in the literature. Measurement of initial intrinsicoid deflection time in leads VI, aVF and V6 apparently have important clinical significance. This is a constant finding in normal hearts in lead VI, where deflection time is 18 to 20 msec. Therefore, times above 25 to 30 msec are sugestive of right ventricular hypertrophy when RBBB is not present. Intrinsicoid deflection time in lead V6 in children under one year of age was 20 msec, while between age one and ten it varied between 20 and 31 msec. Such variations show how left ventricular tissue increases after the first years of life, and also that times above 5 msec over those found for any age group are indicative of left ventricular hypertrophy.     

An electrocardiographic algorithm for determining the location of pacemaker electrode in patients with right bundle branch block configuration during permanent ventricular pacing

The expected morphology of right ventricular pacing is a left bundle branch block (LBBB) pattern. However, right bundle branch block (RBBB) can also be seen during permanent right ventricular pacing. The aim of this study was to develop an electrocardiographic algorithm to differentiate this benign condition from septal and free wall perforation with subsequent left ventricular pacing. Three hundred consecutive patients who had permanent ventricular or dual-chamber pacemaker implantation between 1999 and 2000 were screened and 25 patients (8.3%) who exhibited RBBB configuration were included in the study. Echocardiograms and chest radiographs were evaluated in order to identify the pacing lead location in this group. The authors formed a study group with their own 25 patients and 22 cases of RBBB with permanent pacemaker from previous publications (total 47 patients). Frontal axis, QRS morphology in lead V(1), and the precordial transition point, which is defined as the precordial lead where R wave amplitude is equal to S wave amplitude, were examined. Placement of precordial leads V(1) and V(2) 1 interspace lower than the standard location (Klein maneuver) eliminated the RBBB pattern in 12 patients. RBBB pattern with "true right ventricular pacing" was detected in 24 of the 25 patients, and in 11 of the 22 patients reported in the literature (total 35 patients). Right ventricular pacing was correctly identified in 34 of 35 patients with use of criteria including left superior axis deviation, RS or qR morphology in lead V(1), and precordial transition at lead V(3) with a high sensitivity and specificity. A simple surface electrocardiogram can accurately predict the lead location in patients having RBBB morphology with right ventricular pacing.     

Changing electrocardiographic findings in pulmonary embolism in relation to vascular obstruction

Electrocardiographic (ECG) findings in 87 consecutive patients with from minor to massive pulmonary embolism are presented. ECG changes suggestive of acute right ventricular strain defined as the occurrence of complete (c) or incomplete (inc) right bundle branch block (RBBB), an SIQIIITIII pattern, inverted T waves in the second and third precordial leads and/or an increase in the frontal QRS axis of 20 degrees C or more were found in 71 patients (82%). The prevalence of c and inc RBBB and the increase in frontal QRS axis correlated with the extent of embolization (angiographic or scintigraphic score), while the appearance of the SIQIIITIII pattern did not. No patient with a vascular obstruction of two thirds or more had an ECG free of signs of right ventricular strain. In 9 of 11 embolectomized patients with c RBBB, c RBBB disappeared within 24 h postoperatively. Among patients with an embolization of 45% or more, those with c RBBB had a shorter symptom duration, fewer embolic episodes and a lower pulmonary artery pressure than those without c RBBB. As ECG abnormalities were transient and changing in nature, serial ECG recordings are recommended. Pronounced ECG signs of right ventricular strain should, as they may reflect both massive and short-lasting vascular obstruction, arouse the suspicion of pulmonary embolism suitable for embolectomy.     

The anterior displacement of the QRS loop as a right ventricular conduction disturbance. Electrophysiologic and vectorcardiographic study in man

Anterior displacement (AD) of the QRS horizontal loop (Frank VCG method) was induced by programmed right atrial stimulation (PRAS) in 15 cases. When AD occurred we noticed changes of the terminal QRS vectors and of the T loop similar to those observed in incomplete right bundle branch block (RBBB). The increasingly anticipated extrastimuli induced progressively the AD and then progressive degrees of RBBB. The anterior shifting of the efferent limb never appeared after the induction of RBBB. A left conduction disturbance never appeared after the AD. In cases of supposed incomplete left bundle branch block (i.e. left ventricular hypertrophy) the QRS duration decreased when the AD was induced. Therefore, the AD induced by PRAS and probably those observed in some clinical cases are due to a right ventricular conduction disturbance.     

ECG Features that suggest a potentially life-threatening arrhythmia as the cause for syncope

Syncope is a risk factor for sudden cardiac death (SCD) in many conditions associated with structural heart disease as well as inherited heart disease. The ECG in patients with syncope should be examined carefully for signs of structural heart disease, such as myocardial infarction or cardiomyopathy; signs of conduction system disease, such as bundle branch block or atrioventricular block; and signs of primary electrical disease. Important forms of cardiomyopathy accompanied by ECG changes include hypertrophic cardiomyopathy (HCM), and arrhythmogenic right ventricular dysplasia (ARVD/C). Common ECG findings in HCM include left ventricular hypertrophy by voltage, repolarization abnormalities, QRS widening, pseudoinfarction patterns, and slurred QRS upstroke mimicking delta waves. Classical ECG findings of ARVD/C include T-wave inversions and epsilon waves in the right precordial leads (V₁–V₃). Important forms of primary electrical disease which may result in syncope include Wolff–Parkinson–White syndrome, long QT syndrome, and Brugada syndrome, which is characterized by coved ST-segments in the right precordial leads, associated with a history of syncope, ventricular arrhythmia, or sudden cardiac death in probands or family member. There are three Brugada ECG patterns; however, only type I (spontaneous or induced) is considered diagnostic. Recently, studies have suggested that patients with J-point elevation or early repolarization pattern on ECG are at elevated risk of SCD. The clinical significance of finding early repolarization in a patient with syncope is unknown and should be a subject of future research.     

Risk stratification of sudden cardiac death and malignant ventricular arrhythmias in right ventricular dysplasia-cardiomyopathy

Arrhythmogenic right ventricular dysplasia-cardiomyopathy is in most cases a benign cause of ventricular arrhythmias in young patients. The major reason of mortality is sudden arrhythmic death with an annual rate of 2-3% as the first manifestation of the disease in most cases. Little is known about risk factors of sudden arrhythmic death so far. The purpose of the retrospective study was to classify risk factors from invasive and non-invasive examinations. METHODS: In a cohort of 121 consecutive patients sampled from 1986 to 1998 the value of right ventricular dilatation, left ventricular involvement analysed by angiocardiography or echocardiography and standard ECG parameters such as precordial T wave inversions, right precordial ST elevation, precordial QRS dispersion, left precordial JT interval prolongation and complete right bundle branch block were determined. The whole cohort of patients were divided into two groups with high arrhythmic risk (aborted or non-aborted sudden death, recurrent ventricular tachycardia despite medical treatment, recurrent syncopes) and low risk (frequent ventricular premature beats, non sustained ventricular tachycardia, uneventful course under medical therapy). RESULTS: From angiocardiography or echocardiography in a quantitative approach right ventricular dilatation (p<0.0001) and additional left ventricular abnormalities (p<0.0001) could be identified as major risk factors. From an ECG point of view increased precordial QRS dispersion > or =50 ms (p<0.01) with complete right bundle branch block and right ventricular dilatation in most cases and precordial T wave inversions beyond V3 (p<0.0001) and the phenomenon of left precordial JT interval prolongation (JT dispersion > or =30 ms) in cases of additional left ventricular abnormalities represented non-invasive predictors of recurrent arrhythmic events. Right precordial ST segment elevation could be excluded as risk factor of sudden arrhythmic death. CONCLUSIONS: Right ventricular dilatation with ECG depolarisation abnormalities and additional left ventricular involvement with striking ECG repolarisation abnormalities could be identified as strong risk factors of recurrent arrhythmic events in ARVD with unfavorable prognosis.     

Effect of Right Bundle Branch Block on Electrocardiographic Amplitudes,Including Combined Voltage Criteria Used for the Detection of Left Ventricular Hypertrophy

Background: Although right bundle branch block (RBBB) delays right ventricular depolarization, its effect on cancellation of right and left ventricular forces within the QRS complex has not been quantified during stable temporal and physiological conditions. Systematic changes in QRS amplitude during transient RBBB bear directly on performance of standard ECG criteria for left ventricular hypertrophy (LVH), and these changes require quantification. Methods: We examined the instantaneous effect of RBBB on QRS amplitudes and LVH voltages in 40 patients who had intermittent complete RBBB during a single 10 sec standard 12‐lead ECG recording, comprising 0.1% of approximately 400,000 consecutive ECGs in a university teaching hospital setting. Amplitudes were measured by magnifying graticule to the nearest 25 microvolts, averaged for up to 3 normal and 3 RBBB complexes, and compared by paired t test. Results: RBBB was associated with an increase in initial QRS forces (RV1, RV2, and QV6) but significant decreases in mean mid‐QRS amplitudes that reflect left ventricular depolarization (RaVL [−75 microvolts], SV1 [−389 microvolts], SV3 [−617 microvolts], RV5 [−100 microvolts], and RV6 [−123 microvolts]). All late QRS forces were increased with RBBB (R'V1, SV5, SI). As a result, combined voltages used for LVH criteria were significantly reduced by RBBB: Sokolow‐Lyon voltage decreased from 1520 ± 739 to 1014 ± 512 microvolts (p < 0.001) , and Cornell voltage decreased from 1438 ± 683 to 746 ± 399 microvolts (p < 0.001) . Conclusions: RBBB is associated with significant reduction in "left ventricular" QRS amplitudes of the standard ECG, consistent with cancellation, rather than unmasking, of left ventricular mid‐QRS forces by altered septal and delayed right ventricular depolarization. Because QRS voltages that are routinely combined for the detection of LVH are reduced in RBBB, standard LVH criteria will perform with lower sensitivity in patients with RBBB.     

致心律失常性右室发育不良或心肌病15例的临床特点及疗效

目的 探讨致心律失常性右室发育不良或心肌病(ARVD/C)的临床特点及分析疗效。方法 分析2000～2007年诊断为ARVD/C 15例入院病例资料,对其临床特点作统计分析,并探讨治疗方法及疗效。结果 在ARVD/C 15例病例中(7男),年龄为13～61(31±12)岁,首发症状年龄为10～51(28±11)岁;3例有家族史;6例(40%)有晕厥发作史;5例(33%)患者仅有心悸症状;1例常规心电图检查中发现Epsilon波,见于右侧胸导联V2～3,伴有T波倒置;13例(87%)超声心动图结果异常,主要为RV扩大;4例行心脏磁共振（MRI）检查:见右室壁脂肪信号2例,右室壁变薄3例,右心室扩大3例;有症状的室性心律失常患者接受胺碘酮、β阻滞剂或采用其他抗心律失常药物治疗,但47%的患者(7/15)应用抗心律失常药物治疗无效,3例患者接受射频消融治疗,其中有1例患者出现室性心动过速复发。4例患者植入植入式心脏自动复律除颤器 (ICD),其中1例因多次自动除颤,电池耗竭,而更换ICD。结论 ARVD/C以室性心律失常为主要表现,诊断依靠家族史、晕厥发作史、ECG、超声心动图、MRI。抗心律失常药物的疗效较差,射频消融或植入ICD可治疗致命性心律失常,减少猝死的发生。     

左束支起搏心电图的特点观察

目的通过比较自身心律、左束支起搏、右室心尖部或右室流出道起搏时心电图的形态和QRS波群时限等,找寻左束支起搏心电图的特征表现。方法选取拟行左束支起搏42例患者,记录标准12导联体表心电图,通过测量,分别比较自身心律、左束支起搏及右室心尖部/右室流出道起搏时QRS波群时限、电轴、形态及ST段的差异。结果自身心律与左束支起搏相比,QRS波群时限无统计学差异(P=0. 49),但与右室心尖部/右室流出道起搏相比,具有显著差异(P <0. 000)。左束支起搏组,V1导联呈特征性"M"或"r SR"的比例为76. 19%;a VR导联亦可呈特征性"M"或"r SR"表现,比例为78. 57%。对于自身心律为右束支阻滞者,左束支区域起搏仅V1导联呈"M"或"r SR",a VR导联呈QS型,而无特征性"M"或"r SR"表现。与经典的右束支阻滞心电图比较:左束支起搏ST段和T波改变无规律性。结论左束支起搏心电图QRS波群时限和电轴与自身心律相比无显著差别,V1及a VR导联均可见特征性"M"或"r SR"表现,右束支阻滞患者仅V1导联呈特征性表现,但依靠心电图的特征性"M"或"r SR"改变判断起搏位点有局限性。     

Right precordial ST and QRS changes in the diagnosis of right ventricular infarction

Two groups of patients with anatomically proved acute myocardial infarction were compared in order to study specificity and sensitivity of the ECG criteria previously described in clinical and experimental right ventricular infarction ( RVI ). Group 1 included 21 patients with left inferior infarction and with a variable degree of right ventricular involvement; group 2 included nine patients with myocardial infarction confined to the left inferior wall. In both groups the presence of ST elevation (at least 0.05 mV) and the morphology of the QRS complex in V4R , V3R, and V1 were assessed in ECGs performed at the time of admission. Also, in order to evaluate the morphology of the ST segment and QRS complex in right precordial leads in normal subjects, an ECG with 12 standard and four right precordial leads ( V6R to V3R) was performed in 82 subjects (group 3) without clinical and ECG evidence of heart disease. Our data reveal that in normal subjects an rS pattern is always present in V3R and frequently (91%) in V4R . On the contrary, the presence of QS or QR complexes in both V4R and V3R are specific markers of right ventricular necrosis (specificity 100%; sensitivity 78%). The presence of injury and necrosis waves in V4R or V4R to V3R during inferior infarction is a useful diagnostic criterion in that it insures a highly specific diagnosis of acute RVI in the great majority (76 and 71%, respectively) of the cases with autopsy evidence of right ventricular involvement.