T wave changes in the right precordial leads in seven-and eight-year-old children during a Valsalva manoeuvre

The T waves in the right precordial leads were analyzed in 106 eight-year-old and 90 seven-year-old unselected healthy children. Recordings during relaxation were compared with those obtained during a Valsalva manoeuvre. In the relaxed state only three children in each age group showed a positive T wave in lead V1, while during the Valsalva manoeuvre 90 of the 106 eight-year-old and 55 of the 90 seven-year-old children converted to a positive T V1. The difference is highly significant in both age groups and both sexes (p much less than 0.001). Minor changes towards more positive T V2 and T V4 were also found.     

Electrovectorcardiographic study of negative T waves on precordial leads in arrhythmogenic right ventricular dysplasia: relationship with right ventricular volumes

In 24 cases of arrhythmogenic right ventricular (RV) dysplasia, the electrovectorcardiographic (ECG-VCG) behavior of T horizontal (wave and loop) was analyzed and the data compared with RV angiographic volumes. Arrhythmogenic RV dysplasia was diagnosed on the basis of echocardiographic and angiographic data in all subjects. At ECG, T wave was negative in V1 in nine subjects (37%), in V1-V2 in six (25%), in V1-V3 in two (8%), in V1-V4 in one (4%), in V1-V5 in two (8%), and in V1-V6 in four (16%). Nine subjects (37%) presented a bifid T wave in V2-V4. At VCG, T horizontal loop showed three morphologic characteristics: (1) counterclockwise rotation with a mean axis range of +15 degrees to -10 degrees (average, +5 degrees); (2) a figure-eight pattern with a mean axis range of +10 degrees to -40 degrees (average, -17 degrees); and (3) clockwise rotation with a mean axis range of -40 degrees to -110 degrees (average, -70 degrees). T wave changes seem to be primary and independent from QRS changes. RV and diastolic volumes ranged from 100 to 320 m1/m2 (average, 169 +/- 69). The extension of T wave negativity on precordial leads has a direct relationship with RV enlargement (r = 0.89, p less than 0.01). T changes are probably caused by dislocation of the left ventricle backwards secondary to RV dilatation, asynchronous RV repolarization, or intraparietal RV conduction defects.     

正常人右胸导联心电图P波形态及性别差异

目的 探讨正常人右胸导联心电图男女P波形态差异及变化规律.方法 测量900名正常人右胸导联心电图,男女对半,分析P波形态及变化规律.结果 右胸导联心电图P波以直立和正负双相P波为主.V1导联直立P波的发生率明显多于正负双相P波的发生率(P<0.01).从V1～V6R直立P波的发生率依次减少,正负双相P波的发生率依次增多...     

正常人右胸导联心电图T波形态的性别差异

目的探讨正常人右胸导联心电图男女T波形态差异规律及临床意义。方法测量240名正常人右胸导联心电图,比较男女T波形态及变化规律。结果Vl→V3R→V6R直立T波出现率逐渐减少,倒置T波出现率逐渐增多。女性以倒置T波为主,男性以直立T波多见,差异有显著意义(P<0.01)。V1→V6R的T波变化规律:可均倒置,女性多于男性(P<0.01);也可由直立→双相→平坦→倒置,男性多于女性(P<0.01),但未见由倒置→直立。结论正常人右胸导联心电图T波形态男女差异显著,应引起临床注意。     

胸导联R波递增不良的临床意义

目的探讨胸导联R波递增不良的临床意义。方法对92例胸导联R波递增不良患者的心电图表现作临床回顾性分析。结果92例中69例（A组）明确有器质性疾病，23例（B组）无明显器质性疾病。A组胸导联符合R／S比例自右至左逐渐增高者5例（7．2％）低于B组20例（87．0％），差异有非常显著性意义（P〈0．01）。Rv1～Rv3均小于0．3mV者，A组（61例，88．4％）高于B组（2例，8．7％），差异也有非常显著性意义（P〈0．01）。结论胸导联R波递增不良可由多种器质性胸心疾病或生理性改变等原因引起，要密切结合临床加以判断。     

Clinical implication of left precordial T wave inversions in the presence of complete right bundle branch block

This study was designed to elucidate whether left precordial negative T waves are electrocardiographic indicators for the diagnosis of hypertrophic cardiomyopathy (HCM) even in the presence of complete right bundle branch block (CRBBB). In 7 consecutive patients with CRBBB accompanied by negative T waves in at least one of the left precordial leads (V4, V5, V6, maximal negativity; 1.06 +/- 0.40 mVol) (left precordial negative T wave group) and in 15 randomly selected CRBBB patients without left precordial T wave inversions (control group), echocardiography was performed to rule out underlying diseases causing left ventricular overload and to identify candidates for magnetic resonance (MR) imaging. None had anginal pain indicating ischemic heart disease. When 2-dimensional echocardiography indicated left ventricular hypertrophy with wall thickness > or = 15 mm, the magnitude and distribution of hypertrophy were scrutinized on contiguous left ventricular MR short-axis images. The diagnostic criterion of HCM was the demonstration of hypertrophy with a wall thickness of 20 mm or more on the left ventricular MR short-axis images. All patients in the left precordial negative T wave group had negative T waves in both I (negativity; 0.27 +/- 0.17 mVol) and aVL (negativity; 0.23 +/- 0.14 mVol), whereas none in the control group did. The diagnostic criterion for HCM was fulfilled in six patients in the left precordial negative T wave group. However there were no patients who fulfilled the criterion in the control group. Negative T waves were recorded in the I (negativity; 0.30 +/- 0.17 mVol), aVL (negativity; 0.25 +/- 0.14 mVol), V4 (negativity; 1.03 +/- 0.46 mVol), V5 (negativity; 0.83 +/- 0.37 mVol) and V6 leads (negativity; 0.31 +/- 0.31 mVol) in all patients with HCM, while they were recorded in only 6% of the patients without HCM. In conclusion, the existence of left precordial negative T waves in the presence of CRBBB strongly indicates HCM.     

双峰T波与先天性心脏病

目的探讨先天性心脏病及正常人群组双峰T波的检出率差异性,年龄和性别对双峰T波检出率的影响。方法回顾性分析明确诊断为先天性心脏病例675例和680例健康者（对照组）的平静心电图,分析双峰T波在先天性心脏病中的检出率和在室间隔缺损（VSD）、房室间隔缺损（AVSD）、房间隔缺损（ASD）和法洛四联症（F4）患者中的检出率。结果①与对照组比较,先天性心脏病中出现双峰T波患者401例（检出率59.4%,p〈0.05）,其中,双峰T波在ASD中检出率42.1%,在VSD中检出率70.6%,AVSD双峰T波出现38例（82.2%）,在F4中出现率42.3%;检出圆顶尖角T波及尖角T波169例（检出率26.0%）;②随着年龄增长,先心病组及正常人群组双峰T波检出率降低;③正常人群组双峰T波检出率男性15岁左右开始逐渐下降,女性20-30岁检出率达高峰。结论双峰T波在先天性心脏病患者中检出率高于正常人;双峰T波受年龄的影响,正常人群还受性别的影响。     

Underlying cardiomyopathy in patients with ST-segment elevation in the right precordial leads.

BACKGROUND: Ventricular fibrillation (VF) and sudden death (SD) may occur in patients with ST-segment elevation in the right precordial leads. The mechanism of such events is unclear, so the aim of the present study was to assess whether there is an underlying morphological or pathological abnormality in these patients. METHODS AND RESULTS: Fourteen consecutive patients (44+/-10 years old, all male) with ST-segment elevation of more than 2 mm in the right precordial leads underwent a cardiac evaluation, including right ventriculography and endomyocardial biopsy. The ST-segment changes after the administration of sodium-channel blockers were also evaluated. Two patients survived documented VF, 11 patients had chest pain or tightness, and another patient had a history of syncope. Only 1 patient had a family history of premature SD. The coronary angiograms were normal in all the patients. VF was induced in 5 patients (36%). Wall motion abnormalities of the right ventricle were detected in 4 patients (29%) and endomyocardial biopsy revealed features of cardiomyopathy in 7 patients (50%). In total, 9 (64%) of 14 patients exhibited wall motion abnormalities and/or pathologic findings. CONCLUSIONS: Underlying cardiomyopathy was present in more than half of the present patients with ST-segment elevation in the right precordial leads.     

The QRS phasic characteristics of right ventricular hypertrophy in precordial leads.

The QRS apparent phase in some electrocardiograms (ECGs) progresses in opposite directions in the two halves of the precordial leads. The genesis of the waveforms leading to such bidirectional phase properties may be given in terms of the particular shapes of the horizontal vector loops. Such phasic properties associate themselves with right ventricular hypertrophy (RVH) of type A and type C although the reverse is not necessarily true. Schematic diagrams are generally used in this article for clarity in illustration, but the method has been tried on some well-documented cases of RVH, reported by Chou and Helm, 3 with promising results.     

Augmentation of QRS wave amplitudes in the precordial leads during narrow QRS tachycardia

INTRODUCTION: QRS morphology during narrow QRS supraventricular tachycardia in patients without ventricular preexcitation generally is considered the same as that seen during sinus rhythm. This study presents a new ECG observation that the QRS amplitude increased significantly in leads V2 through V5 during tachycardia. METHODS AND RESULTS: Using the same ECG machine and the same electrode patches applied to the same electrode positions, 12-lead ECGs during sinus rhythm and narrow QRS tachycardia were analyzed comparatively in 23 patients without ventricular preexcitation. Precordial QRS amplitudes were measured as the vertical distance from the peak of the R to the nadir of the S wave. The amplitudes also were measured during atrial rapid pacing and extrastimulation. Furthermore, ventricular excitation during sinus rhythm and tachycardia was studied using body surface mapping. Body surface distributions of QRS potentials and ventricular activation time (VAT) were displayed as maps. Gross area of QRS (AQRS, equivalent to the QRS amplitude) was compared during sinus rhythm versus tachycardia. During tachycardia, QRS amplitude significantly increased in leads V2 through V5, without any noticeable change in the transitional zone or QRS wave duration. Increase of QRS amplitude also was noted during atrial rapid pacing and extrastimulation. Gross AQRS values during tachycardia significantly increased in the left parasternal area, whereas QRS isopotential and VAT isochronal maps were similar during sinus rhythm and tachycardia, suggesting a minimal role of conduction delay in the increase of QRS amplitude. CONCLUSION: QRS wave amplitude significantly increased in leads V2 through V5 during narrow QRS tachycardia compared with QRS waves in sinus rhythm. Increase of QRS amplitude seemed unlikely due to a conduction delay within the ventricular myocardium.