Clinical and electrocardiographic characteristics of acute pulmonary embolism with ST elevation in the right precordial leads

Background ST-segment elevation(STE) in the right precordial leads is an ECG manifestation of acute pulmonary embolism(APE) and some patients present with concomitant STE in the inferior leads. This clinical entity apparently deserves careful attention. Methods We included 42 APE patients presenting with ≥ 0.1 mV STE in leads V1-V3/V4. Clinical and ECG characteristics in 15 patients with and 27 without STE in the inferior leads were included for comparison. Results Of the 42 patients, 98% were classified as high or intermediate risk patients, 79% showed ECG signs of right ventricular strain(RVS) and 83% showed the maximal amplitude of STE in leads V1-V2. The patients with STE in the inferior leads presented with faster heart rate(131±30 vs. 108±21beats/min, P=0.015), lower systolic blood pressure(107±22 vs. 123±26 mm Hg, P=0.043), higher incidence of elevated troponin(87% vs. 56%, P=0.040) and need to intensify therapy(73% vs. 33%, P=0.013). Conclusions STE in the right precordial leads is an ECG manifestation of intermediate to high risk in APE patients. The ECG characteristics include the maximal amplitude of STE in leads V1-V2 and the RVS pattern. Simultaneous STE in the inferior and right precordial leads is associated with hemodynamic instability and need for intensified therapy.     

QT-interval prolongation in right precordial leads: an additional electrocardiographic hallmark of Brugada syndrome

OBJECTIVES: The aim of this study was to evaluate whether the occurrence of the Brugada Syndrome typical electrocardiogram (ECG) pattern (i.e., right bundle branch block, coved-type ST-segment elevation, and T-wave inversion in the right precordial leads) is characterized by a concomitant lengthening of QT intervals in the right precordial leads. BACKGROUND: It has been suggested that the typical ECG pattern of Brugada syndrome is due to a decreased net inward current during phase 1 of the action potential, which also leads to its prolongation in the right epicardium. METHODS: Thirty-two subjects (19 males) age 37 +/- 15 years with a suspicious baseline ECG, or who were relatives of Brugada syndrome patients, underwent 12-lead ECG before and after the administration of flecainide. RESULTS: The flecainide test was negative in 14 and positive in 18 subjects. After flecainide administration, the positive ECGs were characterized by a greater QT interval corrected for heart rate (QTc) prolongation in the right precordial leads than that in the negative ECGs (78.2 +/- 35.5 ms vs. 22.0 +/- 28.4 ms in V(1) and 107.1 +/- 43.8 ms vs. 26.7 +/- 30.1 ms in V(2); p < 0.01), whereas there was no difference in the QTc prolongation in the left precordial leads (55.2 +/- 25.3 ms vs. 35.1 +/- 28.1 ms in V(5) and 53.1 +/- 32.8 ms vs. 27.3 +/- 22.4 ms in V(6); p = NS). CONCLUSIONS: In accordance with the electrophysiological background, the typical ECG pattern of Brugada syndrome is also characterized by a considerable prolongation of the QT interval in 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.     

Vertical displacement of the precordial leads alters electrocardiographic morphology

BACKGROUND: The present study was undertaken to assess whether the vertical displacement of electrodes affects the waveforms of precordial leads. METHODS AND RESULTS: Two hundred forty healthy, adult volunteers had a standard 12-lead electrocardiogram, a 12-lead electrocardiogram with the precordial leads displaced 2 cm cranially, and another with the precordial leads displaced 2 cm caudally from the standard positions. All the three sets of electrocardiograms were visually compared, and changes noted. One hundred twenty male and 120 female volunteers, 20-68 years of age, were analyzed. Fifty-four males (45.0%) and 2 females (1.7%) showed no difference between the 3 sets of electrocardiograms, while 66 males (55.0%) and 118 females (98.3%) had some changes. R wave amplitude changes were noted in 63 male (52.5%) and 111 female (92.5%) volunteers; S wave amplitude changes were seen in 59 males (49.2%) and 99 females (82.5%,); T wave changes in 5 males (4.2%) and 3 females (2.5%); ST segment changes in 1 male (0.8%) and none of the females; and ORS morphologic changes in 1 male (0.8%) and 12 females (10.0%). CONCLUSIONS: Precordial electrocardiographic waveform changes were seen with the vertical displacement of the precordial leads. This will have implications on the interpretation of serial electrocardiograms. Healthcare providers should take into consideration this deviation when interpreting serial ECGs.     

New precordial bipolar electrocardiographic leads for detecting left ventricular hypertrophy

Background

Novel small and wearable electrocardiogram (ECG) devices offer new means of recording cardiac activity in different applications. Our objective was to evaluate the performance of closely separated (6 cm) bipolar leads in differentiating subjects with left ventricular hypertrophy (LVH) from healthy subjects.

Methods

The material contained body surface ECG of 236 healthy and 116 LVH subjects. A total of 36 vertical, 30 horizontal, and 66 diagonal bipolar leads located on the anterior thorax were analyzed. The QRS amplitudes were calculated, and the leads' overall diagnostic performance was assessed by receiver operating characteristic (ROC) analysis.

Results

The best overall diagnostic performances were obtained from 2 areas: one near the precordial electrodes of standard leads V₁ to V₃ and the other on lower anterior thorax. Vertical and diagonal bipolar leads located at lower anterior thorax provided the highest ROC areas (≥0.79). These bipolar leads also provided similar sensitivities than the traditional Sokolow-Lyon method.

Conclusion

The new short distance vertical and diagonal bipolar leads are efficient in discriminating subjects with LVH from healthy subjects based on QRS amplitude.     

An overlooked electrocardiographic sign of acute embolic cor pulmonale: elevation of the ST segment in right precordial leads

Elevation of the ST segment in the right precordial leads may be associated with electrocardiographic signs of acute cor pulmonale. This sign, which we have observed in 77 cases of moderate to severe pulmonary embolism (greater than 1.3 per cent of cases), is a very early but transient sign of usually moderate to severe pulmonary embolism. In the presence of this sign, the diagnosis of pulmonary embolism with acute cor pulmonale should be proposed at the same time as more common aetiologies such as coronary insufficiency and pericardial disease.     

The right precordial leads in congenital heart diseases manifesting right ventricular preponderance

1. (1) The electrocardiographic patterns of right precordial leads in 91 cases of congenital heart disease manifested by right ventricular preponderance were studied.

2. (2) In uncomplicatcd atrial septal defects an incomplete right bundle branch block was always present.

3. (3) The great majority of the systolic overload group presented the classical complexes in V₁ of R, RS, qR, notched R.

4. (4) In the systolic overload group 18 per cent of the cases manifested an rsR' complex with a short-duration initial r wave, which we feel represents hypertrophy of the crista supraventricularis.

5. (5) The duration of the initial r wave in rsR' patterns was used to distinguish between complexes representing incomplete right bundle branch block and those representing hypertrophy of the crista supraventricularis.

6. (6) A hypothesis has been presented to explain the evolution of the rsR' pattern.

     

A simple method for the routine recording of precordial electrocardiographic leads in infants

A new and simple method of recording precordial electrocardiographic leads in infants, using positive pressure electrodes instead of negative pressure (suction) electrodes, is described.     

Massive ST-segment elevation in precordial and inferior leads in right ventricular myocardial infarction

This report describes a case of right ventricular infarction in which massive ST-segment elevation in the precordial and inferior leads was observed. The maximum magnitude of the ST-segment elevation in the precordial leads was 21 mm in lead V2 and that in the inferior leads was 10 mm in lead II. Angiography revealed a reduction of 90% in the diameter of the right coronary artery in its proximal portion and a normal left coronary system. Recent reports have shown that precordial ST-segment elevation may reflect right ventricular infarction. However, no previously reported instance except our case has shown massive ST-segment elevation in both the precordial and inferior leads. In right ventricular infarction, the current of injury is usually simultaneously present in the right ventricular free wall and left ventricular inferior wall, electrically opposed to each other. Thus, the diffuse and massive ST-segment elevation observed in this study seems to be a rare phenomenon.     

The triad secondary R waves, RS-T segment elevation and T waves inversion in right precordial leads: a normal electrocardiographic variant.

A bizarre electrocardiogram characterized, in right precordial leads, by the triad, high secondary R waves, marked RS-T segment elevation and deep T waves inversion, was observed in an otherwise normal individual. Its persistence for forteen years and its absence at lower levels than in routine right precordial leads demonstrate its nonpathological origin. The few similar cases reported in the literature are reviewed and theie mechanism is discussed.