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PubMed2003

Pseudonormalized Doppler total ejection isovolume (Tei) index in patients with right ventricular acute myocardial infarction.

The Doppler total ejection isovolume (Tei) index is useful for estimating global cardiac function. However, the relation between the right ventricular (RV) Tei index and RV infarction has not been investigated. The relation between the RV Tei index and severity of RV infarction was evaluated in 25 patients with inferior wall acute myocardial infarction (13 with and 12 without RV infarction). RV infarction was diagnosed when right atrial pressure was > or = 10 mm Hg or when right atrial pressure/pulmonary capillary wedge pressure was >0.8 by catheterization. The RV Tei index was significantly increased in patients with RV infarction compared with those without (0.53 +/- 0.15 vs 0.38 +/- 0.14, p <0.05). The RV Tei index in patients with severe RV infarction (right atrial pressure > or = 15 mm Hg) was significantly smaller compared with those with mild/moderate RV infarction (right atrial pressure <15 mm Hg) and showed no significant difference in patients with myocardial infarction but without RV infarction (0.44 +/- 0.09 vs 0.61 +/- 0.16 vs 0.38 +/- 0.14, severe RV infarction vs mild/moderate RV infarction vs no RV infarction, p <0.01). The RV Tei index is generally increased in patients with RV infarction; however, severe RV infarction can be manifested with limited or no increase in the Tei index (pseudonormalization).

Adult↗

PubMed1985

Biaxial mechanical properties of the pericardium in normal and volume overload dogs.

The two-dimensional mechanical properties of the pericardium from dogs with a normal or chronically enlarged heart were studied in vitro. A 3.0-cm-square piece of the pericardium overlying the right and/or left ventricle was excised. An approximately 1.0-cm-square target was marked at the center, and its dimension was measured electrooptically. When immersed in physiological saline at 37 degrees C, the specimen was stretched and unloaded sinusoidally in one direction while force in the transverse direction was held constant. The tension-stretch relationship was highly reproducible and was insensitive to strain rate in the range of 0.002-0.1 Hz. Hysteresis was present. The pericardium was mostly anisotropic; however, the direction of maximal compliance varied among dogs. The elastic properties of the pericardium overlying the left and right ventricles were the same in most cases. Substantial stress relaxation was observed; in contrast, insignificant creep developed over 30 min. In five dogs with chronic cardiac dilatation due to an infrarenal aortocaval shunt, the tension-stretch curves were shifted significantly to the right (i.e., greater deformation at the same tension level). However, the pericardial viscoelastic properties and thickness were unchanged. In other words, chronic cardiac dilatation resulted in a more compliant pericardium.

Animals↗

PubMed2026

Physical reconfiguration of limb electrodes for Precordial Bipolar Lead acquisition: Morphological validation against digital subtraction.

BACKGROUND: The V2 - V1 Precordial Bipolar Lead (PBL) selectively evaluates the right-to-left retrosternal axis and has shown diagnostic value beyond the standard 12‑lead electrocardiogram. However, its use has been limited by the need for raw electrocardiographic data and post-processing software. This study evaluated whether a simple physical reconfiguration of limb electrodes could reproduce the digitally derived V2 - V1 morphology with sufficient accuracy for clinical application. METHODS: Thirty-seven subjects underwent two sequential 10-s 12‑lead recordings using a Cardiovit FT-1 electrocardiograph sampled at 1000 Hz. In the standard recording, the digital PBL was calculated as V2 - V1. In the second recording, the right-arm and left-arm electrodes were repositioned to the V1 and V2 sites so that Lead I directly recorded the retrosternal dipole. Signals were filtered, synchronized, and analyzed using median beats. Morphological agreement was assessed with Pearson correlation on Z-normalized signals, while absolute agreement was evaluated using Lin's concordance correlation coefficient (CCC), intraclass correlation coefficient (ICC (Lewis, 1931; Nehb, 1938 [1,2])), root mean square error (RMSE), and Bland-Altman analysis. RESULTS: Mean Pearson correlation between digital and physical PBL was 0.955 (SD 0.043), with segment-specific correlations of 0.953 (SD 0.054) for QRS and 0.967 (SD 0.052) for ST-T. Lin's CCC and ICC(2,1) were both 0.871 (SD 0.110), and RMSE was 0.091 (SD 0.049) mV. Bland-Altman analysis showed minimal bias (-0.008 mV). CONCLUSIONS: Physical acquisition of the V2 - V1 PBL achieved high agreement with the digitally derived signal, supporting a simplified analog method for broader clinical implementation.

Humans↗

PubMed2006

Atrial and ventricular echocardiographic correlates of the extent of pulmonary embolism in the elderly.

BACKGROUND: Acute pulmonary thromboembolism (PTE) can be associated with right ventricular (RV) dysfunction. The relative importance of individual echocardiographic parameters, including those suggesting interdependence between right and left heart chambers, in predicting thromboembolic burden in elderly patients with acute PTE is unknown. METHODS: We retrospectively studied the transthoracic echocardiograms of 63 elderly patients (age 71 +/- 16 years) with acute PTE, and assessed which individual echocardiographic parameters identified more than 30% pulmonary artery obstruction on the basis of quantitative ventilation/perfusion pulmonary scintigraphy. RESULTS: RV hypokinesis (visual grade 0-3, P = .02), and the quantitative parameters RV end-systolic area (P = .005) and RV ejection area (P = .01) were associated with more extensive pulmonary artery obstruction. Although right atrial end-systolic area and RV end-diastolic area did not correlate with extent of PTE, the ratio of RV:left ventricular end-diastolic area (P = .003), and ratio of right:left atrial end-systolic area (P = .004), were strongly associated with the extent of pulmonary artery obstruction. These transthoracic echocardiographic parameters were independent of clinical variables such as prior chronic lung disease, congestive cardiac failure, or prior PTE. CONCLUSION: RV systolic dysfunction, RV end-systolic dilatation, right:left atrial end-systolic area ratio, and RV:left ventricular end-diastolic area ratio correlate with extent of PTE in the elderly.

Aged↗

PubMed2001

Interpretive intra- and interobserver reproducibility of rest/stress 99Tcm-sestamibi myocardial perfusion SPECT in a consecutive group of male patients with stable angina pectoris before and after percutaneous transluminal angioplasty.

BACKGROUND: Observer variability of 99Tcm-sestamibi myocardial perfusion imaging (MPI) has rarely been investigated. The aim of our study was to evaluate the interpretive reproducibility with this technique. PATIENTS: We report on 108 consecutive male patients with stable angina pectoris, investigated before and after percutaneous transluminal angioplasty (PTCA). METHODS: A 2-day rest/stress 99Tcm-sestamibi gated single photon emission computed tomography (SPECT) protocol was used. MPI was interpreted by two independent observers without knowledge of clinical data, using a 20-segment scoring model. RESULTS: Intra- and interobserver agreement was found to be good to excellent (kappa = 0.71-0.85) with regard to the overall diagnosis as well as the individual vessel diagnosis (kappa = 0.60-0.87). However, agreement was higher for left anterior descending coronary artery (LAD) and left circumflex coronary artery (LCX) vascular territories than for the right coronary artery (RCA) territory. Moderate to good intraobserver agreement (kappa = 00.54-0.68) and slightly lower interobserver agreement (kappa = 0.52-0.56) was found for segmental score interpretation. When comparing the interpretive reproducibility before and after PTCA intra- and interobserver agreement was better after PTCA, probably reflecting the increase in normal scans after revascularization. CONCLUSIONS: In a group of consecutive male patients with stable angina pectoris interpretive reproducibility (overall and individual vessel diagnosis) was good to excellent. However, segmental scoring reproducibility was moderate to good.

Adult↗

PubMed2005

Tissue Doppler imaging and brain natriuretic peptide levels in adults with repaired tetralogy of Fallot.

BACKGROUND: Accurate estimation of right ventricular (RV) function in patients with repaired tetralogy of Fallot (RTOF) is difficult, partly due to the presence of tricuspid regurgitation and pulmonary regurgitation and/or stenosis. The aim of the present study was to evaluate RV systolic and diastolic function of adult asymptomatic patients with RTOF by means of tissue Doppler imaging (TDI) and brain natriuretic peptide (BNP) values. METHODS: 25 adult patients with RTOF and 25 healthy controls were studied. The following echocardiographic measurements were obtained: RV diameter/left ventricular (LV) diameter (RVD/LVD) and systolic (Sa) and diastolic (Ea, Aa) velocities at the RV free wall tricuspid annulus site. Serum BNP levels were measured as well. RESULTS: Patients with RTOF demonstrated reduced TDI velocities: Sa, 8.16 +/- 1.15 versus 16.43 +/- 1.15 cm/sec (P < .001); Ea, 10.00 +/- 2.18 versus 18.99 +/- 1.00 cm/sec (P < .001); Aa, 5.64 +/- 1.77 vs. 13.69 +/- 0.86 cm/sec (P < .001). Patients with RTOF also had higher BNP levels than controls (85.0 +/- 87.0 vs 5.36 +/- 1.0 pg/mL; P < .001). The increased BNP levels in RTOF patients correlated with the RVD/LVD ratio (r = .521; P < .01). CONCLUSIONS: Our results indicate that although our cohort of patients was asymptomatic, using TDI and BNP allowed us to easily discriminate them from the healthy controls. The ability of TDI to assess ventricular function even in the presence of valvular lesions, as in RTOF patients, makes it a valuable tool in the investigation and follow-up of these patients.

Adolescent↗

PubMed2006

Right ventricular function in patients with acute pulmonary embolism: analysis with electrocardiography-synchronized multi-detector row CT.

PURPOSE: To prospectively assess electrocardiography (ECG)-synchronized multi-detector row computed tomography (CT) for the evaluation of right ventricular (RV) function in patients suspected of having pulmonary embolism (PE). MATERIALS AND METHODS: All patients gave informed consent after the study details, including radiation exposure, were explained; institutional ethical committee approval was obtained. Nonsynchronized multi-detector row CT of the chest was performed in 66 consecutive patients (29 men, 37 women; mean age, 58 years+/-15 [standard deviation]) who were suspected of having PE. ECG-synchronized cardiac multi-detector row CT was performed to assess cardiac function. Dimension ratios for the RV and left ventricle (LV) were measured on nonsynchronized transverse and angulated four-chamber views. Furthermore, the RV end-diastolic and end-systolic volumes were measured on ECG-synchronized multi-detector row CT scans. An independent samples t test was performed to compare the mean value of different groups. An analysis of variance post hoc test was performed to investigate whether the values of the variables varied between groups. RESULTS: PE was detected in 29 of 66 patients. The location of PE was categorized as central (n=17) or peripheral (n=12). The RV/LV dimension ratio was larger on the four-chamber view (P=.002), and RV end-systolic volume was larger (P=.01) and ejection fraction was lower (P=.01) in patients with PE. The RV end-systolic volumes and RV/LV volume ratios, as assessed by using ECG-synchronized multi-detector row CT, showed significant differences (P<.005) between patients with central PE and those with peripheral PE. However, the RV/LV dimensions on nonsynchronized images revealed no significant differences. CONCLUSION: Retrospective ECG-synchronized multi-detector row CT facilitates detection of RV dysfunction, depending on pulmonary embolus location.

Acute Disease↗

PubMed1983

Evaluation of left ventricular contractile pattern by intravenous digital subtraction ventriculography: comparison with cineangiography and assessment of interobserver variability.

The accuracy and reproducibility of measurements of left ventricular (LV) end-diastolic volume (EDV), end-systolic volume (ESV), ejection fraction (EF) and regional wall motion obtained by digital subtraction ventriculography (DSV) were compared with values of direct cineangiography in 40 patients, 21 of whom were ambulatory. DSV was performed with a 1-second, 30-ml contrast injection, which yielded real-time fluoroimages composed of 512 X 512 pixels at 30 frames/s. Single-plane right anterior oblique LV volumes were calculated by area-length methods for both DSV and cineangiography. Wall motion was assessed as percent area shortening for 12 equal myocardial segments, with results classified as abnormal if greater than 2 standard deviations below the mean of 20 normal values. DSV exhibited close correlation with angiography for EDV (r = 0.88), ESV (r = 0.92) and EF (r = 0.93). Intravenous DSV and direct cineangiography were concordant in classification of LV contractile pattern in 436 of 480 (91%) myocardial segments. Measurements of DSV obtained by 2 observers showed close correlations for EDV (r = 0.88), ESV (r = 0.95) and EF (r = 0.94), and wall motion classification was in agreement in 434 of 480 (90%) LV segments. Artifacts induced by respiratory motion, persistence of contrast in the right ventricle or left atrium, or low cardiac output may have contributed to the discrepancies observed. These data indicate that DSV is accurate in assessing LV volume and EF, correlates well with cineangiography and exhibits good interobserver reproducibility.

Analog-Digital Conversion↗

PubMed1996

Atrial flutter after lateral tunnel construction in the modified Fontan operation: a canine model.

Intraatrial reentrant tachycardia, or atrial flutter, is a common postoperative problem after Fontan repair, which involves an atriopulmonary connection. A modification of Fontan repair, total cavopulmonary connection, minimizes the portion of the right atrium exposed to stretch and hypertension; however, atrial flutter continues to occur after this procedure. We postulated that the intraatrial lateral tunnel suture line of total cavopulmonary connection, in the absence of physiologic alterations such as atrial hypertension or stretch, provides the necessary electrophysiologic substrate for atrial flutter. The purpose of this study was to produce a canine model of total cavopulmonary connection (1) to establish that the intraatrial suture line alone is sufficient to permit sustained atrial flutter and (2) to characterize the pathways of resulting reentrant arrhythmias. After induction of general anesthesia, 25 to 30 kg dogs (n = 17) underwent median sternotomy, cradling of the pericardium, and placement of a pacing electrode on the right atrial appendage. Normothermic cardiopulmonary bypass was initiated. The total cavopulmonary connection suture line was placed through a standard right atriotomy,simulating construcion of the lateral tunnel. After closure of the atriotomy, 253 point unipolar atrial endocardial form-fitting electrodes were placed through bilateral ventriculotomies. By means of atrial burst pacing and programmed extrastimulation, induction of atrial flutter was attempted. If atrial flutter could not be induced, isoproterenol was infused and the stimulation protocol was repeated. After induction of atrial flutter, mapping of the activation sequence was performed. Before suture line placement, no dog had inducible atrial flutter. After placement of the suture line, sustained atrial flutter was reproducibly induced in every dog, although isoproterenol was required for this in three (17.6%). The mean flutter cycle length was 177 +/- 30 msec. In each case, the atrial flutter circuit was limited to the right atrium, with the left atrium being passively activated. The atrial flutter circuit was dependent on a corridor of myocardium that resulted from conduction block on the free wall, created by the lateral margin of the total cavopulmonary connection. In no case was the atriotomy integral to the atrial flutter circuit. This study establishes that the total cavopulmonary connection baffle suture line alone, without alteration in circulatory physiology, creates a sufficient anatomic substrate for atrial flutter in a short-term canine model. Delineation of the anatomic boundaries of the reentrant circuit raises the possibility of targeting areas within the circuit that could be modified, potentially reducing the incidence of postoperative atrial flutter after total cavopulmonary connection.

Animals↗

PubMed2006

The 3-dimensional construction of the average 11-year-old child face: a clinical evaluation and application.

PURPOSE: This article describes construction of the average face and its application in the clinical environment. SUBJECTS AND METHODS: A total of 72 children, mean age 11.8 years, were selected for the study. Laser-scanned images of the subjects were obtained under a reproducible and controlled environment with 2 Minolta Vivid 900 (Minolta, Osaka, Japan) optical laser-scanning devices assembled as a stereo pair. A set of left and right scanned images was taken for each subject and each scan took an average of 2.5 seconds. These scanned images were processed and merged to form a composite 3-dimensional soft tissue reproduction of the subjects using commercially-available reverse modeling software. The differences in facial morphology were measured using shell deviation color maps. The average face was used to compare differences between male and female groups and 3 subjects with craniofacial anomalies. RESULTS: The difference between the average male and female face was 0.460 +/- 0.353 mm. The areas of greatest deviation were at the zygomatic area and lower jaw line, with the males being more prominent. The results of the surface deviation between the subjects with craniofacial anomalies were significant. CONCLUSIONS: The construction of the average face provides an interesting perspective into measuring changes in groups of patients and also acts as a useful template for the comparison of craniofacial anomalies.

Cephalometry↗

PubMed2000

Reproducibility of measurements with the nerve fiber analyzer (NfA/GDx).

PURPOSE: To determine the reproducibility of measurements with the Nerve Fiber Analyzer, a scanning laser polarimeter designed for quantifying glaucoma in healthy patients and patients with glaucoma. The authors also assessed the variance of measurements between instruments. METHODS: Measurements were made with the third generation Nerve Fiber Analyzer, the GDx. The study consisted of three parts. In the first part, the authors measured the right eyes of 10 healthy volunteers on 5 consecutive days. In the second part, 45 patients with glaucoma underwent Nerve Fiber Analyzer measurements of one randomly selected eye on two separate days in a 5-week period. For all 14 available parameters, reproducibility of measurements was expressed in terms of 95% limits of agreement and as the intraclass correlation coefficient. The Nerve Fiber Analyzer software has an option of creating a mean image from a selection of single images; for both parts of the study, the reproducibility of measurements was calculated for a "single image," and a "mean-of-three" image. In the third part of the study, 17 volunteers underwent repeated Nerve Fiber Analyzer measurement sessions on each of three different instruments. Using multivariate analysis of variance, the authors determined the variance of measurements between instruments. RESULTS: The reproducibility of measurements varied considerably across parameters. Limits of agreement in mean images for superior maximum and inferior maximum were 7.2 microm and 7.7 microm, respectively in the healthy volunteers, and 8.7 microm and 7.9 microm, respectively in the patients with glaucoma. For healthy patients, the intraclass correlation coefficient was greater than 90% in 10 of 14 parameters. In patients with glaucoma, the intraclass correlation coefficient was greater than 90% in 13 of 14 parameters. Some parameters reproduced better in a mean than in a single image; these differences, however, were small and generally not statistically significant. The between-instruments component also varied across parameters and was highest in ratio-based parameters. CONCLUSIONS: The reproducibility of measurements varied across parameters. In general, the reproducibility of measurements with the Nerve Fiber Analyzer was high. The reproducibility of measurements was similar between healthy patients and patients with glaucoma. Any measured change in nerve fiber layer thickness would be statistically significant if it exceeded approximately 7 or 8 microm in the superior maximum or inferior maximum parameter in healthy patients. Reproducibility of measurements hardly differed between single images and mean images. The reproducibility of measurements among the three instruments we used was highest for straight parameters.

Adult↗

PubMed1989

[Problems of mandibular position diagnosis using paraocclusal mechanicpneumatic axiography].

Based on mechanical axiographic examinations of 117 test persons with normal masticatory functions, the reproducibility of the recordings was assessed at 0.2 mm +/- 0.14 mm with maximum deviations of about 0.8 mm. The reproducibility of the protrusion tracings was 7 degrees +/- 7 degrees at 1 mm of protrusion (maximum: 37 degrees) and 2 degrees +/- 2 degrees at 5 mm of protrusion (maximum: 11 degrees). The diagnostic assessment of the positions of the mandible is complicated by the fact that asymmetrical deviations on the right and left may result in errors in the interpretation of distances and directions of deviation.

Dental Articulators↗

PubMed1978

Echocardiographic spectrum of tricuspid atresia.

Standard M-mode and contrast echocardiographic features of 35 patients with tricuspid atresia are reported. These features included a single posteriorly located atrioventricular valve with large excursion, often demonstrating the pattern of systolic prolapse, mitral semilunar valve continuity, and small right ventricular chamber. Left ventricular dimension and left ventricular posterior wall thickness were usually increased. Ventricular septal and posterior wall excursion and percent thickening of the left ventricular posterior wall were in the normal range in most cases. However, fractional shortening of the left ventricular minor diameter was below normal in most patients (26/29, 90%) regardless of the age at presentation. A characteristic and reproducible flow pattern of contrast medium was also observed. After systemic venous injection of indocyanine green, the resultant echoes initially appeared in the left atrium and subsequently, via the mitral valve funnel, appeared in the left ventricular cavity. If a small right ventricular chamber could be recorded, this chamber filled with subsequent systole except in patients with intact ventricular septum. With the use of these M-mode echographic features, along with contrast studies, diagnosis of tricuspid atresia can confidently be established at the bedside and can readily be distinguished from other cyanotic congenital defects.

Adolescent↗

PubMed1979

Hemiparkinsonism. A human model for studying dopaminergic supersensitivity.

The observation of a patient suffering from a parkinsonian syndrome, almost entirely expressed on the right side, and "on-off" attacks with rotatory movement of the trunk, led us to consider that the rotational model of animals may be reproduced in man. The symptoms presented by our patient may reflect a predominant degeneration in the nigrostriatal pathway of the left side. We suggest that his torsion behavior is due to hypersensitivity phenomenon of the dopaminergic receptors on this side.

Animals↗

PubMed1986

Effect of increased current, multiple pacing sites and number of extrastimuli on induction of ventricular tachycardia.

Reproduction of spontaneously occurring ventricular tachycardia (VT) and induction of previously undocumented VT were studied prospectively in 98 patients: 48 with documented sustained VT or ventricular fibrillation, 25 with nonsustained or exercise-induced VT, and 25 with no documented VT. Patients received 1 to 4 ventricular extrastimuli and ventricular burst pacing at 2 right ventricular (RV) sites, first at twice late diastolic threshold, and then at 10 mA using a prospective, tandem study design. Spontaneously occurring VT was reproduced in 37 of 48 patients (77%) at twice late diastolic threshold and in 1 other patient (2%) at 10 mA. VT was reproduced at both RV sites in 17 of 48 patients (35%) and at 1 site in 20 of 48 patients (42%) at twice late diastolic threshold. A previously undocumented VT was induced in 7 of 25 patients (28%) with no documented VT at twice diastolic threshold and 14 of 25 patients (56%) at 10 mA. A previously undocumented VT was induced in 33 of 73 patients (45%) with a history of sustained or nonsustained VT at twice late diastolic threshold and in 47 of 73 patients (64%) at 10 mA. In patients with documented sustained VT, the use of up to 4 ventricular extrastimuli at multiple RV sites increases the sensitivity of the test. In patients without documented VT, the induction of previously undocumented VT with more than 3 ventricular extrastimuli limits the specificity of the test. Increased current provides only a slight advantage over 4 ventricular extrastimuli at twice late diastolic threshold in terms of reproduction of spontaneously occurring VT, but leads to a marked increase in induction of previously undocumented VT.

Aged↗

PubMed2000

Volumetric measurements of right cerebral hemisphere infarction: use of a semiautomatic MRI segmentation technique.

The applications of a new segmentation software, Anatomatic, in the evaluation of volumetric measurements of brain infarctions and the new Medimag 3D software in the evaluation of 3D image representation of infarctions are described. These programs are applied to magnetic resonance imaging. The aim of this study is to evaluate the use of these software packages in making accurate volumetric measurements in 40 patients with right cerebral infarctions, in determining the correlations between the quantitated lesions and neurological/neuropsychological dysfunctions and in creating realistic 3D views of the infarctions. Using Anatomatic, reproducible infarction volumes were achieved with ease and within a reasonably fast time. Medimag helped achieve realistic 3D representations of the infarctions. When compared, the semiautomatic segmentation proved to be much faster and yielded higher infarction volumes than the manual segmentation technique. Significantly positive correlations between the infarction volumes and neurological dysfunctions and neuropsychological deficit (neglect) helped to explain the effect of volumes on the clinical status of the patients.

Adult↗

PubMed1987

Inducible polymorphic ventricular tachycardia and ventricular fibrillation in a subgroup of patients with hypertrophic cardiomyopathy at high risk for sudden death.

This investigation was undertaken to elucidate the underlying electrophysiologic substrate in hypertrophic cardiomyopathy and to identify possible predictors of sudden death in this patient population. Programmed stimulation was performed in 18 patients aged 14 to 64 years (mean 36) believed to be at high risk for sudden death on the basis of prior cardiac arrest or syncope, nonsustained ventricular tachycardia on Holter ambulatory electrocardiographic (ECG) monitoring or a family history of frequent sudden death. Polymorphic ventricular tachycardia that deteriorated to ventricular fibrillation was reproducibly induced in 8 (44%) of the 18 patients (Group A). This rhythm was induced in all three patients with a history of cardiac arrest. No sustained monomorphic ventricular tachycardia was induced. Group B comprised the 10 patients in whom a sustained arrhythmia could not be reproducibly initiated. The electrophysiologic substrate was distinctly different in patients with, than in those without, inducible sustained arrhythmia. The refractory period was shorter at the right ventricular outflow tract (232 +/- 22 ms) compared with the apex (264 +/- 12 ms) in Group A (p less than 0.005) whereas there was no difference in Group B (271 +/- 25 ms versus 271 +/- 13 ms). The local ventricular electrogram of most patients in both groups was prolonged and markedly multiphasic. However, 5 of the 8 Group A patients exhibited a double electrogram (V-V') with premature stimulation compared with 1 of the 10 patients in Group B (p less than 0.02). A positive R wave in lead aVR of the scalar ECG and poor R wave progression in the precordial leads were more common in Group A than in Group B (p less than 0.001 and p less than 0.001, respectively). The reason for the distinctly different electrophysiologic substrate and the high prevalence of inducible polymorphic arrhythmia is unclear. It may relate to the underlying myocardial architecture in these patients, characterized by myocardial cellular disarray and fibrosis.

Adolescent↗

PubMed2001

Vasospastic angina accompanied by Brugada-type electrocardiographic abnormalities.

Brugada Syndrome and Vasospastic Angina. We present two patients with vasospastic angina and Brugada-type ECG abnormalities. The first patient complained of chest pain, and transient ST segment elevation was confirmed on ECG. Coronary angiogram showed no organic stenosis. The second patient had syncopal episodes following anginal chest pain, and the same symptoms were reproduced by intracoronary acetylcholine injection that induced vasospasm. In both patients, ECG at rest showed ST segment elevation in leads V1 and V2 and a right bundle branch block pattern that were accentuated by a Class I antiarrhythmic drug. Ventricular fibrillation also was induced by programmed electrical stimulation. Susceptibility to ventricular fibrillation can be modulated by the interaction of coronary vasospasm with Brugada syndrome or vice versa; therefore, it is important to study the clinical implications of the coexistence of the two diseases in such patients.

Aged↗