Epicardial isopotential mapping from body surface isopotential mapping in myocardial infarction

It is useful to construct the epicardial isopotential mapping (the Ep Map) from the body surface isopotential mapping (the Body Map) for clinical diagnosis of cardiac disease, even though there are many unsolved problems in using the inverse solution. Yamashita et al. carried out this solution by using the finite element technique. In the present study, the clinical value of that method has been investigated in cases of myocardial infarction. The Ep Maps at 20, 25 and 30 msec. from the beginning of the QRS complex were obtained from the Body Map at the same time by using that method; the infarcted areas on the Ep Map were determined by using Toyama's method which was reported in a previous study. The infarcted area at 30 msec. on the Ep Map was located at the anterior wall along the ventricular septum in anterior infarction and at the posterior wall of the left ventricle in inferoposterior infarction. Patients were independently examined with the scintigram with thallium-201 and the infarcted area was coincident to the location of the abnormal findings of the scintigram. Moreover, the size of the infarcted area on the Ep Map and the size of the abnormal findings of the scintigram were parallel in most cases except one.     

Colored spatial mapping electrocardiography for detecting myocardial infarction

Colored spatial mapping electrocardiography (ECG) was developed for practical use from Frank lead vectorcardiography using a microcomputer system (CERX-CQ3001). Compared to body surface electrocardiography this new device facilitated easy recording and analysis for display on eight-colored spatial mapping electrocardiography at points equivalent to those on a terrestrial globe at intervals of 20 degrees longitude and 10 degrees latitude. In this study, the extent and direction of the Q waves were easily recognized with the aid of a colored display and mapping electrocardiography. To quantitatively evaluate infarct size, the total Q wave area (sigma Aq) was calculated from the mapping electrocardiograms of 12 patients with anteroseptal myocardial infarction, and compared with thallium defect scores obtained by single photon emission CT (SPECT) and the left ventricular ejection fraction (EF). Defect scores were calculated using short-axis images. Sigma Aq was correlated with defect scores and EF (r = 0.83, 0.45, respectively). This new type of colored spatial mapping electrocardiography proved useful for detecting myocardial infarction and for evaluating infarct size.     

Body surface isopotential maps during the first week of life

One hundred body surface isopotential maps for 30 normal infants, ages three hours to seven days, were evaluated. Ventricular activation and recovery were examined. In the early and mid phase of QRS, the maximum moved from the center of the anterior chest to the lower right portion of the anterior chest. In the late phase, the maximum appeared on the back. The niche appeared earlier in normal newborn infants (19.6 +/- 3.9 msec) (mean +/- S.D.) than in normal children (25.7 +/- 4.6 msec) (P less than 0.001). The location of the maximum at the time of peak positive potentials gradually shifted leftward during the first week of life. The 100 T wave maps were classified into three types. During the first day of life, the T wave maps showed type I or II, changing to type II or III a few days after birth. All T wave maps were type III a week after birth. The ratio of type III gradually increased with age. We found that the QRS maps were different from those of normal children and that T wave maps changed within the first week of birth.     

Body surface isopotential maps in old inferior myocardial infarction undetectable by 12 lead electrocardiogram

The purpose of this study is to examine the value of body surface isopotential maps in the diagnosis of old inferior myocardial infarction that can not be diagnosed by 12 lead ECG. Forty-three patients with a Q wave of at least 0.02 sec but less than 0.04 sec in width and also less than 25% of the R wave in depth in lead a VF of the 12 lead ECG were selected for this study. The patients were divided into infarction and noninfarction groups based on their clinical histories and cardiac catheterization data. The infarction group showed characteristic surface maps with a minimum which moved from the left posterior chest to the lower back or from the lower back to the right anterior lower chest in the early phase of QRS. The noninfarction group exhibited a minimum which shifted from the back to the right upper chest or from the left anterior chest to the lower back in the same phase. Thus, both groups were clearly distinguishable from each other by the positional change of the minimum in the early phase of QRS. This study suggested that body surface maps contain diagnostic information concerning the presence or absence of inferior myocardial infarction which is not easily available from the 12 lead ECG.     

Body surface isopotential mapping in Wolff-Parkinson-White syndrome: Noninvasive method to determine the localization of the accessory atrioventricular pathway

The body surface isopotential maps of 22 patients with WPW syndrome were obtained from the 85 unipolar lead ECG's using the on-line minicomputer system newly devised by the author's group.The map patterns were classified into three types—I, II, and III (Type I, eight; Type II, seven; Type III, three; and unclassified, four cases). In Type I, the back surface displayed the negative potential throughout the entire ventricular activation, and at the terminal stage the lower precordial area displayed the positive potential and the upper precordial area, the negative one. Type II was characterized by two longitudinal lines, one staying at its place on the back and the other moving right to left on the precordial area following the process of ventricular activation. In Type III, the right precordial area displayed negative potential in the early stage, and in the terminal stage the upper part of the right side of chest surface displayed positive potential and the lower part, negative potential.It was surmised from these patterns that the pre-excited area was located at the posterior region of the ventricles in Type I, at the right ventricle in Type II, and the right ventricular base near the posterior margin of the ventricular septum in Type III.Type A patients in the conventional ECG classification fell under Type I; Type C patients, under Type III; Type B patients under either Type I or Type II.     

Body surface heart potential mapping in the limited lead system

A goal of the presented study was to analyze and assess the information collected in the assigned electrocardiographic (ECG) arrangement, constituting a "transition" between the two systems of which one is a 87-lead cylindrical system, and the second one is a 30-lead spherical system. The transient 30-electrode arrangement has been selected from the 87-lead ECG network with the arbitrarily assigned electrodes location, which corresponded to the spherical network called "diamentoid". A subject of the visual inspection and analysis were isopotential and isointegral maps created in the three following lead systems: "total", 87-lead cylindrical system; "transient", 30-lead (limited lead) system, and 30-lead spherical system derived from the latter as a result of the diamentoid transformation. The performed comparisons were focused on determining the similarities and differences between the maps gained from the "full" and "limited" lead systems. The maps representing the entire cardiac cycle, constructed on the base of the ECG recordings obtained from the 53 patients, were assessed. The maps, covering the complex QRS divided in the eight portions, were subjected to the detailed analysis. As the result of the comparative analysis of the body surface maps generated in the given three lead systems, it could be concluded that isopotential and isointegral maps from the both 30-lead systems are capable to retain the significant information concerning the features of potentials distribution, as compared with the data provided by the 87-lead system.     

Body surface isopotential maps. Clinical application to the diagnosis of myocardial infarction

This paper is a review of recent work relating body surface isopotential maps to the detection of the site and extent of myocardial infarction in cases which are either indetectable or difficult to diagnose through the use of standard 12 lead ECGs. According to the difference of the site and extent of myocardial infarction, the characteristic maps are obtained. Through the use of body surface isopotential maps, the significant clinical information may be obtained in a number of cases, and we can do better with mapping than without it in the evaluation of patients with myocardial infarction.     

Myocardial infarction size and location: a comparative study of epicardial isopotential mapping, thallium-201 scintigraphy, electrocardiography and vectorcardiography

Based on epicardial isopotential mapping (the Ep Map), which was calculated from body surface isopotential mapping (the Body Map) with Yamashita's method, using the finite element technique, we predicted the location and size of the abnormal depolarized area (the infarcted area) in 19 clinical cases of anterior and 18 cases of inferoposterior infarction. The prediction was done using Toyama's diagnostic method, previously reported. The accuracy of the prediction by the Ep Map was assessed by comparing it with findings from thallium-201 scintigraphy (SCG), electrocardiography (ECG) and vectorcardiography (VCG). In all cases of anterior infarction, the location of the abnormal depolarized areas determined on the Ep Map, which was localized at the anterior wall along the anterior intraventricular septum, agreed with the location of the abnormal findings obtained by SCG, ECG and VCG. For all inferoposterior infarction cases, the abnormal depolarized areas were localized at the posterior wall and the location also coincided with that of the abnormal findings obtained by SCG, ECG and VCG. Furthermore, we ranked and ordered the size of the abnormal depolarized areas, which were predicted by the Ep Map for both anterior and inferoposterior infarction cases. In the cases of anterior infarction, the order of the size of the abnormal depolarized area by the Ep Map was correlated to the size of the abnormal findings by SCG, as well as to the results from Selvester's QRS scoring system in ECG and to the angle of the maximum QRS vector in the horizontal plane in VCG.(ABSTRACT TRUNCATED AT 250 WORDS)     

Detection of experimental right ventricular infarction by isopotential body surface mapping during sinus rhythm and during ectopic ventricular pacing

Electrocardiographic (ECG) effects of experimental, isolated right ventricular infarction were studied in 10 dogs during sinus rhythm as well as during ectopic right and left ventricular pacing. Infarction was produced by injecting latex into the right coronary artery and ECG consequences were examined by body surface isopotential mapping methods using an 84 electrode torso array. During sinus rhythm, subtraction of preinfarction from postinfarction maps demonstrated that right ventricular necrosis produced abnormal negative potentials over the right hemithorax during the early, middle and late portions of the QRS complex. These patterns corresponded to loss of R waves and deepening of preexistent or development of new Q and S waves in waveforms from this region. Patterns during ectopic ventricular stimulation were compared with mean maps derived from 13 control dogs. Both left and right ventricular pacing after right ventricular infarction resulted in a right-sided abnormal minimum, similar in location to that observed during sinus rhythm, throughout the QRS complex. Thus, right ventricular necrosis does produce QRS complex changes over the right torso that are analogous to those produced by left ventricular infarction, and the dominant pattern of an abnormal right-sided minimum was present regardless of the ventricular activation pattern. This latter finding suggests that the region of right ventricular necrosis provided a supplementary path for current to reenter the heart regardless of the current source, so that an overlying electrode would record negative voltage with all activation patterns.     

Body surface ultrasonography-guided bronchofiberscopy]

Transbronchial lung biopsies and cytologic studies under ultrasonographic guidance from the body surface were conducted in 39 patients whose lesions were adjacent to the thoracic wall. In 26 patients, biopsy, curettage, or brushing forceps were visualized in the mass or infiltrative lesion by thoracic echogram. Positive findings were obtained in 23 patients, for a conclusive diagnostic rate of 88.5%. Of the 13 patients in whom forceps could not be visualized by echogram, 10 had positive findings, for a diagnostic rate of 76.9%. For visualization by thoracic echogram, abnormal lung lesions must be in direct contact with the thoracic wall. Occasionally, diagnostic procedures may be impeded by anatomical structures such as shoulder joints or scapula. Despite these disadvantages, the ultrasonography-guided bronchofiberscope is quite useful because it facilitates real-time confirmation of the positioning of the forceps relative to the lesions. It is also useful in cases when the peripheral lesions are too small or vague to be demonstrated by fluoroscopy alone, because the echo probe can be the target of the forceps instead of the missing shadows. The diagnostic rate should be higher when the forceps are visualized in the lesions ultrasonographically.     

Determination of the preexcitation focus in the W-P-W picture by isopotential body-surface mapping

Experiences with the determination of the preexcitation focus in 13 patients with W-P-W syndrome aged 18-62 years are presented. The data of ECG mapping from the chest surface and the abdominal wall were processed by computer. For classification of the maps the criteria elaborated by Yamada et al., da Ambroggi et al., and Benson et al. were used. It was possible to determine on their basis the preexcitation focus in all examined subjects, although a reduced system of ECG leads was employed. Surface ECG mapping makes possible a more precise location of the preexcitation, which is of great clinical importance for the indication of surgical treatment, determination of prognosis and of working ability.