Bertram J. Allenstein

The direct spatial vectorcardiogram in the infant

Abstract 1. 1. The resemblance of the normal neonatal vectorcardiogram to adult right ventricular hypertrophy is confirmed. Since this is a normal finding, the term “physiological right ventricular preponderance” is used. 2. 2. A previously unnoted transition from “physiological right ventricular preponderance” to the normal adult vectorcardiogram is described. This consists of the development of a progressively larger counterclockwise twist in the horizontal plane until only a counterclockwise loop remains. 3. 3. This transition begins at about thirty days in the infant of normal weight and size. After this age, if the infant has maintained a normal weight, the presence of a vectorcardiogram in the right anterior inferior octant with a clockwise horizontal plane loop probably indicates right ventricular hypertrophy. 4. 4. The significance of the figure-of-eight horizontal plane vector loop is discussed.

The spatial vectorcardiogram in myocardial infarction typified by prominent R waves in Leads aVR and V1

Abstract 1. 1. Five patients with myocardial infarction and prominent or tall R waves in Leads aV R and/or V 1 are reported. 2. 2. Vectorcardiographic studies revealed that the spatial vector loop was in the right superior anterior octant in three patients, right superior posterior octant in the fourth patient, and left superior posterior octant in the fifth patient. The horizontal plane vector loop was strikingly displaced to the right in four of the five patients. 3. 3. The development of tall R waves in Leads aV R and V 1 is shown in two patients. 4. 4. Evidence is presented that these prominent R waves occur in either antero- or posterolateral wall myocardial infarction and that the infarct must be large in ratio to the remaining myocardium. 5. 5. The spatial vectorcardiogram clearly explains the reason for the prominent R waves and the concept of cardiac rotation need not be involved.

Clinical studyDiaphragmatic myocardial infarction with peri-infarction block: Studies of the electrocardiogram and vectorcardiogram

Abstract Presented here are the vectorcardiograms and electrocardiograms of 10 normal patients, 12 with diaphragmatic infarction, 15 with diaphragmatic infarction and diaphragmatic peninfarction block, 3 with right bundle branch block, and 4 with diaphragmatic infarction plus right bundle branch block. The characteristics of the electric patterns of diaphragmatic infarction with diaphragmatic peri-infarction block are: 1. (1) Diaphragmatic infarction changed the initial QRS vector, pointing it away from the site of infarction (diaphragm). Orientation was leftward, superiorly and anteriorly. 2. (2) In diaphragmatic peri-infarction block, the terminal QRS vector was altered and directed toward the site of infarction (diaphragm) and oriented to the right, posteriorly, and inferiorly or superiorly. 3. (3) In the electrocardiogram, QRS prolongation greater than 0.10 sec. seldom occurred. However, the vectorcardiogram always showed terminal 0.03 sec. QRS loop slowing. In peri-infarction block, the terminal vector was slowed and in the right, posterior quadrant; in right bundle branch block, terminal depolarization was again slowed but located in the right, anterior quadrant. The depolarization delay in peri-infarction block, seen only by vectorcardiogram, may be due to abnormal repolarization with early repolarization potentials altering and delaying the apparent terminal depolarization vector. How the tracings of peri-infarction block and right bundle branch block differed from the normal and from diaphragmatic infarction without block is illustrated and discussed.

QRS PATTERN IN MITRAL STENOSIS.

Abstract 1. 1. There are three types of electrocardiograms and vectorcardiograms seen with mitral stenosis (with or without mitral insufficiency): (a) the right ventricular type of anterior QRS loop which is the most common; (b) the combined hypertrophy type; and (c) the emphysema type or posterior QRS loop. This latter group has not been emphasized as having diagnostic significance for mitral stenosis. Eight examples of the posterior type are presented here. 2. 2. Pathologic data give a basis for understanding the appearance of opposite electrical manifestations in a single disease state. 3. 3. Although examples of both anterior and posterior types are emphasized in this paper, it is to be expected that mixtures exist. The recognition of the electrical patterns which result from a variety of “blends” is not difficult. 4. 4. In the vectorcardiogram and electrocardiogram it may be possible to differentiate the posterior QRS loop of chronic lung disease from that of mitral stenosis.

The normal direct spatial vectorcardiogram

Abstract 1. 1. One hundred presumably normal patients were studied by direct spatial vectorcardiographic methods using the modified cube technique. 2. 2. The tracings were described in terms of relatively constant findings, as well as with commentary on unusual characteristics. 3. 3. No correlation between direction of inscription of the frontal loop and the axis deviation or ECG-determined electrical position was noted, except in patients over 80 years of age. 4. 4. By dividing the cases into decades by increasing ages, a trend in vector orientation from the anterior inferior toward the posterior superior octant was observed. In view of this transition with age, it is suggested that in the interpretation of vectorcardiograms the age of the patient be considered. 5. 5. More specific criteria for the limitations of normal is indicated but necessitates collection of large series of normal cases and eventual pathologic correlation.

PULMONARY ARTERY STENOSIS; FOLLOW-UP STUDY.

first detected in this 14-month old Caucasian male when he was 5 months old. At birth the child weighed 5 pounds, 6 ounces. The parents complained of his poor health and frequent feedings, retarded physical development, shortness of breath on slight exertion, and poor vision. Physical examination revealed an underdeveloped white child, not cyanotic, 29 in. tall and weighing 19 lb. A central cataract of the left eye was very apparent. Each foot exhibited mild valgus deformity and crowding of the toes. Blood pressure was 100/54; lungs were clear; the heart was not enlarged by palpation and percussion. There were no thrills. The pulmonary second sound was accentuated. A grade III, holo-systolic murmur was heard loudest at the 2nd left intercostal space, not radiating into the neck.

Variations in direct spatial vectorcardiograms resulting from altered placement of electrodes in the cube system

Abstract 1. 1. Eight patients with normal cardiovascular systems were examined by direct spatial vectorcardiography. In all cases normal vectors were noted when the usual electrode placement was used. 2. 2. By varying the location of the shoulder electrodes, the distances between the right chest electrodes, and the depth of respiration, no significant changes were noted. 3. 3. In three of eight cases, upon placing the chest electrodes at T 12 instead of L 2, vector loops suggesting early left ventricular hypertrophy were produced as a result of change in spatial orientation of the loops. In one of these cases a configuration suggesting anterior infarction was noted. 4. 4. The need for proper placement of chest electrodes with respect to vertebral level is emphasized.