George R. Herrmann

A clinical study of complete heart block.

Abstract Complete heart block meeting our criteria is uncommon. Arteriosclerotic heart disease was the chief etiologic factor in 90 out of 49,000 patients on whom electrocardiographic studies were made. Overdigitalization was the most frequent toxic cause. The QRS configuration or duration is considered an unreliable index of the position of the pacemaker, since bundle branch block frequently may coexist with complete heart block. Isuprel (isopropyl norepinephrine) was found to be the most useful drug in our series, regardless of the underlying mechanism producing attacks. In only three of our patients was ventricular fibrillation considered the mechanism producing symptoms. The prognosis depends upon the stability of the idioventricular pacemaker, the presence of symptoms, and the underlying mechanism producing attacks. With some exceptions, however, the prognosis of symptomatic complete heart block is generally poor.

Paroxysmal pseudoventricular tachycardia and pseudoventricular fibrillation in patients with accelerated A-V conduction

Abstract Patients with accelerated atrioventricular conduction are peculiarly prone to paroxysmal atrial tachycardia and atrial fibrillation, which with the conduction anomaly result in very rapid arrhythmias, producing bizarre electrocardiograms. The pseudo bundle branch block causes the development of pseudoventricular complexes and the accelerated atrioventricular conduction gives rise to high ventricular rates that are alarming. These are usually more rapid than the simulated serious ventricular mechanism disorders. The importance of taking the seemingly good general status of the patient into consideration in electrocardiographic interpretation is emphasized. The diagnostic criteria have been set forth with emphasis on the presence of a P wave on every complex in the tachycardia and short runs of definite supraventricular fibrillation with narrow QRS in between the bizarre pseudoventricular runs of complexes. Some of the cases of a paroxysmal ventricular tachycardia and some of the cases of paroxysmal ventricular fibrillation with recovery reported in the literature are probably of this pseudoventricular disorder. The relatively excellent prognosis of the pseudo type is emphasized. However, it must be remembered that, in a rare case, the patient has died suddenly in a paroxysm of tachycardia. The relatively prompt and satisfactory response to procaine amide intravenously has been demonstrated. Some patients seem to be somewhat refractory to quinidine during a paroxysm and digitalization does not effectively slow the ventricular rate in this type of atrial fibrillation and accelerated conduction. The probable pathophysiology of these pseudoventricular paroxysms, tachycardia, or fibrillation have been discussed. The conspicuously high ventricular rates are the result of the accelerated A-V transmission. The clinical axiom follows that the presence of ventricular paroxysmal disorders, regular or irregular, with rates above 240 is presumptive evidence of the presence of accelerated A-V conduction as the fundamental cardiac mechanism disorder in the patient.

A study of cardiac vectors in the frontal plane.

Abstract 1. 1. The Einthoven triangle has been set forth in the circular form. The circular form correlates easily the polarities written in the six limb leads and the corresponding heart-vector direction in the RLF plane. 2. 2. The average QRS vector was directed toward +45 degrees in normal electrocardiograms, toward +120 degrees in right ventricular hypertrophy, and toward +15 degrees in left ventricular hypertrophy. The average QRS′ vector was directed toward +30 degrees in both complete right bundle branch block and left bundle branch block. The average QRS″ vector was directed toward −165 degrees in complete right bundle branch block, and toward −30 degrees in complete left bundle branch block. 3. 3. In normal electrocardiograms the angle formed by the QRS vector and T vector did not exceed 45 degrees. In right ventricular hypertrophy and left ventricular hypertrophy this angle could range between 0 degree and 180 degrees. In complete right bundle branch block the angle formed by the QRS′ vector and QRS″ vector usually exceeded 90 degrees; the average angle was 150 degrees. In complete left bundle branch block the angle formed by the QRS′ vector and QRS″ vector usually did not exceed 90 degrees; the average angle was 45 degrees. 4. 4. The incidence of complete right bundle branch block was 2 per cent, of which 95 per cent were of the Wilson type. The incidence of complete left bundle branch block was 1 per cent. 5. 5. The T vector could not be determined in 4 per cent of right ventricular hypertrophy and in 11 per cent of left ventricular hypertrophy. 6. 6. In the RLF plane the general direction of activation of a single normal ventricle, either right or left, was nearly the same as that of the normal QRS vector. The route of activation of a blocked ventricle, either right or left, was abnormally altered: toward the right in complete right bundle branch block, and toward the left in complete left bundle branch block. 7. 7. The circular form was found to be advantageous in clinical routine electrocardiographic analysis.

Paroxysmal supraventricular tachycardias complicating organic heart disease

Abstract 1. 1. An analysis is presented of 175 consecutive patients with supraventricular paroxysmal tachycardia seen in a teaching hospital practice over a period of 15 years. 2. 2. Underlying organic heart disease was found in 131 patients (75 per cent), all of whom represented, in general, an older age group than the patients with normal hearts. Arteriosclerosis and hypertension were the most frequent etiologies, being found in 88 (67 per cent) of the cases with diseased hearts. 3. 3. Of the supraventricular tachycardias in patients with organic heart disease, 45 (35 per cent) were complicated by second and third degree atrioventricular block, which usually could be attributed to complicating digitalis intoxication. 4. 4. Serious clinical symptoms were only rarely observed in patients with normal hearts. In contrast, chest pain, heart failure, and shock were frequent manifestations of the disorder in organic heart disease. 5. 5. Aberration of the QRS complexes during tachycardia was as frequent in normal hearts as in diseased hearts. Atrial rates were noted to be higher in the group with atrioventricular block, resulting in confusion of the electrocardiographic diagnosis with slow atrial flutter. The diagnostic criteria are outlined. 6. 6. The usual methods of termination, utilizing carotid sinus pressure mechanical reflex increase in vagus tone, were much less effective in the patients with organic heart disease than in normal patients. If such measures failed, digitalis therapy was found to be the most effective method if it was not a factor in the production of the rhythm disorder. 7. 7. Paroxysmal supraventricular tachycardia with atrioventricular block presents a special problem in therapy. There is usually gratifying restoration to sinus rhythm upon discontinuation of digitalis and administration of potassium salts. 8. 8. The prognosis of these disorders depends upon the underlying etiology. In myocardial infarction it is uniformly poor, but a few cases can be salvaged by proper therapy. 9. 9. Methods of management in other unusual situations, and prevention of recurrences are discussed.

Spatial vector electrocardiography: Method and average normal vector of P, QRS, and T in space

Abstract A method for spatial vector electrocardiography from 12 routine leads by means of a model is described. It is found to be useful as a practical method for quick and approximate determination and in clinical teaching. Presented are the average normal spatial vectors of P, QRS, and T obtained in this model from 1,000 electrocardiograms classified as normal under the criteria of F. N. Wilson. The average normal vectors of P, QRS, and T in space are directed to the left and downward, P and T being directed anteriorly, and QRS, posteriorly. The angle between QRS and T was 60 degrees; the angle between P and the plane defined by QRS and T was 15 degrees. The problems of the spatial counterpart of the Einthoven assumption is discussed on the basis of previous experimental work. It is anticipated that spatial vector electrocardiography may be studied on a physically founded basis by means of the Burger lead-vector concept while the electrodes on the patient remain at the routine 12-lead positions. On the average this will give more nearly accurate results than those based on the spatial counterpart of the Einthoven assumption. The present model may be adapted easily in such study for convenient visual correlation as described above.

A vector study of the delta wave in “nondelayed” conduction☆

Abstract 1. 1. At present, the electrocardiographic syndrome discussed could be adequately described as a “nondelayed” conduction. 2. 2. The directional incidence of the delta wave vector and remaining QRS vector, as well as the angular incidence between them at the RLF plane, were studied. The study was based on 50 limb lead electrocardiograms of “nondelayed” conduction. 3. 3. The left basal ventricular wall of either ventricle may possibly be the frequent site of the premature, weak, localized contraction associated with the delta wave vector. 4. 4. A leftward tendency of the remaining QRS activation was observed.

The two main QRS vectors in the frontal plane in electrocardiograms of complete left bundle branch block

Abstract 1. The incidence in the various directions of the two main QRS vectors in the frontal plane in LBBB was investigated. The first main QRS vectors had nearly the same directions as the normalAˆQRS, the second one occupied the left upper quadrant. The angles formed by the two vectors usually did not exceed 90°, and was 45° on the average. 2. The incidence of LBBB was about 1 per cent; its incidence to RBBB was as 1 to 2. 3. The general direction of activation of a single normal ventricle, either left or right, was nearly the same as normalAˆQRS. The route of activation of a blocked ventricle, either left or right, was abnormally altered; toward left in LBBB, toward right in RBBB.

The Burger triangle in curve from

Abstract The average Burger triangle gives more accurate results than the Einthoven triangle. This paper described the average Burger triangle in curve form. It is easier to use than the triangle itself. It was pointed out that the curves may be used together with the curves derived from the Einthoven triangle to obtain simultaneous results from both triangles. The physician may check each time at a glance the inaccuracy of the Einthoven triangle in individual electrocardiograms.

A further study of cardiac vectors in the frontal plane

Abstract In a previous study we analyzed cardiac vectors in the frontal plane from several hundred limb-lead electrocardiograms. 1 They were selected at random from routine 12-lead electrocardiograms which were classified either as being normal or as indicating right ventricular hypertrophy, left ventricular hypertrophy, complete right bundle branch block, or complete left bundle branch block. The classification of the electrocardiograms was based on the criteria established by Frank N. Wilson and associates. This study is a continuation of the previous one. It concerns cardiac vectors in the frontal plane from a total of 400 limb-lead electrocardiograms. They were selected at random, there being 100 cases of old anterior myocardial infarction (AMI), 100 cases of old posterior myocardial infarction (PMI), 100 cases of acute pericarditis (AP), and 100 cases of digitalis effect in left ventricular hypertrophy (DE). In each case the classification was supported by clinical data. The recording instrument was a Sanborn Viso-Cardiette.

Relation between S-T segment elevation and experimental myocardial oxygen gradient

Myocardial oxygen gradient was altered variously by means of gas mixture inhalation in acute coronary artery occlusion in dog. This was correlated with the S-T segment elevation in electrocardiograms recorded in a bipolar subepicardial lead across the pink area and cyanotic area of the myocardium. The electrocardiograms revealed a positive relation between them, that is, the S-T segment increased in height with the increasing of oxygen gradient, and decreased in height with the decreasing of gradient. Occasionally there were also observed S-T segment electrical alternans and the merging of the S-T segment. Implications were briefly discussed.