Search

Electrocardiographic analysis of the P wave occurring in a series of 36 patients with benign atrial fibrillation compared with similar analysis in a control group of normal subjects is reviewed. No statistically significant differences were noted in the Macruz index, height of the P wave in lead II, or P initial force V 1 when compared to controls. However, the values obtained for P terminal force V 1 , P total force V 1 (algebraic product of the total duration and total amplitude of the P wave in lead V 1 ), and the ratio of both these values in the patient group were significantly different from the control group. The existence of a minor intra-atrial conduction block in patients with benign atrial fibrillation is suggested.

Certain interesting gross pathologic features of the heart and aorta as seen in routine autopsy specimens of patients who die from malignancy and other cachectic states have been correlated with clinical, electrocardiographic and roentgenologic features and collectively described under the term “cachetic heart.” The pathogenesis of this entity remains obscure at the present time. A few postulates are discussed in light of certain observations made in experimental animals in which cancer was induced. At present, the entity is usually diagnosed in retrospect. However, with better recognition of certain diagnostic criteria outlined in this report, it should not be difficult to establish the diagnosis during life.

The use of electrocardiographic leads taken during inspiration has long been advocated to aid in evaluation of possible P wave, QRS, and T wave abnormalities. Their use in the uncovering of rhythm abnormalities has not been emphasized. Careful observation of leads III and AVF taken during the act of ispiration for a period of one month revealed that the greatest value of these leads (III-2 and AVF-2) was in the provocation and clarification of cardiac arrhythmias. The clinical implications of these findings are discussed.

V A R I A T I O N IN THE TIME INTERVALS OF waves of atrial activity (P-P interval) has been observed to occur frequently in both complete and incompkte atrioventricular block and also in interference diisociation.'" The w a l observation is that those P-P intervals containing QRS complexes are shorter in duration than those not containing a ventricular deflection. Rarely the relationship is revelsed so that the P-P intervals without QRS complexes are the shorter ones. This phenomenon has been termed ventriculophasic sinus arrhythmia.'"' The mechanism of such alternating lengths of the sinus cycles is not known, although the rule of arterial vagal presoreceptors, mechanical traction on the atrium, and alternating changes in sinus

Vectorcardiographic observations in a patient exhibiting postextrasystolic T wave changes associated with interpolated extrasystoles were undertaken. The T wave changes observed were found to be “primary” and not secondary to aberrant ventricular depolarization. It is suggested that hemodynamic factors may play a role in the genesis of these T wave changes.