Pulsus Alternans
By this term is meant that condition of pulse in which, though the rhythm is normal, strong and weak pulsations alternate. White [Footnote: White: Am. Jour. Med. Sc., July, 1915, p. 82.] has shown that this condition is not infrequent, as demonstrated by polygraphic tracings. He found such a condition present In seventyone out of 300 patients examined, and he believes that if every decompensating heart with arrhythmia was graphically examined, this condition would be frequently found. The alternation may be constant, or it may occur in phases. It is due to a diminished contractile power of the heart when the heart muscle has become weakened and a more or less rapid heart action is present.
Gordinier [Footnote: Gordinier: Am. Jour. Med. Sc., February, 1915, p. 174.] finds that most of these patients with alternating pulse are suffering from general arteriosclerosis, hypertension, chronic myocarditis, and chronic nephritis, in other words, with cardiovascularrenal disease. He finds that it frequently occurs with Cheyne-Stokes respiration, and continues until death. He also finds that the condition is not uncommon in dilated hearts, especially in mitral disease, and with other symptoms of decompensation.
White found that about half of his cases of pulsus alternans showed an increased blood pressure of 160 mm. or more; 62 percent. were in patients over 50 years of age, and 69 percent. were in men. Necropsics on patients who died of this condition showed coronary sclerosis and arteriosclerotic kidneys.
The onset of dyspnea, with a rapid pulse, should lead one to suspect pulsus alternans when such a condition occurs in a person over 50 with cardiovascular-renal disease, arid with signs of decompensation, and also when such a condition occurs with a patient who has a history of angina pectoris.
While the forcefulness of the varying beats of an alternating pulse may be measured by blood pressure instruments by the auscultatory method, White and Lunt [Footnote: White, P. D. and Lunt, L. K.: The Detection of Pulsus Alternans, THE JOURNAL A. M. A., April 29, 1916, p. 1383.] find that in only about 30 percent. of the cases, the graver types of the condition, is this a practical procedure.
Pulsus alternans, except when it is very temporary, Gordinier finds to be of grave import, as it shows myocardial degeneration, and most patients will die from cardiac insufficiency in less than three years from the onset of the disturbance.
The treatment is rest in bed and digitalis, but White found that in only four patients out of fifty-three so treated was the alternating pulse either "diminished or banished." In a word, the only treatment is that of decompensation and a dilated heart, and when such a condition occurs and is not immediately improved, the prognosis is bad, under any treatment.