DOES CARDIAC RHYTHM ALONE DETERMINE HUMAN BLOOD PRESSURE VARIATIONS?
Carl J. Wiggers M.D.1 1 From the Physiological Laboratory of Cornell University Medical College, New York. Changes in cardiac rhythm are not the only determinants of blood pressure variations in man. They play a part in the variations of systolic and diastolic pressures, the relative importance of which depends on the degree of arhythmia present and on the depth of respiration which, in itself, causes the systolic and diastolic pressures to decrease during inspiration and increase during expiration. No degree of rate variation can be regarded as a type. The cases range from those in which respiration governs the change of pressures entirely through those where more or less complicated mixtures of heart rate and respiratory influences intermingle to those in which extreme cardiac variations alone determine the pressure changes. The emphatic insistence of Henderson and his collaborators that heart rate changes play a more important part than is commonly recognized in man is true in many
