Mohan M, Anandh B, Thombre D P, Surange S G, Chakrabarty A S
Department of Physiology, Jawaharlal Institute of Postgraduate Medical Education and Research, Pondicherry.
Indian J Physiol Pharmacol. 1987 Jul-Sep;31(3):211-7.
Effect of change in body posture on cardiac electrical axis has not been well documented. Hence the present work was undertaken to study the effect of passive head-up and head-down postures on ventricular QRS axis and heart rate of anesthetised mice. During head-up posture, there was a statistically significant (P less than 0.02) increase in heart rate whereas during head-down posture, the heart rate decreased insignificantly. These changes in heart rate can be explained on the basis of synus and aortic nerve mediated baroreceptor reflexes. Ventricular QRS axis showed a significant increase (P less than 0.02) during head-up posture and an insignificant decrease during head-down posture. A change in the posture is likely to produce a change in anatomical orientation of heart within the thorax resulting in alteration of electrical axis of the heart.
