VALUES OF THE ELECTROCARDIOGRAPHIC WAVES IN SOUTH AMERICAN RIVER TURTLES (Podocnemis expansa Schweigger, 1812) (TESTUDINES).

S. F. M. CARVALHO, A. L. Q. SANTOS

Abstract


Electrocardiographic waves were measured in thirty healthy Podocnemis expansa with no chemical restraint. Lead III traces calibrated at 50 mm/s and 10 mm/mV were recorded through five cutaneous electrodes. The electrocardiogram consisted in P waves, QRS complexes, and T waves. This pattern was similar to the electrocardiogram documented for other chelonian species, and differs from mammalian electrocardiogram in having lower amplitude waveforms, longer repolarization phase (longer ST and QT intervals), and shorter TP interval. The mean and standard deviation of electrocardiographic waves, in seconds, were: P = 0.1 (±0.02), PR = 0.36 (± 0.1), QRS = 0.1 (± 0), ST = 0.94 (±0.15), QT = 1.04 (± 0.17). The mean and standard deviation of the wave?s amplitudes, in mV, were: P = 0.1 (±0), QRS = 0.29 (± 0.03), ST = 0.68 (± 0.17), T = 0.38 (±0.11). The heart rates ranged widely from 16.39 to 54.54 beats per minute (29.81 ± 8.29).
KEY-WORDS: Electrocardiography. Heartbeat. Podocnemis expansa. South American river turtle.



DOI: http://dx.doi.org/10.15361/2175-0106.2006v22n2p117-121