Table 1. Electrocardiograph parameters of C57BL/6 mice infected with the Colombian T. cruzi strain.
| Groups | Heart rate1 (bpm) | PR interval (ms) | P duration (ms) | QRS duration (ms) | QTc (ms) | Cardiac conduction (% of mice)2 | Frequency of afflicted mice (%) |
| Noninfected | 637±70.7 | 35±1.1 | 9±2.1 | 11±1.5 | 77±5.7 | ART (0%), AVB1 (0%), AVB2 (0%) | 0 |
| T. cruzi 30 dpi | 491±36.2 | 41±2.8 | 13±1.2 | 13±2.3 | 81±5.1 | ART (43%), AVB1 (43%), AVB2 (28%) | 70 |
| T. cruzi 60 dpi | 496±51.3* , 3 | 46±4.2* | 14±3.7 | 14±0.8 | 86±6.2 | ART (57%), AVB1 (43%), AVB2 (43%) | 86 |
| T. cruzi 90 dpi | 450±61.6** | 47±6.3* | 14±0.9 | 13±1.2 | 88±13.3* | ART (67%), AVB1(43%), AVB2 (57%) | 100 |
| T. cruzi 120 dpi | 433±64.4*** | 45±4.7* | 14±3.0 | 13±1.1 | 89±11.6** | ART (72%), AVB1 (28%), AVB2 (72%) | 100 |
1
ECG parameters were evaluated using the following standard criteria: (i) heart rate (monitored by beats per minute (bpm), and (ii) the variation of the P wave and PR, QRS and corrected QT intervals (QTc), all measured in milliseconds (ms). ART, arrhythmia; AVB1, first-degree atrioventricular block; AVB2, second-degree atrioventricular block.
2
This data represent three independent experiments, with 7–8 infected mice/group. Three sex- and age-matched noninfected controls were analyzed in all experimental time points. The results were pooled in one representative group of 12 noninfected controls per experiment.
3
Significant differences
*: , p<0.05;
**: , p<0.01;
***: , p<0.001 between the values for noninfected and T. cruzi-infected groups of mice.