Table 1: Pooled Experimental Data of Short-term Variability (STV) of Repolarisation of the Left Ventricular Monophasic Action Potential Duration and QTc Prior to Torsades de Pointes STVarrhythmic and Arrhythmic QTc, Compared With Baseline in the Chronic Atrioventricular Block Dog Model.
STVLV, MAPD (ms) | ΔSTV | QTc (ms) | ΔQTc | ||||||
Baseline | Arrhythmic | Absolute (ms) | Relative (%) | Baseline | Arrhythmic | Absolute (ms) | Relative (%) | ||
Overall | 1.28 ± 0.65 | 3.30 ± 1.79** | 2.01 ± 1.59 | 182.8 ± 145.3 | 398.60 ± 59.80 | 557.6 ± 69.43** | 159.1 ± 72.22 | 42.04 ± 22.87 | |
AS | Low (n=12) | 0.98 ± 0.72 | 1.71 ± 1.18* | 0.73 ± 0.70 | 90.83 ± 90.28 | 397.20 ± 68.89 | 555.1 ± 68.52** | 157.9 ± 67.60 | 42.03 ± 21.95 |
Intermediate (n=25) | 1.34 ± 0.61 | 3.78 ± 2.02** | 2.44 ± 1.87 | 211.10 ± 155.10*** | 400.60 ± 57.82 | 562 ± 70.20** | 161.60 ± 82.22 | 42.83 ± 26.67**** | |
High (n=27) | 1.37 ± 0.63 | 3.55 ±1.40** | 2.18 ± 1.32 | 197.50 ± 143.60*** | 397.40 ± 59.70 | 554.6 ±71.49** | 157.2 ± 66.73 | 41.31 ± 20.14**** |
Data are expressed as mean ± standard deviation. *p<0.01, **p<0.0001 compared with the same electrophysiological parameter in baseline, ***p<0.05 compared with the same electrophysiological parameter in the low arrhythmia score group, ****p<0.0001 compared to relative ΔSTV of the same arrhythmia score group. All comparisons between the same electrophysiological parameter were not significant between the intermediate and high arrhythmia score group. Statistics between STV and QTc have not been calculated for absolute Δ, because these are not comparable. CAVB = chronic atrioventricular block; LV = left ventricular; MAPD = monophasic action potential duration; STV = short-term variability of repolarisation.