Figure 1.
Representative image of SR and RVA pacing for LV rotation and twist in the same dog.
As shown by the graph, the degree of rotation and twist was smaller at RVA pacing than SR, and the apical TPR, RSI, and TPT of RVA pacing were longer compared to SR. SR: sinus rhythm; RVA: right ventricular apex; TPR: time to peak rotation; TPT: time to peak twist; RSI: rotational synchronization index.
Table 1.
Parameters of TPT, TPR and RSI adjusted by the R–R interval, echocardiography, MAPSE, TAPSE, left ventricular pressure and heart rate at SR and pacing.
Figure 2.
The QRS morphology of the same experimental dog at SR and different pacing side at I and II of ECG.
As compared with HB and RA pacing, the QRS morphology was quite different at all involved ventricular pacing. SR: sinus rhythm; RA: right atrium; RVA: right ventricular apex; RVOT: right ventricular outflow tract; HB: His bundle; LVA: left ventricular apex; LVS: left ventricular septum; RARV: RA and RVA.
Figure 3.
The QRS duration of SR at different pacing side.
* P<0.05 vs. SR; †P<0.05 vs. pacing at RA; ‡ P<0.05 vs. pacing at HB. SR: sinus rhythm; RA: right atrium; RVA: right ventricular apex; RVOT: right ventricular outflow tract; HB: His bundle; LVA: left ventricular apex; LVS: left ventricular septum; RARV: RA and RVA.
Figure 4.
Changes in parameters of apical rotation, basal rotation and twist during different cardiac pacing and SR (Special Note: the basal dates are its absolute value).
* P<0.05 vs. SR; †P<0.05 vs. pacing at RA; ‡ P<0.05 vs. pacing at HB. SR: sinus rhythm; RA: right atrium; RVA: right ventricular apex; RVOT: right ventricular outflow tract; HB: His bundle; LVA: left ventricular apex; LVS: left ventricular septum; RARV: RA and RVA.
Figure 5.
Changes in parameters of apical TPR, basal TPR, TPT, and RSI during different cardiac side pacing and SR.
* P<0.05 vs. SR; †P<0.05 vs. pacing at RA; ‡ P<0.05 vs. pacing at HB. SR: sinus rhythm; RA: right atrium; RVA: right ventricular apex; RVOT: right ventricular outflow tract; HB: His bundle; LVA: left ventricular apex; LVS: left ventricular septum; RARV: RA and RVA; TPR: time to peak rotation; TPT: time to peak twist; RSI: rotational synchronization index.