Activation of the reed switch results in a preset pacing rate and may theoretically induce VF or aggravate myocardial ischemia.
Right ventricular cardiac output significantly decreased at pacing rates of 60, 90, 120, 180, 210, 240, and 270 beats/min (P <.01), although no significant difference was found at the pacing rate of 150 beats/min compared with control.
Systolic aortic pressure significantly decreased at pacing rates of 60, 90 and 240 beats/min (P <.01), and central venous pressure was increased significantly at a pacing rate of 60 beats/min (P <.01) compared with the control.
Objective: This study was undertaken to determine the optimum ventricular pacing rate at which the optimal cardiac function can be attained in fetal lambs with complete atrioventricular block.
The results show that while the existing model tends to overestimate or underestimate the vibration levels depending on the pacing rate, the new model provides statistically reliable estimations of the vibration responses.
Application of this protocol in in vitro guinea-pig left-ventricular myocytes demonstrated that both voltage- and calcium-driven instabilities underlie alternans, and that the relative contributions of the two systems change as a function of pacing rate.
At a 1Hz pacing rate, steady state action potential duration was nearly doubled (313 ms, WT vs. 588 ms, F1473C) in the mutant (Figure 8A).
Simulations suggest both an increase in pacing rate and Na+ channel blockers as beneficial in recovering channel function consistent with the successful arrhythmia management obtained by pacing and high-dose mexiletine.
The pacing rate is 60 bpm.
Based on a fixed external pacing rate no changes in HR were observed.
Thus, of seven hearts, only one then showed an episode of sVT at a pacing rate of 12 Hz.
