PMC5733209_01
ECG, arterial pressure, and pulse pressure during pacemaker rhythm. The recording was taken shortly after the patient's arrival to the ICU. Pacemaker spikes can be seen before every heartbeat, and the arterial pressure and pulse pressure indicate substantial fluctuations. The recordings were analyzed offline, and a pulse pressure diagram was also added.
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On admission, he was hemodynamically unstable with marked arterial pressure fluctuation noted on the first ECG and arterial pressure curve recordings (Figure 1).
Relationship of sinus and paced cardiac activity and its effect on arterial pressure. The ECG strip shows a paced ventricular "regular" rhythm, where atrioventricular dissociation is still present. The small arrows indicate atrial activity ("A"). The coincidence of normal AV sequence results in substantial arterial pressure augmentation (indicated by the thick arrows). For more details, read the text.
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A more detailed evaluation of the ECG and blood pressure recordings revealed an obvious interference between the paced ventricular and spontaneous atrial (sinus) activities (Figure 2).
Change of pulse pressure variation (PPV) during sinus and pacemaker rhythm. ECG, arterial pressure, and noncalibrated pneumobelt signals were recorded during the dynamic preload test. While the initial segment of the arterial pressure panel during sinus rhythm indicates minimal changes in pulse pressure (PP) resulting in borderline PPV, the switch to ventricular pacemaker rhythm is accompanied by enormous pressure fluctuations and a severalfold increase in PPV. The straight lines indicate the 3 breathing cycles detected by the pneumobelt during the first and second part of recording. Based on the pneumobelt signal, the arterial pressure swings occurring during the pacemaker rhythm seem to be unrelated to the ventilation.
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Furthermore, the alternative sinus and VVI-paced periods allowed comparison of the hemodynamic responses during these two different rhythms (Figure 3). In addition to the drop in mean pulse pressure from an already low value of 30 mmHg to an even lower value of 20 mmHg, this change was accompanied by a large increase in PPV, from 13% to 58% (Figure 3).