PMC8570904_01
(a) Daily averaged estimated pulmonary artery diastolic pressure (ePAD). (b) Intrathoracic impedance (Omega) with reference line (dotted). (c) Diuretic dose (bumetanide, mg/day). AE: adverse event. Dashed lines indicate loss of long-term trend data because of remote patient hospitalization and noncompliance.
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Retrospective analyses of the Chronicle and InSync Sentry  device data confirmed this favorable response: during the first month, ePAD decreased to 12 mmHg while intrathoracic impedance increased (Figure 1, Table 1). As this resulted in a sudden drop of impedance from 59 Omega to 50 Omega (Figure 1, Table 1) without major change in ePAD, we speculated that the increase in lung water content secondary to the bronchitis rather than fluid overload due to heart failure accounted for this observation. Therefore, the dose of the diuretic (bumetanide) could be further decreased to 1 mg/day and beta blockade was restarted (carvedilol; 6.25 mg/twice daily) (Figure 1).
(a) ePAD (mmHg). (b) Intrathoracic impedance (Omega) with reference line (dotted). (c) Diuretic dose (bumetanide, mg/day). AE: adverse event. Dashed line indicates loss of ePAD data.
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However, in December 7th, uptitration of the diuretic regimen to the initial dose (2 mg/day) because of worsening heart failure did not increase impedance and even resulted in a paradoxical increase in ePAD from 28 to 35 mmHg, together with worsening renal function and the development of acute heart failure (AE2) (Figure 2). Over the following months, a typical sawtooth pattern of intrathoracic impedance and ePAD (Figure 2) was noted with higher ePAD and lower impedance the days before dialysis.