| 1. |
- Ahlström, Christer, 1977-, et al.
(författare)
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Noninvasive investigation of blood pressure changes using the pulse wave transit time : A novel approach in the monitoring of hemodialysis patients
- 2005
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Ingår i: Journal of Artificial Organs. - : Springer Science and Business Media LLC. - 1434-7229 .- 1619-0904. ; 8:3, s. 192-197
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Tidskriftsartikel (refereegranskat)abstract
- Severe blood pressure changes are well known in hemodialysis. Detection and prediction of these are important for the well-being of the patient and for optimizing treatment. New noninvasive methods for this purpose are required. The pulse wave transit time technique is an indirect estimation of blood pressure, and our intention is to investigate whether this technique is applicable for hemodialysis treatment. A measurement setup utilizing lower body negative pressure and isometric contraction was used to simulate dialysis-related blood pressure changes in normal test subjects. Systolic blood pressure levels were compared to different pulse wave transit times, including and excluding the cardiac preejection period. Based on the results of these investigations, a pulse wave transit time technique adapted for dialysis treatment was developed and tried out on patients. To determine systolic blood pressure in the normal group, the total pulse wave transit time was found most suitable (including the cardiac preejection period). Correlation coefficients were r = 0.80 ± 0.06 (mean ± SD) overall and r = 0.81 ± 0.16 and r = 0.09 ± 0.62 for the hypotension and hypertension phases, respectively. When applying the adapted technique in dialysis patients, large blood pressure variations could easily be detected when present. Pulse wave transit time is correlated to systolic blood pressure within the acceptable range for a trend-indicating system. The method's applicability for dialysis treatment requires further studies. The results indicate that large sudden pressure drops, like those seen in sudden hypovolemia, can be detected. © The Japanese Society for Artificial Organs 2005.
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| 2. |
- Imamura, Teruhiko, et al.
(författare)
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Acute pulmonary vasoreactivity test with sildenafil or nitric monoxide before left ventricular assist device implantation
- 2013
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Ingår i: Journal of Artificial Organs. - : Springer Verlag (Germany). - 1434-7229 .- 1619-0904. ; 16:3, s. 389-392
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Tidskriftsartikel (refereegranskat)abstract
- There has been no established medical therapy to ameliorate pulmonary hypertension (PH) owing to left heart disease (LHD-PH). It has recently been shown that the left ventricular assist device (LVAD) can improve LHD-PH and therefore has the potential to become a major bridge tool for heart transplantation (HTx). However, some patients still have persistent PH even after LVAD treatment. It is essential to demonstrate the reversibility of end-organ dysfunction, including PH, prior to implantable LVAD treatment, especially in Japan, because implantable LVAD treatment is indicated only as bridge to transplantation. Here we report a patient with LHD-PH whose PH was demonstrated to be reversible by the acute pulmonary vasoreactivity test (APVT) with nitrogen monoxide (NO) and the phosphodiesterase-5 inhibitor sildenafil. Both inhaled NO and sildenafil reduced pulmonary vascular resistance, but pulmonary capillary wedge pressure was increased by NO, which was conversely decreased under increased cardiac output by sildenafil. After the patient was listed as an HTx recipient, pulmonary vascular resistance recovered down to an acceptable range with LVAD treatment. Based on these findings, we suggest that the APVT with sildenafil may be a useful and safe tool to predict improvement of PH after LVAD treatment.
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| 3. |
- Imamura, Teruhiko, et al.
(författare)
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Bosentan improved persistent pulmonary hypertension in a case after implantation of a left ventricular assist device
- 2013
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Ingår i: Journal of Artificial Organs. - : Springer. - 1434-7229 .- 1619-0904. ; 16:1, s. 101-104
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Tidskriftsartikel (refereegranskat)abstract
- No medical treatment has been established to ameliorate pulmonary hypertension (PH) due to left heart disease. Heart transplantation (HTx) is thus far the definitive therapy for stage D heart failure, but concomitant PH is one of the major risk factors for death after HTx. Recently, implantation of a left ventricular assist device (LVAD) has been reported to improve PH and has become a major bridge tool for HTx. We experienced a rare case with persistent PH even after the implantation of a continuous-flow LVAD. The administration of an endothelin receptor antagonist, bosentan, significantly decreased pulmonary vascular resistance. Combination therapy with LVAD implantation and anti-PH medication may be useful for patients with stage D heart failure complicated with severe PH.
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| 4. |
- Imamura, Teruhiko, et al.
(författare)
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How to demonstrate the reversibility of end-organ function before implantation of left ventricular assist device in INTERMACS profile 2 patients?
- 2012
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Ingår i: Journal of Artificial Organs. - : Springer. - 1434-7229 .- 1619-0904. ; 15:4, s. 395-398
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Tidskriftsartikel (refereegranskat)abstract
- For the time being, in Japan, two recently approved implantable ventricular assist devices (VADs) are indicated only when a patient has been listed for heart transplantation or approved to be eligible for heart transplantation by in-hospital committee. The reversibility of end-organ dysfunction must be expected before VAD implantation, but it is often hard to prove during worsening clinical status. We report two patients whose end-organ dysfunction had been eventually demonstrated to be reversible by invasive procedures such as transluminal liver biopsy or transient insertion of intra-aortic balloon pumping.
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