Catheter-based examination for pulmonary microcirculatory function in patients with pulmonary hypertension

Figures

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  Fig 1. Schema of catheter-based examination for pulmonary microcirculatory function. Adenosine was administered to patients with an infusion pump. All measurements and calculations were automatically run using computer software. PA = pulmonary artery; Pp = proximal pulmonary artery pressure; Pd = distal pulmonary artery pressure; Tmn = mean transit time; PFR = pulmonary flow reserve; PIMR = pulmonary index of microcirculatory resistance; and PRRR = pulmonary resistive reserve ratio.

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  Fig 2. Representative X-ray frontal images during cardiac catheterization. (A) The pulmonary arteries in the lower lobe of the right lung are shown using contrast medium. The suitable pulmonary artery to facilitate the placement of a temperature- and pressure-sensor guidewire was selected with an angiogram. The white arrows indicate a guiding catheter used to inject the contrast medium and deliver the guidewire. The catheter was delivered from the inferior vena cava to the right central pulmonary artery. (B) The white arrow indicates the guidewire placed distally to the pulmonary artery to measure blood pressure and mean transit times in the artery. (C) A final angiogram following the above measurements indicated no occurrence of vascular complications in the artery.

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  Fig 3. Change in mean transit time in the pulmonary artery with or without adenosine-induced hyperemia. (A) Change in measured values of mean transit time (Tmn) in a pulmonary artery in 19 patients who received intravenous administration of adenosine for pulmonary hyperemia. The Tmn measurement was performed three times at each of the six dosages of adenosine (0, 50, 100, 150, 200, and 250 μg∙kg−1∙min−1). (B) Change in difference values in Tmn was measured at the second consecutive dosage in the six dosages of adenosine. Difference values are shown by both scatter and box plots. Numerical values noted above each box plot indicate the median (upper quartile, lower quartile) of the different values. *: p = 0.005.

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  Fig 4. Side effects of adenosine continuously administered into the peripheral vein in 19 patients with pulmonary hypertension.

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  Fig 5. Comparison between pulmonary index of microcirculatory resistance and pulmonary vascular resistance. Abbreviations as in Tables 1 and 3. β indicates the standardized regression coefficient resulting from a stepwise multiple regression analysis to test the relationship between PIMR or PVR and serum biomarkers, hemodynamics, respiratory function, and functional exercise capacity.