LETTER TO THE EDITOR
Pulse wave reflection in pulmonary hypertension: Reply
Yasunori Nakayama, MDa
a Department of Cardiology, Ishikiriseiki Hospital, 18-28, Yayoi, Higashiosaka City, Osaka, 579-8026, Japan
We appreciate the interest by Chemla et al. in our study concerning the analysis of pulmonary arterial reflection in the differential diagnosis of chronic pulmonary thromboembolism (CPTE) and primary pulmonary hypertension (PPH) (1). We used a fluid-filled system to analyze arterial pressure waveform in previous studies (1–3). If we had used a high-fidelity pressure transducer, the recorded pressure waveform would have been more accurate. As a high-fidelity catheter manometer is an expensive and intricate system, high-fidelity measurement makes the analysis of reflection waveform impractical in a clinical setting (4). To give the analysis of pulmonary arterial reflection the clinical implications, we measured inflection point using a fluid-filled recording system and examined whether the inflection time was correctly defined. To quantify the artery reflection, we used the augmentation index and inflection time (1,2). Both the augmentation index and the inflection time using a fluid-filled recording system were reliable and unchanged by repeated measurements. The fact that we could differentiate CPTE from PPH using the fluid-filled system should be interpreted not as a weakness but as a strength of the study (1,2).
Many workers have investigated the analysis of pulmonary arterial reflection, and with controversial results (1,2). Main factors contributing to this diversity include: 1) the effect of different ethnic groups; 2) the effect of different measuring systems; and 3) the effects on aging, the treatments and vasodilator severity of pulmonary hypertension. Body mass index in the general Japanese population is smaller than in Europeans and Americans. Thus, it is natural that our results using fluid-filled catheters in Japanese subjects are inconsistent with the results using high-fidelity catheters in European subjects, to greater or lesser degree. Furthermore, the effects on aging, the treatments and vasodilator severity of pulmonary hypertension modify pulmonary arterial reflection. Comparison of our study with the study of Chemla et al. produces controversial results without adjustment for these factors.
In conclusion, measurement of pulmonary artery pressure by fluid-filled catheters is an inexpensive and simple procedure compared to measurement by high-fidelity catheter. As analysis of pulmonary artery reflection added to pulsatility of pulmonary artery pressure waveform can help in differentiating between CPTE and PPH, measurement of pulmonary reflection waveform by fluid-filled catheters is an extremely attractive clinical tool.
 |
References
|
|---|
1. Nakayama Y, Nakanishi N, Hayashi T, et al. Pulmonary artery reflection for differentially diagnosing primary pulmonary hypertension and chronic pulmonary thromboembolism. J Am Coll Cardiol. 2001;38:214–218[Abstract/Free Full Text]
2. Nakayama Y, Nakanishi N, Sugimachi M, et al. Characteristics of pulmonary artery pressure waveform for differentially diagnosing chronic pulmonary thromboembolism and primary pulmonary hypertension. J Am Coll Cardiol. 1997;29:1311–1316[Abstract]
3. Nakayama Y, Tsumura K, Yamashita N, Yoshimaru K, Hayashi T. Pulsatility of ascending aortic pressure waveform is a powerful predictor of restenosis after percutaneous transluminal coronary angioplasty. Circulation. 2000;101:470–472[Abstract/Free Full Text]
4. Castelain V, Hervé P, Lecarpentier Y, Duroux P, Simonneau G, Chemla D. Pulmonary artery pulse pressure and wave reflection in chronic pulmonary thromboembolism and primary pulmonary hypertension. J Am Coll Cardiol. 2001;37:1085–1092[Abstract/Free Full Text]
|
Top
References