Doppler tissue imaging in assessment of pulmonary hypertension-induced right ventricle dysfunction

• Published in: American journal of physiology. Heart and circulatory physiology 2005-12, Vol.289 (6), p.H2450-H2455
• Main Authors: Boissiere, Julien, Gautier, Mathieu, Machet, Marie-Christine, Hanton, Gilles, Bonnet, Pierre, Eder, Veronique
• Format: Article
• Language: English
• Subjects: Animals; Echocardiography, Doppler - methods; Hypertension, Pulmonary - complications; Hypertension, Pulmonary - diagnostic imaging; Image Interpretation, Computer-Assisted - methods; Life Sciences; Male; Rats; Rats, Wistar; Ventricular Dysfunction, Right - diagnostic imaging; Ventricular Dysfunction, Right - etiology
• ISSN: 0363-6135; 1522-1539
• DOI: 10.1152/ajpheart.00524.2005

1 Laboratoire de Physiologie de la Paroi Artérielle EA3852, Faculté de Médecine, IFR 135 Imagerie Fonctionnelle, Université François Rabelais, Tours; and 2 Pfizer Global Research and Development, Amboise, France Submitted 19 May 2005 ; accepted in final form 17 July 2005 We aimed to assess the accuracy of Doppler tissue imaging (DTI) in detecting right ventricle (RV) dysfunction and electromechanical coupling alteration following pulmonary hypertension (PHT) in rat. PHT was induced by chronic hypoxia exposure (hypoxic PHT) or monocrotaline treatment (monocrotaline PHT). In both PHT models, we observed transparietal RV pressure increase and remodeling, including hypertrophy and dilation. Conventional echocardiography provided evidence for pulmonary outflow impairment with midsystolic notch and acceleration time decrease in PHT groups (21.7 ± 1.6 and 13.2 ± 2.9 ms in hypoxic and monocrotaline PHT groups vs. 28.1 ± 1.0 ms in control). RV shortening fraction was decreased in the monocrotaline PHT group compared with the hypoxic PHT and control groups. Combining conventional Doppler and DTI was more helpful to detect RV diastolic dysfunction in the monocrotaline PHT group (E/Ea ratio = 17.0 ± 1.4) compared with the hypoxic PHT and control groups (11.5 ± 0.7 and 10.2 ± 0.4, respectively). Tei index measured using DTI highlighted global RV dysfunction in the monocrotaline PHT group (1.36 ± 0.24 vs. 0.92 ± 0.05 and 0.86 ± 0.05 in the hypoxic PHT and control groups, respectively). Q-S m time measured from the onset of Q wave to the onset of DTI S m wave was increased in both PHT groups. PHT-induced electromechanical coupling alteration was confirmed by in vitro activation-contraction delay measurements on isolated RV papillary muscle, and both Q-S m time and activation-contraction delay were correlated with PHT severity. We demonstrated that Q-S m time measured in DTI was an easily and convenient index to detect early RV electromechanical coupling alteration in both moderate and severe PHT. echocardiography; hypertrophy; right ventricular remodeling Address for reprint requests and other correspondence: V. Eder, Faculté de Médecine, Laboratoire de Physiopathologie de la Paroi Artérielle (LABPART), 10 Boulevard Tonnellé, BP 3223, 37032 Tours Cedex 1, France (e-mail: eder{at}med.univ-tours.fr )