Usefulness of a New Doppler Index for Assessing Both Ventricular Functions and Pulmonary Circulation in Newborn Piglet With Hypoxic Pulmonary Hypertension

Sugiura, T.; Suzuki, Satoshi; Hussein, Mohamed Hamed; Kato, Tatsuya; Togari, Hajime

doi:10.1203/01.pdr.0000061540.81669.2a

Cited by 30 publications

(22 citation statements)

References 29 publications

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“…The indices for cardiac output and stroke volume of the 6w-and 8w-MCT rats were decreased, suggesting the genesis of heart failure in this model. The right ventricular Tei index is used for the assessment of right ventricular dysfunction in patients with pulmonary artery hypertension (21,27,28). The right ventricular Tei indices of the 6w-and 8w-MCT rats were markedly increased, suggesting that the right ventricular function was maintained until the 4th week, but aggravated thereafter.…”

Section: Discussionmentioning

confidence: 99%

Possible Involvement of Mitochondrial Energy-Producing Ability in the Development of Right Ventricular Failure in Monocrotaline-Induced Pulmonary Hypertensive Rats

et al. 2009

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Abstract. The present study was undertaken to explore the possible involvement of alterations in the mitochondrial energy-producing ability in the development of the right ventricular failure in monocrotaline-administered rats. The rats at the 6th week after subcutaneous injection of 60 mg/kg monocrotaline revealed marked myocardial hypertrophy and fibrosis, that is, severe cardiac remodeling. The time-course study on the cardiac hemodynamics of the monocrotalineadministered rat by the cannula and echocardiographic methods showed a reduction in cardiac double product, a decrease in cardiac output index, and an increase in the right ventricular Tei index, suggesting that the right ventricular failure was induced at the 6th week after monocrotaline administration in rats. The mitochondrial oxygen consumption rate of the right ventricular muscle isolated from the monocrotaline-administered animal was decreased, which was associated with a reduction in myocardial high-energy phosphates. Furthermore, the decrease in mitochondrial oxygen consumption rate was inversely related to the increase in the right ventricular Tei index of the monocrotaline-administered rats. These results suggest that impairment of the mitochondrial energy-producing ability is involved in the development of the right ventricular failure in monocrotaline-induced pulmonary hypertensive rats.

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Section: Discussionmentioning

confidence: 99%

Possible Involvement of Mitochondrial Energy-Producing Ability in the Development of Right Ventricular Failure in Monocrotaline-Induced Pulmonary Hypertensive Rats

et al. 2009

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“…In PHT, both systolic and diastolic dysfunction occur; consequently, we used the Tei index, which combines diastolic and systolic parameters, to assess global RV function (26,27,33). The Tei index is a powerful tool with significant prognosis for RV dysfunction in primary PHT (27,34).…”

Section: Discussionmentioning

confidence: 99%

“…It has been used in the assessment of RV dysfunction, especially in PHT (26). In conventional pulsed Doppler, the Tei index derives from both isovolumic contraction and relaxation times (IVCT and IVRT) as well as ejection time of RV outflow and therefore needs to record both tricuspid and pulmonary flow in two different windows.…”

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confidence: 99%

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

Boissière¹,

Gautier²,

Machet³

et al. 2005

American Journal of Physiology-Heart and Circulatory Physiology

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-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 Ϯ 1.6 and 13.2 Ϯ 2.9 ms in hypoxic and monocrotaline PHT groups vs. 28.1 Ϯ 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 ϭ 17.0 Ϯ 1.4) compared with the hypoxic PHT and control groups (11.5 Ϯ 0.7 and 10.2 Ϯ 0.4, respectively). Tei index measured using DTI highlighted global RV dysfunction in the monocrotaline PHT group (1.36 Ϯ 0.24 vs. 0.92 Ϯ 0.05 and 0.86 Ϯ 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-Sm 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 CHRONIC ALVEOLAR HYPOXIA, which often occurs in patients suffering from chronic obstructive pulmonary diseases, secondarily induces a sustained increase in pulmonary artery resistance. The subsequent pulmonary artery hypertension (PHT) leads to right ventricle (RV) pressure overload and hypertrophy (22).Conventional transthoracic echocardiography is widely used to detect PHT in humans and animal models (14, 18). The standard parameters are the RV free wall thickening recorded in time-motion (TM) mode, the presence of mild-systolic notch, and the acceleration time decrease in the pulmonary outflow spectrum recorded in pulsed-Doppler mode. Nevertheless, a more extensive assessment of PHT-induced RV dysfunction remains difficult using conventional echocardiography. Indeed, accuracy of RV systolic and diastolic functions assessment is limited by complex anatomy and geometry of the ventricle.The Tei index, which combines both systolic and diastolic parameters, was suggested to determine global myocardial performance (27). It has been used in the assessment of RV dysfunction, especially in PHT (26). In conventional pulsed Doppler, the Tei index derives from both isovolumic contraction and relaxation times (IVCT and IVRT) as well as ejection time of...

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“…The RV Tei index is used for the assessment of RV dysfunction in patients with PAH. 13,28,29) Thus, we used Tei index to be a marker for cardiac dysfunction. The RV Tei index of the 4w-to 8w-MCT rats was increased, suggesting that normal RV function was maintained until the 4th week, but was aggravated thereafter.…”

Section: Discussionmentioning

confidence: 99%

Alterations in Pharmacological Action of the Right Ventricle of Monocrotaline-Induced Pulmonary Hypertensive Rats

Daicho

Yagi

Takano

et al. 2009

Biological & Pharmaceutical Bulletin

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Pulmonary arterial hypertension (PAH) is a progressive disease caused by a variety of pulmonary and/or cardiac disorders. PAH is commonly characterized by an increase in the pulmonary vascular resistance or in the right ventricular systolic pressure (RVSP). A rise in RVSP induces the right ventricular (RV) hypertrophy, and RV failure, and may eventually lead to premature death. It is well known that a single subcutaneous administration of a pyrrolizidine alkaloid monocrotaline (MCT) to rats causes cardiovascular and pulmonary disorders similar to those in patients with PAH 1,2) including severe RV hypertrophy 3,4) and RV failure. [5][6][7][8] Despite extensive studies, serial events of MCT-induced functional changes in the development and progression of RV failure have not been fully elucidated.The present study was designed to elucidate pathophysiological and pharmacological alterations of the RV function of MCT administered rats. To examine time-matched alterations of the RV function of MCT administered animals, we focused on the time course of study on cardiac function by a noninvasive echocardiography in rats. MATERIALS AND METHODS AnimalsMale Wistar rats (SLC, Hamamatsu, Japan) weighting 190-210 g were used in the present study. Rats were randomly selected to receive a subcutaneous injection of either monocrotaline (MCT, 60 mg/kg) or an equal volume of saline (CON). The animals were conditioned according to Guide for the Care and Use of Laboratory Animals as published by the U.S. National Institutes of Health (NIH Publication No. 85-23, revised 1996). The protocol of this study was approved by the Committee of Animal Use and Welfare of Tokyo University of Pharmacy and Life Sciences.Echocardiography Transthoracic echocardiography was performed on rats according to the method described previously, 9) in which experimental conditions employed, including appropriate anesthesia, were extensively examined. In the present study, rats were evaluated 2, 4, 6, and 8 weeks after administration of either MCT (2w-, 4w-, 6w-, and 8w-MCT rats) or vehicle (2w-, 4w-, 6w-, and 8w-CON rats, respectively).The animals were anesthetized with 40 mg/kg intraperitoneally (i.p.) pentobarbital sodium, and then their hairs on the chest were shaved before examination. Two-dimensional and Doppler imaging were performed by using ProSound 5500 R (Aloka, Tokyo, Japan) with a 10-MHz transducer. The transthoracic echocardiographic probe was placed to obtain long-axis and apical four-chamber views. To evaluate right ventricular (RV) function, cardiac output (CO) and stroke volume (SV) at the pulmonary artery and the RV Tei index were measured. After determination of the pulmonary arterial flow, heart rate (HR), velocity time integral (VTI), and pulmonary arterial diameter (PAD) were measured by the long-axis view. The ratios of CO and SV to body weight (BW) were calculated according to the following equations (CO and SV indices (COI and SVI), respectively) 9,10) : COIϭ(PAD/2) 2 ϫpϫVTIϫHR/BW, SVIϭCO/(HRϫBW). In addition, to characterize the pu...

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Usefulness of a New Doppler Index for Assessing Both Ventricular Functions and Pulmonary Circulation in Newborn Piglet With Hypoxic Pulmonary Hypertension

Cited by 30 publications

References 29 publications

Possible Involvement of Mitochondrial Energy-Producing Ability in the Development of Right Ventricular Failure in Monocrotaline-Induced Pulmonary Hypertensive Rats

Possible Involvement of Mitochondrial Energy-Producing Ability in the Development of Right Ventricular Failure in Monocrotaline-Induced Pulmonary Hypertensive Rats

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

Alterations in Pharmacological Action of the Right Ventricle of Monocrotaline-Induced Pulmonary Hypertensive Rats

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