Application of Proximal Isovelocity Surface Area Method to Determine Prosthetic Mitral Valve Area

Değertekin, Muzaffer; Gençbay, Murat; Başaran, Yelda; Duran, İbrahim; Yılmaz, Hüseyin; Dindar, İsmet; Turan, Fikret

doi:10.1016/s0894-7317(98)70157-9

“…In general, PISA has been found to be more useful for determining regurgitant severity and for quantifying mitral regurgitation than other modalities in various types of mitral regurgitation, including prosthetic valve regurgitation, in adult humans and in children. 10,13,[18][19][20][21][22][23] In fact, because adult humans are similar in size and peak velocity and the velocity time integral is similar from patient to patient, a simpler method of just measuring the radius of the hemicircle at a given Nyquist limit has been advocated in human medicine as one of the best ways of quickly evaluating the severity of mitral regurgitation.…”

Section: Discussionmentioning

confidence: 99%

Regurgitant Fraction Measured by Using the Proximal Isovelocity Surface Area Method in Dogs with Chronic Myxomatous Mitral Valve Disease

Kittleson

¹

,

Brown

²

2003

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Previous studies have demonstrated that regurgitant fraction can be measured by using the proximal isovelocity surface area (PISA) method. For this study, we utilized this Doppler echocardiographic method to estimate the magnitude of mitral regurgitation in dogs with myxomatous mitral valve disease. Seventeen older, small dogs with chronic mitral regurgitation and no to mild myocardial failure were studied. A blinded observer judged the clinical severity of mitral regurgitation to be mild, moderate, or severe by using echocardiographic assessment of left heart size. The regurgitant fraction was calculated by using the PISA method and spectral Doppler echocardiography. The regurgitant fraction was compared to the clinical assessment of severity for each dog and to calculations of left atrial size. Five dogs had clinically mild mitral regurgitation. Four of these dogs had a regurgitant fraction between 22 and 41%, whereas 1 had a regurgitant fraction of 73%. The 3 dogs with clinical evidence of moderate mitral regurgitation had a regurgitant fraction of 46-65%. All 9 dogs with clinically severe mitral regurgitation had a regurgitant fraction greater than 75% (78-88%). The regurgitant fraction was statistically different between each group (P Ͻ .001). A good but curvilinear relationship was found between left atrial size and regurgitant fraction (r 2 ϭ 0.72). In this study, dogs with clinically severe mitral regurgitation consistently had hemodynamically severe regurgitation (regurgitant fraction Ͼ 75%), whereas dogs with clinically mild to moderate disease had lesser degrees of regurgitation. Good correlation was found between regurgitant fraction and left atrial size. We conclude that the major determinant of left atrial size and disease severity in dogs with mitrial regurgitation is the degree of mitral regurgitation.Key words: Congestive heart failure; Doppler echocardiography; Heart disease B ased on the measurement of the left ventricular endsystolic diameter, myocardial function seems to be normal or only mildly compromised in most small and medium-sized dogs with chronic mitral regurgitation secondary to myxomatous mitral valve disease, even when heart failure is present.1,2 Therefore, it is reasonable to surmise that the blood volume ejected into the left atrium in systole (ie, the amount of mitral regurgitation) is the major determinant of the degree of left heart volume overload in these dogs and is the primary variable that produces heart failure because it is the only other primary variable, other than myocardial function, that determines the degree of compensatory volume overload in this disease. Although regurgitant fraction has been measured previously in dogs with myxomatous mitral valve disease, the relationship between the severity of the mitral regurgitation and clinical status has not been clearly delineated. 3The present study was designed to prospectively measure the percentage of stroke volume ejected into the left atrium in systole (ie, the regurgitant fraction) in small to mediumsized dogs...

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“…In general, PISA has been found to be more useful for determining regurgitant severity and for quantifying mitral regurgitation than other modalities in various types of mitral regurgitation, including prosthetic valve regurgitation, in adult humans and in children. 10,13,[18][19][20][21][22][23] In fact, because adult humans are similar in size and peak velocity and the velocity time integral is similar from patient to patient, a simpler method of just measuring the radius of the hemicircle at a given Nyquist limit has been advocated in human medicine as one of the best ways of quickly evaluating the severity of mitral regurgitation. 24 A small number of studies have examined the PISA technique in experimental dogs.…”

Section: Discussionmentioning

confidence: 99%

Regurgitant Fraction Measured by Using the Proximal Isovelocity Surface Area Method in Dogs with Chronic Myxomatous Mitral Valve Disease

Kittleson

¹

,

Brown

²

2003

Veterinary Internal Medicne

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Previous studies have demonstrated that regurgitant fraction can be measured by using the proximal isovelocity surface area (PISA) method. For this study, we utilized this Doppler echocardiographic method to estimate the magnitude of mitral regurgitation in dogs with myxomatous mitral valve disease. Seventeen older, small dogs with chronic mitral regurgitation and no to mild myocardial failure were studied. A blinded observer judged the clinical severity of mitral regurgitation to be mild, moderate, or severe by using echocardiographic assessment of left heart size. The regurgitant fraction was calculated by using the PISA method and spectral Doppler echocardiography. The regurgitant fraction was compared to the clinical assessment of severity for each dog and to calculations of left atrial size. Five dogs had clinically mild mitral regurgitation. Four of these dogs had a regurgitant fraction between 22 and 41%, whereas 1 had a regurgitant fraction of 73%. The 3 dogs with clinical evidence of moderate mitral regurgitation had a regurgitant fraction of 46-65%. All 9 dogs with clinically severe mitral regurgitation had a regurgitant fraction greater than 75% (78-88%). The regurgitant fraction was statistically different between each group (P < .001). A good but curvilinear relationship was found between left atrial size and regurgitant fraction (r2 = 0.72). In this study, dogs with clinically severe mitral regurgitation consistently had hemodynamically severe regurgitation (regurgitant fraction > 75%), whereas dogs with clinically mild to moderate disease had lesser degrees of regurgitation. Good correlation was found between regurgitant fraction and left atrial size. We conclude that the major determinant of left atrial size and disease severity in dogs with mitrial regurgitation is the degree of mitral regurgitation.

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“…24 The proximal isovelocity surface area method based on the CE can only be applied using the transesophageal approach and is not practical. 25,26 Colour flow imaging provides good qualitative or semi-quantitative information and together with continuous wave Doppler acts as adjuvant to the clinical suspicion of obstruction. The previous studies have also shown that the valve area calculated in vivo with flow equations is less than AOA.…”

Section: Mitral Valve Area By Pressure Half-timementioning

confidence: 99%

Doppler Echocardiographic Assessment of TTK Chitra Prosthetic Heart Valve in the Mitral Position

2008

European Journal of Echocardiography

1

0

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Aims TTK Chitra heart valve prosthesis (CHVP), a tilting disc mechanical heart valve of low cost and proven efficacy, has been in use for the last 15 years. Although various studies substantiating its longterm safety and efficacy are available, no study had assessed its echocardiographic characteristics. The purpose of this study was to determine the normal Doppler parameters of CHVP in the mitral position and to assess whether derivation of mitral valve area (MVA) using the continuity equation (CE) and more commonly used pressure half-time (PHT) method is comparable in the functional assessment of this tilting disc mitral prosthesis. Methods and results Doppler echocardiography was performed in 40 consecutive patients with CHVP in the mitral position. All patients were clinically stable, without evidence of prosthetic valve dysfunction such as significant obstruction or regurgitation, endocarditis, left ventricular dysfunction (ejection fraction ,40%), or significant aortic regurgitation. Valve sizes studied included 25, 27, and 29 mm. Mitral valve area was derived both by the PHT method and by the CE, using the stroke volume measured in the ventricular outflow tract divided by the time-velocity integral of CHVP jet. The peak Doppler gradient ranged from 5 to 21 (mean 11.0) mmHg, and the mean gradient ranged from 1.7 to 9.2 (mean 4.1) mmHg. Mean gradient negatively correlated with an increase in the actual orifice area (AOA) derived from the valve orifice diameter given by the manufacturer (r ¼ 20.45, P ¼ 0.004). Mitral valve area calculated by both PHT and CE increased significantly with an increase in the AOA (r ¼ 0.42, P ¼ 0.007 and r ¼ 0.32, P ¼ 0.046, respectively). Mitral valve area by the CE averaged 1.55 + 0.36 cm 2 (range 0.85 cm 2 for a 25 mm valve to 2.41 cm 2 for a 29 mm valve) and was smaller than by PHT (mean 2.04 + 0.41 cm 2 , range 1.40-3.14 cm 2 ; P ¼ 0.0001; t-test), irrespective of whether PHT is less than or .110 ms. Conclusion The Doppler parameters obtained with CHVP in the mitral position are comparable with those obtained with the different prosthetic valves in common use. In the selected group of patients with CHVP, assessment of MVA by the PHT method is comparable with that by the CE. Areas by both methods were smaller than the AOA provided by the manufacturer, as seen in other similar design valves.

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Application of Proximal Isovelocity Surface Area Method to Determine Prosthetic Mitral Valve Area

Cited by 8 publications

References 23 publications

Regurgitant Fraction Measured by Using the Proximal Isovelocity Surface Area Method in Dogs with Chronic Myxomatous Mitral Valve Disease

Regurgitant Fraction Measured by Using the Proximal Isovelocity Surface Area Method in Dogs with Chronic Myxomatous Mitral Valve Disease

Regurgitant Fraction Measured by Using the Proximal Isovelocity Surface Area Method in Dogs with Chronic Myxomatous Mitral Valve Disease

Doppler Echocardiographic Assessment of TTK Chitra Prosthetic Heart Valve in the Mitral Position

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