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ГоловнаРізне → Клапанна кардіоміопатія: ультразвукові методи у виявленні, оцінці прогнозу і виборі лікувальної тактики (автореферат) - Реферат

Клапанна кардіоміопатія: ультразвукові методи у виявленні, оцінці прогнозу і виборі лікувальної тактики (автореферат) - Реферат

The temporal response of left ventricular (LV) dimensions and contractility after surgical treatment of severe asymptomatic mitral regurgitation (MR) in comparison with other echocardiographic indices has been investigated. The only preoperative predictor of the late LV dysfunction is a TDI mitral annular systolic velocity (Sm) measured by tissue Doppler imaging (TDI) method: in a group with late LV dysfunction the value of Sm was significantly lower preoperatively (9.41.5 cm/s) than in patients with normal late LV function (14.81.2 cm/s; p<0.01). Preoperative Sm value correlates well with an extent of LV EDD reduction in early postoperative period (r = +0.52) and with LVEF in late period (r = +0.44). It was concluded that Sm value less than 10 cm/s reflects the latent and potentially irreversible changes in LV myocardium. The surgical correction of MR to be performed in time it is useful to follow up the Sm velocity during the disease progression.

It was obtained strong evidences that in severe AR like in MR the decreasing of Sm velocity and prolonging of systolic time TDI indices PCTm and СТm and their ratio PCTm/СТm are reliable predictors of irreversible changes in LV despite of preserved EF and absence of excessive LV dilation. The Sm velocity less than 9 cm/s could reliably predict the late LV dysfunction after valve replacement.

To investigate the ability of Echo to estimate the probability (high, mean and low) of reconstructive surgery in MR 84 consecutive cases of surgical treatment of pure MR have been analyzed. Reconstructive procedure as a primary surgery has been performed in 40% patients. Most often the valve repair was performed in functional MR (83%), less often in organic MR with leaflets hypermobility (42%), mostly with flail or prolapsed medial scallop of the posterior leaflet. In organic MR without leaflets hypermobility valve repairing procedure has been done just in 22%. Preoperative assessment of valve repair probability appeared quite accurate: it has been performed in 21 (72%) from 29 patients with high probability, in 11 (48%) from 23 patients with mean probability and in 2 (6%) from 32 patients with low probability. We concluded that echocardiographic examination performed by a special protocol allows the possibility prediction of reconstructive surgery in MR and accurate cases allocation to the different probability groups.

It was evaluated the LV hypertrophy regression and its systolic and diastolic function dynamics after valve replacement in 28 patients with AS and low preoperative EF in relation to the initial diastolic dysfunction type. All patients with severe AS and low LV EF showed LV diastolic dysfunction and 39% of them had irreversible restrictive pattern. Valve replacement does not lead to LV hypertrophy regression and functional indeces improvement in late postoperative term if diastolic function was deeply impaired preoperatively. Significant positive changes develope in groups with less severe preoperative diastolic dysfunction.

In severe AS it was revealed by the TDI method significant RV diastolic disorders manifesting with Am velocity increasing, low Em/Am ratio, pronging DTEm and IVRTm. We showed that his changed are related to extent of LV hypertrophy and AS severity.

The complex of noninvasive ultrasound parameters is proposed for pulmonary hypertension prediction in patients with AS. It includes: restrictive transmitral filling (Е/А>2 і DTЕ<120 ms); restrictive RV filling (Е/А>1.6 і DTЕ<150 ms); MR more than 2+ in combination with LA enlargement (>48 mm).

It was investigated which of ТDІ RV wall kinetics parameters properly reflect the pulmonary hypertension in mitral stenosis. In a subgroup with pulmonary hypertension the mean IVRTm was 767,9 ms and in a subgroup with normal pressure – 326,4 ms (р<0,01). A cut-off 40 ms detected patients with pulmonary hypertension with a sensitivity 87% and a specificity 80%. No significant correlation was found of RV amplitude TDI indices and tricuspid valve gradient (TVG). However, IVRTm correlated well with TVG: r=0,88 (p<0,05). We concluded that IVRTm could be used as an alternative parameter of pulmonary hypertension level in difficult to scan patients or in cases when it is not possible to measure a TVG.

The precise understanding of mechanisms leading to development of valvular cardiomyopathy demands the evaluation of coronary flow (CF) velocity changes. Investigation of CF parameters in LAD using transesophageal (TEE) Doppler showed that in AS the diastolic phase is enhanced and systolic phase diminished. In MS the flow is increased in both phases proportionally to RV pressure increasing and mitral orifice area decreasing. After aortic valve replacement with normal prosthetic function all CF parameters practically normalized. When prosthetic dysfunction occured the CF parameters reversed to levels observed in preoperative status.

The comparison of preoperative diagnostic conclusions and intraoperative picture in patients with IE showed that full Echo-examination reliably reveals the changes and unexpected findings (20.8%) were not significant and did not change the course of surgery. Despite of improvement of ultrasound visualization achieved in recent decade the transthoracic examination still could not compete with TEE mode. To avoid the delay in proper recognition of important complication (abscesses and pseudoaneurysms) TEE should be performed early to all IE patients.

The progression of CHF in patients after successful valve replacement needs to differentiate the valvular cardiomyopathy and prosthetic valve dysfunction. The analysis of our data shows that this complicated task could be solved by radiological methods including fluoroscopy, transthoracic and transesophageal echography. The only method allowing the precise recognition of dysfunction mechanism and proving the treatment choise in majority of cases is transesophageal echocardiography.

Key words: valvular heart disease,myocardium, diastolic function, valvular cardiomyopathy, pulmonary hypertension, heart valve prosthesis, transesophageal echocardiography, pulsed wave tissue Doppler imaging, fluoroscopy.











































Аортальний клапан

Аортальна недостатність

Аортальний стеноз

Дилятаційна кардіоміопатія

Задня стінка

Кінцево-діастолічний об'єм

Кінцево-діастолічний розмір

Кінцево-систолічний об'єм

Кінцево-систолічний розмір

Легенева артерія

Ліва коронарна артерія

Ліве передсердя

Лівий шлуночок


Мітральний клапан

Мітральна недостатність

Міжпередсердна перегородка

Мітральний стеноз

Міжшлуночкова перегородка

Недостовірне кількісне значення або відмінність величин

Праве передсердя

Правий шлуночок

Тканинна імпульсно-хвильова допплерографія

Тристулковий клапан

Тристулкова недостатність

Фракція викиду

Хронічна недостатність кровообігу

Пізня (передсердна) діастолічна швидкість руху міокарда

Період скорочення

Період скорочення міокарда (тривалість хвилі Sm)

Час сповільнення раннього діастолічного потоку

Рання діастолічна швидкість руху міокарда

Період ізоволюметричного розслаблення

Період ізоволюметричного розслаблення стінки шлуночка

Міокардіальний преконтракційний час

Пікова систолічна швидкість руху міокарда

Діастолічна швидкість потоку

Швидкість розповсюдження діастолічного потоку у лівому шлуночку

Cистолічна швидкість потоку

Діастолічний швидкісно-часовий інтеграл потоку

Систолічний швидкісно-часовий інтеграл потоку