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Determinants of transmitral inflow pattern 10-14 days after acute myocardial infarction
A E Aubert1, I K Jang, T Brzostek
1University Hospital Gasthuisberg, Leuven, Belgium.
Insights
Recombinant tissue plasminogen activator (rTPA) did not alter diastolic function post-myocardial infarction. However, both rTPA and placebo groups showed impaired diastolic function compared to controls, influenced by infarct size and other patient factors.
Area of Science:
- Cardiology
- Medical Imaging
- Pharmacology
Background:
- Thrombolytic therapy, such as recombinant tissue plasminogen activator (rTPA), is used to treat acute myocardial infarction (AMI).
- AMI can impair left ventricular function, including diastolic function.
- Pulsed Doppler is a non-invasive technique to assess cardiac function.
Purpose of the Study:
- To evaluate the effect of rTPA on left ventricular diastolic function after AMI using pulsed Doppler.
- To compare diastolic function in patients treated with rTPA, placebo, and healthy controls.
- To investigate the relationship between infarct size and diastolic function parameters.
Main Methods:
- A study involving 104 patients with AMI (48 placebo, 56 rTPA) and 36 age-matched controls.
- Pulsed Doppler was used to measure key diastolic function parameters: early peak diastolic flow velocity, atrial contraction peak, atrial:early ratio, deceleration time, and half-filling fraction.
- Comparison of Doppler parameters between treatment groups, controls, and subgroups based on infarct size.
Main Results:
- No significant difference in Doppler parameters was observed between the rTPA and placebo groups.
- Both AMI treatment groups exhibited significant diastolic dysfunction compared to controls, evidenced by altered early peak velocity, atrial:early ratio, and half-filling fraction.
- Patients with large infarcts showed a depressed atrial peak velocity. Multivariate analysis identified end-diastolic pressure, age, end-systolic volume, and wall motion as predictors of diastolic function.
Conclusions:
- rTPA administration did not significantly alter left ventricular diastolic function parameters in patients with AMI compared to placebo.
- Patients with AMI, regardless of rTPA treatment, exhibit impaired diastolic function compared to healthy individuals.
- Infarct size and hemodynamic/echocardiographic parameters are key determinants of diastolic dysfunction severity after AMI.
Aim:
The administration of thrombolytic therapy after an acute myocardial infarction can reduce the size of the infarct and improve left ventricular function. We used pulsed Doppler to assess left ventricular diastolic function after an acute myocardial infarction in patients treated with recombinant tissue plasminogen activator (rTPA).
Patients And Methods:
We studied 104 patients after an acute myocardial infarction, 48 treated with a placebo and 56 with rTPA. They were compared with 36 age-matched controls. The Doppler parameters measured included the early peak in diastolic flow velocity, the peak during atrial contraction, the atrial: early ratio, mean deceleration, deceleration time, and half-filling fraction. Doppler parameters for large and small infarct sizes were compared.
Results:
The Doppler parameters did not differ between treatment groups. Compared with the normal controls, significant differences were observed in both treatment groups for the early peak (placebo P < 0.05; rTPA P < 0.001), the atrial: early ratio (placebo P < 0.05; rTPA P < 0.01), and the half-filling fraction (P < 0.001 for both). In patients with large infarcts, the atrial peak was depressed (P = 0.008). Multivariate analysis showed that end-diastolic pressure, age, end-systolic volume, and regional wall motion parameters were major predictors of Doppler parameters.