Abstract

Introduction

Materials & Methods

Results

Discussion & Conclusion

References

Discussion
Board

The study population consisted of 71 symptomatic patients with DC and ejection fraction < 40%. The control population consisted of 30 normal subjects who were included if their age was within the same range as that of patients with DC. All control subjects had normal ejection fraction and no wall motion abnormalities as assessed by echocardiography. All participants gave informed consent before this study began.

Clinical status of patients with DC was assessed according to the New York Heart Association (NYHA) classification. Doppler echocardiography was performed in all patients at the time of symptom classification. The six-minute walk test was performed to assess exercise capacity as described by Guyatt et al. (4).

Complete M-mode, B-mode echocardiography and Doppler ultrasound examinations were performed with a commercially available system operating a 2.5 MHz transducer. Measurements of LV end-diastolic and end-systolic volumes were made using the biplane area-length method. Ejection fraction was calculated with the standard formula. LV myocardial mass was derived with corrected "ASE-cube" formula. Indices of diastolic and systolic sphericity were calculated as described by Mitchel and Pfeffer (5). LV end-systolic wall stress was calculated with the use of ellipsoidal model.

Pulsed Doppler studies were performed by using apical windows. Recordings of mitral inflow velocity were made from a four-chamber view with the sample volume positioned adjacent to the tip of mitral leaflets in diastole. The following Doppler-derived parameters were calculated: peak velocity of early filling (PE), peak velocity of atrial filling (PA), ratio of early wave to atrial wave peak velocity (PE/PA ratio), and deceleration time of early filling. Isovolumic relaxation time was calculated as the interval between the beginning of the aortic valve closure signal and mitral valve opening signal in the Doppler spectrum. All measurements were made in at least five cardiac cycles and analyzed off-line by two independent observers. The data were averaged. In this study, the pattern of LV filling was considered restrictive if the PE/PA ratio was > or = 1 and deceleration time of early filling was < or = 140 ms. Mitral regurgitation was semiquantitatively assessed as none, mild, moderate or severe, depending on the maximal Doppler jet area seen from multiple orthogonal views.

All values were expressed as mean ± standard deviation. Statistical tests for unpaired data were used to compare the studied groups. A p value < 0.05 was considered significant.

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