Right ventricular echocardiographic parameters for prediction of proximal right coronary artery lesion in patients with inferior wall myocardial infarction

Background: Classifying the location of an occlusion in the culprit artery during ST-elevation myocardial infarction is important for risk stratification to optimize treatment

Methods: The study included 76 patients after their first episode of acute inferior myocardial infarction with significant RCA lesion [43 patients with proximal RCA stenosis and 33 patients with distal RCA stenosis]. Full echocardiographic examination was done before revascularization, including RV dimension, tricuspid annular plane systolic excursion, and tissue Doppler imaging of RV free wall at the level of the tricuspid annulus and recording the following variables: peak systolic velocity [Sm], peak early diastolic velocity, peak late diastolic velocity, ejection time [ET], isovolumetric relaxation time [IVRT], isovolumetric contraction time [IVCT], and myocardial performance index [MPI], which was calculated as [MPI=IVRT + IVCT/ET]

Results: Patients with proximal RCA showed significantly lower Sm [10.44 +/- 2.61 cm/s vs. 12.11 +/- 2.94 cm/s, p=0.013] and shorter ET [224.18 +/- 49.96 ms vs. 280.90 +/- 46.12 ms, p=0.001]. While IVRT, IVCT, and MPI were significantly higher [95.25 +/- 19.22 ms vs. 68.48 +/- 12.77 ms, p=0.001; 81.62 +/- 23.59 ms vs. 60.90 +/- 17.38 ms, p=0.001; and 0.82 +/- 0.222 vs. 0.47 +/- 0.10, p=0.001, respectively] when compared with patients with distal RCA stenosis. Multiple regression analysis including [tricuspid annular plane systolic excursion, Sm, and MPI] showed that the most independent predictors for proximal RCA lesions were MPI [p=0.0001]. The receiver operator characteristic curve for MPI showed areas under the curve of 97% and a confidence interval of 93%. A cut-off value of 0.58 for MPI had a sensitivity of 95% and specificity of 97% for the diagnosis proximal RCA

Conclusions: The most independent predictors for proximal RCA lesion is MPI

Validity of the dispersion of myocardial velocities in differentiation between ischemic and dilated cardiomyopathy

Differentiation between ischemic and non ischemic cause for left ventricular dysfunction has important therapeutic implication in patients with chronic heart failure. Tissue Doppler imaging [TDI] has provided an objective means to quantify global and regional left ventricular [LV] function with improved accuracy and high reproducibility. The present study aimed to use tissue Doppler imaging of the left ventricle for differentiation between ischemic and dilated cardiomyopathy. A total of 40 subjects were included in this study, 15 patients with ischemic cardiomyapathy [1CM], 15 patients with dilated cardiomyapathy [DCM] and 10 healthy subjects as a control group. All studied subjects underwent 12 lead electrocardiogram transthoracic echocardiographic examination and TDI. The following regional parameters were measured in the four basal LV myocardial segments [lateral, septal, anterior and inferior walls]: myocardial systolic [Sm], early diastolic [Em] and late diastolic [Am] velocities, with calculation of dispersion index of each TDI velocity. Both Sm and Em were significantly lower in patients group than in control group [P<0.05]. The mean dispersion index of Sm in control group was [8%+4%], in ICM group [28%+8.1%] and [14%+7.1%] in DCM group, the Sm dispersion index was higher in patients than in the control group and in 1CM group compared to DCM group [P=0.01]. The mean dispersion index of Em in control group was [14%+9%], in ICM group [31%+11.6%] and [19%+4.4%] in DCM group, the Em dispersion index was higher in ICM group in comparison to control group or DCM groups [P=0.001]. The mean dispersion index of Am in control group was [5%+3%]. in ICM group [28%+11.8%] and [19%+9.6%] in DCM group, the Am dispersion index was higher in both patients groups in comparison to control group [P=0.0001]. Receiver operating characteristic [ROC] analysis showed that Sm dispersion index cut off value of [14%] detected patients with ICM with a sensitivity [73%] and a specificity of [90%] while Em dispersion index cut off value of [22%] could detect ICM patients with a sensitivity [80%] and a specificity [90%]. Both systolic [Sm] and Early diastolic velocity [Em] and dispersion of myocardial velocities[Sm, Em and Am] measured by TDI can help for differentiation between ischemic and dilated cardiomyopathy

Is left atrial size related to left ventricular hypertrophy in hypertensives?

The present study was specifically designed to identify the effects of systemic arterial hypertension on the left ventricular and left atrial function analyzed by 2D and M-mode echocardiographic images. The study included two groups: Patient group included 30 hypertensive patients with age ranging from 35-70 years [51.5 +/- 10.4]; 11 males [36.7%] and 19 females [63.3%], were subjected to echocardiographic study including 2-dimensional and M-mode. Control group included 15 healthy volunteers with age ranging 35-70 years [51.2 +/- 9.75]; 7 males [46.7%] and 8 females [53.3%]. Statistically, there was no significant difference as regard the age. All patients in the study were subjected to full history taking with special emphasis on valvular heart diseases, congenital heart diseases, ischemic heart disease, medical therapy; especially antiarrhythmic drugs, thorough clinical examination with special emphasis on pulse rate, rhythm, systolic and diastolic blood pressure excluding patients on congestive heart failure, standard 12-lead ECG and echocardiographic examination including 2D and M-mode imaging. The study showed systemic arterial hypertension lead to impairment of left ventricular diastolic function due to increased after load but also the changes of left ventricular geometry and structure producing left ventricular hypertrophy. Also, the left atrium involved in this process by structural abnormalities of the left atrial chamber as regarding by the echo imaging. Individual with systolic arterial hypertension had; 1-ECG finding of LVH. 2-Echoparameters showed increased LAD, LAV, IVS, PWT, RWT, LVM and diastolic dysfunction. 3-Hypertension patients may have LVH or not which may be due to recent incidence or lower level of blood pressure. Hypertension patients without LVH did not show increase in LAD and LAV. 4-Left ventricular hypertrophy could be divided into concentric or eccentric LVH according to present or absence of increase RWT. However LA size and volume were similar in patients with concentric and eccentric LVH. There were positive correlation between LAD and degree of LVH represented by LVM and RWT also LAD positively correlate with LV internal dimension and DT and negatively correlate with E/A ratio