Estimation of Left Ventricular End Diastolic Pressure by Tissue Doppler Imaging in Patients with Acute Myocardial Infarction

Abstract

Objective: To evaluate sensitivity and specificity of E / Ea > 10 for prediction of LVEDP > 15 mmHg in patients with coronary artery disease undergoing left heart catheterization.
Materials and Methods: Sixty patients of acute transmural myocardial infarction at Jinnah Hospital Lahore were enrolled in study from December 2008 to December 2009. Patients with sinus rhythm were included in the study. Patients with val-vular heart disease, complete right/left bundle branch block, Pacemaker dependence, Atrial fibrillation and Post mitral valve replacement were excluded. All patients were examined by performing transthoracic Doppler echocardiography. The trans-mitral LV filling signal was traced manually and the following variables were obtained: peak early (E) and late (A) trans-mitral velocities, and E/A ratio. Tissue – Doppler derived indices were recorded at the lateral mitral annulus. These indices included systolic velocities (S'), early diastolic (Ea) velocities and late diastolic (Aa) velocities. Finally, the dimensionless index of E/Ea was calculated. All were averaged from at least three beats. Cardiac cathetrization was performed via trans-femoral / trasradial route using six French (6F) sheaths. Left ventricular diastolic pressure was directly measured by fluid filled pigtail catheter attached to a pressure transducer.
Results: Mean age of the study population was 56.8 ± 12.7 years. There were 47 (78.3%) males and 13 (21.7%) females. Diabetes mellitus was present in 12(20%), hypertension in 32 (53.3%), smoking in 35 (58.3%), dyslipidemia in 24 (40%). Anterior wall myocardial infarction occurred in 44 (73.3%) and inferior wall MI in 16 (26.7%). Grade I diastolic dysfunction was present in 22 (36.7%), Grade II in 31 (51.7%) and Grade III in 7 (11.7%) patients. E/E < 10 was observed in 31 (51.7%), 11 – 15 in 20 (33.3%) and > 15 in 9 (15%). Overall 21 patients were true positive, 6 were false positive, 25 were true nega-tive and 8 were false negative. By applying 2 × 2 table sensitivity was 77.7%, specificity was 80.6%, positive predictive value was 77.7% and negative predictive value was 75.7%.
Conclusion: Doppler echocardiography provided major insights into the pathophysiology of diastolic LV dysfunction. E/Ea ratio is a reasonably good index for predicting elevated left ventricular filling pressure. E/Ea significantly correlated with LVEDP in the population with high prevalence of coronary artery disease. This method is the standard in measuring pres-sures in most clinical settings.
Key Words: Acute myocardial infarction; Coronary artery disease; Doppler echocardiography; Tissue Doppler imaging; Diastolic dysfunction.