Left Ventricular Inferior Myocardial Infarction Research Articles

Right Atrial and Right Ventricular Function Assessed by Speckle Tracking in Patients with Inferior Myocardial Infarction

Background: In patients with inferior myocardial infarction (MI), involvement of the right chambers has a prognostic impact. The objective of this study was to evaluate the influence of left ventricular (LV) inferior wall MI in the right atrial (RA), and right ventricular (RV) longitudinal strain (LS) by 2D speckle tracking echocardiography (STE). Methods: 60 consecutive patients who underwent myocardial perfusion (MP) gated SPECT for chest pain were included. We studied 30 patients with LV inferior MI and 30 control subjects with normal MP. RV ejection fraction was measured by 3D transthoracic echocardiography, RV-free wall LS and RA reservoir, contraction, and conduit phases strain were analyzed by 2D speckle tracking echocardiography (STE). Results: The median age in the LV inferior MI was 65 (54–70) years, 27% had a transmural myocardial infarction and 47% had residual myocardial ischemia, most of them, mild (36.7%). RV-free wall LS (–26.1 vs –30.3, p < 0.01), RA LS-reservoir phase (31.5 vs 56.2, p < 0.01), and RA-conduit phase LS (12.5 vs 35, p = 0.01) were significantly lower in the LV inferior MI patients compared to control subjects. In a logistic regression model, the MI of the LV reduced the 3D ejection fraction of both ventricles, mitral regurgitation, and pulmonary hypertension were associated with a decrease in RV LS and RA LS. Conclusions: This study shows that RV free wall LS, RA peak strain (reservoir phase), and RA conduit phase strain were significantly lower in patients with LV inferior MI vs control individuals. Subclinical extension to the RV in the inferior MI of the LV and its role in the longitudinal strain of RA could be determined using speckle tracking echocardiography.

Fatal cerebral and cardiac infarction due to embolism of a mobile thrombus from aorta sinotubular junction atheroma in a 40-year-old female

Strokes in young adults present a challenging problem in terms of care and social impact. Most of cases in this cohort are classified as strokes of uncertain etiology. Application of multimodality diagnostic approach could help in the estimation of risk factors and underlying mechanisms. Simultaneous acute cardio-cerebral infarction is a rare manifestation, especially in young individuals. Large artery atherosclerosis should be excluded as a potential cause. Transesophageal echocardiography plays an important role in the diagnostic algorithm. The current article presents a clinical case of a fatal acute cardio-cerebral infarction in a 40-year old female without previous cardiovascular diseases and negative family history. Transesophageal echocardiography identified a large mobile thrombus at the sinotubular junction of ascending aorta. Transthoracic echocardiography revealed regional akinesia of the inferior wall, despite normal electrocardiogram. The autopsy findings confirmed co-occurrence of thromboembolic stroke in the right middle cerebral artery area and left ventricular inferior myocardial infarction due to thrombosis of the right coronary artery. This case documents an exceedingly rare phenomenon in this cohort of a cardio-cerebral thromboembolism due to single atherosclerotic plaque destabilization.

Assessment of the right ventricular systolic function after acute right ventricular myocardial infarction in association with left ventricular inferior myocardial infarction by two-dimensional speckle tracking echocardiography

Objective To assess right ventricular (RV) systolic function in patients with acute right ventricular myocardial infarction (RVMI) in association with left ventricular inferior myocardial infarction (INFMI) by applying 2-dimensional (2D) speckle tracking imaging (STI) longitudinal strain (LS) and strain rate (LSr) parameters. Methods Seventeen consecutive patients diagnosed with INFMI in association with RVMI were included in our study, 21 INFMI patients without RVMI were also included to match the RVMI group. RVMI group and INFMI group were called acute myocardial infarction (AMI) group, all of them were diagnosed AMI the first time. Twenty-four chest pain patients admitted consecutively at the same time but with negative results in the selective coronary angiography were served as blank control. Echocardiography were performed within 48 hours. The RVLS parameters, which include LS and LSr, were then analyzed offline. Results The RV global LS (RVGLS), the LS of the basal and mid segments of the free wall and septum, the LSr of the basal and mid segments of the free wall were lower than control group in the AMI group (P<0.05). Compared to INFMI group, the RVGLS, the LS of the mid and apical segments of the free wall and the LSr of the mid segments of the septum were lower in the RVMI group (P<0.05). In the single parameter mode of ROC curve analysis, the diagnosis efficiency of RV free wall LS (RVFWLS) and RVGLS were higher than other parameters. The cut-off value of RVFWLS and RVGLS were -18.26% and -16.27% respectively (sensitivity were 100% and 100%, respectively, specificity were 65.5% and 72.4%, respectively). Conclusions The 2D-STI RVLS parameters precisely reflect the impaired RV systolic function in the INFMI and RVMI patients, the RV global systolic function are even worse when RVMI involved, mainly for the RV free wall. RVLS parameters are good predictors of RVMI which could provide more references for the early diagnosis and functional evaluation of RV in acute INFMI patients with RVMI. Key words: Echocardiography; Myocardial infarction; Ventricular function, right; Speckle tracking imaging

Differentiation of pseudodyskinesis of inferior left ventricular wall from inferior myocardial infarction by assessment of regional myocardial strain using two-dimensional speckle tracking echocardiography

Purpose To differentiate pseudodyskinesis (PD) of the inferior left ventricular (LV) wall from inferior myocardial infarction (IMI) noninvasively, we performed focal site evaluation using two-dimensional speckle tracking transthoracic echocardiography (TTE). Materials and methods Speckle tracking TTE was carried out in 57 patients, with 19 subjects in each of three groups (Group A, suspected PD; Group B, LV IMI; and Group C, controls). Inferior wall PD was defined as follows: compression of the inferior LV wall by the diaphragm in the LV short axis view with a normal electrocardiogram and no evidence of previous ischemic events. Results Respective values in Groups A–C for LV ejection fraction (EF) were 63.6 ± 4.2%, 52.3 ± 7.6%, and 61.5 ± 3.8%, for inferior wall speckle tracking focal site evaluation peak radial strain of 30.0 ± 14.3%, 7.5 ± 7.1%, and 42.1 ± 22.9%, for peak circumferential strain of 23.1 ± 6.0%, 16.8 ± 8.4%, and 22.7 ± 7.1%, and for longitudinal strain in the mid-inferior wall of 18.4 ± 3.4%, 11.4 ± 4.0% and 15.8 ± 5.9%. LVEF values were significantly lower in Group B than Groups A and C (P < 0.001), as were those of radial, circumferential, and longitudinal strains (P < 0.05). In receiver-operating characteristic analysis the optimal cut-off values with corresponding sensitivities and specificities for differentiation of PD from IMI were > 19% with 84.2% and 94.7% for radial, > 15% with 89.4% and 52.6% for circumferential, and > 15% with 73.6% and 100% for longitudinal strain, respectively. Conclusions Determination of regional strain from speckle tracking TTE, especially radial and longitudinal strains, can provide focal and quantitative noninvasive evaluation for distinguishing PD of the inferior wall from IMI.

ST elevations in leads V 1 to V 5 may be caused by right coronary artery occlusion and acute right ventricular infarction

In 5 of 69 patients (7%) undergoing intracoronary or intravenous streptokinase treatment, the ST-segment elevations in leads V 1 to V 5 were caused by occlusion of the right rather than the left anterior descending coronary artery and by myocardial infarction (MI) of the right ventricular (RV) wall rather than the anterior left ventricular (LV) wall or the ventricular septum. RV involvement was documented by technetium pyrophosphate uptake, hypokinesia, dilatation and depressed RV ejection fraction. The left anterior descending artery was patent and the anterior LV wall had normal thallium-201 uptake, no technetium uptake and normal wall motion. ST-segment elevation was highest in lead V 1 or V 2 and decreased toward lead V 5; in patients with anterior LV MI, the ST-segment elevations are usually lowest in lead V 1 and increase toward the V 5 lead. In contrast to anterior LV infarcts, the R waves in leads V 1 to V 5 did not decrease and Q waves did not evolve with progression of the MI. The ST-segment elevations in leads V 1 to V 5 in our patients were associated with small or absent ST-segment elevations in leads, II, III and aVF, suggesting that in other cases of RV infarction, the appearance of ST-segment elevations in leads V 1 to V 5 is blocked by the dominant electrical forces of the LV inferior MI. This suggestion was confirmed in a canine model. Recognition of the presence of RV infarction may be therapeutically important.