Occlusion Of Proximal Right Coronary Artery Research Articles

TAPSE, Tissue Doppler Systolic annular velocity(S’) and myocardial performance Index (MPI) as a predictor of proximal RCA occlusion in acute inferior wall myocardial ST elevation infarction

TAPSE, Tissue Doppler Systolic annular velocity(S’) and myocardial performance Index (MPI) as a predictor of proximal RCA occlusion in acute inferior wall myocardial ST elevation infarction

A case report: anteroseptal ST elevation due to acute isolated right ventricular infarction

BackgroundElectrocardiogram (ECG) is the first diagnostic tool physicians use in diagnosing acute myocardial infarction (MI). In this case report, we present a case where the initial ECG diagnosis was that of an acute anteroseptal MI but emergency coronary angiography showed that the infarct-related artery was a small non-dominant right coronary artery (RCA) instead of the anticipated left anterior descending artery (LAD). Isolated right ventricular (RV) infarction from a non-dominant RCA is rarely seen in clinical practice, and it may exhibit ECG changes that can be confused with an acute anteroseptal MI. It is important to appreciate the subtle differences in the ECG changes that occur in either of these two types of MI for appropriate diagnosis and treatment.Case presentationA 49-year-old non-smoking male with prior coronary stent implantation in LAD presented with acute chest pain and his pre-hospital ECG indicated an anteroseptal STEMI possibly due to stent thrombosis, but an emergency angiogram showed patent LAD and Circumflex arteries. There was however thrombotic occlusion of the right, non-dominant coronary artery, which was revascularized with a drug-eluting stent. The patient’s chest pain and ST elevations resolved, and subsequent echo showed moderate RV systolic dysfunction in keeping with RV myocardial infarction.DiscussionRV myocardial infarction is usually due to an occlusion of the dominant RCA proximal to the origin of its RV wall branch, which often results in inferior ST elevation with reciprocal anterior ST depression. The ST elevation over V1 which would accompany RV infarction is often masked due to the more dominant electrical forces of inferior and posterior LV wall infarction. Our case demonstrates that in isolated RV infarction due to non-dominant proximal RCA occlusion, anterior ST elevation can be seen over V1-3, being most prominent in V1, which overlies the right ventricle, and resolved after restoring flow to the RCA. Spatial vector analysis of the ECG or right-sided ECG leads would be helpful to aid the diagnosis of RV infarction when clinical suspicion is present, for example when there is significant hypotension, raised jugular venous pressure but clear lung fields or deterioration after nitrate administration.

Assessment of right ventricular function in patients presenting with inferior ST segment elevation myocardial infarction and right ventricular infarction undergoing primary percutaneous intervention by different echocardiographic modalities in correlation with angiographic findings

Abstract Background Patients with inferior wall myocardial infarction who have right ventricular (RV) involvement appear to have a worse prognosis than those without RV involvement; infarcted RV tissue fails to offer a sufficient preload which is essential for adequate LV performance. Thus, assessment of RV function is an important step in dealing with patients presenting with inferior wall myocardial infarction that will help in adopting a proper management plan. Objective To assess the correlation between RV function and angiographic findings in patients presenting with inferior wall myocardial infarction associated with RV infarction undergoing primary percutaneous coronary intervention. Patients and Methods Study included 60 patients who presented to Ain shams university hospitals by inferior wall ST segment elevation myocardial infarction associated with RV infarction during the period from February 2019 to August 2019.All patients were subjected to history taking, clinical examination, ECG recording then primary percutaneous coronary intervention. Echocardiographic assessment was done to all patients within 48 hours of admission. Results Study included 60 patients, 43 males (71.7%) and 17 females (28.3%), with mean age of 56.73 ± 9.94 years. Commonest Infarction related Artery (IRA) associated with impaired RV function was proximal RCA (p-value: 0.003). In 23 patients (38.3%) heavy thrombus burden was found while in the other 37 patients (61.7%) there was no evidence of heavy thrombus burden. Regarding post procedural TIMI flow grade: 1 patient (1.7%) had final TIMI I flow, 9 patients (15.0%) had final TIMI II flow and 50 patients (83.3%) had final TIMI III flow. There was statistically significant relationship between RV function assessed through measuring RV free wall strain and both of thrombus burden and final TIMI flow grade. Abnormal RV function was more commonly associated with heavy thrombus burden (p-value:0.023) and less than TIMI III flow after angioplasty (p-value:0.011).RV free wall systolic strain assessment had highest accuracy (75%) in detection of proximal RCA occlusion compared to other parameters including TAPSE, S’ and FAC. Conclusion Impaired RV function in patients presenting with RV infarction can be predicted by different angiographic findings. Proximal RCA total occlusion being commonest IRA associated with impaired RV function. Also, presence of heavy thrombus burden and less than TIMI III flow after angioplasty are associated with increased risk of impaired RV function. RV free wall strain measured by 2D-speckle tracking echocardiography has highest accuracy in detection of proximal RCA occlusion compared to other echocardiographic indices including TAPSE, S’ and FAC.

The pulmonary annular motion velocity assessed using tissue Doppler imaging could predict the proximal right coronary artery occlusion in patients with inferior myocardial infarction

Objective: The right ventricle myocardial infarction (RVMI) is one of the leading reasons for right ventricle(RV) dysfunction. RVMI occurs in 20-50% of inferior infarctions. Echocardiography was applied to study RV involvement and proximal right coronary artery (RCA) occlusion in individuals with acute inferior MI. The objective of this study was to investigate if pulmonary annulus motion velocity (PAMVUT) levels in individuals with acute inferior myocardial infarction were linked to proximal RCA lesions.
 Method: The study comprised 50 people who had been diagnosed with acute inferior myocardial infarction and had culprit lesions in the right coronary artery. The RCA occlusion in Group A was proximal to the right ventricular branch, while the RCA occlusion in Group B was distant to the RV branch. The PAMVUT was tested, as well as other echocardiographic parameters.
 Results: In terms of metrics indicating right ventricular function, there were substantial disparities between the groups. A favorable association was established in the univariate correlation analysis between PAMVUT and RV TAPSE, with FAC, and with St.PAMVUT was identified as an independent predictor of proximal RCA occlusion in a multivariate logistic regression test. In the ROC analysis, PAMVUT

English

BACKGROUND A significant number of patients with acute Inferior wall infarction will have RV dysfunction and most of them have occlusion of either right or left circumflex coronary artery. But RV assessment is not done routinely in echocardiographic examination. Patients present with inferior wall myocardial infarction (IWMI) subsequently develop right ventricular myocardial infarction (RVMI) and have poor prognosis. In this study we wanted to evaluate the incidence of RVMI and the role of echocardiography in assessing RV function and its impact in predicting infarct related artery by angiographic analysis in acute IWMI after thrombolysis. METHODS 86 patients with acute IWMI after thrombolysis were randomly selected. Echocardiographic examination of RV function was performed within 72 hours after thrombolysis. We applied RV echo parameters like FAC (Fractional Area Change %), TAPSE (Tricuspid Annular Plane Systolic Excursion), RV S’ (RV Systolic Excursion Velocity) and MPI (Myocardial Performance Index) to assess RV function. 48 patients underwent coronary angiogram which included 10 patients with normal RV function, rest with RV dysfunction. RESULTS Among 86 patients, we compared 64 patients of RV dysfunction with 22 patients having normal function. Echo indices were significantly lower in RV dysfunction group. FAC ( 27 ± 5.95 vs 45 ± 5.4 ) TAPSE (8.5 ± 2.0 19.59 ± 2.8 ), RV S’ ( 5.78 ± 1.26 vs 17.2 ± 3.5 ) and RVMPI (0.22 ± 0.03 vs 0.57± 0.03). Angiographic analysis of 28 of 38 patients with RV dysfunction showed significant proximal lesion in RCA as compared to only 2 among 10 patients with normal RV function. CONCLUSIONS Conventional echo examination will underestimate RV dysfunction hence we applied echo parameters like FAC, TAPSE, RV S’ and RVMPI and a significant proportion of thrombolysed acute IWMI patients were found to have RV dysfunction and it was also helpful in the prediction of infarct related artery which would be predominantly a critical proximal RCA occlusion. KEY WORDS RVMI (Right Ventricular Myocardial Infarction), FAC (Fractional Area Change %), TAPSE (Tricuspid Annular Plane Systolic Excursion), RV S’ (RV Systolic Excursion Velocity) ,MPI (Myocardial Performance Index), IRA ( Infarct Related Artery)

Right Atrial Volume Index as a Predictor of Persistent Right Ventricular Dysfunction in Patients with Acute Inferior Myocardial Infarction and Proximal Right Coronary Artery Occlusion Treated with Primary Percutaneous Coronary Intervention.

ObjectivesPatients with right ventricular (RV) infarctions associated with inferior infarctions have higher rates of adverse events than isolated inferior infarctions. Right atrial volume index (RAVI) has recently been described as a predictor of clinical outcome in patients with chronic systolic heart failure and pulmonary hypertension. The aim of this study is to assess the ability of RAVI to predict the persistent RV dysfunction after acute inferior STEMI due to occlusion of proximal RCA. To the best of our knowledge, this is the first study to investigate the relation between RAVI and persistent RV dysfunction in such group of patients.Patients and methodsSixty-five consecutive patients with recent first acute inferior STEMI who underwent primary percutaneous coronary intervention (PPCI) were prospectively included in the study. Echocardiographic evaluation was performed at the time of discharge and at 3 months. All the patients underwent standard echocardiographic assessment using conventional 2D and tissue Doppler imaging (TDI).ResultsPatients were divided into two groups according to right ventricular function (RVF) 3 months after acute myocardial infarction (AMI). The normal RVF group included 41 (63%) patients and the impaired RVF group included 24 (37%) patients. RAVI was significantly higher in patients with impaired RVF (p=<0.001). RAVI was a predictor of persistently impaired RV function (odds ratio = 1.786, 95% confidence interval, 1.367–2.335, p value= <0.001) and (odds ratio = 1.829, 95% confidence interval, 1.358–2.462, p value= <0.001) in univariate and multivariable logistic regression analyses respectively. In receiving operator characteristics (ROC) curve analysis, RAVI with a cutoff value ≥ 30 ml/m2 had a 87.5% sensitivity, a 92.24% specificity area under Receiving operator characteristics (ROC) curve = 0.964 for predicting persistently impaired RVF.ConclusionIn patients with inferior STEMI with proximal RCA occlusion, RAVI is an independent predictor of persistently impaired RVF with a cut-off value ≥ 30 ml/m2.

Myocardial Infarction Complicating Vasospastic Angina in a Female Patient—Case Report

Coronary artery vasospasm is an infrequent cause of acute coronary syndrome (ACS). A 50-year-old female developed persistent chest discomfort related to anterior STEMI. After an unsuccessful thrombolysis attempt, due to delay concern, the patient was then sent to the catheterization laboratory for rescue PCI. The coronary angiogram revealed a TIMI 3 flow proximal LAD significant stenosis with spastic appearance of the coronary arteries which has improved after intracoronary nitrates administration. Optical Coherence Tomography (OCT) excluded coronary artery dissection and haematoma also revealed thrombus on moderate atherosclerotic plaque. The patient was then pain-free; she was managed medically and discharged after few days of monitoring. Three weeks later, she developed transient chest pain with ST segment elevation while cycling during rehabilitation program. Provocation test by Ergonovine was positive with complete occlusion of proximal RCA (right coronary artery) complicated by transient complete heart block and shock. She was stabilized with 7 mg of intracoronary nitrates injection. She was discharged after close monitoring with calcium channel blocker and tobacco cessation. ACS may complicate prolonged coronary artery vasospasm making the diagnosis challenging. OCT may help understand ACS mechanism and exclude spontaneous coronary artery dissection. Provocation test is crucial for confirmation.

Echocardiographic assessment of right ventricle free wall strain for prediction of right coronary artery proximal lesion in patients with inferior myocardial infarction.

In this study, our objective was to evaluate right ventricular functions with speckle-tracking and conventional echocardiographic methods in patients with acute inferior myocardial infarction and to investigate the correlation between the echocardiographic parameters and the prediction of the proximal RCA lesions. 77 patients were included in this study. Patients with a RCA occluded proximal to the right ventricular branch were assigned to Group 1 and patients with an RCA occlusion distal to the right ventricle branch were assigned to Group 2. All echocardiographic examinations were carried out within 24h after PTCA, which was performed for the treatment of inferior myocardial infarction. RV TAPSE, RV TDI Sm, FAC, RV-FW strain, RV-FW SRE', RV-FW SRA' and RV E/Em which were statistically significant in univariate analysis were evaluated with the help of the multivariate logistic regression analysis. In the multivariate logistic regression test; RV-FW strain (OR 0.751, 95% CI 0.592-0.954, p = 0.019) and RV E/Em (OR 0.442, 95% CI 0.252-0.776, p = 0.004) were determined as the independent predictive parameters for proximal RCA occlusion. In the ROC analysis, RV-FW strain>- 14.75% predicted the proximal RCA occlusion with 83% sensitivity and 61% specificity (AUC = 0.81, p < 0.001) and RV E/Em > 6.25 with 68% sensitivity and 80% specificity (AUC = 0.79, p < 0.001). In this study, we demonstrated that decreased RV FW strain and increased RV E/Em were predictive parameters for the presence of the proximal RCA in patients with acute inferior MI.

VARYING DEGREES OF ADVANCED HEART BLOCKS IN ASSOCIATION WITH ACUTE INFERIOR MYOCARDIAL INFARCTION

Acute inferior myocardial infarction (MI) is often associated with heart blocks as acute occlusion of the right coronary artery (RCA) compromises flow to sinoatrial nodal and atrioventricular nodal branches that arise from the proximal and distal parts of RCA, respectively. This phenomenon can happen in up to 20% of the cases, is usually transient and rarely requires pacemaker implantation. Still, when present, it raises alarms and poses significant monitoring and management challenges to the physicians. We report a similar case where the patient presented with inferior MI complicated by complete heart block. The patient went through varying degrees of advanced heart blocks before finally reverting to normal sinus rhythm. Subsequent coronary angiogram showed total thrombotic occlusion of proximal RCA. To the best of our knowledge, such a case has not been described before in literature where a complete array of heart blocks is reported in the context of acute MI. This case illustrates the importance of recognizing advanced heart blocks in acute MI. Although usually transient, these arrhythmias need careful monitoring during the initial days after MI.

Combined ST elevation in a case of acute myocardial infarction: How to identify the infarct-related artery?

Combined ST elevation in anterior and inferior ECG leads in acute myocardial infarction is not a rarity. It is both interesting and challenging to indentify the infarct related culprit artery. We report the case of a middle aged male with acute myocardial infarction whose admission ECG shows ST elevation in lead II, III, aVF as well as from V1-V3. 90% of such cases are due to single vessel occlusion - majority due to proximal RCA occlusion and the remaining due to mid to distal LAD occlusion. ECG features to differentiate between these two vascular occlusions are discussed. In this case at hand, lead III ST elevation of 2.5 mm and V2/V3≥ 1 indicates proximal RCA as the IRA and the same has been confirmed by pre-discharge coronary angiogram .

Proximal RCA occlusion producing anterior ST segment elevation, Q waves, and T wave inversion

An ST segment elevation myocardial infarction (STEMI) that produces anterior ST segment elevation (STE) is typically caused by acute occlusion of the left anterior descending (LAD) artery. Anterior STE, however, may also be caused by acute occlusion of either the proximal right coronary artery (RCA) or the right ventricular marginal branch (RVB). It has been thought that, in contrast to occlusions of the LAD, proximal RCA/RVB occlusion rarely causes Q waves in the right precordial leads. We present a case where a proximal RCA occlusion produced not only anterior STE, but also anterior T wave inversions and anterior Q waves.

Impact of intracoronary eptifibatide on the right ventricular function in patients with acute inferior myocardial infarction

Background and aim Distal embolization during primary percutaneous coronary intervention of the proximal right coronary artery (RCA) leads to impairment of flow of right ventricular (RV) branches and RV dysfunction. Glycoprotein IIb/IIIa receptor antagonists improve microcirculation and decrease the incidence of distal embolization. In the present study we aimed to assess RV function in patients with acute inferior ST-segment elevation myocardial infarction who received intracoronary (i.c.) bolus eptifibatide, and to compare them with patients who received a standard intravenous (i.v.) dose. Patients and methods Sixty-six patients with acute inferior myocardial infarction who underwent primary percutaneous coronary intervention and whose culprit lesion was RCA proximal to major RV branch were included in the present study. Patients were divided into two groups. In the first group, 36 patients received double bolus intracoronary eptifibatide followed by i.v. infusion. In the second group, 30 patients received standard i.v. dose. Forty-eight hours after the index procedure, all the patients underwent standard echocardiography assessment of RV function using conventional two-dimensional and tissue Doppler imaging. Results There were no significant differences regarding baseline characteristics, final Thrombolysis In Myocardial Infarction (TIMI) flow, and left ventricular systolic function between the two groups. RV function indices, including tricuspid annular plane systolic excursion, myocardial performance index-tissue Doppler imaging, and RV fractional area change, were significantly better in patients who received i.c. bolus eptifibatide (P Conclusion I.c. double bolus eptifibatide followed by i.v. infusion was found to be superior to the standard i.v. dose with respect to RV function in patients with acute inferior ST-segment elevation myocardial infarction due to proximal RCA occlusion.

Feasibility of proximal right coronary artery imaging by 2D and 3D echocardiography in comparison to coronary angiography.

The present study was carried out to test the feasibility of proximal right coronary artery (RCA) imaging and to detect proximal RCA narrowing and occlusion by 2D and 3D transthoracic echocardiography in comparison to coronary angiography (CA). Standardised 2D and 3D echocardiography were performed prior to CA in 97 patients with sinus rhythm. The following parameters were determined: the longest longitudinal detectable RCA segment, the minimum and maximum width of the RCA, the area and number of detectable narrowing >50% of the proximal RCA and the correlation between the echocardiographic and angiographic findings. The visualisation of the proximal RCA and the detection of coronary artery narrowing in the proximal RCA are generally possible. Differences in width and area were not statistically significant between 2D and 3D echocardiography, but showed significant differences between echocardiography and CA. For the detection of proximal RCA narrowing, higher sensitivity and specificity values were obtained by 2D than by 3D echocardiography. However, in patients with sufficient image quality 3D echocardiography permits a more detailed visualisation of the anatomical proportions and an en-face view into the RCA ostium. The visualisation of the proximal RCA is feasible and narrowing can be detected by 2D and 3D echocardiography if image quality is sufficient. CA is the gold standard for the detection of coronary artery stenoses. However, the potential of this new approach is clinically important because crucial findings of the proximal RCA can be presumably detected non-invasively prior to CA.

CORONARY ARTERY PATHOLOGY IN RIGHT VENTRICULAR MYOCARDIAL INFARCTION

Aim. To study anatomical and functional features of coronary blood flow in myocardial infarction (MI) of left ventricular (LV) inferior wall with the involvement of right ventriculum (RV).Material and methods. The study included 120 patients who suffered MI of LV inferior wall with (Group 2 – LVMI; n=58) or without (Group 1 – RVMI; n=62) RV involvement.Results. One coronary artery (CA) was affected in 65,0% of the participants. Right CA (RCA) pathology was registered in 97,4% (n=76), while circumflex CA (CxCA) pathology was observed only in 2,6% (n=2). Involvement of two and three or more CA was observed in 26,7% and 8,3% of the patients, respectively. Single CA pathology was at least 1,3 times more common in the RVMI group (p&lt;0,05), while three or more CA were affected at least 8 times more often in the LVMI group (p&lt;0,05). The right dominant, co-dominant, and left dominant types of coronary flow were registered in 76,7%, 15,0%, and 8,3% of the patients, respectively, all of whom were from the LVMI group. In 85% and 15% of the cases, the infarct-related artery (IRA) was RCA and CxCA, respectively. Among LVMI patients, RCA was the IRA almost three times more often than CxCA; among RVMI patients, this difference was 18-fold (p&lt;0,001 for both comparisons). All LVMI patients (n=47) had distal occlusion of RCA, while all RVMI patients (n=55) had its proximal occlusion.Conclusion. Over two-thirds of the cases оf ST elevation MI of LV inferior wall with RV involvement occur in patients with the right dominant type of coronary blood flow. RVMI typically occurs in patients with right dominant type of coronary blood flow and PCA pathology. MI of LV inferior wall with RV involvement is characterised by proximal RCA occlusion.

How should I treat a patient with significant angina and a severe left anterior descending artery stenosis beyond the insertion of a left internal mammary artery jump graft (diagonal to LAD)?

BACKGROUND: A 60-year-old man with a history of previous coronary artery bypass grafting (saphenous vein grafting [SVG] to native right coronary artery [RCA] and sequential left internal mammary artery [LIMA] jump grafting to his native first diagonal [D1] and left anterior descending [LAD] arteries), who had developed a previous ischaemic cerebrovascular accident following femoral angiography, re-presented with further ischaemic cardiac symptoms. INVESTIGATIONS: Physical examination, electrocardiography, biochemistry including high-sensitive troponin, echocardiography, and trans-radial angiography. DIAGNOSIS: Severe native 3 vessel disease including ostial occlusion of the LAD, distal left circumflex and obtuse marginal (LCX/OM) disease and proximal RCA occlusion; occluded SVG to RCA, and evidence of a critical stenosis in the mid LAD distal to the insertion of the tortuous LIMA jump graft (diagonal to LAD). TREATMENT: PCI to mid LAD lesion via LIMA jump graft from left trans-radial approach.

Value of ST Segment Changes in 12 Lead ECG to Detect Proximal Versus Distal Right Coronary Artery Occlusion in Acute Inferoposterior Myocardial Infarction

Background: A history of ischemic-type discomfort &amp; the initial 12- lead ECG are the primary tools for screening patients with acute myocardial infarction in the emergency department. ST elevation in inferior leads indicates an evolving myocardial infarction of the inferoposterior wall. The outcome of patients with inferoposterior myocardial infarction due to occlusion of right coronary artery depends mainly on the location of occlusion (distal versus proximal). Hypothesis: Value of ST-segment depression in lateral leads (I and aVL) and ST-segment changes in lead V1 to predict the site of right coronary artery occlusion in the case of an inferoposterior myocardial infarction. Objective: To predict the site of right coronary artery (RCA) occlusion ( proximal or distal) in acute inferoposterior myocardial infarction by ST segment depression in leads 1 &amp; aVL and ST-segment changes( is electric/ elevated or depressed) in V1.Methods and Results: A total of fifty four patients of ST-segment elevation inferoposterior wall AMI due to suspected RCA occlusion, admitted within 12 hours of onset of chest pain, and subsequently underwent coronary angiography during hospitalization, were selected for the study. Patients were divided into two groups on the basis of angiographic findings: proximal RCA occlusion (group I) and distal RCA occlusion (group II). A 12 lead ECG was taken on admission. ST segment deviation in lateral leads (I &amp; aVL) as well as in precordial lead (V1) was calculated. Isoelectric or elevated ST-segment in V1 predicted proximal RCA occlusion whereas depressed ST-segment predicted distal RCA occlusion. It was demonstrated that, STsegment changes in precordial lead (V1) was a sensitive &amp; specific marker to discriminate proximal &amp; distal RCA occlusion in inferoposterior wall AMI with high positive &amp; negative predictive value, but ST-segment changes in lateral leads (I &amp; aVL) although more specific for proximal RCA occlusion did not seem to be of clinical value due to its low sensitivity. DOI: http://dx.doi.org/10.3329/uhj.v7i2.10844 University Heart. Journal Vol. 7, No. 2, July 2011

Automated discrimination of proximal right coronary artery occlusion from middle-to-distal right coronary artery occlusion and left circumflex occlusion in ST-elevation myocardial infarction

BackgroundClassifying the location of an occlusion in the culprit artery during ST-elevation myocardial infarction (STEMI) is important for risk stratification to optimize treatment. We developed a new logistic regression (LR) algorithm for 3-group classification of occlusion location as proximal right coronary artery (RCA), middle-to-distal RCA or left circumflex (LCx) coronary artery with inferior myocardial infarction. We compared the performance of the new LR algorithm with the recently introduced decision tree classifier of Fiol et al (Ann Noninvasive Electrocardiol. 2004;4:383-388) in the classification of the same 3 categories. MethodsThe new algorithm was developed on a set of electrocardiograms from an emergency department setting (n = 64) and tested on a different set from a prehospital setting (n = 68). All patients met the current STEMI criteria with angiographic confirmation of culprit artery and occlusion location. Using LR, 4 ST-segment deviation features were chosen by forward stepwise selection. Final LR coefficients were obtained by averaging more than 200 bootstrap iterations on the training set. In addition, a separate 4-feature classifier was designed adding ST features of V4R and V8, only available in the training set. ResultsThe LR algorithm classified proximal RCA occlusion vs combined LCx occlusion and middle-to-distal RCA occlusion, with a sensitivity of 76% and specificity of 81% as compared with 71% and 62% for the Fiol classifier. The difference in specificity was statistically significant. The LR classifier trained with additional ST features of V4R and V8, but still limited to 4, improved the overall agreement in the training set from 65% to 70%. ConclusionDiscrimination of proximal RCA lesion location from LCx or middle-to-distal RCA using the new LR classifier shows improvement over decision tree–type classification criteria. Automated identification of proximal RCA occlusion could speed up the risk stratification of patients with STEMI. The addition of leads V4R and V8 should further improve the automated classification of the occlusion site in RCA and LCx.

Introducing a new algorithm in inferior ST-segment elevation myocardial infarction to predict the culprit artery and distinguish proximal versus distal lesions

Inferior ST-elevation myocardial infarction (I-STEMI) caused by proximal occlusion of the left circumflex artery (LCx) or right coronary artery (RCA) is associated with poor outcomes. We tested two new electrocardiographic (ECG) algorithms to identify proximal RCA (P-RCA), proximal LCx (P-LCx), or distal RCA or LCx in I-STEMI. In 135 patients with I-STEMI, 115 (85.2%) had RCA occlusion [49 (36.3%) with P-RCA occlusion] and 15 (11.1%) had LCx occlusion [4 (2.9%) with P-LCx occlusion]. In the ECG algorithms, P-RCA occlusion was indicated by STE in lead III higher than lead II and no ST depression in V₁. P-LCx occlusion was indicated by STE in lead II higher than in lead III and no ST depression in aVL. One algorithm included an additional step: whether the ST-T pattern in aVL represents reciprocal changes to lead III (differences in the magnitude of ST deviation or T-wave direction were considered to indicate P-LCx occlusion). The positive and negative predictive values of these algorithms were low (45.6 and 76.8% for P-RCA occlusion and 6.7 and 97.5% for P-LCx occlusion). The ECG algorithms cannot reliably identify the culprit artery in I-STEMI. Right precordial leads may be needed to determine the site of lesion.

Transthoracic echocardiography in the detection of chronic total coronary artery occlusion

The aim of our study was to detect chronic total occlusion of the left anterior descending coronary artery (LAD), circumflex coronary artery (Cx), and right coronary artery (RCA) using transthoracic echocardiography (TTE) in 110 consecutive patients who underwent coronary angiography for investigation of angina. Coronary blood flow direction was assessed in the epicardial collaterals [distal LAD (dLAD), obtuse marginal branches and right posterior descending artery (PDA)] and intramyocardial collaterals [LAD septal branch (SB LAD) and RCA septal branch (SB RCA)]. The sensitivity and specificity of retrograde flow for identification of the occluded LAD by TTE in the dLAD only were 78 and 96%, respectively, and those in both dLAD and SB LAD were 89 and 96%, respectively. The retrograde SB LAD flow detects proximal LAD occlusion with 88% sensitivity and 75% specificity. The sensitivity and specificity of retrograde flow for identification of the occluded RCA by TTE in the PDA only were 79 and 97%, respectively, and those in both PDA and SB RCA were 89 and 97%, respectively. The retrograde SB RCA flow does not allow us to differentiate between proximal and non-proximal RCA occlusion. Transthoracic echocardiography is not a method for diagnosing Cx occlusions as the success in visualizing the Cx epicardial collaterals was achieved in 31% of cases only. TTE is a sensitive and highly specific non-invasive method for diagnosis of LAD and RCA occlusions, based on the detection of the coronary blood flow direction in the epicardial and intramyocardial collaterals.

New criteria based on ST changes in 12-lead surface ECG to detect proximal versus distal right coronary artery occlusion in a case of acute inferoposterior myocardial infarction.

The outcome of patients with inferoposterior myocardial infarction (MI) due to occlusion of right coronary artery (RCA) depends mainly on the location of occlusion (distal vs. proximal). The aim of this study was to evaluate the value of new ECG criteria: the sum of ST depression in I and VL leads and ST changes in V1 lead to predict the location of RCA occlusion in the case of an inferoposterior MI. The ECG and angiographical findings of 50 patients with acute inferoposterior MI due to RCA occlusion were analyzed. The value of new criteria was studied alone and in combination to predict proximal versus distal RCA occlusion and compared with previously described criterion based only on ST changes in VL. Isoelectric or elevated ST in V1 allowed predicting proximal RCA occlusion with 70% sensitivity and 87% specificity with high positive and negative predictive value (87% and 71%, respectively). The new criterion of the sum of ST depression in I and VL >or= 5.5 mm compared to the criterion based only on ST depression in VL was also more specific (91% vs. 72%) for proximal RCA occlusion with better positive and negative predictive values. The new criterion based on the ST changes in V1 lead is highly accurate in detecting the location of occlusion in the RCA compared to the criteria based only on ST changes in lateral leads. The use of this criterion might increase the accuracy of ECG-based identification of myocardial involvement in acute inferoposterior MI.