Nondominant Right Coronary Artery Research Articles

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.

Inferior myocardial wall ischemia on SPECT-MPI in patients with non dominant right coronary artery and non significant coronary artery disease

BackgroundThe impact of a non-dominant right coronary artery (NDRCA), on single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI)has not been clarified. Methods and resultsWe compared SPECT-MPI results of consecutive patients without significant (diameter stenosis ≥50%)coronary artery disease (CAD) and a NDRCA (Group-1), with those of patients from our database without CAD and a dominant RCA (Group-2). All patients were subjected to SPECT-MPI with I.V. infusion of adenosine, and TC99-tetrofosmin. Group-1 included 69 patients (55 men, 79.7%), mean age 66.8 ± 9.8 years. Group-2 consisted of 79 patients (56 men, 70.9%), mean age 62.7 ± 11.5. There was no difference in demographics and CAD risk factors between the two groups. The SPECT-MPI revealed inferior wall ischemia, in 35 patients (50.7%), in Group-1 and 27 patients (34.1%), in Group-2 (P = 0.041). ConclusionsA relatively high rate of reversible SPECT-MPI perfusion defects may be anticipated in patients with an unobstructed NDRCA compared to patients with a dominant RCA.

Atypical location of ST elevation acute myocardial infarction in relation to the electrocardiogram

Introduction. Electrocardiography is an initial non-invasive diagnostic algorithm for ST elevation acute myocardial infarction. Specific electrocardiographic phenomenon is described, when the occlusion of the proximal segment of the right coronary artery or the isolated occlusion of its ventricular branch is presented with ST elevation in the precordial leads. Case Report. A 78-year-old woman was admitted as an emergency due to chest pain and electrocardiographically recorded concave elevation in leads V1 - V3. She was diagnosed with ST elevation myocardial infarction of the anterior region and sent to catheterization laboratory for emergency coronary angiography. It showed an occlusion of the proximal-medial right coronary artery. Behind the occlusion, the right coronary artery, posterior descending artery and posterior lateral artery, a hetero-collateral circulation was seen. Two drug-eluting stents were implanted into the proximal segment of the right coronary artery. Discussion. The phenomenon of acute myocardial infarction caused by occlusion of the proximal right coronary artery and/or ventricular branches of the right coronary artery, presenting with ST segment elevation in the precordial leads, is a consequence of several anatomical variations: occlusion of nondominant right coronary artery, isolated occlusion of the ventricular branch of the right coronary artery, and the occlusion of the right coronary artery proximal to the ventricular branch with hetero collateral circulation on the periphery of the right coronary artery, like in our case. Electrocardiographic characteristic pointing to the occlusion of the proximal right coronary artery and/or ventricular branches of the right coronary artery is higher ST elevation in the lead V1 than in the other leads, followed by the absence of Q wave development. This ST elevation is concave. Conclusion. It is necessary to emphasize the significance of differential diagnosis of culprit lesion in patients with chest pain and elevation of the ST segment in the precordial leads having in mind further different thera peutic algorithms. Patients with right ventricular myo cardial infarction need to maintain an adequate ?preload? and avoid vasodilators in order to maintain the right ventricular stroke volume.

Acute Inferior Myocardial Infarction Presenting as Anterior ST Segment Elevation Myocardial Infarction on ECG

A 51-year-old man presented to the emergency department with acute substernal chest pain. ECG showed ST-segment elevation in the left precordial leads. Coronary angiography demonstrated an occlusion of the right coronary artery (RCA) and no significant stenosis in left anterior descending coronary artery (LAD). The occlusion of a non-dominant RCA may result in anterior ST-segment elevation ECG changes, which could disorient both general and interventional cardiologists.

Significance of inferior wall ischemia in non-dominant right coronary artery anatomy.

AIMTo investigate the relationship of inferior wall ischemia on myocardial perfusion imaging in patients with non-dominant right coronary artery anatomy.METHODSThis was a retrospective observational analysis of consecutive patients who presented to the emergency department with primary complaint of chest pain. Only patients who underwent single photon emission computed tomography (SPECT) myocardial perfusion imaging (MPI) were included. Patients who showed a reversible defect on SPECT MPI and had coronary angiography during the same hospitalization was analyzed. Patients with prior history of coronary artery disease (CAD) including history of percutaneous coronary intervention and coronary artery bypass graft surgerys were excluded. True positive and false positive results were identified on the basis of hemodynamically significant CAD on coronary angiography, in the same territory as identified on SPECT MPI. Coronary artery dominance was determined on coronary angiography. Patients were divided into group 1 and group 2. Group 1 included patients with non-dominant right coronary artery (RCA) (left dominant and codominant). Group 2 included patients with dominant RCA anatomy. Demographics, baseline characteristics and positive predictive value (PPV) were analyzed for the two groups.RESULTSThe mean age of the study cohort was 57.6 years. Sixty-one point seven percent of the patients were males. The prevalence of self-reported diabetes mellitus, hypertension and dyslipidemia was 36%, 71.9% and 53.9% respectively. A comparison of baseline characteristics between the two groups showed that patients with a non-dominant RCA were more likely to be men. For inferior wall ischemia on SPECT MPI, patients in study group 2 had a significantly higher PPV, 32/42 (76.1%), compared to patients in group 1, in which only 3 out of the 29 patients (10.3%) had true positive results (P value < 0.001 Z test). The difference remained statistically significant even when only patients with left dominant coronary system (without co-dominant) were compared to patients with right dominant system (32/40, 76.1% in right dominant group, 3/19, 15.8% in left dominant group, P value < 0.001 Z test). There was no significant difference in mean hospital stay, re-hospitalization, and in-hospital mortality between the two groups.CONCLUSIONThe positive predictive value of SPECT MPI for inferior wall ischemia is affected by coronary artery dominance. More studies are needed to explain this phenomenon.

Isolated Nondominant Right Coronary Stenosis

The frequency, clinical presentation, and management of severely stenotic isolated nondominant right coronary artery (NDRCA) have not been adequately defined. We sought to do so in a large cohort of patients undergoing coronary angiography. We retrospectively analyzed all patients who underwent coronary angiography in our institute between 1995 and June 2012, looking at those with a severe lesion in the NDRCA, recording demographic, clinical, and angiographic data. Of the 43,327 patients, 35 (0.08%) were found to have a severely stenotic NDRCA as a single-vessel disease. The most common indication for catheterization was acute coronary syndrome (49%). Most of the patients were managed conservatively (66%) and the entire group had a relatively benign course, with no coronary deaths. Severe stenosis of the NDRCA as isolated disease is a very rare entity, and although most commonly presenting with acute coronary syndrome, conservative management was the usual approach.

The severity of ST-segment elevation in acute inferior myocardial infarction: does it predict the presence of a proximal culprit lesion along the right coronary artery course?

OBJECTIVE Acute inferior myocardial infarction (AIMI) is generally characterized by ST segment elevation in the limb leads (D2, D3, aVF). Many trials have reported the close relation between the severity of this ST segment elevation and the extent of infarction, and also the prognosis. Based on the clinical studies, several electrocardiographic (ECG) criteria have also been propounded to identify the infarct-related artery. This study was conducted to investigate the possible relation between the severity of ST segment elevation and the proximity of the culprit lesion along the right coronary artery (RCA) course in AIMI. METHODS Sixty patients (31 female, 29 male) admitted to our centre with diagnosis of first AIMI were included in the study. All cases underwent coronary angiography (CAG) on the 6th day of hospitalization. Patients with non-dominant RCAs were excluded from the study. The lesion with the highest degree of stenosis along the RCA course was accepted as the culprit lesion. The RCA was divided into 3 segments: proximal portion (from ostium to the first acute marginal (AM) artery), midportion (from the first AM to the last AM), distal portion (from the last AM on). In each case, a single value (STSE) was obtained by the addition of the amplitudes (mm) of ST segment elevation in the limb leads (D2, D3, aVF) during the hyperacute stage of AIMI. RESULTS The patients with the culprit lesions in the proximal portion of the RCA were found to have a mean STSE value of 12.61+/-3.79 mm, while the patients having the culprit lesions in the mid and distal portions were found to have mean STSE values of 6.88+/-1.20 mm and 5.05+/-0.97 mm, respectively. There was a significant positive correlation between the severity of ST segment elevation and the culprit lesion proximity (r=0.82, p<0.01 for the proximal and r=0.7, p<0.05 for the mid portions of RCA). CONCLUSION In AIMI, the severity of ST segment elevation and the proximity of the culprit lesion along the infarct-related RCA was found to be closely related, indicating the informative feature of ST segment elevation in the prediction of culprit lesion location.

Clinically Significant Nondominant Right Coronary Artery Disease

The literature is scarce regarding the management of ischemia due to disease of the nondominant right coronary artery (NDRCA). We describe two patients who suffered from myocardial ischemia due to significant disease of the NDRCA. Both were managed with balloon angioplasty. Disease of the NDRCA can be a source of ischemia and should be dealt with like other coronary vessels. (J Interven Cardiol 1996;9:59–64)

Prevalence of Angiographically Recognizable Atherosclerosis in Non-Dominant Right Coronary Arteries

Among 1,000 consecutive patients referred for coronary arteriography because of chest pain, 89 patients were found to have a non-dominant right coronary artery (NDRCA). These patients were compared to 89 consecutive patients with dominant right coronary artery (DRCA) matched for age, sex, smoking and serum cholesterol. There was a lower incidence of obstructive disease in NDRCA (23 of 89 patients, 26%) than in DRCA (55 of 89 patients, 62%), X2 = 23.368, p less than 0.001. The incidence of coronary disease was also lower in the NDRCA group, 50 of 89 patients (56%), than in the DRCA group, 68 of 89 patients (76%), X2 = 8.146, p less than 0.01. When only patients with coronary artery disease (CAD) were included in the analysis: 23 of 50 (46%) patients with CAD and NDRCA had obstructive disease in the right coronary artery (RCA) while 55 of 68 (80%) patients with DRCA and CAD had obstructive disease in the RCA, X2 = 15.646, p less than 0.001. The lower incidence of disease in NDRCA persisted even when only the proximal one-third of the DRCA was considered: 41 of 89 (46%) patients with DRCA had proximal lesions compared to the total length of NDRCA, 23 of 89 patients (26%), X2 = 7.940, p less than 0.01.(ABSTRACT TRUNCATED AT 250 WORDS)