Dominant Right Coronary Artery Research Articles

Spontaneous Vanishing of Coronary Collaterals During Cardiac Catheterization for Acute Myocardial Infarction

A patient with acute ST segment elevation inferior myocardial infarction underwent urgent cardiac catheterization. Left coronary arteriography demonstrated minor coronary disease with well-defined collateral filling of the dominant right coronary artery. Shortly thereafter, right coronary arteriography demonstrated entirely normal findings, and a repeat left coronary angiogram no longer demonstrated coronary collaterals. The “vanishing” coronary collaterals are consistent with acute myocardial infarction from transient occlusion of the right coronary artery. These findings are consistent with the phenomenon of myocardial infarction in the presence of angiographically normal coronary arteries. The transient coronary occlusion in this patient is likely secondary to spontaneous lysis of intracoronary thrombus or transient coronary vasospasm. J Med Cases. 2016;7(12):527-530 doi: https://doi.org/10.14740/jmc2667w

Diagnostic performance of standard electrocardiogram for prediction of infarct related artery and site of coronary occlusion in unselected STEMI patients undergoing primary percutaneous coronary intervention

To evaluate the relationship between ECG patterns and infarct related artery (IRA) in an all-comer population with ST-segment elevation myocardial infarction (STEMI) and validate current criteria for identifying IRA (right coronary artery (RCA) versus left circumflex artery (LCA)) in inferior STEMI and for diagnosing left main (LM) or left anterior descendent artery occlusion (LAD) in anterior STEMI. We retrospectively analysed ECGs at presentation and coronary angiogram in 885 consecutive patients undergoing primary percutaneous coronary intervention. Six ECG patterns were identified: anterior-STEMI (n=433; 49.0%), inferior-STEMI (i=365; 43.0%), lateral-STEMI (n=43; 5.0%), left bundle branch block (n=26; 3.0%), posterior-STEMI (n=7; 1.0%) and de Winter sign (n=7; 1.0%). The last two ECG patterns were univocally associated with LCA and proximal LAD occlusion respectively. In patients with inferior STEMI, predefined ECG algorithms showed high sensitivity(>90%) for RCA occlusion and high specificity(>90%) for LCA. The diagnostic performance was mainly determined by RCA dominance. In anterior STEMI the vectorial analysis of ST deviation in both frontal and horizontal planes could identify patients with LM/proximal LAD occlusion (adjusted-odds ratio for in-hospital mortality =2.45, 95% confidence interval: 1.31-4.56, p = 0.005) with low sensitivity (maximum 60%; using ST-depression in lead II, III, aVF + ΣSTE aVR + V1-ST depression V6≥0) and high specificity (maximum 95%; using ST-depression in inferior leads + ST-depression in V6). In STEMI undergoing primary percutaneous coronary intervention, six ECG patterns can be identified with a non-univocal relationship to the IRA. In inferior STEMI, vectorial analysis of ST deviation identifies IRA with a high appropriateness only when RCA is the dominant artery. In anterior STEMI, criteria derived from both frontal and horizontal planes identify LM/proximal LAD occlusion with high specificity but low sensitivity.

Prevalence and characteristics of coronary artery anomalies in 12401 adult patients: a coronary angiographic study from Northern Greece

Purpose: Since regional and ethnic variations of the incidence of CAA have been reported, our aim was to estimate their incidence in a population from Northern Greece, which has not been previously studied. Methods: A series of 12401 coronary angiograms, performed between January 2003 and December 2011 in a cardiac catheterization unit at our institution was retrospectively reviewed for the presence of coronary artery anomalies. Results: The overall incidence of isolated coronary artery anomalies was 1.35% (167/12401, mean age: 62.9±11.6 years, males: 74.3%). The most common coronary anomaly was separate ostia for Left Anterior Descending artery (LAD) and circumflex artery (Cx) inside the left sinus of Valsava (SoV), with an incidence of 0.48% (59/12401) or 35.3% of all coronary anomalies. The second most common anomaly was origin of Cx from the right side with an incidence of 0.35% (43/12401) or 25.7% of all coronary anomalies. Regarding the anomalous origin of the Cx from the right SoV, three distinct anatomical variants of the ostium of the anomalous left circumflex coronary artery were identified: a) separate ostia for Right Coronary Artery (RCA) and anomalous circumflex within the right sinus of Valsalva (type I, n=20, 46.5%), b) common ostia in the right sinus (type II, n=13, 30.2%), and c) Cx arising arising as a branch of the proximal RCA (type III, n=10, 23.3%). In all cases the anomalous Cx had a posterior course to the aorta. Anomalous RCA origin was found in 41 cases (0.33% or 24.6% of all coronary anomalies). It originated separately from the left sinus of Valsalva (SV) in eighteen patients (an incidence 0.14% or 10.8% of all anomalies). A single coronary artery arising from the right SoV was seen in four patients (0.03% or 2.4% of anomalies). An absent circumflex or super-dominant RCA in 2 cases (0.02% or 1.2% of anomalies). In this series we also found also seventeen cases of coronary fistulas (0.13% or 10.2% of anomalies). In one patient coronary angiography revealed congentital left main coronary artery atresia (0.008%) with a dominant RCA providing intercoronary retrograde collateral to the left anterior descending artery (LAD) and left circumflex artery (LCx). Conclisions: The incidence of coronary artery anomalies in our study population was 1.35%. The most common type was separate ostia for LAD and Cx inside the left SoV and second most common the origin of the Cx from the right sinus of Valsalva. Although geographic variations in the incidence of CAA have been reported, these results are in agreement with previously published large angiographic series.

A tale of two coronaries

A 43-year-oldmanwith hypercholesterolemia and a family history of premature coronary artery disease (CAD) was referred for a coronary calcium scan to screen for the presence of significant CAD. Following a coronary calciumscore of 10Agatstonunits and symptoms of atypical chest discomfort, the patient was referred for coronary computed tomography angiography (CCTA). This demonstrated the presence of an anomalous right dominant coronary artery (RCA) arising off the left coronary cusp. The RCA was stenosed at its origin (50–75%) and followed an acute course between the main pulmonary artery and the ascending aorta (Fig. 1a and b). Based on the results of the CTCA, the patient was referred for an exercise myocardial perfusion scan (rest/stress sestamibi) where he was able to achieve 16 min (18 METS) without significant cardiovascular symptoms. On rest/stress gated single photon emission computed tomography (SPECT) there were no perfusion or wall motion abnormalities. One month later, this man's older brother, aged 55 years, was also screened for coronary artery disease based on cardiovascular risk factors of smoking, hypercholesterolemia and a family history of premature coronary artery disease. Following an abnormal coronary calcium score of 80 Agatston units, CCTA was performed. This demonstrated almost identical coronary anatomy to that of his brother (Fig. 2a and b). The patient was referred for an exercise stress echocardiogram where he was able to achieve 17 min with no cardiovascular symptoms, echocardiographic or hemodynamic abnormalities.

Electrocardiographic characteristics in angiographically documented occlusion of the dominant left circumflex artery with acute inferior myocardial infarction: limitations of ST elevation III/II ratio and ST deviation in lateral limb leads

Background The prognosis of dominant left circumflex artery (LCx) occlusion-related inferior acute myocardial infarction (AMI) patients is poor, but the electrocardiographic (ECG) characteristics of this AMI entity have not been described. Methods One hundred thirty-five patients with first dominant right coronary artery (RCA) or dominant LCx-related inferior AMI were included. The characteristics of ECG obtained on admission for 55 patients with culprit lesions proximal to the first major right ventricular (RV) branch of dominant RCA (group proximal dominant RCA), 62 patients with culprit lesions distal to the first major RV branch of dominant RCA (group distal dominant RCA), and 18 patients with culprit lesions in dominant LCx (group dominant LCx) were compared. Results There were no significant differences among the 3 groups in the prevalence regarding an S/R ratio greater than 1:3 in aVL, ST elevation in aVR (ST↑ aVR), ST depression in aVR (ST↓ aVR) of 1 mm or more, and atrioventricular block. Greater ST elevation in lead III than in II and greater ST depression in aVL than I showed specificity of 17% and 44% to identify dominant RCA as culprit lesion, respectively. All 3 groups could be distinguished on the basis of ST↑ V4R, ST↓ V4R, ST↓ V3/ST↑ III of 1.2 or less, and ST↓ V3/ST↑ III of more than 1.2. Conclusions Greater ST elevation in lead III than in II, greater ST depression in aVL than I, and an S/R ratio of greater than 1:3 in aVL were not useful to discriminate between dominant RCA and dominant LCx occlusion-related inferior AMI. ST-segment deviation in lead V 4R and the ratio of ST↓ V3/ST↑ III were useful in predicting the dominant artery occlusion-related inferior AMI.

Emergency Percutaneous Coronary Intervention in the Setting of a Single Left Coronary Ostium

A 34-year-old man with no significant cardiac risk factors presented with an anterolateral ST-elevation myocardial infarction and was transferred to our institution for rescue percutaneous coronary intervention after failed thrombolysis. At the time of the procedure, he had ongoing chest pain, and there was persistent ST-segment elevation on the ECG. The right coronary artery (RCA) could not be located with a series of diagnostic catheters. Diagnostic images of the left coronary artery showed the circumflex artery and an aberrant dominant RCA arising from the left main stem but, despite multiple views, the left anterior descending artery could not initially be identified (Figure 1; Videos 1 and 2). An aortogram demonstrated only a single coronary ostium in the left coronary sinus. After re-engaging the left coronary artery for further diagnostic images, the left anterior descending artery was finally identified, which was occluded at its ostium and visible in one view only (Figure 2; video 3). After guide wire passage, flow was restored in the culprit vessel and subsequent intervention was uncomplicated with a single 3-mm bare metal stent deployed (Figure 3; Videos 4 through 6). There was TIMI 3 flow at the end of …

Effect of Intracoronary Shunt on Right Ventricular Function During Off-pump Grafting of Dominant Right Coronary Artery with Poor Collateral

Although numerous studies have validated the efficacy of intracoronary shunt on reducing left ventricular dysfunction during off-pump coronary artery bypass surgery (OPCAB), there is lack of evidence supporting its role on right ventricular (RV) function during right coronary artery (RCA) revascularization. Therefore, we studied the effect of intracoronary shunt during grafting of dominant RCA without visible collateral supply on global RV function using thermodilution method. Forty patients scheduled for multivessel OPCAB with right dominant coronary circulation without collateral supply confirmed by angiography were randomized to RCA revascularization either with a shunt (n=20) or soft snare occlusion (n=20). RV ejection fraction (RVEF) was recorded at baseline, during RCA grafting, and 15 min after reperfusion. Corresponding RV stroke work index (RVSWI) was calculated. RVEF and RVSWI decreased significantly during RCA grafting and returned to baseline values after reperfusion in both groups without any significant differences between the groups. Intracoronary shunt did not exert any beneficial effect on global RV function during RCA grafting, even in the absence of visible collateral supply. Regarding the possibility of graft failure by intracoronary shunt-induced endothelial damage, routine use of intracoronary shunt during RCA grafting is not recommended in patients with preserved biventricular function.

SEVERE MYOCARDIAL ISCHEMIA DUE TO A LARGE ARTERIOVENOUS MALFORMATION OF THE LEFT ANTERIOR DESCENDING CORONARY ARTERY WITH FISTULOUS CONNECTION FROM THE RIGHT CORONARY ARTERY.

Coronary artery fistulae (CAF) are unusual, mostly congenital abnormalities in which coronary blood bypasses the myocardial capillary network and is shunted into a great vessel, cardiac chamber, or other structure. We present a rare variant of a CAF arising from the right coronary artery (RCA) with termination in a large arteriovenous malformation (AVM) of the left anterior descending (LAD) artery that resulted in chronic severe myocardial ischemia. A 58-year-old black woman with a history of hypertension was referred for the evaluation of a severe, cramping, nonradiating, exertional chest pain after starting an exercise program. The only abnormal finding on physical examination was an elevated blood pressure of 148/98 mm Hg. Her resting electrocardiogram (ECG) showed anterolateral T-wave inversions and her peak exercise stress ECG showed inferior and anterolateral 3 mm ST depression. Myocardial perfusion study revealed a reversible 50% perfusion defect involving the apical, anterior, anteroseptal, and inferior segments of the left ventricle. Transient ischemic dilatation of the left ventricular cavity was also noted on stress imaging. Cardiac catheterization showed a left ventricular end-diastolic pressure of 25 mm Hg with an ejection fraction of 70% with no wall motion abnormalities. However, coronary angiography revealed an intramyocardial proximal LAD with a large, grape-like AVM with fistulous drainage from a dominant RCA. The patient had a single-vessel bypass surgery of her LAD AVM using the left internal mammary artery. The RCA fistula was not amenable to ligation. Her postoperative period was complicated by pulmonary embolism, which was adequately managed with anticoagulation. On subsequent follow-up visits, she had improved exercise tolerance with no anginal symptoms. A repeat myocardial perfusion scan performed a few months after the coronary bypass showed normal myocardial perfusion. The exertional chest pain in this patient was due to coronary steal from the large LAD AVM and its fistulous RCA connection, which resulted in severe ischemia of the myocardial segments perfused by the LAD distally. This severe ischemia was successfully resolved with a single-vessel coronary bypass surgery.

Does Coronary Artery Size Really Matter?

To evaluate ischemia in right ventricle (RV) in patients with small caliber of right coronary artery (RCA). The study population consisted of 60 consecutive patients undergoing coronary angiography within 3 months. The patients were divided into three different groups according to lumen diameter of RCA and coronary dominance. Group 1, 2, and 3 consisted of patients with small diameter of RCA, dominant RCA, and dominant circumflex artery, respectively. RV ischemia was assessed by using pulse-wave tissue Doppler sampling obtained from RV free wall close to the lateral tricuspid annulus at the apical four-chamber view during dobutamine stress echocardiography (DSE). When the mean systolic velocity percentages of increase from low to peak dose dobutamine in patients with small RCA were compared to those of other groups, statistically significant difference was found between group 1 and the other groups (P = 0.007 for group 1 vs group 2; P = 0.01 for group 1 vs group 3). The mean systolic velocity at peak dobutamine dose of patients with small caliber of right coronary artery was statistically lower than the other groups (P = 0.001 for group 1 vs group 2, P < 0.001 group 1 vs group 3). There are a group of patients with small diameter of RCA causing probable ischemia in RV and small caliber of RCA can really matter in these patients.

Effect of Primary Angioplasty on Total or Subtotal Left Main Occlusion: Analysis of Incidence, Clinical Features, Outcomes, and Prognostic Determinants

Although acute left main coronary artery (LMCA) occlusion is a rare clinical entity, it carries a very high mortality rate. The purposes of this study were to evaluate the effect of primary angioplasty for a severely obstructed or totally occluded LMCA, and to determine the incidence, clinical features, outcome, and prognostic determinants in this clinical setting. Between May 1993 and July 2000, a total of 740 patients with acute myocardial infarction underwent primary angioplasty in our hospital. Eighteen of 740 patients (2.4%) with a severely obstructed or totally occluded LMCA constituted the population of this study. Seventeen of 18 patients (94.4%) experienced pulmonary edema (including 14 patients in cardiogenic shock). Six patients (33.3%) sustained sudden death due to malignant ventricular tachyarrhythmias. Coronary angiography showed that there were variable grade flow of intercoronary collaterals in 12 patients (66.7%), a totally occluded LMCA in 8 patients (44.4%), an incompletely occluded LMCA in 10 patients (55.6%), and a dominant right coronary artery (RCA) in 16 patients (88.9%). Primary angioplasty of the LMCA was performed with a 72.2% procedural success rate. Four patients (22.2%) received coronary artery bypass surgery after angioplasty. Six patients (33.3%) died in the hospital. Two patients died after discharge. Ten of 18 patients (55.6%) survived in long-term follow-up (mean +/- SD, 44 +/- 14 months). Those patients who survived to be discharged had significantly higher combined coexisting incidence of intercoronary collaterals, dominant RCA, and incompletely occluded LMCA (100% vs 0.0%, p = 0.0006) than those patients who died in the hospital. Acute obstructive LMCA disease generally presented as pulmonary edema, cardiogenic shock, or sudden death. Only those who had combined coexistence of intercoronary collaterals, a dominant RCA, and an incompletely occluded LMCA could survive to be discharged. Our experience suggests that primary LMCA angioplasty is a feasible and effective procedure, and it may save lives in this clinical setting.

Implications of the absence of ST-segment elevation in lead V4R in patients who have inferior wall acute myocardial infarction with right ventricular involvement.

ST-segment elevation of > or = 1.0 mm in lead V4R has been shown to be a reliable marker of right ventricular involvement (RVI), a strong predictor of a poor outcome in patients with inferior acute myocardial infarction (IMI). However, patients with no ST-segment elevation in lead V4R despite the presence of RVI have received little attention. The study was undertaken to study the clinical features of patients with no ST-segment elevation in lead V4R despite the presence of RVI, which means false negative, as such patients have received little attention in the past. We studied 62 patients with a first IMI, who had total occlusion of the right coronary artery (RCA) proximal to the first right ventricular branch and successful reperfusion within 6 h from symptom onset, to examine the implications of the absence of ST-segment elevation in lead V4R despite the presence of RVI. A standard 12-lead electrocardiogram (ECG) and right precordial ECG (lead V4R) were recorded on admission, and three posterior chest ECGs (leads V7 to V9) were additionally recorded in 34 patients. Patients were classified according to the absence (Group 1, n = 18) or presence (Group 2, n = 44) of ST-segment elevation of > or = 1.0 mm in lead V4R on admission. Patients in Group 1 had a greater ST-segment elevation in leads V7 to V9 (2.9+/-2.4 vs. 1.4+/-3.0 mm. p < 0.05), a higher frequency of a dominant RCA (defined as the distribution score > or = 0.7) (72 vs. 11%, p < 0.001), and a higher peak creatine kinase level (3760+/-1548 vs. 2809+/-1824 mU/ml, p < 0.05) than those in Group 2. In patients with IMI caused by the occlusion of the RCA proximal to the first right ventricular branch, no ST-segment elevation in lead V4R can occur because of concomitant posterior involvement. In such patients, the incidence of RVI may be underestimated on the basis of ST-segment elevation in lead V4R.

Myocardial perfusion by contrast echocardiography. Establishment of normal pattern of intracoronary injection and safety in humans.

To establish the normal pattern and safety of echocardiographic contrast in patients with no significant obstruction of epicardial coronary arteries. 67 patients with normal coronary arteries or obstructions < 50% were selected from 277 patients who underwent coronary angiography (CA). Mean age was 56 +/- 11 years and 36 were males. At the end CA, echocardiographic contrast was selectively injected into each coronary artery. The parasternal short axis of the left ventricle (LV) was divided into six segments: anterior (A), antero-lateral (AL), postero-lateral (PL), posterior (P), infero-septal (IS) and antero-septal (AS). Anterolateral (ALPM) and posteromedial papillary muscles (PMPM) were also considered. The pattern and intensity of the appearance of the myocardial contrast was visually analyzed. The right coronary artery (RCA) was dominant in 60 patients. Contrast appearance was sudden and simultaneous in the 3 muscle layers. All segments could be contrasted after the injection in both coronary arteries. 100% of the AS, A and AL segments, 97% of the PL and 98% of the ALPM were perfused by the left coronary artery (LCA). P and IS segments were perfused by the RCA in 85% and 82%, respectively, and by a dominant LCA in 71% of the cases. The PMPM was perfused by a dominant RCA in 77% and by a dominant LCA in 86%. There were no symptoms. Intracoronary injection of the sonicated solution is a safe procedure that allows for an excellent opacification of the myocardium and can potentially be used during routine CA.

Precordial ST segment elevation in acute ischemia caused by right coronary artery occlusion.

The purpose of this study is to determine why precordial ST elevation (V1 lead) occurs during acute occlusion of the right coronary artery (RCA). Nineteen patients with vasospastic angina, in whom ergonovine administration into RCA provoked spasms, were divided into 2 groups by precordial ST change during spasms. Group I (n = 6) had precordial ST elevation; group II (n = 13) had no precordial ST elevation. A subgroup, IIA was comprised 6 patients in group II with spasms in the RCA proximal segment (segment number less than 2 of AHA coronary classification). None had left coronary dominancy. There was no difference in collateral flow during spasms. Location of spasms in group I was in the RCA proximal segment, and was significantly more proximal compared to group II. There was no difference in sigma ST in II, III, aVF between group I and II or IIA. Max ST elevation time by which duration of ischemia was estimated was significantly longer in group I than in group IIA. Three patients in group I displayed precordial ST depression before elevation, in all of whom in sigma ST in II, III, aVF was higher during precordial ST elevation than during depression. During acute occlusion in the RCA proximal segment, precordial ST elevation is caused by ischemia of the right ventricular anterior wall. Furthermore, precordial ST elevation can occur in a patient with RCA dominance, even if ischemic injury in the left ventricular infero-posterior wall increases progressively.

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)