Enhanced detection of proximal right coronary artery stenosis with the additional analysis of right ventricular thallium-201 uptake in stress scintigrams

The value of right ventricular thallium-201 analysis in detecting proximal right coronary artery stenosis in exercise myocardial scintigraphy was analyzed in 52 patients, 27 with and 25 without proximal right coronary artery stenosis. For the detection of proximal right coronary artery stenosis, the sensitivity and specificity of thallium scintigraphic analysis were 59 and 88% for a right ventricular abnormality, 67 and 68% for a left ventricular inferior wall abnormality, and 93 and 56% for an abnormality of either. When both right and left ventricular thallium images were abnormal, all 9 patients had proximal right coronary artery stenoses, and when both were normal, 26 of 28 patients had a normal proximal right coronary artery. The sensitivity and specificity of blood pool scintigraphic variables during exercise (right ventricular ejection fraction and left ventricular inferior wall motion) were not significantly different for detection of proximal right coronary artery stenosis.Thus, the additional analysis of the right ventricle on thallium-201 stress scintigrams can improve the detection of proximal right coronary artery stenosis. When both right ventricular and left ventricular thallium scintigrams are abnormal (or normal), the ability to predict the presence (or absence) of proximal right coronary artery stenosis is very high.     

Spontaneously acquired fistula from the right coronary artery to the right ventricular cavity.

A 47 year old man developed a fistula from the right ventricular branch of the right coronary artery to the right ventricular cavity in association with distal occlusion of the main trunk of the right coronary artery. There was no clinical or electrocardiographic evidence of acute myocardial infarction.     

Isolated right ventricular infarction due to occlusion of the right ventricular branch in the absence of percutaneous coronary intervention

Isolated right ventricular myocardial infarction accounts for only 3% of all infarctions. It has previously been reported as a complication of percutaneous coronary intervention involving the right coronary artery secondary to occlusion of the right ventricular branch. In the present report, a patient is described in whom isolated right ventricular myocardial infarction developed due to occlusion of the right ventricular branch of the right coronary artery in the absence of percutaneous intervention.     

Decreased right ventricular function after coronary artery bypass grafting

Decreased right ventricular function after coronary artery bypass grafting is a common and well-known (if not well-understood) phenomenon.We prospectively evaluated right ventricular function via echocardiographic tricuspid annular motion, tricuspid annular velocity, and right ventricular strain analysis before and after coronary artery bypass grafting. We also evaluated the effect of right coronary artery disease and revascularization on post-coronary artery bypass grafting, right ventricular function, and interventricular septal motion.We performed baseline echocardiography in 250 candidates for coronary artery bypass grafting, and we repeated echocardiography in 240 of those patients 1 year after coronary artery bypass grafting. We evaluated right ventricular function via tricuspid annular motion, tricuspid annular velocity, and right ventricular strain analysis, all measured at the right ventricular free wall.Right ventricular function as evaluated by tricuspid annular motion showed a significant reduction 1 year after coronary artery bypass grafting (21.7 vs 12.1 mm; P < 0.001) compared with preoperative measurements. Right ventricular tissue velocity (14.0 vs 7.0 cm/s; P < 0.001) and right ventricular strain (20.3% vs 11.6%; P < 0.001) were also significantly reduced after coronary artery bypass grafting. Interventricular septal motion was paradoxical in 97% of the patients 1 year after coronary bypass.Right ventricular function remained depressed for as long as 1 year after coronary artery bypass grafting. These findings were independent of the state of the right coronary artery and the graft. It is likely that the interventricular septum is recruited to maintain right ventricular stroke volume after coronary artery bypass grafting.     

Effect of opening the pericardium on right ventricular hemodynamics during cardiac surgery

The impact of the pericardium on right ventricular performance in the presence of normal filling pressures was evaluated using a rapid response RVEF thermodilution pulmonary artery catheter and TEE. In eight patients with normal right coronary arteries undergoing coronary artery bypass surgery, hemodynamic measurements revealed increased right ventricular end-diastolic and end-systolic volumes with diminished RVEF after opening the pericardium. In eight additional patients with right coronary artery disease, directionally similar changes in right ventricular volume were seen. Ejection fraction, however, was unchanged possibly due to altered right ventricular compliance. Echocardiogram evaluation of right ventricular area changes in patients with compromised right coronary systems corresponded to ejection fraction determinations obtained with thermodilution technique.     

Isolated right ventricular aneurysm following right ventricular infarction

A 78-year-old man with atherosclerotic heart disease developed extensive right ventricular infarction fibrosis with aneurysm formation following right coronary artery occlusion. No symptoms of right-sided heart failure were present. Postmortem examination revealed that 40% of the right ventricle, 11% of the septum and 7% of the left ventricular free wall were infarcted due to right coronary artery occlusion. This is the first documented case of isolated aneurysm of the right ventricle following infarction and it demonstrates that even extensive right ventricular destruction may be present without symptoms.     

Anterior ST-segment elevation with right coronary artery occlusion: a unique case of isolated right ventricular infarction

Anterior ST-segment elevation is the classic electrocardiographic feature of anterior left ventricular myocardial infarction due to occlusion of the left anterior descending artery. However, anterior ST-segment elevation has also been described in patients with right coronary artery occlusion, in whom concomitant inferior ST-segment elevation is also typically present. A case of proximal right coronary artery occlusion resulting in anterior ST-segment elevation without inferior ST-segment elevation is reported in this article. It is hypothesized that the inferior left ventricular wall was protected by left-to-right collaterals, as seen on coronary angiography, with resultant isolated right ventricular infarction upon proximal right coronary artery occlusion. In conclusion, this report presents a unique case of an isolated right ventricular infarction resulting in an electrocardiographic pattern mimicking anterior-wall left ventricular infarction.     

Collateral vessel development after right ventricular infarction in the pig

Although the right coronary artery supplies both ventricles in the pig, a gradual proximal right coronary occlusion produces infarction in the left ventricle, whereas the right ventricle is usually spared. This study evaluates the influence of right ventricular hypertension and hypertrophy (RVHH) on the occurrence of right ventricular infarction and the difference in the rate and extent of collateral vessel development after gradual right coronary occlusion in pigs with (RVHH group) and without (control group) increased right ventricular pressure and mass. Right ventricular hypertension and hypertrophy were induced by pulmonary arterial banding which raised right ventricular systolic pressure from 24 to 74 mm Hg and doubled right ventricular mass in 4 weeks. Right coronary occlusion was produced with an ameroid constrictor in 24 control group pigs and 15 RVHH pigs. Serial selective coronary cineangiograms on days 4, 8, 14, 21 and 28 after ameroid constrictor placement showed no difference in first appearance of collateralization to the occluded right coronary artery. Total collateralization, which was present in all pigs studied in the control group by days 21 and 28, was present in only 57 percent of the RVHH group at the same time. Although left ventricular infarction occurred in all animals in both groups, right ventricular infarction was not found in the control group but was seen in 80 percent of the RVHH group. There was no correlation between the degree of collateralization seen and the size of the right ventricular infarction found. Experimentally induced right ventricular hypertrophy and hypertension make the right ventricle susceptible to infarction and impeded total collateral filling of the occluded right coronary artery in some of the animals studied.     

Thallium-201 stress redistribution abnormalities of the right ventricle: A manifestation of proximal right coronary artery stenosis

Thallium imaging in conjunction with electrocardiographic stress testing has become a widely utllized method for evaluating the presence and location of coronary artery disease. The literature has emphasized the appearance of the left ventricle with little mention of the right ventricle. This report presents the initial demonstration of abnormal right ventricular myocardial radionuclide visualization due to right coronary artery stenosis, as exemplified in two patients. In both patients a perfusion defect was documented in the free wall of the right ventricle with early redistribution imaging showing reversibility of these defects. Both patients were found to have proximal stenosis of the right coronary artery at cardiac catheterization. Thereby, the appearance of the free right ventricular wall on thallium imaging may provide useful additional information regarding presence and location of right coronary artery stenosis.     

Nondominant right coronary artery occlusion presenting with isolated right ventricular infarction and ventricular fibrillation

It is generally believed that serious complications are unlikely in a myocardial infarction resulting from occlusion of a nondominant right coronary artery. A case of isolated right ventricular infarction caused by total occlusion of a nondominant right coronary artery complicated by two episodes of ventricular fibrillation is presented.     

Pressure-flow relations in the pulmonary artery during myocardial ischaemia: implications for right ventricular function in coronary disease

Because exercise induced pulmonary hypertension may disturb optimal coupling between the right ventricle and pulmonary artery in coronary artery disease, high fidelity pulmonary artery and right ventricular pressure and electromagnetic pulmonary artery flow velocity data were recorded at rest and during supine exercise in 10 control subjects free of detectable cardiovascular disease and in 11 patients with coronary artery disease. The pulmonary artery impedance and power spectra were calculated from Fourier analysis of pressure and flow waveforms. Total hydraulic power expended per unit of forward flow was computed as an index of right ventricular-pulmonary artery coupling. In coronary artery disease exercise produced substantial increases in pulmonary artery pressure, pulmonary artery characteristic impedance, and total power per unit flow. These changes did not occur in control subjects. Despite a significant exercise increase in right ventricular end diastolic pressure and peak right ventricular dP/dt, and independent of the presence of right coronary artery involvement, the right ventricular stroke output response during exercise was significantly blunted in the coronary artery disease patients. Pulmonary vascular resistance was unchanged by exercise in either group. Exercise induced ischaemia presents an increased pulsatile hydraulic load to the right ventricle. Increased pulmonary artery input impedance impairs the hydraulic efficiency of right ventricular-pulmonary artery coupling and may contribute to the limitation of right ventricular ejection performance in coronary artery disease.     

Aberrant right ventricular branch of right coronary artery with mitral valve prolapse

A 37-year-old man presented with a three-week history of chest pain. Transthoracic echocardiography demonstrated a mitral valve prolapse and mild mitral insufficiency. Coronary angiography showed normal left main, circumflex, left anterior descending and right coronary arteries; however, the right ventricular branch of the right coronary artery had a separate ostium. Concomitant congenital heart abnormalities have been observed with coronary artery anomalies. Primary congenital coronary and valvular anomalies may have genetic heredity. In the present case, mitral valve prolapse was accompanied by a right ventricular coronary artery origin anomaly which, to the best of our knowledge, is the first report in the literature in which both anomalies presented together.     

Primary angioplasty for isolated right ventricular infarction.

We describe a case of isolated right ventricular infarction that has rarely been diagnosed antemortem. Electrocardiogram showed ST segment elevation in left precordial chest, right precordial chest, and inferior leads, which mimicked those of anterior and inferior left ventricular infarction. Coronary angiography revealed that culprit lesion was totally occluded right coronary artery. Infarcted artery was nondominant right coronary artery with branches supplying only right ventricular wall. Restoration of coronary blood flow was obtained by primary stenting and resulted in prompt ST segment normalization in all leads. Despite extensive right ventricular wall motion abnormality, subsequent right ventricular dysfunction was not observed.     

Serial right ventricular thallium-201 imaging after exercise: Relation to anatomy of the right coronary artery

The relation of the appearance of the right ventricle on serium thallium-201 myocardial imaging to coronary artery anatomy was examined in 88 consecutive patients undergoing exercise thallium-201 testing and coronary angiography for the evaluation of chest pain. Transient defects in the right ventricle were found in 8 patients. All had high grade (≥ 90 %) stenosis of the proximal right coronary artery. Nonvisualization of right ventricular (RV) activity occurred in 10 patients. Nine of the 10 (90%) had significant (>- 50% stenosis) disease of the proximal right coronary artery and 7 (70%) had high grade stenosis. The right ventricle appeared normal in 70 patients. Twenty-nine (41 %) of these patients had significant proximal right coronary artery disease. Right ventricular appearance was not affected by the presence or absence of disease of the left anterior descending or left circumflex artery or by the appearance of the left ventricle.

Thus, with serial RV thallium-201 myocardial imaging after exercise, we found that (1) RV transient defects suggest the presence of high grade proximal right coronary artery stenosis, (2) nonvisualization of RV activity also predicts significant proximal right coronary disease, and (3) the right ventricle frequently appears normal despite proximal right coronary artery disease and therefore this finding does not exclude such disease.     

右冠状动脉与左回旋支病变致右室梗死32例临床对比分析

目的探讨右冠脉与左回旋支病变致右室梗死冠脉病变特点及临床特征。方法筛选我院2007年10月至2013年11月入院的32例右室心肌梗死患者,根据梗死相关动脉分为右冠组（25例）和左回旋支组（7例）。收集其临床资料及冠脉造影结果,进行分析总结。结果右冠组多为近段病变,左回旋支组多为中远段病变。右冠病变致右室梗死,其缓慢性心律失常发生率高于左回旋支病变（P〈0．05）。结论右室梗死多见于中青年患者,多为右冠脉近端病变所致。右冠脉病变恶性缓慢型心律失常发生率高于左回旋支病变,且预后差于左回旋支病变。     

Incidence of exertional right ventricular wall motion abnormalities in patients with coronary artery disease

To evaluate the role of analysis of right ventricular function with exercise in patients with presumed coronary artery disease referred for radionuclide ventriculography, the records of 55 patients referred to our laboratory over a 19-month period were reviewed. All underwent rest and exercise first-pass radionuclide stress testing and cardiac catheterization within a period of four months. Three groups were identified: (1) patients with normal exercise right ventricular function (n = 24); (2) patients with exercise-induced right ventricular regional wall motion abnormalities (n = 15); and, (3) patients with abnormal resting right ventricular function without new exercise abnormalities (n = 16). Patients in each group were similar in age, sex, baseline left ventricular function, medication usage, and indication for study. The incidence of right coronary artery disease was identical in the three groups, as was the incidence of left ventricular functional abnormalities with exercise. Patients with proximal right coronary artery disease were more likely to have reduced left ventricular ejection fraction and more extensive coronary artery disease than those without disease at this site. We conclude that: (1) analysis of rest and exercise right ventricular function does not allow prediction of coronary anatomy in an unselected group of patients; (2) normal right ventricular function with exercise is compatible with extensive coronary artery disease, including proximal right coronary artery disease; and (3) abnormal exercise right ventricular function may be due to exertional left ventricular dysfunction in the absence of proximal right coronary artery disease.     

Precordial ST-segment elevation caused by right coronary artery occlusion

Among 57 consecutive patients undergoing percutaneous transluminal coronary angioplasty (PTCA) of the right coronary artery, eight patients showed precordial ST-segment elevation in leads V1-3 during the procedure. The mechanism of this ST elevation was investigated reviewing the coronary angiographic findings. All patients had angina pectoris, but none had evidence of myocardial infarction. The balloon inflation time was limited to 60 sec, and 12 lead electrocardiograms were recorded every 15 sec. In the eight patients who had precordial ST-segment elevation, six had the anatomically dominant right coronary artery, and two had proportioned (balanced) left and right coronary arteries. Six patients, however, had functionally dominant left coronary arteries because of good collaterals supplying the right coronary artery from the left coronary artery. Thus, functionally, six had the dominant left coronary artery, one had proportioned coronary supply, and only one had the dominant right coronary artery. In all eight patients, the most proximal portion of the right coronary artery was occluded during PTCA, obstructing both the conus branches and the right ventricular branches. This often induced precordial ST-segment elevation in cases with the functionally dominant left or proportioned coronary artery. This ST-segment elevation seemed to represent right ventricular ischemia, as the inferior wall was protected from ischemia by good collaterals. However, precordial ST-segment elevation was rare in the functionally dominant right coronary artery even when the most proximal portion of the right coronary artery was occluded. This fact seemed due to masking of electrocardiographic manifestations of right ventricular ischemia by the dominant electrical forces of inferior wall ischemia.     

Myocardial bridging confined to the right ventricular branch of the right coronary artery in a patient with severe pulmonary hypertension

Although myocardial bridges are mostly confined to the left anterior descending coronary artery, several cases of right coronary artery myocardial bridging have been reported in the literature. In the current case report, we present a 65-year-old female with a well-functioning mechanical mitral valve prosthesis, severe pulmonary hypertension and right ventricle wall motion abnormality in whom diagnostic angiography revealed myocardial bridging confined to the right ventricular branch of the right coronary artery.     

Single coronary artery with the right coronary artery arising from the first septal perforator

A 50-year-old woman with chest pain and an exercise thallium-201 scintigram positive for focal ischemia was found on coronary arteriography to have a heretofore unreported variant of single left coronary artery with the right coronary artery originating as a branch from the first septal perforator. Proximally, the aberrent vessel coursed through the ventricular septum at the level of the right ventricular outflow tract. A conus artery was absent and this is a possible basis for the focal basal ventricular ischemia and the patient's symptoms.     

Symptomatic right ventricular ischemia secondary to a critical stenosis in a nondominant right coronary artery

Stable angina pectoris owing to isolated right ventricular ischemia from a critical stenosis in a nondominant right coronary artery is a rare entity and documentation of isolated right ventricular ischemia even rarer. We present a case of isolated right ventricular ischemia documented by fractional flow reserve (FFR) and resolution of symptoms after percutaneous coronary intervention. © 2012 Wiley Periodicals, Inc.