Posterior Interventricular Groove Research Articles

Posterior right diagonal artery

There is general confusion about a branch of the posterior segment of the right coronary artery that has been referred to as 1) the lower trunk of a divided right coronary artery; 2) a posterior reflection of the right marginal artery; 3) the ramus lateralis; and 4) a posterolateral branch or a posterior descending artery. Three hundred human hearts were studied by direct observation, X-ray films, and corrosion casting. This branch of the right coronary artery arises either after the right marginal artery (in 84% of hearts) or it constitutes the continuation of this artery in the remaining 16%. We named it the posterior right diagonal artery (PRDA). It was found in 14% of 266 hearts of right dominant type. It was present in 39% when the length of the posterior descending artery (PDA) was shorter than half of the length of the posterior interventricular sulcus (PIS) and in 6% when it was longer. When the PRDA originated directly from the RCA, the RMA appeared underdeveloped; the PRDA always occupied the inferior part of the PIS and appears either as continuation of a short PDA or as a replacement for a long PDA from the point where this artery leaves the PIS to enter the posterior wall of the left ventricle. The PDRA when present serves as a bridge between the RCA and the left anterior descending artery. These findings are of practical importance for the correct interpretation of coronary arteriographies and in the field of coronary artery surgery.

Transthoracic high-frequency echocardiographic detection of atherosclerotic lesions in the descending portion of the left coronary artery.

To assess the ability of transthoracic high-frequency two-dimensional echocardiography to detect atherosclerotic lesions in the descending portion of the left coronary artery, 30 consecutive patients with suspected coronary artery disease underwent two-dimensional echocardiographic examination 24 to 96 hours before coronary angiography. The descending portion of the left coronary artery was arbitrarily divided into a mid segment (the portion of the coronary vessel embedded in the anterior interventricular sulcus) and an apical segment (the portion turning around the cardiac apex into the posterior interventricular sulcus). The mid segment was imaged in 24 and the apical segment in 25 of the 30 patients for a total of 49 out of 60 segments (82%). Comparison of the echocardiographically visualized segments with the corresponding angiographic segments indicated that a correct echocardiographic diagnosis of significant stenosis was made in 11 out of 12 segments. There were no false positive results. Thus the sensitivity and specificity of high-frequency transthoracic echocardiography in the detection of significant stenosis in the imaged segments were 92% and 100%, respectively. Compared with angiography, additional information concerning the status of the arterial wall, the presence of calcific plaques, and the cross-sectional extent of the obstructive lesions was obtained by echocardiography in eight patients.

Is it possible to rule out extensive anterior myocardial infarction in the absence of abnormal Q waves in lead I and aVL? Effect of infero-apical extension of infarction over apex.

To determine whether abnormal Q wave in lead I or aVL may be of use to estimate the size of an extensive anterior myocardial infarction, electrocardiographic and left ventriculographic findings were analyzed in 45 patients with old extensive anterior infarction. All 45 patients had a significant narrowing in the proximal segment of left anterior descending coronary artery (LAD) and severe asynergy in anterolateral segment. The patients were divided into two groups; Group I consisted of 35 cases with less involvement of the inferoapical segment and Group II of 10 cases with remarkable extension of the anterolateral infarction into the inferoapical segment due to occlusion of very long LAD supplying the anterior half of posterior interventricular groove. There were no statistical differences in the extent of anterolateral asynergy, number of abnormal Q waves in precordial leads and left ventricular ejection fraction between the two groups. While abnormal Q wave in lead I or aVL was present in 28 cases (80%) of Group I, it was observed in only 3 cases (30%) of Group II (p less than 0.01). Thus, we can't rule out extensive anterior myocardial infarction even if abnormal Q waves are absent in lead I or aVL, in which abnormal Q waves may be cancelled by loss of electromotive force of inferoapical segment due to extension of the anterior infarction over the apex in cases with extraordinarily long LAD.

Subcostal two-dimensional echocardiographic imaging of peripheral right coronary artery in Kawasaki disease.

A new two-dimensional echocardiographic technique was developed to detect peripheral right coronary aneurysms in Kawasaki disease. Because the main stem of the right coronary artery runs along the tricuspid valve ring and the posterior interventricular groove, these regions were examined for coronary aneurysms using the subcostal approach. Of 52 patients with Kawasaki disease, 14 right coronary aneurysms were visualized in eight patients. Most of the coronary aneurysms were elicited as circular or oval echo-free spaces on the right side of the right ventricle or at the area around the tricuspid valve ring. These echocardiographic features coincided well in size, shape and anatomic position with angiographic appearances. The subcostal approach could not image the normal coronary artery. In three patients whose echocardiograms showed no abnormal echo-free space, the angiographic studies proved that the right coronary arteries were intact. These results suggest that this echocardiographic technique is useful for detecting peripheral right coronary aneurysms in patients with Kawasaki disease.

Clinical significance of the double silhouette in the septal side in left anterior oblique cine left ventriculograms.

The clinical significance of a line often visible in left ventriculograms performed in the left anterior oblique position was analyzed. This line runs inside the free border of the septal silhouette, and occasionally displays a movement completely different from that of the border. Analysis of ventriculograms of 189 patients with single-vessel disease suggested that the movement of this line reflects the contractile state of the left ventricular myocardium near the posterior interventricular groove, supplied by the right coronary or circumflex artery. Evaluation of this line may be useful for a more complete assessment of left ventricular function in patients with ischemic heart disease.

Posttraumatic left ventricular myocardialinfarction and rupture in infancy

An automobile passed over the posterior thorax of an 18-month-old boy. The vertebral column contused the posterior surface of the left ventricle and the posterior interventricular sulcus; the posterior descending branch of the right coronary artery was occluded, resulting in intermittent complete atrioventricular (A-V) block. This was treated with dexamethasone, but transmural infarction occurred, followed by rupture 13 days after the accident.

Effects of Right Ventriculotomy upon Activation of the Epicardial Surface of the Canine Right Ventricle

The sequence of activation of the epicardial surface of the right ventricle has been studied before and after right ventriculotomy. Normally, the area of the right ventricle adjacent to the anterior interventricular groove is activated first, the midportion of the wall second, and the area adjacent to the posterior interventricular groove and the anterior basal area are activated last. Activation of the entire epicardial surface of the right ventricle requires 25 to 40 msec. Right ventriculotomy does not alter the sequence of activation or the time of activation of the right ventricular epicardium if the incision passes medial to the free-running Purkinje fibers or through their arborization on the right, ventricular wall. When the ventriculotomy is made lateral to the arborization of these fibers, activation of that portion of the wall lateral to the incision is delayed, and activation of the entire ventricular surface requires 42 to 52 msec. There is no electrocardiographic evidence of bundle-branch block, complete or partial, following right ventriculotomy, regardless of the location of the incision.