Cardiac Troponin Composition Characterization after Non ST-Elevation Myocardial Infarction: Relation with Culprit Artery, Ischemic Time Window, and Severity of Injury.

BACKGROUND: Troponin composition characterization has been implicated as a next step to differentiate among non-ST elevation myocardial infarction (NSTEMI) patients and improve distinction from other conditions with troponin release. We therefore studied coronary and peripheral troponin compositions in relation to clinical variables of NSTEMI patients. METHODS: Samples were obtained from the great cardiac vein (GCV), coronary sinus (CS), and peripheral circulation of 45 patients with NSTEMI. We measured total cTnI concentrations, and assessed both complex cTnI (binary cTnIC + all ternary cTnTIC forms), and large-size cTnTIC (full-size and partially truncated cTnTIC). Troponin compositions were studied in relation to culprit vessel localization (left anterior descending artery [LAD] or non-LAD), ischemic time window, and peak CK-MB value. RESULTS: Sampling occurred at a median of 25 hours after symptom onset. Of total peripheral cTnI, a median of 87[78-100]% consisted of complex cTnI; and 9[6-15]% was large-size cTnTIC. All concentrations (total, complex cTnI, and large-size cTnTIC) were significantly higher in the CS than in peripheral samples (P < 0.001). For LAD culprit patients, GCV concentrations were all significantly higher; in non-LAD culprit patients, CS concentrations were higher. Proportionally, more large-size cTnTIC was present in the earliest sampled patients and in those with the highest CK-MB peaks. CONCLUSIONS: In coronary veins draining the infarct area, concentrations of both full-size and degraded troponin were higher than in the peripheral circulation. This finding, and the observed associations of troponin composition with the ischemic time window and the extent of sustained injury may contribute to future characterization of different disease states among NSTEMI patients.

Variations and angulation of the coronary sinus tributaries: Implications for left ventricular pacing.

BACKGROUND: Variations of the coronary sinus tributaries might result in difficulties in left ventricle electrode insertion during cardiac resynchronizing therapy. Morphometric features of tributaries, especially angulation of the coronary sinus tributaries, are crucial for coronary sinus procedures. METHODS: This study was carried out on 200 formaldehyde-fixed human hearts (22.0% females, mean age of 48.7 ± 15.6 years). RESULTS: The inferolateral aspect of the left ventricle was accessible from the coronary venous tree in 77.0% (in 35% from one, 29% from two, and 13.0% from three tributaries). The middle cardiac vein was present in all cases, with a diameter of 1.8 ± 0.5 mm, cannulation distance of 5.3 ± 3.2 mm, and angle of 82.0 ± 12.8°. The inferolateral vein of the left ventricle varied greatly in number: single in 63.5%, multiple in 30.5%. The ostium diameter for a single vein was 1.3 ± 0.5 mm, cannulation distance was 21.1 ± 9.8 mm, and the angle was 98.1 ± 13.5°. The left marginal vein was present in 39.5% with an ostium diameter of 0.9 ± 0.5 mm, cannulation distance of 46.0 ± 12.0 mm, and angle of 92.0 ± 13.4°. Finally, the oblique vein of the left atrium was present in 71.0% with a diameter of 1.3 ± 0.8 mm, cannulation distance of 27.2 ± 9.4 mm, and angle of 136.8 ± 16.6°. CONCLUSIONS: This study shows the clinically relevant morphometric characteristic of coronary sinus tributaries. The middle cardiac vein is the most constant among coronary veins. However, it is usually not suitable for left ventricular pacing. The inferolateral vein of the left ventricle is highly variable in number, but its morphology makes it a suitable target for left ventricular lead placement.

[Surgery in Elderly Patient for Coronary Arteriovenous Fistula and Giant Coronary Artery Aneurysm Associated with Cardiac Failure;Report of a Case].

An 82-year-old woman visited the hospital with the chief complaint of dyspnea on light exertion. Computed tomography (CT) showed a coronary artery aneurysm and coronary arteriovenous fistulas. The pulmouary flow/systemic flow (Qp/Qs) ratio was 1.4, and the left-to-right shunt rate was 31%.Two anomalous vessels were identified. One arose from the right coronary artery, formed an aneurysm, and drained into the coronary sinus, while the other originated from the distal circumflex branch and drained directly into the coronary sinus. The aneurysm measured 50×45 mm. The anomalous vessel from the right coronary artery was ligated at the sites of flow from the right coronary artery and at the site of drainage into the coronary sinus. The circumflex artery was ligated at the last branch and at the site of drainage into the coronary sinus. The aneurysm was incised and the vessel flowing into the aneurysm was sutured closed. Postoperative CT showed no anomalous blood vessel and the circumflex artery was visualized up to the last branch.

A rare variation of the hemiazygos vein draining into the persistent left superior vena cava.

During an educational dissection of a 72-year-old Chinese male cadaver, the hemiazygos vein (HAV) coursing the left side that drains into the persistent left superior vena cava was observed. The HAV was formed at the junction of the 9th to 11th right posterior intercostal veins, right subcostal vein, 5th to 11th left posterior intercostal veins, and left subcostal vein; it then ascended posteriorly to the thoracic aorta. After collecting the accessory hemiazygos vein, it crossed over the aorta and the pedicle of the left lung via the hemiazygos arch, then converged with a communicative branch (vein of Marshall) that emerged from the left brachiocephalic vein to form the persistent left superior vena cava and entered the pericardium at the level of the sixth thoracic vertebra. Upon opening the pericardium of our cadaver, the persistent left superior vena cava was found to drain directly into the significantly dilated coronary sinus at the level of the eighth thoracic vertebra. The azygos vein was formed by the union of the first to eighth right posterior intercostal veins and appeared to be finer and shorter than the HAV. The persistent left superior vena cava might be the result of incomplete degeneration of the left posterior cardinal vein. Knowledge of such variations could be of great value to surgeons placing peripherally inserted central catheters because incorrect placement of the azygos venous system can be detrimental to the patient. In addition, during heart surgery, awareness of such variations may prevent major complications, such as hemorrhage or damage to vascular structures, and possibly also provide new insights and perspectives to cardiovascular surgeries.

Recapitulation of developmental mechanisms to revascularize the ischemic heart.

Restoring blood flow after myocardial infarction (MI) is essential for survival of existing and newly regenerated tissue. Endogenous vascular repair processes are deployed following injury but are poorly understood. We sought to determine whether developmental mechanisms of coronary vessel formation are intrinsically reactivated in the adult mouse after MI. Using pulse-chase genetic lineage tracing, we establish that de novo vessel formation constitutes a substantial component of the neovascular response, with apparent cellular contributions from the endocardium and coronary sinus. The adult heart reverts to its former hypertrabeculated state and repeats the process of compaction, which may facilitate endocardium-derived neovascularization. The capacity for angiogenic sprouting of the coronary sinus vein, the adult derivative of the sinus venosus, may also reflect its embryonic origin. The quiescent epicardium is reactivated and, while direct cellular contribution to new vessels is minimal, it supports the directional expansion of the neovessel network toward the infarcted myocardium. Thymosin ß4, a peptide with roles in vascular development, was required for endocardial compaction, epicardial vessel expansion, and smooth muscle cell recruitment. Insight into pathways that regulate endogenous vascular repair, drawing on comparisons with development, may reveal novel targets for therapeutically enhancing neovascularization.

Transcatheter coiling of saphenous vein graft to coronary sinus after coronary artery bypass surgery: a case report.

Unintended graft anastamosis to coronary veins after coronary artery bypass surgery is an extraordinarily rare complication. The following case report involves the unintended grafting of a saphenous vein to the coronary sinus rather than the intended arterial target during coronary artery bypass surgery, and the subsequent physiologic consequences and clinical management.

Reduced antegrade flow in the coronary sinus is a predictor of coronary artery stenosis in hypertensive patients.

OBJECTIVES: The purpose of this study was to evaluate the feasibility of assessing blood flow in the coronary sinus by transthoracic Doppler echocardiography for detecting coronary artery stenosis in hypertensive patients. METHODS: Flow in the coronary sinus was studied in 105 participants who all had undergone coronary angiography: 35 nonhypertensive patients, 34 hypertensive patients without coronary artery disease (CAD), and 36 hypertensive patients with CAD. The antegrade phase of flow in the coronary sinus was analyzed and compared among the groups. Multivariate analysis for blood flow and coronary artery stenosis was done. RESULTS: Compared with the nonhypertensive patients, the hypertensive patients without CAD had significantly higher blood flow (9.36 ± 5.94 vs 5.84 ± 2.91 mL/stroke and 584.45 ± 177.32 vs 327.68 ± 125.48 mL/min, respectively; P < .001) in the coronary sinus. Compared with the hypertensive patients without CAD, those with CAD had significantly lower blood flow (5.18 ± 0.72 vs 9.36 ± 5.94 mL/stroke and 352.51 ± 156.18 vs 584.45 ± 177.32 mL/min; P < .001) and a lower velocity time integral (13.14 ± 2.51 vs 19.85 ± 4.89 cm; P < .01). Stepwise multiple regression analysis indicated that the coronary sinus diameter, velocity time integral, and heart rate significantly correlated with the blood flow per minute in the coronary sinus in each group, and the flow per minute was the independent determinant of the percent stenosis diameter. The sensitivity, specificity, and accuracy for the prediction of severe stenosis (>70%) in the left coronary artery were 91.07%, 87.76%, and 88.49% for blood flow of less than 220 mL/min in the coronary sinus. CONCLUSIONS: Transthoracic Doppler echocardiography can effectively depict blood flow changes in the coronary sinus, and reduced antegrade flow is a sensitive and specific predictor of coronary artery stenosis in hypertensive patients.

Cerebral and myocardial blood flow responses to hypercapnia and hypoxia in humans.

In humans, cerebrovascular responses to alterations in arterial Pco(2) and Po(2) are well documented. However, few studies have investigated human coronary vascular responses to alterations in blood gases. This study investigated the extent to which the cerebral and coronary vasculatures differ in their responses to euoxic hypercapnia and isocapnic hypoxia in healthy volunteers. Participants (n = 15) were tested at rest on two occasions. On the first visit, middle cerebral artery blood velocity (V(P)) was assessed using transcranial Doppler ultrasound. On the second visit, coronary sinus blood flow (CSBF) was measured using cardiac MRI. For comparison with V(P), CSBF was normalized to the rate pressure product [an index of myocardial oxygen consumption; normalized (n)CSBF]. Both testing sessions began with 5 min of euoxic [end-tidal Po(2) (Pet(O(2))) = 88 Torr] isocapnia [end-tidal Pco(2) (Pet(CO(2))) = +1 Torr above resting values]. Pet(O(2)) was next held at 88 Torr, and Pet(CO(2)) was increased to 40 and 45 Torr in 5-min increments. Participants were then returned to euoxic isocapnia for 5 min, after which Pet(O(2)) was decreased from 88 to 60, 52 and 45 Torr in 5-min decrements. Changes in V(P) and nCSBF were normalized to isocapnic euoxic conditions and indexed against Pet(CO(2)) and arterial oxyhemoglobin saturation. The V(P) gain for euoxic hypercapnia (%/Torr) was significantly higher than nCSBF (P = 0.030). Conversely, the V(P) gain for isocapnic hypoxia (%/%desaturation) was not different from nCSBF (P = 0.518). These findings demonstrate, compared with coronary circulation, that the cerebral circulation is more sensitive to hypercapnia but similarly sensitive to hypoxia.