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PubMed1979

Evidence from a nonrandomized study that coronary surgery prolongs survival in patients with two-vessel coronary disease.

Within the larger Seattle Heart Watch arteriography registry, surgically treated patients non randomly selected for direct myocardial revascularization were matched to medically treated patients such that each of the 287 pairs was identical in seven variables (ejection fraction, ventricular arrhythmia on resting electrocardiogram, age, heart murmur, stenosis of left main coronary artery greater than or equal to 50%, number of vessels with stenosis greater than or equal to 70%, and use of diuretics) previously demonstrated to be independently predictive of survival. Actuarial survival analyses based on cardiovascular deaths (average follow-up 3.5 years) indicate improved survival for the entire surgical matched pair cohort (p = 0.008) and for the surgically treated subgroup with two-vessel disease (p = 0.0002) when compared to the medical cohort. These results were confirmed by examination of the entire arteriography registry (n = 1524) in which these seven variables were known, using Cox's model for survival analysis. This multivariate, statistical technique indicated that the surgical mode of therapy was significantly predictive of improved survival in surgically treated patients for the entire registry (p = 0.008) and for the subgroup with two-vessel disease (p = 0.0005).

Adult↗
PubMed1989

Clinical significance of Aqrs, At and ventricular gradient in single vessel coronary artery diseases.

Deflection area vectors of QRS (Aqrs) and T (At) and ventricular gradient (G) calculated from vectorcardiographic leads were compared in single vessel coronary artery diseases divided into subgroups of normokinetic, hypokinetic and akinetic by left ventriculography. In the LAD group, Aqrs shifted posteriorly, At were smaller and shifted to the right and G were smaller and shifted posteriorly or to the right. In the RCA group, Aqrs were smaller and shifted upwards, At shifted upwards and G were smaller and shifted upwards. In the LCx group, Aqrs shifted upwards, At shifted anteriorly and upwards and G were smaller and shifted upwards. Decreased magnitude and directional change of G reflect the severity and location of myocardial damage.

Adult↗
PubMed1993

Comparison of regional myocardial blood flow in syndrome X and one-vessel coronary artery disease.

Myocardial blood flow (MBF) was measured using continuous inhalation of oxygen-15-labeled carbon dioxide, and positron emission tomography before and after intravenous dipyridamole in 13 patients with syndrome X (angina pectoris, angiographically normal coronary arteries, positive exercise test and negative ergonovine test), 7 healthy subjects and 8 patients with 1-vessel coronary artery disease (CAD). In patients with syndrome X, baseline MBF was greater than in healthy subjects and patients with CAD (1.24 +/- 0.27 vs 0.87 +/- 0.07 and 1.03 +/- 0.23 ml/g/min, respectively; p < 0.05), and more heterogeneous (34 +/- 7 vs 26 +/- 5 and 25 +/- 6, respectively; p < 0.05) as assessed by the coefficient of variation among myocardial regions < or = 2.3 cm3. After dipyridamole, MBF in patients with syndrome X was similar to that in healthy subjects (2.95 +/- 0.75 vs 3.40 +/- 0.82 ml/g/min; p = NS) and greater than in patients with CAD (1.78 +/- 0.76 ml/g/min; p < 0.05). However in patients with both syndrome X and CAD, MBF was more heterogeneous than in healthy subjects (48 +/- 12 and 48 +/- 11, respectively, vs 30 +/- 7; p < 0.01). Thus, in patients with syndrome X, MBF is abnormally heterogeneous both at baseline and after dipyridamole. These findings are compatible with the presence of dynamic alterations of small coronary arteries. Because these alterations appear to be very sparse within the myocardium, they can be undetected when myocardial perfusion, function and metabolism are assessed using conventional methods that are unable to detect small myocardial regions.

Adult↗
PubMed1993

Which angiographic variable best describes functional status 6 months after successful single-vessel coronary balloon angioplasty?

OBJECTIVES: The aim of this study was to determine which quantitative angiographic variable best describes functional status 6 months after coronary balloon angioplasty. BACKGROUND: Several angiographic restenosis criteria have been developed. These can be divided into those that describe the change in lesion severity and those that merely describe lesion severity at follow-up angiography. The functional significance of these criteria is unknown. METHODS: We studied 350 patients with single-vessel coronary artery disease who underwent a single-site balloon dilation. Sensitivity and specificity curves were constructed for the prediction of anginal status and exercise electrocardiography of four quantitative angiographic variables that describe restenosis. The point of highest diagnostic accuracy for the variables was determined at the intersection of the sensitivity and specificity curves. Results of exercise electrocardiography were considered indicative for ischemia 6 months after angioplasty if horizontal or downsloping ST segment depression > or = 1 mm occurred. RESULTS: The points of highest diagnostic accuracy of the angiographic variables were similar for both anginal status and exercise electrocardiography: 1.45 and 1.46 mm for the minimal lumen diameter measurements, 45.5% and 46.5% for the percent diameter stenosis measurements at follow-up, -0.30 and -0.32 mm for change in minimal lumen diameter and -10% and -10% for the change in percent diameter stenosis at follow-up. CONCLUSIONS: Angiographic variables reflecting a change in lesion severity at follow-up angiography were only slightly less accurate than variables that describe lesion severity at follow-up. The large study group and the fact that the same optimal values for diagnostic accuracy of the various quantitative angiographic variables were obtained for the prediction of two different markers of ischemia suggests that these values reflect the lesion severity or increase in lesion severity in major epicardial vessels at which coronary flow reserve is unable to meet myocardial demands.

Angina Pectoris↗
PubMed1994

Prognostic value of left ventricular mass in uncomplicated acute myocardial infarction and one-vessel coronary artery disease.

This study assesses the relative prognostic value of increased left ventricular (LV) mass compared with residual ischemic myocardium and angiographic characteristics of the diseased vessel in 76 patients with uncomplicated acute myocardial infarction associated with 1-vessel coronary artery disease (CAD). All patients underwent symptom-limited treadmill exercise testing, resting and dipyridamole echocardiography and coronary angiography before discharge, and were followed-up for 32 +/- 6 months. LV measurements were obtained in diastole according to the Penn convention. Measurements of LV mass were divided by body surface area to obtain LV mass index. A cut-off value of 135 g/m2 body surface area for men and 112 g/m2 for women was prospectively selected. The individual effects of clinical, stress testing and angiographic variables were evaluated by using the Cox regression model. Echocardiographic LV mass index was increased in 43 patients and normal in 33. There was no intergroup difference with respect to baseline clinical and angiographic variables, ejection fraction and prevalence of stress-induced ischemia. During follow-up there were 23 cardiac events in the 43 patients with increased LV mass index and only 5 in the 33 with normal LV mass index (p < 0.001). No patient died or had nonfatal reinfarction among patients with normal LV mass. Cox survival analysis identified an increased LV mass index as the only independent predictor of cardiac events (chi-square = 7.9; p < 0.005; RR = 5.4). Thus, these data suggest that LV mass is an important independent risk factor in patients with uncomplicated acute myocardial infarction associated with 1-vessel CAD.

Adult↗
PubMed1978

[Comparative study of coronary vessel diameters in intravital and postmortal angiograms (author's transl)].

In a total of 21 mongrel dogs a comparison between intravital and postmortal coronary arteriograms was made so as to establish the difference in vessel diameter. Fresh postmortal hearts injected in situ showed an average increase in coronary vessel diameter of approx. 6 per cent. Examinations of 24 hour postmortal hearts which were removed from the animals showed a vessel diameter increase of barely 20 per cent in the mean. These 20 per cent correspond fairly well with literature information about the maximal widening of coronary vessels with nitroglycerin. Nerves which are still functioning, and humoral substances which may influence the still living muscle in vessel walls are supposed to be the reason for the smaller increase in fresh postmortal in situ illustrated coronary arteries. It must be stressed, that the measured differences between intravital and postmortal coronary artery diameters can only be representative of wall sections free of arterioslcerosis.

Animals↗
PubMedDate not supplied

Sinus node dysfunction in acute inferior myocardial infarction. Role of sinus node artery and clinical course in patients with one-vessel coronary artery disease.

To determine the role of the sinus node artery and the clinical course in postmyocardial infarction sinus node dysfunction, 27 patients with acute inferior myocardial infarction and single-vessel coronary artery disease were studied. In 13 patients (group 1) the infarct-related coronary artery was occluded proximally and in 14 (group 2) distally to the site of origin of the sinus node artery. At electrophysiology, performed 10 +/- 3 days from the acute event, basal and intrinsic heart rate were lower in group 1 compared to group 2 patients (54 +/- 4.8 vs. 69 +/- 7 beats/min, p = 0.001, and 66 +/- 7 vs. 76 +/- 8 beats/min, p = 0.006, respectively) while basal and intrinsic corrected sinus node recovery times were prolonged in group 1 compared to group 2 patients (585 +/- 49.3 vs. 324 +/- 61.3 ms, p = 0.0001, and 601 +/- 39.1 vs. 335 +/- 73 ms, p = 0.0001). During a 6-month follow-up no episodes of dizziness, syncope or angina were reported. Moreover, at the end of follow-up resting heart rate (70 +/- 11 vs. 73 +/- 7 beats/min, nonsignificant), maximal exercise heart rate (166 +/- 19 vs. 170 +/- 23 beats/min, nonsignificant), and exercise time (491 +/- 120 vs. 480 +/- 155 s, nonsignificant) were similar between the two groups and no exercise-induced ischemic ST segment depression was observed. Sinus node dysfunction in patients with inferior myocardial infarction and one-vessel disease is related to the occlusion of the infarct-related coronary artery proximal to the site of origin of the sinus node artery and is not associated with increased cardiovascular morbidity in the first 6 months from the acute event.

Adult↗
PubMed1988

[Sudden cardiac death and arrhythmia profile in patients with single-vessel coronary disease].

214 patients with single vessel disease (high grade stenosis greater than or equal to 75% or occlusion of the LAD, RCA or LCX) were followed for 1-78 months, average 51 months. Incidence of sudden death was studied in relation to coronary artery lesions, left ventricular wall motion and ventricular arrhythmias found during ambulatory ECG monitoring at the time of angiography. Incidence of sudden death was 11.1% (16/144) in LAD, 7.3% (4/55) in RCA and 6.7% (1/15) in LCX lesions. Coronary artery occlusion was associated with a significantly higher incidence of sudden death (14.6%, 18/123) than high-grade stenosis (3.3%, 3/91) (p less than 0.05). The risk of sudden death increased markedly in patients with complex arrhythmias and an occluded LAD or RCA (21.0%, 8/38; 18.2%, 2/11) compared to patients without complex arrhythmias (14.7%, 5/34; 5.5%, 1/18) (p = ns). Only one patient (1/15, 6.7%) with an isolated LCX lesion died suddenly. Our data show that the incidence of sudden death over 51 months is relatively low in patients with single vessel disease. However, LAD occlusion or RCA lesion with akinetic left ventricular areas and complex arrhythmias are independent predictors of sudden death.

Adult↗
PubMed1997

Effect of significant two-vessel versus one-vessel coronary artery stenosis on myocardial contrast defects observed with intermittent harmonic imaging after intravenous contrast injection during dobutamine stress echocardiography.

OBJECTIVES: We sought to determine the effect of multivessel as opposed to single-vessel coronary artery stenosis on myocardial contrast defects observed with intermittent harmonic imaging and intravenous perfluorocarbon-exposed sonicated dextrose albumin contrast injection. BACKGROUND: Intermittent harmonic imaging has permitted the detection of myocardial perfusion abnormalities with an intravenous ultrasound contrast agent. The effect of multivessel disease on inducibility of these perfusion abnormalities is unknown. METHODS: In 10 dogs, intravenous injections of contrast agent were given at rest and during dobutamine stress echocardiography when a single coronary artery stenosis was present (> or = 50% diameter by quantitative angiography) and again when a second stenosis (range 44% to 92% diameter) was present in the vessel supplying the adjacent perfusion bed. The peak myocardial contrast was visually and quantitatively assessed in the mid and lateral regions of the perfusion bed of the first stenosis (original stenosis zone) in the presence of one- and two-vessel stenosis. RESULTS: Peak myocardial contrast defects in both the mid and lateral segments of the original stenosis zone during dobutamine stress echocardiography was significantly lower when two-vessel stenosis was present (p = 0.015), especially in the lateral segment. The spatial extent of the perfusion defect in the original stenosis zone risk area increased significantly when two-vessel stenosis was present, and correlated closely with actual risk area (r = 0.99). Previous total occlusion followed by reperfusion of the vessel supplying the original stenosis zone significantly increased the amount of collateral activity between perfusion beds. CONCLUSIONS: Collateral flow limits the spatial extent of inducible ischemia within the risk area of single-vessel stenosis. Restoring blood flow to one perfusion bed reduces the extent of a perfusion abnormality that can be induced in an adjacent stenosed bed.

Animals↗
PubMed1997

Factors affecting internal mammary artery graft survival: how is competitive flow from a patent native coronary vessel a risk factor?

Recent studies have suggested that competitive flow is an important factor in early internal mammary artery (IMA) graft failure. Flow competition from minimally diseased native coronary vessels has been implicated in the failure of IMA grafts, but does not seem to affect saphenous vein grafts (SVG). The objective of this study was to determine the effects of competitive flow on SVG and IMA grafts and to compare the patterns of flow dynamics and pressure on proximal and distal grafts to the left anterior descending (LAD) artery; factors that may be involved in graft failure. Twelve mongrel dogs underwent coronary artery bypass grafting using IMAs and a SVG to an open LAD artery. The right IMA (PIMA) and the SVG were anastomosed in the proximal LAD and the left IMA (DIMA) was anastomosed at a more distal location. The procedure was performed through a left thoracotomy, using an "off pump" technique. Graft flows were measured isolated and in competition. The IMAs and SVG provided flow levels similar to the native LAD when each one was the sole inflow to the LAD. During competitive flow conditions, total and diastolic SVG flows were reduced 54.4 and 50.5%, respectively (P < 0.05). Total and diastolic PIMA and DIMA flows were reduced more drastically (68.6-73.3 and 69.5-68.1%, respectively; P < 0.05). The DIMA had better preservation of diastolic flow compared to PIMA. A delay in the pressure wave was noted in the isolated IMAs, but not in the SVG. This pattern of flow disappeared during competition due to the large, systolic retrograde flow up the IMA grafts. In conclusion, IMAs compared to the SVG are longer and narrower conduits with lower levels of flow during competition. Low levels of flow and oscillating flow (retrograde/ antegrade) may be poorly tolerated by the IMA endothelium and may be factorial to graft failure. These data suggest that a more distal placement of the IMA graft may be protective to the arterial graft under competitive flow conditions.

Animals↗
PubMed1985

[Myocardial infarction with normal coronary vessels in young subjects. Apropos of 2 cases with an interval of 2 months in 2 brothers aged 32 and 34].

The authors report 2 cases of myocardial infarction with normal coronary arteries occurring at an interval of 2 months in 2 brothers aged 32 and 34. Following an episode of angina, the younger brother, a sportsman, but a smoker, developed an antero-septal infarct at rest, which was complicated by complete persistent right bundle branch block. Ventriculography and coronary angiography were normal. Induced spasm tests were not performed. The elder brother presented an infero-apico-lateral infarct on effort, without any prodromal syndrome, which was complicated by apical akinesia. Ventriculography revealed mitral prolapse. Coronary angiography was normal and the methylergometrine test was negative. In relation to this example of familial infarction with normal coronary vessels, the authors review the features of this type of infarction reported in the literature which predominantly occurs in young people. They discuss the principal points of interest, including the incidence, the criteria of definition based on the coronary angiography, the elements of the prognosis, the pathophysiological mechanisms and the possibility of a genetic predisposition.

Adult↗