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At least 343 records · Page 19Linked to original sources

How well does radionuclide dipyridamole stress testing detect three-vessel coronary artery disease and ischemia in the region supplied by the most stenotic vessel?

PURPOSE: This study was done to evaluate the accuracy of radionuclide dipyridamole stress imaging to detect multivessel disease and ischemia in segments of myocardium supplied by the most stenotic vessel. METHODS: A retrospective analysis of consecutive patients with known triple-vessel disease of at least 50% stenosis in each of the three major epicardial coronary arteries who had exercise (n=44) or dipyridamole (n=86) stress testing, or both, within 6 months of coronary angiography. RESULTS: The accuracy of dipyridamole stress testing to detect three-vessel disease was 52% and ischemia was detected in the region supplied by the most stenotic vessel in 67% of patients. The sensitivity and specificity rates of radionuclide imaging to detect ischemia in the region supplied by the vessel of tightest stenosis were 69% and 74% for the left anterior descending coronary artery (LAD), 61% and 78% for the right coronary artery (RCA), and 61% and 57% for the left circumflex coronary artery (LCX). Based on these values, in 39% of patients in whom the RCA or LCX was the most stenotic vessel and in 31% of patients in whom the LAD was the most stenotic vessel, perfusion defects were not present on their nuclear scans. CONCLUSIONS: These results have important implications for interventional cardiologists who perform angioplasty on the most stenotic vessel, because the regions supplied by these vessels may not be the most ischemic. Furthermore, dipyridamole stress imaging may significantly underestimate the number of patients with substantial three-vessel coronary artery disease when qualitative imaging is done.

Aged↗

Alterations in left ventricular shape in patients with angina and single-vessel coronary disease.

BACKGROUND: Left ventricular shape alterations, apparently independent of acute ischaemia or previous myocardial infarction, have been described in patients with stable angina. Our previous observations had been made in a group of patients with multivessel coronary disease; it was therefore not possible to establish a clear-cut anatomical relationship between the location of ischaemia and the changes in left ventricular contour. The aim of this work was to extend the previous observations by analysing left ventricular shape in patients with angina and single-vessel coronary disease, in whom the potentially ischaemic region can be easily localized. METHODS: Fifty-eight patients with stable or unstable angina were retrospectively selected if they had single-vessel disease, normal regional and global function and no previous myocardial infarction: 37 had a critical stenosis (more than 75% diameter reduction) of the left anterior descending artery and 21 had a critical stenosis of the right coronary artery. Patients with left ventricular hypertrophy or any other obvious cause of myocardial dysfunction were excluded. All patients underwent haemodynamic study. Left ventricular global shape was evaluated by calculating eccentricity and circular indices; regional curvature was measured at 90 points along the angiographic contours (right anterior oblique projection) by applying a windowed Fourier analysis. Results were compared with those obtained in 16 normal subjects. RESULTS: Patients had significant diastolic alterations in left ventricular shape, which assumed a more rounded aspect than normal. Regional curvature was significantly altered at several points pertaining to the anterior, apical and inferior segments. The pattern of changes in regional curvature was about the same in the left anterior descending and right coronary artery groups, with the involvement of regions supplied by angiographically normal arteries, although the extent of alteration was greater in patients with stable, chronic angina (more than 6 months) and in patients with stenosis of the left anterior descending artery. CONCLUSIONS: Patients with angina, no previous myocardial infarction and normal systolic function had left ventricular shape abnormalities either in the potentially ischaemic or in the remote zones. The mechanism leading to these changes is still speculative.

Adult↗

Pharmacological evaluation of new calcium antagonists: 2-substituted 3-dimethylamino-5,6-methylenedioxyindenes. Effects on isolated hearts and coronary vessels.

The 2-n-propyl and 2-n-butyl aminoindene hydrochlorides were previously reported to interfere with excitation-contraction coupling in uterine and intestinal smooth muscle, and with stimulus-secretion coupling in the adrenal medulla, by interfering with the action of calcium at an intracellular site. The present investigation was designed to apply this knowledge to the potential coronary and cardiac effects of such a pharmacological action. The 2-n-propyl and 2-n-butyl aminoindenes (5 X 10(-6)-10(-4) M) produced a concentration-dependent relaxation of potassium-contracted strips of bovine extramural coronary vessels, which was reversible upon elevation of the calcium concentration in the medium. In the nonstimulated isolated perfused rabbit heart, the 2-n-propyl aminoindene (3 X 10(-5) M) and the 2-n-butyl aminoindene (3 X 10(-5) and 10(-4) M) increased coronary flow without affecting cardiac chronotropic activity. However, the 2-n-propyl aminoindene (3 X 10(-5) and 10(-4)M) and the 2-n-butyl aminoindene (10(-4) M) produced a negative inotropic action in this preparation. The combination of coronary dilation and decreased force of cardiac contraction may represent desirable properties for drugs useful in the treatment of ischemic heart disease.

Animals↗

[A successful case of hybrid therapy for the left main trunk and triple coronary vessel lesions with acute myocardial infarction and cardiogenic shock].

A 86-year-patient who had acute myocardial infarction and critical cardiogenic shock was diagnosed to have the left main trunk (LMT) and triple vessel disease. Emergent coronary artery bypass grafting to the left anterior descending artery was performed using saphenous vein graft without cardiopulmonary bypass through median sternotomy. On the 41st postoperative day, catheter intervention was performed to the remaining lesions by stenting of LMT and percutaneous transluminal coronary angioplasty to the right coronary artery lesions. Tl scintigraphy showed remarkable reduction of myocardial ischemia. Hybrid therapy is the effective new strategy for critical cases which cannot be successfully and securely treated by medical or surgical approach alone.

Aged↗

Segmental study of the terminal coronary vessels in coarctation of the aorta: a natural model for study of the effect of coronary hypertension on human coronary circulation.

An electron microscopic study of the coronary terminal circulation (starting with the small coronary arteries) was carried out on small pieces of myocardium operatively resected from the left ventricle on 11 patients with coarctation of the aorta. The patients were 4 to 20 years of age. Structural modifications were found in the small coronary arteries and arterioles. Two patterns of morphologic alterations were noted in these small resistance vessels. In the first pattern, seen in most of the children, the components of the arterial wall were still distinguishable, and well represented portions of smooth muscle layers were visualized together with muscle cells showing signs of degeneration and more or less widespread collagenous islets. The second pattern, seen in young adults, was characterized by a total collagenous transformation of the arterial wall. In contrast, the smaller microvessels (precapillary sphincter, metarterioles and capillaries) appeared free of pathologic change. It is postulated that the precapillary sphincters play a special protecting and regulating role in the coronary microcirculation in such cases with elevated coronary pressure. It is suggested that surgery should be performed at an early age to prevent further development of structural changes in the microvessels. The microcirculatory damage may contribute to the increased surgical mortality in patients with coarctation of the aorta operated on at a later age. These findings should trigger further research on the small coronary vessels in systemic hypertension.

Adult↗

Prevalence of left main coronary artery disease, of three- or four-vessel coronary artery disease, and of obstructive coronary artery disease in patients with and without peripheral arterial disease undergoing coronary angiography for suspected coronary artery disease.

Data from the present investigation showed that the prevalence of current cigarette smoking, current or ex-cigarette smoking, systemic hypertension, diabetes mellitus, and dyslipidemia was significantly higher in patients with peripheral arterial disease (PAD) than in patients without PAD. The present report also showed that compared with patients without PAD undergoing coronary angiography for suspected coronary artery disease (CAD), patients with PAD undergoing coronary angiography for suspected CAD had a higher prevalence of left main CAD (18% vs <1%), a higher prevalence of 3- or 4-vessel CAD (63% vs 11%), and a higher prevalence of obstructive CAD (98% vs 81%).

Adult↗

[The recanalization of the chronically occluded infarct vessel in single-vessel coronary disease. The reduction of cardiac events in long-term clinical follow-up].

OBJECTIVE: The prognostic significance of recanalisation of a chronically occluded infarct vessel in single-vessel coronary disease remains controversial, in contrast to early re-opening of the infarct vessel in the acute state of infarction. It was the purpose of this prospective study to discover whether successful recanalisation in the former influences the incidence of cardiac events (death, infarction, by-pass operation) and clinical symptoms in the long term. PATIENTS AND METHOD: Recanalisation procedures were successful in 58, unsuccessful in 41 of 99 patients (81 men, 18 women; mean age 55 [28-79] years) with anterior wall (n = 53) or posterior wall (n = 46) myocardial infarction (AMI and PMI, respectively). The two groups were similar with respect to age, sex, left-ventricular function, indication, exercise capacity and premedication. But the interval between infarction and recanalisation was shorter in the patients who had successful recanalisation (5.1 +/- 5.3 vs 7.8 +/- 7.6 months; P < 0.05). Mean follow-up period for all patients was 55.8 +/- 8.9 months after the recanalisation procedure. RESULTS: There were significantly fewer cardiac events after successful than failed recanalisation, both for the total group of patients (5% vs 23%; P < 0.01) and those with AMI (9 vs 36%; P = 0.012). In the patients with PMI there was only a trend in favour of those with successful recanalisation (0% vs 14%; P = 0.058). Symptomatic improvement was reported by 73% of patients after successful but only 40% after failed recanalisation (P < 0.01). CONCLUSION: The results provide pointers towards prognostic indications of recanalisation even after chronic occlusion of the infarct vessel. The procedure should therefore be attempted if the occlusion is morphologically suitable.

Angioplasty, Balloon, Coronary↗

A premenopausal woman presenting with acute myocardial infarction of three different coronary vessels within 1 year: role of lipoprotein(a).

A premenopausal female patient presented with acute myocardial infarction of 3 different coronary vessels at different times within 1 year. These events were caused not by restenotic lesions after balloon angioplasty but by new lesions, which were successfully treated by primary angioplasty. Although she had a history of hypertension, type IIB hyperlipidemia, and diabetes, they had been well-controlled on medication. An elevated serum lipoprotein(a) level may have played a role in this rapid angiographic progression.

Angioplasty, Balloon↗

Response of conductance and resistance coronary vessels to scalar concentrations of acetylcholine: assessment with quantitative angiography and intracoronary Doppler echography in 29 patients with coronary artery disease.

Abnormal vasoreactivity of the large conductance arteries has been observed in the presence of impaired endothelial function. More recently, experimental and clinical reports have shown that in early coronary atherosclerosis the impairment of the endothelium-mediated vasodilatation also involves the resistance arteries. The aim of this study is the correlation of endothelium-dependent vasodilatation of conductance and resistance vessels in coronary arteries without significant stenoses. In 29 patients (aged 57 +/- 9 years, 24 men and 5 women) undergoing coronary angioplasty, a Doppler guide wire and a perfusion catheter were introduced into the proximal segment of an artery with less than 30% diameter stenosis. Selective infusions of papaverine (bolus of 7 mg), acetylcholine (continuous infusion of 0.036, 0.36, and 3.6 micrograms/ml at a flow rate of 2 ml/min), and isosorbide dinitrate (bolus of 3 mg) were sequentially performed. Heart rate, aortic blood pressure, and blood flow velocity were continuously measured. Mean cross-sectional areas of a proximal and a distal arterial segment were measured in baseline conditions, at the end of each infusion of acetylcholine, and at the peak effect of isosorbide dinitrate with quantitative angiography (CAAS System; Pie Medical Data, Maastricht, The Netherlands). Coronary blood flow was calculated from the time-averaged flow velocity and the cross-sectional area at the site of the Doppler sample volume. Coronary flow resistance was calculated as mean aortic pressure divided by coronary flow. All of the concentrations of acetylcholine induced a significant vasoconstriction of the studied artery. At the maximal concentration of acetylcholine all but three patients (90%) showed a reduction of cross-sectional area (-24% +/- 20% and -22% +/- 20% for the proximal and distal segments, respectively, p < 0.00001). Flow velocity showed a significant increase only with the two highest concentrations of acetylcholine. The maximal concentration induced a 105% +/- 138% increase from the baseline flow velocity (p < 0.001). The coronary flow changes after acetylcholine showed a large interpatient variability, with a mean increase from baseline after the highest dose of +43% +/- 85% (range, -60% +/- 239%), with the presence of a flow reduction in 10 patients (35%). No clinical or angiographic variables showed a significant correlation with the cross-sectional area, flow velocity, and flow changes after infusion of acetylcholine.(ABSTRACT TRUNCATED AT 400 WORDS)

Acetylcholine↗

Comparison of exercise electrocardiography and quantitative thallium imaging for one-vessel coronary artery disease.

The relative value of exercise electrocardiography and computer analyzed thallium-201 imaging was compared in 124 patients with 1-vessel coronary artery disease (CAD). Of these, 78 had left anterior descending (LAD), 32 right and 14 left circumflex (LC) CAD. In patients with no previous myocardial infarction (MI), thallium imaging was more sensitive than the electrocardiogram (78% vs 64%, p less than 0.01), but in patients with previous MI, sensitivity was similar. Further, thallium imaging was more sensitive only in LAD and LC disease. Redistribution was compared with ST-segment depression as a marker of ischemia. Only in patients with prior MI (76% vs 44%, p less than 0.01) and only in LC and right CAD did redistribution occur more often than ST depression. Thallium imaging was more accurate in localizing stenoses than the electrocardiogram (p less than 0.001), but did not always correctly predict coronary anatomy. Septal thallium defects were associated with LAD disease in 84%, inferior defects with right CAD in 40% and posterolateral lesion defects with LC CAD in 22%. The results indicate the overall superiority of thallium imaging in 1-vessel CAD compared with exercise electrocardiography; however, there is a wide spectrum of extent and location of perfusion defects associated with each coronary artery. Thallium imaging complements coronary angiography by demonstrating the functional impact of CAD on myocardial perfusion.

Adult↗