Intracoronary Blood Flow Velocity and Transstenotic Pressure Drop in an Awake Human Being During Coronary Vasodilation

The pressure drop over a coronary stenosis and the intracoronary Doppler blood flow velocity were measured at rest and during coronary vasodilation. We report the first observation that confirms the validity of fluid dynamic equations to describe the hemodynamics of a coronary stenosis based on quantitative arteriography in a human being. (J Interven Cardiol 1988:1:1) Copyrigh

Coronary flow reserve : a functional measure of stenosis severity

In 1959 Sones developed selective coronary cineangiography. To date, this technique has remained the only means available for the visualization of the coronary arterial system with such image contrast and resolution, that the presence and severity of coronary stenosis can be determined with sufficient accuracy. Consequently, coronary cineangiography has become the most important tool for clinical decision making, used by the physician caring for patients with coronary artery disease. However, of prime concern has been the relationship between the angiographic severity of the stenosis and the resulting reduction or limitation in coronary blood flow. The concept of coronary flow reserve has been developed as a means to describe the functional capacity of a coronary artery. Several techniques are currently under development to make the assessment of coronary flow reserve possible in awake humans. This thesis describes a radiographic technique to measure coronary flow reserve, that can be applied during routine diagnostic or interventional cardiac catheterization. Several methodological aspects on which no previous data existed, such as the role of pharmacological coronary vasodilation, radiographic data acquisition and digital data processing as well as application of this technique in several clinical conditions have been studied

Normalization of coronary flow reserve by percutaneous transluminal coronary angioplasty

Fifteen patients undergoing routine follow-up angiography 5 months after successful percutaneous transluminal coronary angioplasty (PTCA) without angina and with normal exercise thallium scintigraphy were selected for analysis. The coronary flow reserves of these patients were compared with those of 24 patients with angiographically normal coronary arteries to establish whether PTCA can restore to normal the coronary flow reserve of patients with chronic coronary artery disease. The quantitative cineangiographic changes and the concomitant alterations in coronary flow reserve as an immediate result of the PTCA and the subsequent changes 5 months later are described. Coronary flow reserve was measured with digital subtraction cineangiography. PTCA resulted in an increase in minimal obstruction area (mean +/- standard deviation) from 0.8 +/- 0.3 to 3.4 +/- 0.7 mm2 and in coronary flow reserve from 1.0 +/- 0.3 to 2.5 +/- 0.6. Five months later a further substantial and significant (p less than 0.05) late increase in obstruction area (3.8 +/- 0.9 mm2) and flow reserve (3.6 +/- 0.5) had occurred. In 11 of 15 patients coronary flow reserve was restored to normal. Changes in stenosis geometry are likely to be 1 of the major determinants of this late normalization of coronary flow reserve

Persistent hyperglycemia is an independent predictor of outcome in acute myocardial infarction

BACKGROUND: Elevated blood glucose values are a prognostic factor in myocardial infarction (MI) patients. The unfavourable relation between hyperglycemia and outcome is known for admission glucose and fasting glucose after admission. These predictors are single measurements and thus not indicative of overall hyperglycemia. Increased persistent hyperglycemia may better predict adverse events in MI patients. METHODS: In a prospective study of MI patients treated with primary percutaneous coronary intervention (PCI) frequent blood glucose measurements were obtained to investigate the relation between glucose and the occurrence of major adverse cardiac events (MACE) at 30 days follow-up. MACE was defined as death, recurrent infarction, repeat primary coronary intervention, and left ventricular ejection fraction equal to or smaller than 30%. RESULTS: MACE occurred in 89 (21.3%) out 417 patients. In 17 patients (4.1%) it was a fatal event. A mean of 7.4 glucose determinations were available per patient. Mean +/- SD admission glucose was 10.1 +/- 3.7 mmol/L in patients with a MACE versus 9.1 +/- 2.7 mmol/L in event-free patients (P = 0.0024). Mean glucose during the first two days after admission was 9.0 +/- 2.8 mmol/L in patients with MACE compared to 8.1 +/- 2.0 mmol/L in event free patients (P < 0.0001). The area under the receiver operator characteristic curve was 0.64 for persistent hyperglycemia and 0.59 for admission glucose. Persistent hyperglycemia emerged as a significant independent predictor (P < 0.001). CONCLUSION: Persistent hyperglycemia in MI has a stronger relation with 30-day MACE than elevated glucose at admission

Hyperglycaemia in critically ill patients: marker or mediator of mortality?

Acute hyperglycaemia has been associated with complications, prolonged intensive care unit and hospital stay, and increased mortality. We made an inventory of the prevalence and prognostic value of hyperglycaemia, and of the effects of glucose control in different groups of critically ill patients. The prevalence of hyperglycaemia in critically ill patients, using stringent criteria, approaches 100%. An unambiguous negative correlation between hyperglycaemia and mortality has been described in various groups of critically ill patients. Although the available evidence remains inconsistent, there appears to be a favourable effect of glucose regulation. This effect on morbidity and mortality depends on patient characteristics. To be able to compare results of future studies involving glucose regulation, better definitions of hyperglycaemia (and consequently of normoglycaemia) and patient populations are needed

Assessment of Coronary Flow Reserve During Angioplasty Using A Doppler Tip Balloon Catheter. Comparison With Digital Subtraction Cineangiography

Intracoronary blood flow velocity measurements with a Doppler probe and the radiographic assessment of myocardial perfusion with contrast media previously have been used to investigate regional coronary flow reserve. In the present study we applied both techniques in the same patients to measure the immediate improvement in coronary flow reserve as a result of angioplasty. In addition we compared papaverine induced hyperemia with reactive hyperemia following transient transluminal occlusion of a major coronary artery. In 13 consecutive patients with a single proximal stenosis, coronary flow reserve was measured pre‐ and postangioplasty by digital subtraction cineangiography, while pre‐ and postangioplasty Doppler measurements before and after papaverine were obtained in the proximal part of the stenotic vessel. After the last transluminal occlusion, reactive hyperemia recorded with the Doppler probe was also compared to the coronary flow reserve measurement obtained during papaverine induced hyperemia. As a result of the angioplasty, coronary flow reserve measured with the radiographic technique (mean ± SD) increased from 1.1 ± 0.4 to 2.2 ± 0.4 (P < 0.001), while coronary flow reserve measured with the Doppler probe (mean ± SD) increased from 1.2 ± 0.3 to 2.4 ± 0.4 (P < 0.001). Pharmacologically induced hyperemia measured with the radiographic technique and the Doppler probe were linearly related (r = 0.91 with a SEE 0.3) and confirmed the reliability of the intracoronary measurements. Using these two independent techniques, coronary flow reserve immediately after angioplasty was found to be substantially improved but still abnormal. In addition, the magnitude of hyperemia induced by papaverine was comparable to the reactive hyperemia following transluminal occlusion, although the latter measurement was recorded with the angioplasty catheter still across the dilated lesion. (J Interven Cardiol, 1988:1:1) Copyrigh

Quantitative image analysis for the detection of motion artefacts in coronary artery computed tomography

Multi detector-row CT (MDCT), the current preferred method for coronary artery disease assessment, is still affected by motion artefacts. To rule out motion artefacts, qualitative image analysis is usually performed. Our study aimed to develop a quantitative image analysis for motion artefacts detection as an added value to the qualitative analysis. An anthropomorphic moving heart phantom with adjustable heart-rate was scanned on 64-MDCT and dual-source-CT. A new software technique was developed which detected motion artefacts in the coronaries and also in the myocardium, where motion artefacts are more apparent; with direct association to the qualitative analysis. The new quantitative analysis managed to detect motion artefacts in phantom scans and relate them to artefact-induced vessel stenoses. Quantifying these artefacts at corresponding locations in the myocardium, artefact-induced vessel stenosis findings could be avoided. In conclusion, the quantitative analysis together with the qualitative analysis rules out artefact-induced stenosis