http://repub.eur.nl/res/aut/6405/ List of Publications en http://repub.eur.nl/static-eur/img/logo.png http://repub.eur.nl http://repub.eur.nl/res/pub/10232/ 2003-10-01T00:00:00Z AIMS: The purpose of this study was to investigate the relation between acute coronary flow reduction and arterial wall temperature. METHODS AND RESULTS: Five pigs with normal coronary arteries were catheterized. Arterial wall temperature was studied with a thermographic system that uses a 4-thermistor sensor tip. Flow velocity was studied at the same time and place with the temperature measurements, using a Doppler wire. In order to modify the coronary flow, a balloon was gradually inflated proximally to the thermographic sensors. Temperature differences and flow velocities were simultaneously recorded.Flow velocities above an average peak velocity (APV) of 9 cm/s were associated with unaffected temperature measurements. At flow velocities around 4 cm/s, the wall temperature was increased (deltaT=0.015+/-0.005 degrees C, P approximately 0.05), following the heart-rate. When flow velocity dropped further below this value, the local wall temperature was logarithmically increased to a maximum value observed at total vessel occlusion (deltaT=0.188+/-0.023 degrees C, P<0.001). CONCLUSION: The reduction of coronary flow has an effect on the arterial wall temperature. This effect however, appears only below a critical threshold of APV and in a logarithmic fashion. Above this threshold, temperature measurements should be unaffected from flow reductions and related to the regional temperature heterogeneity. http://repub.eur.nl/res/pub/4850/ 2001-01-30T00:00:00Z Background: Nonfluoroscopic electromechanical mapping (NEM) has been proposed as a new technique for the evaluation of electrical and mechanical functioning of the myocardium. In this system, linear local shortening (LLS) is the parameter used for assessment of local mechanical properties. To validate this parameter, we compared LLS with regional wall motion (RWM) data derived from contrast left ventriculograms acquired in the same patients. Methods and results: Angiographic left ventricular RWM was analyzed using the area–length method. The right anterior oblique view was divided in five segments, the left anterior oblique view in two. Through a comparison of enddiastolic and endsystolic areas drawn from a computer-defined central point to the respective wall delineation, RWM was calculated as change in area. In the first approach, we compared area changes to comparable NEM segments. In the second part of the study, LLS values for normokinetic, hypokinetic, akinetic and dyskinetic segments were correlated to the change in angiographic RWM. In the first approach, the overall comparison of segments yielded a correlation coefficient of 0.67 (P<0.0005). In the second part of the study, differences in LLS values between dyskinetic (LLS=−3.68±8.86%), akinetic (2.84±3.96%), hypokinetic (9.35±4.27%) and normokinetic (13.66±7.98%) segments were highly significant (overall ANOVA: P<0.0005). Conclusion: NEM is a powerful tool for invasive electromechanical assessment of myocardial function. http://repub.eur.nl/res/pub/4866/ 2000-01-01T00:00:00Z A67-year-old man with a history of hypertension and hypercholesterolemia was scheduled for elective direct stent implantation for a severe proximal left descending artery stenosis. Using the femoral approach, a 7-French Judkins left guiding catheter was placed in the left coronary ostium. To keep the activated clotting time >300 s, 10 000 IU of heparin and 250 mg of aspirin were given intravenously. After introducing an intermediate guide wire (Guidant Inc), we placed an AngioguardTM (Angioguard Inc) distal to the target lesion. This guidewire-based, filter-type device captures embolic debris while maintaining distal perfusion by means of an expandable umbrella. Successful direct stenting was performed with an Tristar 3.5/18-mm premounted stent (Guidant Inc) at an inflation pressure of 18 atm.