Experimental validation of methods for the measurement of coronary sinus blood flow in man

Abstract

The measurement accuracy of clinically applicable methods for blood flow measurement in coronary sinus -- continuous local thermodilution (LTD), differential pressure (DP), ultrasonic Doppler (US) and the electromagnetic flow measurement method (EMF) -- was examined in 15 anaesthetized closed chest dogs with left ventricle weights between 150 and 200 g. The LTD, DP, US and the EMF were examined in each experiment in the two following arrangements. 1. In coronary sinus -- left jugular vein by-pass: This arrangement allowed four reference methods for measurement of coronary sinus blood flow (CBF). 2. In "clinical" position, without by-pass, which allowed two reference methods for CBF measurements. The results on the measurement accuracy of the LTD, DP and US are, depending on the measurement arrangement, contradictory. In the by-pass arrangement 1 there was observed a good agreement of the LTD, DP and US CBF values with the reference values. In the "clinical" position, without by-pass 2 the measurement accuracy of LTD was not sufficient for exact measurement of CBF and derived parameters. The examined velocity tip flow probes (US, DP) gave no correlation with the reference methods. US and DP are even for semiquantitative estimation of CBF unsuitable. The EMF tip flow probe was for the CBF measurement unsuitable, because of disturbance by the electrical activity of myocardium.

A critical look at currently used indirect indices of myocardial oxygen consumption

“…Steady state conditions were determined by stability of ventricular and aortic pressure, dP/dtmax, myocardial blood flow and electrocardiogram over 3-5 minutes. 10. maximal rate of left ventricular pressure rise (dP/dtma x = 300-13,500 mm Hg/sec) 11. area beneath the total systolic ventricular pressure curve 12. myocardial blood flow (MBF = 30-650 ml/min 9 100 g) 13. myocardial oxygen consumption (MVO 2 = 3-36 ml/min 9 100 g).…”

“…myocardial blood flow x arterio-coronary-venous oxygen content difference) was calculated from these primary data. Details of the experimental procedure and the measurement accuracy of the differential pressure catheter, the pressure recording systems, and the oxygen saturation and content determinations have been described previously (8,9,10,11). All calculated indirect indices were compared with directly measured oxygen consumption by use of a Calculator (9820A) and a Plotter (9862A, Hewlett Packard, Colorado, USA).…”

A new model for testing therapeutic interventions during myocardial ischemia

“…Global mechanical performance was determined by measuring left ventricular systolic pressure and its first derivative by a tip manometer and the cardiac output by the right heart thermodilution method. As metabolic indicators of myocardial cell injury releases of potassium, phosphate, and lactate were calculated by arterio-coronary venous differences and coronary flow measured by a coronary sinus central venous bypass system including an electromagnetic flowmeter [5].…”

Changes in myocardial substrate and energy metabolism by S-(4)-hydroxyphenylglycine and an N-(6)-derivative of adenosine

“…The following parameters were recorded continuously: ECG extremity lead II, aortic pressure, left ventricular pressure (cathetertip pressure transducer), first derivative of left ventricular pressure and expiratory CO2-contcnt. Myocardial blood flow was measured by a coronary sinus central venous bypass system including an electromagnetic flow meter (22). Hemodynamics were varied over a wide range by application of atropine (0.5 mg) and infusion of dopamine (0.2-1.5 mg/min) and norepinephrine (0.04-0.30 mg/min) to achieve steady states of at least five minutes followed by periods of 15 minutes without [~-stimulation.…”