This study was performed because of observed differences between dye dilution cardiac output and the Fick cardiac output, calculated from estimated oxygen consumption according to LaFarge and Miettinen, and to find a better formula for assumed oxygen consumption. In 250 patients who underwent left and right heart catheterization, the oxygen consumption VO2 (ml.min-1) was calculated using Fick's principle. Either pulmonary or systemic flow, as measured by dye dilution, was used in combination with the concordant arteriovenous oxygen concentration difference. In 130 patients, who matched the age of the LaFarge and Miettinen population, the obtained values of oxygen consumption VO2(dd) were compared with the estimated oxygen consumption values VO2(lfm), found using the LaFarge and Miettinen formulae. The VO2(lfm) was significantly lower than VO2(dd); -21.8 +/- 29.3 ml.min-1 (mean +/- SD), P < 0.001, 95% confidence interval (95% CI) -26.9 to -16.7, limits of agreement (LA) -80.4 to 36.9. A new regression formula for the assumed oxygen consumption VO2(ass) was derived in 250 patients by stepwise multiple regression analysis. The VO2(dd) was used as a dependent variable, and body surface area BSA (m2). Sex (0 for female, 1 for male), Age (years), Heart rate (min-1) and the presence of a left to right shunt as independent variables. The best fitting formula is expressed as: VO2(ass) = (157.3 x BSA + 10.0 x Sex - 10.5 x In Age + 4.8) ml.min-1, where ln Age = the natural logarithm of the age. This formula was validated prospectively in 60 patients. A non-significant difference between VO2(ass) and VO2(dd) was found; mean 2.0 +/- 23.4 ml.min-1, P = 0.771, 95% Cl = -4.0 to +8.0, LA -44.7 to +48.7. In conclusion, assumed oxygen consumption values, using our new formula, are in better agreement with the actual values than those found according to LaFarge and Miettinen's formulae.

SUMMARY Percutaneous transluminal balloon angioplasty was performed in five children with coarctation restenosis. After angioplasty the pressure gradient had decreased considerably in four patients. In all patients aortography showed an increase in the diameter of the lumen at the site of the restenosis. All patients were normotensive the day after angioplasty. There were no complications during or after the procedure. one by a subclavian artery flap procedure, and one by end to side anastomosis of the left subclavian artery on the descending aorta because of the local anatomical situation. The ages at primary repair ranged from 3 days to 6-2 years (mean 1-7 years). In four children angioplasty was performed under general anaesthesia.The pressure gradients across the restenosis were measured and the cardiac indices were calculated from dye dilution curves before and 20 minutes after angioplasty. Percutaneous transluminal angioplasty was performed with Meditech balloon dilatation catheters. The diameters of the balloons that were used ranged from 8 mm to 18 mm and the size was selected according to the coarctation diameter (measured at aortography) multiplied by 2-5. The balloon diameter never exceeded 1 2 x the diameter of the descending aorta. The dilatation catheter was positioned at the site of the restenosis over a guide wire the tip of which was advanced into the ascending aorta. Under continuous fluoroscopy the balloon was inflated to pressures of 4 atm with a 3:1 dilution of contrast medium.This procedure was carried out three times. Each inflation lasted for about 10 seconds. After angioplasty the balloon catheter was withdrawn, and the tip of the guide wire was kept in the ascending aorta. A multipurpose catheter was then carefully introduced over the guide wire to the ascending aorta. This catheter was used for repeated aortography, pressure measurements, and dye sampling for calculation of the cardiac indices.

A crossover study was performed to compare the hemodynamic effects of the iso-osmolar contrast agent iodixanol (Visipaque) 320 mg I/ml to those of the low-osmolar iohexol (Omnipaque) 350 mg I/ml. The main hypothesis was that iodixanol and iohexol would affect left ventricular end-diastolic pressure (LVEDP) to different degrees. In 48 patients with reduced cardiac function (mean ejection fraction 33. 4%), one ventricular injection was performed with each contrast medium. Ventricular, aortic and right atrial pressures and heart rate were measured continuously. Cardiac output (using Fick's principle) and systemic vascular resistance were calculated. LVEDP increased with both agents, but significantly less after iodixanol than after iohexol (P < 0.01), also in subgroups of patients in whom baseline LVEDP was severely increased and in whom 3-vessel disease was present. Immediate changes in variables reflecting vasodilatation were similar with both agents. In conclusion, both contrast agents influenced hemodynamics during ventriculography, but iodixanol had significantly less influence on LVEDP than did iohexol.

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OBJECTIVES.: We sought to study the incidence and clinical correlates of elevated filling pressures in ST-elevation myocardial infarction (STEMI) patients, without physical signs of heart failure and treated with primary coronary angioplasty. BACKGROUND.: Haemodynamic data, as measured with a Swan-Ganz catheter, are not routinely obtained in STEMI patients. At admission, low blood pressure, increased heart rate, sweating, increased respiration rate, rales, oedema, and a third heart sound are indicative of heart failure. METHODS.: All consecutive STEMI patients were monitored by a Swan-Ganz catheter and central venous pressure (CVP), pulmonary capillary wedge pressure (PCWP), pulmonary artery pressure (PAS) and cardiac index (CI) were measured. To investigate the clinical correlates of the haemodynamic status patients were classified according to previously defined haemodynamic criteria. RESULTS.: We studied 90 patients, aged 60.5+/-13.1 year, 76% were male. Mortality at 30 days was 2/90 (2.2%). Patients with impaired haemodynamics presented later and had larger myocardial infarct sizes. CVP, PCWP and PAS were above normal in 36 (40%) patients. CONCLUSION.: A large proportion of STEMI patients without physical signs of heart failure have elevation of right- as well as left-sided cardiac filling pressures. (Neth Heart J 2007;15:95-9.).