Left ventricular performance is closely related to the physical properties of the arterial system: Landmark clinical investigations in the 1970s and 1980s.

Left ejection fraction (LVEF)--resulting from the difference between end-diastolic volume (EDV) and end-systolic volume (ESV), divided by EDV--is a poor index of left ventricular (LV) systolic performance due to its dependency on load conditions, inotropic state and LV remodelling. The characteristic impedance of the ascending aorta (Zc) integrates factors opposing LV ejection during the early ejection period when arterial wave reflection can be neglected. Zc is related to the pressure wave velocity (C) and the cross-sectional area of the aorta.

[Brain natriuretic peptide (BNP) in coronary insufficiency: relationship with left ventricular filling and exercise tolerance].

Brain natriuretic peptide (BNP) is a recently discovered peptide, secreted by the atria and ventricles in response to parietal distension. It was recently proposed as a screening test for left ventricular failure. The authors assayed this peptide at rest in 37 patients with chronic heart failure due to left ventricular systolic dysfunction and another 20 patients with various diseases (respiratory failure, cirrhosis, heart transplantation, "diastolic" heart failure) but normal left ventricular systolic function.

Combined dipyridamole-exercise stress echocardiography for detection of myocardial ischemia in hemodialysis patients: an alternative to stress nuclear imaging.

Background: Stress nuclear imaging is the noninvasive technique currently used to detect coronary artery disease (CAD) in dialysis patients. Stress echocardiography is recognized as an alternative to stress nuclear imaging for the general population. The aim of this study is to assess the diagnostic accuracy of stress echocardiography for detecting myocardial ischemia in hemodialysis patients.

Cardiac metaiodobenzylguanidine uptake in patients with moderate chronic heart failure: relationship with peak oxygen uptake and prognosis.

Objectives: This prospective study was undertaken to correlate early and late metaiodobenzylguanidine (MIBG) cardiac uptake with cardiac hemodynamics and exercise capacity in patients with heart failure and to compare their prognostic values with that of peak oxygen uptake (VO2).

Background: The cardiac fixation of MIBG reflects presynaptic uptake and is reduced in heart failure. Whether it is related to exercise capacity and has better prognostic value than peak VO2 is unknown.

[Acute myocardial infarction. Experiences of the referral network of the Beaujon and Bichat hospitals (with the collaboration of the Emergency Medical and Resuscitation Service of Beaujon)].

Objectives: Hospital management of acute myocardial infarction raises many problems in terms of medical care and organization, especially concerning the use or not of emergency corongraphy and angiography. We assessed the pertinence and consequences of a referral network operating between two cardiology units at the Beaujon and Bichat hospitals in Paris. All interventional procedures were performed at the Bichat unit.

Diagnostic accuracy and prognostic value of combined dipyridamole-exercise thallium imaging in hemodialysis patients.

Background: Non-invasive detection of coronary artery disease in dialysis patients, a major cause of mortality, often remains difficult. The aim of the study was to test the diagnostic and prognostic accuracies of combined dipyridamole-exercise thallium imaging in dialysis patients.

Methods: Dipyridamole-exercise thallium imaging and coronary angiography were both performed prospectively in 60 asymptomatic hemodialysis patients who were followed up, long term, by recording any major coronary event.

Left ventricular-arterial system coupling at peak exercise in dilated nonischemic cardiomyopathy.

We assessed the ventricular-arterial coupling at peak exercise in 20 patients with dilated cardiomyopathy (ejection fraction, 27+/-12%) and 7 normal subjects by radionuclide ventriculography during exercise, coupled with respiratory gas analysis. The end-systolic pressure-volume ratio, taken as an index of contractility, and the effective arterial elastance were calculated at rest and at peak exercise. The end-systolic pressure/volume ratio increased from 3.

[Evaluation of the cost of a systematic early reperfusion of the infarction artery by primary or salvage angioplasty].

In order to evaluate the cost of a strategy designed to ensure a maximal early patency rate of the coronary artery responsible for acute myocardial infarction, we retrospectively studied 112 unselected, consecutive patients, treated during the 6 hours following onset of symptoms, either by intravenous thrombolysis (group 1, n = 57) followed by coronary angiography at the 90 th minute, and if necessary rescue angioplasty, or by primary angioplasty (group 2, n = 49), or finally by simple conventional medical treatment (group 3, contraindications to thrombolysis and catheterization, n = 6). The costs of medical treatment were expressed as standard mean costs, and were compared with total hospital expenditure. The overall hospital mortality was 8.

Comparison of the long-term prognostic value of peak exercise oxygen pulse and peak oxygen uptake in patients with chronic heart failure.

Objective: To evaluate the ratio of peak oxygen consumption to peak heart rate (peak oxygen pulse) as a predictor of long term prognosis in chronic heart failure.

Patients And Setting: 178 consecutive heart failure patients recruited to the cardiology department of a tertiary referral centre between 1986 and 1993.

Design: Bicycle ergometry with measurement of respiratory exchange.

Relationship between left ventricular hypertrophy, myocardial contractility, and load conditions in hemodialysis patients: an echocardiographic study.

Left ventricular hypertrophy (LVH) is common and is an independent cardiac risk factor in dialysis patients. The aim of this study was to assess hemodynamic determinants of LVH and, more particularly, the relationship between left ventricular mass, myocardial contractility, and load conditions. Eighty dialysis patients aged 51 +/- 15 years were prospectively studied by echocardiography.

Comparison of left ventricular responses to the six-minute walk test, stair climbing, and maximal upright bicycle exercise in patients with congestive heart failure due to idiopathic dilated cardiomyopathy.

Submaximal exercise tests have been advocated to assess exercise capacity in chronic heart failure, but hemodynamic responses have not been characterized. To determine left ventricular (LV) responses during submaximal exercise, the LV ejection fraction (EF) and volumes were evaluated by using an ambulatory radionuclide detector in 13 patients with idiopathic dilated cardiomyopathy during upright maximal graded bicycle exercise, stair climbing and a 6-minute walk test. The 3 tests elicited different responses in volumes and, to a lesser degree, in LVEF.

Delayed attainment of peak oxygen consumption after the end of exercise in patients with chronic heart failure.

Peak oxygen uptake (VO2) is attained at peak exercise in normal subjects. Recently, it was shown that the kinetics of the VO2 increase during exercise is slowed in chronic heart failure (CHF). We hypothesized that this may delay maximal VO2 after the end of exercise.

Determination of left ventricular cardiac volume by simultaneous radionuclide angiography and measurement of oxygen consumption at rest and during maximal exercise: a comparison of two non-invasive isotopic procedures.

The investigation of left ventricular contractile reserve usually requires the determination of left ventricular volume, but its measurement with radionuclide angiography is difficult. The aim of this study was to determine left ventricular volume directly during exercise by the simultaneous measurement of peak exercise left ventricular ejection fraction (LVEF) and oxygen consumption (VO2max) and to compare the results with another geometric method. In the absence of lung disease, the systemic arteriovenous oxygen difference (DAVmax) during maximal exercise converges to 0.

Transient fall in oxygen intake during exercise in congestive heart failure.

We report four cases in which oxygen intake abruptly decreased during a graded exercise test. In all these cases, there was an acute event (arrhythmia, mitral regurgitation) that had very likely resulted in a decrease in cardiac output. These studies provide new evidence of oxygen intake dependence on oxygen transport, even in nonsteady-state situations.

Serial assessment of cardiopulmonary exercise capacity after cardiomyoplasty for either ischemic or idiopathic dilated cardiomyopathy.

Cardiomyoplasty is a surgical procedure aimed at assisting the left ventricle during ejection. We describe the long-term effects of cardiomyoplasty on peak exercise capacity, with serial assessments for up to 3 years after operation. Sixteen patients (12 in New York Heart Association class III and 4 in class IV) were enrolled.

Effects of aging on left ventricular-arterial coupling in man: assessment by means of arterial effective and left ventricular elastances.

The ejection fraction (EF) is a load-dependent index of the systolic function of the left ventricle (LV), which depends on the 'functional' coupling of the LV with the arterial system, evaluated by the ratio between arterial effective elastance (Ea) to end-systolic left ventricular elastance. The spectrum of changes in LV and the arterial system during aging has not been studied by means of coupled analysis of elastances. Twenty-five normotensive healthy subjects aged from 22 to 68 years underwent hemodynamic and angiographic studies.

[Exercise capacity after heart transplantation].

Independently of phenomena related to rejection, atherosclerosis of the grafted heart or high blood pressure, there exists a qualitative and quantitative degradation of response to exercise in heart transplant recipients. Maximal oxygen consumption is generally reduced to 40 to 60% of normal levels. There are several interactive mechanisms.

[Diagnostic value of myocardial thallium stress scintigraphy in the detection of coronary artery disease in patients undergoing chronic hemodialysis].

Atherosclerotic heart disease is the leading cause of death in patients with end stage renal disease, but its non invasive detection remains difficult because of a low efficacy of exercise testing. The aim of the study was to evaluate diagnostic accuracy of thallium myocardial imaging after dipyridamole combined with exercise. Forty two chronic dialysis patients (34 men, 8 women) aged 55 +/- 11 years (range: 36 to 75) without symptom of angina nor myocardial infarction were studied.

Prolonged kinetics of recovery of oxygen consumption after maximal graded exercise in patients with chronic heart failure. Analysis with gas exchange measurements and NMR spectroscopy.

Background: Patients with chronic heart failure (CHF) often complain of prolonged dyspnea after exercise. The determinants of oxygen consumption after exercise in these patients are unknown. We hypothesized that the kinetics of oxygen consumption recovery after graded exercise was prolonged in parallel with the recovery of muscle energy stores, was not affected by the exercise level, and could be used to assess the circulatory response to exercise.

Detection of coronary artery disease in diabetic patients.

Coronary artery disease may be difficult to detect in diabetic patients. This study was designed to determine the specificity and sensitivity of three noninvasive tests. Accordingly, the results of 48-h ambulatory electrocardiogram (ECG) monitoring, maximal ECG exercise test, and intravenous dipyridamole myocardial thallium scintigraphy were compared in 59 middle-aged diabetic patients who were consecutively selected for suspected coronary artery disease.

Comparison using dynamic vectorcardiography and MIBI SPECT of ST-segment changes and myocardial MIBI uptake during percutaneous transluminal coronary angioplasty of the left anterior descending coronary artery.

The quantitative relation between ST-segment changes and the severity and extent of myocardial ischemia during coronary occlusion remains unclear. This study assesses whether ST-segment changes during percutaneous transluminal coronary angioplasty (PTCA) correlate with the amount of myocardium at risk, measured with technetium-99m hexakis 2-methoxyisobutyl isonitrile (MIBI; also called sestamibi) single-photon emission computed tomography (SPECT). Quantitative continuous dynamic vectorcardiography was performed during PTCA of the left anterior descending coronary artery in 11 patients (mean age 64.

Influence of preload reserve on stroke volume response to exercise in patients with left ventricular systolic dysfunction: a Doppler echocardiographic study.

Objectives: This study evaluated the role of preload reserve in the stroke volume response to exercise in patients with left ventricular systolic dysfunction by assessing the relation between stroke volume and late left ventricular diastolic filling during exercise.

Background: In patients with left ventricular diastolic dysfunction, the absence of left ventricular distension is the fundamental mechanism explaining the nonaugmentation of stroke volume during exercise.

Methods: In 32 patients with left ventricular systolic dysfunction and 16 healthy control subjects, mitral and aortic velocities were recorded by Doppler echocardiography at rest and during submaximal supine bicycle exercise.

[Critical analysis of scales of quality of life in cardiology; applications to cardiac insufficiency].

Scales of quality of life have only recently been imposed in cardiology. Essentially an Anglosaxon invention, they have been used for evaluating most treatment of cardiac failure. The main qualities of a good quality of life questionnaire are its sensitivity, its reproducibility and its validity.