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PubMed1994

Transesophageal echocardiographic assessment of left ventricular function during apnea testing for brain death.

The effects of apnea testing-induced respiratory acidosis on left ventricular function (LVF) are still controversial. The aim of the study was to assess LVF during apnea testing using transesophageal echocardiography (TEE). Twenty consecutive patients suspected of brain death, hemodynamically stable, and considered as potential organ donors were prospectively studied. A 20-min apnea test was performed after obtaining a PaCO2 > 35 mmHg and 20 min of FIO2 1 ventilation. LVF was assessed using TEE with a CFM 750 (Diasonic) connected to a 5 MHz probe. Heart rate (HR), mean arterial pressure (MAP), left ventricle end-diastolic and systolic area (LVEDA, LVESA), and LVF assessed by fractional area changes (FAC), systolic wall motion (SWM) scores, and blood gases were recorded at baseline, and after 5, 10, 15, and 20 min of apnea testing. In 19 patients, no spontaneous respiratory movement occurred during the standard 20-min period. In one patient (No. 15), the apnea test had to be stopped after 10 min because of hypoxia. HR, LVEDA, LVESA, and SWM were not significantly modified during the study. There was a progressive statistically significant decrease in MAP during apnea (from 77 +/- 10 to 63 +/- 11 mmHg), associated with a statistically significant increase in FAC at 20 min (from 48 +/- 13 to 56 +/- 8%). PaCO2 progressively rose (from 40 +/- 3 to 95 +/- 11 mmHg), associated with a decrease in pH (from 7.42 +/- 0.06 to 7.09 +/- 0.08). At the same time, PaO2 decreased slightly in all patients, but values remained well above hypoxic levels, except for one patient. Despite severe respiratory acidosis the increase in FAC suggests that apnea testing is well tolerated for brain death assessment.

Acidosis, Respiratory↗
PubMed2003

Influence of passive leg elevation on the right ventricular function in anaesthetized coronary patients.

INTRODUCTION: The aim of the present study was to evaluate the haemodynamic effects of passive leg elevation on the right ventricular function in two groups of patients, one with a normal right ventricular ejection fraction (RVEF) and one with a reduced RVEF. METHODS: Twenty coronary patients undergoing elective coronary artery bypass grafting surgery were studied by a RVEF pulmonary artery catheter. The haemodynamic data reported were collected before the induction of anaesthesia (time point 1), just before (time point 2) and 1 min (time point 3) after the legs were simultaneously raised at 60 degrees, and 1 min after the legs were lowered (time point 4). The patients were divided into two groups: group A, with preinduction RVEF > 45%; and group B, with preinduction RVEF < 40%. RESULTS: In group A (n = 10), at time point 3 compared with time point 2, the heart rate significantly decreased (from 75 +/- 10 to 66 +/- 7 beats/min). The right ventricular end diastolic volume index (from 105 +/- 17 to 133 +/- 29 ml/m2), the right ventricular end systolic volume index (from 61 +/- 13 to 77 +/- 24 ml/m2), the systolic systemic arterial/right ventricular pressure gradient (from 93 +/- 24 to 113 +/- 22 mmHg) and the diastolic systemic arterial/right ventricular pressure gradient (from 58 +/- 11 to 66 +/- 12 mmHg) significantly increased. Also in group A, the cardiac index did not significantly increase (from 3.28 +/- 0.6 to 3.62 +/- 0.6 l/min/m2), the RVEF was unchanged, and the right ventricular end diastolic volume/pressure ratio (RVED V/P) did not significantly decrease (from 48 +/- 26 to 37 +/- 13 ml/mmHg). In group B (n = 6) at the same time, the heart rate (from 72 +/- 15 to 66 +/- 12 beats/min), the right ventricular end diastolic volume index (from 171 +/- 50 to 142 +/- 32 ml/m2) and the RVED V/P (from 71 +/- 24 to 39 +/- 7 ml/mmHg) significantly decreased. The cardiac index and the diastolic systemic arterial/right ventricular pressure gradient were unchanged in group B, while the RVEF and the systolic systemic arterial/right ventricular pressure gradient did not significantly increase, and the right ventricular end-systolic volume index did not significantly decrease. All results are expressed as mean +/- standard deviation. CONCLUSIONS: We conclude that passive leg elevation caused a worse condition in the right ventricle of group B because, with stable values of cardiac index, of systolic systemic arterial/right ventricular pressure gradient and of diastolic systemic arterial/right ventricular pressure gradient (which supply oxygen), the RVED V/P (to which oxygen consumption is inversely related) markedly decreased. This is as opposed to group A, where the cardiac index, the systolic systemic arterial/right ventricular pressure gradient and the diastolic systemic arterial/right ventricular pressure gradient increased, and the RVED V/P slightly decreased. Passive leg elevation must therefore be performed cautiously in coronary patients with a reduced RVEF.

Aged↗
PubMed1982

Studies of left-ventricular function in anemia due to beta-thalassemia.

Left-ventricular (LV) function was studied in 23 patients with anemia due to beta-thalassemia, of whom seven had thalassemia intermedia and the remainder thalassemia major. Two-thirds of the patients wih thalassemia intermedia and almost all the patients with thalassemia major were in clinical congestive heart failure. Despite this, resting measurements of ventricular size and systolic ventricular function were normal, indicating high-output cardiac failure. However, effort testing showed a flat response or decrease in the LV shortening fraction in patients with thalassemia major, and serial studies showed a decrease in the shortening fraction over a 4-yr period in some patients. LV diastolic function was studied by calculating peak LV filling rate and the pattern of LV filling in early diastole. Three patient with thalassemia major showed a pattern indicating abnormal LV distension. Since LV end-diastolic dimension was increased, volume overload was present in all patients. The results indicate that the following factors contribute to the genesis of cardiac failure in beta-thalassemia: 1) diminished response of systolic ventricular performance to exercise and later at rest; 2) ventricular volume overload; and 3) abnormal ventricular distension in diastole. Although the ventricular filling suggests abnormal LV compliance, the effect of right-ventricular volume overload or a pericardial factor cannot be excluded.

Adolescent↗
PubMed2004

Role of diastole in left ventricular function, I: Biochemical and biomechanical events.

Left ventricular diastolic function plays an important role in cardiac physiology. Lusitropy, the ability of the cardiac myocytes to relax, is affected by both biochemical events within the myocyte and biomechanical events in the left ventricle. Beta-adrenergic stimulation alters diastole by enhancing the phosphorylation of phospholamban, a substrate within the myocyte that increases the uptake of calcium ions into the sarcoplasmic reticulum, increasing the rate of relaxation. Troponin I, a regulatory protein involved in the coupling of excitation to contraction, is vital to maintaining the diastolic state; depletion of troponin I can produce diastolic dysfunction. Other biochemical events, such as defects in the voltage-sensitive release mechanism or in inositol triphosphate calcium release channels, have also been implicated in altering diastolic tone. Extracellular collagen determines myocardial stiffness; impaired glucose tolerance can induce an increase in collagen cross-linking and lead to higher end-diastolic pressures. The passive properties of the left ventricle are most accurately measured during the diastasis and atrial contraction phases of diastole. These phases of the cardiac cycle are the least affected by volume status, afterload, inherent viscoelasticity, and the inotropic state of the myocardium. Diastolic abnormalities can be conceptualized by using pressure-volume loops that illustrate myocardial work and both diastolic and systolic pressure-volume relationships. The pressure-volume model is an educational tool that can be used to demonstrate isolated changes in preload, afterload, inotropy, and lusitropy and their interaction.

Action Potentials↗
PubMed1989

The value of cine nuclear magnetic resonance imaging for assessing regional ventricular function.

Previous nuclear magnetic resonance (NMR) imaging studies to assess left ventricular function have used multiple axial planes, which are compromised by partial volume effects and are time consuming to acquire and analyze. Accordingly, an imaging approach using cine NMR and planes aligned with the true cardiac axes of the left ventricle was developed in views comparable with left ventricular cineangiography. Cine NMR imaging was used to assess regional wall motion and was validated by comparison with biplane left ventricular cineangiography. Fifty-nine patients underwent cineangiographic and NMR studies within 72 h. A poor quality NMR study precluded analysis in 4. leaving a study group of 55 patients (mean age 58 +/- 12: 17 women). Cine NMR movie loops were acquired in two long-axis planes: 1) right anterior oblique plane, parallel to the septum, and 2) four chamber orthogonal plane, perpendicular to the septum (this view is comparable to the angiographic left anterior oblique view). To assess regional wall motion, the left ventricle in both cine NMR and cineangiographic images was divided into five segments and graded on a five point grading scale from 3 for normal through 0 for akinesia and -1 for dyskinesia. Regional wall thickening was used qualitatively to aid in the analysis of wall motion. For the 275 segments compared in the right anterior oblique view, agreement was within one grade in 263 (95.6%) of 275 segments, whereas absolute agreement was observed in 171 (62%) of 275 segments. In the left anterior oblique view, of 200 segments evaluated, agreement within one grade was achieved in 184 segments (92%) and agreement was complete in 132 (66%).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗
PubMed1984

Ventricular function following mitral valve surgery: assessment using radionuclide ventriculography.

The effects of mitral valve replacement or commissurotomy on cardiac function were studied using radionuclide ventriculography in 13 patients with chronic mitral stenosis and in 8 with chronic mitral regurgitation, before and after mitral valve surgery. The stenosis resulted from rheumatic heart disease in all instances while regurgitation was due to mitral valve prolapse in three patients and rheumatic heart disease in five. Fourteen patients had a Carpentier-Edwards valve inserted and 4 a Lillehei-Kaster disc valve. Three patients with mitral stenosis had an open commissurotomy. All patients underwent supine-rest and symptom-limited exercise radionuclide ventriculography shortly before and 6 to 12 months after operation. The data obtained showed that left ventricular function remained unchanged postoperatively in patients with mitral stenosis but deteriorated in those with mitral regurgitation. Right ventricular function improved postoperatively in those with mitral stenosis but remained unchanged in patients who had regurgitation.

Adult↗
PubMed1993

[Effects of intravenous administration of nasaruplase, a plasminogen pro-activator, on left ventricular function and systemic hemodynamics in a canine model of acute myocardial infarction].

The thrombolytic effects and changes in left ventricular function after intravenous administration of nasaruplase were examined in a canine thrombus model of acute myocardial infarction. When 8 U/kg/min of nasaruplase was intravenously administered after 30 min of coronary arterial occlusion, coronary recanalization was achieved in 78.6% (11/14) of the animals with little change in plasma fibrinogen concentration. There was no further decrease in cardiac output, left ventricular ejection fraction or regional wall motion immediately after reperfusion, compared with 30 min after coronary arterial occlusion. However, all these parameters returned to pre-occlusion levels one week after reperfusion. Nasaruplase markedly reduced infarct size as well as cardiac hypertrophy following coronary arterial occlusion, demonstrating suppression of the development of ischemic myocardial damage. These results indicate that coronary thrombolytic therapy with intravenous administration of nasaruplase is useful for the treatment of acute myocardial infarction.

Animals↗
PubMed1978

Left ventricular function in tetanus: influence of therapy.

Nine patients hospitalized for tetanus were studied under the same protocol which included two haemodynamic studies with a preload trial (PLT). The first being made during therapy (diazepam barbiturate association), on the sixth day of hospitalisation, and the second one after recovery. The comparison of the results shows that before PLT the mean arterial pressuure (MAP) is significantly increased (p less than 0.05) in patients after recovery in comparison to the same patients undergoing therapy. After PLT there is no significant difference between the two groups. Lastly, the variation of the left ventricular function points under PLT shows no significant difference between patients during therapy and after recovery. These results suggest that the diazepamphenobarbital combination does not alter the left ventricular function of the patients undergoing this therapy during tetanus.

Diazepam↗
PubMed1995

[Continuous ambulatory measurement of left ventricular function by an isotopic method].

Ambulatory cardiac radionuclide monitoring is a relatively new technique of non-invasive assessment of left ventricular function. This technique, which uses a portable gamma-ray detector, enables continuous recording over a number of hours of global left ventricular ejection fraction after red cell labelling with technetium. The detector is placed in contact with the skin over the apical region in a 45 degrees left anterior oblique view. Adequate collimation enables the variations in left ventricular volume during the cardiac cycle to be quantified and the ejection fraction to be deduced without having to generate an image. The authors review this method and describe the different available systems. They may be classified in two groups as to whether the technique is limited to continuous bed-side monitoring or if used for ambulatory monitoring (the only commercially available model being the Vest). Validation studies and trials in normal subjects are envisaged. The information acquired by this new method is analysed in the different clinical fields: post-infarction, stable angina, asymptomatic coronary artery disease, hypertension. The role of this new technique in the investigation of coronary artery disease is discussed with respect to other non-invasive techniques. The limitations of the technique and the material are reviewed and possible future developments are described.

Coronary Disease↗
PubMed2003

[Effect of ACE gene polymorphism on left ventricular function in patients with type 2 diabetes].

The authors evaluated the influence of the ACE gene polymorphism on left ventricular function in patients with diabetes type 2. In a group of 23 patients left ventricular mass, global and regional systolic function of the left ventricle as well as diastolic function was assessed from transmitral flow using two-dimensional echocardiography. In a subgroup of patients with DD (n = 7) and ID genotype (n = 16), no significant differences were found in age (p = 0.19), duration of diabetes (p = 0.46), level of HbA1c (p = 0.10), cholesterol level (p = 0.18), quantitative proteinuria (p = 0.39), systolic and diastolic blood pressure (p = 0.25, p = 0.40). No association was found between insertion-deletion polymorphism of the ACE gene and observed echocardiographic parameters [left ventricular mass index (p = 0.43), EF (p = 0.46), wall motion index (p = 0.25), E wave (p = 0.14), A wave (p = 0.07), deceleration time of the E wave (p = 0.06), E/A (p = 0.07), flow propagation velocity (Vp) (p = 0.14) and E/Vp (p = 0.38)]. The presence of myocardial infarction, ischemic heart disease and hypertension had no association with ACE gene polymorphism (p = 0.53, p = 0.61 and p = 0.64). In conclusion, there is no association between ACE gene polymorphism and systolic and diastolic function of the left ventricle in this group of patients with diabetes type 2.

Aged↗
PubMed1992

Significance of preinfarction angina for preservation of left ventricular function in acute myocardial infarction.

The effect of preinfarction angina on the preservation of left ventricular function was evaluated with the use of cineventriculography in 37 patients who had either total or subtotal occlusion of the proximal left anterior descending coronary artery during the convalescent period of myocardial infarction. In 15 patients who had preinfarction angina more than 1 week before the onset of acute myocardial infarction (group A), the global left ventricular ejection fraction was 54 +/- 3% (SEM) and regional wall motion in the infarct area was 10 +/- 3%. In 10 patients who had preinfarction angina occurred within 1 week before the onset of acute myocardial infarction (group B), the left ventricular ejection fraction and regional wall motion in the infarct area were 42 +/- 3% and 1 +/- 2%, respectively. In 12 patients without preinfarction angina (group C), the left ventricular ejection fraction and regional wall motion in the infarct area were 38 +/- 3% and -1 +/- 2%, respectively. In groups B and C, both the left ventricular ejection fraction and regional wall motion in the infarct area were lower than those in group A (p less than 0.05). The collateral circulation at the onset of acute myocardial infarction was better in group A compared with groups B and C (p less than 0.05). Thus the collateral circulation, promoted by repetitive anginal episodes indicative of myocardial ischemia, causes the preservation of myocardial function.

Angina Pectoris↗
PubMed1997

Recovery of left ventricular function following early reperfusion in acute myocardial infarction: a potential role for the calcium antagonist nisoldipine.

The purpose of the present study was to test whether the administration of a vascular-selective organic calcium antagonist (nisoldipine) at the onset of early mechanical reperfusion (by coronary angioplasty) in acute myocardial infarction could prevent or attenuate postischemic stunning and enhance the recovery of left ventricular function in these patients. The study included 36 patients with anterior acute myocardial infarction who underwent an early and successful primary coronary angioplasty within 3 hours of the onset of chest pain (mean time to reperfusion = 113 +/- 37 minutes). The infarct-related artery was the left anterior descending artery in all patients. All had single-vessel disease. Baseline coronary arteriography was completed by left ventriculography. When the infarct-related artery was identified, a guidewire was placed into the target vessel and a balloon catheter was positioned in the artery. At this point all patients were administered 0.8 mg of intracoronary nitrates through the guiding catheter. Patients were then randomized. Seventeen patients (the NIT group) did not receive further treatment during the procedure, while the other 19 patients (the NIS group) received an additional 0.05 mg of intracoronary nisoldipine. Postprocedure treatment consisted of oral nitrates (80-120 mg/day) plus enalapril (10-20 mg/day) in the NIT group patients, and oral nisoldipine (20 mg/day) plus enalapril (10-20 mg/day) in the NIS group patients. The same treatment was maintained during the 6-month follow-up period. An echocardiographic study was performed at 1, 7, 30, 90, and 180 days following the procedure. Left ventriculography and coronary angiography were repeated at 1 and 180 days after the mechanical reperfusion. An exercise test was performed at 30, 90, and 180 days following primary angioplasty. Left ventriculograms and two-dimensional echocardiograms were analyzed by a computerized system that evaluated left ventricular volumes, ejection fraction, segmental wall motion, and diastolic function (from the left ventricular volume curve). Under baseline conditions, the clinical and angiographic characteristics of the patients were similar in both treatment groups. The results showed a significantly earlier recovery of left ventricular systolic and diastolic function in the NIS group patients compared with those of the NIT group. Also, exercise capacity was significantly better at 30 days in the NIS group. The findings of the present study provide further evidence that early reperfusion in acute myocardial infarction is likely to be followed by myocardial stunning. The vascular-selective organic calcium antagonist nisoldipine, administered at the onset of reperfusion, seems to attenuate postischemic stunning and to enhance the recovery of left ventricular function in this clinical subset.

Acute Disease↗
PubMed2001

Effect of the stenosis location and severity on left ventricular function after single-vessel anterior wall myocardial infarction.

BACKGROUND: The purpose of the current study was to determine how the location of the infarct-related lesion (IRL) and the degree of stenosis during the acute and chronic phases of infarction might affect left ventricular (LV) function in patients with acute anterior wall myocardial infarction. METHODS: Ninety consecutive patients with a first single-vessel anterior wall myocardial infarction (male/female ratio 75:15, mean age 60+/-9 years) underwent coronary angiography (CAG) immediately and 1 month after infarction. Patients were grouped according to IRL location (proximal [Coronary Artery Surgery Study (CASS) No. 12] or distal [CASS No. 13] to the first diagonal branch of the left anterior descending artery) and according to the severity of stenosis at 1 month (severe stenosis [IRL >75%] and mild stenosis [IRL < or =75%]). At the time of infarction and 1 month and 1 year after infarction, total wall motion index (TWMI), left ventricular end-diastolic dimension (LVDd), left ventricular end-systolic dimension (LVDs), and fractional shortening (FS) were determined. RESULTS: TWMI was greater and FS was lower for CASS No. 12 lesions than for CASS No. 13 lesions. CASS No. 12 lesions were associated with a greater LVDd at 1 year and a greater LVDs throughout 1 year of observation. The patients with mild stenoses had significant improvements in TWMI and FS over time, whereas those with severe stenoses showed no improvement. Multivariate analysis showed that the independent factors predicting left ventricular function were IRL location at CASS No. 12, initial TIMI 0-1 flow in the IRL at emergency coronary artery graft, and the presence of a severe stenosis at 1 month. CONCLUSIONS: In patients with severe stenoses at 1 month at CASS No. 12, left ventricular functional recovery is delayed and the left ventricular chamber is enlarged. In patients with CASS No. 13 lesions, left ventricular function is preserved well, regardless of the severity of residual stenosis.

Coronary Disease↗
PubMed1993

Core and peripheral temperature response to exercise in patients with impaired left ventricular function.

OBJECTIVE: Exercise induced hypotension is a specific but insensitive indicator of severe coronary artery disease. Skin blood flow is subject to control by baroreceptor mediated reflexes as well as thermoregulatory reflexes. Monitoring skin temperature or the skin to central temperature gradient may be a more sensitive indicator of impaired cardiac output response to exercise than hypotension. DESIGN AND PARTICIPANTS: Central and skin temperature changes associated with exercise were studied in 10 normal volunteers and eight patients with impaired resting ventricular function due to ischaemic heart disease. Patients exercised according to a modified Bruce protocol. The two sample independent t test was applied to compare the central and peripheral temperatures in the two groups at three minute intervals during exercise and at two minute intervals after exercise. RESULTS: A significant decrease was found in mean (1 SEM) central temperature on exercise in our patient group (98.2(0.2) degrees F to 97.2(0.3) degrees F), compared with the normal increase in central temperature (97.7(0.2) degrees F to 98.3(0.3) degrees F). Mean (1 SEM) skin temperature changes reflected the expected skin blood flow changes with exercise in normal subjects. In the patient group skin temperature declined during exercise (89.7(2.1) degrees F to 86.6(1.7) degrees F) and was significantly lower than normal from six minutes onwards. CONCLUSIONS: The abnormal peripheral temperature changes of patients with impaired resting ventricular function is an early and sensitive indicator of an abnormal haemodynamic response to exercise. It is possible that skin temperature measurement during exercise could help detect exercise induced ventricular dysfunction due to ischaemia or impaired cardiac output due to valvar heart disease.

Aged↗
PubMed1999

Evaluation of Global and Regional Right Ventricular Function Using Automated Border Detection Techniques.

Quantitative evaluation of right ventricular (RV) function remains challenging due to the complex geometry of this chamber, which precludes the use of simple geometric assumptions. Automated border detection (ABD) techniques, which provide online changes in cardiac chamber dimensions, have been predominantly used for quantitative assessment of global as well as regional left ventricular function. Recently, acoustic quantification has been validated for quantitative evaluation of global RV function, and color kinesis has been used to objectively assess systolic and diastolic regional RV function. In this article, the main studies validating ABD for the objective assessment of global RV function and the current clinical uses of this technique are reviewed. In addition, technical guidelines and limitations of ABD techniques are described, and potential applications of color kinesis for quantitative assessment of regional systolic and diastolic RV performance are detailed. ABD techniques provide new insights into right atrial and RV systolic and diastolic properties. The clinical value of these techniques in the diagnosis, prognosis, and potential guidance of therapeutic management of RV dysfunction remains to be determined.

Journal Article↗
PubMed2001

Effects of tribromoethanol anesthesia on echocardiographic assessment of left ventricular function in mice.

BACKGROUND AND PURPOSE: Pentobarbital and ketamine-xylazine anesthesia in mice result in markedly decreased left ventricular fractional shortening and cardiac output. However, to the authors' knowledge, the effect of short-acting, alcohol-based anesthesia on these parameters is unknown. METHODS: Fifteen mice (FVB/N, C57Bl/6J, A/J, n = 5 each) underwent high-resolution (15 MHz) 2-dimensional-directed M-mode echocardiography before and after undergoing 2.5% tribromoethanol anesthesia (0.01 ml/g of body weight). RESULTS: Tribromoethanol anesthesia resulted in significant heart rate slowing (29%) and left ventricular enlargement (20%), and a more modest (12%) reduction in left ventricular fractional shortening. Cardiac output was unchanged. The differences in left ventricular function between conscious and tribromoethanol studies were similar for each of the three strains of mice. CONCLUSIONS: Tribromoethanol anesthesia induced only modest effects on M-mode estimates of basal cardiac function and did not influence cardiac output. The effects to tribromoethanol anesthesia were similar among three commonly used mice strains.

Anesthesia↗
PubMed1978

Left ventricular function after myocardial infarction: relation between systolic time intervals and quantitative ischaemic ECG changes.

Twentyfour male patients with sustained myocardial infarction (MI) were studied with 12-lead ECG and systolic time intervals (STI) 5 months after the acute episode. From the ECGs were calculated the summed voltages of the R wave (sigma R), the Q wave (sigma Q), and the ST segment deviation (sigma ST). These ischaemic ECG variables were correlated with the STI parameters of left ventricular function: LVETI, PEP and PEP/LVET. Statistically significant regression equations relating the ECG changes to the STI variables were found in anterior MI, for sigma ST in the entire series, but not in inferior MI. Thus a simple and rapid inspection of the resting 12-lead ECG gives an indirect but reliable quantitative estimate of left ventricular function in patients with a sustained myocardial infarction.

Aged↗
PubMed1983

Left ventricular function in chronic aortic regurgitation.

Left ventricular performance was determined in 42 patients with moderate or severe aortic regurgitation during upright exercise by measuring left ventricular ejection fraction and volume with radionuclide ventriculography. Classification of the patients according to exercise tolerance showed that patients with normal exercise tolerance (greater than or equal to 7.0 minutes) had a significantly higher ejection fraction at rest (probability [p] = 0.02) and during exercise (p = 0.0002), higher cardiac index at exercise (p = 0.0008) and lower exercise end-systolic volume (p = 0.01) than did patients with limited exercise tolerance. Similar significant differences were noted in younger patients compared with older patients in ejection fraction at rest and exercise (both p = 0.001) and cardiac index at rest (p = 0.03) and exercise (p = 0.0005). The end-diastolic volume decreased during exercise in 60% of the patients. The patients with a decrease in volume were significantly younger and had better exercise tolerance and a larger end-diastolic volume at rest than did patients who showed an increase in volume. The mean corrected left ventricular end-diastolic radius/wall thickness ratio was significantly greater in patients with abnormal than in those with normal exercise reserve (mean +/- standard deviation 476 +/- 146 versus 377 +/- 92 mm Hg, p less than 0.05). Thus, in patients with chronic aortic regurgitation: 1) left ventricular systolic function during exercise was related to age, exercise tolerance and corrected left ventricular end-diastolic radius/wall thickness ratio, and 2) the end-diastolic volume decreased during exercise, especially in younger patients and patients with normal exercise tolerance or a large volume at rest.

Adolescent↗