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1.
Thirty-one subjects with chronic congestive heart failure (CHF) were separated into 3 groups according to ventilatory patterns during graded exercise: Group 1--oscillators (n = 6); group 2-intermediate oscillators (n = 14); and group 3--nonoscillators (n = 11). Group 1 patients showed cyclic fluctuations in minute ventilation (change of 30 to 40 liters/min) and arterial PO2 (change of 38.0 +/- 4.1 mm Hg) and PCO2 (change of 11 +/- 2.8 mm Hg). The nadir in arterial PO2 occurred at times when wasted ventilatory effort was maximal. The amplitude of ventilatory oscillations in group 1 patients increased in the transition from rest to light exercise and damped with heavy exercise. There was no evidence of alveolar hypoventilation at the nadirs of minute ventilation; arterial PCO2 was always 40 mm Hg or less. Substantial hyperventilation (ventilatory equivalent for CO2 twice normal) occurred with maximal minute ventilation in group 1 patients. Oscillatory hyperventilation correlated with severity of CHF. Maximal oxygen uptake was significantly lower in group 1 (11.7 +/- 1.1 ml/kg/min) than group 3 (17.9 +/- 1.8 ml/kg/min) (p less than 0.05). Oscillatory hyperventilation during exercise may accompany severe CHF and compounds the inadequate delivery of oxygen by the failing heart.  相似文献   

2.
Inflammatory cytokines may play a pathogenic role in the development of congestive heart failure (CHF). Elevated circulating levels of inflammatory cytokines have been reported in CHF, but most studies have focused on only a few cytokine parameters. However, the activity of these cytokines are modulated by soluble cytokine receptors and cytokines with anti-inflammatory activities, and in the present study several of these interacting factors were examined simultaneously in 38 CHF patients with various degrees of heart failure and in 21 healthy controls. Patients with CHF had increased plasma concentrations of tumor necrosis factor (TNF)alpha, interleukin-6, soluble TNF receptors and the soluble interleukin-6 receptor, glycoprotein (gp)130. They also had elevated ratios of TNFalpha/soluble TNF receptors and interleukin-6/soluble gp130 as well as enhanced interleukin-6 bioactivity in serum, suggesting inflammatory net effects. In addition to raised circulating levels of inflammatory cytokines, CHF patients with severe heart failure also had abnormalities in the levels of anti-inflammatory cytokines, with decreased levels of transforming growth factor beta1 and inadequately raised interleukin-10 in relation to the elevated TNFalpha concentrations. This dysbalance between inflammatory and anti-inflammatory cytokines was also found in monocyte supernatants from CHF patients. The abnormalities in the cytokine network were most pronounced in patients with the most severe heart failure, and several of the immunologic parameters, in particular soluble gp130, were correlated with variables reflecting deranged hemodynamic status. The present study analyzing the complexity of the cytokine network in CHF, demonstrates profound disturbances in the levels of both inflammatory and anti-inflammatory mediators with a marked dysbalance favoring inflammatory effects.  相似文献   

3.
Elevated plasma norepinephrine (PNE) has been shown to be an important predictor of morbidity and mortality in patients with congestive heart failure (CHF). Moxonidine selectively stimulates imidazoline receptors located in the medulla, which centrally inhibit sympathetic outflow. PNE is suppressed and peripheral vasodilation reduces systemic blood pressure. This study evaluated the acute neurohumoral and hemodynamic effects of a single dose of oral moxonidine in 32 patients (22 men, mean ± SD age 66 ± 10 years) with CHF. All patients were in New York Heart Association functional class III and stabilized on chronic therapy with diuretics, digitalis, and angiotensin-converting enzyme inhibitors. The mean PNE concentration was 509 ± 304 pg/ml at baseline. Patients underwent invasive hemodynamic monitoring after double-blind randomization to either placebo (n = 12), moxonidine 0.4 mg (n = 9), or moxonidine 0.6 mg (n = 11). Moxonidine produced a dose-dependent, vasodilator response compared with placebo. Analysis of the time-averaged change from baseline over 6 hours demonstrated that moxonidine 0.6 mg caused significant reductions in mean systemic arterial pressure (p <0.0001), mean pulmonary arterial pressure (p <0.005), systemic vascular resistance (p <0.05), pulmonary vascular resistance (p <0.01), and heart rate (p <0.05). Stroke volume was unchanged. PNE was reduced substantially (−180 pg/ml at 4 hours, p <0.005) and the reduction was highly correlated with the baseline level (r = −0.968). Moxonidine was well tolerated in this single-dose study and resulted in a modest, dose-dependent, vasodilator response, with substantial reductions in systemic and pulmonary arterial blood pressure. Trials designed to evaluate the clinical efficacy of chronic moxonidine therapy in CHF added to conventional therapy would be appropriate.  相似文献   

4.
Elevated plasma norepinephrine (PNE) has been shown to be an important predictor of morbidity and mortality in patients with congestive heart failure (CHF). Moxonidine selectively stimulates imidazoline receptors located in the medulla, which centrally inhibit sympathetic outflow. PNE is suppressed and peripheral vasodilation reduces systemic blood pressure. This study evaluated the acute neurohumoral and hemodynamic effects of a single dose of oral moxonidine in 32 patients (22 men, mean ± SD age 66 ± 10 years) with CHF. All patients were in New York Heart Association functional class III and stabilized on chronic therapy with diuretics, digitalis, and angiotensin-converting enzyme inhibitors. The mean PNE concentration was 509 ± 304 pg/ml at baseline. Patients underwent invasive hemodynamic monitoring after double-blind randomization to either placebo (n = 12), moxonidine 0.4 mg (n = 9), or moxonidine 0.6 mg (n = 11). Moxonidine produced a dose-dependent, vasodilator response compared with placebo. Analysis of the time-averaged change from baseline over 6 hours demonstrated that moxonidine 0.6 mg caused significant reductions in mean systemic arterial pressure (p <0.0001), mean pulmonary arterial pressure (p <0.005), systemic vascular resistance (p <0.05), pulmonary vascular resistance (p <0.01), and heart rate (p <0.05). Stroke volume was unchanged. PNE was reduced substantially (−180 pg/ml at 4 hours, p <0.005) and the reduction was highly correlated with the baseline level (r = −0.968). Moxonidine was well tolerated in this single-dose study and resulted in a modest, dose-dependent, vasodilator response, with substantial reductions in systemic and pulmonary arterial blood pressure. Trials designed to evaluate the clinical efficacy of chronic moxonidine therapy in CHF added to conventional therapy would be appropriate.  相似文献   

5.
The impact of nonsteroidal anti-inflammatory drugs (NSAIDs) on renal function has not been evaluated in patients with congestive heart failure. Therefore, the renal effects of indomethacin were examined in patients with chronic heart failure, and the relation between the changes in glomerular filtration rate and renal plasma flow after indomethacin administration was assessed. Twenty-five patients with congestive heart failure and an ejection fraction less than 40% were evaluated. At baseline, renal plasma flow and glomerular filtration rate were measured, using disappearance from the serum of intravenously injected 131I-orthodihippurate and urinary accumulation of intravenously injected technetium-99m diethylenetriamine pentaacetic acid, respectively. After 3 days, 75 mg of sustained release indomethacin were administered, and repeat renal function tests were performed. Mean glomerular filtration rate decreased from 40 +/- 21 to 32 +/- 16 ml/min/1.73 m2 (p less than 0.05), and mean renal plasma flow decreased from 242 +/- 122 to 222 +/- 110 ml/min/1.73 m2 (p less than 0.05). There was no correlation between the changes in glomerular filtration rate and renal plasma flow after indomethacin administration. It is concluded that 1 dose of an NSAID may cause marked and clinically important alterations in renal function in patients with heart failure. However, the decrease in glomerular filtration rate does not merely reflect a decrease in renal plasma flow, but probably the effects of NSAIDs on the intraglomerular actions of prostaglandins.  相似文献   

6.
This study was designed to assess the efficacy and safety of berberine for chronic congestive heart failure (CHF). One hundred fifty-six patients with CHF and >90 ventricular premature complexes (VPCs) and/or nonsustained ventricular tachycardia (VT) on 24-hour Holter monitoring were randomly divided into 2 groups. All patients were given conventional therapy for CHF, consisting of angiotensin-converting enzyme inhibitors, digoxin, diuretics, and nitrates. Patients in the treatment group (n = 79) were also given berberine 1.2 to 2.0 g/day. The remaining 77 patients were given placebo. Symptoms, a 6-minute walk test, left ventricular (LV) ejection fraction (EF), frequency and complexity of VPCs, and quality of life were assessed after 8 weeks of treatment and during a mean 24-month follow-up. After treatment with berberine, there was a significantly greater increase in LVEF, exercise capacity, improvement of the dyspnea-fatigue index, and a decrease of frequency and complexity of VPCs compared with the control group. There was a significant decrease in mortality in the berberine-treated patients during long-term follow-up (7 patients receiving treatment died vs 13 on placebo, p <0.02). Proarrhythmia was not observed, and there were no apparent side effects. Thus, berberine improved quality of life and decreased VPCs and mortality in patients with CHF.  相似文献   

7.
The acute hemodynamic response to intravenous dobutamine administration was compared with intravenous MDL 17,043 administration in 8 patients with severe, chronic congestive heart failure. Simultaneous radionuclide angiography was performed with gated equilibrium blood pool imaging to derive left ventricular volumes and ejection fraction during serial hemodynamic measurements. Six patients had an optimal dobutamine dose of 10 micrograms/kg/min; 2 others were compared at a dose of 7.5 micrograms/kg/min; comparisons with MDL 17,043 were after a 1.5-mg/kg bolus dose in all 8 patients. Dobutamine and MDL 17,043 caused significant and similar increases in cardiac index and stroke volume index. Dobutamine significantly increased heart rate and MDL 17,043 did not. MDL 17,043 significantly decreased pulmonary artery wedge, mean pulmonary artery and right atrial pressures; dobutamine did not. Dobutamine increased end-diastolic volume in 4 patients, with little concomitant decrease in wedge pressure; MDL 17,043 caused no change or a decrease in left ventricular end-diastolic volume in 5 patients, but consistently decreased wedge pressure in all. Thus, the left ventricular pressure-volume curve was displaced downward to a more favorable position after MDL 17,043 but not after dobutamine. In patients with chronic congestive heart failure, acute myocardial performance was more optimally influenced by MDL 17,043 than dobutamine administration.  相似文献   

8.
To determine which of the many clinical parameters routinely collected influence mortality in patients with congestive heart failure (CHF), 201 patients with idiopathic or ischemic dilated cardiomyopathy were prospectively followed for a 28-month study period. Mean age of the study group was 62 +/- 10 years, 60% had ischemic cardiomyopathy, and two-thirds were in New York Heart Association functional class II or III. Fifteen clinical variables were analyzed using a Cox proportional hazards model, while individual variables also were calculated for independent prognostic significance. There were 85 deaths, 26 (31%) of which were sudden cardiac deaths. Three characteristics at the study entry independently predicted an increased mortality risk: left ventricular ejection fraction, maximal oxygen uptake and ischemic cardiomyopathy. A Cox proportional hazards model showed that the combination of VO2max, S3 and the diagnosis of ischemic cardiomyopathy provided the best estimates of risk for an early death. Mortality for the low-risk group was only 5% at 6 months and 10% at 1 year. In contrast, in patients with an S3, ischemic cardiomyopathy and low maximal oxygen uptake, 6-month mortality was 24% and 36% at 1 year (p less than 0.001). Thus, these patients at high risk with left ventricular dysfunction associated with ischemic heart disease, a decreasing exercise tolerance and the development of an S3 should be strongly considered for an interventional trial with the aim of decreasing mortality.  相似文献   

9.
In this report, we showed for the first time that granulocyte-macrophage colony-stimulating factor plasma levels are elevated in patients with severe heart failure, and these levels are correlated well with neurohormonal activation and hemodynamic deterioration characterizing this syndrome.  相似文献   

10.
Pimobendan (UD-CG 115 BS) was administered orally to 23 patients with congestive heart failure (functional class IV) caused by coronary artery disease (11 patients) or idiopathic dilated cardiomyopathy (12). All patients received maintenance doses of digoxin, furosemide and warfarin. Baseline data, collected during 15 hours, stayed within a 10% range. A 10-mg oral dose of pimobendan increased the heart rate from 95 +/- 20 to 109 +/- 24 beats/min (p less than 0.003). The pulmonary artery wedge pressure decreased from 23.0 +/- 5.9 to 10.1 +/- 5.2 mm Hg (p less than 0.0001), the cardiac index increased from 1.9 +/- 0.4 to 3.3 +/- 0.7 liters/min/m2 (p less than 0.0001) and the left ventricular stroke work index increased from 2,005 +/- 927 to 3,065 +/- 1,161 ml/mm Hg/m2 (p less than 0.0001). Statistically significant improvements in hemodynamic variables were still present 10 hours after the administration of pimobendan. Most patients felt better and reported no angina or other side effect, the incidence of ventricular arrhythmias was unchanged and no electrocardiographic changes suggesting ischemia were observed. Patients with severe congestive heart failure experienced a prolonged improvement of their cardiovascular condition after a single dose of pimobendan.  相似文献   

11.
Epidemiologic studies have shown an important increase in the high mortality of patients with congestive heart failure (CHF) despite optimal medical management. Ventricular arrhythmia was recognized as the most common cause of death in this population. Electrolyte imbalance, myocardial fibrosis, left ventricular dysfunction, and inappropriate neurohumoral activation are presumed responsible for sudden cardiac death. In this study, we focused on the deleterious effects of the overproduction of aldosterone that occurs in patients with CHF. Secondary hyperaldersteronism can be part of several factors thought to be responsible for sudden cardiac death. We randomized 35 patients (32 men, aged 48 +/- 9 years) with systolic dysfunction (ejection fraction 33 +/- 5%) and New York Heart Association class III CHF secondary to dilated or ischemic cardiomyopathy into 2 groups. The treatment group received spironolactone, an aldosterone receptor antagonist, along with standard medical management using furosemide, angiotensin-converting enzyme inhibitors, and digoxin. The control group received only the standard medical treatment. Holter monitoring was used to assess the severity of ventricular arrhythmia. After 20 weeks, patients who received spironolactone had a reduced hourly frequency of ventricular premature complexes (VPCs) (65 +/- 18 VPCs/hour at week 0 and 17 +/- 9 VPCs/hour at week 16) and episodes of nonsustained ventricular tachycardia (VT) (3.0 +/- 0.8 episodes of VT/24-hour period at week 0, and 0.6 +/- 0.3 VT/24-hour period at week 16). During monitored treadmill exercise, a significant improvement in ventricular arrhythmia was found in the group receiving spironolactone (39 +/- 10 VPCs at week 0, and 6 +/- 2 VPCs at week 16). These findings suggest that aldosterone may contribute to the incidence of ventricular arrhythmia in patients with CHF, and spironolactone helps reduce this complication.  相似文献   

12.
To determine whether oral milrinone therapy has an effect on complex ventricular arrhythmias in patients with severe congestive heart failure and, if so, whether a change in the severity of complex ventricular arrhythmias after 1 week of milrinone therapy is associated with a change in the mode or frequency of cardiac mortality, a retrospective analysis was performed to determine the frequency of ventricular tachycardia and the density of ventricular couplets on 24-hour ambulatory electrocardiographic recordings performed before and 1 week after initiation of oral milrinone therapy in 74 consecutive patients with New York Heart Association functional class III or IV congestive heart failure. The endpoints of mortality and mode of death were assessed during a mean follow-up of 6 months. In 91% of the patients, 1 week of oral milrinone therapy was associated with no significant change (85%) or a significant decrease (6%) in the density of ventricular couplets and frequency of ventricular tachycardia. However, in 9% of patients the frequency of complex ventricular arrhythmias increased significantly at the end of 1 week of oral milrinone therapy. In this subgroup, neither total cardiac mortality nor the incidence of sudden cardiac death was significantly higher than that in patients with no change or a decrease in complex ventricular ectopic activity.  相似文献   

13.
Irregular breathing occurs frequently in patients with congestive heart failure (CHF) both during daytime and nighttime. Many factors are involved in the genesis of these breathing abnormalities, but the role of the hemodynamic impairment remains controversial. This study investigated the relation between worsening ventricular function and the frequency of respiratory disorders in patients with mild to severe CHF. One hundred fifty patients with CHF (mean age 53 +/- 8 years, left ventricular (LV) ejection fraction 26 +/- 7, in New York Heart Association [NYHA] classes II to IV, and who underwent stable therapy for > or =2 weeks) were studied. Analysis of instantaneous lung volume signal and arterial oxygen saturation during awake daytime revealed a normal respiratory pattern in 63 patients, whereas 87 had a persistent alteration of breathing, with a typical Cheyne-Stokes respiration (CSR) in 42 and periodic breathing (PB [oscillation of tidal volumes without apnea]) in 45 patients. Patients with PB and CSR showed a more pronounced hemodynamic impairment with a significantly reduced cardiac index, an increased pulmonary arterial wedge pressure, and a longer lung-to-ear circulation time (LECT) compared with patients with normal respiratory patterns. In a logistic regression model that included all of the variables significantly associated with breathing disorders, cardiac index and LECT emerged as the major determinants of CSR. In those patients with LECT > or =30 seconds (upper quartile) and cardiac index < or =1.9 L/min/m2 (lower quartiles), the incidence of CSR was significantly higher (69%) than in patients with lower LECT and higher cardiac index (14%, p <0.001). In conclusion, abnormalities of breathing activity during daytime are significantly associated with a prolonged circulation time and a more severe impairment of systolic and diastolic LV indexes.  相似文献   

14.
15.
The systemic and coronary hemodynamic and neurohumoral effects of nisoldipine, a calcium antagonist drug with high vascular specificity, were investigated in 17 patients with chronic congestive heart failure (CHF). Brachial artery infusions (n = 9) decreased forearm vascular resistance in a dose-dependent manner, attesting to its powerful arterial vasodilator properties. A dose of 3 micrograms/kg intravenously decreased mean blood pressure 16% and systemic vascular resistance 33%, while increasing stroke index 19% and ejection fraction 21% at rest and similarly during exercise. Pulmonary capillary wedge pressure decreased significantly during exercise. Intravenous infusion of nisoldipine increased rest coronary sinus flow 10% (p less than 0.05, n = 7), decreased rest and exercise coronary vascular resistance 28% and 19% (p less than 0.01) and rest myocardial oxygen consumption 14% (p less than 0.05). In 13 patients similar systemic hemodynamic results were found after treatment with oral nisoldipine, 2 X 20 mg for 4 weeks. Stroke index and stroke work index increased long-term more than acutely (31% and 12.4% vs 19% and 4.5% at rest, both p less than 0.05), which may indicate a compensated mild cardiodepressant effect of intravenous nisoldipine. Changes in forearm vascular resistance after intra-arterial administration did not correlate with changes of systemic vascular resistance after intravenous administration, suggesting that factors other than vascular calcium entry blockade importantly influence hemodynamic responses. Elevated control plasmas norepinephrine and renin levels, on average, did not change during chronic therapy but individual changes were compatible with a reduction of sympathetic activity in patients with hemodynamic improvement.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

16.
Patients with congestive heart failure (CHF) have impaired peripheral vasodilation during exercise. Hyperosmolality is one local stimulus that produces vasodilation during exercise in normal subjects. This study addressed the hypothesis that vasodilation to hyperosmolal stimuli is impaired in patients with CHF. Forearm blood flow responses to intrabrachial artery infusions of isoosmolar (280 mosm/kg) and hyperosmolal (480 and 660 mosm/kg) solutions of saline and glucose were compared in 9 patients with CHF and 13 normal subjects. Forearm blood flow was measured by strain gauge plethysmography. In the normal subjects, hyperosmolal infusions of 480 and 660 mosm/kg increased forearm blood flow by 3.12 +/- 0.40 and 6.80 +/- 0.67 ml/min/100 ml forearm volume, respectively (both p < 0.001 compared with isoosmolal infusions). In contrast, in the patients with CHF, these infusions increased forearm blood flow by 2.19 +/- 0.44 and 4.06 +/- 0.92 ml/min/100 ml forearm volume (p < 0.05 normal vs CHF). The impaired forearm blood flow responses in heart failure occurred despite significantly greater (p < 0.05, normal vs CHF) increases in venous osmolality (17.3 +/- 6.5 vs 9.6 +/- 1.3 mosm/kg for the 660 mosm/kg infusion). There were no differences between groups in forearm venous hematocrit, calcium, and sodium or potassium changes during hyperosmolal infusions. It is concluded that peripheral vasodilation to hyperosmolal stimuli is impaired in patients with CHF.  相似文献   

17.
Tumor necrosis factor-alpha (TNF-alpha) has been implicated in the pathogenesis of congestive heart failure and may be associated with an increase in mortality. A recent in vitro study showed that amiodarone decreases TNF-alpha production by human blood mononuclear cells in response to lipopolysaccharide. However, no previous clinical studies have determined the effect of chronic amiodarone therapy on TNF-alpha levels. Thus, the purpose of this study was to determine whether amiodarone affects TNF-alpha levels in patients with ischemic and nonischemic cardiomyopathy. TNF-alpha levels were analyzed by an enzyme-linked immunoassay using plasma samples at baseline, 1, and 2 years of follow-up in New York Heart Association class III patients (n = 40 in each of the placebo and amiodarone groups, mean ejection fraction 0.25+/-0.09) who were randomized in the Congestive Heart Failure-Survival Trial of Antiarrhythmic Therapy, a multicenter, double-blind, placebo-controlled study in which the effect of amiodarone on survival was investigated. TNF-alpha levels were elevated in both groups of patients at baseline, 6.6+/-3.1 and 7.7+/-5.3 pg/ml in the amiodarone and placebo groups, respectively (p = 0.3). There were no significant differences in demographic or clinical variables between the 2 groups. Amiodarone treatment was associated with a significant increase in TNF-alpha levels in patients with ischemic cardiomyopathy, 12.7+/-12.5 and 6.8+/-3.7 pg/ml in the amiodarone and placebo groups, respectively (p = 0.03) at 1 year. No change in TNF-alpha levels was observed in patients with nonischemic cardiomyopathy. In contrast to the in vitro data, amiodarone treatment is associated with an increase in TNF-alpha levels in patients with ischemic cardiomyopathy. This increase is not associated with an adverse effect on survival.  相似文献   

18.
Nine patients with chronic, severe (New York Heart Association class III to IV) congestive heart failure were studied to determine the acute effects of 10 mg of sublingual nifedipine on left ventricular (LV) function. Hemodynamic and echocardiographic data were obtained at rest and 30 minutes, 1, 2, 4 and 6 hours after nifedipine. Measurements at rest reflected LV dysfunction with elevation of end-diastolic volume index (102 +/- 46 ml/m2), pulmonary capillary wedge pressure (17 +/- 8 mm Hg), systemic vascular resistance (1,547 +/- 439 dynes s cm-5) and reduction of cardiac index (2.8 +/- 0.5 liters/min/m2). There were no adverse effects noted with administration of sublingual nifedipine. Initial changes through 1 hour reflected an unloading effect of nifedipine with reduction in pulmonary capillary wedge pressure (11 +/- 5 mm Hg) (p less than 0.05), systemic vascular resistance (1,179 +/- 289 dynes s cm-5) (p less than 0.01), end-diastolic volume index (91 +/- 37 ml/m2 [difference not significant]) and an increase in cardiac index (3.6 +/- 0.7 ml liters/min/m2) (p less than 0.01). Subsequently the cardiac index, systemic vascular resistance and end-diastolic volume index returned toward baseline. Only the pulmonary capillary wedge and pulmonary artery pressures demonstrated a sustained reduction through the 6-hour study period suggesting an effect of nifedipine on LV relaxation. Thus, sublingual nifedipine administered acutely to patients with clinical congestive heart failure is a safe and efficacious vasodilator.  相似文献   

19.
The hemodynamic effects of pacing in patients with congestive heart failure (CHF) remain controversial. Early studies reported that pacing from the right ventricular (RV) apex improved acute hemodynamic parameters in patients with left ventricular systolic dysfunction, but these findings were not confirmed in subsequent controlled studies. More recently, it has been proposed that pacing from the RV side of the ventricular septum improves hemodynamic function compared with intrinsic conduction or apical pacing. Either dual-chamber or ventricular pacing have been evaluated, again with inconsistent findings. To assess the effects of pacing site and mode on acute hemodynamic function, we evaluated 21 subjects with CHF and intrinsic conduction disease. Hemodynamics were compared in AAI, VVI, and DDD modes with pacing from the RV apex or high septum. The pacing rate was constant in each patient and the order of testing was randomized. In the absence of ventricular pacing (AAI mode), the mean systemic arterial pressure was 85 +/- 11 mm Hg, the right atrial pressure was 11 +/- 4 mm Hg, the pulmonary capillary wedge pressure was 18 +/- 8 mm Hg and the cardiac index was 2.4 +/- 0.7 L/min/m(2). Compared with AAI pacing, there were no improvements in any hemodynamic parameter with DDD pacing from either RV site. Hemodynamic function worsened with VVI pacing from both RV sites. Subgroup analyses of patients with dilated cardiomyopathy, with prolonged PR interval, or with significant mitral regurgitation also failed to demonstrate an improvement with pacing. We conclude that pacing mode but not RV pacing site affects acute hemodynamic function. Pacing in the DDD mode prevents the deleterious effects of VVI pacing in this patient population.  相似文献   

20.
The usefulness of systolic time intervals, diastolic time intervals and echocardiography in evaluating left ventricular (LV) function was determined in 69 patients with severe congestive heart failure. All systolic time intervals were markedly abnormal (preejection period/LV ejection time 0.59 +/- 0.18 vs 0.30 +/- 0.04, preejection period index 170 +/- 37 vs 117 +/- 11, LV ejection time index 372 +/- 26 vs 410 +/- 17; patients vs control subjects, p less than 0.05). Diastolic time intervals in patients were not different from those in control subjects. Echocardiographic measurements were all markedly abnormal (LV end-diastolic dimension 6.9 +/- 1.0 vs 4.8 +/- 0.4 cm, patients vs control subjects, p less than 0.05). No pattern of abnormalities distinguished ischemic cardiomyopathies from idiopathic dilated cardiomyopathies. The presence of LV conduction delay did not substantially alter results, except that exclusion of patients with LV conduction delay normalized the total time of systole (QA2) index (from 542 +/- 40 to 531 +/- 31 ms) and reduced but did not normalize prolongation in the preejection period index (from 170 +/- 37 to 162 +/- 29 ms). No systolic or diastolic interval strongly correlated with any hemodynamic or other independent measure of LV performance. Twenty-four patients were given inotropic or unloading agents, which significantly improved hemodynamic values. Systolic and diastolic intervals were measured at baseline and at maximal hemodynamic effect. The correlation of changes in hemodynamics with changes in systolic and diastolic intervals was only modest. Thus, although systolic time intervals and associated echocardiographic measurements can detect abnormal LV function, they cannot reliably detect a change in LV function or distinguish gradations of abnormality.(ABSTRACT TRUNCATED AT 250 WORDS)  相似文献   

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