Left Ventricular Performance In Patients Research Articles

Variants of Toll-like Receptor 4 Predict Cardiac Recovery in Patients with Dilated Cardiomyopathy

The clinical course of patients with dilated cardiomyopathy (DCM) varies from cardiac recovery to end stage heart failure. The etiology of this variability is largely unknown. In this study, we investigated the impact of coding polymorphisms of the innate immune protein Toll-like receptor 4 (TLR4) on left ventricular performance in patients with DCM. Two variants of TLR4 (rs4986790, TLR4 c.1187A→G, p.299D→G and rs4986791,TLR4 c.1487C→T, p.T399I) were investigated in 158 patients with DCM. Other reasons for heart failure were excluded by coronary angiography, myocardial biopsy, and echocardiography. Risk factors, age, gender, or treatment did not differ among the groups. At the follow-up evaluation (median 4.0-5.4 months), patients carrying the TLR4 wild type gene displayed cardiac recovery under intense medical heart failure therapy indexed by reduced left ventricular dilation, improved left ventricular ejection fraction, and reduced NT-probrain natriuretic peptide blood level when compared with the initial evaluation. In contrast, patients carrying both the rs4986790 and the rs4986791 variant showed significantly reduced improvement of left ventricular ejection fraction (p = 0.006) and left ventricular dilation (p = 0.015) at the follow-up evaluation when compared with carriers of the wild type gene under the same treatment conditions. In addition, NT-probrain natriuretic peptide level in carriers of both TLR4 variants did not change significantly at the follow up when compared with the first evaluation. Among patients with DCM, the presence of the TLR4 variants rs4986790 and rs4986791 predicts impaired cardiac recovery independently of medical treatment or cardiac risk factors.

The Incremental Value of Valvuloarterial Impedance in Evaluating the Results of Transcatheter Aortic Valve Implantation in Symptomatic Aortic Stenosis

Valvuloarterial impedance (Z(va)) can estimate the global hemodynamic load on the left ventricle in patients with severe aortic stenosis better than the standard indexes, as shown in previous studies. In fact, Z(va) can estimate global left ventricular hemodynamic load as the sum of valvular and vascular loads. The aim of this study was to evaluate the acute improvement of left ventricular performance in patients with symptomatic aortic stenosis after transcatheter aortic valve implantation (TAVI) using Z(va). One hundred two consecutive patients who underwent TAVI were submitted to transthoracic echocardiography immediately before and after aortic valve implantation, together with invasive hemodynamic measurements. After TAVI, immediate reductions in the transaortic peak pressure gradient (P < .0001) and mean pressure gradient (P < .0001) and a concomitant increase in aortic valve area (P < .0001) were seen on echocardiography. Left ventricular ejection fraction significantly increased immediately after TAVI in all patients (from 48.9 ± 10.3% to 52.1 ± 11.1%, P < .0001). Regarding global left ventricular hemodynamic load, acute and significant reductions in end-systolic meridional wall stress (from 82.7 ± 42.6 to 57.8 ± 30.1 kdyne · cm(-2), P < .0001) and in Z(va) (from 6.81 ± 2.51 to 5.38 ± 2.13 mm Hg · mL(-1) · m(-2), P < .0001) were observed. Furthermore, patients who died at 6-month follow-up had higher baseline Z(va) values compared with those who were alive at 6-month follow-up (8.13 ± 3.08 vs 6.41 ± 2.12 mm Hg · mL(-1) · m(-2), P < .004). TAVI is characterized by an immediate enhancement of global left ventricular hemodynamic performance, as demonstrated by an acute Z(va) improvement, even in patients with low baseline ejection fractions.

Abstract P64: Right Ventricular Outflow Septal Pacing as Cardiac Resynchronization Therapy in Patients with Right Bundle-Branch Block: Results in 62 Patients

Background: Cardiac resynchronization therapy has been shown to improve left ventricular performance in patients with left ventricular dysfunction and a left-sided interventricular conduction delay. This is performed by placing a pacing lead on the lateral left ventricular wall to stimulate the area normally stimulated by the left bundle branch. In patients with right bundle branch block (RBBB), pacing the right bundle branch could also result in resynchronization. Previous studies have shown that right ventricular outflow septal (RVOS) pacing does, in fact, utilize the native conduction system. Methods: 62 consecutive patients, 46 male/16 female, aged 75 +/− 10.5 yr, with RBBB and indications for pacing, underwent RVOS lead placement using commercially available pacing systems. The patients subsequently underwent bedside A-V optimization to achieve the narrowest QRS duration and most “normal” QRS complex. Echocardiography was performed to evaluate changes in wall motion comparing baseline with optimal pacing. Results: Baseline mean QRS duration 146 +/− 20.9 ms Optimized mean QRS duration 111 +/− 20.5 ms Average decrease in QRS duration -35 +/− 21.5 ms p &lt; 0.001 Echocardiography demonstrated improvement in septal contraction abnormalities. Conclusions: 1) RVOS pacing in RBBB patients can significantly narrow the QRS complex on ECG. 2) Septal contraction abnormalities due to RBBB can be improved with RVOS pacing and optimal A-V timing. 3) Further studies are warranted to evaluate this therapy in a heart failure population.

Novel Area Strain Based on Three-Dimensional Wall Motion Analysis for Assessment of Global Left Ventricular Performance after Repair of Tetralogy of Fallot

This study aimed to determine the usefulness of novel parameters of left ventricular (LV) endocardial area strain (AS) in assessing global LV performance in patients with repaired tetralogy of Fallot (TOF). Thirty patients, aged 21.7 ± 5.8 years, with repaired TOF and 25 healthy subjects aged 19.9 ± 5.5 years were studied. Three-dimensional LV wall motion tracking was performed to determine global and regional peak AS, an AS-systolic dyssynchrony index (SDI), and LV volumes and ejection fraction. The AS-SDI was derived from the dispersion of time-to-minimum segmental endocardial areas, expressed as a percentage of RR interval, using a 16-segment model. The LV global performance plot was generated by plotting peak global AS against AS-SDI. The coefficients of variations for intra- and interobserver measurement of LV global AS were 6.3% and 10.6%, respectively. Compared with controls, patients had significantly lower global AS (30.5% ± 4.5% vs. 40.9% ± 2.8%, P < .001) and greater AS-SDI (10.0% ± 2.9% vs. 4.1% ± 1.4%, P < .001). Global AS (r= 0.94, P < .001) and AS-SDI (r= -0.76, P < .001) correlated strongly with LV ejection fraction. The global performance plot identified 87% of patients (26/30) with both reduced LV global AS and LV systolic mechanical dyssynchrony. AS measurement of LV endocardium based on three-dimensional wall motion tracking is reproducible and enables convenient assessment of global LV performance using a composite representation of parameters, including global AS and an AS-derived index of mechanical dyssynchrony.

Conventional and segmental myocardial Tei indices measurement in patients with acute ST-segment elevation myocardial infarction: Is there a relation?

Background: Myocardial infarction (MI) results in impairment of left ventricular (LV) systolic and diastolic functions to various degrees. The tissue Doppler image derived Tei index (TDI-Tei index) has recently been used to assess LV function, and like the conventional Tei index, it was also found to be useful for global function. There are a small number of studies which apply TDI-Tei index to assess regional function and whether it varies according to the degree of changes in wall motion in various LV segments. Objectives: This study was conducted to assess the changes of segmental myocardial Tei index by TDI according to the degree of changes of wall motion in the patient with acute ST-segment elevation myocardial infarction (STEMI) and its correlation with Tei index derived by conventional Doppler. Patients and methods: This study was carried out on thirty patients with acute STEMI selected from Coronary Care Unit, Cardiology Department, Mansoura Specialized Hospital, Mansoura University, Egypt. The study group was subjected to clinical assessment, electrocardiography (ECG), routine laboratory profile and Doppler echocardiography (conventional and pulsed wave tissue Doppler imaging “PW-TDI”). Tei index was calculated from the sum of isovolumetric contraction time (IVCT) and isovolumetric relaxation time (IVRT), divided by ejection time (ET) which were measured from pulsed wave Doppler imaging of the trans-mitral inflow and LV outflow tracts. Myocardial velocities and TDI-Tei index were measured at basal and mid-segments of LV walts from apical 4, 2 and 5-chamber views using 16-segment model. Average values of myocardial velocities and TDI-Tei indices were obtained from normal, hypokinetic and akinetic segments then compared. Results: The mean values of left ventricular ejection fraction (LVEF), mitral E/A ratio and conventional Tei index were 51.83 ± 5.15%, 1.18 ± 0.15 and 0.63 ± 0.07 ms, respectively. Segmental myocardial TDI-Tei index was correlated positively with conventional Tei index ( r = 0.648, P < 0.001). TDI-Tei indices were significantly higher in akinetic and hypokinetic segments than those of normal segments (0.70 ± 0.09, 0.64 ± 0.05 vs 0.63 ± 0.05, P < 0.001). Conclusions: Tei index (either conventional or TDI) is superior to EF in evaluation of LV performance in patients with acute STEMI. Tei index derived by myocardial segments by TDI is correlated with conventional Tei index. Segmental TDI-Tei index values differ according to the grade of dysfunctional wall motion.

The Use of Nitroprusside in the Treatment of Acute Myocardial Infarction

In 15 patients with acute myocardial infarction, intravenous infusion of the potent vasodilator, nitroprusside, produced an average 50% fall in the elevated left ventricular filling pressure and a modest reduction in arterial pressure (average, 15.5%) without a change in heart rate. Careful dose adjustment in several patients resulted in a significant fall in left ventricular filling pressure with little or no change in arterial pressure. Cardiac output consistently rose during nitroprusside infusion in patients with clinical signs of left ventricular failure or shock and low control cardiac output, whereas output changed little on those patients with normal cardiac index. A fall in pressure time per minute as well as the fall in left ventricular filling pressure indicated a reduction in myocardial oxygen consumption during the vasodilator infusion. Drug infusion was usually accompanied by subjective improvement, including relief of dyspnea and of chest pain, and reduction in ventricular irritability. These data suggest, that vasodilator therapy, by reducing left ventricular afterload, can improve left ventricular performance in patients with acute myocardial infarction. Such treatment may be a rational approach to the management of patients with heart failure, pulmonary edema, or early shock. 1 Commentary Until the publication of this manuscript, little attention was given to the reduction of the peripheral vascular resistance as a method of improving left ventricular function in patients with acute myocardial infarction. The concern about using vasodilators were either that reducing blood pressure will decrease coronary blood flow or because physicians were concerned that a decrease in blood pressure was associated with clinical deterioration. However, Dr Cohn and his colleagues hypothesized that increases in blood pressure in a failing ventricle is harmful and therefore a control decrease in blood pressure may be expected to decrease left ventricular filling pressure. This is the reason why they used nitroprusside in infusion rates between 30 lg ⁄min and 150 lg ⁄min to control blood pressure in these patients and demonstrated a striking fall in left ventricular filling pressure with very little decrease in blood pressure. They also caution that if patients are hypotensive, one should be careful. In this manuscript, the authors put forth a possible mechanism for why nitroprusside may be beneficial to these patients in decreasing left ventricular afterload more than left ventricular preload. In addition, they suggested that compared with inotropic agents, using nitroprusside in patients with acute myocardial infarction reduced left ventricular oxygen consumption. Finally, the authors conclude that nitroprusside may be beneficial in patients with acute pulmonary edema and those with heart failure or early shock. The next historical vignette will discuss the use of nitroprusside in the treatment of refractory heart failure.

Consequences of a hypertensive right ventricle on left ventricular performance of patients with pulmonary atresia and intact ventricular septum after right heart bypass surgery

A hypertensive right ventricle adversely affects left ventricular function in patients who are Fontan candidates with pulmonary atresia with intact ventricular septum (PAIVS). Decompression of a hypertensive right ventricle should improve left ventricular performance. Recently, a right ventricular outflow tract reconstruction, the closed Brock procedure, and/or percutaneous balloon pulmonary valvuloplasty were performed to decompress the hypertensive right ventricle before and during the bidirectional Glenn procedure in Fontan-candidate patients with PAIVS in our hospital. This strategy significantly improved left ventricular performance (contractility and ventricular efficiency) after the bidirectional Glenn procedure and a staged total cavopulmonary connection.

Impact of intravenous immunoglobulin infusion on longitudinal left ventricular performance in patients with acute Kawasaki disease of usual course

To determine the acute change in cardiac performance after intravenous immunoglobulin infusion (IVIG) in patients with acute Kawasaki disease (KD). Subjects were 33 patients with KD who were treated with IVIG 2 g/kg and recovered without coronary artery lesion and 27 controls. Subjects underwent combined two-dimensional, Doppler, and tissue Doppler echocardiographic (TDI) studies. In KD, these echocardiographic studies were performed before IVIG, 48 h after IVIG, and in convalescence. Echocardiographic variables were compared between KD and controls as well as among 3 time points in KD. Before IVIG, KD showed significantly higher peak aortic velocity and shorter aortic ejection time as results of tachycardia and significantly lower E' (p<0.04) but significantly higher E/E' (p<0.02). After IVIG, patients with KD became afebrile and showed significantly lower TDI indices such as S', E', and, A' and isovolumic acceleration (IVA) (163+/-56 vs. 208+/-70 cm/s(2), p<0.01) with higher TDI-derived Tei index (0.50+/-0.10 vs. 0.44+/-0.06, p<0.02) than controls. These differences tended to disappear in convalescence. In analysis of repeated measurements, except for hemodynamic changes associated with tachycardia, S' (7.9+/-1.3 vs. 7.0+/-1.1 vs. 7.4+/-0.9 cm/s, p<0.001), IVA (227+/-72 vs. 163+/-56 vs. 180+/-63, p<0.05), and A' (7.7+/-3.0 vs. 5.6+/-1.3 vs. 6.7+/-2.3 cm/s, p<0.001) were significantly different among these time points. In patients with acute KD with usual course, IVIG induced transient sub-clinical longitudinal left ventricular dysfunction.

Relationship between serum matrix metalloproteinases in the coronary sinus and left ventricular performance in patients with nonischemic dilated cardiomyopathy

Background: Recent studies have shown that circulating matrix metalloproteinases (MMPs) are closely associated with left ventricular (LV) remodeling and adverse cardiac events in patients with nonischemic dilated cardiomyopathy (DCM). We aimed to evaluate the relationship between serum profiles of MMPs in the coronary sinus (CS) and the LV performance in patients with DCM. Methods: We measured serum levels of MMP-2, MMP-3, and MMP-9 in the aortic root (Ao) and the CS using ELISA in 45 patients with DCM.

Right Ventricular Outflow Septal Pacing as Cardiac Resynchronization Therapy in Patients with Right Bundle Branch Block – Results in 50 Patients

Background: Cardiac resynchronization therapy has been shown to improve left ventricular performance in patients with left ventricular dysfunction and a left-sided interventricular conduction delay. This is performed by placing a pacing lead on the lateral left ventricular wall to stimulate the area normally stimulated by the left bundle branch. In patients with right bundle branch block (RBBB), pacing the right bundle branch could also result in resynchronization. Previous studies have shown that right ventricular outflow septal (RVOS) pacing does, in fact, utilize the native conduction system. Methods: 53 consecutive patients, 42 male/11 female, aged 75 ± 10.8 yr, with RBBB and indications for pacing underwent RVOS lead placement using commercially available pacing systems. The patients subsequently underwent bedside A-V optimization to achieve the narrowest QRS duration and most “normal” QRS complex. Echocardiography was performed to evaluate changes in wall motion comparing baseline with optimal pacing. Results:Baseline mean QRS duration 145 ± 18.1 msOptimized mean QRS duration 110 ± 20.7 msAverage Optimal AV Delay 205 ± 45.9 msAverage decrease in QRS duration 34 ± 21.4 msp < 0.001Echocardiography demonstrated improvement in septal contraction abnormalities.Conclusions: 1) RVOS pacing in RBBB patients can significantly narrow the QRS complex on ECG. 2) Septal contraction abnormalities due to RBBB can be improved with RVOS pacing and optimal A-V timing. 3) Further studies are warranted to evaluate this therapy in a heart failure population.

Biventricular pacing preserves left ventricular performance in patients with high-grade atrio-ventricular block: a randomized comparison with DDD(R) pacing in 50 consecutive patients

We aimed to investigate whether biventricular (BiV) pacing minimizes left ventricular (LV) dyssynchrony and preserves LV ejection fraction (LVEF) as compared with standard dual-chamber DDD(R) pacing in consecutive patients with high-grade atrio-ventricular (AV) block. Fifty patients were randomized to DDD(R) pacing or BiV pacing. LVEF was measured using three-dimensional echocardiography. Tissue-Doppler imaging was used to quantify LV dyssynchrony in terms of number of segments with delayed longitudinal contraction (DLC). LVEF was not different between groups after 12 months (P = 0.18). In the DDD(R) group LVEF decreased significantly from 59.7(57.4-61.4)% at baseline to 57.2(52.1-60.6)% at 12 months of follow-up (P = 0.03), whereas LVEF remained unchanged in the BiV group [58.9(47.1-61.7)% at baseline vs. 60.1(55.2-63.3)% after 12 months (P = 0.15)]. Dyssynchrony was more prominent in the DDD(R) group than in the BiV group at baseline (2.2 +/- 2.2 vs. 1.4 +/- 1.3 segments with DLC per patient, P = 0.10); and at 12 month follow-up (1.8 +/- 1.9 vs. 0.8 +/- 0.9 segments with DLC per patient, P = 0.02). NT-proBNP was unchanged in the DDD(R) group during follow-up (122 +/- 178 pmol/L vs. 91 +/- 166 pmol/L, NS) but decreased significantly in the BiV-group (from 198 +/- 505 pmol/L to 86 +/- 95 pmol/L after 12 months, P = 0.02). BiV pacing minimizes LV dyssynchrony, preserves LV function, and reduces NT-proBNP in contrast to DDD(R) pacing in patients with high-grade AV block.

Isolated Left Ventricular Diastolic Dysfunction: Implications for Exercise Left Ventricular Performance in Patients Without Congestive Heart Failure

Clinical relevance of left ventricular (LV) diastolic dysfunction in the absence of congestive heart failure (CHF) and LV systolic dysfunction is not fully established. Asymptomatic outpatients, sedentary, with cardiovascular risk factors but no history of cardiovascular events, underwent echocardiographic evaluation of LV structure and function by standard Doppler, color M-mode, and Doppler tissue methods, and exercise testing with simultaneous noninvasive assessment of LV stroke index and cardiac index. LV ejection fraction less than 50% and significant valvular disease or stress test suggestive of coronary disease were additional exclusion criteria. In 70 patients selected (40 +/- 10 years old, 63% men, 34% hypertensive, 34% diabetic, 4% diabetic and hypertensive, 11% with LV hypertrophy), LV diastolic dysfunction was detected in 26%, which was associated with hypertension, higher LV mass index, lower systolic function, lower peak exercise heart rate, and chronotropic reserve (all P < .05), and with lower peak exercise stroke index and cardiac index (both covariates adjusted P < .05), but not with lower peak exercise metabolic equivalents (P > .5). Abnormal LV relaxation was independently correlated with lower peak exercise cardiac index and stroke index (both P < .05). Peak exercise systolic and cardiac indices were comparable between patients with CHF risk factors (74%) versus those without. Isolated LV diastolic dysfunction was independently associated with lower peak exercise LV systolic performance in patients without CHF. Its diagnosis may provide a target for aggressive CHF risk management.

Long-Term Vasodilator Therapy in Patients with Severe Aortic Regurgitation

Vasodilator therapy can reduce the left ventricular volume and mass and improve left ventricular performance in patients with aortic regurgitation. Accordingly, it has been suggested that such therapy may reduce or delay the need for aortic-valve replacement. We randomly assigned 95 patients with asymptomatic severe aortic regurgitation and normal left ventricular function to receive open-label nifedipine (20 mg every 12 hours), open-label enalapril (20 mg per day), or no treatment (control group) to identify the possible beneficial effects of vasodilator therapy on left ventricular function and the need for aortic-valve replacement. After a mean of seven years of follow-up, the rate of aortic-valve replacement was similar among the groups: 39 percent in the control group, 50 percent in the enalapril group, and 41 percent in the nifedipine group (P=0.62). In addition, there were no significant differences among the groups in aortic regurgitant volume, left ventricular size, left ventricular mass, mean wall stress, or ejection fraction. One year after valve replacement, the left ventricular end-diastolic diameter and end-systolic diameter had decreased to a similar degree among the patients who underwent surgery in each of the three groups, and all the patients had a normal ejection fraction. Long-term vasodilator therapy with nifedipine or enalapril did not reduce or delay the need for aortic-valve replacement in patients with asymptomatic severe aortic regurgitation and normal left ventricular systolic function. Furthermore, such therapy did not reduce the aortic regurgitant volume, decrease the size of the left ventricle, or improve left ventricular function.

Utility of myocardial performance index measured by left ventricular catheterization

Background — Myocardial performance index (MPI) is a valuable index of global ventricular performance. It is almost always measured by Doppler echocardiography. The purposes of this study were (1) to compare MPI measured by catheterization (MPIc) and that measured by Doppler echocardiography (MPId), and (2) to compare it with the functional status.Materials and methods — The study included 80 patients who had undergone left heart catheterization. The MPIc was measured from the pressure recordings obtained at left ventricle and aorta.Results — Mean MPId and MPIc were 0.40 ± 0.12 and 0.42 ± 0.12, respectively. Mean left ventricular end diastolic pressure (LVEDP) was 13 ± 5 mm Hg. Mean heart rate was 77 ± 11 beats/min. Mann-Whitney U test revealed that MPIc could discriminate between the functional statuses of the patients. The regression analysis revealed that there is a good correlation between MPIc and MPId, LVEDP or heart rate.There was no significant difference between MPIc and MPId (p > 0.05).Conclusion — The present data show that (1) the MPIc has a strong correlation with MPId; (2) it is a good discriminator of functional status. It may provide an additional information regarding the left ventricular performance in patients who underwent the cardiac catheterization.

Effects of perindopril on cardiac sympathetic nerve activity in patients with congestive heart failure: comparison with enalapril

The production of aldosterone in the heart is suppressed by the angiotensin-converting enzyme (ACE) inhibitor perindopril in patients with congestive heart failure (CHF). Moreover, perindopril has been reported to have more cardioprotective effects than enalapril. Forty patients with CHF [left ventricular ejection fraction (LVEF) <45%; mean 33+/-7%] were randomly assigned to perindopril (2 mg/day; n = 20) or enalapril (5 mg/day; n = 20). All patients were also treated with diuretics. The delayed heart/mediastinum count (H/M) ratio, delayed total defect score (TDS) and washout rate (WR) were determined from 123I-meta-iodobenzylguanidine (MIBG) images, and plasma brain natriuretic peptide (BNP) concentrations were measured before and 6 months after treatment. The left ventricular end-diastolic volume (LVEDV), left ventricular end-systolic volume (LVESV) and LVEF were also determined by echocardiography. After treatment, in patients receiving perindopril, TDS decreased from 39+/-10 to 34+/-9 (P < 0.01), H/M ratios increased from 1.62+/-0.27 to 1.76+/-0.29 (P < 0.01), WR decreased from 50+/-14% to 42+/-14% (P < 0.05) and plasma BNP concentrations decreased from 226+/-155 to 141+/-90 pg/ml (P < 0.0005). In addition, the LVEDV decreased from 180+/-30 to 161+/-30 ml (P < 0.05) and the LVESV decreased from 122+/-35 to 105+/-36 ml (P < 0.05). Although the LVEF tended to increase, the change was not statistically significant (from 33+/-8% to 36+/-12%; P = NS). On the other hand, there were no significant changes in these parameters in patients receiving enalapril. Plasma BNP concentrations, 123I-MIBG scintigraphic and echocardiographic parameters improved after 6 months of perindopril treatment. These findings indicate that perindopril treatment can ameliorate the cardiac sympathetic nerve activity and the left ventricular performance in patients with CHF.

Non-invasive assessment of coronary flow reserve in idiopathic dilated cardiomyopathy: hemodynamic correlations

Impaired vasodilator myocardial blood flow response has been observed in dilated cardiomyopathy (DCMP). However, the mechanisms responsible for this blunted response are not clear. In the present study, we investigated whether the blunted vasodilator flow response is related to indices of left ventricular performance in patients with idiopathic dilated cardiomyopathy. Eighteen DCMP patients and 12 healthy subjects (C) underwent transoesophageal echocardiography within 48 h from cardiac catheterization. Coronary flow velocity reserve (CFR) was measured in the proximal LAD as the ratio of the peak diastolic coronary flow velocity (Vd-M) after intravenous administration of adenosine to peak baseline diastolic flow velocity (Vd-R). Left ventricular (LV) mass index was positively correlated with baseline coronary diastolic velocity (r=0.415; p=0.043) and inversely correlated with coronary flow reserve (r=-0.570; p=0.003). The baseline coronary diastolic velocity was higher in DCMP vs C (56+/-13 cm/s vs 35+/-12 cm/s; p=0.04). In DCMP pts Vd-R positively correlated with end-diastolic wall stress (r=0.654; p=0.01). Vd increased in both C (96+/-32 cm/s; p<0.05 vs baseline) and DCMP patients (108+/-20 cm/s; p<0.01 vs baseline). The CFR was lower in DCMP patients vs C (1.93+/-0.78 vs 2.99+/-1.01; p=0.009). In DCMP pts CFR was negatively correlated with right atrial pressure (r=-0.595; p=0.015), LVEDP (r=-0.576; p=0.015), pulmonary capillary wedge pressure (PCWP: r=-0.772; p<0.001) and positively with ejection fraction (EF: r=0.683; p=0.003). Pts with DCMP have lower CFR compared to controls. This blunted CFR is due to higher baseline coronary flow and reflects higher wall stress. The close relation between CFR and EF, PCWP and LVEDP suggests that not only a higher baseline Vd but also compressive forces due to left ventricular dysfunction might be responsible for the observed blunted adenosine-mediated coronary vasodilation.

Left ventricular performance of pulmonary atresia with intact ventricular septum after right heart bypass surgery

The left ventricular performance in patients with pulmonary atresia with intact ventricular septum who were Fontan candidates before and after the bidirectional Glenn procedure and a staged total cavopulmonary connection was compared with that in patients with tricuspid atresia. Contractility (end-systolic elastance), afterload (effective arterial elastance), and ventricular efficiency (ventriculoarterial coupling, arterial elastance/end-systolic elastance ratio), and the ratio of stroke work and pressure-volume area were approximated on the basis of cardiac catheterization data before the bidirectional Glenn procedure, before and after staged total cavopulmonary connection, and approximately 1 year after the completion of total cavopulmonary connection in 20 patients with pulmonary atresia with intact ventricular septum and 21 patients with tricuspid atresia. The end-systolic elastance of the pulmonary atresia with intact ventricular septum group was significantly inferior to that of the tricuspid atresia group after bidirectional Glenn procedure and total cavopulmonary connection (1 year after total cavopulmonary connection 1.85 +/- 0.51 mm Hg . m 2 . mL -1 vs 2.84 +/- 0.96 mm Hg . m 2 . mL -1 , P < .01). The arterial elastance was not different between groups throughout the assessment period and tended to increase in a stepwise fashion after bidirectional Glenn procedure and total cavopulmonary connection. The arterial elastance/end-systolic elastance ratio and ratio of stroke work and pressure-volume area of the pulmonary atresia with intact ventricular septum group tended to worsen, whereas those of the tricuspid atresia group tended to improve. The difference reached statistical significance 1 year after total cavopulmonary connection (1.15 +/- 0.35 vs 0.82 +/- 0.23 and 64.2% +/- 6.7% vs 71.3% +/- 5.7%, respectively, P < .05 and P < .05, respectively). The contractility and ventricular efficiency of patients with pulmonary atresia with intact ventricular septum are inferior to those of patients with tricuspid atresia after bidirectional Glenn procedure and total cavopulmonary connection. A high-pressure residual right ventricle may impair the left ventricular performance of patients with pulmonary atresia with intact ventricular septum after bidirectional Glenn procedure and total cavopulmonary connection.

Oxipurinol: alloxanthine, Oxyprim, oxypurinol.

Oxipurinol: alloxanthine, Oxyprim, oxypurinol.

Left Ventricular Performance in Patients With Severe Acute Respiratory Syndrome

Severe acute respiratory syndrome (SARS) is characterized by an overaggressive immune response. Myocardial performance may be impaired in cytokine-mediated immune reactions. Forty-six patients with established clinical diagnosis of SARS were studied prospectively. Transthoracic echocardiographic examinations were done at the acute stage of infection and 30 days later. Among them, 14 patients required mechanical ventilation. The clinical course, laboratory data, SARS-CoV antibody titers, and results of reverse transcriptase-polymerase chain reaction were studied. Significantly higher left ventricular index of myocardial performance (IMP) (0.42+/-0.13 versus 0.33+/-0.09, P<0.001), longer isovolumic relaxation time (102.9+/-15.7 versus 81.6+/-14.7 ms, P<0.001), lower flow propagation velocity (69.6+/-15.7 versus 83.8+/-19.7 cm/s, P=0.011), and Doppler-derived cardiac output (4.69+/-1.01 versus 5.49+/-1.04 L/min, P<0.001) were observed during acute infection when compared with those at 30 days. No significant valvular disease or pulmonary hypertension was found. At baseline, a lower mean left ventricular ejection fraction (LVEF) (65.3+/-12.8% versus 71.4+/-5.7%, P=0.03) and a higher mean IMP (0.51+/-0.11 versus 0.40+/-0.12, P=0.017) were found in patients who required mechanical ventilation. A decrease in LVEF correlated moderately with an elevated lactate dehydrogenase level (r=-0.605, P<0.001), whereas a higher IMP correlated weakly with an increase in creatine kinase level (r=0.38, P=0.016). Histological examination of the heart in the patient with the lowest EF (30.2%) revealed no interstitial lymphocytic infiltrate or myocyte necrosis. Subclinical diastolic impairment without systolic involvement was observed in patients with SARS. This impairment may be reversible on clinical recovery.

P2770 The effect of two different pacing modes on global left-ventricular performance in patients with atrioventricular block: a tissue Doppler echocardiography study

P2770 The effect of two different pacing modes on global left-ventricular performance in patients with atrioventricular block: a tissue Doppler echocardiography study