Isolation-stress-induced facilitation of passive avoidance memory in the day-old chick

Left ventricular (LV) midwall shortening (MWS) is subnormal in relation to LV circumferential end-systolic stress (ESS) (ESS-corrected MWS) in many hypertensive patients with normal LV chamber function and predicts subsequent morbidity and mortality. However, little is known of the relations of LV midwall function to demographic and metabolic variables or to arterial geometry. Asymptomatic, unmedicated normotensive (n=366) or hypertensive (n=282) adults were assessed with echocardiography and carotid ultrasound. In normal adults, lower LV MWS and ESS-corrected MWS, an index of LV contractility, were related independently to high total peripheral resistance, high heart rate, and male gender (all P<.00001), lower serum HDL cholesterol (P=.001) and diastolic pressure (P=.003), and for ESS-corrected MWS only, arterial relative wall thickness (RWT, P=.03). Among hypertensive patients, lower values for both midwall function indices were associated independently with higher peripheral resistance (P<.00001), heart rate (P<.00005), body mass index (P<.01), and arterial RWT (P=.04), as well as male gender (P<.0002). In the entire population, lower LV MWS was independently related to higher peripheral resistance, heart rate (both P<.00001), body mass index (P=.0006) and arterial RWT (P=.009); male gender (P<.00001); and lower age (P=.004), diastolic pressure (P=.042), and systolic carotid artery expansion (P=.032). Lower ESS-corrected MWS in the entire population was independently associated with higher peripheral resistance and heart rate (both P<.00001), body mass index (P=.0006), arterial RWT (P=.004); male gender; and lower diastolic pressure (both P<.00001), age (P<.00005), arterial expansion in systole (P=.006), and serum HDL cholesterol levels (P=.04). Among a subset (n=60), ESS-corrected MWS was positively related to apolipoprotein A1 (P=.004) and negatively to hemoglobin A1c (P<.01). Thus, higher LV midwall function is associated with female gender and more favorable profiles of hemodynamics, metabolic pattern, and arterial structure and function.     

Relationships between left ventricular mass, left ventricular work and coronary artery size in aortic regurgitation--possible mechanism of myocardial ischemia

To investigate the relationships between coronary artery size, left ventricular (LV) mass, and LV stroke work in aortic regurgitation (AR), these values were measured in 19 patients with severe AR. Twenty normal subjects and 15 patients with mitral regurgitation (MR) were used as control groups. The coronary area index, i.e., the coronary cross-sectional area divided by body surface area (BSA), was larger in the AR group than in the control groups in all measured sites except for the peripheral left anterior descending coronary artery (LAD) and right coronary artery (RCA). However, the coronary area index divided by the LV mass was significantly smaller in AR and MR patients than in normal subjects. Furthermore, the coronary area index divided by LV stroke work was smaller in AR patients than in MR patients and normal subjects. These results suggest that the coronary blood flow associated with the increased LV mass and stroke work caused by regurgitation was insufficient in patients with severe AR, especially in the area of the LAD. Therefore, the occurrence of myocardial ischemia in patients with severe AR may involve inadequate enlargement of the coronary artery which perfuses the LV, in addition to factors such as decreased coronary perfusion pressure, increased coronary artery resistance and decreased coronary flow reserve.     

Evaluation of left ventricular early diastolic performance by color tissue Doppler imaging of the mitral annulus

A noninvasive assessment of left ventricular (LV) diastolic performance by tissue Doppler imaging was performed in 56 patients (8 patients with atypical chest pain, 42 with coronary artery disease with a previous myocardial infarction, and 6 without a previous myocardial infarction) who underwent cardiac catheterization. Mitral annular velocity (MAV) during early ventricular diastole was obtained by M-mode color tissue Doppler imaging at the posterior corner of the mitral annulus. In each patient, the negative peak of the first derivative of LV pressure decay (peak -dP/dt) and a time constant of LV relaxation (tau) were calculated from the LV pressure waves obtained by a catheter-tip micromanometer. LV end-systolic volume index was measured from contrast left ventriculography. MAV during early diastole was significantly correlated with tau (r = -0.73, p <0.001), peak -dP/dt (r = 0.58, p <0.001), and LV end-systolic volume index (r = -0.63, p <0.001). On multivariate regression analysis with MAV during early diastole, tau and LV end-systolic volume index were selected as prime determinants (r = 0.80, p <0.001). These findings suggest that MAV during early diastole has a direct relation to LV elastic recoil as well as to LV relaxation. MAV during early diastole gives important information regarding LV behavior in late systole to early diastole where LV early diastolic performance is determined.     

Coronary back flow pressure is elevated in association with increased left ventricular end-diastolic pressure in humans

To clarify the effect of left ventricular (LV) diastolic pressure on the coronary pressure-flow relation in humans, the instantaneous diastolic coronary pressure-Doppler flow velocity relation was analyzed at rest and during papaverine-induced maximal vasodilation in 15 patients with angiographically normal coronary arteries. The values for slope (alpha PF) and zero-flow pressure intercept (Pzf index) of the instantaneous diastolic coronary pressure-flow velocity relation were obtained by a linear regression analysis. Although alpha PF did not correlate with LV end-diastolic pressure (EDP), the Pzf index correlated positively with LVEDP both at rest and during maximal vasodilation (r = 0.64, P < 0.05 and r = 0.58, P < 0.05, respectively). Thus, the back pressure to coronary inflow, as indicated by the Pzf index, may be elevated in patients with increased LVEDP, resulting in the rightward shift of the maximally dilated coronary pressure-flow relation and decreased maximal coronary flow and reserve at any given perfusion pressure.     

Presurgical profile preferences of patients and clinicians

BACKGROUND: Aortic regurgitation results from a pressure gradient across the aortic valve during left ventricular (LV) isovolumic relaxation, LV filling, and isovolumic contraction periods. Assuming the applicability of the simplified Bernoulli equation to this pressure-flow relation and constancy of aortic pressure during LV isovolumic relaxation and contraction periods, one can theoretically obtain estimates of the rates of LV isovolumic pressure fall and rise (deltaP/delta t) from the aortic regurgitation (AR) velocity signal. METHODS AND RESULTS: Mitral regurgitation (MR) and AR signals were recorded by using the continuous wave Doppler technique in 26 patients with combined mitral and aortic regurgitant lesions. The LV negative deltaP/delta t was obtained by dividing the time taken for the AR velocity to rise from 1 m/sec to 2.5 m/sec into 21 mm Hg, which is the estimated LV pressure drop between these points. In a similar fashion, the LV positive deltaP/delta t was obtained between 2.5 m/sec and 1 m/sec of the fast decelerating portion of the AR signal. The LV negative deltaP/delta t by the AR method ranged from 420 to 3500 mm Hg/sec and correlated well with that obtained by the MR method obtained in a blinded fashion (r = 0.95, p < 0.0001). The mean (SD) difference between the two methods was 30 (129) mm Hg/sec. Similarly, the LV positive deltaP/delta t by the AR method (range 420 to 2625 mm Hg/sec) correlated closely with that obtained by the MR method (r = 0.93, p < 0.0001), with the mean (SD) difference between the two methods being 38 (138) mm Hg/sec. CONCLUSIONS: Preliminary data presented in this study indicate the feasibility of obtaining a reliable estimate of LV positive and negative deltaP/delta t from the AR velocity profile. Thus the examination of the AR signal may give valuable insights into both LV systolic and diastolic functions.     

Radionuclide (MUGA) studies of left ventricular functional abnormalities in asymptomatic patients with sickle cell anemia

Radionuclide ventriculography was performed on 10 normal subjects and 39 patients with sickle cell anemia (10 homozygous and 29 heterozygous sicklers) at rest and after exercise. Their left ventricular (LV) function was assessed in both these situations. The results were then compared within the subgroups. The reduction in ejection fraction (EF) response (47.5 +/- 7 at rest and 46.4 +/- 8 at exercise in homozygous patients, and 52.4 +/- 8 at rest and 54.3 +/- 8 at exercise in heterozygous patients) was significant in both the homozygous and the heterozygous groups but more so in the former group. The diastolic filling was also significantly impaired in the homozygous group (PER 2.64 +/- 0.74, PFR 2.13 +/- 0.42 and PFR/HR 0.014 +/- 0.001). The study statistically demonstrates, that LV filling patterns are altered in the sickle cell patients, even in the absence of clinical symptoms relating to LV dysfunction. This fact may prove to be a marker of sickle cell heart disease. Frequent and significant sickling is probably the cause of more pronounced LV functional abnormalities in homozygous sicklers.     

Efficacy of coronary artery bypass grafting in patients with a dilated left ventricle due to myocardial infarction

This study was designed to clarify the efficacy of coronary artery bypass grafting (CABG) on left ventricular (LV) function in 16 patients with a dilated LV due to myocardial infarction (LV end-systolic volume index: LVESVI >60 ml/m2). All had attained complete revascularization. To estimate the LV wall motion quantitatively using echocardiography, a wall motion score (WMS) was used (LV was divided into 17 segments with a four-point scale: akinesis=3, severe hypokinesis=2, hypokinesis=1, normal=0 and then summed). Exercise stress tests were performed after surgery, revealing that anginal symptoms had vanished in all the patients. In 5 patients with a preoperative end-systolic volume index (ESVI) >100 ml/m2, the ejection fraction (EF) did not change, and both were under 30% (before to after: 26+/-4 to 26+/-4%). Neither the ESVI (148+/-50 to 133+/-39 ml/m2) nor the end-diastolic volume index (end-diastolic volume index (EDVI): 198+/-62 to 180+/-37 ml/m2) changed; the WMS did not change (33+/-2 to 33+/-3). During exercise, in spite of the increase in heart rate (HR) (at rest, 81+/-20; HR during exercise, 111+/-21 beats/min, p<0.005) and LV end-diastolic pressure (EDP) (22+/-9; 35+/-13 mmHg, p<0.02), both cardiac index (CI) (2.4+/-0.3; 2.6+/-0.4 L/min x m2) and minute work (MW: 4.0+/-1.1; 4.1+/-0.4 kg x M/min) did not increase. In 11 patients with a preoperative ESVI <100 ml/m2, EF was extremely increased in 5 patients (more than 10%, 35+/-4 to 60+/-6%, p<0.005=improved subgroup) in whom the EDVI (130+/-16 to 120+/-13 ml/m2) did not change whereas the ESVI (82+/-14 to 48+/-7 ml/m2) was reduced. However, in the 6 remaining patients (ie nonimproved subgroup), neither ESVI (78+/-8 to 74+/-12 ml/m2), EDVI (115+/-10 to 115+/-20 ml/m2) nor EF (31+/-7 to 35+/-3%) changed. During exercise, HR (at rest, 88+/-13; during exercise, 108+/-11 beats/min, p<0.005), LVEDP (20+/-6; 29+/-7 mmHg, p<0.01), CI (2.5+/-0.6; 3.3+/-0.5 L/min x m2, p<0.05), MW (4.6+/-1.0; 6.5+/-1.5 kg x M/min, p<0.05) increased. The WMS in the nonimproved subgroup did not change (29+/-6 to 27+/-2), but in the improved subgroup it reduced after surgery (27+/-3 to 19+/-4, p<0.01). These data suggested that CABG in patients with a dilated LV was effective against anginal symptoms, but was restricted to left ventricular function. It may be possible to estimate postoperative LV function, including exercise tolerance, from the preoperative LVESVI.     

Application of endoscopic sinus surgery to primary atrophic rhinitis? A clinical trial

The aetiology of primary atrophic rhinitis (AR) is still unclear. Based on the sinus infection theories, endoscopic sinus surgery (ESS) was applied to treat AR. ESS was performed on 14 patients following Stammberger's techniques along with middle turbinectomy. Patients were evaluated using clinical symptoms, radiological sinus images, saccharine time tests, bacterial cultures and mucosal ultrastructures, before and 2 years after ESS. Three patients had good recoveries, 6 had partial recoveries and another 5 had persistent disease. Good recovery patients showed clear nasal cavities and mucociliary transport system normalisation. Patients possess in meagre infectious signs or crusting extending to their nasopharynx had poor outcomes. Patients with evidence of obvious infections (cloudy sinus images, mucopus presence in the sinuses and positive culture for Klebsiella ozaenae) had good recoveries following ESS. Candidate selection is critical for the success of ESS treatment in AR. Although further clinical trials are required to prove this strategy.     

A novel monoclonal antibody permitting recognition of NKT cells in various mouse strains

OBJECTIVES: The purpose of this study was to determine whether restrictive left ventricular (LV) filling patterns are associated with diastolic ventricular interaction in patients with chronic heart failure. BACKGROUND: We recently demonstrated a diastolic ventricular interaction in approximately 50% of a series of patients with chronic heart failure, as evidenced by paradoxic increases in LV end-diastolic volume despite reductions in right ventricular end-diastolic volume during volume unloading achieved by lower body negative pressure (LBNP). We reasoned that such an interaction would impede LV filling in mid and late diastole, but would be minimal in early diastole, resulting in a restrictive LV filling pattern. METHODS: Transmitral flow was assessed using pulsed wave Doppler echocardiography in 30 patients with chronic heart failure and an LV ejection fraction < or = 35%. Peak early (E) and atrial (A) filling velocities and E wave deceleration time were measured. Left ventricular end-diastolic volume was measured using radionuclide ventriculography before and during -30-mm Hg LBNP. RESULTS: Nine of the 11 patients with and 2 of the 16 patients without restrictive LV filling patterns (E/A > 2 or E/A 1 to 2 and E wave deceleration time < or = 140 ms) increased LV end-diastolic volume during LBNP (p = 0.001). The change in LV end-diastolic volume during LBNP was correlated with the baseline A wave velocity (r = -0.52, p = 0.005) and E/A ratio (r = 0.50, p = 0.01). CONCLUSIONS: Restrictive LV filling patterns are associated with diastolic ventricular interaction in patients with chronic heart failure. Volume unloading in the setting of diastolic ventricular interaction allows for increased LV filling. Identifying patients with chronic heart failure and restrictive filling patterns may therefore indicate a group likely to benefit from additional vasodilator therapy.     

Changes in leg vein filling and emptying characteristics and leg volumes during long-term head-down bed rest

Leg venous hemodynamics [venous distensibility index (VDI), arterial flow index (AFI), half-emptying time (T1/2)], and leg volumes (LV) were assessed by mercury strain-gauge plethysmography with venous occlusion and volometry, respectively, in seven men before, during, and after 42 days of 6 degrees head-down bed rest. Results showed a high increase in VDI up to day 26 of bed rest (+50% vs. control at day 26, P < 0.05), which tended to subside thereafter (+20% increase vs. control value at day 41, P < 0.05). VDI changes were associated with parallel changes in T1/2 (+54% vs. control at day 26 of bed rest, P < 0.05, and +25% vs. control at day 41, P < 0.05) and with a decrease in AFI (-49% at day 41 vs. P < 0.05). LV continuously decreased throughout bed rest (-13% vs. control at day 41, P < 0.05) but was correlated with VDI only during the first month of bed rest. These results show that during long-term 6 degrees head-down bed rest alterations of leg venous compliance are associated with impairment of venous emptying capacities and arterial flow. Changes in skeletal muscle mass and fluid shifts may account for venous changes during the first month of bed rest but, subsequently, other physiological factors, to be determined, may also be involved in leg venous hemodynamic alterations.     

Scientific challenges in environmental carcinogenesis

Myocardial uptake of iodine-123 meta-iodobenzylguanidine (123I-MIBG) was measured using scintigrams at rest in 12 patients with isolated, nonischemic mitral regurgitation (MR; regurgitant fraction 64% +/- 7%) and was related to the left ventricular (LV) function assessed by cardiac catheterization. Iodine-123 meta-iodobenzylguanidine activity in the upper mediastinum, liver, and lung was comparable between MR and control (n = 8) patients. The heart-to-mediastinum 123I-MIBG activity ratio 4 hours after injection was significantly (p < 0.01) decreased in MR (2.0 +/- 0.1, mean +/- SE) compared with control (2.7 +/- 0.1) with the increased clearance of MIBG. In addition, MR patients had significantly greater heterogeneity in the 123I-MIBG distribution within the myocardial images (26.1% +/- 2.1% intraimage variability for MR versus 15.6% +/- 0.8% for control, p < 0.01). Myocardial 123I-MIBG activity correlated positively with cardiac index and negatively with pulmonary capillary wedge pressure and LV volume indexes. Thus, 123I-MIBG scintigrams can be a noninvasive method for assessing the contractile dysfunction in MR.     

Ejection fraction by radionuclide ventriculography and contrast left ventriculogram. A tale of two techniques. SAVE Investigators. Survival and Ventricular Enlargement

OBJECTIVES: We assessed the abilities of two methods to measure ejection fraction (EF)-radionuclide ventriculography (RVG) and contrast left ventriculography (Cath-EFa) to predict cardiovascular events. BACKGROUND: Both RVG and Cath-EFa are commonly used methods to measure left ventricular performance and assess prognosis. Their comparative abilities to predict clinical events have not been reported. METHODS: Both RVG EF and Cath-EFa were measured within 16 days of myocardial infarction (MI) in 688 patients. The results were divided into terciles. Prognosis by terciles was assessed for each technique. A multivariate analysis was performed to determine which EF measurement was a better predictor of prognosis. RESULTS: Average RVG-EF was 32%+/-7, while Cath-EFa was 42%+/-10. Both RVG and Cath-EFa were poorly correlated (R=0.42). Event rate declined across terciles with increasing EF for both techniques (events in lowest to highest tercile of Cath-EFa 40.7%, 25.9%, 11.6%, p < 0.001; and RVG-EF 39.9%, 26.1%, 15.6%, p < 0.001). There was concordance of terciles in 303 of 688 patients (44%). When patients in the highest RVG terciles were in the highest Cath-EFa tercile, the event rate was 7%. However, when patients in the highest RVG terciles were in the lowest Cath-EFa tercile, the event rate was 19%. Both Cath-EFa (p < 0.001) and RVG-EF (p < 0.001) were independent predictors of cardiovascular events. CONCLUSIONS: Ejection fraction measured by RVG or during catheterization is a valuable tool in the risk stratification of postinfarct patients. When disagreement is present between clinical impression and measurement by either method, the use of an alternative measurement is warranted and complementary.     

Increased myocardial echo density in left ventricular pressure and volume overload in human aortic valvular disease: an ultrasonic tissue characterization study

Quantitatively assessed ultrasonic backscatter is an index of ultrasonic tissue characterization directly related to morphometrically evaluated collagen in human beings. Our objective was to assess myocardial reflectivity pattern of patients with severe left ventricular hypertrophy caused by either aortic stenosis (AS) or aortic regurgitation (AR). Ten patients with AS, 10 patients with AR, and 10 closely age- and gender-matched healthy controls were studied by two-dimensional Doppler echocardiography. By using an echocardiographic prototype, we performed a radiofrequency analysis to obtain quantitative operator-independent measurements of the integrated backscatter signal of the ventricular septum and the posterior wall (integrated backscatter index: IBI, expressed in percentage). All patients with stenosis or aortic insufficiency showed a normal regional and global resting systolic function (fractional shortening: AS = 36.0 +/- 6.6 versus AR = 40.3 +/- 6.2 versus control = 40.2 +/- 8.7; p = not significant [NS]) Left ventricular mass index (Devereux's formula) was markedly increased in patients with stenosis or aortic insufficiency (AS = 199.3 +/- 18 versus AR = 208.8 +/- 60 versus control = 97.3 +/- 11 g/m2; p < 0.0001). Myocardial echo density was increased in patients with stenosis or aortic insufficiency in comparison with controls, both in the septum (IBI%: AR = 40.7 +/- 7.9 versus AS = 33.4 +/- 4.2 versus control = 23.0 +/- 6.2; p < 0.0001) and in the posterior wall (IBI%: AR = 27.1 +/- 4.3 versus AS = 23.0 +/- 2.6 versus control = 15.0 +/- 4.2; p < 0.0001). No significant correlations were found between septal and posterior wall IBI and their thickness. Abnormally increased myocardial echo density--possibly related to disproportionate collagen deposition--can be detected in patients with pressure or volume overload caused by aortic valve disease and without overt systolic dysfunction.     

Enhancement of opsin activity by all-trans-retinal

This study examines the hemodynamic performance of small size St. Jude BioImplant aortic prostheses using dobutamine echocardiography. Eleven patients (3 women, mean age 75 years) who had undergone aortic valve replacement with a size 21-mm St. Jude BioImplant aortic prostheses at 10.8 +/- 5.1 months (SD) previously were studied. Dobutamine infusion was started at a rate of 5 microg/kg/min and increased to 10 microg/kg/min, and subsequently to 20 microg/kg/min at 15-minute intervals. Pulsed and continuous-wave Doppler studies were performed at rest and at the end of each stage. Effective orifice area, mean gradient, and the performance index across each prosthesis were calculated and cardiac output was determined by Doppler measurement of flow in the left ventricular outflow tract. Stress dobutamine increased heart rate and cardiac output by 51% and 56%, respectively (both p <0.0001), and the mean transvalvular gradient increased from 30.1 +/- 7.5 mm Hg at rest to 49.3 +/- 11.5 mm Hg at maximum stress (p <0.0005). The performance index increased progressively from 0.29 +/- 0.05 at rest to 0.40 +/- 0.10 at maximum stress (p <0.0005). Regression modeling analyses demonstrated that the maximum stress gradient was independent of all variables except the resting gradient (p = 0.03). Body surface area had no effect on the changes in cardiac output, effective orifice area, or transprosthetic gradient at maximum stress. Thus, these data demonstrate that the size 21-mm St. Jude BioImplant prosthesis exhibits suboptimal hemodynamic performance with transvalvular gradients consistent with mild to moderate aortic stenosis, both at rest and under stress conditions.     

High-dose trimetrexate and minimal-dose leucovorin: a case for selective protection?

Our objective was to find the minimum dose of leucovorin (LV; 5-formyltetrahydrofolate) needed to potentially provide selective protection of normal tissue in patients with tumors resistant to methotrexate (MTX) by virtue of transport during prolonged therapy with high-dose trimetrexate (TMTX). Based upon the known daily requirement for folate, that tumors are often resistant to methotrexate via a transport-based mechanism, and that large doses of trimetrexate can be given with large doses of leucovorin for the treatment of patients with Pneumocystis carinii, a protocol was designed to find the minimum LV dose required to allow the administration of large doses of TMTX. Patients were treated in 28-day cycles consisting of 14 consecutive days of oral TMTX (45 mg/m2 every 12 h), followed by 14 days of rest. The dose of concurrent LV was started at 5 mg/m2 twice daily. Cohorts of patients received successive half doses of LV so long as three consecutive patients had less than or equal to grade 3 toxicity. Ten patients received 29 courses of therapy. The most common toxicities encountered were thrombocytopenia (38%), mucositis (14%), and neutropenia (10%). At a LV dose of 2.5 mg/m2, toxicities were consistently limited to less than or equal to grade 3 and only one episode of grade 4 hematological toxicity. Although there was marked interpatient variability, the minimally effective LV dose for selective protection seems to be 2.5 mg/m2. If tumors are resistant to methotrexate because of decreased transport of drug (and also folate), then the same pharmacological principle used to develop TMTX/LV for the treatment of P. carinii may be applied to treatment of some patients with cancer.     

Left ventricular geometry and severe left ventricular hypertrophy in children and adolescents with essential hypertension

BACKGROUND: Left ventricular (LV) hypertrophy has been established as an independent risk factor for cardiovascular disease in adults. Recent research has refined this relationship by determining a cutpoint of 51 g/m(2.7) for LV mass index indicative of increased risk and defining LV geometric patterns that are associated with increased risk. The purpose of this study was to evaluate severe LV hypertrophy and LV geometry in children and adolescents with essential hypertension. METHODS AND RESULTS: A cross-sectional study of young patients (n=130) with persistent blood pressure elevation above the 90th percentile was conducted. Nineteen patients (14%) had LV mass greater than the 99th percentile; 11 of these were also above the adult cutpoint of 51 g/m(2.7). Males, subjects with greater body mass index, and those who had lower heart rate at maximum exercise were at significantly (P<.05) higher risk of severe LV hypertrophy. In addition, 22 patients (17%) had concentric LV hypertrophy, a geometric pattern that is associated with increased risk of cardiovascular disease in adults. Seven patients had LV mass index above the cutpoint and concentric hypertrophy. No consistent significant determinants of LV geometry were identified in these children and adolescents with hypertension. CONCLUSIONS: Severe LV hypertrophy and abnormal LV geometry are relatively prevalent in young patients with essential hypertension. These findings suggest that these patients may be at risk for future cardiovascular disease and underscore the importance of recognition and treatment of blood pressure elevation in children and adolescents. Weight loss is an important component of therapy in young patients with essential hypertension who are overweight.     

Effects of partial left ventriculectomy on left ventricular performance in patients with nonischemic dilated cardiomyopathy

OBJECTIVES: This study sought to assess the effects of partial left ventriculectomy (PLV) on left ventricular (LV) performance in a series of consecutive patients with nonischemic dilated cardiomyopathy. BACKGROUND: Reduction of LV systolic function in patients with heart failure is associated with an increase of LV volume and alteration of its shape. Recently, PLV, a novel surgical procedure, was proposed as a treatment option to alter this process in patients with dilated cardiomyopathy. METHODS: We studied 19 patients with severely symptomatic nonischemic dilated cardiomyopathy, before and 13+/-3 days after surgery, and 12 controls. Single-plane left ventriculography with simultaneous measurements of femoral artery pressure was performed during right heart pacing. RESULTS: The LV end-diastolic and end-systolic volume indexes decreased after PLV (from 169 to 102 ml/m2, and from 127 to 60 ml/m2, respectively, p < 0.0001 for both). Despite a decrease in LV mass index (from 162 to 137 g/m2, p < 0.0001), there was a significant decrease in LV circumferential end-systolic and end-diastolic stresses (from 277 to 159 g/cm2, p < 0.0001 and from 79 to 39 g/cm2, p = 0.0014, respectively). Ejection fraction improved (from 24% to 41%, p < 0.0001); the stroke work index remained unchanged. CONCLUSIONS: The PLV improves LV performance by a dramatic reduction of ventricular end-systolic and end-diastolic stresses. Further studies are needed to assess whether this effect is sustained during long-term follow-up and to define the role of PLV in the treatment of patients with dilated cardiomyopathy.     

Hemodynamic performance of cryopreserved aortic homograft valves during midterm follow-up

OBJECTIVES: The aim of this prospective study of adult patients operated with a cryopreserved aortic homograft was to use serial echocardiographic data to evaluate the postoperative hemodynamic performance of these valves. BACKGROUND: Only limited data on hemodynamic performance of aortic homografts at rest and during exercise are available. Controversy also exists regarding incidence and progression of aortic regurgitation (AR). METHODS: Fifty-nine patients aged 39-86 years who received an aortic homograft (median size 21 mm) implanted with subcoronary technique were studied with serial Doppler-echocardiography (D-E). In 31 of these patients, D-E also was performed during supine exercise. RESULTS: Overall survival was 100% during a median follow-up of 28 months (range 4-54). During follow-up AR grade II or more was detected in 25% of the patients with an increasing time-related risk of developing AR. Maximum and mean pressure differences at 7 months follow-up calculated with the short form of the Bernoulli equation were 11.4 (4.6) and 5.5 (2.1) mm Hg, respectively. During supine exercise that increased cardiac output 72%, maximum pressure difference increased from 11.9 (5.2) to 18.5 (9.5) mm Hg. CONCLUSIONS: The aortic homograft valve shows low pressure differences at rest and during exercise, but AR grade I or II is often seen during follow-up. As AR progresses with time we stress the importance of echocardiographic follow-up of patients with aortic homografts.     

Autograft failure after the Ross operation in a rheumatic population: pre- and postoperative echocardiographic observations

BACKGROUND AND AIMS OF THE STUDY: Between January 1990 and July 1995, 108 patients underwent the Ross operation at our hospital. Most patients (90%) had severe aortic regurgitation (AR) in the setting of rheumatic heart disease. Although there have been no perioperative or late cardiac deaths, 12 patients (11%) developed severe AR requiring reoperation. MATERIAL AND METHODS: We performed an extensive and mostly retrospective analysis of echocardiographic data on all patients. Preoperative data were analyzed for age, sex, body surface area (BSA), size and comparison of the left and right ventricular outflow tracts (LVOT, RVOT), left ventricular (LV) size and function, and the presence of pulmonary regurgitation (PR) and concomitant mitral regurgitation (MR). Follow up data were analyzed for the presence, time of onset, evolution and severity of AR, characteristics of the AR jet, anatomic and functional aspects of the aortic root and valve, and evolution of LVOT diameter and LV size and function. RESULTS: Patients with autograft failure were younger with smaller BSA, larger indexed size of LVOT, RVOT and LV, and significantly more had concomitant severe MR. Postoperatively they had larger and increasing LVOT size. Trivial or mild AR was common and seen in almost all patients, as was a minimal degree of preoperative PR. Severe AR developed mostly after the first year of follow up, and reoperation was performed within three years in 11/12 patients. In nine patients cusp dilatation and prolapse (most frequently of the posterior cusp) was the cause of the AR, and rheumatic activity in three. Reoperation was not associated with mortality. CONCLUSION: In our population autograft failure seems to be related to age, BSA and (indexed) LVOT, RVOT and LV size, but only the presence of significant concomitant mitral regurgitation before surgery was identified as a predictor for reoperation. Prolapse of one or more cusps were the cause of the AR in most patients. The graft is sensitive for recurrent rheumatic activity.