ABSTRACT
ABSTRACT Agrobacterium vitis is the causal agent of crown gall disease in grapevine, which can be severe in many regions worldwide. Vitis vinifera cultivars are highly susceptible to freeze injury, providing the wounds necessary for infection by A. vitis. Wound position in relation to the uppermost bud of cuttings was determined to be important in tumor development. Inoculated wounds below buds developed tumors, whereas wounds opposite the bud did not, implying that indole-3-aectic acid flow contributes to tumor formation. If auxin was applied to wounds prior to inoculation with a tumorigenic A. vitis strain, all sites of inoculation developed tumors, accompanied by an increased amount of callus in the cambium. Wounds inoculated with an A. vitis biological control strain F2/5 prior to application of the pathogen did not develop galls. A closer examination of these wounds determined that callus cells formed in the cambium during wound healing are susceptible to transformation by the pathogen. Although the mechanism by which F2/5 prevents transformation is unknown, our observations suggest that F2/5 inhibits normal wound healing by inducing necrosis in the cambium.
ABSTRACT
Crown gall was detected in several vineyards in the Central Anatolia region of Turkey. Vineyards were planted to cultivars of grape that originated in Turkey and that were not grafted. The predominant species isolated from galls consisted of tumorigenic strains of Agrobacterium vitis. They were identified based on reactions to standard biochemical and physiological tests, by polymerase chain reaction amplification of specific Ti plasmid and chromosomal sequences, and by reaction to a species-specific monoclonal antibody. All strains utilized octopine, suggesting that they may carry similar types of Ti plasmids. Some of the strains exhibited a differential host range compared with others and were less virulent based on the numbers of galls that they induced on grape. When grapevines were treated with nontumorigenic A. vitis strain F2/5 prior to inoculation with the Turkish A. vitis strains, crown gall was effectively controlled. The genetic diversity of strains was evaluated by comparing DNA fingerprints that were generated by restriction enzyme digestion of the intergenic spacer region that lies between 16S and 23S rRNA genes. They segregated into two main groups, one that is similar to previously identified A. vitis strains carrying octopine type Ti plasmids and one that was more similar to strains carrying nopaline and vitopine Ti plasmids. The strains of A. vitis from Turkey may represent ancestral forms of the pathogen that will provide insight into the evolution of the bacterium.
ABSTRACT
CONTEXT: Use of anorexigen therapy is associated with valvular abnormalities, although there is limited information on long-term changes in valvular regurgitation following discontinuation of these agents. OBJECTIVE: To evaluate changes in valvular regurgitation, valve morphology, and clinical parameters 1 year after an initial echocardiogram in patients previously treated with dexfenfluramine or phentermine/fenfluramine and in untreated controls. DESIGN AND SETTING: A reader-blinded, multicenter, echocardiographic and clinical 1-year follow-up study at 25 outpatient clinical sites. PATIENTS: A total of 1142 obese patients (1466 participated in the initial study) who had follow-up echocardiogram; all but 4 had a follow-up medical history and physical examination. Follow-up time from discontinuation of drug to follow-up echocardiogram for 371 dexfenfluramine patients was 17.5 months (range, 13-26 months) and for 340 phentermine/fenfluramine patients was 18.7 months (range, 13-26 months) after discontinuation of drug therapy. MAIN OUTCOME MEASURE: Change in grade of valvular regurgitation and valve morphology and mobility. RESULTS: Echocardiographic changes in aortic regurgitation were observed in 8 controls (7 [1.7%] had decreases; 1 [0.2%] had an increase); 29 dexfenfluramine patients (23 [6.4%] had decreases; 6 [1.7%] had increases; P<.001 vs controls); and 15 phentermine/fenfluramine patients (4.5% all decreases; P =.03 vs controls). No statistically significant differences were observed when treated patients were compared with controls for changes in medical history, physical findings, mitral regurgitation, aortic or mitral leaflet mobility or thickness, pulmonary artery systolic pressure, ejection fraction, valve surgery, or cardiovascular events. CONCLUSION: Progression of valvular abnormalities is unlikely in patients 1 year after an initial echocardiogram and 13 to 26 months after discontinuation of dexfenfluramine and phentermine/fenfluramine.
Subject(s)
Appetite Depressants/adverse effects , Central Nervous System Stimulants/adverse effects , Dexfenfluramine/adverse effects , Fenfluramine/adverse effects , Heart Valve Diseases/chemically induced , Heart Valve Diseases/diagnostic imaging , Phentermine/adverse effects , Serotonin Agents/adverse effects , Adult , Aged , Aortic Valve Insufficiency/chemically induced , Aortic Valve Insufficiency/diagnostic imaging , Echocardiography , Female , Follow-Up Studies , Humans , Logistic Models , Male , Middle Aged , Mitral Valve Insufficiency/chemically induced , Mitral Valve Insufficiency/diagnostic imaging , Obesity/drug therapyABSTRACT
Previous studies using pulsed Doppler echocardiography have demonstrated a pattern of abnormal left ventricular relaxation associated with increasing age. Specifically, aging is associated with decreased peak velocity of early diastolic mitral inflow, increased peak velocity of late diastolic inflow, increased isovolumic relaxation time, and early diastolic deceleration time. Abnormal relaxation can progress to significantly elevated left atrial pressure--characterized by increased early peak velocity and shortened isovolumic relaxation time and deceleration time--as part of the disease processes. Left ventricular diastolic dysfunction is highly prevalent, occurring in one half to two thirds of elderly patients with congestive heart failure, in association with normal systolic function. Left ventricular hypertrophy, which is commonly related to systemic arterial hypertension, and ischemic heart disease are the two major causes of abnormal left ventricular diastolic function in the elderly. Recently, newer echocardiographic techniques have been described that allow more accurate evaluation of left ventricular diastolic function. Treatments for left ventricular diastolic dysfunction should focus on the underlying disease etiology as well as on the derangement in left ventricular diastolic function. Although calcium channel blockers and angiotensin-converting enzyme inhibitors have been used clinically to treat diastolic dysfunction, their effects on prognosis remain unproven.
Subject(s)
Diastole/physiology , Ultrasonography, Doppler , Ventricular Dysfunction, Left/diagnostic imaging , Aged , Heart Failure/diagnostic imaging , Heart Failure/etiology , Heart Failure/physiopathology , Humans , Myocardial Contraction/physiology , Reference Values , Ventricular Dysfunction, Left/etiology , Ventricular Dysfunction, Left/physiopathology , Ventricular Function, Left/physiologyABSTRACT
The proximal isovelocity surface area (PISA) color Doppler method with use of a hemielliptic formula is reported to be accurate for quantitating regurgitant volume (RV). However, this formula ideally requires the measurement of 2 or 3 radii and therefore is not widely used clinically. The purpose of this in vitro study was to derive a simple PISA formula for estimating RV with use of a single radius axial to the valve orifice and to compare it with the clinically used single-radius hemispherical formula (2 x pi R(2) x AV x TVI/Vp), where AV is the apparent color Doppler aliasing velocity, R is the PISA color Doppler aliasing radius, TVI is time-velocity integral of the jet by continuous wave Doppler, and Vp is the peak velocity of the jet by continuous wave Doppler. Pulsatile flow studies were performed across a convex curvilinear surface, which more closely approximates the shape of the mitral valve than does a planar surface. Pulse rates (60 to 80 bpm), peak flow velocities (4.0 to 6.0 m/s), and regurgitant orifice areas (0.2 to 1.0 cm(2)) were varied to simulate mitral regurgitation. The AVs were varied from 11 to 39 cm/s, and a single PISA aliasing radius was measured at each AV. Excellent linear correlations were obtained between the PISA radius and the actual RV measured with use of a beaker (r = 0.94 to 0.97, P <.0001). A series of simplified formulas was derived from the regression line of the PISA radius versus the RV. For example, with an AV of 21 cm/s, RV was estimated by a simplified PISA formula (where RV[mL] = 10 x R [mm] - 30) with an accuracy of 3.3 +/- 6.3 mL versus -20.3 +/- 8.7 mL for the standard single-radius PISA method (P <.0001). By using the standard single-radius hemispherical PISA formula, RV was underestimated if the radius was <20 mm. By using simplified regression equations, the PISA radius accurately estimated RV at a PISA radius <20 mm. Clinical studies are necessary to validate this concept.
Subject(s)
Echocardiography, Doppler, Color , Mitral Valve Insufficiency/diagnostic imaging , HumansABSTRACT
Motor vehicle collisions (MVCs) resulting in death have been a serious concern for many years. However, the placement of roadside death memorials (RDMs) at collision sites has become increasingly common in the United States, in the memorialization of those deceased because of MVCs. This practice has been used in numerous countries for hundreds of years. Of the 78 sites observed, most were for males whose deaths had occurred in the past year and were placed by both family members and friends. The sites include the use of a cross and flowers whose meaning is obvious; however numerous other artifacts are found, the meaning of which is less obvious. Some of the functions served by these memorials are to prolong the memory of the deceased in a public place and to communicate with the deceased and to society. RDMs are used by mourners as a way of coping with the sudden and tragic nature of deaths from MVCs.
Subject(s)
Accidents, Traffic/mortality , Adaptation, Psychological , Funeral Rites , Bereavement , Female , Funeral Rites/psychology , Humans , Male , Oklahoma , Safety , TexasABSTRACT
Being involved in the death and dying process as a professional, family member, friend, or patient means taking on an occupational role that will impact one's life. Types of occupational roles associated with death and dying, and how these roles influence the participants, are explored in relation to concepts presented in the Model of Human Occupation. Also addressed is the potential for a care-giving role to bring on distress in the form of role imbalance or role changes, or because of inability to adequately fulfill the role. Suggestions for seeking relative balance within and among roles are presented.
ABSTRACT
CONTEXT: Fenfluramine and dexfenfluramine were voluntarily withdrawn from the market in September 1997 because of reports of an association with heart valve abnormalities. Studies have been limited by lack of comparison with untreated controls. OBJECTIVE: To evaluate cardiovascular status and the prevalence of valvular abnormalities, as assessed by clinical cardiovascular parameters and echocardiography, in patients treated for obesity with dexfenfluramine or phentermine/fenfluramine. DESIGN: Reader-blinded controlled study completed in February 1998. SETTING AND PARTICIPANTS: Twenty-five clinical centers in the United States. Of 1640 enrolled subjects, 1473 were eligible (479 and 455 had taken dexfenfluramine and phentermine/fenfluramine, respectively, continuously for 30 days or more in the previous 14 months, and 539 were untreated matched controls) and provided clinical and echocardiographic data. Mean (SD) age was 47.4 (11.4) years, mean body mass index was 35.0 (7.4) kg/m2, and 74% were women. Mean (SD) duration of therapy was 6.0 (3.3) months (range, 1-18.4 months) in the dexfenfluramine group, and 11.9 (10.4) months (range, 1.4-63 months) in the phentermine/fenfluramine group, while the untreated group had no anorexigen use during the previous 5 years. MAIN OUTCOME MEASURES: Cardiovascular signs and symptoms; echocardiographic evidence of aortic (AR) or mitral (MR) regurgitation according to US Food and Drug Administration (FDA) criteria (AR > or = mild or MR > or = moderate) and by grade; tricuspid and pulmonic valve regurgitation; and aortic, mitral, and tricuspid valve leaflet mobility and thickness, for treated vs untreated subjects. RESULTS: Cardiovascular signs and symptoms were similar among anorexigen-treated and untreated subjects. Prevalence rates and relative risk (RR) of AR were significantly increased in anorexigen-treated patients and were 8.9% in the dexfenfluramine group (RR, 2.18; 95% confidence interval [CI], 1.32-3.59), 13.7% in the phentermine/fenfluramine group (RR, 3.34; 95% CI, 2.09-5.35), and 4.1% in the untreated group (P<.001). No statistically significant differences in prevalence were observed for MR, thickening or decreased mobility of any valve leaflet, calculated pulmonary artery systolic pressure, or left ventricular ejection fraction. Serious cardiac events (including myocardial infarction, congestive heart failure, or ventricular arrhythmia) occurring at any time were not statistically different in treated and untreated subjects (dexfenfluramine, 9.0%; phentermine/fenfluramine, 4.0%; and untreated, 8.4%); and following anorexigen treatment were uncommon (dexfenfluramine, 2.3%; phentermine/fenfluramine, 2.4%, and untreated, 3.3%, when adjusted for the median start date of anorexigen use). CONCLUSIONS: Our data indicate that use of dexfenfluramine and phentermine/fenfluramine is associated with an increase in the prevalence of AR using FDA echocardiographic criteria, but was not associated with an increase in the prevalence of MR using FDA criteria or with serious cardiac events.
Subject(s)
Appetite Depressants/adverse effects , Dexfenfluramine/adverse effects , Fenfluramine/adverse effects , Heart Valve Diseases/chemically induced , Phentermine/adverse effects , Serotonin Agents/adverse effects , Aortic Valve Insufficiency/chemically induced , Aortic Valve Insufficiency/diagnostic imaging , Aortic Valve Insufficiency/epidemiology , Body Mass Index , Echocardiography, Doppler , Female , Heart Valve Diseases/diagnostic imaging , Heart Valve Diseases/epidemiology , Heart Valves/diagnostic imaging , Humans , Logistic Models , Male , Matched-Pair Analysis , Middle Aged , Mitral Valve Insufficiency/chemically induced , Mitral Valve Insufficiency/diagnostic imaging , Mitral Valve Insufficiency/epidemiology , Obesity/drug therapy , Prevalence , Risk , Statistics, NonparametricABSTRACT
Agrobacterium vitis was isolated from roots of 41 of 66 feral Vitis riparia vines collected in three different regions of New York State. Two of the regions were more than 150 km from commercial vineyards. The strains were highly diverse as determined by DNA fingerprinting of the chromosomal region lying between the 16S and 23S rRNA genes. Of 24 strains examined, 15 different fingerprints were generated, and none was identical to fingerprints generated by previously identified groups of tumorigenic A. vitis strains. Results of physiological tests that were done to characterize strains from V. riparia conformed closely to those expected for A. vitis, except that 23 of 26 strains did not utilize tartrate. All strains were nontumorigenic, did not hybridize with a probe consisting of T-DNA genes, did not utilize octopine or nopaline, and carried zero to three plasmids. Of 26 strains, 7 inhibited A. vitis strain K306 from causing galls at wound sites on grape as well as or better than a previously studied nontumorigenic A. vitis strain, F2/5, that is known to have biological control activity.
ABSTRACT
There has been a resurgence of interest in the information provided by indirect calorimetry. In the past calorimetry was considered a research technique, but technological advances have made it applicable in many clinical situations. Recent clinical applications of this technique have been examined in this review.
Subject(s)
Calorimetry, Indirect , Acquired Immunodeficiency Syndrome/metabolism , Child , Child, Preschool , Energy Metabolism/drug effects , HIV Seropositivity/metabolism , Humans , Infant , Infant, Newborn , Kidney Diseases/metabolism , Liver Diseases/metabolism , Obesity/metabolismABSTRACT
The purpose of this retrospective study was to examine 732 consecutive patients who underwent dobutamine stress echocardiography (DSE) in order to compare the safety and result profiles of this test between women versus men and in patients > or = 75 and < 75 years of age. Our study included 416 women (57%) and 316 men (43%; mean age 62 +/- 12 years [range 16 to 93]). Patients were divided into 3 age groups: (1) group I (n = 179): < 55 years (mean 47 +/- 6), (2) group II (n = 447): 55 to 74 years (mean 64 +/- 5), and (3) group III (n = 106): > or = 75 years (mean 80 +/- 4). DSE was more likely to have negative results in women than in men (prevalence of positivity = 20% vs 31%, p = 0.001), but DSE had a similar safety profile in both genders. Women required lower doses of dobutamine and atropine to reach an end point. There was a similar incidence of test positivity in older and younger patients (23% in group I, 24% in group II, and 30% in group III, p = NS). DSE was generally a safe test in patients > or = 75 years, but there was a different safety profile in the elderly group compared with younger patients--specifically, more frequent asymptomatic hypotension (7% in group I, 13% in group II, and 25% in group III, p = 0.0002) and ventricular arrhythmias (26% in group I, 30% in group II, and 41% in group III, p = 0.04), but less frequent chest pain (32% in group I, 23% in group II, and 17% in group III, p = 0.009). Multivariate analysis suggested that the baseline usage of beta blockers was also a major determinant of the safety and ischemia profile during DSE. In conclusion, there were significant gender- and/or age-specific differences in the safety and test result profile of DSE. These differences should be considered when performing or interpreting DSE, particularly in women and in patients aged > or = 75 years.
Subject(s)
Coronary Disease/diagnosis , Dobutamine , Echocardiography/adverse effects , Adolescent , Adrenergic beta-Antagonists/therapeutic use , Adult , Age Factors , Aged , Aged, 80 and over , Atropine , Echocardiography/methods , Female , Humans , Hypotension/chemically induced , Male , Middle Aged , Multivariate Analysis , Retrospective Studies , Sex Factors , Treatment Outcome , Ventricular Fibrillation/chemically inducedABSTRACT
Although increasing the high school graduation rate is now a national goal, requirements for graduation are not set at the national level. And, although the goal is said to include students in special education programs, what high school graduation means for these students is not clear. We collected documentation from state departments of education to examine high school graduation requirements for students in general, and for students with disabilities. Forty-four states use Carnegie course unit requirements ranging from 10.35 to 24.00 credits. Seventeen states currently have requirements for either a minimum competency test or an exit exam. Local education agencies in several states have the option of establishing more stringent requirements than called for in state guidelines. Exit documents that are awarded to students with disabilities (e.g., standard diplomas, modified diplomas, certificates of attendance) also vary from state to state, with similar requirements sometimes earning different types of exit documents in different states. These inconsistencies in graduation requirements and their implications for students with learning disabilities are discussed.
Subject(s)
Disabled Children/legislation & jurisprudence , Education, Special/legislation & jurisprudence , Educational Measurement , Learning Disabilities/diagnosis , Adolescent , Educational Status , Female , Humans , Learning Disabilities/classification , Male , United StatesABSTRACT
ABSTRACT Agrocin-minus mutants of nontumorigenic Agrobacterium vitis strain F2/5 controlled grape crown gall as well as the wild-type strain, indicating that agrocin is not a major factor in the mechanism of biological control. Relative levels of attachment to grape cells by tumorigenic and biocontrol strains were also measured. Attachment of tumorigenic strains (CG49 and K306) and biological control strains (F2/5 and agrocin-minus mutant 1077) was often reduced when mixtures of the strains were applied. However, high populations (10(3) to 10(5) CFU/ml) of all strains attached following mixed inoculations, suggesting that competition for attachment sites is also not a factor in the mechanism of biological control. Transfer of T-DNA to grape by CG49 was prevented or greatly inhibited in the presence of F2/5 or 1077 as measured by expression of the GUS reporter gene. The Ti plasmid virulence genes, however, were induced by exudates from grape shoots that had been inoculated with F2/5. Sonicated and autoclaved preparations of F2/5 and 1077 did not control crown gall or inhibit T-DNA transfer. Control by F2/5 is specific to grape, since gall formation on tomato, sunflower, and Kalanchoe daigremontiana were not inhibited.
ABSTRACT
The indolizidine alkaloid swainsonine, a potent inhibitor of Golgi alpha-mannosidase II, has been shown to reduce tumor cell metastasis, enhance cellular immune responses, and reduce solid tumor growth in mice. In our previous Phase I study, swainsonine administered by 5-day continuous infusion inhibited L-phytohemagglutinin-reactive N-linked oligosaccharide expression on peripheral blood lymphocytes. Significant toxicities included edema and elevated serum aspartate aminotransferase (AST). One patient with head and neck cancer had objective (>50%) tumor remission. Two patients showed symptomatic improvement. The objectives of this Phase IB trial were to examine the pharmacokinetics, toxicities, and biochemical effects of bi-weekly oral swainsonine at escalating dose levels (50-600 microgram/kg) in 16 patients with advanced malignancies and 2 HIV-positive patients unsuitable for conventional therapy. Eastern Cooperative Oncology Group performance status was =2. The maximum tolerated dose was defined as 300 microgram/kg/day due primarily to serum AST abnormalities and dyspnea. Other adverse events present in >20% of patients included increase in serum AST (all patients), fatigue (n = 9), anorexia (n = 6), dyspnea (n = 6), and abdominal pain (n = 4). Inhibition of Golgi alpha-mannosidase II occurred in a dose-dependent manner. Examination of immunological parameters revealed a transient decrease in CD25(+) peripheral blood lymphocytes and, in seven of eight patients, an increase in CD4(+):CD8(+) ratios at 2 weeks. Serum drug levels peaked 3-4 h following a single oral dose in most patients and were proportional to dose at levels >/=150 microgram/kg. We conclude that oral swainsonine is tolerated by chronic intermittent administration at doses up to 150 microgram/kg/day. Adverse events considered drug related were similar to those observed in the infusional study but with fatigue and neurological effects also noted. Investigations of alternative dosing schedules with low starting doses are suggested for further clinical testing.
Subject(s)
Antineoplastic Agents, Phytogenic/adverse effects , Antineoplastic Agents, Phytogenic/pharmacokinetics , Neoplasms/drug therapy , Swainsonine/adverse effects , Swainsonine/pharmacokinetics , Adult , Aged , Animals , Antineoplastic Agents, Phytogenic/blood , Aspartate Aminotransferases/blood , Carbohydrate Conformation , Carbohydrate Sequence , Dose-Response Relationship, Drug , Edema/chemically induced , Female , Head and Neck Neoplasms/drug therapy , Humans , Male , Mannosidases/antagonists & inhibitors , Mice , Middle Aged , Molecular Sequence Data , Oligosaccharides/chemistry , Oligosaccharides/metabolism , Swainsonine/blood , alpha-MannosidaseABSTRACT
To define the clinical utility of the color Doppler proximal isovelocity surface area (PISA) method for estimating regurgitant stroke volume (SV), 160 regurgitant lesions were evaluated in 104 patients with mitral (MR), aortic (AR), and tricuspid (TR) regurgitation. Regurgitant SV by PISA was calculated as 2 pi R2 x V x (time-velocity integral/peak flow velocity), where R is the radius corresponding to the first blue-red interface velocity of the maximal PISA during the cardiac cycle. The time-velocity integral and peak flow velocity from the continuous-wave Doppler recording of the regurgitant jet were used to correct PISA for phasic variations in regurgitant flow. Fifteen lesions were excluded because of difficulty in tracing the continuous-wave Doppler regurgitant curve. Among 145 remaining regurgitant lesions, PISA was measurable in 50 (78%) of 64 cases of MR and 24 (69%) of 35 cases of TR but in only 12 (26%) of 46 cases of AR (p < 0.001). Regurgitant SV by PISA correlated modestly well with jet area/atrial area in all atrioventricular valve lesions (MR: r = 0.55; TR: r = 0.65; p < 0.001). However, the correlation improved if only central jets were considered (MR: r = 0.70; TR; r = 0.75; p < 0.001). These findings are not unexpected because jet area/atrial area underestimates the true severity of regurgitation in cases of eccentric (wall-impinging) jets. PISA was detected in all severe cases of regurgitation but in only 64% of cases of mild MR, 45% of cases of mild TR, and 6% of cases of mild AR (p < 0.01). The color Doppler PISA method is clinically useful in estimating regurgitant SV in MR and TR, including mild cases, but is less useful in AR.
Subject(s)
Aortic Valve Insufficiency/diagnostic imaging , Echocardiography, Doppler, Color/methods , Mitral Valve Insufficiency/diagnostic imaging , Stroke Volume , Tricuspid Valve Insufficiency/diagnostic imaging , Adolescent , Adult , Aged , Aged, 80 and over , Algorithms , Chi-Square Distribution , Child , Female , Humans , Linear Models , Male , Middle AgedABSTRACT
To investigate the relationship between left ventricular cavity geometry and dynamic intracavitary left ventricular obstruction occurring during dobutamine stress echocardiography, we evaluated 44 patients who underwent dobutamine stress echocardiography. Dynamic intracavitary left ventricular obstruction appeared in 10 (23%) patients (Group 1), and was absent in the remaining 34 patients (Group 2), during dobutamine stress echocardiography. The ratio of the apicalto-narrowest mid-left ventricular minor-axis dimension (D1/D2), as an index of the left ventricular cavitary geometry, was measured in the baseline two dimensional apical long-axis view. The left ventricular out-flow blood Doppler velocity was measured in the apical long-axis or five-chamber view at each stage during dobutamine infusion. Left ventricular end-systolic dimension was smaller (21 +/- 4 mm v 29 +/- 6 mm; p< .01), percent fractional shortening of the left ventricle was greater (51 +/- 4% v 39 +/- 8%, P>.01), and D1/D2 was greater (1.13 +/- 0.08 v.0.96 +/- 0.09; p < .0001) in Group 1 than in Group 2 in the baseline echocardiogram. Maximal out flow blood Doppler velocity during dobutamine infusion correlated moderately with percent fractional shortening of the left ventricle (r = .53; P < .01) and D1/D2 (r = .60; P < .0001). Dynamic intracavitary left ventricular obstruction, defined as an elevated intracavitary Doppler flow velocity with late-systolic peaking, was not related to the presence of left ventricular hypertrophy or the development of hypotension during dobutamine infusion. We conclude that dynamic left ventricular intracavitary obstruction during dobutamine infusion is associated with a characteristic (narrower-waisted) left ventricular cavitary geometry and increased contractility.
Subject(s)
Cardiotonic Agents , Dobutamine , Echocardiography , Ventricular Function, Left , Ventricular Outflow Obstruction/diagnostic imaging , Adult , Aged , Blood Pressure , Echocardiography, Doppler , Female , Humans , Laser-Doppler Flowmetry , Male , Middle Aged , Ventricular Outflow Obstruction/physiopathologyABSTRACT
BACKGROUND: Gender differences in cardiac size have been described in normal humans and animals and in response to pressure overload. To examine the influence of gender on the left ventricular response to pressure overload, clinical, haemodynamic, and echocardiographic data were analysed in the 232 adults with isolated aortic stenosis enrolled in the Balloon Valvuloplasty Registry. METHODS AND RESULTS: There were 92 men (mean (SD) age 75 (11) years) and 140 women (79 (9) years; P = 0.002). Women had similar symptoms (New York Heart Association class) but lower overall functional status than men (P = 0.008). Catheterisation data showed similar valve area indices (mean (SD) (0.30 (0.09) in men and 0.31 (0.13) cm/m2 in women) but higher peak and mean gradients in women (peak 74 (30) v 63 (22) mm Hg; mean 61 (21) v 54 (18) mm Hg; both P < or = 0.01). On M mode echocardiography women had greater septal and posterior wall thickness but similar cavity diameter, after normalising dimensions to body surface area, resulting in higher relative wall thickness (0.60 (0.20) v 0.50 (0.15); P = 0.0002). Left ventricular mass index was similar in women and men (166 (59) v 159 (50) gm/m2 respectively), however, the prevalence of left ventricular hypertrophy according to sex specific criteria was 54% in men and 81% in women (P = 0.0001). Multiple logistic regression models that adjusted for age, functional status, fractional shortening, and left ventricular systolic pressure found the presence or absence of hypertrophy to be independently associated with gender (P < or = 0.002). Left ventricular systolic function tended to be better in women, who had a higher cardiac index (2.5 (0.8) v 2.3 (0.6) 1/min/m2; P = 0.01), left ventricular peak systolic pressure (211 (36) v 192 (35) mm Hg; P = 0.0001), and echo fractional shortening (32 (13) v 28 (12)%; P = 0.05); however, these differences were reduced when patients with regional wall motion abnormalities were excluded. CONCLUSIONS: In this population of elderly patients undergoing balloon dilatation of isolated aortic stenosis, left ventricular chamber geometry was different in men and women. Because this was a selected population, gender should be further evaluated as a possible determinant of the cardiac adaptation to chronic pressure overload.