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Biomedical subjects

M Kupari

Publications and source records attributed to M Kupari.

At least 55 records · Page 3Linked to original sources
PubMed1995

Cross sectional profiles of systolic flow velocities in left ventricular outflow tract of normal subjects.

BACKGROUND: The idea that blood passes through the left ventricular outflow tract with a flat velocity profile has recently been questioned. OBJECTIVE: To construct flow velocity profiles by magnetic resonance imaging over the whole cross sectional subaortic flow area in normal subjects. SUBJECTS: Nine people without heart disease aged 25 to 56. DESIGN: Cardiac gated cine magnetic resonance images were produced with a 1.0 T magnet perpendicular to the longitudinal axis of the left ventricular outflow tract 0.5 to 1.0 cm below the aortic annulus in mid-systole. Velocity was encoded every 30-40 ms throughout systole in the direction of flow perpendicular to the image plane. MAIN OUTCOME MEASURES: Systolic velocity-time curves reconstructed in nine different regions (area of each circle 0.2 cm2) of the subaortic flow area. The systolic peak velocity and the mean flow rate were taken as indices of regional flow. RESULTS: The spatial inhomogeneity of the peak velocity, calculated as the percentage ratio of the range of the regional measurements to their mean, averaged 18.2% (5.0%), and the inhomogeneity of the mean flow rate was 19.2% (3.5%). There were significant trends (P < 0.05) across the regional measurements towards highest peak velocities and mean systolic flow rate in the anteromedial sector of the subaortic flow area. The peak systolic velocity in the centre of the flow area averaged 98 (8) cm/s while the coincident spatial average was 94 (5) cm (P = 0.013). CONCLUSIONS: The distribution of systolic velocities across the left ventricular outflow tract is skewed towards fastest flow in the anteromedial sector of the flow area. The peak velocities measured in the centre of the flow area slightly overestimate the coincident spatial average velocities.

Adult↗
PubMed1995

Skewness of instantaneous mitral transannular flow-velocity profiles in normal humans.

The spatial distribution of instantaneous diastolic flow velocities across the mitral annulus was studied with cardiac gated cine magnetic resonance imaging in 10 healthy persons aged 26-46 yr. Velocity encoding used two interleaved gradient echo pulse sequences with velocity sensitivity in the direction of flow perpendicular to the annular imaging plane. Velocity maps were reconstructed at 30- to 43-ms intervals throughout diastole. Velocity-time curves and mean flow rates were determined in five regions of the mitral annulus using a 0.6-cm2 measurement area. The spatial velocity minimum was consistently in the anterolateral commissural area, whereas the maximum was in the anterior annulus in early diastole shifting posteromedially in late diastole. The mean flow rate (+/- SD) averaged 18.4 +/- 8.1 ml.s-1.cm-2 of annular area centrally, 18.3 +/- 7.2 ml.s-1.cm-2 anteriorly, 16.9 +/- 7.4 ml.s-1.cm-2 posteriorly, 13.0 +/- 7.7 ml.s-1.cm-2 in the anterolateral commissural area, and 23.0 +/- 7.3 ml.s-1.cm-2 in the posteromedial commissural area (P < 0.001). We conclude that mitral transannular flow shows marked spatial inhomogeneity in normal humans. The skewness of flow profiles compromises the use of local velocity measurements as indexes of left ventricular filling.

Adult↗
PubMed1995

Effect of negative intrathoracic pressure on left ventricular pressure dynamics and relaxation.

To investigate the effect of a fall of intrathoracic pressure on left ventricular (LV) hemodynamics and relaxation, simultaneous micromanometric recordings of LV and aortic pressures were performed at rest and during two graded Mueller maneuvers in 16 patients undergoing cardiac catheterization for aortic valve stenosis (n = 8) or chest pain (n = 8). The reductions (means +/- SE) of airway pressure during the lesser and greater maneuvers were 26 +/- 1 and 42 +/- 1 mmHg, respectively. Simultaneously, LV isovolumic-developed pressure increased by 9 +/- 3 and 21 +/- 4 mmHg, respectively (P < 0.03 for both). During the greater maneuver, the individual changes of the time constant of LV isovolumic relaxation (tau) correlated with the changes of LV isovolumic-developed pressure (r = 0.73; P = 0.002). In patients with a > 20-mmHg rise in isovolumic-developed pressure, tau increased by 10.3 +/- 4.6 ms. By multiple-regression analysis, the change of tau was related directly to the change of isovolumic-developed pressure (standardized coefficient beta = 0.80; P = 0.001) and inversely related to the resting systolic LV-aortic pressure gradient (beta = -0.37; P = 0.050). The other hemodynamic changes were independent of aortic valve stenosis. In conclusion, during the Mueller maneuver, the LV isovolumic contraction load increases and tau lengthens, particularly with higher elevations of LV systolic load.

Adult↗
PubMed1995

Results of cardiovascular surgery in the Marfan syndrome. A retrospective study of 49 patients.

To evaluate the outcome of cardiovascular surgery in the Marfan syndrome, the records of 49 patients (median age 35 years) who underwent 60 operations were reviewed. Primary surgery was elective in 39 patients and emergency in ten. Non-dissecting aneurysm with diameter 4-19 cm was present in 34 cases and distal, isolated aneurysm in four. In eight cases there was type A acute aortic dissection with median diameter 5.0 cm. One patient was operated on for mitral valve insufficiency, one for ventricular septal defect and one (acute) for endocarditis. Composite grafts were used for aortic root reconstruction. Operative complications occurred in 24% of the patients. The 30-day survival was 92%. There were five (10%) late deaths. Survival after a median of 8 years postoperatively was 82%. The early and late results of cardiovascular surgery in the Marfan syndrome thus are concluded to be generally favourable. As late reoperation frequently is needed, however, close monitoring is advocated even after successful primary surgery.

Adolescent↗
PubMed1994

Echocardiographic evidence of left ventricular hypertrophy in a general aged population.

The purpose of this study was to measure the frequency of left ventricular (LV) hypertrophy in old age. Random subjects born in 1904, 1909, and 1914 (n = 501), and 76 born in 1920 to 1935 were studied. All subjects underwent clinical and echocardiographic investigation. An electrocardiogram was obtained in 449 subjects. Complete data for calculation of LV mass corrected for body size were available in 422 of the studied subjects (73%). LV hypertrophy was defined as calculated LV mass exceeding either an internal standard of the Helsinki Aging Study, earlier published limits from the Framingham Heart Study, or criteria from Devereux et al. LV wall thickness and mass were positively related to age. Hypertrophy was present in both sexes, the rate even exceeding 70% in the oldest cohort aged 85 to 86 years using the Framingham and Devereux limits. LV hypertrophy (LV mass exceeding defined limits after correction for body height) was significantly and independently related to age, systolic blood pressure, body mass index, and mitral regurgitation. A sustained apex beat, third heart sound, and electrocardiographic changes were significantly more frequent in the group with echocardiographic hypertrophy, although with considerable overlapping. The fourth heart sound was unrelated to hypertrophy. Use of age-independent criteria result in an extremely high prevalence of LV hypertrophy in old age. This is partly due to age-related diseases increasing LV mass, but also partly to an independent effect of age. The usefulness of clinical signs for detecting LV hypertrophy is limited in old age.

Aged↗
PubMed1994

Autonomic nervous system and cardiac involvement in familial amyloidosis, Finnish type (FAF).

Familial amyloidosis, Finnish type (FAF), is a gelsolin-related inherited systemic amyloidosis. We report autonomic nervous system and cardiac findings in a study of 30 FAF patients (18 females, 12 males aged 27-74 years; mean 53.9 years). Cardiovascular reflex tests showed a significant decrease in heart rate variation in FAF patients compared with healthy controls. Orthostatic hypotension was found in 9 of 28 FAF patients, but only in 3 of 69 controls. Signs of amyloid cardiopathy were rare at clinical examination and in radio-, echocardio- and electrocardiographic examinations. Histological and immunohistochemical studies revealed amyloid deposition and immunoreactivity against the gelsolin-related FAF amyloid subunit in autonomic nervous system structures and in cardiac tissue in 3 autopsied FAF patients. The results show that minor autonomic nervous system dysfunction can be found in FAF, while clinically significant amyloid cardiopathy or autonomic neuropathy is not characteristic of this type of amyloidosis.

Adult↗
PubMed1994

Acute alcohol intake decreases short-term heart rate variability in healthy subjects.

1. The acute effects of a moderate dose of ethanol (1g/kg body weight) on heart rate and blood pressure variability and baroreflex sensitivity were studied in 12 healthy male subjects in a juice-controlled experiment. Electrocardiographic and finger blood pressure data were recorded and stored in a minicomputer during 5 min of controlled breathing (15 cycles/min) and during deep breathing (5 s inspiration, 5 s expiration, four cycles) before drinking and hourly thereafter for 3 h. 2. Mean breath alcohol concentration rose to 18.9 mg/100 ml. In the time domain analysis, the root mean square difference of successive R-R interval decreased significantly with ethanol as compared with the juice experiment. The difference remained statistically significant even after adjustment for the shorter R-R interval after alcohol. In the frequency domain analysis the high-frequency (0.15-0.5 Hz) spectral power showed a significant decrease after alcohol intake. Also, the index of sensitivity of the baroreceptor reflex (square root of R-R interval power/systolic blood pressure power) decreased significantly in the high-frequency component. Ethanol did not change finger systolic blood pressure, and power spectral analysis did not show significant variability in blood pressure. 3. These data indicate that acute intake of moderate amounts of alcohol causes a significant decrease in heart rate variability owing to diminished vagal modulation of the heart rate.

Adult↗
PubMed1994

Left ventricular function in children with the Marfan syndrome.

Aortic dilatation and heart valve lesions are common in the Marfan syndrome but whether primary alterations occur in left ventricular (LV) function has not been studied hitherto. LV size, mass and systolic as well as diastolic function were studied by M-mode and Doppler echocardiography and cine magnetic resonance imaging in 22 Marfan children aged 3.0-15.4 years and in 22 age-matched healthy children. No child had significant valve disease. Heart rate and systolic blood pressure were comparable in the groups but diastolic blood pressure was higher in the controls (67 +/- 7 mmHg vs 62 +/- 8 mmHg, P = 0.030). No statistically significant differences were found in LV size, mass or systolic function. The Marfan children had slower LV peak diameter lengthening rates (106 +/- 27 mm.s-1 vs 132 +/- 29 mm.s-1, P = 0.004), prolonged relaxation times (155 +/- 22 ms vs 140 +/- 19 ms, P = 0.023), slower deceleration of the early transmitral velocity (580 +/- 144 cm.s-1 vs 720 +/- 160 cm.s-2, P = 0.006), and smaller early-to-late peak velocity ratios (1.99 +/- 0.40 vs 2.29 +/- 0.46, P = 0.031). These data indicate that LV early diastolic function (relaxation) is impaired in the Marfan syndrome. Weakened elastic recoil due to the underlying connective tissue abnormality may best explain this novel observation.

Child↗
PubMed1994

Predictors of left ventricular mass in old age: an echocardiographic, clinical and biochemical investigation of a random population sample.

The potential predictors of left ventricular mass in old age were studied in a random sample of people born in 1904, 1909, 1914 (n = 501) and 1920-35 (n = 76). Data on the left ventricle with mass calculation, quantitative data on valve disorders and biochemical data were collected. Left ventricular mass (corrected for height) was positively related to male gender, age, body mass index and systolic blood pressure. It was also significantly higher in the presence of aortic valve calcification, a low velocity ratio (indicating aortic valve obstruction), and aortic or mitral regurgitation. In men, left ventricular mass was higher in the presence of coronary artery disease and inversely related to serum high density lipoprotein cholesterol. In multivariate analysis, independent predictors of left ventricular mass without sex interaction were age (standardized coefficient beta = 0.23, P = 0.000), male gender (beta = 0.38, P = 0.000), body mass index (beta = 0.22, P = 0.000), systolic blood pressure (beta = 0.21, P = 0.000), velocity ratio (beta = -0.11, P = 0.010), detectable aortic regurgitation (beta = 0.11, P = 0.014) and moderate-to-severe mitral regurgitation (beta = 0.21, P = 0.000). Thus, the increase in left ventricular mass with age can largely be related to discrete predictors. The impact of valve disorders is substantial.

Age Factors↗
PubMed1994

Factors associated with calcific aortic valve degeneration in the elderly.

This study aimed at identifying factors influencing aortic valve calcification in old age. Echocardiographic and Doppler characteristics of the aortic valve were compared with possible clinical and biochemical predictors in 501 people aged 75-86 years and in 76 aged 55-71. Slight calcification was seen in 222 people (40%) and severe calcification in 72 (13%); 21 people had moderate or severe aortic stenosis. Age (P = 0.000) and serum parathyroid hormone (P = 0.015) were higher and body mass index lower (P = 0.002) in the presence of aortic valve calcification. In multivariate analysis, age (P = 0.000), hypertension (P = 0.005) and body mass index (P = 0.005) were independent predictors of aortic valve calcification, and age (P = 0.022) and serum ionized calcium (P = 0.037) of valve stenosis. The odds ratio (95% confidence interval) for valve calcification was 1.89 (1.42-2.50) for a 10-year increase in age, 1.74 (1.19-2.55) in the presence of hypertension, and 1.39 (1.10-1.76) for a 5 kg.m-2 decrease in body mass index. Sex, smoking, diabetes, serum lipids and insulin were unrelated to valvular calcification. These data suggest that leanness and a history of hypertension increase the likelihood of senile aortic valve calcification. Calcium metabolism may also be of significance. The mechanisms of these associations deserve further study.

Aged↗
PubMed1994

Age-dependent influence of heart rate on Doppler indexes of left ventricular filling.

BACKGROUND AND OBJECTIVE: The Doppler indexes of left ventricular filling are related to age and heart rate. The aim of this study was to assess whether the influences of heart rate and age interactions (that is, whether the effect of heart rate on the Doppler indexes) is modified by age. SUBJECTS AND METHODS: The effects of atropine-induced heart rate increases on the transmitral velocities were compared in 10 younger healthy subjects aged 26-38 years and 12 older healthy subjects aged 50-67 years. RESULTS: With a comparable total rise in heart rate (on average 20 beats min-1), the peak early diastolic velocity decreased likewise in both groups (from 66 +/- 9 to 57 +/- 9 cm s-1 in the younger age group and from 58 +/- 15 to 47 +/- 13 cm s-1 in the older age group). The peak atrial velocity remained unaltered in the older group (53 +/- 16 vs. 52 +/- 14 cm s-1) but rose from 33 +/- 6 to 44 +/- 12 cm s-1 in the younger (P = 0.02). The early-to-atrial peak velocity ratio decreased from 1.2 +/- 0.6 to 1.0 +/- 0.4 cm s-1 in the older subjects and from 2.0 +/- 0.5 to 1.4 +/- 0.5 cm s-1 in the younger subjects (P = 0.01). Changes in the other Doppler indexes were similar in both groups. CONCLUSIONS: The effect of heart rate on certain Doppler indexes of left ventricular filling is age-dependent. The peak velocity ratio cannot be interpreted without adjusting for heart rate in younger subjects, whilst in older people heart rate variation is of less importance.

Adult↗
PubMed1994

Left ventricular size, mass, and function in relation to angiotensin-converting enzyme gene polymorphism in humans.

Angiotensin-converting enzyme (ACE) exhibits genetic variation related to insertion/deletion (I/D) polymorphism in intron 16 of the ACE gene. The DD genotype results in high ACE activity and is overrepresented in diseases characterized by left ventricular (LV) hypertrophy and dysfunction. We studied whether the ACE gene polymorphism predicts LV mass or function in the absence of heart disease. Polymerase chain reaction of leukocyte DNA was used to determine the I/D genotype, and M-mode and Doppler echocardiography were used to quantify LV mass and function in 86 human subjects, 36-37 yr of age. All were free of clinical heart disease. The LV mass-to-body height ratio averaged 99 +/- 19 (SD) g/m in subjects with the II genotype (n = 25), 99 +/- 30 g/m in those with the ID genotype (n = 35), and 94 +/- 24 g/m in those with the DD genotype (n = 26; P = 0.790). The indexes of LV systolic and diastolic function were also unrelated to the ACE genotype. We conclude that in the absence of heart disease the ACE gene variation has no major influence on LV mass or function that is detectable at echocardiography.

Adult↗
PubMed1994

Atrial septal defect blunts the impairment of left ventricular function during the Mueller maneuver.

To investigate whether atrial septal defect (ASD) modifies the left ventricular (LV) hemodynamic response to a fall of intrathoracic pressure (Mueller maneuver), we studied 15 patients with an uncomplicated ASD and 16 healthy control subjects. LV function was measured by M-mode and Doppler echocardiography at rest and during the maneuver. Indicator-dilution technique was used to quantify the pulmonary-to-systemic flow ratio. During comparable changes (means +/- SE) of intrathoracic pressure (-33 +/- 2 mmHg in persons with ASD vs. -34 +/- 2 mmHg in those without), LV systolic function and filling diminished in both groups but patients with ASD showed smaller reductions in LV stroke dimension (-0.9 +/- 0.5 vs. -2.5 +/- 0.4 mm; P = 0.016), peak diameter shortening rate (-4 +/- 2 vs. -12 +/- 2 mm/s; P = 0.007), transmitral velocity-time integral (-1.0 +/- 0.3 vs. -2.2 +/- 0.4 cm; P = 0.022), and cardiac output (-6 +/- 3 vs. -18 +/- 3%; P = 0.029). The pulmonary-to-systemic flow ratio increased from 2.1 +/- 0.1 to 2.6 +/- 0.2 in the ASD group (P = 0.014). In conclusion, LV function diminishes significantly in healthy persons during the Mueller maneuver. In patients with ASD, the changes are directionally similar but quantitatively smaller. An interatrial communication mitigates the impairment of LV function after an acute and sustained drop of intrathoracic pressure.

Adult↗
PubMed1994

Relation of aortic stiffness to factors modifying the risk of atherosclerosis in healthy people.

To identify factors predicting aortic stiffness, we studied the modulus of elasticity of the thoracic aorta in relation to sex, obesity, blood pressure, physical activity, smoking, ethanol consumption, salt intake, and serum lipid and insulin levels in 55 healthy people born in 1954. A transverse cine magnetic resonance image of the thoracic aorta was made, and the modulus of elasticity was determined as brachial artery cuff pulse pressure/aortic strain, where strain was determined as the ratio of pulsatile aortic luminal area change to the diastolic luminal area. The average of measurements made in the ascending and descending aorta was used as the elastic modulus of the thoracic aorta. Habitual physical activity, smoking, and alcohol use were quantified by 2-month prospective daily recording and salt intake by 7-day food records. The aortic elastic modulus ranged from 100 to 2091 10(3) dyne/cm2 (median, 390 10(3) dyne/cm2). In multiple regression analyses, log10 aortic elastic modulus was related directly to mean blood pressure (standardized coefficient [beta] = .37, P = .002), serum high-density lipoprotein cholesterol (beta = .36, P = .012), square root of daily energy expenditure in physical activity (beta = .33, P = .005), and log10 serum insulin (beta = .27, P = .047) and inversely to serum low-density lipoprotein cholesterol (beta = -.26, P = .035). A relation to salt intake was also observed, but the regression slope was dependent on mean blood pressure (P = .005 for interaction). These data suggest that many modifiable constitutional and lifestyle characteristics may contribute to the stiffness of the thoracic aorta.

Adult↗
PubMed1994

Correlates of left ventricular mass in a population sample aged 36 to 37 years. Focus on lifestyle and salt intake.

BACKGROUND: Echocardiographically determined left ventricular (LV) mass predicts adverse cardiovascular events in the general population. We have assessed the correlates of LV mass in a population-based study focusing on lifestyle and salt intake. METHODS AND RESULTS: A random sample of 120 persons born in 1954 was invited; 93 (42 men) entered the study. The subjects' physical activity and alcohol, tobacco, and coffee consumption were quantified by 2-month dairy follow-up, and sodium intake was quantified by 7-day food records. Blood pressure was averaged for casual cuff measurements made 2 months apart. LV mass was determined by M-mode echocardiography, and stroke volume was determined by Doppler. Hematocrit and serum insulin were measured. In multiple linear regression analysis, LV mass was related positively and independently (P < .05) to body weight, systolic blood pressure, stroke volume, sodium intake, hematocrit, and energy expenditure in leisure-time physical activity. Additional analyses showed that the relation of LV mass to daily sodium intake depended on blood pressure (P < .001 for the interaction); the multiple regression coefficient (+/- SE) was 0.41 +/- 0.11 g.mEq-1 x d-1 (P = .001) in subjects with systolic blood pressure above the population median but statistically nonsignificant (-0.15 +/- 0.10 g.mEq-1 x d-1) in those with lower blood pressure. LV mass was clearly elevated only in persons with both blood pressure and sodium intake above the population medians. CONCLUSIONS: Body weight, blood pressure, stroke volume, sodium intake, physical activity, and hematocrit are independent predictors of LV mass among unselected persons aged 36 to 37 years. The synergistic interaction of dietary salt with blood pressure suggests that high sodium intake may sensitize the heart to the hypertrophic stimulus of pressure load. Prospective studies are needed to confirm these cross-sectional associations.

Adult↗
PubMed1994

Prevalence and predictors of audible physiological third heart sound in a population sample aged 36 to 37 years.

BACKGROUND: A physiological third heart sound (S3) is common in youth but allegedly very rare after the age of 40 years. The mechanism of its disappearance is not known. The aim of this work was to study the prevalence and predictors of physiological S3 in a population-based sample of persons approaching 40 years of age. METHODS AND RESULTS: A random sample of 120 persons born in 1954 was invited; 93 (42 men) entered the study. Their physical activity, alcohol and tobacco consumption, and salt intake were quantified by diary follow-up. The presence of an S3 was determined by auscultation and confirmed by phonocardiography. Left ventricular (LV) size, mass, and systolic function were assessed by M-mode echocardiography and LV filling by Doppler velocimetry of transmitral flow. An audible S3 was detected in 22 subjects, 1 of whom had heart disease. The prevalence of physiological S3 was 23.1%. Subjects with physiological S3 had a lower body mass index (22.3 +/- 2.8 versus 24.6 +/- 4.1 kg/m2 [mean +/- SD], P = .005), lower heart rate (63 +/- 7 versus 68 +/- 10 beats per minute, P = .015), higher peak early diastolic transmitral velocity (67 +/- 10 versus 58 +/- 8 cm/s, P = .002), and higher acceleration of early diastolic velocity (717 +/- 148 versus 622 +/- 122 cm/s2, P = .012) than those without S3. No differences were noted in the lifestyle characteristics, blood pressure, or LV mass and systolic function. Body mass index and peak early diastolic transmitral velocity were independent predictors of physiological S3 in logistic regression analysis. CONCLUSIONS: Nearly one fourth of persons approaching their forties still have an audible physiological S3. The presence of S3 is predicted by leanness and a high early diastolic LV inflow velocity; the disappearance of S3 is unlikely to be secondary to increasing blood pressure and relative LV hypertrophy, as is widely presented, but reflects a more primary age-related alteration of LV early diastolic function.

Adult↗
PubMed1993

Relation of left ventricular function to habitual alcohol consumption.

Left ventricular (LV) dysfunction is a frequent finding in chronic alcoholic subjects. LV function's relation to alcohol use in the general population, where low and moderate consumption predominate, was studied in this work. A random sample of 120 people born in 1954 was invited to participate in the study, and 93 (42 men and 51 women) enrolled. Ethanol use was studied by 2-month daily recording of all alcoholic drinks; smoking and physical activity were quantified likewise, and salt intake by 7-day food records. Subsequently, subjects underwent an LV examination by M-mode echocardiography, and a transmitral flow velocity study by pulsed Doppler ultrasound. The relations of LV measurements to alcohol use were studied by multiple linear regression adjusting for sex, body size, blood pressure, heart rate, smoking, physical activity and dietary salt intake. No subject had clinical heart disease. The average daily ethanol consumption ranged from 0 to 1.2 g/kg of body weight (median 0.2). Statistically significant associations with square-root daily ethanol use were found for LV end-systolic diameter (regression coefficient [b] +/- SE 4.0 +/- 1.5 mm/square root of g/kg; p < 0.01), fractional shortening (b = -3.9 +/- 1.8%/square root of g/kg; p < 0.05), peak early transmitral velocity (b = -8.9 +/- 3.5 cm/s/square root of g/kg; p < 0.05), and peak atrial transmitral velocity (b = -4.9 +/- 1.9 cm/s/square root of g/kg; p < 0.05). No interactions with sex were observed.(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗