Search PubMed⌕ Search

Biomedical subjects

J N Bella

Publications and source records attributed to J N Bella.

27 records · Page 2Linked to original sources
PubMed2000

Left ventricular filling patterns in patients with systemic hypertension and left ventricular hypertrophy (the LIFE study). Losartan Intervention For Endpoint.

Abnormal left ventricular (LV) filling may exist in early stages of hypertension. Whether this finding is related to LV hypertrophy is currently controversial. This study was undertaken to assess relations between abnormal diastolic LV filling and LV geometry in a large series of hypertensive patients with electrocardiographic LV hypertrophy. M-mode, 2-dimensional, and pulsed Doppler echocardiographic recordings of mitral inflow velocity and isovolumetric relaxation time (IVRT) were obtained in 750 patients with stage I to III hypertension and LV hypertrophy determined by electrocardiography (sex-adjusted Cornell voltage duration criteria or Sokolow-Lyon voltage criteria) after 14 days of placebo treatment. The patients' mean age was 67+/-7 years and 44% were women. One hundred forty patients (19%) had normal LV geometric pattern, 79 (11%) had concentric remodeling, 342 (45%) had eccentric LV hypertrophy, and 189 (25%) had concentric LV hypertrophy. A normal LV filling pattern was found in 116 patients (16%), abnormal relaxation in 519 (69%), "pseudonormal" filling was found in 83 (11%), and a restrictive filling pattern in 32 (4%). Prolonged IVRT was associated with LV hypertrophy (p<0.01) as well as elevated relative wall thickness (p<0.05). A stronger difference (p<0.01) in IVRT was found between groups with and without LV hypertrophy. Multiple regression analysis revealed that increased LV mass correlated with prolonged IVRT, whereas LV mass and geometry were not associated with peak early LV filling velocity (E), peak atrial filling velocity (A) ratio or mitral valve E-peak deceleration time, although IVRT was found to be an independent correlate of E/A ratio and deceleration time. Thus, abnormal IVRT was highly prevalent in all LV geometric subgroups among hypertensive patients with electrocardiographic LV hypertrophy, even in those with normal LV geometry determined by echocardiography. We found that IVRT differed significantly among patient groups with different LV geometric patterns, primarily because of the association of IVRT to LV mass.

Aged↗
PubMed2000

Prevalence and correlates of aortic regurgitation in American Indians: the Strong Heart Study.

OBJECTIVES: We sought to determine the prevalence and correlates of aortic regurgitation (AR) in a population-based sample group. BACKGROUND: Concern over induction of AR by weight loss medication highlights the importance of assessing the prevalence and correlates of AR in unselected patient groups. METHODS: Aortic regurgitation was assessed by color flow Doppler echocardiography in 3,501 American Indian participants age 47 to 81 years during the second Strong Heart Study. RESULTS: Mild (1+) AR was present in 7.3%, 2+ AR in 2.4% and 3+ to 4+ AR in 0.3% of participants, more frequently in those > or =60 years old than in those <60 years old (14.4% vs. 5.8%, p<0.001); AR was unrelated to gender. Compared with participants without AR, those with mild AR had a lower body mass index (p<0.004) and higher systolic pressure (p<0.003). Participants with AR had larger aortic root diameters (3.6+/-0.4 vs. 3.4+/-0.4 cm, p<0.001), higher creatinine levels (1.3+/-1.3 vs. 1.0+/-1.0 mg/dl, p<0.001) and higher urine albumin/creatinine levels (3.6+/-2.3 vs. 3.3+/-2.0 log, p<0.001), as well as higher prevalences of aortic stenosis (AS) or mitral stenosis (MS) (p<0.001). Regression analysis showed that AR was independently related to older age and larger aortic roots (p<0.0001), AS and absence of diabetes (p = 0.002), MS (p = 0.003) and higher log urine albumin/creatinine (p = 0.005). CONCLUSIONS: Aortic regurgitation occurred in 10% of a sample group of middle-aged to older adults and was related to older age, larger aortic root diameter, aortic and mitral stenosis and albuminuria. There was no association of AR with being overweight and a negative association of AR with diabetes.

Aged↗
PubMed2000

Impact of different partition values on prevalences of left ventricular hypertrophy and concentric geometry in a large hypertensive population : the LIFE study.

Left ventricular (LV) hypertrophy and concentric remodeling have been defined by using a variety of indexation methods and partition values (PVs) for LV mass and relative wall thickness (RWT). The effects of these methods on the distribution of LV geometric patterns in hypertensive subjects remain unclear. Echocardiograms were obtained in 941 patients with stage I to III hypertension and LV hypertrophy by ECG. LV mass was calculated by using different methods of indexation for body size and different PVs to identify hypertrophy: LV mass/body surface area (g/m(2)) PV for men/women 116/104, 125/110, or 125/125; LV mass/height (g/m) PV 143/102 or 126/105; and LV mass/height(2.7) (g/m(2.7)) PV 51/51 or 49.2/46.7. RWT was calculated by either 2xend-diastolic posterior wall thickness (PWT)/end-diastolic LV internal dimension (LVID) or end-diastolic interventricular septum dimension+end-diastolic PWT/end-diastolic LVID. LV hypertrophy or remodeling was present in 63% to 86% of subjects, and LV hypertrophy was present in 42% to 77%. By any index, eccentric hypertrophy was the common LV geometric pattern. Use of interventricular septum dimension+PWT/LVID to calculate RWT slightly increased the prevalence of normal geometry and eccentric hypertrophy compared with the use of 2xPWT/LVID. Subjects with LV hypertrophy identified by only LV mass/height(2.7) PV 49.2/46.7 were more obese, whereas those identified by only LV mass/body surface area PV 116/104 were taller and thinner than those in the 2 concordant groups with or without LV hypertrophy by both criteria. By either criterion, there were no significant differences between different LV geometric patterns in clinical cardiovascular disease. Hypertensive patients with LV hypertrophy by ECG have a high prevalence of geometric abnormalities, especially eccentric hypertrophy, irrespective of method of indexation or PV. LV mass indexation by body surface area or height(2.7) identifies lean and obese subjects, respectively. We found no difference in prevalent cardiovascular disease in subjects identified by either criterion, suggesting a similar high risk.

Aged↗
PubMed1999

Reliability of echocardiographic assessment of left ventricular structure and function: the PRESERVE study. Prospective Randomized Study Evaluating Regression of Ventricular Enlargement.

OBJECTIVES: The study was done to evaluate reliability of echocardiographic left ventricular (LV) mass. BACKGROUND: Echocardiographic estimation of LV mass is affected by several sources of variability. METHODS: We assessed intrapatient reliability of LV mass measurements in 183 hypertensive patients (68% men, 65 +/- 9 years) enrolled in the Prospective Randomized Enalapril Study Evaluating Regression of Ventricular Enlargement (PRESERVE) trial after a screening echocardiogram (ECHO) showed LV hypertrophy. A second ECHO was repeated at randomization (45 +/- 25 days later). Two-dimensional (2D)-guided M-mode or 2D linear measurements of LV cavity and wall dimensions were verified by one experienced reader. RESULTS: Mean LV mass was similar at first and second ECHO (243 +/- 53 vs. 241 +/- 54 g) and showed high reliability as estimated by intraclass correlation coefficient (RHO) = 0.93. Within-patient 5th, 10th, 90th and 95th percentiles of between-study difference in LV mass were -32 g, -28 g, +25 g and +35 g. Mean LV mass fell less from the first to the second ECHO than expected from a formula to predict regression to the mean (2 +/- 19 vs. 17 +/- 12 g, p < 0.001). Reliability was also high for LV internal diameter (RHO = 0.87), septal (RHO = 0.85) and posterior wall thickness (RHO = 0.83). Substantial or moderate reliability was observed for measures of LV systolic function and diastolic filling (RHO from 0.71 to 0.57). CONCLUSIONS: Left ventricular mass had high reliability and little regression to the mean; between-study LV mass change of +/-35 g or +/-17 g had > or = 95% or > or = 80% likelihood of being true change.

Aged↗
PubMed1999

Relations of diastolic left ventricular filling to systolic chamber and myocardial contractility in hypertensive patients with left ventricular hypertrophy (The PRESERVE Study).

Abnormalities of left ventricular (LV) diastolic filling and stress-corrected midwall shortening (MWS) have been described in hypertensive patients with normal ejection fraction (EF). However, whether stress-corrected MWS parallels LV diastolic filling better than EF does remains uncertain. Blood pressure, body mass index, echocardiographic LV mass and LV geometry, EF and stress-corrected MWS, LV diastolic filling (peak E- and A-wave velocities, E-wave deceleration time, and atrial filling fraction) were evaluated in 212 hypertensive patients with LV hypertrophy enrolled in the Prospective Randomized Enalapril Study Evaluating Regression of Ventricular Enlargement study. LV structure, geometry, as well as LV diastolic filling, were compared between patients with reduced EF (<55%, n = 39, 18%) and those with normal EF (>55%) as well as between patients with reduced stress-corrected MWS (<89.2%, n = 31, 15%) and those with normal stress-corrected MWS (>89.2%). Patients with reduced EF had higher LV mass, eccentric LV geometry, and higher heart rate than those with normal EF, although they did not differ in age, blood pressure, or body mass index. LV filling pattern was also similar in those 2 groups. Patients with reduced stress-corrected MWS had higher atrial filling fraction, body mass index, heart rate, LV mass, and concentric geometry than those with normal stress-corrected MWS. Atrial filling fraction was negatively associated with stress-corrected MWS, but not with EF in multivariate models, independently of age, gender, heart rate, and body mass index. Thus, in hypertensive patients with LV hypertrophy, abnormal LV diastolic filling is more closely related to impaired myocardial contractility than to LV chamber EF.

Aged↗
PubMed1999

Assessment of arterial compliance by carotid midwall strain-stress relation in normotensive adults.

Examining left ventricular midwall as opposed to endocardial mechanics enhances understanding of left ventricular function in individuals with abnormal cardiac geometry. Accordingly, we used carotid ultrasound and applanation tonometry of arterial pressure to derive carotid midwall strain and its relation to carotid peak-systolic and end-diastolic stresses in 82 apparently normal, employed subjects (56 men, 26 women; median age, 47 years; 70% white; 21% overweight) with no evidence of coronary or valvular heart disease. Regression equations relating carotid luminal and midwall strain to the increment in carotid stress during systole (Deltacarotid stress) were used to predict strain for the observed Deltastress. Observed/predicted carotid luminal or midwall strain was calculated as a measure of carotid luminal or midwall strain for imposed stress, termed stress-corrected strain. Midwall carotid strain was similar in women and men but was negatively related to older age (r=-0.35, P=0.001) and higher body mass index (r=-0.31, P=0.005) and brachial and carotid blood pressure (r=-0.30 to -0.45, all P<0.01). The pulsatile change in arterial load, measured by Deltacarotid stress, was positively related to midwall strain (r=0. 44, P<0.001) more closely than was carotid luminal strain. Regression analyses revealed that carotid midwall strain was positively related to Deltastress, with additional negative relations to age and carotid diastolic diameter (all P<0.001). Stress-corrected carotid midwall strain was strongly and negatively correlated with midwall elastic modulus and Young's modulus (both r=-0.77, P<0.001), followed by elastic modulus (r=-0.74, P<0.001), midwall Young's modulus (r=-0.73, P<0.001), midwall stiffness index (r=-0.70, P<0.001), and stiffness index (r=-0.66, P<0.001). Thus, in normal adults, carotid midwall strain is unrelated to gender, is positively related to pulsatile carotid load as measured by Deltacarotid stress, and is negatively related to age, overweight, and standard measures of arterial stiffness.

Age Factors↗
PubMed1999

Assessment of arterial compliance by carotid midwall strain-stress relation in hypertension.

To elucidate the relations between arterial hypertrophy and compliance in hypertension, we studied 205 unmedicated hypertensive patients (129 men and 76 women) and 82 normotensive adults (56 men and 26 women) from an employed population by carotid ultrasound, noninvasive applanation tonometry, and echocardiography. Carotid midwall strain and circumferential stress were calculated at end diastole and peak systole. The relations of luminal and midwall strain to the increment in circumferential stress from end diastole to peak systole (Deltacarotid stress in normal subjects) were used to calculate ratios of observed/predicted carotid luminal and midwall strain. Mean stress-corrected luminal strain (82+/-26%) and midwall strain (78+/-23%) were lower (both P<0.001) in hypertensive patients than in normal adults. Stress-corrected luminal strain identified 14% of hypertensive patients with low arterial compliance, while stress-corrected midwall strain was low in 18% of patients. Patients with subnormal carotid midwall strain were older (61+/-12 versus 54+/-12 years, P<0.01) and had larger carotid diameters (6. 6+/-0.8 versus 5.7+/-0.8 mm, P=0.002) and higher brachial pulse pressures (71+/-25 versus 63+/-17 mm Hg, P<0.05) than other patients. Patients with arterial hypertrophy had lower stress-corrected midwall strain than those without hypertrophy (70+/-24% versus 79+/-23%, P=0.05), whereas no difference was observed in stress-corrected luminal strain (P=0.40). Stress-corrected midwall strain tended to be lower in patients with discrete atherosclerotic plaques than in those without (74+/-20% versus 79+/-24%, P=0.15). Compared with patients with normal left ventricular geometry, those with concentric hypertrophy had larger carotid diameters (6.6+/-0.7 versus 5.8+/-0.9 mm, P<0.05) and lower stress-corrected luminal strain (62+/-11% versus 85+/-25%, P<0.05) and midwall strain (59+/-10% versus 81+/-22%, P<0.05). Therefore, stress-corrected midwall strain identifies patients with reduced arterial compliance, increased arterial wall thickness, and abnormal left ventricular geometry better than conventional measures based on arterial lumen diameters.

Blood Pressure↗
PubMed1998

Relations of left ventricular mass to fat-free and adipose body mass: the strong heart study. The Strong Heart Study Investigators.

BACKGROUND: It is unclear whether increased left ventricular (LV) mass in overweight individuals is related to their adiposity or to greater fat-free mass (FFM). METHODS AND RESULTS: We compared echocardiographic LV mass to FFM and adipose body mass by bioelectric impedance and to anthropometric measurements in 3107 American Indian participants in the Strong Heart Study. In men and women, the relations of LV mass and FFM (r=0.37 and 0.38, P<0.001) were closer (P<0.05 to <0.001) than they were with adipose mass, waist/hip ratio, body mass index, systolic blood pressure, height, or height2.7. Regression analyses showed that in men LV mass had the strongest independent relation with FFM, followed by systolic blood pressure and age (all P<0.001); in women, LV mass was related to FFM more strongly than it was to systolic blood pressure, age (all P<0. 001), and diabetes (P=0.012). Adipose mass had no independent relation to LV mass. When waist/hip ratio or body mass index were substituted for adipose mass, LV mass was independently related to FFM (P<0.001) and body mass index (P=0.02) but not to waist/hip ratio in men and was independently related to FFM and waist/hip ratio (both P<0.001) but not to body mass index in women. Using 97.5 percentile gender-specific partitions for LV mass/FFM in reference individuals, we found that LV hypertrophy occurred in 20.8% of Strong Heart Study participants with hypertension, overweight, or diabetes compared with 10.5% and 16.7% by LV mass indexed for body surface area or height2.7. CONCLUSIONS: LV mass is more strongly related to FFM than to adipose mass, waist/hip ratio, body mass index, or height-based surrogates for lean body weight; LV mass/FFM criteria may increase sensitivity to detect LV hypertrophy.

Adipose Tissue↗