Search PubMed⌕ Search

Biomedical subjects

D D Savage

Publications and source records attributed to D D Savage.

At least 91 records · Page 5Linked to original sources

Prevalence of submitral (anular) calcium and its correlates in a general population-based sample (the Framingham Study).

To obtain epidemiologic information on submitral calcium, 2,069 subjects in the original Framingham Study cohort (mean age 70 +/- 7 years) and 3,625 of the offspring of the cohort and their spouses (mean age 44 +/- 10 years) with adequate echocardiograms were evaluated. Submitral calcium was detected in 162 (2.8%) of the 5,694 subjects; greater than 90% of the subjects with such calcium came from the 40% of the study group greater than 59 years of age. Women were more than twice as likely to have such calcium as men. Age in both sexes, systolic blood pressure in men, and obesity in women were significantly and independently associated with submitral calcium. There was a 12-fold excess of atrial fibrillation in subjects with (20 of 162, 12%) compared with those without (53 of 5,532, 1%) submitral calcium.

Adult↗

Relation of hemodynamic load to left ventricular hypertrophy and performance in hypertension.

Left ventricular hypertrophy and dysfunction in patients with hypertension are often poorly related to the level of blood pressure. To evaluate the reasons for this, 100 untreated patients (44 +/- 14 years) with essential hypertension were studied using cuff blood pressure and quantitative echocardiography to measure left ventricular mass index and end-diastolic relative wall thickness as 2 indexes of left ventricular hypertrophy. Left ventricular hypertrophy, as measured by either left ventricular mass index or end-diastolic relative wall thickness, correlated weakly with all indexes of blood pressure including systolic, diastolic, and mean blood pressure (r = 0.16 to 0.32). In contrast, end-diastolic relative wall thickness, an index which assesses the severity of concentric hypertrophy, showed a closer direct relation with total peripheral resistance (r = 0.52 p less than 0.001) and a significant inverse relation with cardiac index (r = -0.47, p less than 0.001). Left ventricular performance as assessed by fractional systolic shortening of left ventricular internal dimensions was not significantly related to left ventricular mass index, blood pressure, or peak systolic wall stress, but declined significantly with increasing mean systolic wall stress (r = -0.42, p less than 0.001) and even more with increasing end-systolic wall stress (r = -0.71, p less than 0.001). It is concluded that in patients with hypertension (1) left ventricular hypertrophy is correlated only modestly with measurements of resting blood pressure; and (2) the classic pattern of concentric left ventricular hypertrophy, as measured by relative wall thickness, is more closely related to the "typical" hypertensive abnormality of elevated peripheral resistance, suggesting that these anatomic and hemodynamic changes may be pathophysiologically interdependent. Furthermore, left ventricular performance declines when the pressure overload in hypertension is not offset by compensating hypertrophy, allowing wall stresses to increase.

Adolescent↗

Prevalence and correlates of posterior extra echocardiographic spaces in a free-living population based sample (the Framingham study).

To obtain epidemiologic information on extra echocardiographic spaces immediately posterior to the left ventricular free wall, 2,028 subjects in the original Framingham cohort study (mean age 70 +/- 7 years) and 3,624 of the offspring of the cohort (and their spouses) (mean age 44 +/- 10 years) with adequate echocardiograms were evaluated. Extra echocardiographic spaces were detected in 370 (6.5%) of the 5,652 subjects. The prevalence ranged from less than 1% in subjects in the 20- to 30-year age decade to greater than 15% for those in their 80s. Extra echocardiographic spaces tended to be more common in subjects who were older, female, obese, more hypertensive, and who had higher blood sugar levels and higher low density lipoprotein cholesterol levels (measured 8 years earlier). The high prevalence of extra echocardiographic spaces and the independent association with age (cohort and offspring), obesity (cohort and male offspring), and ventricular septal hypertrophy (cohort and male offspring) is compatible with at least 2 hypotheses among others that should be tested: (1) Subepicardial fat may often masquerade as pericardial fluid producing a posterior extra echocardiographic space, especially in obese elderly subjects. (2) Small posterior extra echocardiographic spaces may often be early markers of subclinical hypertensive heart disease.

Adolescent↗

Risk factors for pulmonary embolism. The Framingham Study.

To assess potential long-term risk factors for major pulmonary embolism, 46 subjects from the Framingham Heart Study with autopsy-confirmed and clinically significant pulmonary embolism were identified in whom age, systolic blood pressure, cholesterol level, cigarette use, glucose level, Metropolitan relative weight, and varicose veins were ascertained at entry into the Study. These variables were compared among these 46 subjects, all 3,470 subjects in whom these variables were measured at the inception of the Study, and the 998 of these subjects who died within 26 years of follow-up. In multivariate analysis of subjects with autopsy-confirmed major pulmonary embolism and all subjects who died, only Metropolitan relative weight was significantly and independently associated with pulmonary embolism and only among women (p less than 0.001). These findings indicate that, in this cohort, increased adiposity in women is an important long-term factor for significant pulmonary embolism at autopsy. This raises the possibility that weight reduction in obese women may decrease the chances of pulmonary embolism.

Age Factors↗

Sudden unexpected death during ambulatory electrocardiographic monitoring. The Framingham Study.

This report documents the clinical and electrocardiographic events of sudden unexpected death in a 52-year-old man without known heart disease during ambulatory electrocardiographic monitoring. This death occurred two and a half hours after detailed noninvasive testing, including treadmill exercise, that was unrevealing. The sequence of S-T change suggesting epicardial injury, multiform ventricular premature depolarizations, and frequent and early cycle ventricular premature depolarizations followed by ventricular tachycardia-flutter-fibrillation precipitated by an early cycle ventricular premature depolarization were documented. The delay in cardiopulmonary resuscitation in this witnessed cardiac arrest punctuates the need for widespread dissemination of the skills of cardiopulmonary resuscitation.

Death, Sudden↗

HDL-cholesterol in a sample of black adults: the Framingham Minority Study.

A group of 100 adult black residents of Framingham, MA were examined and their plasma lipids were determined by the Framingham Heart Study Lipoprotein Laboratory. The age range of the participants was 20-69 yr, and the mean age was 42 yr for both sexes. The mean plasma total cholesterol, HDL-cholesterol (HDL-C), and triglyceride (TG) values for the 45 black men were 184,37.2, and 78 mg/dl, respectively. The corresponding levels for the 55 black women were 192,50.4, and 49. Even after adjusting for obesity, alcohol intake, and cigarette use, the HDL-C levels among the blacks were significantly lower (p less than 0.001) than the levels for Framingham white men and women. This black sample is more highly educated than black groups previously studied, and appears to be as active as the Framingham white sample. We conclude that this black population has quite low HDL-C levels, and the results suggest that the lipoprotein distributions in this group differ from those previously reported for blacks.

Activities of Daily Living↗

Epidemiologic features of chronic atrial fibrillation: the Framingham study.

In the Framingham Study 2325 men and 2866 women 30 to 62 years old at entry were followed biennially over 22 years for the development of chronic atrial fibrillation in relation to antecedent cardiovascular disease and risk factors. During surveillance, atrial fibrillation developed in 49 men and 49 women. The incidence rose sharply with age but did not differ significantly between the sexes. Overall, there was a 2.0 per cent chance that the disorder would develop in two decades. Atrial fibrillation usually followed the development of overt cardiovascular disease. Only 18 men and 12 women (31 per cent) had chronic atrial fibrillation in the absence of cardiovascular disease. Cardiac failure and rheumatic heart disease were the most powerful predictive precursors, with relative risks in excess of sixfold. Hypertensive cardiovascular disease was the most common antecedent disease, largely because of its frequency in the general population. Among the risk factors for cardiovascular disease, diabetes and electrocardiographic evidence of left ventricular hypertrophy were related to the occurrence of atrial fibrillation. The development of chronic atrial fibrillation was associated with a doubling of overall mortality and of mortality from cardiovascular disease.

Adult↗

Seizures down-regulate muscarinic cholinergic receptors in hippocampal formation.

Muscarinic cholinergic receptors (MCR) have been previously shown to decline in the hippocampal formation (HPF) of amygdala-kindled rats. Seizures have been proposed as the process responsible for this down-regulation. We now demonstrate similar down-regulation of MCR within HPF in 3 additional methods of inducing seizures: electroconvulsive shock, entorhinal kindling and entorhinal lesion. Two key parameters which causally link the MCR declines with seizures are their time course and reversal with anticonvulsants. The transient decline of MCR induced by entorhinal lesion-induced seizures parallels the time course established in amygdala kindling. Further, phenobarbital could block both these seizures and the MCR declines. Together, this supports the relationship of seizures causing the declines. We postulate that the MCR down-regulation represents an endogenous inhibitory response of neurons that are intensely and repeatedly depolarized during the seizures.

Amygdala↗

Kindled seizures selectively reduce a subpopulation of [3H]quinuclidinyl benzilate binding sites in rat dentate gyrus.

Amygdala-kindled seizures reduced significantly the total number of [3H]quinuclidinyl benzilate binding sites in both dentate and hippocampal gyri compared to electrode implanted unstimulated controls. Both high and low affinity carbachol displaceable binding site populations were significantly reduced in hippocampal gyrus. By contrast, a selective decline of low affinity sites was found in dentate gyrus membranes. The selectivity of the decline in dentate but not hippocampus gyrus underscores the specificity of this molecular response to amygdala-kindled seizures. We suggest that these receptor alterations underlie adaptive mechanisms which antagonize kindled epileptogenesis.

Animals↗

Prognostic significance of 24 hour ambulatory electrocardiographic monitoring in patients with hypertrophic cardiomyopathy: a prospective study.

The prevalence and prognostic significance of ventricular arrhythmias identified on 24 hour ambulatory electrocardiographic monitoring was prospectively assessed in 99 patients with hypertrophic cardiomyopathy. In the absence of antiarrhythmic therapy, high grade ventricular arrhythmias (grade 3 and above) were common; that is they were identified in 66 percent of the patients, including 19 percent with episodes of asymptomatic ventricular tachycardia. Clinical outcome was assessed 3 years after the initial 24 hour ambulatory electrocardiogram. Of the 84 patients who did not undergo ventricular septal myotomy-myectomy, 6 died suddenly or experienced cardiac arrest, 1 died of progressive congestive heart failure and the other 77 have survived without a cardiac catastrophe. The prevalence rate of sudden death or cardiac arrest during the follow-up period was the same (3 percent) in patients with high grade arrhythmias other than ventricular tachycardia (1 of 37) as in those with no or low grade arrhythmias (1 of 29). However, the occurrence of a sudden cardiac catastrophe was significantly more common in patients with asymptomatic ventricular tachycardia of brief duration on 24 hour electrocardiography (4 [24 percent] of 17) than in patients without ventricular tachycardia (2 [3 percent] of 66) (p less than 0.02). In summary, (1) high grade ventricular arrhythmias are commonly found on continuous 24 hour electrocardiography monitoring in patients with hypertrophic cardiomyopathy; and (2) although sudden death is relatively uncommon in patients with high grade ventricular arrhythmias other than ventricular tachycardia (annual mortality rate 1 percent), the finding of ventricular tachycardia on 24 hour electrocardiography identifies a subgroup of patients at high risk for sudden death (annual mortality rate 8.6 percent). Although no conclusions can be drawn regarding the impact of therapy, our findings suggest that 24 hour electrocardiographic monitoring should be performed in patients with hypertrophic cardiomyopathy and that it may be reasonable to initiate antiarrhythmic therapy if ventricular tachycardia is identified.

Adolescent↗

Monoamine oxidase inhibitors and serotonin uptake inhibitors: differential effects on [3H]serotonin binding sites in rat brain.

Rats were administered either monoamine oxidase inhibitors or serotonin uptake inhibitors for either 1, 4 or 16 days. The binding of [3H]serotonin to brain homogenates and the concentration of serotonin in brain was measured at these times. Treatment with inhibitors of serotonin uptake did not change the specific binding of [3H]serotonin in either cerebral cortex or hippocampus, nor did it produce any consistent alterations in the concentration of serotonin in the cerebral cortex. In contrast, monoamine oxidase inhibitors capable of inhibiting A-type monoamine oxidase significantly decreased [3H]serotonin binding after both 4 and 16 days of treatment; serotonin concentrations were significantly elevated at all time intervals. Inhibitors of B-type monoamine oxidase had no effect on either [3H]serotonin binding or serotonin concentrations in cerebral cortex. The reduction in labeled serotonin binding caused by monoamine oxidase inhibitors is due to a decrease in the maximum number of specific binding sites with no change in the affinity of the binding sites for labeled serotonin.

Amitriptyline↗