Biomedical subjects

K M Finta

Publications and source records attributed to K M Finta.

7 recordsLinked to original sources

PubMed1994

Systemic ventricular outflow obstruction progresses after the Fontan operation.

To evaluate the course of systemic ventricular outflow obstruction after the Fontan operation, the records of 57 hospital survivors of that procedure were reviewed. Ventricular outflow obstruction was identified in 7 patients (group 1) and was absent in 50 patients (group 2). Overall, the ventricular outflow gradient in group 1 was 6.3 +/- 2.9 mm Hg (mean +/- standard error) before the Fontan operation and 7.6 +/- 3.9 mm Hg at hospital discharge. Ventricular outflow obstruction subsequently progressed to 80.1 +/- 17.3 mm Hg (range, 33 to 165 mm Hg; p < 0.02) a mean of 28 months postoperatively. One patient died of severe progressive ventricular outflow obstruction. Group 1 did not differ from group 2 in age, ventricular morphology, presence of a subaortic outflow chamber, prior shunt, or length of follow-up. Compared with group 2, however, patients in group 1 more commonly had an aorta arising from a hypoplastic ventricle (p < 0.001) and had undergone prior pulmonary artery banding (p = 0.005). We conclude that systemic ventricular outflow obstruction occurs commonly after a Fontan procedure (incidence, 12%; 70% confidence interval, 9% to 18%) and is a progressive lesion.

Child, Preschool↗

PubMed1994

Enhanced vascular responsiveness to Bay K 8644 in mineralocorticoid- and N-nitro arginine-induced hypertension.

The present study evaluates the response to the L-type voltage gated calcium channel agonist Bay K 8644 in two forms of experimental hypertension (mineralocorticoid- and hypertension induced by the nitric oxide synthase inhibitor N omega-nitro-L-arginine (N-Nitro arginine)) and under conditions of acute stretch. These studies test the hypothesis that increased L-type calcium channel activity in vasculature is a hallmark or general characteristic of hypertension. Male Sprague-Dawley rats were made hypertensive by subcutaneous implantation of deoxycorticosterone acetate (200 mg/kg DOCA) and given normal or high salt water (1% NaCl + 0.2% KCl); other rats were made hypertensive by ingestion of N-Nitro arginine (2% in water). Systolic blood pressures (SBP) were taken by the standard tail cuff method. Following development of hypertension, rats were anesthetized, and aortae or mesenteric arteries were isolated for measurement of isometric contractile force. Cumulative concentration response curves to Bay K 8644 (10(-10) to 10(-6) M), KCl (6 to 100 mM), or phenylephrine (10(-10)-3 x 10(-7) M) were evaluated. Isolated mesenteric arteries from rats given both DOCA and salt were most sensitive to Bay K 8644 (SBP = 191 +/- 6 mmHg, -log EC50 = 7.78 +/- 0.13), followed by rats receiving high salt alone (SBP = 118 +/- 6 mmHg, -log EC50 = 7.30 +/- 0.17), DOCA alone (SBP = 152 +/- 2 mmHg, -log EC50 = 7.25 +/- 0.15), and finally normal sham rats (SBP = 111 +/- 5 mm Hg, -log EC50 > or = 6.80 +/- 0.10). These data indicate that both DOCA and salt intake can independently influence responsiveness to Bay K 8644.(ABSTRACT TRUNCATED AT 250 WORDS)

3-Pyridinecarboxylic acid, 1,4-dihydro-2,6-dimethy↗

PubMed1993

Ramipril prevents impaired endothelium-dependent relaxation in arteries from rabbits fed an atherogenic diet.

Endothelium-dependent relaxation in arteries is attenuated in clinical and experimental atherosclerosis. This study investigates the endothelial preservation properties of the angiotensin converting enzyme inhibitor, ramipril, by assessing its ability to restore endothelium-dependent responsiveness in blood vessels from rabbits fed an atherogenic diet (0.25% cholesterol; 3% coconut oil; 12 weeks). Seven rabbits fed the atherogenic diet received ramipril (3 mg/kg mixed into their food daily) and 6 rabbits were maintained on the atherogenic diet alone. Control rabbits (n = 6) were fed a standard diet and did not receive ramipril. At the end of the dietary intervention, the rabbits were killed and blood was collected for measurement of the lipid profile. The thoracic aorta was isolated and half was frozen for pathologic review while the other half was cut into rings and placed in a muscle bath for measurement of isometric force development. Dose response curves to phenylephrine (10(-9) to 10(-5) M) and angiotensin II (10(-10) to 3 x 10(-7) M) were completed. There was a minimal decrease in responsiveness to phenylephrine in vessels from rabbits eating the atherogenic diet compared with controls and no significant differences in the response to angiotensin II for any of the vessels. Following contraction by phenylephrine, acetylcholine (10(-9) to 10(-5) M) and nitroglycerin (10(-10) to 10(-5) M) dose response curves were completed. Relaxation to acetylcholine in aortic rings from control rabbits was observed, although in arteries from atherogenic rabbits relaxation was attenuated. This effect was prevented in the atherogenic rabbits fed ramipril. Responsiveness to the endothelium-independent vasodilator, nitroglycerin, was similar in arteries from the three rabbit groups.(ABSTRACT TRUNCATED AT 250 WORDS)

Acetylcholine↗

PubMed1993

Cardiovascular manifestations of hypertension in children.

Hypertension has its roots in childhood. Electrocardiographic, echocardiographic, and exercise testing in young patients point to early abnormalities of cardiovascular status in children with early hypertensive disease. Altered morphology of the cardiovascular system and vascular reactivity is also seen in the hypertensive or prehypertensive child. Perhaps investigation and preventive tactics may be best applied to the pediatric population.

Cardiovascular Diseases↗

PubMed1992

Perceived exertion and exercise intensity in children with or without structural heart defects.

To assess the ability of children with cardiac disease to quantify their effort during exercise with the Borg perceived exertion scale, and to determine the validity of the scale for use with children by comparing the ratings with direct measurements of exercise intensity, we exercised 36 children with various cardiac defects and 15 normal children to exhaustion with the Bruce treadmill protocol. The subjects were able to quantify exercise intensity, so perceived exertion ratings can be used to predetermine the level of exercise intensity in an unmonitored setting and may be useful in defining appropriate exercise programs.

Adolescent↗

PubMed1992

Forearm resistance vessel abnormalities and insulin resistance in obese adolescents.

To determine if structural changes in forearm resistance vessels are associated with insulin resistance, we evaluated the relation between minimum forearm vascular resistance and insulin resistance in 95 obese adolescents before and after weight loss. Insulin resistance was assessed by fasting insulin levels and sum of insulin values after an oral glucose tolerance test in all 95 subjects and whole body glucose uptake during euglycemic hyperinsulinemia in 35 of 95 subjects. Structural changes in forearm vessels were assessed by measurement of minimum forearm vascular resistance during 10 minutes of ischemic exercise. As compared with our normal values, obese adolescents had a significantly (p less than 0.01) decreased maximal forearm blood flow (41.6 +/- 1.4 versus 67.1 +/- 2.4 ml/min/100 ml) and increased minimum forearm vascular resistance (2.9 +/- 0.4 versus 1.6 +/- 0.7 mm Hg/ml/min/100 ml). There was a significant relation (p less than 0.01) between minimum forearm vascular resistance and fasting insulin, sum of insulins, and whole body glucose uptake. After a 20-week weight-loss program, minimum forearm vascular resistance decreased (3.0 +/- 0.3 versus 2.0 +/- 0.2, p less than 0.01), maximal forearm blood flow increased (41 +/- 2.3 versus 57.4 +/- 3.9, p less than 0.01), and forearm volume remained unchanged. We also observed a significant (p less than 0.01) relation between the decrease in minimum forearm vascular resistance and the decrease in fasting insulin (r = 0.29), decrease in sum of insulins (r = 0.42), and increase in whole body glucose uptake (r = 0.63).(ABSTRACT TRUNCATED AT 250 WORDS)

Adult↗

PubMed1992

Urine sodium excretion in response to an oral glucose tolerance test in obese and nonobese adolescents.

To determine if physiologic changes of insulin are capable of inducing sodium retention in insulin-resistant patients, we evaluated the ability of an oral glucose tolerance test to alter urine sodium excretion in 32 obese subjects (13.3 +/- 1 years, weight 82 +/- 5 kg, mean arterial pressure 89.3 +/- 1.5 mm Hg) and 13 nonobese subjects (13.8 +/- 2 years, weight 46 +/- 4 kg, mean arterial pressure 74.5 +/- 2.6 mm Hg). After an overnight fast, subjects were placed in water diuresis and fasting insulin and glucose levels were drawn. Three 30-minute urine collections were obtained for baseline urine sodium excretion. The oral glucose tolerance test was administered with glucose and insulin levels drawn at 15, 30, 45, 60, 90, and 120 minutes. During the oral glucose tolerance test, four 30-minute urine collections were obtained for urine sodium excretion. Serum glucose levels at baseline and throughout the glucose tolerance test did not differ between obese and nonobese subjects. Baseline insulin levels were elevated significantly in the obese (20 +/- 3 microU/mL) compared with the nonobese (5 +/- 0.7 microU/mL) subjects. Furthermore, insulin levels remained significantly elevated in the obese subjects compared with the nonobese subjects throughout the glucose tolerance test (118 +/- 19 vs 49 +/- 6 microU/mL, obese vs nonobese subjects at 1-hour post-glucose tolerance test).(ABSTRACT TRUNCATED AT 250 WORDS)

Adolescent↗