Search PubMed⌕ Search

Biomedical subjects

W P Laird

Publications and source records attributed to W P Laird.

11 recordsLinked to original sources
PubMed1979

Cardiovascular response to isometric exercise in normal adolescents.

The purpose of this study was to document the cardiovascular response to submaximal isometric handgrip (IHG) exercise in 32 normal adolescents. Left ventricular (LV) dimensions and systolic time intervals were recorded using echocardiography; blood pressure was measured by sphygmomanometry both at rest and during IHG exercise at 25% maximum contraction. This level of isometric exercise produced significant (p less than 0.001) increases in mean heart rate, systolic, diastolic and mean blood pressures. Despite this response LV diastolic and systolic dimensions remained unchanged during exercise; hence, stroke volume remained constant. Cardiac index increased by 22% (p less than 0.001) due to the increase in heart rate. Systemic vascular resistance did not change significantly. LV ejection indices, including shortening fraction, mean Vcf and systolic time intervals also remained unchanged, except for an increase in LV ejection time index (p less than 0.025). These data indicate that the cardiovascular response to submaximal isometric exercise in normal adolescents is similar to that reported in adults. This study demonstrates that sustained isometric stress testing in adolescents is safe and provides normal hemodynamic values.

Adolescent↗
PubMed1979

Hypertension screening in schools: results of the Dallas study.

The purpose of this study was to determine the prevalence of persistent blood pressure elevations in an eighth-grade population composed of three ethnic groups, and to determine the feasibility of using school health facilities for hypertension screening. Blood pressure was recorded in 10,641 subjects (90% of the total eighth-grade population) in the Dallas Independent School District. Blacks made up 46% of the population; non-Latin whites, 40.1%; and Latin-Americans, 13.9%. On the first blood pressure screening, 8.9% had systolic or diastolic pressures or both at or above the 95th percentile. Of those whose blood pressures were elevated on the first examination, 98.3% were reexamined. After the third examination, 1.2% continued to have systolic hypertension, and 0.37% diastolic hypertension. No student had diastolic pressure above 90 mm Hg on all three examinations. The prevalence of persistent hypertension was similar for the three ethnic groups. Analysis of variation in blood pressure measurements revealed that the school nurses introduced a relatively small increase in variability. These data indicate that although school screening initially identifies large numbers of students as having inconstant pressure elevations, subsequent follow-up examinations show that less than 2% have persistent hypertension.

Adolescent↗
PubMed1979

The frequency of pericardial effusions in bacterial meningitis.

Because of our experience with four cases of purulent pericarditis complicating bacterial meningitis during a 13-month period, we performed a prospective study to determine the frequency of this complication. Echocardiograms were done on 100 patients with bacterial meningitis. Small or moderate pericardial effusions were detected in 19 patients, but none had symptoms or signs related to the effusion. Pericardiocentesis was done in one infant; all the other effusions resolved spontaneously. Patients with effusion were significantly younger than those without this complication, but no other significant risk factors were identified. A literature survey indicated that symptomatic pericarditis occurs in fewer than 1% of patients with meningitis. Conversely, in series of cases of purulent pericarditis, associated meningitis was reported in 12% of patients. We concluded that pericardial infection is common in patients with meningitis but that it is usually of no clinical significance and resolves with antibiotic therapy.

Bacterial Infections↗
PubMed1979

Fatal Haemophilus influenzae endocarditis diagnosed by echocardiography in an infant.

A 1-year-old boy was admitted to the hospital with Haemophilus influenzae meningitis. On the second hospital day a heart murmur heard on admission seemed louder. No signs of congestive heart failure were present. An echocardiogram demonstrated a persistent echo-dense mass behind the anterior leaflet of the mitral valve. A presumptive diagnosis of endocarditis was made. After ten days of antibiotic treatment the child was considerably improved. Treatment was continued for endocarditis. Over the next several days the infant's condition deteriorated. On the 16th hospital day he died. Autopsy examination showed a large vegetation attached to the posterior mitral valve leaflet. Bacterial endocarditis caused by H influenzae is uncommon at any age and rare in children. Echocardiography provided a definitive diagnosis early in the hospital course of this patient.

Echocardiography↗
PubMed1979

Response of hypertensive adolescents to dynamic and isometric exercise stress.

Isometric handgrip and dynamic exercise stress tests were performed on 109 hypertensive and 74 normotensive subjects 14 to 17 years old. The hypertensive subjects had resting systolic or diastolic pressures persistently above the 95th percentile on four consecutive examinations. Blood pressures and ECGs were recorded during isometric handgrip (25% maximum effort for four minutes) and bicycle ergometry until the subject was exhausted. The hypertensive subjects increased systolic pressure by an average 16 mm Hg with isometric exercise and 53 mm Hg with dynamic exercise. Control subjects had similar pressure changes, averaging 18 and 54 mm Hg, respectively. During isometric handgrip stress, diastolic pressures increased 12 mm Hg in hypertensive subjects and 18 mm Hg in control subjects. Only two hypertensive adolescents developed systolic pressures exceeding 200 mm Hg during dynamic exercise stress, and none developed systolic pressures above 200 mm Hg during isometric exercise stress. None of the normotensive or hypertensive subjects developed cardiac arrhythmias and the prevalence of ST segment depression during maximal stress was less than 2% in both groups. Therefore, in adolescents with mild to moderate hypertension the risk of developing significant ECG or hemodynamic abnormalities during mild isometric or heavy dynamic exercise is small. We believe the decision to restrict physical activity of an adolescent with elevated pressures should be based on the development of abnormal ST segment depression, cardiac arrhythmias, or excessive blood pressures at the time of exercise stress testing.

Adolescent↗
PubMed1977

Echocardiography of premature infants with pulmonary disease: a noninvasive method for detecting large ductal left-to-right shunts.

Echocardiography was used to evaluate premature infants with large patent ductus arteriosus (PDA) shunts and proved lung disease. A PDA producing large left-to-right shunting also causes left atrial enlargement. Since the left atrial diameter (LAD), measured by ultrasound, normally varies with body size, its value was compared to that of the aortic root diameter (AO) to adjust for body size variations. In those infants with pulmonary disease but no significant PDA, the range of LAD/AO ratios was similar to that of the control group. In patients with a proved large PDA the ratios were significantly higher. The ultrasound ratio returned to normal in all cases following surgical ligation of the PDA.

Aorta↗
PubMed1976

Hepatic hemangiomatosis. Successful management by hepatic artery ligation.

Successful management of severe congestive heart failure secondary to a hepatic hemangioma was accomplished by ligation of the hepatic artery in a 2-month-old infant. In the two years since the operation, follow-up observations including liver biopsy and hepatic angiography have indicated complete regression of the tumor. This report provides reassurance that this procedure is effective in the prompt control of severe heart failure, as well as in safely providing time for the spontaneous regression of the vascular tumor.

Follow-Up Studies↗
PubMed1976

Staphylococcal septicemia: successful treatment of complications in a child.

A previously healthy 5-year-old girl developed staphylococcal septicemia. Initially, cardiovascular failure with mitral insufficiency and purulent pericarditis dominated the clinical picture. Peripheral thromboembolic phenomena, meningitis, osteomyelitis, and persistent septicemia were subsequently encountered during antimicrobial and surgical therapy. Although staphylococcal septicemia is a potentially lethal disorder, anticipation of its natural course and its possible complications should lead to more successful management.

Central Nervous System Diseases↗